The first genome-wide association study GWAS of IgA vasculitis

26 de July de 2017

The first genome-wide association study (GWAS) in IgA vasculitis worldwide has been conducted by the research group of IDIVAL “Genetic epidemiology and atherosclerosis in systemic inflammatory diseases”, led by Dr. Miguel Ángel González-Gay, in collaboration with other Hospitals and national and international Institutes. 

Immunoglobulin-A (IgA) vasculitis, also known as Henoch-Schöenlein purpura (HSP), is the most common type of primary small-sized blood vessel leukocytoclastic vasculitis in children, although it may also develop in adults. Although the classic clinical triad of IgA vasculitis consists of palpable purpura (involving the lower extremities), joints and the gastrointestinal tract, renal complications may also develop in affected individuals. In this regard, the outcome of IgA vasculitis patients is related to the presence of glomerulonephritis, which may lead to chronic renal failure. IgA vasculitis has a multifactorial etiology in which both environmental and genetic factors seem to contribute to the predisposition and clinical phenotype of the disease. However, the genetic component of this type of vasculitis remains poorly understood, as only a few candidate gene studies have been performed to date.

This study aimed at conducting the first GWAS of IgA vasculitis using the largest series of IgA vasculitis patients in which numerous National Hospitals participated. To achieve this goal, 308 IgA vasculitis patients (currently the largest cohort of patients with this disease for genetic studies) and 1,018 healthy controls from Spain were genotyped. 

The results suggest the involvement of HLA class II region in the pathophysiology of IgA vasculitis, thus supporting the high relevance of the immune system in the development of this disease and suggesting that IgA vasculitis may be related to other class II vasculitides such as giant cell arteritis and antineutrophil cytoplasmic antibody (ANCA).

López-Mejías R, Carmona FD, Castañeda S, Genre F, Remuzgo-Martínez S, Sevilla-Perez B, Ortego-Centeno N, Llorca J, Ubilla B, Mijares V, Pina T, Miranda-Filloy JA, Navas Parejo A, de Argila D, Aragües M, Rubio E, Luque ML, Blanco-Madrigal JM, Galíndez-Aguirregoikoa E, Jayne D, Blanco R, Martín J, González-Gay MA. A genome-wide association study suggests the HLA Class II region as the major susceptibility locus for IgA vasculitis. Sci Rep. 2017 Jul 11;7(1):5088. doi: 10.1038/s41598-017-03915-2.