Association of chemokine CXCL12-3'G801A polymorphism with systemic lupus erythematosus in a Han Chinese population

Pathogenesis of lupus nephritis: the contribution of immune and kidney resident cells

PURPOSE OF REVIEW

Lupus nephritis is associated with significant mortality and morbidity. We lack effective therapeutics and biomarkers mostly because of our limited understanding of its complex pathogenesis. We aim to present an overview of the recent advances in the field to gain a deeper understanding of the underlying cellular and molecular mechanisms involved in lupus nephritis pathogenesis.

RECENT FINDINGS

Recent studies have identified distinct roles for each resident kidney cell in the pathogenesis of lupus nephritis. Podocytes share many elements of innate and adaptive immune cells and they can present antigens and participate in the formation of crescents in coordination with parietal epithelial cells. Mesangial cells produce pro-inflammatory cytokines and secrete extracellular matrix contributing to glomerular fibrosis. Tubular epithelial cells modulate the milieu of the interstitium to promote T cell infiltration and formation of tertiary lymphoid organs. Modulation of specific genes in kidney resident cells can ward off the effectors of the autoimmune response including autoantibodies, cytokines and immune cells.

SUMMARY

The development of lupus nephritis is multifactorial involving genetic susceptibility, environmental triggers and systemic inflammation. However, the role of resident kidney cells in the development of lupus nephritis is becoming more defined and distinct. More recent studies point to the restoration of kidney resident cell function using cell targeted approaches to prevent and treat lupus nephritis.

Relationship between rs1801157 polymorphism in stromal cell-derived factor gene and systemic lupus erythematosus risk

Objective

Present meta-analysis was performed to investigate the role of stromal cell-derived factor (SDF-1) gene rs1801157 polymorphism in systemic lupus erythematosus (SLE).

Results

Five publications with 1,087 cases and 1,181 controls were incorporated in this meta-analysis. Overall, a marginal association between SDF-1 rs1801157 polymorphism and reduced SLE risk was found under GA vs. GG model (OR = 0.84, 95% CI = 0.70–1.00). A similar result was also observed in Asian subgroup under the same comparison after stratification analysis by ethnicity (OR = 0.79, 95% CI = 0.63–1.00).

Materials and Methods

All included studies were retrieved from PubMed, EMBASE, Google Scholar Web and Chinese National Knowledge Infrastructure (CNKI). Odds ratios (ORs) with 95% confidence intervals (95% CIs) were calculated to appraise the strength of association between SDF-1 rs1801157 polymorphism and SLE risk. The stratification analysis was also performed according to ethnicity. In addition, heterogeneity was examined with Q test, and sensitivity analysis was used to test the stability of final results. Begg’s funnel plot and Egger’s test were adopted to evaluate publication bias.

Conclusions

SDF-1 rs1801157 polymorphism may not influence the risk of SLE. However, more studies with larger sample sizes involving different populations are needed to further explore this issue.

The Association of Chemokine Gene Polymorphisms with VKH and Behcet's Disease in a Chinese Han Population

To investigate the association of chemokine gene polymorphisms and Behcet's disease (BD) and Vogt Koyanagi Harada (VKH) disease in a Chinese Han population. A case-control study was performed. Three hundred and seventy-one BD patients, 371 VKH disease patients, and 605 healthy controls were recruited to determine genetic variants of 26 SNPs in 12 chemokine genes with iPLEX Gold genotyping assay and Sequenom MassARRAY or TaqMan SNP assays. In this study, P_uncorr values showed a weak association of five SNPs of five genes in BD and three SNPs of three genes in VKH disease. However, after Bonferroni correction, the 26 investigated SNPs showed no significant differences in genetic variants, including genotype and allele frequencies, between BD or VKH disease patients and healthy individuals. Haplotype analysis for the chemokine genes showed a significant association with the TC haplotype of CXCL12 in VKH. Stratified gender analysis and genotype-phenotype analysis were conducted to analyze the association of the 26 SNPs of 12 chemokine genes with BD and VKH disease. However, no significant association was observed after Bonferroni correction. This study showed no association of 26 SNPs in 12 chemokine genes with both BD and VKH disease in a Chinese Han population.

