Clinical Significance of Antibodies Against Platelet HLA Class I in Children with Idiopathic Thrombocytopenic Purpura / 대한수혈학회지

ABSTRACT

BACKGROUND: A previous history of transfusion has been known to be associated with production of anti-HLA class I antibodies. However, platelet glycoproteins are the main target of idiopathic thrombocytopenic purpura (ITP). The mechanism of antibody production is known to differ significantly between glycoproteins and anti-HLA class I. The aim of this study was to evaluate the clinical significance of anti-HLA class I antibodies in childhood ITP. METHODS: Enrollment for the normal control group targeted 48 people who visited Gyeongsang National University Hospital from 1990 to 2010, and 48 young children with ITP. Anti-glycoproteins and anti-HLA class I antibodies were tested using the Modified Antigen Capture Enzyme-linked immunosorbent assay (MACE) kit. RESULTS: The positive rate of anti-HLA antibodies was significantly different [36/39 (92.3%) vs 29/46 (63%)] [ITP group vs normal control group] (P=0.002). The mean positive S/C ratio of anti-HLA antibodies was also significantly different (3.55 vs 1.51) [ITP group vs normal control group] (P=0.0000). The positive rate of anti-HLA did not differ significantly between the transfused group and the non-transfused group [12/12 (100%) vs 24/27 (88%)] [transfused ITP vs non-transfused ITP]. The mean positive S/C ratio of anti-HLA antibodies did not differ significantly between the transfused ITP group and the non-transfused ITP group (4.30 vs 3.25) [transfused ITP vs non-transfused ITP]. Consecutive testing showed that positive rate and positive S/C ratio of anti-HLA antibodies did not change significantly between sampling times in both groups [transfused ITP vs non-transfused ITP] (P=1.00 and P=0.15). CONCLUSION: Anti-HLA class I antibodies may be involved in childhood ITP. Transfusion did not affect the course of childhood ITP.