Lack of replication of higher genetic risk load in men than in women with systemic lupus erythematosus

Association of TYK2 polymorphisms with autoimmune diseases: A comprehensive and updated systematic review with meta-analysis

Autoimmune diseases are characterized by the loss of self-tolerance, leading to immune-mediated tissue destruction and chronic inflammation. Tyrosine kinase 2 (TYK2) protein plays a key role in immunity and apoptosis pathways. Studies have reported associations between single nucleotide polymorphisms (SNPs) in the TYK2 gene and autoimmune diseases; however, results are still inconclusive. Thus, we conducted a systematic review followed by meta-analysis. A literature search was performed to find studies that investigated associations between TYK2 SNPs and autoimmune diseases (multiple sclerosis, systemic lupus erythematosus, Crohn’s disease, ulcerative colitis, psoriasis, rheumatoid arthritis, type 1 diabetes, and inflammatory bowel disease). Pooled odds ratios (OR) with 95 % CI were calculated using random (REM) or fixed (FEM) effects models in the Stata 11.0 Software. Thirty-four articles were eligible for inclusion in the meta-analyses, comprising 9 different SNPs: rs280496, rs280500, rs280523, rs280519, rs2304256, rs12720270, rs12720356, rs34536443, and rs35018800. Meta-analysis results showed the minor alleles of rs2304256, rs12720270, rs12720356, rs34536443, and rs35018800 SNPs were associated with protection against autoimmune diseases. Moreover, the A allele of the rs280519 SNP was associated with risk for systemic lupus erythematosus. Our meta-analyses demonstrated that the rs2304256, rs12720270, rs12720356, rs34536443, rs35018800, and rs280519 SNPs in the TYK2 gene are associated with different autoimmune diseases.

Relationship Between Genetic Risk and Age of Diagnosis in Systemic Lupus Erythematosus

OBJECTIVE

Specific risk alleles for childhood-onset systemic lupus erythematosus SLE (cSLE) vs adult-onset SLE (aSLE) patients have not been identified. The aims of this study were to determine if there is an association (1) between non-HLA-related genetic risk score (GRS) and age of SLE diagnosis, and (2) between HLA-related GRS and age of SLE diagnosis.

METHODS

Genomic DNA was obtained from 2001 multiethnic patients and genotyped using the Immunochip. Following quality control, genetic risk counting (GRCS), weighted (GRWS), standardized counting (GRSCS), and standardized weighted (GRSWS) scores were calculated based on independent single-nucleotide polymorphisms from validated SLE loci. Scores were analyzed in a regression model and adjusted by sex and ancestral population.

RESULTS

The analyzed cohort consisted of 1540 patients: 1351 females and 189 males (675 cSLE and 865 aSLE). There were significant negative associations between all non-HLA GRS and age of SLE diagnosis: P = 0.011 and r² = 0.175 for GRWS; P = 0.008 and r² = 0.178 for GRSCS; P = 0.002 and r² = 0.176 for GRSWS (higher GRS correlated with lower age of diagnosis.) All HLA GRS showed significant positive associations with age of diagnosis: P = 0.049 and r² = 0.176 for GRCS; P = 0.022 and r² = 0.176 for GRWS; P = 0.022 and r² = 0.176 for GRSCS; P = 0.011 and r² = 0.177 for GRSWS (higher GRS correlated with higher age of diagnosis).

CONCLUSION

Our data suggest that there is a linear relationship between genetic risk and age of SLE diagnosis and that HLA and non-HLA GRS are associated with age of diagnosis in opposite directions.

IKZF1 polymorphisms are associated with susceptibility, cytokine levels, and clinical features in systemic lupus erythematosus

