Genetic risk and longitudinal disease activity in systemic lupus erythematosus using targeted maximum likelihood estimation.

Systemic lupus erythematous (SLE) is a chronic autoimmune disease associated with genetic and environmental risk factors. However, the extent to which genetic risk is causally associated with disease activity is unknown. We utilized longitudinal-targeted maximum likelihood estimation to estimate the causal association between a genetic risk score (GRS) comprising 41 established SLE variants and clinically important disease activity as measured by the validated Systemic Lupus Activity Questionnaire (SLAQ) in a multiethnic cohort of 942 individuals with SLE. We did not find evidence of a clinically important SLAQ score difference (>4.0) for individuals with a high GRS compared with those with a low GRS across nine time points after controlling for sex, ancestry, renal status, dialysis, disease duration, treatment, depression, smoking and education, as well as time-dependent confounding of missing visits. Individual single-nucleotide polymorphism (SNP) analyses revealed that 12 of the 41 variants were significantly associated with clinically relevant changes in SLAQ scores across time points eight and nine after controlling for multiple testing. Results based on sophisticated causal modeling of longitudinal data in a large patient cohort suggest that individual SLE risk variants may influence disease activity over time. Our findings also emphasize a role for other biological or environmental factors.

Meta-analysis of the TNFAIP3 region in psoriasis reveals a risk haplotype that is distinct from other autoimmune diseases.

Tumor necrosis factor alpha-inducible protein 3 (TNFAIP3) encodes a ubiquitin-modifying protein, A20, that is a critical regulator of inflammatory responses. TNFAIP3 polymorphisms are associated with the susceptibility to multiple autoimmune diseases (AIDs) including psoriasis, systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis and celiac disease. In order to refine the TNFAIP3 association signal in psoriasis and identify candidate causal variants, we performed imputation and meta-analysis of the TNFAIP3 region in five European ancestry cohorts totaling 4704 psoriasis cases and 7805 controls. We identified 49 variants whose significance exceeded a corrected Bonferroni threshold, with the top variant being rs582757 (P = 6.07 × 10(-12), odds ratio (OR) = 1.23). Conditional analysis revealed a suggestive independent association at rs6918329 (P(cond) = 7.22 × 10(-5), OR = 1.15). Functional annotation of the top variants identified several with a strong evidence of regulatory potential and several within long noncoding RNAs. Analysis of TNFAIP3 haplotypes revealed that the psoriasis risk haplotype is distinct from other AIDs. Overall, our findings identify novel candidate causal variants of TNFAIP3 in psoriasis and highlight the complex genetic architecture of this locus in autoimmune susceptibility.

Breast cancer in systemic lupus erythematosus.

OBJECTIVE: Evidence points to a decreased breast cancer risk in systemic lupus erythematosus (SLE). We analyzed data from a large multisite SLE cohort, linked to cancer registries. METHODS: Information on age, SLE duration, cancer date, and histology was available. We analyzed information on histological type and performed multivariate logistic regression analyses of histological types according to age, SLE duration, and calendar year. RESULTS: We studied 180 breast cancers in the SLE cohort. Of the 155 cases with histology information, 11 were referred to simply as 'carcinoma not otherwise specified'. In the remaining 144 breast cancers, the most common histological type was ductal carcinoma (n = 95; 66%) followed by lobular adenocarcinoma (n = 11; 8%), 15 cancers were of mixed histology, and the remaining ones were special types. In our regression analyses, the independent risk factors for lobular versus ductal carcinoma was age [odds ratio (OR) 1.07, 95% confidence interval (CI) 1.01-1.14] and for the 'special' subtypes it was age (OR 1.06, 95% CI 1.01-1.10) and SLE duration (OR 1.05, 95% CI 1.00-1.11). CONCLUSIONS: Generally, up to 80% of breast cancers are ductal carcinomas. Though our results are not definitive, in the breast cancers that occur in SLE, there may be a slight decrease in the ductal histological type. In our analyses, age and SLE duration were independent predictors of histological status.

Genome-wide association analysis implicates the involvement of eight loci with response to tocilizumab for the treatment of rheumatoid arthritis.

