Populations of African ancestry continue to account for a disproportionate burden of human immunodeficiency virus type 1 (HIV-1) epidemic in the US. We investigated the effects of human leukocyte antigen (HLA) class I markers in association with virologic and immunologic control of HIV-1 infection among 338 HIV-1 subtype B-infected African Americans in two cohorts: REACH (Reaching for Excellence in Adolescent Care and Health) and HERS (HIV Epidemiology Research Study). One-year treatment-free interval measurements of HIV-1 RNA viral loads and CD4+ T-cells were examined both separately and combined to represent three categories of HIV-1 disease control (76 “controllers,” 169 “intermediates,” and 93 “non-controllers”). Certain previously or newly implicated HLA class I alleles (A*32, A*36, A*74, B*14, B*1510, B*3501, B*45, B*53, B*57, Cw*04, Cw*08, Cw*12, and Cw*18) were associated with one or more of the endpoints in univariate analyses. After multivariable adjustments for other genetic and non-genetic risk factors of HIV-1 progression, the subset of alleles more strongly or consistently associated with HIV-1 disease control included A*32, A*74, B*14, B*45, B*53, B*57, and Cw*08. Carriage of infrequent HLA-B but not HLA-A alleles was associated with more favorable disease outcomes. Certain HLA class I associations with control of HIV-1 infection span the boundaries of race and viral subtype; while others appear confined within one or the other of those boundaries.
HLA class I; Allele frequency; HIV-1 control; African American
Prostate cancer is a heterogenous disease with a variable natural history that is not accurately predicted by currently used prognostic tools.
We genotyped 798 prostate cancer cases of Ashkenazi Jewish ancestry treated for localized prostate cancer between June 1988 and December 2007. Blood samples were prospectively collected and de-identified before being genotyped and matched to clinical data. The survival analysis was adjusted for Gleason score and PSA. We investigated associations between 29 single nucleotide polymorphisms (SNPs) and biochemical recurrence, castration-resistant metastasis, and prostate cancer-specific survival. Subsequently, we performed an independent analysis using a high resolution panel of 13 SNPs.
On univariate analysis, 2 SNPs were associated (p<0.05) with biochemical recurrence; 3 SNPs were associated with clinical metastases; and 1 SNP was associated with prostate cancer-specific mortality. Applying a Bonferroni correction (p<0.0017), one association with biochemical recurrence (p=0.0007) was significant. Three SNPs showed associations on multivariable analysis, although not after correcting for multiple testing. The secondary analysis identified an additional association with prostate cancer-specific mortality in KLK3 (p<0.0005 by both univariate and multivariable analysis).
We identified associations between prostate cancer susceptibility SNPs and clinical endpoints. The rs61752561 in KLK3 and rs2735839 in the KLK2-KLK3 intergenic region associated strongly with prostate cancer-specific survival, and rs10486567 in 7JAZF1 gene associated with biochemical recurrence. A larger study will be required to independently validate these findings and determine the role of these SNPs in prognostic models.
Single nucleotide polymorphisms; Prostate cancer; Prognosis
Increased prostate cancer risk has been reported for BRCA mutation carriers but BRCA-associated clinicopathologic features have not been clearly defined.
We determined BRCA mutation prevalence in 832 Ashkenazi Jewish (AJ) men diagnosed with localized prostate cancer between 1988 and 2007 and 454 AJ controls, and compared clinical outcome measures among 26 BRCA mutation carriers and 806 non-carriers. Kruskal-Wallis tests were used to compare age of diagnosis and Gleason Score (GS), and logistic regression models to determine associations between carrier status, prostate cancer risk, and GS. Hazard ratios for clinical endpoints were estimated using Cox proportional hazards models.
BRCA2 mutations were associated with a threefold risk of prostate cancer (OR [95% CI]=3.18 [1.52-6.66]; p = 0.002), and presented with more poorly differentiated (GS ≥ 7) tumors(85% vs. 57%, p= 0.0002) compared with non-BRCA associated PC. BRCA1 mutations conferred no increased risk. After 7,254 person-years of follow-up, and adjusting for clinical stage, PSA, GS, and treatment, BRCA2 and BRCA1 mutation carriers had a higher risk of recurrence (HR [95% CI] = 2.41[1.23, 4.75] and 4.32 [1.31, 13.62], respectively) and prostate cancer -specific death (HR [95% CI] = 5.48 [2.03, 14.79] and 5.16 [1.09,24.53], respectively) than non-carriers.
BRCA2 mutation-carriers had an increased risk of prostate cancer and a higher histological grade, and BRCA1 or BRCA2 mutations were associated with a more aggressive clinical course. These results may have impact on tailoring clinical management of this subset of hereditary prostate cancer.
