Sicard Antoine, Karras Alexandre, Goujon Jean-Michel, Sirac Christophe, Bender Sébastien, Labatut Delphine, Callard Patrice, Sarkozy Clémentine, Essig Marie, Vanhille Philippe, Provot François, Nony Alain, Nochy Dominique, Ronco Pierre, Bridoux Frank, Touchard Guy
Néphrologie, Hôpital Européen Georges Pompidou, Paris, France.
Anatomo-Pathologie Rénale, CHU, Poitiers, France Centre de référence amylose AL et autres maladies de dépôt d'immunoglobulines monoclonales.
Nephrol Dial Transplant. 2014 Oct;29(10):1894-902. doi: 10.1093/ndt/gfu045. Epub 2014 Mar 11.
Renal involvement in light chain (LC) deposition disease (LCDD) is typically characterized by nodular glomerulosclerosis and nephrotic range proteinuria. Rare cases of LCDD without glomerular symptoms have been reported, but clinical and pathological characteristics of this entity remain poorly described.
This multi-centre retrospective study included 14 patients with biopsy-proven renal LCDD and proteinuria <0.5 g/day at diagnosis.
Baseline median serum creatinine was 281 (136-594) μmol/L, with a glomerular filtration rate of 20 (6-48) mL/min/1.73 m(2). A serum monoclonal immunoglobulin was detected in 12 cases and LC proteinuria only in 7, always of kappa isotype. Monoclonal gammopathy of undetermined significance/indolent multiple myeloma (MM) was diagnosed in nine cases, symptomatic MM in three cases. Hypertension was almost constant (10 of 14). Immunofluorescence studies of kidney biopsies showed linear kappa LC deposition along tubular basement membranes in all cases, with linear glomerular and vascular LC deposits in 11 and 10 patients, respectively. By light microscopy, tubulo-interstitial lesions were prominent in all patients and focal nodular glomerulosclerosis was only observed in two cases. Identification of LCDD led to initiation of chemotherapy in 12 cases. After a median follow-up of 25.5 months, five patients died and four progressed to end-stage renal disease. Renal response occurred in five of the eight patients who achieved sustained haematological response.
LCDD can cause severe renal dysfunction, despite the absence of glomerular symptoms. Early identification of the disease and introduction of a chemotherapy targeting the underlying plasma cell disorder may preserve long-term renal prognosis.
轻链（LC）沉积病（LCDD）累及肾脏时，其典型特征为结节性肾小球硬化和肾病范围蛋白尿。虽有罕见的无肾小球症状的LCDD病例报道，但该疾病的临床和病理特征仍描述甚少。
这项多中心回顾性研究纳入了14例经活检证实为肾LCDD且诊断时蛋白尿<0.5g/天的患者。
基线时血清肌酐中位数为281（136 - 594）μmol/L，肾小球滤过率为20（6 - 48）mL/min/1.73m²。12例检测到血清单克隆免疫球蛋白，仅7例检测到LC蛋白尿，均为κ型。9例诊断为意义未明的单克隆丙种球蛋白病/惰性多发性骨髓瘤（MM），3例为有症状的MM。高血压几乎普遍存在（14例中有10例）。肾活检的免疫荧光研究显示，所有病例中沿肾小管基底膜均有线性κ轻链沉积，11例和10例患者分别有线性肾小球和血管轻链沉积。光镜下，所有患者肾小管间质病变均很突出，仅2例观察到局灶性结节性肾小球硬化。确诊LCDD后，12例患者开始化疗。中位随访25.5个月后，5例患者死亡，4例进展为终末期肾病。在8例获得持续血液学缓解的患者中，5例出现肾脏缓解。
尽管没有肾小球症状，LCDD仍可导致严重的肾功能不全。早期识别该疾病并引入针对潜在浆细胞疾病的化疗可能改善长期肾脏预后。