Rheumatoid arthritis (RA) is an immune-mediated inflammatory disease affecting the joints. A heterogeneous response to available therapies demonstrates the need to identify those patients likely to benefit from a particular therapy. Our objective was to identify genetic factors associated with response to tocilizumab, a humanized monoclonal antibody targeting the interleukin (IL)-6 receptor, recently approved for treating RA. We report the first genome-wide association study on the response to tocilizumab in 1683 subjects with RA from six clinical studies. Putative associations were identified with eight loci, previously unrecognized as linked to the IL-6 pathway or associated with RA risk. This study suggests that it is unlikely that a major genetic determinant of response exists, and it illustrates the complexity of performing genome-wide association scans in clinical trials.

American College of Rheumatology classification criteria for Sjögren's syndrome: a data-driven, expert consensus approach in the Sjögren's International Collaborative Clinical Alliance cohort.

OBJECTIVE: We propose new classification criteria for Sjögren's syndrome (SS), which are needed considering the emergence of biologic agents as potential treatments and their associated comorbidity. These criteria target individuals with signs/symptoms suggestive of SS. METHODS: Criteria are based on expert opinion elicited using the nominal group technique and analyses of data from the Sjögren's International Collaborative Clinical Alliance. Preliminary criteria validation included comparisons with classifications based on the American­European Consensus Group (AECG) criteria, a model-based "gold standard"obtained from latent class analysis (LCA) of data from a range of diagnostic tests, and a comparison with cases and controls collected from sources external to the population used for criteria development. RESULTS: Validation results indicate high levels of sensitivity and specificity for the criteria. Case definition requires at least 2 of the following 3: 1) positive serum anti-SSA and/or anti-SSB or (positive rheumatoid factor and antinuclear antibody titer >1:320), 2) ocular staining score >3, or 3) presence of focal lymphocytic sialadenitis with a focus score >1 focus/4 mm2 in labial salivary gland biopsy samples. Observed agreement with the AECG criteria is high when these are applied using all objective tests. However, AECG classification based on allowable substitutions of symptoms for objective tests results in poor agreement with the proposed and LCA-derived classifications. CONCLUSION: These classification criteria developed from registry data collected using standardized measures are based on objective tests. Validation indicates improved classification performance relative to existing alternatives, making them more suitable for application in situations where misclassification may present health risks.

Sequencing of TNFAIP3 and association of variants with multiple autoimmune diseases.

The TNFAIP3 locus at 6q23, encoding A20, has been associated with multiple autoimmune diseases (AIDs). In this study, we sequence the coding portions of the gene to identify contributing causal polymorphisms that may explain some of the observed associations. A collection of 123 individuals from the Multiple Autoimmune Disease Genetics Consortium (MADGC) collection, each with multiple AIDs (mean=2.2 confirmed diagnoses), and 397 unrelated healthy controls were used for initial sequencing. A total of 32 polymorphisms were identified in the sequencing experiments, including 16 novel and 11 coding variants. Association testing in the entire MADGC collection (1,008 Caucasians with one or more AIDs and 770 unaffected family controls) revealed association of a novel intronic insertion-deletion polymorphism with rheumatoid arthritis (RA) (odds ratio (OR)=2.48, P=0.041). Genotyping of the most common coding polymorphism, rs2230926, in the MADGC collection and additional control individuals revealed a significant association with Sjögren's syndrome (OR=3.38, P=0.038), Crohn's disease (OR=2.25, P=0.041), psoriasis (OR=0.037, P=0.036) and RA (OR=1.9, P=0.025). Finally, haplotype and additional testing of polymorphisms revealed that cases were enriched for 5' and 3' untranslated region variants (one-sided P-value=0.04), but not specifically for common (>2% minor allele frequency), rare, exonic, intronic, non-synonymous or synonymous variants.

Risk and protective factors for thrombosis in systemic lupus erythematosus: results from a large, multi-ethnic cohort.

