Abstract: TH-PO175

A Unique Case of IgA Cryoglobulinemia in the Setting of Staphylococcus aureus Infection

Session Information

Category: Nephrology Education

  • 1302 Fellows and Residents Case Reports

Authors

  • Jenkins, Stephen Lars, University of Utah Hospital, Salt lake, Utah, United States
  • Romney, Pace, University of Utah Hospital, Salt lake, Utah, United States
  • Marji, Catreena, University of Utah Hospital, Salt lake, Utah, United States
  • Al-Rabadi, Laith, University of Utah Hospital, Salt lake, Utah, United States
Background

IgA cryoglobulinemia is a rare entity with scarce literature regarding its pathogenesis and management. Herein, we describe a case of IgA cryoglobulinemia in the setting of Staphylococcus aureus infection.

Methods

A 75-year-old Caucasian man presented to the hospital with a two-week history of progressive weakness, lower extremity edema and decreased urine output. He was in acute renal failure with a serum creatinine of 8 mg/dL and serum potassium of 7 mmol/L. Urinalysis upon presentation was strongly positive for protein and blood. Urine microscopy revealed many red blood cells that were normal in shape with no cellular casts. Acute hemodialysis was initiated for hyperkalemia. His history was relevant for a chronic left foot ulcer infected with methicillin-sensitive Staphylococcus aureus (MSSA), for which he was receiving antibiotics.

He was found to have a low serum C3 level of 41 mg/dL and a normal C4 at 28 mg/dL. Serum cyroglobulins were detected. Further workup was negative for ANA, ANCA, anti-GBM antibody and hepatitis serologies. Immunofixation serum testing revealed a polyclonal increase in IgA without monoclonal proteins.

Biopsy of the kidney was performed and revealed glomeruli with diffuse endocapillary proliferation, frequent luminal neutrophils, few weakly PAS-positive hyaline thrombi, and more than 50% cellular crescents. Immunofluorescence showed capillary wall deposits in a mesangial and intraluminal distribution that were predominantly positive for C3 and, less intensely, for IgA and light chains. Electron microscopy revealed several mesangial, subendothelial and intraluminal deposits. The frequent intraluminal deposits suggested possible cryoglobulinemic glomerulonephritis, which can rarely be IgA-related. The patient did not receive steroids given his ongoing infection. He continued to require intermittent hemodialysis.

Conclusion

The presence of frequent glomerular neutrophils and C3 staining of higher intensity than IgA should raise concern for infection-related glomerulonephritis. Intraluminal deposits forming hyaline pseudo-thrombi and prominent hypercellularity should lead to consideration for cryoglobulinemic glomerulonephritis. There are no current recommendations for treating infection-related IgA cryoglobulinemia. Management should focus on supportive care while treating the primary infectious process.