BRCA1; BRCA2; prostate cancer; clinicopathologic associations
To explore the effects of single nucleotide polymorphisms (SNPs) on pancreatic cancer risk and overall survival.
The germline DNA of 531 pancreatic cancer cases and 305 healthy controls from a hospital-based study was genotyped at SNPs previously reported to be associated with pancreatic cancer risk or clinical outcome. We analyzed putative risk SNPs for replication of their reported effects on risk and tested for novel effects on overall survival (OS). Similarly, we analyzed putative survival-associated SNPs for replication of their reported effects on OS and tested for novel effects on risk. Lastly, we performed a genome-wide association study of OS using a subset of 252 cases, with two subsequent validation sets of 261 and 572 patients, respectively.
Among seven risk SNPs analyzed, two (rs505922, rs9543325) were associated with risk (p<0.05). Among 24 survival-associated SNPs analyzed, one (rs9350) was associated with OS (p<0.05). No putative risk SNPs or putative survival-associated SNPs were found to be associated with OS or risk, respectively. Further, our GWAS identified a novel SNP (rs1482426, combined stage 1 and 2 p = 1.7 ×10−6, per-allele HR = 1.74, 95% CI 1.38–2.18) to be putatively associated with OS.
The effects of SNPs on pancreatic cancer risk and overall survival were replicated in our study, though further work is necessary to understand the functional mechanisms underlying these effects. More importantly, the putative association with OS identified by GWAS suggests that GWAS may be useful in identifying SNPs associated with clinical outcome in pancreatic cancer.
pancreatic cancer; susceptibility; overall survival; genome-wide association study (GWAS)
Polycythemia vera, essential thrombocythemia and primary myelofibrosis are myeloproliferative neoplasms (MPN) characterized by multilineage clonal hematopoiesis1–5. Given that the identical somatic activating mutation in the JAK2 tyrosine kinase gene (JAK2V617F) is observed in most individuals with polycythemia vera, essential thrombocythemia and primary myelofibrosis6–10, there likely are additional genetic events that contribute to the pathogenesis of these phenotypically distinct disorders. Moreover, family members of individuals with MPN are at higher risk for the development of MPN, consistent with the existence of MPN predisposition loci11. We hypothesized that germline variation contributes to MPN predisposition and phenotypic pleiotropy. Genome-wide analysis identified an allele in the JAK2 locus (rs10974944) that predisposes to the development of JAK2V617F-positive MPN, as well as three previously unknown MPN modifier loci. We found that JAK2V617F is preferentially acquired in cis with the predisposition allele. These data suggest that germline variation is an important contributor to MPN phenotype and predisposition.
Latino children of Caribbean descent remain at high risk for poorly controlled asthma. Controller medications improve asthma control; however, medication adherence remains suboptimal, particularly among minorities. This study assessed socioeconomic, family-based, and parent factors in medication adherence among children with asthma from Rhode Island (RI; Latino and non-Latino white [NLW]) and Puerto Rico.
Data collection occurred as part of a multicenter study of asthma disparities. Our sample included children (ages 7–16) prescribed objectively monitored controller medications (n = 277; 80 island Puerto Rico, 114 RI Latino, 83 RI NLW). Parents completed questionnaires regarding family background and beliefs about medications. Families participated in an interview regarding asthma management. Multilevel analyses (maximum likelihood estimates) accounting for children being nested within site and ethnic group assessed the contribution of social context, family, and parent variables to medication adherence.
Medication adherence differed by ethnic group (F2, 271 = 7.46, P < .01), with NLW families demonstrating the highest levels of adherence. Multilevel models indicated that parental beliefs about medication necessity and family organization regarding medication use were significant predictors of adherence, even for families below the poverty threshold. With family factors in the model, a substantial improvement in model fit occurred (Akaike Information Criterion change of 103.45).
Adherence to controller medications was lower among Latino children in our sample. Targeted interventions that capitalize on existing family resources, emphasize structure, and address parental beliefs about the importance of medications may be of benefit to families from different cultural backgrounds.