OBJECTIVES: Few studies have examined thrombosis in systemic lupus erythematosus (SLE), none have included Asian-Americans, and most have had small sample sizes. We analysed risk factors for thrombosis in a large, multi-ethnic SLE cohort. METHODS: We studied 1930 SLE subjects, including Caucasians, African-Americans, Asian-Americans and Hispanics. Data were derived from questionnaires and medical records. Documented history of thrombosis was the primary outcome. Explanatory variables included age at SLE diagnosis, gender, ethnicity, disease duration, smoking, antiphospholipid antibody (aPL) status, nephritis and specific medications. RESULTS: Smoking (OR 1.26, p = 0.011), longer disease duration (OR 1.26 per 5 years p = 0.027 x 10(-7)), nephritis (OR 1.35, p = 0.036), aPL positivity (OR 3.22, p<10(-9)) and immunomodulating medication use (OR 1.40, p = 0.011) were statistically significant risk factors for thrombosis. Younger age at SLE onset was protective (OR 0.52 for age

Smoking interacts with genetic risk factors in the development of rheumatoid arthritis among older Caucasian women.

OBJECTIVE: To determine whether the impact of tobacco exposure on rheumatoid arthritis (RA) risk is influenced by polymorphisms at the HLA-DRB1 and glutathione S-transferase M1 (GSTM1) loci. METHODS: Subjects were participants from a case-control study nested within the Iowa Women's Health Study, a population based, prospective cohort study of postmenopausal women. Incident RA cases (n = 115) were identified and medical records reviewed to confirm RA diagnosis. Controls without RA (n = 466) were matched with RA cases by age and ethnic background. HLA-DRB1 typing classified subjects according to the presence of alleles encoding the RA "shared epitope" (SE) sequence. GSTM1 was genotyped using a multiplex polymerase chain reaction assay. Conditional logistic regression was used to estimate the odds ratios (ORs) and 95% confidence intervals. RESULTS: Strong positive associations of smoking (OR = 6.0, p = 0.004), SE positivity (OR = 4.6, p = 0.0006), and GSTM1 null genotype (OR = 3.4, p = 0.007) with risk of RA, and significant gene-environment interactions (smoking by SE interaction p = 0.034; smoking by GSTM1 interaction p = 0.047) were observed. Stratified analyses indicated that exposure to tobacco smoke primarily increased the risk of RA among subjects who lacked genetic risk factors for the disease (that is, SE negative or GSTM1 present). CONCLUSIONS: Although these findings require confirmation in other groups, the results support the importance of considering both genetic and environmental factors, and also their interaction, in studies of complex diseases like RA.

Association of smoking with dsDNA autoantibody production in systemic lupus erythematosus.

OBJECTIVE: To determine whether exposure to tobacco smoke is associated with double stranded DNA (dsDNA) seropositivity in patients with systemic lupus erythematosus (SLE). METHODS: Medical record review was used to confirm the diagnosis of SLE and evaluate dsDNA antibody status. Smoking status at the time of autoantibody testing was assessed by patients' questionnaire responses. Multivariate regression analysis was used to determine whether exposure to tobacco smoke is associated with dsDNA seropositivity, while controlling for sex and age at SLE diagnosis. RESULTS: A significantly higher risk of dsDNA seropositivity in current smokers than never smokers (odds ratio (OR) = 4.0, 95% confidence interval (CI) 1.6 to 10.4) was shown by multivariate analysis. Current smokers were found to be at higher risk for dsDNA seropositivity than former smokers (OR = 3.0, 95% CI 1.3 to 7.1). The association between current smoking and dsDNA seropositivity remained significant after adjustment for sex, age at SLE diagnosis, amount smoked, age when smoking began, and the duration of smoking cessation (for former smokers). CONCLUSION: The association of smoking with dsDNA seropositivity provides insight into the potential mechanisms underlying autoantibody formation. This information may also serve as a possible point of intervention to prevent disease or target treatment.

Genetic risk factors for infection in patients with early rheumatoid arthritis.

