PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-11 (11)
 

Clipboard (0)
None

Select a Filter Below

Journals
Year of Publication
Document Types
1.  Follistatin-like Protein 1 and the Ferritin/Erythrocyte Sedimentation Rate Ratio Are Potential Biomarkers for Dysregulated Gene Expression and Macrophage Activation Syndrome in Systemic Juvenile Idiopathic Arthritis 
The Journal of rheumatology  2013;40(7):10.3899/jrheum.121131.
Objective
Follistatin-like protein 1 (FSTL-1) is a secreted glycoprotein overexpressed in certain inflammatory diseases. Our objective was to correlate FSTL-1 levels with gene expression, known biomarkers, and measures of disease activity in systemic juvenile idiopathic arthritis (sJIA), including macrophage activation syndrome (MAS).
Methods
FSTL-1 serum levels were measured by ELISA in 28 patients with sJIA, including 7 patients who developed MAS, and 30 healthy controls. Levels were correlated with erythrocyte sedimentation rate (ESR), ferritin, and soluble interleukin-2 receptor-α (sIL-2Rα). Gene expression based on FSTL-1 levels was analyzed in peripheral blood mononuclear cells (PBMC).
Results
Serum levels of FSTL-1 were elevated at time of presentation of sJIA (mean 200.7 ng/ml) and decreased to normal (mean 133.7 ng/ml) over 24 months (p < 0.01). FSTL-1 levels were markedly elevated during acute MAS (mean 279.8 ng/ml) and decreased to normal following treatment (p < 0.001). FSTL-1 levels correlated with serum markers of inflammation, including sIL-2Rα and ferritin. Ferritin/ESR ratio was superior to ferritin, sIL-2Rα, and FSTL-1 in discriminating MAS from new-onset sJIA. PBMC from patients with FSTL-1 levels > 200 ng/ml showed altered expression of genes related to innate immunity, erythropoiesis, and natural killer cell dysfunction. Two patients with the highest FSTL-1 levels at disease onset (> 300 ng/ml) ultimately developed MAS.
Conclusion
Elevated pretreatment serum FSTL-1 levels in sJIA are associated with dysregulated gene expression suggestive of occult MAS, and may have utility in predicting progression to overt MAS. Ferritin/ESR ratio may be superior to ferritin alone in discriminating overt MAS from new-onset sJIA. (First Release May 15 2013; J Rheumatol 2013;40:1191–9; doi:10.3899/jrheum.121131)
doi:10.3899/jrheum.121131
PMCID: PMC3885333  PMID: 23678162
SYSTEMIC JUVENILE IDIOPATHIC ARTHRITIS; SENSITIVITY; SPECIFICITY; MACROPHAGE ACTIVATION SYNDROME; FOLLISTATIN-LIKE PROTEIN 1; BIOMARKERS
2.  Challenges in creating an opt-in biobank with a registrar-based consent process and a commercial EHR 
Residual clinical samples represent a very appealing source of biomaterial for translational and clinical research. We describe the implementation of an opt-in biobank, with consent being obtained at the time of registration and the decision stored in our electronic health record, Epic. Information on that decision, along with laboratory data, is transferred to an application that signals to biobank staff whether a given sample can be kept for research. Investigators can search for samples using our i2b2 data warehouse. Patient participation has been overwhelmingly positive and much higher than anticipated. Over 86% of patients provided consent and almost 83% requested to be notified of any incidental research findings. In 6 months, we obtained decisions from over 18 000 patients and processed 8000 blood samples for storage in our research biobank. However, commercial electronic health records like Epic lack key functionality required by a registrar-based consent process, although workarounds exist.
doi:10.1136/amiajnl-2012-000960
PMCID: PMC3486732  PMID: 22878682
Biological specimen banks; biorepository; informed consent; electronic health records; medical informatics
3.  Multiple juvenile idiopathic arthritis subtypes demonstrate pro-inflammatory IgG glycosylation 
Arthritis and rheumatism  2012;64(9):3025-3033.
OBJECTIVES
Rheumatoid arthritis is associated with an excess of hypogalactosylated (G0) IgG that is considered relatively pro-inflammatory. Assessment of this association in juvenile idiopathic arthritis (JIA) is complicated by age-dependent IgG glycan variation. We undertook the first large-scale survey of IgG glycans in normal children and in patients with JIA, with a focus on early childhood, the time of peak JIA incidence.
METHODS
IgG glycans from healthy children and DMARD-naïve JIA patients were characterized using high-performance liquid chromatography (HPLC). Pro-inflammatory G0 glycans were quantitated with reference to monogalactosylated (G1) species. Associations were sought between G0/G1 and disease characteristics.
