Kidney Week

Abstract: PUB337

Untargeted Therapy: A Case of Proliferative Glomerulonephritis with Monoclonal Immunoglobulin A Kappa Deposits

Session Information

• Publication Only

Category: Glomerular Diseases

• 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics

Authors

• Hoang, Victor Dang, Brooke Army Medical Center, Fort Sam Houston, Texas, United States

Victor Dang Hoang, DO

• Sevilla Rodriguez, Javier Francisco, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States

Javier Francisco Sevilla Rodriguez, MD

• Gilani, Sarwat, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States

Sarwat Gilani, MBBS

• Musa, John Louis, Audie L Murphy Memorial Veterans' Hospital, San Antonio, Texas, United States

John Louis Musa, MD

Introduction

Proliferative glomerulonephritis with monoclonal immunoglobulin deposits (PGNMID) is a rare disorder, and the majority of affected patients do not have a detectable plasma/B-cell clone. This complicates management, and current therapy is based on data from small cohorts.

Case Description

A 77-year-old male presented with 2 weeks of melena and new bilateral lower extremity pitting edema. His labs were notable for serum creatinine of 1.5 mg/dL from a baseline of 1.2 mg/dL, and hemoglobin of 8.7 g/dL. Urinalysis was notable for 3+ protein and moderate blood with no cellular casts. Urine protein-creatinine ratio was 8.3. Extensive serologic workup was unremarkable. SPEP noted possible monoclonal spike in gamma region, which may be free kappa light chain measuring 0.1 g/dL. Renal biopsy demonstrated focal endocapillary proliferative and crescentic glomerulonephritis with IgA kappa restricted deposits (Figure 1). Hematology was consulted. Bone marrow biopsy noted no abnormal lymphocyte population and 0.6% polyclonal plasma cells. After inter-disciplinary discussion and risk/benefit discussion with the patient, therapy was initiated with bortezomib, cyclophosphamide, and dexamethasone.

Discussion

This case demonstrates the multi-disciplinary approach required to effectively treat cases of PGNMID. Specifically in cases where no plasma cell clone is found, there is still debate on ideal therapy.

Focal endocapillary proliferative glomerulonephritis (A) with infiltrating mononuclear cells of histiocytic lineage highlighted by CD68 stain (B). Frozen immunofluorescence studies show IgA (C) and kappa light chain (D) restricted deposits that are negative for lambda light chain (E). Electron micrograph shows mesangial deposits with no substructures (F).