Immunotactoid Glomerulopathy Diagnosed by a Repeat Kidney Biopsy After Initially Non-diagnostic Electron Microscopic Findings: A Case Report
Abstract
Immunotactoid glomerulopathy (ITG) is diagnosed by identifying organized microtubules on electron microscopy and it can therefore be missed when they are not demonstrated. A 48-year-old woman with hematuria, nephrotic-range proteinuria, and a faint IgG-κ monoclonal protein underwent an initial kidney biopsy, which showed endocapillary proliferative glomerulonephritis with membranoproliferative features and scant subendothelial deposits, but no diagnostic microtubules. With worsening renal dysfunction and a limited corticosteroid response, a repeat biopsy revealed IgG3-κ-restricted deposits and non-branching, hollow-core microtubules, confirming ITG associated with monoclonal gammopathy of renal significance. Rituximab-based B cell-directed therapy was followed by sustained remission with prednisolone tapered to 2.5 mg every other day.
Related
- RUNX1 Familial Platelet Disorder with Associated Myeloid Malignancies Initially Diagnosed as Immune Thrombocytopenia and Reclassified After 10 Years: Diagnostic Pitfall Revealed by a Family History
- Pararectal Leiomyosarcoma Following Total Laparoscopic Hysterectomy (TLH) for Initially Diagnosed Uterine Leiomyoma
- A Diagnostic Approach to Giant Cell Arteritis Initially Presenting with Infarction without Headache Using MR Vessel Wall Imaging and a Temporal Artery Biopsy: A Case Report
- Probable Seronegative Myasthenia Gravis With Initially Negative Diagnostic Testing: A Case Report
- Symptomatic Elastofibroma Dorsi Initially Presumed to Be a Subscapular Lipoma: Diagnostic Clues From Dynamic Ultrasonography and Intraoperative Findings.
BibTeX
@article{yamada2026immunotactoid,
title = {{Immunotactoid Glomerulopathy Diagnosed by a Repeat Kidney Biopsy After Initially Non-diagnostic Electron Microscopic Findings: A Case Report}},
author = {Muneharu Yamada and Masataka Nagashima and Ken Aoki and Takahiko Hoshino and Rie Fujii and Takahiro Uchida and Yutaka Yamaguchi and Takashi Oda},
journal = {Internal Medicine},
year = {2026},
month = sep,
doi = {10.2169/internalmedicine.8178-26},
url = {https://www.jstage.jst.go.jp/article/internalmedicine/advpub/0/advpub_8178-26/_article},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Immunotactoid Glomerulopathy Diagnosed by a Repeat Kidney Biopsy After Initially Non-diagnostic Electron Microscopic Findings: A Case Report
AU - Muneharu Yamada
AU - Masataka Nagashima
AU - Ken Aoki
AU - Takahiko Hoshino
AU - Rie Fujii
AU - Takahiro Uchida
AU - Yutaka Yamaguchi
AU - Takashi Oda
PY - 2026
DA - 2026/09/08
JO - Internal Medicine
DO - 10.2169/internalmedicine.8178-26
UR - https://www.jstage.jst.go.jp/article/internalmedicine/advpub/0/advpub_8178-26/_article
AB - Immunotactoid glomerulopathy (ITG) is diagnosed by identifying organized microtubules on electron microscopy and it can therefore be missed when they are not demonstrated. A 48-year-old woman with hematuria, nephrotic-range proteinuria, and a faint IgG-κ monoclonal protein underwent an initial kidney biopsy, which showed endocapillary proliferative glomerulonephritis with membranoproliferative features and scant subendothelial deposits, but no diagnostic microtubules. With worsening renal dysfunction and a limited corticosteroid response, a repeat biopsy revealed IgG3-κ-restricted deposits and non-branching, hollow-core microtubules, confirming ITG associated with monoclonal gammopathy of renal significance. Rituximab-based B cell-directed therapy was followed by sustained remission with prednisolone tapered to 2.5 mg every other day.
SN - 1349-7235
SN - 0918-2918
ER -