RESULTS
Among healthy children aged 9 months-16 years (n=165), G0/G1 was highly age-dependent, peaking in children <3 years old at 1.19 and declining to a nadir of 0.83 after age 10 years (Spearman ρ=0.60, p<0.0001). In patients with JIA (n=141), G0/G1 was elevated compared with controls (G0/G1 1.32 vs. 1.02, p<0.0001). Corrected for age, G0/G1 was abnormally high in all JIA subtypes (enthesitis-related arthritis not assessed), most strikingly in systemic JIA. Glycosylation aberrancy was comparable in patients with or without ANA and in both early- and late-onset disease, and exhibited at most a weak correlation with inflammatory markers.
CONCLUSIONS
IgG glycosylation is skewed toward pro-inflammatory G0 variants in healthy children, in particular during the first few years of life. This deviation is exaggerated in patients with JIA. The role for IgG glycan variation in immune function in children, including the predilection of JIA for early childhood, remains to be defined.
doi:10.1002/art.34507
PMCID: PMC3429730  PMID: 22549726
4.  Gene Expression Profiles from Peripheral Blood Mononuclear Cells Are Sensitive to Short Processing Delays 
Biopreservation and biobanking  2010;8(3):153-162.
In the analysis of peripheral blood gene expression, timely processing of samples is essential to ensure that measurements reflect in vivo biology, rather than ex vivo sample processing variables. The effect of processing delays on global gene expression patterns in peripheral blood mononuclear cells (PBMCs) was assessed by isolating and stabilizing PBMC-derived RNA from 3 individuals either immediately after phlebotomy or after a 4 h delay. RNA was labeled using NuGEN Ovation labeling and probed using the Affymetrix HG U133 Plus 2.0 GeneChip®. Comparison of gene expression levels (≥2-fold expression change and P < 0.05) identified 307 probe sets representing genes with increased expression and 46 indicating decreased expression after 4 h. These differentially expressed genes include many that are important to inflammatory, immunologic, and cancer pathways. Among others, CCR2, CCR5, TLR10, CD180, and IL-16 have decreased expression, whereas VEGF, IL8, SOCS2, SOCS3, CD69, and CD83 have increased expression after a 4 h processing delay. The trends in expression patterns associated with delayed processing were also apparent in an independent set of 276 arrays of RNA from human PBMC samples with varying processing times. These data indicate that the time between sample acquisition, initiation of processing, and when the RNA is stabilized should be a prime consideration when designing protocols for translational studies involving PBMC gene expression analysis.
doi:10.1089/bio.2010.0009
PMCID: PMC3129811  PMID: 21743826
5.  Genome-wide association analysis of juvenile idiopathic arthritis identifies a new susceptibility locus at chromosomal region 3q13 
Arthritis and rheumatism  2012;64(8):2781-2791.
Objective
We have conducted a GWAS in a Caucasian cohort of juvenile idiopathic arthritis (JIA) patients and have previously published findings limited to autoimmune loci shared with other diseases. The goal of this study was to identify novel JIA predisposing loci using genome-wide approaches.
Methods
The Discovery cohort consisted of Caucasian JIA cases (814) and local controls (658) genotyped on the Affymetrix SNP 6.0 Array along with 2400 out-of-study controls. A replication study consisted of 10 SNPs genotyped in 1744 cases and 7010 controls from the US and Europe.
Results
Analysis within the Discovery cohort provided evidence of associations at 3q13 within C3orf1 and near CD80 (rs4688011, OR=1.37, P=1.88×10−6), and 10q21 near the gene JMJD1C [rs6479891, odds ratio (OR) =1.59, P=6.1×10−8; rs12411988, OR=1.57, P=1.16×10−7 and rs10995450, OR = 1.31, P=6.74×10−5]. Meta-analysis continued to provide evidence for association for these 4 SNPs (rs4688011, P=3.6×10−7, rs6479891, P=4.33×10−5; rs12411988, P=2.71×10−5; and rs10995450, 5.39×10−5;). Gene expression data from 68 JIA cases and 23 local controls showed cis eQTL associations for C3orf1 SNP rs4688011 (P=0.024 or P=0.034, depending on probe set) and the JMJD1C SNPs rs6479891 and rs12411988 (P=0.01 and P=0.008, respectively). A variance component liability model estimated that common SNP variation accounts for ~1/3 of JIA susceptibility.
Conclusions
Genetic association results and correlated gene expression findings provide evidence of association at 3q13 and 10q21 for JIA and offer novel genes as plausible candidates in disease pathology.
doi:10.1002/art.34429
PMCID: PMC3366043  PMID: 22354554
6.  Gene Expression Profiles from Peripheral Blood Mononuclear Cells Are Sensitive to Short Processing Delays 
Biopreservation and Biobanking  2010;8(3):153-162.
