Abstract: TH-PO190

An Unexpected Finding of Post Infectious Glomerulonephritis Superimposed on Cryoglobulin Mediated Membranoproliferative Glomerulonephritis in a Patient with Influenza

Session Information

Category: Nephrology Education

  • 1302 Fellows and Residents Case Reports

Authors

  • Syeda, Sara, Brown University , Providence, Rhode Island, United States
  • Tang, Jie, Brown University , Providence, Rhode Island, United States
Background

Active glomerulonephritis with hypocomplementemia has a limited differential. Here we present an interesting case of acute kidney injury (AKI) with influenza, in which kidney biopsy showed cryoglobulinemic membranoproliferative glomerulonephritis (MPGN) and evidence of post-infectious glomerulonephritis (PIGN).

Methods

A 62-year-old man with history of clinically inactive low-grade B cell lymphoma (LGBL), presented with cough, myalgias, and tested positive for Influenza A. He was found to have AKI with a serum creatinine of 11.9mg/dL (baseline 1.1mg/dL), sub-nephrotic proteinuria and microscopic hematuria. Serologic studies showed low complements (C3, C4) and a weak monoclonal IgG lambda light chain on serum electrophoresis. All other infectious and rheumatologic work up were negative. Kidney biopsy revealed pattern of MPGN, with prominent sub-endothelial deposits and intra-capillary hyaline pseudo thrombi, staining predominantly for IgG and lambda light chain on immunofluorescence. By electron microscopy, he also had many sub-epithelial "humps" along with sub-endothelial and mesangial deposits. This was consistent with type 1 cryoglobulinemic glomerulonephritis with superimposed PIGN. In the interim, he was started on a course of steroids and over the next 2-3 weeks his kidney function returned to baseline with resolution of proteinuria and hematuria. He was eventually taken off steroids and his kidney function has remained normal.

Conclusion

This case is unique in several aspects. First of all, although his history of LGBL could explain weak paraproteinemia, our patient showed no clinical evidence of lymphoma on routine monitoring by Hematology. Moreover, we had no compelling reason to believe that he had an indolent lymphoproliferative disease causing his renal failure. Secondly, his quick and full recovery is consistent with a self-limiting acute process, possibly from Influenza. Thirdly, this case represents a rare finding of PIGN associated with influenza. We think concurrent findings of type 1 cryoglobulinemic MPGN associated with paraproteinemia and PIGN in this case, are likely a manifestation of the disease spectrum related to Influenza.

Funding

  • Clinical Revenue Support