We analyzed clinical and genetic factors contributing to infections in 457 subjects with early rheumatoid arthritis (RA) enrolled in a prospective, 1-year clinical trial of methotrexate and the TNF inhibitor etanercept. Subjects were genotyped for the following single nucleotide polymorphisms (SNPs): (TNF -308, -238, and + 488); lymphotoxin-alpha (LTA) (LTA + 249, + 365, and + 720); and Fc gamma receptors FCGR2A 131 H/R; FCGR3A 176 F/V; and FCGR3B NA 1/2 and genotypes were correlated with infections. At least one URI was noted in 52% of subjects (99/191) with the NA2/NA2 genotype of the neutrophil-specific FCGR3B gene, compared to 42% (77/181) of those with the NA1/NA2 genotype and 39% (23/59) of those with the NA1/NA1 genotype (P = 0.038). Urinary tract infection (UTI) was associated with the TNF -238 A (odds ratio(OR) 2.56, 95% confidence interval (CI) 1.05-6.25) and LTA +365 C (OR 1.73, 95% CI 1.07-2.79) alleles, and marginally with the FCGR3A F allele (OR 1.72, 95% CI 0.99-3.00). There was a striking linear correlation between UTI and the number of risk alleles defined by these three SNPs (P < 0.001), suggesting an additive effect on susceptibility. These findings have important implications for the role of genetics in susceptibility to bacterial and viral infections.

Mortality risk associated with rheumatoid arthritis in a prospective cohort of older women: results from the Iowa Women's Health Study.

OBJECTIVE: To determine whether rheumatoid arthritis (RA) is associated with excess mortality among older women. METHODS: RA associated mortality was examined in a prospective cohort study that was started in 1986, and included 31 336 women aged 55-69 years without a history of RA at baseline. Up to 1997, 158 cases of RA were identified and validated against medical records. The relative risk (RR) and 95% confidence interval (CI) were calculated as measures of association between RA onset and subsequent mortality (overall and cause-specific) using Cox proportional hazards regression. RESULTS: Compared with non-cases, women developing RA during follow up had a significantly increased mortality risk (RR=1.52; 95% CI 1.05 to 2.20). Mortality was higher among rheumatoid factor (RF) positive cases (RR=1.90; 95% CI 1.24 to 2.92) than among RF negative cases (RR=1.00; 95% CI 0.45 to 1.99). There were trends towards increased proportions of RA related deaths from infection (RR=3.61; 95% CI 0.89-14.69) and circulatory disease (RR=1.46; 95% CI 0.76 to 2.81) but not malignancy (RR=0.97; 95% CI 0.46 to 2.04). CONCLUSIONS: RA was associated with significantly increased mortality in a cohort of older women, and the association appeared to be restricted to those with RF positive disease.

Association of angiotensin-converting enzyme polymorphisms with systemic lupus erythematosus and nephritis: analysis of 644 SLE families.

Angiotensin II is a strong candidate for the perpetuation of autoimmunity, nephritis and visceral damage in systemic lupus erythematosus (SLE). Our goal was to determine whether angiotensin-converting enzyme (ACE) gene polymorphisms are associated with SLE and/or lupus nephritis (LN). We genotyped 644 SLE patients and 1130 family members for three ACE gene polymorphisms: Alu insertion/deletion (I/D), 23949 (CT)(2/3) and 10698 (G)(3/4). All patients met the American College of Rheumatology (ACR) criteria for SLE, and all LN patients met ACR renal criteria and/or had biopsy evidence of LN. We used the transmission/disequilibrium test (TDT) to examine associations between each polymorphism and SLE, including Caucasian, non-Caucasian, and LN subgroups. We also examined transmission of haplotypes defined by these polymorphisms. The ACE I/D polymorphism was associated with SLE among non-Caucasians (61% transmission, P = 0.026) and the 23949 (CT)(2/3) polymorphism was associated with LN among non-Caucasians (69% transmission, P = 0.014). Several haplotypes defined by these 2 markers demonstrated strikingly increased transmission among non-Caucasians (81% - 66% transmission, P = 0.0046 to 0.010). Due to the choice of study design and analytic method these results are unlikely to be due to population admixture. Our findings suggest that DNA sequence variation in the ACE gene influences the risk of developing SLE and LN.

Tumor necrosis factor a microsatellite polymorphism is associated with rheumatoid arthritis severity through an interaction with the HLA-DRB1 shared epitope.