asthma; patient nonadherence; disparities
Approximately 80% of children with asthma have coexisting allergic rhinitis. The accurate recognition and assessment of asthma and rhinitis symptoms is an integral component of guideline-based treatment for both conditions. This article describes the development and preliminary evaluation of a novel paradigm for testing the accuracy of children's assessment of their upper airway (rhinitis) symptoms. This work is guided by our previous research showing the clinical efficacy of tools to evaluate children's perceptual accuracy of asthma symptoms and linking accurate asthma symptom perception to decreased asthma morbidity (Fritz G, et al., Ethnic differences in perception of lung function: A factor in pediatric asthma disparities? Am J Respir Crit Care Med 182:12–18, 2010; Klein RB, et al., The Asthma Risk Grid: Clinical interpretation of symptom perception, Allergy Asthma Proc 251–256, 2004). The pilot study tests a paradigm that allows for the examination of the correspondence of children's assessment of their upper airway functioning with actual values of upper airway flow through the use of a portable, handheld nasal peak flowmeter. Nine children with persistent asthma were evaluated over a 4-week period. The article describes the rhinitis perceptual accuracy paradigm and reviews the results of a pilot study, showing a large proportion of inaccurate rhinitis symptoms “guesses” by the sample of children with persistent asthma. Patterns of inaccuracy, rhinitis control, and asthma morbidity are also described. Directions for future work are reviewed. The development of clinical tools to evaluate children's accuracy of rhinitis symptoms are needed, given the central role of the self-assessment of symptoms in guideline-based care. Accurate perception of the severity of rhinitis symptoms may enhance rhinitis control, lessen the burden of asthma, and prevent unnecessary emergency use among this high-risk group of children.
Allergy; asthma; children; perceptual accuracy; rhinitis; treatment; upper airway
Objective The goal of this study is to identify individual, family/cultural, and illness-related protective factors that may minimize asthma morbidity in the context of multiple urban risks in a sample of inner-city children and families. Methods Participating families are from African-American (33), Latino (51) and non-Latino white (47) backgrounds. A total of 131 children with asthma (56% male), ages 6–13 years and their primary caregivers were included. Results Analyses supported the relationship between cumulative risks and asthma morbidity across children of the sample. Protective processes functioned differently by ethnic group. For example, Latino families exhibited higher levels of family connectedness, and this was associated with lower levels of functional limitation due to asthma, in the context of risks. Conclusions This study demonstrates the utility of examining multilevel protective processes that may guard against urban risks factors to decrease morbidity. Intervention programs for families from specific ethnic groups can be tailored to consider individual, family-based/cultural and illness-related supports that decrease stress and enhance aspects of asthma treatment.
asthma outcomes; cultural factors; inner city; pediatric asthma; protective factors
To facilitate the mapping of genes in sorghum [Sorghum bicolor (L.) Moench] underlying economically important traits, we analyzed the genetic structure and linkage disequilibrium in a sorghum mini core collection of 242 landraces with 13,390 single-nucleotide polymorphims. The single-nucleotide polymorphisms were produced using a highly multiplexed genotyping-by-sequencing methodology. Genetic structure was established using principal component, Neighbor-Joining phylogenetic, and Bayesian cluster analyses. These analyses indicated that the mini-core collection was structured along both geographic origin and sorghum race classification. Examples of the former were accessions from Southern Africa, East Asia, and Yemen. Examples of the latter were caudatums with widespread geographical distribution, durras from India, and guineas from West Africa. Race bicolor, the most primitive and the least clearly defined sorghum race, clustered among other races and formed only one clear bicolor-centric cluster. Genome-wide linkage disequilibrium analyses showed linkage disequilibrium decayed, on average, within 10−30 kb, whereas the short arm of SBI-06 contained a linkage disequilibrium block of 20.33 Mb, confirming a previous report of low recombination on this chromosome arm. Four smaller but equally significant linkage disequilibrium blocks of 3.5−35.5 kb were detected on chromosomes 1, 2, 9, and 10. We examined the genes encoded within each block to provide a first look at candidates such as homologs of GS3 and FT that may indicate a selective sweep during sorghum domestication.
sorghum; races; SNPs; FseI-assisted genotyping; linkage disequilibrium
Common genetic variants contribute to the observed variation in breast cancer risk for BRCA2 mutation carriers; those known to date have all been found through population-based genome-wide association studies (GWAS). To comprehensively identify breast cancer risk modifying loci for BRCA2 mutation carriers, we conducted a deep replication of an ongoing GWAS discovery study. Using the ranked P-values of the breast cancer associations with the imputed genotype of 1.4 M SNPs, 19,029 SNPs were selected and designed for inclusion on a custom Illumina array that included a total of 211,155 SNPs as part of a multi-consortial project. DNA samples from 3,881 breast cancer affected and 4,330 unaffected BRCA2 mutation carriers from 47 studies belonging to the Consortium of Investigators of Modifiers of BRCA1/2 were genotyped and available for analysis. We replicated previously reported breast cancer susceptibility alleles in these BRCA2 mutation carriers and for several regions (including FGFR2, MAP3K1, CDKN2A/B, and PTHLH) identified SNPs that have stronger evidence of association than those previously published. We also identified a novel susceptibility allele at 6p24 that was inversely associated with risk in BRCA2 mutation carriers (rs9348512; per allele HR = 0.85, 95% CI 0.80–0.90, P = 3.9×10−8). This SNP was not associated with breast cancer risk either in the general population or in BRCA1 mutation carriers. The locus lies within a region containing TFAP2A, which encodes a transcriptional activation protein that interacts with several tumor suppressor genes. This report identifies the first breast cancer risk locus specific to a BRCA2 mutation background. This comprehensive update of novel and previously reported breast cancer susceptibility loci contributes to the establishment of a panel of SNPs that modify breast cancer risk in BRCA2 mutation carriers. This panel may have clinical utility for women with BRCA2 mutations weighing options for medical prevention of breast cancer.
