HNA specificity and association to HLA-DRB1 and -DQB1 in patients with autoimmune neutropenia of early childhood

Autoimmune neutropenia (AIN) of early childhood is caused by autoantibodies against antigens on the neutrophil membrane. Human leukocyte (HLA) have previously been associated with AIN. This study investigated HLA-DRB1 and HLA-DQB1 alleles in 160 antibody positive patients compared 1000 controls. Increased risk was observed for DRB1*10, DRB1*14, DRB1*16 DQB1*05, lower DRB1*04, DRB1*13 DQB1*03. Haplotypes higher included: DRB1*10/DQB1*05, DRB1*14/DQB1*05 DRB1*16/DQB1*05, while DRB1*04/DQB1*03, DRB1*07/DQB1*02, DRB1*13/DQB1*06 were risk. Associated –DQB1 differed between anti-HNA-1a-specific antibodies broad reactive anti-FcγRIIIb antibodies. DRB1*01, DRB1*04 DQB1*03 only anti-HNA-1a positive, DRB1*10 restricted to positive. Strong association AIN -DQB1 haplotypes suggested that they play a role susceptibility or protection. Different associations regarding FcγRIIIb specificities could indicate disease heterogeneity.