In the analysis of peripheral blood gene expression, timely processing of samples is essential to ensure that measurements reflect in vivo biology, rather than ex vivo sample processing variables. The effect of processing delays on global gene expression patterns in peripheral blood mononuclear cells (PBMCs) was assessed by isolating and stabilizing PBMC-derived RNA from 3 individuals either immediately after phlebotomy or after a 4 h delay. RNA was labeled using NuGEN Ovation labeling and probed using the Affymetrix HG U133 Plus 2.0 GeneChip®. Comparison of gene expression levels (≥2-fold expression change and P < 0.05) identified 307 probe sets representing genes with increased expression and 46 indicating decreased expression after 4 h. These differentially expressed genes include many that are important to inflammatory, immunologic, and cancer pathways. Among others, CCR2, CCR5, TLR10, CD180, and IL-16 have decreased expression, whereas VEGF, IL8, SOCS2, SOCS3, CD69, and CD83 have increased expression after a 4 h processing delay. The trends in expression patterns associated with delayed processing were also apparent in an independent set of 276 arrays of RNA from human PBMC samples with varying processing times. These data indicate that the time between sample acquisition, initiation of processing, and when the RNA is stabilized should be a prime consideration when designing protocols for translational studies involving PBMC gene expression analysis.
doi:10.1089/bio.2010.0009
PMCID: PMC3129811  PMID: 21743826
7.  Biologic similarities based on age at onset in oligoarticular and polyarticular subtypes of juvenile idiopathic arthritis 
Arthritis and rheumatism  2010;62(11):3249-3258.
Objective
To explore biologic correlates to age at onset in patients with juvenile idiopathic arthritis (JIA) using peripheral blood mononuclear cell (PBMC) gene expression analysis.
Methods
PBMCs were isolated from 56 healthy controls and 104 patients with recent-onset JIA (39 with persistent oligoarticular JIA, 45 with rheumatoid factor–negative polyarticular JIA, and 20 with systemic JIA). RNA was amplified and labeled using NuGEN Ovation, and gene expression was assessed with Affymetrix HG-U133 Plus 2.0 GeneChips.
Results
A total of 832 probe sets revealed gene expression differences (false discovery rate 5%) in PBMCs from children with oligoarticular JIA whose disease began before age 6 years (early-onset disease) compared with those whose disease began at or after age 6 years (late-onset disease). In patients with early-onset disease, there was greater expression of genes related to B cells and less expression of genes related to cells of the myeloid lineage. Support vector machine analyses identified samples from patients with early- or late-onset oligoarticular JIA (with 97% accuracy) or from patients with early- or late-onset polyarticular JIA (with 89% accuracy), but not from patients with systemic JIA or healthy controls. Principal components analysis showed that age at onset was the major classifier of samples from patients with oligoarticular JIA and patients with polyarticular JIA.
Conclusion
PBMC gene expression analysis reveals biologic differences between patients with early-and late-onset JIA, independent of classification based on the number of joints involved. These data suggest that age at onset may be an important parameter to consider in JIA classification. Furthermore, pathologic mechanisms may vary with age at onset, and understanding these processes may lead to improved treatment of JIA.
doi:10.1002/art.27657
PMCID: PMC3018072  PMID: 20662067
8.  Gene Expression Signatures in Polyarticular Juvenile Idiopathic Arthritis Demonstrate Disease Heterogeneity and Offer a Molecular Classification of Disease Subsets 
Arthritis and rheumatism  2009;60(7):2113-2123.
Objective
Microarray analysis was used to determine whether children with recent onset polyarticular juvenile idiopathic arthritis (JIA) exhibit biologically or clinically informative gene expression signatures in peripheral blood mononuclear cells (PBMC).
Methods
Peripheral blood samples were obtained from 59 healthy children and 61 children with polyarticular JIA prior to treatment with second-line medications, such as methotrexate or biological agents. RNA was extracted from Ficoll-isolated mononuclear cells, fluorescently labeled and hybridized to Affymetrix U133 Plus 2.0 GeneChips. Data were analyzed using ANOVA at a 5% false discovery rate threshold after Robust Multi-Array Average pre-processing and Distance Weighted Discrimination normalization.
Results
Initial analysis revealed 873 probe sets for genes that were differentially expressed between polyarticular JIA and controls. Hierarchical clustering of these probe sets distinguished three subgroups within polyarticular JIA. Prototypical subjects within each subgroup were identified and used to define subgroup-specific gene expression signatures. One of these signatures was associated with monocyte markers, another with transforming growth factor β-inducible genes, and a third with immediate-early genes. Correlation of gene expression signatures with clinical and biological features of JIA subgroups suggests relevance to aspects of disease activity and supports the division of polyarticular JIA into distinct subsets.