OBJECTIVE: To determine whether tumor necrosis factor microsatellite a (TNFa) polymorphism is associated with severity of rheumatoid arthritis (RA), and to examine the evidence for interaction between TNFa and the HLA-DRB1 shared epitope (SE). METHODS: One hundred seventy-one community-based white female RA patients were genotyped for both TNFa and HLA-DRB1 alleles. We performed pairwise association analyses, stratified analyses, and multivariate logistic regressions to determine whether TNFa was associated with 4 measures of RA severity, and whether there was significant interaction between TNFa and the HLA-DRB1 SE. RESULTS: Simple pairwise analyses did not reveal significant association between TNFa polymorphism and RA severity. However, when the data were stratified by the presence versus absence of the SE, striking associations were observed between TNFa allele 11 (TNFa11) and RA severity. These analyses also demonstrated significant interaction between TNFa11 and the SE (P = 0.07-0.005), and this was confirmed in our multivariate regressions. Specifically, the most severe outcomes were observed among individuals who had inherited both TNFa11 and the SE (61-71% had severe RA based on 1 of the 4 outcomes). In contrast, individuals who had inherited TNFa11 in the absence of the SE had the best outcomes (8-21% with severe RA). The odds ratios comparing these 2 groups ranged from 8.8 to 22.7 for the 4 severity measures. The differential effect of TNFa11 according to the presence versus absence of the SE (and vice versa) illustrated their interaction with respect to RA severity. CONCLUSION: The data suggest that TNFa is associated with RA severity through an interaction with the HLA-DRB1 SE.

Outcome of renal transplantation in ninety-seven cyclosporine-era patients with systemic lupus erythematosus and matched controls.

OBJECTIVE: To evaluate the effectiveness of renal transplantation in systemic lupus erythematosus (SLE). METHODS: A total of 97 SLE patients who underwent renal transplantation between January 1984 and September 1996 were selected for study and were matched with a group of non-SLE controls (1 control for each SLE patient) who also received transplants during that period. SLE patients and controls were matched on 6 covariates: age, sex, race, type of allograft (cadaveric versus living-related), number of previous transplants, and year of transplantation. All study subjects received either cyclosporine or FK-506/tacrolimus as part of their immunosuppressive regimen. In a rigorous medical records review, the status of each allograft and the cause of each graft loss was determined. Using a stratified Cox proportional hazards model, the transplantation outcomes of the SLE patients were compared with those of the controls. The effects of 9 individual variables on transplantation outcomes were also examined, and the statistically significant variables were compared in a stratified, multivariate Cox proportional hazards model. RESULTS: The control group included patients with 20 different causes of end-stage renal disease (ESRD). The mean followup times for the SLE patients and controls were 323 weeks and 320 weeks, respectively. During the followup period, 52 SLE patients and 37 controls lost their allografts. The 1-, 2-, 5-, and 10-year allograft survival probabilities for the 2 groups (SLE versus controls) were as follows: 81.7% versus 88.2% (1-year); 74.7% versus 84.4% (2-year); 45.9% versus 75.0% (5-year); and 18.5% versus 34.8% (10-year). In the multivariate model, the relative hazard of allograft loss associated with SLE as the cause of ESRD was 2.1 (95% confidence interval 1.06-4.06, P = 0.0328). The total number of HLA mismatches, smoking status, and delayed allograft function were also associated with allograft loss in the multivariate model. CONCLUSION: Compared with matched controls, renal transplant patients with SLE had inferior transplantation outcomes, with more than twice the risk of allograft loss.

Inheritance of the shared epitope and long-term outcomes of rheumatoid arthritis among community-based Caucasian females.

Multiple HLA-DRB1 alleles encoding a shared epitope (SE) at amino acid positions 70-74 are associated with susceptibility and severity of rheumatoid arthritis (RA). We examined the relationship between the number and DRB1 genotype of SE alleles inherited and long-term outcomes of 180 community-based, Caucasian female RA patients followed annually for up to 12 years. Outcomes examined were physician assessment of RA course; annual measures of pain, function, and number of painful joint groups; history of joint surgery; and resource utilization. Models accounted for correlation among serial observations for the same patient and adjusted for patient age and disease stage. We examined two genetic models: a SE model in which patients were classified according to the number of SE copies inherited and a genotype model in which patients were categorized into one of six groups based on the inherited DRB1 genotype. We used likelihood ratio tests to compare these genetic models and to compare alternative model specifications. Our results demonstrate strong associations between inheritance of the SE and long-term outcomes of community-based Caucasian females with RA. However, the pattern of results is not consistent across the outcomes. An additive model of risk is apparent for history of joint surgery and RA hospitalization. In contrast, a near reversal of this pattern is apparent for function, joint pain, pain rating, and RA physician visits. Finally, although the genotype model did not appear to be a better predictive model for RA outcomes overall, it did reveal some striking heterogeneity of SE alleles that was masked by the more parsimonious SE model. For example, the odds ratio (OR) for joint surgery for patients with 2 SE copies (OR = 3.16) reflects an average of 2 very different ORs when patients are further categorized according to genotype groups 4 and 5 (OR = 1.3 and 11.9, respectively).

