Lack of association between macrophage migration inhibitory factor gene (-173 G/C) polymorphism and cutaneous vasculitis

To assess whether polymorphism of the macrophage migration inhibitory factor (MIF) gene at position -173 was implicated in the incidence of Henoch-Schönlein purpura (HSP) and cutaneous leukocytoclastic angiitis (CLA). A further objective was to determine if any relationship existed with severe systemic complications of HSP, in particular with severe renal involvement and permanent renal dysfunction.Unselected patients from Northwest Spain with primary cutaneous vasculitis classified as HSP or hypersensitivity vasculitis (HV) according to proposed criteria were studied. Patients with HV were included in this study if they fulfilled the Chapel Hill Consensus Conference on the Nomenclature of Systemic Vasculitis definitions for CLA. Patients and controls were genotyped for a single nucleotide polymorphism (SNP) in the 5'-flanking region at position -173 of the MIF gene, using SNapshot ddNTP primer extension, followed by capillary electrophoresis (ABI 3100).Ninety-five Caucasian patients (57 classified as having HSP and 38 who fulfilled definitions for CLA) and 122 healthy controls were studied. No allele or genotype differences between the whole group of HSP or CLA patients and controls were observed. This was also the case when HSP patients were stratified by the presence of gastrointestinal complications, nephritis, and permanent renal involvement (renal sequelae).The polymorphism in MIF gene promoter (-173 G/C) does not appear to be genetic risk factors for cutaneous vasculitis in Northwest Spain.