Nagae Hiroshi, Tsuchimoto Akihiro, Tsuruya Kazuhiko, Kawahara Shota, Shimomura Yukiko, Noguchi Hideko, Masutani Kosuke, Katafuchi Ritsuko, Kitazono Takanari
Kidney Unit, National Fukuoka-Higashi Medical Center, Chidori, Koga, Fukuoka, 811-3113, Japan.
Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Clin Exp Nephrol. 2017 Apr;21(2):266-274. doi: 10.1007/s10157-016-1275-7. Epub 2016 May 12.
Clinicopathological significance of monoclonal IgA deposition and its relation to bone marrow abnormalities in IgA nephropathy (IgAN) remains unclear.
We retrospectively investigated the prevalence and clinicopathological significance of monoclonal IgA deposition in 65 patients with IgAN. Serum-free light chain ratio, and urinary Bence Jones protein were also measured.
Thirty-nine percent of patients were men, median age was 40 and median observation period was 31 months. Five patients (Group M) showed monoclonal IgA lambda deposition and one showed monoclonal IgA kappa deposition. Fifty-nine patients (Group P) showed polyclonal IgA deposition. There were no significant differences in the degree of proteinuria, hematuria and renal function between Group M and Group P. Total protein and albumin were significantly lower in Group M than in Group P. According to the Oxford classification, the percentage of patients with M1 was significantly higher in Group M than in Group P. One patient in Group P showed serum monoclonal IgG lambda. No patient showed abnormal serum-free light chain ratio. Seventy-five percent in Group M and 42 % in Group P were treated with steroid. Three patients in Group P progressed to end-stage renal disease (ESRD). The frequency of disappearance of proteinuria or hematuria and progression to ESRD was not different between the groups.
The prevalence of monoclonal IgA deposition was 9.2 %. Although some parameters differed between the groups, renal outcome were similar. Thus, IgAN with monoclonal IgA deposition seems not to be different entity from those with polyclonal IgA deposition.
IgA肾病（IgAN）中，单克隆IgA沉积的临床病理意义及其与骨髓异常的关系尚不清楚。
我们回顾性调查了65例IgAN患者中单克隆IgA沉积的患病率及其临床病理意义。还检测了血清游离轻链比值和尿本周蛋白。
患者中39%为男性，中位年龄40岁，中位观察期31个月。5例患者（M组）出现单克隆IgA λ沉积，1例出现单克隆IgA κ沉积。59例患者（P组）出现多克隆IgA沉积。M组和P组在蛋白尿、血尿程度及肾功能方面无显著差异。M组总蛋白和白蛋白显著低于P组。根据牛津分类，M组M1患者的百分比显著高于P组。P组1例患者出现血清单克隆IgG λ。无患者血清游离轻链比值异常。M组75%和P组42%接受了类固醇治疗。P组3例患者进展至终末期肾病（ESRD）。两组间蛋白尿或血尿消失频率及进展至ESRD的情况无差异。
单克隆IgA沉积的患病率为9.2%。尽管两组间一些参数不同，但肾脏预后相似。因此，有单克隆IgA沉积的IgAN似乎与有多克隆IgA沉积的IgAN并非不同的疾病实体。
