One of the genetic factors associated

with autoimmune diseases is the major histocompatibility complex (MHC). HLA genes are highly polymorphic and encode HLA molecules that are essential for the presentation of foreign antigens to the immune system. The mechanisms underlying MHC association with autoimmune disease are not clearly understood. A breakdown in immunological tolerance to self-antigens through aberrant class II presentation of self or foreign peptides to autoreactive T lymphocytes has been hypothesized. Thus, it seems likely that specific MHC class II alleles determine the targeting of particular autoantigens, resulting in disease-specific associations. Numerous studies have shown significant associations between specific www.selleckchem.com/products/Lapatinib-Ditosylate.html HLA alleles and autoimmune diseases such as diabetes mellitus, rheumatoid arthritis, systemic PLX4032 lupus erythematosus and multiple sclerosis [11–15]. Moreover, an increased susceptibility to inhibitor development in congenital severe haemophilia A was reported to be associated with HLA DRB1*1501 DQA1*0102, DQB1*0602 alleles [16,17]. In this study, we conducted HLA

typing to explore the association of AH with class I HLA-A, HLA-B and HLA-C as well as class II HLA-DRB1 and HLADQB1 loci and compared the results with previous findings for patients with congenital haemophilia A and inhibitors. A cohort of 57 patients with AH admitted to the Haemophilia Centres of Bonn and Frankfurt were included in the study. The diagnosis of AH was confirmed by low FVIII activity (FVIII:C) values (<5%, with a majority of <1%). FVIII:C was measured by a chromogenic assay and a one-stage aPTT based assay. The chromogenic assay was processed on a BCS coagulation analyser (Dade Behring, Eschborn, Germany) medchemexpress using reagents from Siemens Healthcare Diagnostics (Eschborn, Germany). The one-stage assay

is an aPTT based in-house assay processed on a KC10A coagulation analyser (Trinity Biotech, Lemgo, Germany) with FVIII deficient plasma from Helena (UK) distributed by Genzyme Virotech (Rüsselsheim, Germany). FVIII inhibitor activity was determined using the modified Njimegen method [18]. All patients gave informed consent according to the declaration of Helsinki. Total genomic DNA was extracted from EDTA-anticoagulated venous blood by a salting out procedure [19]. MHC Class I (HLA-A, -B, -Cw) and Class II (HLA-DRB1 and -DQB1) typing was carried out using the Dynal RELI™ PCR-SSOP test, following the manufacturer’s recommendations (Dynal Biotech, Wirral, UK). Briefly, the test is based on PCR target amplification (50 and 100 ng of genomic DNA), hybridization of the amplified products to an array of immobilized sequence-specific oligonucleotide probes and detection of the probe-bound amplified product by colorimetric product formation. The SSO probes are designed to hybridize with polymorphic target sequences of the corresponding HLA loci.