Abstract: TH-PO218

Cryoglobulinemic Glomerulonephritis in a Patient with Sjögren Syndrome

Session Information

Category: Nephrology Education

  • 1302 Fellows and Residents Case Reports

Authors

  • Noriega, Ramon, University of Texas Medical Branch, Galveston, Texas, United States
  • Kochar, Tina, University of Texas Medical Branch, Galveston, Texas, United States
  • Kassem, Hania, University of Texas Medical Branch, Galveston, Texas, United States
  • Ward, Adam J, UTMB, Galveston, Texas, United States
  • Afrouzian, Marjan, University of Texas Medical Branch, Galveston, Texas, United States
Background

Background: Sjögren’s Syndrome (SS) is a disease characterized by lympho-plasmacytic infiltration of exocrine glands. Interstitial nephritis is the most common form of renal involvement in SS. Glomerular involvement including Membranoproliferative glomerulonephritis (MPGN) is relatively rare.

Methods


Case Description: A 73 yr old Caucasian female with past medical history of uncontrolled hypertension and SS presented with fluid overload. Physical examination revealed pulmonary crackles and peripheral edema. Laboratory analysis was significant for a creatinine of 1.5 mg/dL and urine protein to creatinine ratio of 2.5g/g. Urine microscopy revealed dysmorphic red blood cells. Serologies for hepatitis B, C, HIV, cryoglobulins and ANA were negative. Serum complements were low.

Pathology: Light microscopy revealed 14 glomeruli with the following findings: global sclerosis (1), segmental sclerosis (4), endocapillary proliferation (5), and intracapillary coagula of cryoglobulins (4). Mild tubular atrophy/ interstitial fibrosis/ inflammation, mild arteriosclerosis and arteriolar onionskin pattern were also present. By immunofluorescence microscopy 12 glomeruli showed granular mesangial and capillary loop staining with IgG/Kappa/Lambda (+++), IgA and IgM (++), and C1q (+). Electron microscopic findings in 2 glomeruli included thickened glomerular basement membrane, mesangial interposition, subendothelial, subepithelial, and mesangial deposits of cryoglobulins. Cryoglobulinemic GN (secondary MPGN) in the background of SS was diagnosed.

Conclusion

Discussion: In our patient, glomerular involvement by MPGN, an uncommon pathologic manifestation of SS, was complicated by mixed cryoglobulinemia which was not detected in serum but noted on renal biopsy. This reflects the high incidence of false-negativity of serum cryoglobulin testing due to suboptimal specimen collection and handling. Our case highlights the importance of SS as a non-HCV-related cause of mixed cryoglobulinemia, and the significant role of renal biopsy. Renal insufficiency in patients with SS may not always be secondary to acute/chronic tubulo-interstitial nephritis or primary MPGN, but rather a secondary glomerular disease such as Cryoglobulinemic GN. Patient was started on prednisone with significant improvement in her symptoms and renal function and resolution of proteinuria.