Women who carry BRCA2 mutations have an increased risk of breast cancer that varies widely. To identify common genetic variants that modify the breast cancer risk associated with BRCA2 mutations, we have built upon our previous work in which we examined genetic variants across the genome in relation to breast cancer risk among BRCA2 mutation carriers. Using a custom genotyping platform with 211,155 genetic variants known as single nucleotide polymorphisms (SNPs), we genotyped 3,881 women who had breast cancer and 4,330 women without breast cancer, which represents the largest possible, international collection of BRCA2 mutation carriers. We identified that a SNP located at 6p24 in the genome was associated with lower risk of breast cancer. Importantly, this SNP was not associated with breast cancer in BRCA1 mutation carriers or in a general population of women, indicating that the breast cancer association with this SNP might be specific to BRCA2 mutation carriers. Combining this BRCA2-specific SNP with 13 other breast cancer risk SNPs also known to modify risk in BRCA2 mutation carriers, we were able to derive a risk prediction model that could be useful in helping women with BRCA2 mutations weigh their risk-reduction strategy options.
Although case-control studies have identified numerous single nucleotide polymorphisms (SNPs) associated with prostate cancer, the clinical role of these SNPs remains unclear.
Evaluate previously identified SNPs for association with prostate cancer and accuracy in predicting prostate cancer in a large prospective population-based cohort of unscreened men.
Design, setting, and participants
This study used a nested case-control design based on the Malmö Diet and Cancer cohort with 943 men diagnosed with prostate cancer and 2829 matched controls. Blood samples were collected between 1991 and 1996, and follow-up lasted through 2005.
We genotyped 50 SNPs, analyzed prostate-specific antigen (PSA) in blood from baseline, and tested for association with prostate cancer using the Cochran-Mantel-Haenszel test. We further developed a predictive model using SNPs nominally significant in univariate analysis and determined its accuracy to predict prostate cancer.
Results and limitations
Eighteen SNPs at 10 independent loci were associated with prostate cancer. Four independent SNPs at four independent loci remained significant after multiple test correction (p < 0.001). Seven SNPs at five independent loci were associated with advanced prostate cancer defined as clinical stage ≥T3 or evidence of metastasis at diagnosis. Four independent SNPs were associated with advanced or aggressive cancer defined as stage ≥T3, metastasis, Gleason score ≥8, or World Health Organization grade 3 at diagnosis. Prostate cancer risk prediction with SNPs alone was less accurate than with PSA at baseline (area under the curve of 0.57 vs 0.79), with no benefit from combining SNPs with PSA. This study is limited by our reliance on clinical diagnosis of prostate cancer; there are likely undiagnosed cases among our control group.
Only a few previously reported SNPs were associated with prostate cancer risk in the large prospective Diet and Cancer cohort in Malmö, Sweden. SNPs were less useful in predicting prostate cancer risk than PSA at baseline.
Prostate cancer; Biomarkers; SNPs; PSA; Sensitivity and specificity
Atopic diseases, such as asthma and allergic rhinitis, are common conditions that can influence sleep and subsequent daytime functioning. Children and patients with allergic conditions from ethnic minority groups might be particularly vulnerable to poor sleep and compromised daytime functioning because of the prevalence of these illnesses in these groups and the high level of morbidity. Research over the past 10 years has shed light on the pathophysiologic mechanisms (eg, inflammatory mediators) involved in many atopic diseases that can underlie sleep disruptions as a consequence of the presence of nocturnal symptoms. Associations between nocturnal symptoms and sleep and poorer quality of life as a result of missed sleep have been demonstrated across studies. Patients with severe illness and poor control appear to bear the most burden in terms of sleep impairment. Sleep-disordered breathing is also more common in patients with allergic diseases. Upper and lower airway resistance can increase the risk for sleep-disordered breathing events. In patients with allergic rhinitis, nasal congestion is a risk factor for apnea and snoring. Finally, consistent and appropriate use of medications can minimize nocturnal asthma or allergic symptoms that might disrupt sleep. Despite these advances, there is much room for improvement in this area. A summary of the sleep and allergic disease literature is reviewed, with methodological, conceptual, and clinical suggestions presented for future research.
