HLA frequencies and haplotypes in children with idiopathic thrombocytopenic purpura (ITP)

Abstract

26 patients with an acute reversible ITP and 6 with chronic ITP were tissue typed, together with their healthy first-degree relatives. The HLA frequencies of the different groups were compared with those of a normal control population. The only significant difference between the groups was an increase in the frequency of Aw32 in acute ITP patients. HLA-Aw32 was present in 26.9% of patients, but in only 0.8% of the controls (corrected P = 0.000027). The possible importance of associations between antigens of the HLA-A locus with certain diseases are discussed. Family analyses and haplotype determinations proved to be unproductive because no familial clustering of ITP was found.

HLA Antigens, Blood Groups and Immunoglobulin Levels in Idiopathic Thrombocytopenic Purpura

“…The observed high frequency of HLA-A28 could be explained by chance; a similar observation has been reported [12], however. Our results do not confirm the previously reported increased incidence of HLA antigens HLA-B8, B12 [11], BW38 [12] and AW23 [19]. This may be due to regional differences in HLA frequencies or sampling error.…”

MHC Class I–Associated Peptides Identified From Normal Platelets and From Individuals With Idiopathic Thrombocytopenic Purpura

“…In addition, the sample population for some of these studies was limited. Select studies that reported no HLA association with ITP found an HLA allele increased in the ITP population; however, when a correction of the p value for the number of antigens tested was done, the results became insignificant [12,16,19]. Therefore, a particular HLA allele may or may not be linked to ITP.…”

“…HLA alleles found to be associated with ITP include HLA-B8 and -B12 in adult patients with chronic ITP [11], Aw32 in children with acute ITP [12], and HLA-A28 in chronic ITP patients [13]. The presence of HLA-DRw2 was also significantly increased in ITP patients along with the co-occurrence of either A3 and B7 (known to be in linkage disequilibrium with DRw2) or A26 and Bw38 [14].…”

Lack of association between HLA specificities and Wilm's tumour

“…There is general agreement that associations between HLA antigens and nonmalignant diseases are due to the presence in the HLA complex of a susceptibility gene for a special disease in linkage disequilibrium with some HLA markers [5]. Striking associations with certain HLA antigens have especially been shown for diseases with immunopathogenic components [6,12,14]. For malignant diseases such associations, though extensively studied, are very rare.…”