Systemic lupus erythematosus (SLE) is a systemic autoimmune disease that predominantly affects women. Despite Klinefelter's syndrome (47,XXY) and SLE coexisting in isolated cases, no association has been established with SLE or any other autoimmune disease. Methods: Sex chromosome genotyping was performed in 981 SLE patients (213 were men). A first group of 843 SLE patients from 378 multiplex families and a second group of 138 men with non-familial SLE were evaluated. Fluorescent in situ hybridization (FISH) and karyotyping in transformed B cell lines enumerated chromosomes for selected cases.
Of 213 men with SLE, five had Klinefelter's syndrome (or 1 in 43). Four of them were heterozygous at X markers. FISH and karyotyping confirmed Klinefelter’s syndrome in the fifth. An overall rate of 235 47,XXY per 10,000 male SLE patients (95%CI: 77 to 539) was found, a dramatic increase over the known prevalence of Klinefelter's syndrome in an unselected population (17 per 10,000 live male births). Asking men with SLE about fertility was highly sensitive (100%) for Klinefelter’s syndrome. All 768 SLE women were heterozygous at X.
47,XXY Klinefelter's syndrome, often subclinical, is increased in men with SLE by ~14-fold, compared to its prevalence in men without SLE. Diagnostic vigilance for 47,XXY males in SLE is warranted. These data are the first to associate Klinefelter's syndrome with an autoimmune disease found predominantly in women. The risk of SLE in Klinefelter's syndrome is predicted to be similar to the risk in normal 46,XX women and ~14-fold higher than in 46,XY men, consistent with SLE susceptibility being partly explained by a X chromosome gene dose effect.
Genetic complete deficiency of the early complement components such as C1, C2 and C4 commonly results in a monogenetic form of systemic lupus erythematosus (SLE). However, previous studies have examined groups of complete complement deficient subjects for SLE, while a familial SLE cohort has not been studied for deficiencies of complement. Thus, we undertook the present study to determine the frequency of hereditary complete complement deficiencies among families with two or more SLE patients. All SLE patients from 544 such families had CH50 determined. Medical records were examined for past CH50 values. There were 66 individuals in whom all available CH50 values were zero. All but four of these had an SLE-affected relative with a non-zero CH50; thus, these families did not have monogenic complement deficient related SLE. The four remaining SLE-affected subjects were in fact two sets of siblings in which 3 of the 4 SLE patients had onset of disease at <18 years of age. Both patients in one of these families had been determined to have C4 deficiency, while the other family had no clinical diagnosis of complement deficiency. In this second family, one of the SLE patients had had normal C4 and C3 values, indicating that either C1q or C2 deficiency was possible. Thus, only 2 of 544 SLE families had definite or possible complement deficiency; however, 1 of 7 families in which all SLE patients had pediatric onset and 2 of 85 families with at least 1 pediatric-onset SLE patent had complete complement deficiency. SLE is found commonly among families with hereditary complement deficiency but the reverse is not true. Complete complement deficiency is rare among families with two or more SLE patients, but is concentrated among families with onset of SLE prior to age 18.
Autoimmune thyroid disease is common in systemic lupus erythematosus (SLE). About 20% of patients with SLE have secondary Sjögren's syndrome.
Families with more than one patient with SLE were identified. All patients met the revised classification criteria, although SLE‐unaffected relatives were confirmed not to satisfy these criteria. Diagnosis of autoimmune thyroid disease and Sjögren's syndrome was made on the basis of a review of medical records, interview and questionnaire administered to patients with SLE, and by a questionnaire administered to SLE‐unaffected subjects.
Of a total of 1138 patients with SLE, 169 had a diagnosis of Sjögren's syndrome. Of these 50 (29.6%) patients also had autoimmune thyroid disease. Of the 939 patients with SLE with no diagnosis of Sjögren's syndrome, 119 (12.7%) had autoimmune thyroid disease (χ2 = 20.1, p = 0.000009). There was no association of a diagnosis of hypertension with secondary Sjögren's syndrome (42% vss 47%). Among 2291 SLE‐unaffected relatives, 44 had diagnosed primary Sjögren's syndrome and 16 (36.3%) of these also had autoimmune thyroid disease. 265 of 2247 (11.8%) subjects had autoimmune thyroid disease but no Sjögren's syndrome (χ2 = 24.2, p<0.001).