Pathogenesis of cutaneous lupus erythema associated with and without systemic lupus erythema

Cutaneous lupus erythematosus (CLE) can be an individual disease only involving skin, or presents as part of the manifestations of SLE. A small proportion of CLE may progress into SLE, however, the underlying pathogenic mediators remain elusive. By only including researches that clearly described if the subtypes of CLE presented by enrolled subjects was associated with or without SLE, we provided an overview of antibodies, inflammatory cells and inflammatory molecular mediators identified in blood and skin that were possibly involved in lupus skin damages. IgG autoantibodies are crucial for the development of CLE associated with SLE, but the circulating inflammatory cells and molecular mediators require further studies to provide definitive proof for their association with skin damages. Discoid lupus erythematosus (DLE) is the most common subtype of CLE. For DLE without associated with SLE (CDLE), it is lack of evidences if autoantibodies and circulating inflammatory cells are involved in the pathogenesis or not, but is clear that the cutaneous inflammatory infiltrates are dominated by Th1, but not Th17 cells in contrast to the various complex profile in SLE. As the major target cells in skin, keratinocytes may participate the pathophysiological process by increase cell apoptosis and the production of proinflammatory cytokines in SLE and CDLE. Insights into the similarities and differences of the pathogenesis of CLE and CLE associated with SLE will also improve our therapeutic strategies for CLE that is currently adopted from SLE, and prevent the progression of CLE to SLE by providing interventions within an appropriate window of disease development.

Genetics of Lupus Nephritis: Clinical Implications

Systemic lupus erythematosus is a heterogeneous autoimmune disease marked by the presence of pathogenic autoantibodies, immune dysregulation, and chronic inflammation that may lead to increased morbidity and early mortality from end-organ damage. More than half of all systemic lupus erythematosus patients will develop lupus nephritis. Genetic-association studies have identified more than 50 polymorphisms that contribute to lupus nephritis pathogenesis, including genetic variants associated with altered programmed cell death and defective immune clearance of programmed cell death debris. These variants may support the generation of autoantibody-containing immune complexes that contribute to lupus nephritis. Genetic variants associated with lupus nephritis also affect the initial phase of innate immunity and the amplifying, adaptive phase of the immune response. Finally, genetic variants associated with the kidney-specific effector response may influence end-organ damage and the progression to end-stage renal disease and death. This review discusses genetic insights of key pathogenic processes and pathways that may lead to lupus nephritis, as well as the clinical implications of these findings as they apply to recent advances in biologic therapies.

Lack of an Association between the SDF-1 rs1801157 Polymorphism and Coronary Heart Disease: A Meta-Analysis

Recent studies have shown that the single-nucleotide polymorphism (SNP) rs1801157 in the stromal cell-derived factor (SDF)-1 gene is associated with susceptibility to coronary heart disease (CHD). However, published studies have shown inconsistent results. Therefore, a meta-analysis was carried out to evaluate the association between rs1801157 and CHD in the literature. A systematic literature search was performed using the PubMed, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure and Chinese Wan Fang databases. Heterogeneity and publication bias were also evaluated. Seven eligible studies that involved 4656 cases and 2654 controls were finally included in this meta-analysis. Overall, the results showed that the rs1801157 polymorphism was not statistically associated with the risk of CHD under all genetic models but that rs1801157 was associated with decreased susceptibility to myocardial infarction (MI) in subgroup analyses. Moreover, no association was found between rs1801157 and the susceptibility to CHD in either Caucasians or Asians. In conclusion, our meta-analysis demonstrated that the rs1801157 polymorphism is not associated with the susceptibility to CHD but may be associated with a decreased risk of MI. However, further large-scale, case-control studies with rigorous designs should be conducted to confirm these conclusions.