Departments of Nephrology.
Pathology, West China Hospital, Sichuan University, Chengdu, China.
Am J Med Sci. 2018 Oct;356(4):365-373. doi: 10.1016/j.amjms.2018.07.001. Epub 2018 Jul 7.
Glomerular immunoglobulin M (IgM) deposition is common in diabetic kidney disease. The clinical implication of IgM deposition in the renal tissues of type 2 diabetes mellitus patients with biopsy-proven diabetic nephropathy remains unclear.
One hundred thirty-two patients with type 2 diabetes and biopsy-proven pure diabetic nephropathy were enrolled retrospectively. Clinicopathological features and renal outcomes were compared between patients with and without glomerular capillary IgM deposition. A Cox proportional hazards model was employed to identify the risk factors associated with renal survival.
Fifty-two patients had positive linear glomerular capillary IgM staining. Patients with glomerular capillary IgM deposition presented with heavier proteinuria, and lower serum albumin. During 35.5 (12, 107) months of follow-up, patients with glomerular tuft IgM deposition had shorter renal survival than those with negative IgM deposition (39 [23.74, 54.26] versus (vs.) 64 [45.82, 82.18] months, P = 0.01). Patients with glomerular complement 1q (C1q) deposition showed worse renal survival than those lacking glomerular C1q deposition (36 [23.82, 48.18] vs. 60 [50.27, 69.74] months, P = 0.001). Worse renal outcome was observed in patients with glomerular C3 deposition than in those without glomerular C3 deposition (37 [22.43, 51.56] vs. 63 [51.75, 74.25] months, P = 0.001). Multivariate Cox proportional analysis demonstrated that combined glomerular capillary IgM and C1q deposition was an independent predictor of end-stage renal disease (hazard ratio 3.75, 95% CI[ 1.68,8.35], P = 0.001).
Patients with diabetic nephropathy and combined glomerular capillary IgM and C1q deposition had unfavorable renal outcome, which indicates that IgM derived from B cells might be involved in diabetic kidney injury.
肾小球免疫球蛋白 M（IgM）沉积在糖尿病肾病中很常见。在经活检证实为糖尿病肾病的 2 型糖尿病患者的肾组织中，IgM 沉积的临床意义尚不清楚。
回顾性纳入 132 例经活检证实为 2 型糖尿病合并纯糖尿病肾病的患者。比较有和无肾小球毛细血管 IgM 沉积的患者的临床病理特征和肾脏结局。采用 Cox 比例风险模型确定与肾脏生存相关的危险因素。
52 例患者的肾小球毛细血管 IgM 呈线性染色阳性。有肾小球毛细血管 IgM 沉积的患者蛋白尿更重，血清白蛋白更低。在 35.5（12，107）个月的随访中，有肾小球球丛 IgM 沉积的患者肾脏生存时间短于无 IgM 沉积的患者（39 [23.74，54.26]与 64 [45.82，82.18]个月，P=0.01）。有肾小球补体 1q（C1q）沉积的患者肾脏生存较无肾小球 C1q 沉积的患者差（36 [23.82，48.18]与 60 [50.27，69.74]个月，P=0.001）。有肾小球 C3 沉积的患者肾脏结局较无肾小球 C3 沉积的患者差（37 [22.43，51.56]与 63 [51.75，74.25]个月，P=0.001）。多变量 Cox 比例风险分析表明，肾小球毛细血管 IgM 和 C1q 联合沉积是终末期肾脏疾病的独立预测因素（风险比 3.75，95%CI[1.68，8.35]，P=0.001）。
伴有肾小球毛细血管 IgM 和 C1q 联合沉积的糖尿病肾病患者肾脏预后不良，这表明 B 细胞来源的 IgM 可能参与了糖尿病肾损伤。