Autoimmune thyroid disease is found in excess among patients with SLE with a diagnosis of secondary Sjögren's syndrome, as well as among their SLE‐unaffected relatives with a diagnosis of primary Sjögren's syndrome.
MRL/1 and BXSB male mice have a systemic lupus erythematosus (SLE)-like disease similar to but more acute than that occurring in NZB X W mice. The common elements of lymphoid hyperplasia, B-cell hyperactivity, autoantibodies, circulating immune complex (IC), complement consumption, IC glomerulonephritis with gp70 deposition, and thymic atrophy were found in all three kinds of SLE mice. On the basis of these common elements, SLE seen in these mice can be considered a single disease in the same sense that human SLE is one disease. The differences in the SLE expressed in the different mice are no greater than those found in an unselected series of humans with SLE. However, the significant quantitative and qualitative variations in abnormal immunologic expression suggest that different constellations of factors, genetic and/or pathophysiologic, may operate in the three murine strains and that each constellation is capable of leading, via its particular abnormal immunologic consequences, to the activation of common immunopathologic effector mechanisms that cause quite similar SLE-like syndromes. From an experimental point of view, the availability of several inbred murine strains of commonplace histocompatibility types that express an SLE-like syndrome makes possible innumerable manipulations which should help to elucidate the nature and cause(s) of this disorder.
The hepatic involvement of 57 patients with systemic lupus erythematosus (SLE) was studied with special reference to liver membrane autoantibody (LMA). Liver abnormalities were found predominantly in patients with active SLE (27/48 (56%) in active SLE v 3/20 (15%) in inactive SLE). They were, however, rather mild or moderate and tended to disappear as the disease activity of SLE decreased. In this respect the liver abnormalities observed in this study differed from those in patients with lupoid hepatitis. The incidence of LMA in active SLE (8/11 (73%] was significantly greater than that in inactive SLE (4/12 (33%)). The mean LMA index value in active SLE was 8.3, which was also greater than the 2.9 in inactive SLE. Furthermore, in active SLE the mean LMA titre was significantly higher in patients with liver abnormalities than in those without. These results suggest that LMA may be associated with the activity of SLE and may be one of the factors which cause transient liver abnormalities.
Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by the production of autoantibodies to a wide range of self-antigens. Recent genome screens have implicated numerous chromosomal regions as potential SLE susceptibility loci. Among these, the 1q41 locus is of particular interest, because evidence for linkage has been found in several independent SLE family collections. Additionally, the 1q41 locus appears to be syntenic with a susceptibility interval identified in the NZM2410 mouse model for SLE. Here, we report the results of genotyping of 11 microsatellite markers within the 1q41 region in 210 SLE sibpair and 122 SLE trio families. These data confirm the modest evidence for linkage at 1q41 in our family collection (LOD = 1.21 at marker D1S2616). Evidence for significant linkage disequilibrium in this interval was also found. Multiple markers in the region exhibit transmission disequilibrium, with the peak single marker multiallelic linkage disequilibrium noted at D1S490 (pedigree disequilibrium test [PDT] global P value = 0.0091). Two- and three-marker haplotypes from the 1q41 region similarly showed strong transmission distortion in the collection of 332 SLE families. The finding of linkage together with significant transmission disequilibrium provides strong evidence for a susceptibility locus at 1q41 in human SLE.
1q41; autoimmunity; linkage; systemic lupus erythematosus; transmission disequilibrium
Objective: To examine the contribution of genetic and environmental factors to disease occurrence in 26 families with two or more members affected with systemic lupus erythematosus (SLE).
Methods: Genetic and environmental factors were examined by HLA-A, B, C/DR typing and by determining the presence of lymphocytotoxic antibodies (LCA) in patients and their consanguineous and non-consanguineous relatives.
Results: No association between SLE and HLA-A, B, C antigens was found. There was, however, a significant association with HLA-DR2 in white subjects with SLE. The most striking finding was that HLA sharing was increased among the affected members, suggesting genetic similarities. Seven of 14 sib pairs (50%) who had concordant SLE were HLA identical as opposed to an expected 25%. Another interesting finding was that 15/18 (83%) patients with SLE and 11/22 (50%) consanguineous relatives had LCA, while 1/9 (11%) spouses, and 2/42 (5%) healthy controls had these antibodies.