Sleep; allergic disease; asthma; allergic rhinitis; atopic dermatitis
HIV infection has been associated with development of prediabetes and diabetes. Optimum screening practices for these disorders in HIV-infected populations remain unclear.
We screened 377 adults, with- or at-risk for HIV infection, for incident hyperglycaemia (prediabetes or diabetes) using two oral glucose tolerance tests (OGTTs) a median of 18.6 months apart. We determined proportion of incident cases detected by fasting and 120-min plasma glucose levels. Independent predictors of incident hyperglycaemia were identified using logistic regression.
The baseline OGTT was consistent with diabetes in 7% of participants and with prediabetes in 31%. Among 352 normoglycaemic and prediabetic participants at baseline, 19 (5%) developed diabetes on follow-up. Among participants normoglycaemic at baseline, an additional 38 (16%) developed prediabetes. Overall 52% of incident hyperglycaemia cases were detected by fasting plasma glucose alone, 33% by a 120-min glucose level alone and 15% by both. Factors independently associated with incident hyperglycaemia included age ≥50 years and body mass index ≥30 kg/m2. Neither HIV infection nor highly active antiretroviral therapy (HAART) use were associated with increased risk of diabetes.
Incident hyperglycaemia is common among older adults with or at-risk for HIV infection. HIV-infected individuals with classic diabetes risk factors should be screened for hyperglycaemia regardless of HAART use. OGTTs may be the preferred screening strategy in HIV-infected individuals at high risk for developing hyperglycaemia.
The genetics of lymphoma susceptibility reflect the marked heterogeneity of diseases that comprise this broad phenotype. However, multiple subtypes of lymphoma are observed in some families, suggesting shared pathways of genetic predisposition to these pathologically distinct entities. Using a two-stage GWAS, we tested 530,583 SNPs in 944 cases of lymphoma, including 282 familial cases, and 4,044 public shared controls, followed by genotyping of 50 SNPs in 1,245 cases and 2,596 controls. A novel region on 11q12.1 showed association with combined lymphoma (LYM) subtypes. SNPs in this region included rs12289961 near LPXN, (PLYM = 3.89×10−8, OR = 1.29) and rs948562 (PLYM = 5.85×10−7, OR = 1.29). A SNP in a novel non-HLA region on 6p23 (rs707824, PNHL = 5.72×10−7) was suggestive of an association conferring susceptibility to lymphoma. Four SNPs, all in a previously reported HLA region, 6p21.32, showed genome-wide significant associations with follicular lymphoma. The most significant association with follicular lymphoma was for rs4530903 (PFL = 2.69×10−12, OR = 1.93). Three novel SNPs near the HLA locus, rs9268853, rs2647046, and rs2621416, demonstrated additional variation contributing toward genetic susceptibility to FL associated with this region. Genes implicated by GWAS were also found to be cis-eQTLs in lymphoblastoid cell lines; candidate genes in these regions have been implicated in hematopoiesis and immune function. These results, showing novel susceptibility regions and allelic heterogeneity, point to the existence of pathways of susceptibility to both shared as well as specific subtypes of lymphoid malignancy.
B-cell lymphomas comprise several diseases representing aberrant proliferations of immune cells at various stages of maturation. It might be expected that dissimilar subtypes of lymphoma will have different etiologic and pathogenic mechanisms, reflecting the distinct histologic and clinical characteristics of these diseases. This study aims to define both shared as well as specific genetic risk factors for lymphoma. Utilizing a genome-wide approach, we discovered novel locations in the genome associated with risk for lymphoid malignancies. Common variants in these regions, on chromosome 11q12.1 and 6p23, were each associated with a modest modification of risk for lymphoma. These regions harbor several genes of biological importance in lymphoid maturation and function. We also further characterized the HLA region at 6p21.32, previously associated with lymphoma risk and thought to be important in immune function. Some of the associated SNP markers were specific for one common subtype of lymphoma, e.g. follicular lymphoma. However, others were associated with combined subsets of disease, suggesting that there are both shared and subtype-specific associations between common genetic variants and human lymphoid cancer. Secondary analyses showed that the two novel regions harbor candidates that are biologically relevant and that regulate cell development and hematopoiesis.
The objective of this study was to quantify the direct medical resources used and the corresponding burden of disease in the treatment of patients with schizophrenia. Because low-frequency administration (LFA) of risperidone guarantees adherence during treatment intervals and offers fewer opportunities to discontinue, adherence and persistence were assumed to improve, thereby reducing relapses of major symptoms.
