Involvement of Fcγ receptor polymorphism in the therapeutic response of idiopathic thrombocytopenic purpura

• Published in: British journal of haematology Vol. 115; no. 1; pp. 125 - 130
• Main Authors: Fujimoto, Tetsuro‐Takahiro, Inoue, Maki, Shimomura, Takeshi, Fujimura, Kingo
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.10.2001; Blackwell
• Subjects: Adult; Autoantibodies - analysis; Biological and medical sciences; Case-Control Studies; Chi-Square Distribution; FcγIIA; FcγIIIA; Female; Genotype; Hematologic and hematopoietic diseases; Humans; ITP; Male; Medical sciences; Middle Aged; Patient Selection; Platelet diseases and coagulopathies; Platelet Glycoprotein GPIb-IX Complex - immunology; Platelet Glycoprotein GPIIb-IIIa Complex - immunology; Polymerase Chain Reaction - methods; polymorphism; Polymorphism, Genetic; Purpura, Thrombocytopenic, Idiopathic - immunology; Purpura, Thrombocytopenic, Idiopathic - therapy; Receptors, IgG - genetics; Remission Induction; Retrospective Studies; Statistics, Nonparametric; therapeutic response; Human; Thrombocytopenia; Immunopathology; Prognosis; Treatment efficiency; FcγRIIIA receptor; Immunoglobulin receptor; Hemopathy; FcγR receptor; FcγRIIA receptor; Platelet; Gene; Immune thrombocytopenic purpura; Polymorphism
• ISSN: 0007-1048; 1365-2141
• DOI: 10.1046/j.1365-2141.2001.03109.x

Clearance of autoantibody‐sensitized platelets through Fcγ receptors on phagocytic cells is one of the main mechanisms of thrombocytopenia in idiopathic thrombocytopenic purpura (ITP). We examined the FcγRIIA‐131R/H and FcγRIIIA‐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 FcγRIIA 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 FcγRIIIA genotypes, frequency of 158F/F homotype was smaller in ITP (P < 0·05). Furthermore, in FcγRIIIA‐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 FcγRIIIA, but not FcγRIIA, influences the response to treatment in ITP.