Conclusion: Genetic factors have a role in the development and expression of SLE. Environmental factors may trigger the disease in genetically susceptible hosts.
Women with systemic lupus erythematosus (SLE) have premature and accelerated atherosclerosis. Although percutaneous coronary intervention (PCI) is utilized frequently to treat coronary artery disease (CAD) in SLE, little is known regarding PCI outcomes immediately post-PCI and after discharge.
Methods and Results
Baseline demographic, procedure-related and adverse outcome data on consecutive patients undergoing PCI during 5 recruitment “waves” of the National Heart, Lung, and Blood Institute Dynamic Registry across 23 clinical centers were collected. SLE patients (n= 28) were compared to nonSLE patients (n=3385). SLE patients were younger and more often female in comparison to nonSLE patients undergoing PCI. SLE patients were less likely than nonSLE patients to have hyperlipidemia, but had a similar prevalence of hypertension, diabetes mellitus, and tobacco use. The prevalence of multi-vessel disease was similar between groups. Initial intervention success (by angiographic definition) was not significantly different between groups. At one year, SLE patients were more likely to suffer a myocardial infarction (MI) (15.6% vs. 4.8%, p=0.01), and more often required repeat PCI (31.3% vs. 11.8%, p=0.009) than nonSLE patients, even following adjustment for important covariates.
SLE patients had significantly worse CV outcomes at one year than nonSLE patients. Even considering the small number of SLE patients, these differences were striking. Further study is warranted to explore other factors potentially accounting for this disparity, including SLE disease activity and duration, presence of hypercoagulable state, and immunosuppressive therapy.
angioplasty; catheterization; restenosis; revascularization; systemic lupus erythematosus
Systemic lupus erythematosus (SLE) is a multifactorial disorder characterized by the presence of autoantibodies. We and others have implicated free radical mediated peroxidative damage in the pathogenesis of SLE. Since harmful free radical products are formed during this oxidative process, including 4-hydroxy 2-nonenol (4-HNE) and malondialdehyde (MDA), we hypothesized that specific HNE-protein adducts would be present in SLE red blood cell (RBC) membranes. Catalase is located on chromosome 11p13 where linkage analysis has revealed a marker in the same region of the genome among families with thrombocytopenia, a clinical manifestation associated with severe lupus in SLE affected pedigrees. Moreover, SLE afflicts African-Americans three times more frequently than their European-American counterparts. Hence we investigated the effects of a genetic polymorphism of catalase on risk and severity of SLE in 48 pedigrees with African American ancestry.
Tryptic digestion followed by matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) analysis was used to identify the protein modified by HNE, following Coomassie staining to visualize the bands on the acrylamide gels. Genotyping analysis for the C → T, -262 bp polymorphism in the promoter region of catalase was performed by PCR-RFLP and direct PCR-sequencing. We used a "pedigree disequilibrium test" for the family based association analysis, implemented in the PDT program to analyze the genotyping results.
We found two proteins to be HNE-modified, migrating around 80 and 50 kD respectively. Tryptic digestion followed by matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) analysis of the Coomassie stained 80 kD band revealed that the target of HNE modification was catalase, a protein shown to associate with RBC membrane proteins. All the test statistics carried out on the genotyping analysis for the C → T, -262 bp polymorphism in the promoter region of catalase were non-significant (p > 0.05) in our data, which suggested that this SNP is not associated with SLE.
Our results indicate that catalase is one of the proteins modified due to oxidative stress. However, catalase may not be a susceptibility gene for SLE. Nonetheless, catalase is oxidatively modified among SLE patients. This suggests a possible role between oxidative modification of catalase and its affects on enzymatic activity in SLE. An oxidatively modified catalase could be one of the reasons for lower enzymatic activity among SLE subjects, which in turn could favor the accumulation of deleterious hydrogen peroxide. Furthermore, HNE-products are potential neoantigens and could be involved in the pathogenesis of SLE. Decrease in catalase activity could affect the oxidant-antioxidant balance. Chronic disturbance of this balance in patients with SLE may work favorably for the premature onset of atherogenesis with severe vascular effect.