A decision tree model including Markov processes with monthly cycles and a five-year maximum timeframe was constructed. Costs were adapted from the literature and discounted at a 3% annual rate. The population is a demographically homogeneous cohort of patients with schizophrenia, differentiated by initial disease severity (mildly ill, moderately ill, and severely ill). Treatment parameters are estimated using published information for once-daily risperidone standard oral therapy (RIS-SOT) and once-monthly risperidone long-acting injection (RIS-LAI) with LFA therapy characteristics derived from observed study trends. One-year and five-year results are expressed as discounted direct medical costs and mean number of relapses per patient (inpatient, outpatient, total) and are estimated for LFA therapies given at three, six, and nine month intervals.
The one-year results show that LFA therapy every 3 months (LFA-3) ($6,088) is less costly than either RIS-SOT ($10,721) or RIS-LAI ($9,450) with similar trends in the 5-year results. Moreover, the model predicts that LFA-3 vs. RIS-SOT vs. RIS LAI therapy will reduce costly inpatient relapses (0.16 vs. 0.51 vs. 0.41). Extending the interval to six (LFA-6) and nine (LFA-9) months resulted in further reductions in relapse and costs.
Limitations include the fact that LFA therapeutic options are hypothetical and do not yet exist and limited applicability to compare one antipsychotic agent versus another as only risperidone therapy is evaluated. However, study results have quantified the potential health state improvements and potential direct medical cost savings achievable with the development and use of LFA medication delivery technologies.
Objective This article presents a summary of findings from asthma studies focusing on immigration and acculturation-related factors. A study examining associations between these processes, family cohesion and social support networks, and asthma morbidity in a sample of Dominican and Puerto Rican caregivers residing in the mainland U.S., is also described. Methods Latino children with asthma (n = 232), ages 7–16 (49% female) and their caregivers completed interview-based questionnaires on immigration and acculturation-related processes, family characteristics, and asthma morbidity. Results The frequency of ED use due to asthma may be higher for children of caregivers born in Puerto Rico. Acculturative stress levels were higher for Puerto Rican born caregivers residing in the mainland U.S. Conclusion Asthma-related educational and intervention programs for Latino children and families should be tailored to consider the effects that the immigration and acculturation experience can have on asthma management. Specific family-based supports focused on decreasing stress related to the acculturation process, and increasing social and family support around the asthma treatment process may help to reduce asthma morbidity in Latino children.
acculturation; asthma morbidity; immigration
This paper presents the model and results to evaluate the use of teriparatide as a first-line treatment of severe postmenopausal osteoporosis (PMO) and Glucocorticoid-induced osteoporosis (GIOP). The study’s objective was to determine if teriparatide is cost effective against oral bisphosphonates for two large and high risk cohorts.
A computer simulation model was created to model treatment, osteoporosis related fractures, and the remaining life of PMO and GIOP patients. Natural mortality and additional mortality from osteoporosis related fractures were included in the model. Costs for treatment with both teriparatide and oral bisphosphonates were included. Drug efficacy was modeled as a reduction to the relative fracture risk for subsequent osteoporosis related fractures. Patient health utilities associated with age, gender, and osteoporosis related fractures were included in the model. Patient costs and utilities were summarized and incremental cost-effectiveness ratios (ICERs) for teriparatide versus oral bisphosphonates and teriparatide versus no treatment were estimated.
For each of the PMO and GIOP populations, two cohorts differentiated by fracture history were simulated. The first contained patients with both a historical vertebral fracture and an incident vertebral fracture. The second contained patients with only an incident vertebral fracture. The PMO cohorts simulated had an initial Bone Mineral Density (BMD) T-Score of −3.0. The GIOP cohorts simulated had an initial BMD T-Score of −2.5.
The ICERs for teriparatide versus bisphosphonate use for the one and two fracture PMO cohorts were €36,995 per QALY and €19,371 per QALY. The ICERs for teriparatide versus bisphosphonate use for the one and two fracture GIOP cohorts were €20,826 per QALY and €15,155 per QALY, respectively.
The selection of teriparatide versus oral bisphosphonates as a first-line treatment for the high risk PMO and GIOP cohorts evaluated is justified at a cost per QALY threshold of €50,000.
