Involvement of Fc gamma receptor polymorphism in the therapeutic response of idiopathic thrombocytopenic purpura.
Clearance of autoantibody-sensitized platelets through Fc gamma receptors on phagocytic cells is one of the main mechanisms of thrombocytopenia in idiopathic thrombocytopenic purpura (ITP). We examined the Fc gamma RIIA-131R/H and Fc gamma RIIIA-158V/F polymorphisms in 104 adult chronic ITP patients, and in 59 healthy control subjects using polymerase chain reaction-based allele-specific restriction analysis. The frequency of Fc gamma RIIA genotypes (131H/H, H/R, R/R) was not significantly different between patients and controls, and did not correlate with the responsiveness to treatment. In contrast, among Fc gamma RIIIA genotypes, frequency of 158F/F homotype was smaller in ITP (P < 0.05). Furthermore, in Fc gamma RIIIA-158V/V homotype, the complete remission (CR) rate with medication (treatment with corticosteroid or other immunosuppressive agents) was significantly higher (60%) than that in 158V/F (10%) or 158V/F plus 158F/F, (P < 0.01, P < 0.05). Conversely, the CR rate after splenectomy in 158F/F and 158V/F types (64.3% and 54.6%) was higher than in 158V/V (25%). Our results indicate that the polymorphism of Fc gamma RIIIA, but not Fc gamma RIIA, influences the response to treatment in ITP.
Fujimoto
T T
TT
Department of Clinical Pharmaceutical Sciences, Graduate School of Medicine, Hiroshima University, Hiroshima, Japan.
Inoue
M
M
Shimomura
T
T
Fujimura
K
K
D000328:Adult; D001323:Autoantibodies / Q000032:analysis; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000276:immunology; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000276:immunology; D016133:Polymerase Chain Reaction / Q000379:methods; D011110:Polymorphism, Genetic; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000276:immunology* / Q000628:therapy; D017452:Receptors, IgG / Q000235:genetics*; D012074:Remission Induction; D012189:Retrospective Studies; D018709:Statistics, Nonparametric
D001323:Autoantibodies; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D019038:Platelet Glycoprotein GPIb-IX Complex; D017452:Receptors, IgG