Update on human systemic lupus erythematosus genetics
CURRENT OPINION IN RHEUMATOLOGY
Authors: Tsao, BP
Abstract
Purpose of review Susceptibility to systemic lupus erythematosus (SLE) has a genetic component. In recent years, nine complete genome scans using family collections that differ greatly in ethnic compositions and geographic locations have identified several strong, confirmed SLE susceptibility loci. Evidence implicating individual gene polymorphisms (or haplotypes) within some of the linked intervals has been reported. This review highlights recent findings that may lead to the identification of putative genes and new insights in the pathogenesis of SLE. Recent findings Eight of the best-supported SLE susceptibility loci are 1q23, 1q25-31, 1q41-42, 2q35-37, 4p16-15.2, 6p11-21, 12p24, and 16q12. These are chromosomal regions exhibiting genome-wide significance for linkage in single studies and suggestive evidence for linkage in other samples. Linkage analyses conditioning on pedigrees in which one affected member manifesting a particular clinical condition have also yielded many chromosomal regions linked to SLE. The linked interval on chromosome 6p has been narrowed to 0.5 similar to 1.0 Mb (million basepairs) of 3 MHC class II containing risk haplotypes in white subjects. Cumulative results have shown that hereditary deficiencies of complement component C4A (a MHC class III gene) confer risk for SLE in almost all ethnic groups studied. The FcgammaR genes (located at 1q23) have been convincingly demonstrated to play an important role in susceptibility to SLE (and/or lupus nephritis). The evidence for the intronic single nucleotide polymorphism of program cell death gene 1 (PDCD1 at 2q37) to confer susceptibility is promising but not yet compelling. Within several established susceptibility loci, evidence for association of positional candidate genes is emerging. Summary Further replications of linkage and association are the immediate task. The respective contribution of each susceptibility gene, relationships between genotypes and phenotypes, and potential interactions between susceptibility gene products need to be elucidated. This line of investigation is now well poised to provide novel insights into how genetic variants can affect functional pathways leading to the development of SLE.
Association between co-stimulatory molecule gene polymorphism and acute rejection of allograft
TRANSPLANT IMMUNOLOGY
Authors: Han, Fei-fei; Fan, Hua; Wang, Zi-hui; Li, Guang-run; Lv, Ya-li; Gong, Li-li; Liu, He; He, Qiang; Liu, Li-hong
Abstract
Co-stimulatory molecules play important roles in T cell-mediated immune response and transplantation. Numerous epidemiological studies have evaluated the association between CD28, CTLA-4 gene variant and allograft rejection. However, the results of these studies on the association remain conflicting. The main purpose of this study was to integrate previous results and explore whether the CD28 IVS3 + 17T/C variant, CTLA-4, CD86 and PDCD1 gene polymorphisms were associated with allograft rejection susceptibility. PubMed and Embase (before 2014-3-25), were searched for studies on the relationship of CD28, CTLA-4, CD86 and PDCD1 gene polymorphisms and the incidence of allograft rejection susceptibility. Eligible articles were included for data extraction. The main outcome was the frequency of co-stimulate molecule gene polymorphisms between rejection and non-rejection populations. Comparison of the distribution of SNP was mainly performed using Review Manager 5.0. The odds ratio (OR) and its 95% confidence interval (95% CI) were used to assess the strength of association. Significant associations of the CD28 IVS3 + 17T/C variant with acute allograft rejection susceptibility were found (CC + CT/TT OR, 1.45; 95% CI, 1.08-1.94; P = 0.01). Also we found an association of the CD28 IVS3 +17T/C variant with kidney allograft rejection cases (CC + CT/IT OR, 1.72; 95% CI, 1.19-2.49; P = 0.004) and (C allele OR, 1.74; 95% CI, 1.11-2.75; P = 0.02), but not established for liver allograft rejection cases (CC + CT/IT OR, 1.19; 95% CI, 0.47-2.98; P = 0.72) and (C allele OR, 0.96; 95% CI, 0.67-1.39; P = 0.84). And we found an association of the CD86 + 1057G/A variant with non-allograft rejection cases (AA + AG/GG OR, 0.35; 95% CI, 0.14-0.85; P = 0.02). This meta-analysis demonstrates that the CD28 IVS3 +17T/C variant might increase acute allograft rejection risk in kidney transplant but not in liver transplant, and there was an association between CD86 + 1057G/A variant and reduced acute rejection risk. Further studies will be needed to confirm our findings. (C) 2014 Elsevier B.V. All rights reserved.