Systemic lupus erythematosus (SLE) is a sexually dimorphic autoimmune disease which is more common in women, but affected men often experience a more severe disease. The genetic basis of sexual dimorphism in SLE is not clearly defined. A study was undertaken to examine sex-specific genetic effects among SLE susceptibility loci.
A total of 18 autosomal genetic susceptibility loci for SLE were genotyped in a large set of patients with SLE and controls of European descent, consisting of 5932 female and 1495 male samples. Sex-specific genetic association analyses were performed. The sex–gene interaction was further validated using parametric and nonparametric methods. Aggregate differences in sex-specific genetic risk were examined by calculating a cumulative genetic risk score for SLE in each individual and comparing the average genetic risk between male and female patients.
A significantly higher cumulative genetic risk for SLE was observed in men than in women. (P = 4.52×10−8) A significant sex–gene interaction was seen primarily in the human leucocyte antigen (HLA) region but also in IRF5, whereby men with SLE possess a significantly higher frequency of risk alleles than women. The genetic effect observed in KIAA1542 is specific to women with SLE and does not seem to have a role in men.
The data indicate that men require a higher cumulative genetic load than women to develop SLE. These observations suggest that sex bias in autoimmunity could be influenced by autosomal genetic susceptibility loci.
Autoantibodies to ribosomal P are found in 15–30% of systemic lupus erythematosus (SLE) patients and are highly specific for SLE. The goal of this study is to assess the temporal association of anti-ribosomal P (anti-P) responses with SLE disease onset, as well as to characterize the humoral ribosomal P (ribo P) epitopes targeted in early, pre-diagnostic SLE samples. Patients with stored serial serum samples available prior to SLE diagnosis were identified from a military cohort. Each sample was tested for antibodies against ribo P utilizing standard C-terminus ribo P ELISAs and a solid phase, bead-based assay with affinity-purified ribo P proteins. In this study, antibodies to ribo P were more common in African American SLE patients (p= 0.026), and anti-P positive patients comprised a group with more measured autoantibody specificities than did other SLE patients (3.5 vs. 2.2, p<0.05). Antibodies against ribo P were present on average 1.7 years before SLE diagnosis and were detected an average of 1.08 years earlier in pre-diagnostic SLE samples using affinity-purified whole protein rather than C- terminal peptide alone (p=0.0019). Furthermore, 61% of anti-P positive patients initially had antibodies to aa 99–113, a known ribosomal P0 antigenic target, at a time point when no antibodies to the clinically used C-terminus were detected. Our findings provide evidence that antibodies against ribosomal P frequently develop before clinical SLE diagnosis and are more broadly reactive than previously thought by targeting regions outside of the C-terminus.
lupus; antibodies; autoimmunity; ribosomal P; epitope
A high prevalence of autoimmune disease (AD) has been documented in relatives of adult patients with systemic lupus erythematosus (SLE). However, data on familial inheritance patterns in pediatric SLE patients is scarce.
The charts of 69 patients with pediatric-onset SLE were reviewed retrospectively. The primary aim was to describe the prevalence and types of AD in relatives of children with SLE. The secondary aims were: 1) to compare severity of SLE in children with and without relatives affected by AD, and 2) to evaluate the impact of baseline demographics on severity of SLE in subjects. At diagnosis, 42% of subjects had one or more first, second, or third degree relative(s) with AD; and 32% of subjects had one or more first degree relative(s) with AD. The most common diseases in relatives of children with SLE were SLE (21%) and thyroid disease (15%). Subjects with no family history of AD were more likely to have severe SLE. SLE severity in subjects did not differ by gender. Children presenting with SLE at an earlier age were found to have more severe disease.
This study demonstrated a high prevalence of AD in families of children with SLE, although a family history of AD did not correlate with more severe SLE in subjects. Future larger studies are necessary to elucidate patterns of familial inheritance and baseline patient characteristics that may affect severity of disease in pediatric SLE.
Pediatric systemic lupus erythematosus; Severity; Inheritance patterns
Systemic lupus erythematosus (SLE) is a multi-systemic autoimmune
disease leading to immunological aberrations and excessive multiple autoantibody
production. The aim of this study was to investigate the prevalence of
multiple autoantibodies in SLE patients utilizing the multiplex system method.