Ikaros family zinc finger 1(IKZF1) encodes a lymphoid-restricted zinc finger transcription factor named Ikaros that regulates lymphocyte differentiation and proliferation as well as self-tolerance. Increasing evidence indicates that IKZF1 could contribute to the pathogenesis of autoimmune diseases. Recent research has provided evidence that IKZF1 might correlate with Systemic lupus erythematosus (SLE), but no clear definition has been made yet. In this study, we focus on the relationship between IKZF1 polymorphisms and SLE susceptibility, cytokine levels, and clinical characteristics in the Chinese Han population.One thousand seventy-six subjects, including 400 SLE patients and 676 healthy controls, were included in this study. Three single nucleotide polymorphisms within IKZF1 containing rs4917014, rs11980379, and rs4132601 were genotyped in all subjects by an improved multiplex ligation detection reaction technique. 143 subjects from SLE patients were randomly selected for testing the levels of serum cytokines. The clinical characteristics of SLE patients were gathered and collated from medical records. The data were analyzed mainly using SPSS20.0 (SPSS lnc., Chicago, IL).Significant relationships were observed between rs4132601 and SLE susceptibility, CD40 ligand, and malar rash (P < .001, P = .04, and P = .01, respectively). In addition, significant relationships were observed between rs4917014 and susceptibility, granzyme B level, and hematological disorder in SLE (P = .005, P = .03 and P = .005, respectively).The results further support that IKZF1 may have an important role in the development and pathogenesis of SLE. Allele G of rs4132601 and rs4917014 is related to a decreased risk of SLE occurrence and associated with clinical features in SLE patients, including CD40 ligand level, granzyme B level, malar rash, and hematological disorder, which play important roles in disease progression.

High genetic risk score is associated with early disease onset, damage accrual and decreased survival in systemic lupus erythematosus

Objectives

To investigate associations between a high genetic disease risk and disease severity in patients with systemic lupus erythematosus (SLE).

Methods

Patients with SLE (n=1001, discovery cohort and n=5524, replication cohort) and healthy controls (n=2802 and n=9859) were genotyped using a 200K Immunochip single nucleotide polymorphism array. A genetic risk score (GRS) was assigned to each individual based on 57 SLE risk loci.

Results

SLE was more prevalent in the high, compared with the low, GRS-quartile (OR 12.32 (9.53 to 15.71), p=7.9×10^–86 and OR 7.48 (6.73 to 8.32), p=2.2×10^–304 for the discovery and the replication cohorts, respectively). In the discovery cohort, patients in the high GRS-quartile had a 6-year earlier mean disease onset (HR 1.47 (1.22 to 1.75), p=4.3×10^–5), displayed higher prevalence of damage accrual (OR 1.47 (1.06 to 2.04), p=2.0×10^–2), renal disorder (OR 2.22 (1.50 to 3.27), p=5.9×10^–5), anti-dsDNA (OR 1.83 (1.19 to 2.81), p=6.1×10^–3), end-stage renal disease (ESRD) (OR 5.58 (1.50 to 20.79), p=1.0×10^–2), proliferative nephritis (OR 2.42 (1.30 to 4.49), p=5.1×10^–3), anti-cardiolipin-IgG (OR 1.89 (1.13 to 3.18), p=1.6×10^–2), anti-β₂-glycoprotein-I-IgG (OR 2.29 (1.29 to 4.06), p=4.8×10^–3) and positive lupus anticoagulant test (OR 2.12 (1.16 to 3.89), p=1.5×10^–2) compared with patients in the low GRS-quartile. Survival analysis showed earlier onset of the first organ damage (HR 1.51 (1.04 to 2.25), p=3.7×10^–2), first cardiovascular event (HR 1.65 (1.03 to 2.64), p=2.6×10^–2), nephritis (HR 2.53 (1.72 to 3.71), p=9.6×10^–7), ESRD (HR 6.78 (1.78 to 26.86), p=6.5×10^–3) and decreased overall survival (HR 1.83 (1.02 to 3.30), p=4.3×10^–2) in high to low quartile comparison.

Conclusions

A high GRS is associated with increased risk of organ damage, renal dysfunction and all-cause mortality. Our results indicate that genetic profiling may be useful for predicting outcomes in patients with SLE.

Sex Differences in Health Care Utilization, End-Stage Renal Disease, and Mortality Among Medicaid Beneficiaries With Incident Lupus Nephritis

OBJECTIVE

While systemic lupus erythematosus and lupus nephritis (LN) disproportionately affect females, previous studies suggest that males may experience poorer outcomes. We undertook this study to investigate sex differences in health care utilization, end-stage renal disease (ESRD), and mortality among patients with LN receiving Medicaid, public insurance for low-income individuals.

METHODS

Within the Medicaid Analytic eXtract (MAX) from 29 states (from 2000 to 2010), we used billing claims to identify individuals ages 5-65 years with incident LN (positive predictive value 80%). MAX data were linked to the US Renal Data System to determine ESRD and to Social Security Death Index files to determine death. We estimated adjusted incidence rate ratios (IRRs) by sex for health care utilization using Poisson regression, and we used multivariable proportional hazards models to compare risks of ESRD and death by sex.

