Analysis of renal pathological misdiagnosis in 15 patients with light chain amyloidosis
10.3760/cma.j.cn441217-20240126-00133
- VernacularTitle:15例轻链型淀粉样变性患者肾组织病理误诊分析
- Author:
Xin ZHANG
1
;
Xiaojuan YU
;
Jin XU
;
Minghui ZHAO
;
Suxia WANG
;
Fude ZHOU
Author Information
1. 北京大学第一医院肾内科 北京大学肾脏疾病研究所，北京 100034
- Keywords:
Amyloidosis;
Diagnostic errors;
Pathology;
Monoclonal gammopathy with renal significance
- From:
Chinese Journal of Nephrology
2024;40(9):716-722
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To analyze the clinical and pathological data of 15 patients with light chain amyloidosis initially diagnosed with other kidney diseases, and identify possible misdiagnosis reasons.Methods:It was a retrospective observational study. The clinical and pathological data of 15 patients, whose initial kidney biopsies failed to diagnose light chain-amyloidosis but were confirmed by a subsequent kidney biopsy or pathology consultation at Peking University First Hospital from January 2010 to December 2022 were collected. The results of immunofluorescence, Congo red staining, and electron microscopy of two renal biopsies were analyzed.Results:The median age of 15 patients was 56 years old, with a male-to-female ratio of 7∶8. The main clinical manifestation was massive proteinuria with normal kidney function, and there were 10 cases presenting as nephrotic syndrome. The initial diagnosis based on the first kidney biopsy included minimal change disease (8 cases), IgA nephropathy (3 cases), membranous nephropathy (3 cases), and type Ⅲ collagen glomerulonephritis (1 case). M proteinemia was not evaluated in 13 patients during the first kidney biopsy. Light chain immunofluorescence staining was not performed in 12 cases. Congo red staining was not performed in 13 cases. All fifteen patients received glucocorticoids combined with immunosuppressive therapy after their initial diagnosis, and 5 patients developed severe infection. After 12.0 (7.5, 20.0) months of treatment, none of them achieved clinical remission. Thirteen had evidences for M protein before the second kidney biopsy. The renal tissues of all patients underwent immunofluorescence light chain examination, Congo red staining, and immunoelectron microscopy examination when necessary. The repeat kidney biopsies of 14 cases and pathology consultation of one case consistently indicated light chain-amyloidosis. The kidney tissues in 13 cases were confirmed to be light chain restricted, 11 cases by immunofluorescence, and 2 cases by immune electron microscopy. After diagnosis of light chain-amyloidosis, all patients received targeted plasma cell therapy except for 1 patient lost to follow-up, 6 patients achieved hematologic remission, 5 patients achieved renal remission, 1 patient entered end-stage renal disease, and 3 patients died.Conclusions:In middle and elderly-aged patients with nephrotic syndrome, if conventional immunosuppressive therapy yields unsatisfactory results, it is crucial to focus on identifying evidences of monoclonal immunoglobulinemia, if necessary, kidney biopsy should be actively repeated. Kidney biopsy pathology should include comprehensive examinations such as light chain immunofluorescence, Congo red staining, and electron microscopy to avoid misdiagnosis of light chain-amyloidosis.
