Published in:
01-04-2012 | Original Article
The role of human leukocyte antigens as predisposing and/or protective factors in patients with idiopathic thrombotic thrombocytopenic purpura
Authors:
Marie-Luise John, Walter Hitzler, Inge Scharrer
Published in:
Annals of Hematology
|
Issue 4/2012
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Abstract
Fifty-four adult German patients suffering from idiopathic thrombotic thrombocytopenic purpura (TTP) have been examined for HLA class II. All patients presented autoantibodies against ADAMTS13 and ADAMTS13 activity levels <5%. Blood samples have been analyzed for HLA-DRB1 and DQB1 alleles using sequence-specific primer PCR and sequence-specific oligonucleotide PCR. Reference data of German bone marrow and blood donors were obtained from
www.allelefrequencies.net. The results were evaluated employing two-sided binomial tests, and
p values were corrected using the Benjamini–Hochberg procedure. A significant accumulation for DQB1*02:02 (
p < 0.001) and DRB1*11 (
p = 0.003) was found within the patient group. Twenty percent (DQB1*02:02) or 48.1% (DRB1*11) of TTP patients were tested positive for the particular HLA antigen compared to 1.2% (DQB1*02:02) or 23.5% (DRB1*11) in the control group. A tendency for a reduced occurrence of HLA-DRB1*04 was revealed (7.4% in patients compared to 24.6% in controls). An association between the HLA antigens DQB1*02:02 and DRB1*11 and disease susceptibility for idiopathic TTP has been found. A higher risk for disease outbreak within persons carrying the mentioned alleles can be assumed. The reduced occurrence of HLA-DRB1*04 in TTP patients indicates a possible protective effect of this HLA allele in disease development.