We analyzed the presence of elevated titers of anti-Ro, anti-La, anti-RNP,
anti-Sm, anti-Jo1, anti-centromere, anti-Scl-70, anti-histone, and anti-dsDNA
antibodies in 199 serum samples (113 SLE patients, 86 healthy donors). We
compared the type, level and number of autoantibodies and the correlation
the autoantibody profile and disease severity utilizing the SLEDAI score.
Elevated titers of at least one autoantibody were detected in 48% of 42 SLE
patients. Elevated titers of anti-Ro antibodies were most commonly detected. The
distribution of specific autoantibodies was: anti-Ro- 23.8%, anti-dsDNA- 19%,
anti-histone- 19%, anti-RNP- 14.2%, anti-La antibodies- 11.9%, anti-Sm- 7.1%,
anti-Scl 70-4.7%, and anti-centromere- 2.4%. Utilizing ROC analysis, the sensitivity
and specificity of anti-DNA antibodies at a cutoff value of 34 IU/ml were 87.1% and
79.4% respectively. Elevated titers of anti-Jo1 antibody were not detected. There
was a correlation with the titer of anti-Ro antibodies and disease activity by the
SLEDAI score. Seven patients harbored one autoantibody only, 15 patients
harbored 2-3 autoantibodies, 3 patients harbored 4-5 autoantibodies, and one
patient harbored 6 autoantibodies. A correlation between the number of
autoantibodies per patient and disease severity was found. One patient with
a multitude of
autoantibodies had severe lupus and a myriad of clinical manifestations.
In conclusion, the multiplex system is specific and sensitive, provides
an autoantibody profile in a single test, and may be useful as a diagnostic
test for SLE. Elevated anti-Ro antibodies are associated with
severe disease. An autoantibody load may be indicative of more severe disease.
Systemic lupus erythematosus (SLE) is a complex autoimmune disease involving critical genetic and environmental risk factors. SLE is a relatively common disease among African American women, affecting as many as one in 250. A collection of more than 250 African American and European American pedigrees multiplex for SLE have been collected in Oklahoma over the past decade for the purpose of identifying the genetic risk factors involved in the pathogenesis of SLE. A genome scan has been performed, and interestingly, the linkage results usually dominate in families from one or the other of these ethnicities. For example, the linkage effect at 1q21-22 near FcgammaRIIA is much stronger in the African American pedigrees than in the European American pedigrees. On the other hand, a gene near the top of chromosome4 (at 4p l6-15) contributes to SLE in the European American pedigrees, but not in the African American pedigrees. The racially-specific results lead to the tentative conclusion of genetic differences associated with SLE in African Americans and European Americans. The identification of the genes responsible for the observed linkage effects will provide fundamental knowledge concerning SLE and may even provide new targets for therapy and strategies to defeat this enigmatic and difficult disease.
The present study was designed to test the possibility that T cell receptor genes are associated/linked to those involved in systemic lupus erythematosus (SLE). Genomic DNA was isolated from 31 unrelated Caucasian SLE patients, 34 unrelated Caucasian normals, 5 multiplex American Caucasian SLE families, 9 multiplex Mexican SLE families, and 13 unrelated Mexican normals. The DNA was digested with Pst I, electrophoresed, and transferred to membranes by the Southern blot method. The blots were probed with a cDNA probe for the alpha chain of the T cell receptor. 13 polymorphic RFLP patterns were recognized. 1.3- and 3.0-kb band pairs were observed in 15 of 31 of American Caucasian patients and 4 of 34 American Caucasian controls (chi square, 8.81; P less than 0.002; relative risk, 7); there was no association of any RFLP pattern with Mexican SLE. The cDNA probe was cut with Rsa I, EcoR I, and Ava II into fragments corresponding to the V, J, C, and 3'UT regions. Only the fragment corresponding to the constant region reacted with the 1.3/3.0-kb band pair. These observations suggest that a genetic marker of the constant region of the alpha chain of the T cell receptor is associated with genes involved in SLE.
