# Rapidly Progressive Glomerulonephritis Secondary to Immunoglobulin M-associated Monoclonal Gammopathy of Renal Significance: A Report of a Rare Case

## TL;DR

This paper reports a rare case of kidney disease caused by a specific type of monoclonal gammopathy, emphasizing the diagnostic challenges and clinical implications.

## Contribution

The novelty lies in presenting a rare case of IgM-associated MGRS manifesting as rapidly progressive glomerulonephritis.

## Key findings

- IgM-associated monoclonal gammopathy can lead to rapidly progressive glomerulonephritis.
- MGUS is often undiagnosed due to its asymptomatic nature and overlap with age-related conditions.
- MGUS can cause significant renal complications such as MGRS.

## Abstract

Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant condition characterized by monoclonal paraprotein production, with IgM and non-IgM variants. While IgM MGUS is often associated with lymphoid neoplasms, non-IgM MGUS can progress to multiple myeloma. Comorbidities include bone mineral density loss and renal complications, such as monoclonal gammopathy of renal significance (MGRS) and peripheral neuropathy. Cardiovascular risks are also elevated. Despite its significance, MGUS often goes undiagnosed due to its asymptomatic nature and overlap with age-related comorbidities. We present a case of IgM MGRS manifesting as rapidly progressive glomerulonephritis, highlighting the diagnostic challenges and clinical implications of MGUS-associated complications.