Ellithy Hend N, Ahmed Salwa H, Shahin Gehan H, Matter Mervat M, Talatt Mohamed
a Clinical Hematology Unit - Internal Medicine Department, Faculty of Medicine , Cairo University , Cairo , Egypt.
b Clinical Pathology Department, Faculty of Medicine , Cairo University , Cairo , Egypt.
Hematology. 2018 Apr;23(3):169-174. doi: 10.1080/10245332.2017.1371479. Epub 2017 Aug 31.
Background In chronic immune thrombocytopenic purpura (ITP), rituximab removes the harmful autoantibodies through antibody-dependent cellular cytotoxicity. The response to rituximab in ITP is variable; the effectiveness of rituximab is influenced by the process of activation of effector fragment C gamma receptors (FcγRs). Genetic factors may affect the response to rituximab. Objectives The influence of FcγRIIa (H131R) and FcγRIIIa (V158F) gene polymorphisms on the response to rituximab in ITP. Methods One hundred ITP patients were genotyped for FcγRIIa (H131R) and FcγRIIIa (V158F) gene polymorphisms using the polymerase chain reaction-restriction fragment length polymorphism assay. The response at the end of the third month was assessed by direct platelets count. Polymorphisms were analyzed in relation to the response. Results The mean platelets count at end of weeks 1-4 of rituximab was statistically significantly higher in patients who achieved complete response (CR) than partial response or no response (P-value = .001). Although RR (44.4%) and HR (38.9%) genotypes were observed to be higher in patients who achieved CR compared with the wild (HH) genotype (16.7%), it was not statistically significantly different (P-value = .648). Conclusion The higher platelet count achieved early is predictive for a better response to rituximab later. FCγRIIA polymorphisms did not significantly influence response to rituximab in ITP.
背景 在慢性免疫性血小板减少性紫癜（ITP）中，利妥昔单抗通过抗体依赖性细胞毒性作用清除有害自身抗体。ITP患者对利妥昔单抗的反应存在差异；利妥昔单抗的疗效受效应片段Cγ受体（FcγRs）激活过程的影响。遗传因素可能影响对利妥昔单抗的反应。目的 FcγRIIa（H131R）和FcγRIIIa（V158F）基因多态性对ITP患者利妥昔单抗反应的影响。方法 采用聚合酶链反应-限制性片段长度多态性分析对100例ITP患者的FcγRIIa（H131R）和FcγRIIIa（V158F）基因多态性进行基因分型。通过直接血小板计数评估第三个月末的反应。分析多态性与反应的关系。结果 达到完全缓解（CR）的患者在利妥昔单抗治疗第1 - 4周结束时的平均血小板计数显著高于部分缓解或无反应患者（P值 = 0.001）。虽然达到CR的患者中RR（44.4%）和HR（38.9%）基因型高于野生型（HH）基因型（16.7%），但差异无统计学意义（P值 = 0.648）。结论 早期获得较高的血小板计数可预测后期对利妥昔单抗有更好的反应。FCγRIIA基因多态性对ITP患者利妥昔单抗反应无显著影响。