Hysterectomy is one of the most common surgical procedures performed in United States, and currently, one in three women in United States has had a hysterectomy by the age of 60 years. Systemic lupus erythematosus (SLE) is a common autoimmune disease and especially targets women of childbearing age at least 10 times higher than men, which reflects the major role of female sex hormones. In this retrospective study, we evaluate the potential effects of previous hysterectomy in our lupus cohort.Data collected fromstudy subject questionnaires were obtained fromthe Lupus Family Registry and Repository (LFRR) at the OklahomaMedical Research Foundation. Hysterectomy data were available from 3389 subjects. SLE patients with a positive history of hysterectomy have been selected and compared with matched lupus patients with a negative history of hysterectomy and healthy controls. Association analyses were performed, and the P values and adjusted odds ratios (ORs) were calculated. SLE patients with a negative history of hysterectomy more likely had kidney nephritis or positive anti-dsDNA than age-matched SLE patients with a history of hysterectomy before disease onset. This effect was independent of ethnicity with an OR of 6.66 (95% CI = 3.09–14.38, P = 1.00 × 10−8) in European patients and 2.74 (95% CI = 1.43–5.25, P = 0.001) in African-Americans. SLE patients with a positive history of hysterectomy before disease onset also had a later age of disease onset (P = 0.0001) after adjustment for age and race. Our findings support the notion that the influence of female sex hormones in SLE and various clinical findings are tremendous and that surgical menopause such as this could significantly affect the outcome of disease and clinical manifestations
Purpose. This study evaluates high-throughput autoantibody screening and determines associated systemic lupus erythematosus (SLE) clinical features in a large lupus cohort. Methods. Clinical and demographic information, along with serum samples, were obtained from each SLE study participant after appropriate informed consent. Serum samples were screened for 10 distinct SLE autoantibody specificities and examined for association with SLE ACR criteria and subcriteria using conditional logistic regression analysis. Results. In European-American SLE patients, autoantibodies against 52 kD Ro and RNP 68 are independently enriched in patients with lymphopenia, anti-La, and anti-ribosomal P are increased in patients with malar rash, and anti-dsDNA and anti-Sm are enriched in patients with proteinuria. In African-American SLE patients, cellular casts associate with autoantibodies against dsDNA, Sm, and Sm/nRNP. Conclusion. Using a high-throughput, bead-based method of autoantibody detection, anti-dsDNA is significantly enriched in patienets with SLE ACR renal criteria as has been previously described. However, lymphopenia is associated with several distinct autoantibody specificities. These findings offer meaningful information to allow clinicians and clinical investigators to understand which autoantibodies correlate with select SLE clinical manifestations across common racial groups using this novel methodology which is expanding in clinical use.
Systemic lupus erythematosus (SLE) is a highly heterogeneous disorder, characterized by differences in autoantibody profile, serum cytokines, and clinical manifestations. SLE-associated autoantibodies and high serum interferon alpha (IFN-α) are important heritable phenotypes in SLE which are correlated with each other, and play a role in disease pathogenesis. These two heritable risk factors are shared between ancestral backgrounds. The aim of the study was to detect genetic factors associated with autoantibody profiles and serum IFN-α in SLE.
We undertook a case-case genome-wide association study of SLE patients stratified by ancestry and extremes of phenotype in serology and serum IFN-α. Single nucleotide polymorphisms (SNPs) in seven loci were selected for follow-up in a large independent cohort of 538 SLE patients and 522 controls using a multi-step screening approach based on novel metrics and expert database review. The seven loci were: leucine-rich repeat containing 20 (LRRC20); protein phosphatase 1 H (PPM1H); lysophosphatidic acid receptor 1 (LPAR1); ankyrin repeat and sterile alpha motif domain 1A (ANKS1A); protein tyrosine phosphatase, receptor type M (PTPRM); ephrin A5 (EFNA5); and V-set and immunoglobulin domain containing 2 (VSIG2).
SNPs in the LRRC20, PPM1H, LPAR1, ANKS1A, and VSIG2 loci each demonstrated strong association with a particular serologic profile (all odds ratios > 2.2 and P < 3.5 × 10-4). Each of these serologic profiles was associated with increased serum IFN-α. SNPs in both PTPRM and LRRC20 were associated with increased serum IFN-α independent of serologic profile (P = 2.2 × 10-6 and P = 2.6 × 10-3 respectively). None of the SNPs were strongly associated with SLE in case-control analysis, suggesting that the major impact of these variants will be upon subphenotypes in SLE.
