Plasma Exchanceto Prevent Cyroglobulinemic Vasculitis Flare in Sjogren Membranoproliferative Glomerulonephritis

Introduction: Cryoglobulinemia related membranoproliferative glomerulonephritis (MPGN) is a described manifestation of renal disease in Sjogren’s. Treatment involves steroid therapy and rituximab. Plasma exchange (PLEX) can reduce the incidence of rituximab induced cyroglobulinemic vasculitis (CV) flare. There are differences in literature on when to initiate PLEX prior to rituximab. We describe a case of Sjogren’s related MPGN requiring PLEX prior to rituximab in order to prevent CV flare. Case Description: 73y.o female with PMH of Sjogren's, HTN, HF, noted to have 2.8 g/g of proteinuria and a rise in serum Cr from 1 mg/dL-1.5 mg/dL over a 2-month period. Serology showed positive:anti-SSA (>8), ANA (>1:640), anti-smooth muscle (23.84), cryocrit (79%) and rheumatoid factor (RF) (69.86). Decreased:C3 (89 mg/dL) / C4 (3 mg/dL) and elevated IgM (1139 mg/dL). Hepatitis B/C and HIV were negative. Kidney biopsy showed MPGN and tubulointerstitial nephritis. She was initiated on a prednisone taper, and underwent PLEX prior to rituximab. Discussion: Risk factors for rituximab induced CV flare are:an elevated cryocrit percentage, extremely low C4 and positive RF. Vascular damage is related to classical pathway activation by both RF-positive IgM cryoglobulin and IgG1 of rituximab. PLEX reduces the incidence of flare. There are differences in the literature on what criteria should be used to determine PLEX prior to rituximab. One recommendation is for IgM levels >4g/dL; our pts levels were lower at 1.1 g/dL. However, other sources recommend PLEX for a cryocrit percentage of >10%, and her cryocrit level was 79%. We suggest that patients with cryoglobulinemic MPGN that meet any of the criteria for possible rituximab induced flare, PLEX therapy should be considered prior to rituximab.A) MPGN injury B) Tubulointerstitial inflammation C) IgM+ plasma cells