Glucocorticoid-induced osteoporosis; Postmenopausal osteoporosis; Cost-effectiveness; Fractures; Teriparatide; Bisphosphonate
While rhizome formation is intimately associated with perennialism and the derived benefit of sustainability, the introduction of this trait into temperate-zone adapted Sorghum cultivars requires precise knowledge of the genetics conditioning this trait in order to minimize the risk of weediness (e.g., Johnsongrass, S. halepense) while maximizing the productivity of perennial sorghum. As an incremental step towards dissecting the genetics of perennialism, a segregating F4 heterogeneous inbred family derived from a cross between S. bicolor and S. propinquum was phenotyped in both field and greenhouse environments for traits related to over-wintering and rhizome formation. An unseasonably cold winter in 2011 provided high selection pressure, and hence 74.8 % of the population did not survive. This severe selection pressure for cold tolerance allowed the resolution of two previously unidentified over-wintering quantitative trait locus (QTL) and more powerful correlation models than previously reported. Conflicting with previous reports, a maximum of 33 % of over-wintering variation could be explained by above-ground shoot formation from rhizomes; however, every over-wintering plant exhibited rhizome growth. Thus, while rhizome formation is required for over-wintering, other factors also determine survival in this interspecific population. The fine mapping of a previously reported rhizome QTL on sorghum chromosome SBI-01 was conducted by targeting this genomic region with additional simple sequence repeat markers. Fine mapping reduced the 2-LOD rhizome QTL interval from ~59 to ~14.5 Mb, which represents a 75 % reduction in physical distance and a 53 % reduction in the number of putative genes in the locus.
Electronic supplementary material
The online version of this article (doi:10.1007/s11032-012-9778-8) contains supplementary material, which is available to authorized users.
Perennialism; Perenniality; Rhizomes; Sorghum; Sorghum propinquum
Though genome-wide association studies (GWAS) have identified numerous susceptibility loci for common diseases, their use is limited due to the expense of genotyping large cohorts of individuals. One potential solution is to use ‘additional controls’, or genotype data from control individuals deposited in public repositories. While this approach has been used by several groups, the genetically heterogeneous nature of the population of the United States makes this approach potentially problematic. We empirically investigated the utility of this approach in a US-based GWAS. In a small GWAS of pancreatic cancer in New York, we observed clear population structure differences relative to controls from the database of Genotypes and Phenotypes (dbGaP). When we conduct the GWAS using these additional controls, we find large inflation of the test statistic that is properly corrected by using eigenvectors from principal components analysis as covariates. To deal with errors introduced due to different sources, we propose simultaneously genotyping a small number of controls along with cases and then comparing this group to the additional controls. We show that removing SNPs that show differences between these control groups reduces false-positive findings. Thus, through an empirical approach, this report provides practical guidance for using additional controls from publicly available datasets.
Genome-wide association studies; Additional controls; dbGaP; Population stratification; Pancreatic cancer
Signaling via the type 4-melanocortin receptor (MC4R) is an important determinant of body weight in mice and humans, where loss of function mutations lead to significant obesity. Humans with mutations in the MC4R experience an increase in lean mass. However, the simultaneous accrual of fat mass in such individuals may contribute to this effect via mechanical loading. We therefore examined the relationship of fat mass and lean mass in mice lacking the type-4 melanocortin receptor (MC4RKO). We demonstrate that MC4RKO mice display increased lean body mass. Further, this is not dependent on changes in adipose mass, as MC4RKO mice possess more lean body mass than diet-induced obese (DIO) wild type mice with equivalent fat mass. To examine potential sources of the increased lean mass in MC4RKO mice, bone mass and strength were examined in MC4RKO mice. Both parameters increase with age in MC4RKO mice, which likely contributes to increases in lean body mass. We functionally characterized the increased lean mass in MC4RKO mice by examining their capacity for treadmill running. MC4R deficiency results in a decrease in exercise performance. No changes in the ratio of oxidative to glycolytic fibers were seen, however MC4RKO mice demonstrate a significantly reduced heart rate, which may underlie their impaired exercise performance. The reduced exercise capacity we report in the MC4RKO mouse has potential clinical ramifications, as efforts to control body weight in humans with melanocortin deficiency may be ineffective due to poor tolerance for physical activity.
The lifetime prevalence of self-reported asthma among Puerto Ricans is very high, with increased asthma hospitalizations, emergency department visits, and mortality rates. Differences in asthma severity between the mainland and island, however, remain largely unknown.
We sought to characterize differences in asthma severity and control among 4 groups: (1) Island Puerto Ricans, (2) Rhode Island (RI) Puerto Ricans, (3) RI Dominicans, and (4) RI whites.
Eight hundred five children aged 7 to 15 years completed a diagnostic clinic session, including a formal interview, physical examination, spirometry, and allergy testing. Using a visual grid adapted from the Global Initiative for Asthma, asthma specialists practicing in each site determined an asthma severity rating. A corresponding level of asthma control was determined by using a computer algorithm.
Island Puerto Ricans had significantly milder asthma severity compared with RI Puerto Ricans, Dominicans, and whites (P < .001). Island Puerto Ricans were not significantly different from RI whites in asthma control. RI Puerto Ricans showed a trend toward less control compared with island Puerto Ricans (P = .061). RI Dominicans had the lowest rate of controlled asthma. Paradoxically, island Puerto Ricans had more emergency department visits in the past 12 months (P < .001) compared with the 3 RI groups.