RESULTS

Of 2,750 patients with incident LN, 283 (10%) were male. The mean ± SD follow-up period for both sexes was 3.1 ± 2.3 years. The mean ± SD age was 29.6 ± 13.9 years among females and 24.7 ± 14.1 years among males (P < 0.01). Males had fewer outpatient visits (IRR 0.88 [95% confidence interval (95% CI) 0.80-0.97]) and fewer emergency department visits (IRR 0.75 [95% CI 0.63-0.90]). The 5-year cumulative incidence of ESRD was 22.3% in males and 21.2% in females. The 5-year cumulative incidence of death was 9.4% in males and 9.8% in females. Comparing males to females, there were no sex differences in ESRD (subdistribution hazard ratio [HR] 1.05 [95% CI 0.76-1.45]) or death (HR 0.81 [95% CI 0.47-1.35]).

CONCLUSION

In this cohort of patients with incident LN, ESRD and mortality were extremely high overall but were not increased among males compared to females. In this vulnerable population, biologic and health care utilization differences by sex may not significantly affect outcomes.

Epidemiology of systemic lupus erythematosus

INTRODUCTION

Systemic lupus erythematosus (SLE) is a disease distributed worldwide, which occurs in both genders, and across racial/ethnic and age groups; however, higher rates are observed in adults, in women and in non-Caucasians. Genetic, environmental, sociodemographic and methodological issues are responsible not only for these differences but for the variable course and outcome of the disease. Non-Caucasians have a more severe disease with a higher risk for early mortality and damage accrual. Males also have a more severe disease; however, a negative impact of male gender on lupus outcomes has not been firmly established. Childhood-onset is associated with a more severe disease; moreover, it is also associated with higher damage and diminished survival; finally, late-onset lupus is mild but it is associated with higher damage accrual and a diminished survival. Areas covered: In this review, we discuss the incidence and prevalence of SLE, the impact of age, gender and race/ethnicity in SLE and in the survival of those affected. Expert commentary: Age, gender and race/ethnicity impact disease expression in SLE patients; despite improvements in survival, mortality in SLE remains almost three times higher than in the general population.

Chinese SLE Treatment and Research group (CSTAR) registry: V. gender impact on Chinese patients with systemic lupus erythematosus

Introduction

Many studies have shown that differences were observed between male and female lupus patients. Although systemic lupus erythematosus (SLE) affects mostly females (female:male ratio 9:1), male SLE patients show higher mortality due to kidney and neurological disease. Currently there are limited epidemiological data concerning lupus in the Chinese population. As such, the Chinese SLE Treatment and Research group (CSTAR) developed the first online registry of Chinese lupus patients in 2009, and represents a multicenter observational study that attempts to describe and compile the major clinical characteristics of lupus in Chinese patients.

Objective

To investigate the effect of gender on the phenotypes of Chinese SLE patients.

Patients and methods

Data for 2104 SLE patients were prospectively collected and included in the CSTAR registry. Patients fulfilled the 1997 American College of Rheumatology (ACR) SLE classification criteria. We conducted a cross-sectional case-control study to analyze patient clinical and laboratory data at onset and at enrollment. SLE disease activity scores (SLEDAI) were also measured at enrollment.

Results

This study included 1914 women and 190 men. Males and females showed no differences in mean ages at onset, delay of diagnosis and disease duration. Males presented more frequently with fever ( p = 0.003), while musculoskeletal involvement ( p = 0.001) and cytopenia ( p = 0.017) was more common in females as the initial manifestation at onset of SLE. For manifestations at enrollment, males presented more frequently with fever ( p = 0.005), renal disease ( p = 0.019), vasculitis ( p = 0.032) and neuropsychiatric lupus ( p = 0.007). For cumulative manifestations at enrollment, males presented more frequently with discoid rash ( p < 0.001) and neuropsychiatric lupus ( p = 0.036), while less frequently with arthritis ( p = 0.011). However, the laboratory data showed no significant differences between the two groups at enrollment. Males also had higher SLEDAI scores at enrollment ( p = 0.002).

Conclusions

Renal disease, vasculitis and neuropsychiatric lupus are more common in male SLE patients with higher SLEDAI scores compared to female SLE patients in China.