Ravipati Prasanth, Freese Rebecca L, Royal Virginie, Bu Lihong, Canetta Pietro, Gipson Debbie, Kallash Mahmood, Kiryluk Krzysztof, Nast Cynthia, Reich Heather N, Rheault Michelle N, Saha Manish, Nachman Patrick H
Division of Nephrology and Hypertension, Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA.
Division of Nephrology, Department of Medicine, University of Nebraska, Omaha, Nebraska, USA.
Kidney Int Rep. 2022 Aug 17;7(11):2462-2473. doi: 10.1016/j.ekir.2022.08.003. eCollection 2022 Nov.
IgA nephropathy (IgAN) differs from other glomerular diseases by the frequently predominant lambda over kappa light chain deposition. Using the Cure Glomerulonephropathy (CureGN) IgAN cohort, we aimed to determine whether predominant lambda chain deposition is associated with worse clinical outcomes or histopathologic markers of more active disease.
Patients were categorized based on the intensity of light chain staining. The lambda dominant (LD) group was defined by a difference in intensity score of lambda minus kappa ≥ 1+ and the kappa-lambda codominant (KL) group by a difference < 1+. We compared the clinical course of patients in each category from the time of kidney biopsy and time of enrollment into CureGN to the time of remission (proteinuria < 0.3 g/g), 50% reduction in estimated glomerular filtration rate (eGFR), or progression to end-stage kidney disease (ESKD). We also analyzed differences in histopathologic characteristics between the 2 groups.
Among 440 patients, we found no significant differences between groups in baseline clinical characteristics nor in rates of remission, 50% reduction in eGFR, or progression to ESKD. Patients in the LD group had a modestly greater frequency of IgG staining ≥ 1+. The biopsy results of 234 patients reviewed by CureGN pathologists revealed a greater frequency of endocapillary hypercellularity (51.1% vs. 36.3%, = 0.04) in the LD group, but no other significant difference in histopathologic features.
In IgAN, we found an association between lambda predominance and increased endocapillary hypercellularity, but no association with clinical outcomes.
IgA 肾病（IgAN）与其他肾小球疾病的不同之处在于，其轻链沉积通常以 λ 链为主，而非 κ 链。我们利用 Cure 肾小球肾病（CureGN）IgAN 队列，旨在确定 λ 链为主的沉积是否与更差的临床结局或疾病活动度更高的组织病理学标志物相关。
根据轻链染色强度对患者进行分类。λ 链为主（LD）组定义为 λ 链强度评分减去 κ 链强度评分≥1+，κ-λ 共显性（KL）组定义为差值<1+。我们比较了每组患者从肾活检时和纳入 CureGN 时到缓解（蛋白尿<0.3 g/g）、估计肾小球滤过率（eGFR）降低 50%或进展至终末期肾病（ESKD）的临床病程。我们还分析了两组之间组织病理学特征的差异。
在 440 例患者中，我们发现两组在基线临床特征、缓解率、eGFR 降低 50%或进展至 ESKD 的发生率方面均无显著差异。LD 组中 IgG 染色≥1+的频率略高。CureGN 病理学家复查的 234 例患者的活检结果显示，LD 组的毛细血管内细胞增多症发生率更高（51.1%对 36.3%，P = 0.04），但在组织病理学特征方面无其他显著差异。
在 IgAN 中，我们发现 λ 链为主与毛细血管内细胞增多症增加有关，但与临床结局无关。