Conclusions
PBMC gene expression signatures in recent onset polyarticular JIA reflect discrete disease processes and offer a molecular classification of disease.
doi:10.1002/art.24534
PMCID: PMC2741130  PMID: 19565504
9.  Immature cell populations and an erythropoiesis gene-expression signature in systemic juvenile idiopathic arthritis: implications for pathogenesis 
Arthritis Research & Therapy  2010;12(3):R123.
Introduction
Previous observations suggest that active systemic juvenile idiopathic arthritis (sJIA) is associated with a prominent erythropoiesis gene-expression signature. The aim of this study was to determine the association of this signature with peripheral blood mononuclear cell (PBMC) subpopulations and its specificity for sJIA as compared with related conditions.
Methods
The 199 patients with JIA (23 sJIA and 176 non-sJIA) and 38 controls were studied. PBMCs were isolated and analyzed for multiple surface antigens with flow cytometry and for gene-expression profiles. The proportions of different PBMC subpopulations were compared among sJIA, non-sJIA patients, and controls and subsequently correlated with the strength of the erythropoiesis signature. Additional gene-expression data from patients with familial hemophagocytic lymphohistiocytosis (FHLH) and from a published sJIA cohort were analyzed to determine whether the erythropoiesis signature was present.
Results
Patients with sJIA had significantly increased proportions of immature cell populations, including CD34+ cells, correlating highly with the strength of the erythropoiesis signature. The erythropoiesis signature strongly overlapped with the gene-expression pattern in purified immature erythroid precursors. The expansion of immature cells was most prominently seen in patients with sJIA and anemia, even in the absence of reticulocytosis. Patients with non-sJIA and anemia did not exhibit the erythropoiesis signature. The erythropoiesis signature was found to be prominent in patients with FHLH and in a published cohort of patients with active sJIA, but not in patients with inactive sJIA.
Conclusions
An erythropoiesis signature in active sJIA is associated with the expansion of CD34+ cells, also is seen in some patients with FHLH and infection, and may be an indicator of ineffective erythropoiesis and hemophagocytosis due to hypercytokinemia.
doi:10.1186/ar3061
PMCID: PMC2911917  PMID: 20576155
10.  Growth Phase Influences Complement Resistance of Bordetella pertussis  
Infection and Immunity  2002;70(1):403-406.
The BrkA protein of Bordetella pertussis inhibits killing by the antibody-dependent classical pathway of complement; however, susceptibility to complement can be highly variable. Log-phase bacteria grown in Stainer-Scholte (SS) broth plated on Bordet-Gengou (BG) agar were about 500 times more sensitive to killing by complement than stationary-phase SS-BG cultures. While always more susceptible to complement than the wild-type strain, a BrkA mutant displayed a similar growth phase variation in susceptibility to complement. Growth phase susceptibility to complement was also observed for a mutant constitutive for Bvg activation of BrkA, suggesting that modulation of virulence factor expression was not responsible for sensitivity to complement. Susceptibility was not due to differential antigenic expression, since serum adsorbed with complement-resistant, stationary-phase SS-BG cultures lacked bactericidal activity against B. pertussis harvested at all times during the growth cycle. These results suggest that log-phase susceptibility to complement is not due to variable expression of BrkA or antigenic differences and may be an inherent property of rapidly growing cultures. Implications for vaccine development are discussed.
doi:10.1128/IAI.70.1.403-406.2002
PMCID: PMC127634  PMID: 11748208
11.  BrkA Protein of Bordetella pertussis Inhibits the Classical Pathway of Complement after C1 Deposition 
Infection and Immunity  2001;69(5):3067-3072.
Bordetella pertussis produces a 73-kDa protein, BrkA (Bordetella resistance to killing), which inhibits the bactericidal activity of complement. In this study we characterized the step in the complement cascade where BrkA acts, using three strains: a wild-type strain, a strain containing an insertional disruption of brkA, and a strain containing two copies of the brkA locus. Following incubation with 10% human serum, killing was greatest for the BrkA mutant, followed by that for the wild-type strain, while the strain with two copies of brkA was the most resistant. Complement activation was monitored by enzyme-linked immunosorbent assay (ELISA) or Western blotting. ELISAs for SC5b-9, the soluble membrane attack complex, showed that production of SC5b-9 was greatest with the brkA mutant, less with the wild type, and least with the strain containing two copies of brkA. Deposition of complement proteins on the bacteria was monitored by Western blotting. A decrease in deposition on the bacteria of C4, C3, and C9 corresponded with decreased complement sensitivity. Deposition of C1, however, was not affected by the presence of BrkA. These studies show that BrkA inhibits the classical pathway of complement activation and prevents accumulation of deposited C4.
doi:10.1128/IAI.69.5.3067-3072.2001
PMCID: PMC98261  PMID: 11292725

Results 1-11 (11)