Potential explanations for the paradoxic finding of milder asthma in island Puerto Ricans in the face of high health care use are discussed. Difficulties in determining guideline-based composite ratings for severity versus control are explored in the context of disparate groups.
Asthma; severity; control; clinical guidelines; Global Initiative for Asthma; Latino; Puerto Rican; Dominican; Rhode Island; health care use
Many studies have chronicled the “epidemiologic synergy” between human immunodeficiency virus (HIV) and herpes simplex virus type 2 (HSV-2). HIV adversely affects the natural history of HSV-2 and results in more frequent and severe HSV-2 reactivation. Few longitudinal studies, however, have examined whether HSV-2 is associated with increased HIV plasma viral loads or decreased CD4 counts. The authors estimated the effect of HSV-2 seropositivity on HIV RNA viral load and on CD4 count over time among 777 HIV-seropositive US women not receiving suppressive HSV-2 therapy in the HIV Epidemiology Research Study (1993–2000). Linear mixed models were used to assess the effect of HSV-2 on log HIV viral load and CD4 count/mm3 prior to widespread initiation of highly active antiretroviral therapy. Coinfection with HSV-2 was not associated with HIV RNA plasma viral loads during study follow-up. There was a statistically significant association between HSV-2 seropositivity and CD4 count over time, but this difference was small and counterintuitive at an increase of 8 cells/mm3 (95% confidence interval: 2, 14) per year among HSV-2-seropositive women compared with HSV-2-seronegative women. These data do not support a clinically meaningful effect of baseline HSV-2 seropositivity on the trajectories of HIV plasma viral loads or CD4 counts.
CD4 lymphocyte count; herpes simplex; herpesvirus 2, human; HIV; viral load
Predictors of liver fibrosis were evaluated in women using a noninvasive index (FIB-4). HIV RNA levels were associated with increased FIB-4 in the absence of viral hepatitis, alcohol use, or antiretroviral therapy. These data complement evidence suggesting a potential relationship between HIV infection and hepatic fibrosis.
Background. FIB-4 represents a noninvasive, composite index that is a validated measure of hepatic fibrosis, which is an important indicator of liver disease. To date, there are limited data regarding hepatic fibrosis in women.
Methods. FIB-4 was evaluated in a cohort of 1227 women, and associations were evaluated in univariate and multivariate regression models among 4 groups of subjects classified by their human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infection status.
Results. The median FIB-4 scores were 0.60 in HIV-/HCV- women, 0.83 in HIV-/HCV+ women, 0.86 in HIV+/HCV- women, and 1.30 in HIV+/HCV+ women. In the HIV/HCV co-infected group, multivariate analysis showed that CD4+ cell count and albumin level were negatively associated with FIB-4 (P <.0001), whereas antiretroviral therapy (ART) was positively associated with FIB-4 score (P =.0008). For the HIV mono-infected group, multivariate analysis showed that CD4+ cell count (P <.0001) and albumin level (P =.0019) were negatively correlated with FIB-4 score, ART was positively associated with FIB-4 score (P =.0008), and plasma HIV RNA level was marginally associated with FIB-4 score (P =.080). In 72 HIV mono-infected women who were also hepatitis B surface antigen negative, ART naive, and reported no recent alcohol intake, plasma HIV RNA level was associated with increased FIB-4 score (P =.030).
Conclusions. HIV RNA level was associated with increased FIB-4 score in the absence of hepatitis B, hepatitis C, ART, or alcohol use, suggesting a potential relationship between HIV infection and hepatic fibrosis in vivo. A better understanding of the various demographic and virologic variables that contribute to hepatic fibrosis may lead to more effective treatment of HIV infection and its co-morbid conditions.
This study examined the relationship between obesity and asthma symptom perception in 200 youth with asthma. Repeated subjective and objective peak flow measurements were summarized using the Asthma Risk Grid (Klein et al., 2004), resulting in Accurate, Symptom Magnification and Danger Zone scores. Analyses were stratified by age and included ethnicity.
For younger children, obesity was not significantly related to perception scores. For older children, a significant obesity-by-ethnicity interaction for Accurate Symptom Perception scores indicated that obese white children had lower accuracy than white nonobese children, while there was no difference for obese versus nonobese minority children. Obesity was also related to higher Symptom Magnification scores regardless of ethnicity for older children.
These findings suggest that obesity may complicate asthma management by interfering with the ability to accurately perceive symptoms for some patients. More remains to be learned about the role of sociodemographic factors underlying this relationship.
Asthma; Body mass index; Obesity; Symptom perception; Children