Frequency of recurrent lupus nephritis among ninety-seven renal transplant patients during the cyclosporine era.

OBJECTIVE: To determine the frequency of recurrent lupus nephritis (LN) in patients with systemic lupus erythematosus (SLE) who underwent renal transplantation. METHODS: We reviewed the posttransplant clinical course and renal biopsy results in 97 consecutive SLE patients who underwent a total of 106 renal transplantation procedures at our center from January 1984 to September 1996. RESULTS: There were 81 female and 16 male patients, with a mean age of 35 years. Mean duration of dialysis prior to transplantation was 33.5 months; 9 patients were never dialyzed. In all patients, the disease was clinically and serologically quiescent at the time of transplantation. The mean posttransplantation followup period was 62.6 months. Patients underwent a total of 143 posttransplant biopsies. Nine patients had pathologic evidence of recurrent LN. Six of the patients with recurrence had cadaveric grafts, 2 had living-related grafts, and 1 had a living-unrelated graft. Recurrence occurred an average of 3.1 years after transplantation; the longest interval was 9.3 years and the shortest, 5 days. Histopathologic diagnoses on recurrence included diffuse proliferative glomerulonephritis, focal proliferative glomerulonephritis, membranous glomerulonephritis, and mesangial glomerulonephritis. In 4 patients, recurrent LN contributed to graft loss. Three of the patients with recurrence had serologic evidence of active lupus, but only 1 had symptoms of active lupus (arthritis). Three patients who lost their grafts secondary to recurrent LN underwent second renal transplantation procedures and had functioning grafts at 7, 30, and 35 months, respectively. CONCLUSION: In the largest single medical center series of renal transplant patients with SLE, recurrent LN was more common than reported in the literature, but was not always associated with allograft loss. Recurrent LN was often present in the absence of clinical and serologic evidence of active SLE.

Two genitourinary manifestations of Wegener's granulomatosis.

Genitourinary manifestations of Wegener's granulomatosis (WG) are rare. We report 2 unusual cases of genitourinary WG, one in which the diagnosis was suggested by a cervical biopsy, and one case of recurrent WG presenting exclusively at a genitourinary site while the patient was taking methotrexate for maintenance of remission.

Relationship of education level to treatment received for rheumatoid arthritis.

OBJECTIVE: To determine whether treatment received for rheumatoid arthritis (RA) is systematically different among individuals with different levels of formal education. METHODS: Using 4,455 patient-years of observational data from the University of California, San Francisco (UCSF) RA panel, we estimated the relationship between patients' education level and treatment received for RA. We define RA treatment broadly in terms of both the use of specific medications and use of health services. Independent variables include spouse's education level, as well as demographic, clinical, and socioeconomic characteristics, which are potential cofounders of this relationship due to associations with education level or RA treatment. RESULTS: Patients with RA with higher levels of formal education are more likely to be hospitalized or to undergo surgery for RA, even after differences in demographic, clinical, and socioeconomic characteristics are taken into account. In contrast, the use of specific medications was not systematically different among individuals with different education levels. CONCLUSION: The association of education level with use of health services may partially explain the association of education with RA outcomes. Further studies are needed to test this hypothesis formally.

Eosinophilia-myalgia syndrome: the aftermath.

We report here the long-term sequelae in 22 patients with L-tryptophan-induced eosinophilia-myalgia syndrome (EMS). The mean follow-up was 23 months (range, 5 to 40 months). Myalgia, rash, pruritus, edema, and respiratory symptoms often improved with the use of corticosteroids, but fatigue and weakness persisted in most cases. Other abnormalities that commonly persisted were arthralgia, muscle-cramping, peripheral neuropathy, and thickened skin. One patient had chronic pulmonary hypertension. These findings indicate that for most patients, EMS is a chronic disorder.