This study demonstrates the power of using serologic and cytokine subphenotypes to elucidate genetic factors involved in complex autoimmune disease. The distinct associations observed emphasize the heterogeneity of molecular pathogenesis in SLE, and the need for stratification by subphenotypes in genetic studies. We hypothesize that these genetic variants play a role in disease manifestations and severity in SLE.
High serum interferon α (IFNα) activity is a heritable risk factor for systemic lupus erythematosus (SLE). Auto-antibodies found in SLE form immune complexes which can stimulate IFNα production by activating endosomal Toll-like receptors and interferon regulatory factors (IRFs), including IRF5. Genetic variation in IRF5 is associated with SLE susceptibility; however, it is unclear how IRF5 functional genetic elements contribute to human disease.
1034 patients with SLE and 989 controls of European ancestry, 555 patients with SLE and 679 controls of African–American ancestry, and 73 patients with SLE of South African ancestry were genotyped at IRF5 polymorphisms, which define major haplotypes. Serum IFNα activity was measured using a functional assay.
In European ancestry subjects, anti-double-stranded DNA (dsDNA) and anti-Ro antibodies were each associated with different haplotypes characterised by a different combination of functional genetic elements (OR > 2.56, p >003C; 1.9×10−14 for both). These IRF5 haplotype-auto-antibody associations strongly predicted higher serum IFNα in patients with SLE and explained > 70% of the genetic risk of SLE due to IRF5. In African–American patients with SLE a similar relationship between serology and IFNα was observed, although the previously described European ancestry-risk haplotype was present at admixture proportions in African–American subjects and absent in African patients with SLE.
The authors define a novel risk haplotype of IRF5 that is associated with anti-dsDNA antibodies and show that risk of SLE due to IRF5 genotype is largely dependent upon particular auto-antibodies. This suggests that auto-antibodies are directly pathogenic in human SLE, resulting in increased IFNα in cooperation with particular combinations of IRF5 functional genetic elements.
SLE is a systemic autoimmune disorder affecting multiple organ systems including the skin, musculoskeletal, renal and haematopoietic systems. Humoral autoimmunity is a hallmark of SLE, and patients frequently have circulating auto-antibodies directed against dsDNA, as well as RNA binding proteins (RBP). Anti-RBP autoantibodies include antibodies which recognize Ro, La, Smith (anti-Sm), and ribonucleoprotein (anti-nRNP), collectively referred to as anti-retinol-binding protein). Anti-retinol-binding protein and anti-dsDNA auto-antibodies are rare in the healthy population.1 These auto-antibodies can be present in sera for years preceding the onset of clinical SLE illness2 and are likely pathogenic in SLE.34
Pulmonary hypertension (PH) is an increasingly recognized complication of systemic lupus erythematosus (SLE). To develop a more comprehensive understanding of the clinical and pathological characteristics of pulmonary hypertension associated with systemic lupus erythematosus (PH/SLE) in the Chinese population, a systematic review of the literature up to 2012 was conducted. Six hundred and forty-two Chinese PH/SLE cases from 22 studies were identified as well documented and further analyzed. Transthoracic echocardiography (TTE), X-ray, electrocardiogram and right heart catheterization (RHC) were performed to diagnose PH in SLE patients. The mean age of subjects was 35.5 years, the male to female ratio was 1:14, and the mean duration of SLE when PH was diagnosed was 10.7 years. The prevalence of PH in SLE was 2.8–23.3 %. Symptoms were usually nonspecific, and the observed clinical characteristics include Raynaud’s phenomenon (41.4 %), serous effusion (27.7 %), positive RNP (51.5 %) and positive ACL (46.6 %). Gold standard RHC is strongly recommended, especially for those who had resting pulmonary arterial systolic pressure >30 mmHg on TTE with the aforementioned clinical characteristics. Corticosteroids, immunosuppressants and vasodilators were the most common medications employed in treatment. Early identification and standard PH treatment with intensive SLE treatment can improve the prognosis.
