Background

The Columbia classification is widely used for diagnosis of focal segmental glomerulosclerosis (FSGS). In practice, we occasionally encounter segmental glomerular lesions unclassified as Columbia classification. We analyzed the clinical implication of unclassified segmental lesions comparing with Columbia-classified FSGS.

Methods

A retrospective cohort study from 13 local hospitals in Japan. From 172 biopsy cases diagnosed with FSGS or minimal change disease (MCD)/FSGS spectrum with unclassified segmental lesions, adult patients with nephrotic syndrome who received immunosuppressive therapies were included. The cases are classified by pathology, i.e., typical FSGS lesions sufficiently classified into subgroups of Columbia classification: collapsing (COL), tip (TIP), cellular (CEL), perihilar (PH), and not otherwise specified (NOS), and unclassified by the Columbia classification into three subgroups: “endothelial damage,”; “simple attachment,”; and “minor cellular lesion,”. The response to immunosuppressive treatment and 30% decline of eGFR were compared.

Results

Among 48 eligible cases, all were Japanese, 34 were typical FSGS; 13 TIP, 15 CEL, 6 NOS, and no COL or PH cases. Fourteen were unclassified cases: endothelial damage (n = 6), simple attachment (n = 5), and minor cellular lesion (n = 3). The median age of overall patients was 60 years old and the median of eGFR and urinary protein creatinine ratio was 51.5 mL/min/1.73m² and 7.35, respectively. They received similar therapeutic regimen. Kaplan-Meier analysis revealed no significant difference in treatment response between typical FSGS and unclassified cases. Evaluating among the subgroups, endothelial damage, simple attachment and minor cellular lesion showed similar treatment response to TIP or CEL. No significant difference was also observed in the 30% decline of eGFR.

Conclusions

Japanese adult patients with nephrotic syndrome showing unclassified segmental lesions as Columbia classification may be equivalent clinical impact as Columbia classification of FSGS.

中文翻译：

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局灶性肾小球性肾小球病变的肾病综合征，未按哥伦比亚分类；病理学和临床意义

背景

哥伦比亚分类法广泛用于诊断局灶性节段性肾小球硬化症（FSGS）。在实践中，我们偶尔会遇到未分类为哥伦比亚分类的节段性肾小球病变。我们分析了未分类的节段性病变与哥伦比亚分类的FSGS的临床意义。

方法

来自日本13家当地医院的回顾性队列研究。从172例被诊断为FSGS或最小变化疾病（MCD）/ FSGS频谱，未分类节段性病变的活检病例中，纳入了接受免疫抑制治疗的成年肾病综合征患者。病例按病理学分类，即典型的FSGS病变已充分分类为哥伦比亚分类的亚组：塌陷（COL），尖端（TIP），细胞（CEL），肝门周围（PH），未另作说明（NOS），并且未分类按照哥伦比亚的分类分为三个子组：“内皮损伤”；“简单的附件”；和“小细胞病变”。比较了对免疫抑制治疗的反应和eGFR下降30％。

结果

在48例符合条件的病例中，所有病例均为日本人，其中34例为典型的FSGS。13个提示，15个CEL，6个NOS，并且没有COL或PH案例。14例为未分类病例：内皮损伤（n = 6），单纯附件（n = 5）和轻度细胞病变（n = 3）。总体患者的中位年龄为60岁，eGFR和尿蛋白肌酐比的中位分别为51.5 mL / min / 1.73m ²和7.35。他们接受了类似的治疗方案。Kaplan-Meier分析显示典型FSGS与未分类病例在治疗反应方面无显着差异。在亚组之间评估，内皮损伤，简单附着和轻微细胞病变显示出对TIP或CEL的相似治疗反应。eGFR下降30％也未观察到显着差异。

结论

日本成人肾病综合征患者表现出未分类的节段性病变为哥伦比亚分类，可能与FSGS的哥伦比亚分类具有同等的临床影响。