Association between genetic variants in the human leukocyte antigen-B/MICA and Takayasu arteritis in Chinese Han population

Anti-endothelial cell antibodies in pathogenesis of vasculitis

Vasculitis is a group of syndromes characterized by inflammation, presence of autoantibodies and endothelial cells (ECs) damage, which lead to stenosis or occlusion of the vascular lumen. Anti-endothelial cell antibodies (AECAs) are a heterogeneous group of autoantibodies in vasculitis. AECAs bind to antigens and membrane-bound proteins of ECs, inducing inflammation, coagulation, and apoptosis. In this review, we discuss the pathological role of AECAs in different types of vasculitis. In addition, AECAs potentially induce alterations of ECs mechanical properties, and subsequently promotes angiogenic phenotypes in the occurrence of vasculitis.

Associations between MICA and MICB Genetic Variants, Protein Levels, and Colorectal Cancer: Atherosclerosis Risk in Communities (ARIC)

BACKGROUND

The MHC class I chain-related protein A (MICA) and protein B (MICB) participate in tumor immunosurveillance and may be important in colorectal cancer, but have not been examined in colorectal cancer development.

METHODS

sMICA and sMICB blood levels were measured by SomaScan in Visit 2 (1990-92, baseline) and Visit 3 (1993-95) samples in cancer-free participants in the Atherosclerosis Risk in Communities Study. We selected rs1051792, rs1063635, rs2516448, rs3763288, rs1131896, rs2596542, and rs2395029 that were located in or in the vicinity of MICA or MICB and were associated with cancer or autoimmune diseases in published studies. SNPs were genotyped by the Affymetrix Genome-Wide Human SNP Array. We applied linear and Cox proportional hazards regressions to examine the associations of preselected SNPs with sMICA and sMICB levels and colorectal cancer risk (236 colorectal cancers, 8,609 participants) and of sMICA and sMICB levels with colorectal cancer risk (312 colorectal cancers, 10,834 participants). In genetic analyses, estimates adjusted for ancestry markers were meta-analyzed.

RESULTS

Rs1051792-A, rs1063635-A, rs2516448-C, rs3763288-A, rs2596542-T, and rs2395029-G were significantly associated with decreased sMICA levels. Rs2395029-G, in the vicinity of MICA and MICB, was also associated with increased sMICB levels. Rs2596542-T was significantly associated with decreased colorectal cancer risk. Lower sMICA levels were associated with lower colorectal cancer risk in males (HR = 0.68; 95% confidence interval, 0.49-0.96) but not in females (Pinteraction = 0.08).

CONCLUSIONS

Rs2596542-T associated with lower sMICA levels was associated with decreased colorectal cancer risk. Lower sMICA levels were associated with lower colorectal cancer risk in males.

IMPACT

These findings support an importance of immunosurveillance in colorectal cancer.

Genetic Basis of Vasculitides with Neurologic Involvement

"Vasculitides are a heterogeneous group of inflammatory diseases of blood vessels in which genetic variation plays an important role in their susceptibility and clinical spectrum. Because of the use of novel technologies and the increase of the sample size of the study cohorts, the knowledge of the genetic background of vasculitides has considerably expanded during the last years. However, few insights have been obtained regarding the genetics underlying severe clinical phenotypes, such as those related to the nervous system. In this review the authors provide an updated overview of the genetic landscape behind vasculitis predisposition and development of neurologic manifestations."

Takayasu Arteritis

Takayasu arteritis is an idiopathic granulomatous vasculitis of the aorta and its main branches and it constitutes one of the more common vasculitides in children. Inflammation and intimal proliferation lead to wall thickening, stenotic or occlusive lesions, and thrombosis, while destruction of the elastica and muscularis layers originates aneurysms and dissection. Carotid artery tenderness, claudication, ocular disturbances, central nervous system abnormalities, and weakening of pulses are the most frequent clinical features. The diagnosis is usually confirmed by the observation of large vessel wall abnormalities: stenosis, aneurysms, occlusion, and evidence of increased collateral circulation in angiography, MRA or CTA imaging. The purpose of this revision is to address the current knowledge on pathogenesis, investigations, classification, outcome measures and management, and to emphasize the need for timely diagnosis, effective therapeutic intervention, and close monitoring of this severe condition.