Pulmonary hypertension; Systemic lupus erythematosus; Raynaud’s phenomenon; Serous effusion; Right heart catheterization; Prognosis
The hypothesis that lymphocytotoxic antibodies are associated with neuropsychiatric involvement in systemic lupus erythematosus (NP-SLE) is re-evaluated in this study. In an unselected cohort of 98 women with SLE a cross-sectional study has been performed to analyse associations among standardised clinical, neurological, and neuropsychological assessments and lymphocytotoxic antibodies measured by microcytotoxicity assay. Fifty patients showed objective clinical evidence of continuing or past NP-SLE and 54 patients had cognitive impairment. In accordance with previous observations 44% (24/54) of the cognitively impaired group did not have clinically detectable evidence of NP-SLE. Although lymphocytotoxic antibodies were found to be only marginally more prevalent in those patients with a clinical diagnosis of NP-SLE than in those without (32% v 23%), these antibodies were significantly associated with cognitive impairment (chi 2 = 5.42; p less than 0.02). No association was detected between lymphocytotoxic antibodies and either overall systemic disease activity or other organ system involvement, suggesting that the association between lymphocytotoxic antibodies and cognitive dysfunction in SLE is specific.
Interferon α (IFN-α) levels are elevated in many patients with systemic lupus erythematosus (SLE); however it is not known whether high serum IFN-α activity is a cause or a result of the disease. We studied 266 SLE patients and 405 of their healthy relatives, and frequently found high serum IFN-α activity in both patients and healthy relatives as compared to healthy unrelated individuals. High IFN-α activity was clustered in specific families in both SLE patients and their healthy first-degree relatives, suggesting a heritable trait. Heritability was also supported by quantitative familial correlation of IFN-α activity, concordance in affected sib pairs and frequent transmission of the high IFN-α activity trait from parents to offspring. Autoantibodies to RNA-binding proteins and double-stranded DNA were associated with high IFN-α activity in SLE patients; however these autoantibodies were very uncommon in healthy family members and did not explain the observed familial correlations. The frequency of high IFN-α activity was similar across all studied ethnic backgrounds. These data suggest that high serum IFN-α activity is a complex heritable trait, which plays a primary role in SLE pathogenesis.
interferon α; systemic lupus erythematosus; genetics; epidemiology; autoantibodies
A cardinal feature of systemic lupus erythematosus (SLE) is the development of autoantibodies. The first autoantibodies described in patients with SLE were those specific for nuclei and DNA, but subsequent work has shown that individuals with this disease produce a panoply of different autoantibodies. Thus, one of the constant features of SLE is a profound breakdown in tolerance in the antibody system. The appearance of self-reactive antibodies in SLE precedes clinical disease, but where in the B cell pathway tolerance is first broken has not been defined. In healthy humans, autoantibodies are removed from the B cell repertoire in two discrete early checkpoints in B cell development. We found these checkpoints to be defective in three adolescent patients with SLE. 25–50% of the mature naive B cells in SLE patients produce self-reactive antibodies even before they participate in immune responses as compared with 5–20% in controls. We conclude that SLE is associated with abnormal early B cell tolerance.
Systemic lupus erythematosus (SLE) is a clinically and serologically complex disease that demonstrates clinical, epidemiological and genetic differences among racial and ethnic groups. Some autoantibodies are useful for diagnosis of the illness. Others are clinically important because of associations with a particular manifestation of SLE. Antibodies to RNA helicase A (anti-RHA) comprise a newly described class of SLE autoantibodies. These antibodies have so far been found only in SLE patients and differ substantially in prevalence and nature between Mexican and white American SLE patients. Study of anti-RHA may provide insights into the origin of population differences in SLE.
To determine the risk of rare complications during pregnancy for women with systemic lupus erythematosus (SLE).
Using the Nationwide Inpatient Sample from 2000 to 2003, we compared maternal and pregnancy complications for all pregnancy-related admissions for women with and without SLE.
Out of over 16.7 million admissions for childbirth over the 4 years, 13,555 were to women with SLE. Maternal mortality was 20-fold higher among women with SLE. The risks for thrombosis, infection, thrombocytopenia, and transfusion were each 3–7-fold higher for women with SLE. Lupus patients also had a higher risk for cesarean sections (OR 1.7), preterm labor (OR 2.4), and preeclampsia (OR 3.0) than other women. Women with SLE were more likely to have other medical conditions, including diabetes, hypertension, and thrombophilia, that are associated with adverse pregnancy outcomes.
Women with SLE are at increased risk for serious medical and pregnancy complications during pregnancy.
pregnancy; systemic lupus erythematosus; maternal mortality; preeclampsia