单克隆B淋巴细胞增多伴肾功能不全

B cell chronic lymphoproliferative disease and chronic kidney disease

57岁男性,因血压升高伴肾功能减退2年入院,病程中体重减轻5 kg,脾大,外周血淋巴细胞增多,CD20+1420个/μl.骨髓流式细胞检测:淋巴细胞占有核细胞36.5%,其中B细胞占淋巴细胞78%,表达HLA-DR、CD5、CD19、CD20、CD22、sKappa(dim),lammda阴性.肾活检提示肾小球膜增生性病变伴单一IgG3沉积、肾间质多灶性CD20+细胞浸润,最终诊断为膜增生性肾小球肾炎伴单克隆IgG沉积、B细胞慢性淋巴增殖性疾病-不能分类,予以利妥昔单抗治疗,随访13个月,血清肌酐、尿蛋白下降.对于病因不明的增生性肾炎伴持续性淋巴细胞增多者,需排除B细胞慢性淋巴增殖性疾病.

A 57⁃year⁃old man was admitted to the hospital with hypertension and renal hypofunction for 2 years.During the course of the disease,he lost 5 kg of body weight,splenomegaly and increased peripheral blood lymphocytes.Bone marrow flow cytometry showed that lymphocytes accounted for 36􀆱5%of nuclear cells,of which B cells accounted for 78%,expressing HLA⁃DR,CD5,CD19,CD20,CD22,sKappa(dim)and negative for lammda.Renal biopsy revealed glomerular proliferative lesions with single IgG3 deposition and multifocal interstitial infiltration of CD20 positive cells.The final diagnosis was membranous proliferative glomerulonephritis with monoclonal IgG3 deposition and B⁃cell chronic lymphoproliferative disease.After treatment with Rituximab for 13 months,serum creatinine and urinary protein decreased.This is the first case of membranoproliferative nephritis caused by B lymphocyte proliferative disease reported in China.For proliferative glomerulonephritis with persistent lymphocytosis of unknown etiology,B cell chronic lymphoproliferative disease should be excluded.