Rituximab-associated vasculitis flare linked to higher mortality rate

Rituximab (RTX)-related cryoglobulinemia vasculitis flare may lead to poorer survival, reveals a study.

“We provided evidence that kidney lesions are due to immune complex deposition and to glomerular obstruction by cryoglobulinemia and RTX,” the authors said.

This retrospective study was carried out from 2005 to 2015 in a tertiary referral centre. Disease flare was characterized as the onset of a new organ involvement or worsening of autoimmune disease within 4 weeks following RTX treatment.

A total of 185 patients were included. Seven disease flares (3.4 percent) were identified among these individuals, all due to type II mixed cryoglobulinemia vasculitis. Disease flare occurred after a median of 8 days (range, 2–16) following RTX infusion. This included kidney insufficiency (n=7), purpura with cutaneous (n=7), gastrointestinal tract involvement (n=4), and myocarditis (n=1).

The following conditions more frequently occurred in patients with RTX-associated vasculitis flare compared to those without flare after RTX (n=43): renal involvement (p=0.0008), B cell lymphoproliferation (p=0.015), higher level of cryoglobulin (2.1 vs 0.4 g/l; p=0.0004), and lower level of C4 (0.02 vs 0.05; p=0.023).

Four patients (57 percent) died after a median time of 3.3 months. Those with RTX-related vasculitis flare had poorer 1-year survival rate (43 percent, 95 percent confidence interval [CI], 18–100) than their negative counterparts (97 percent, 95 percent CI, 92–100; p<0.001).

Additionally, immunofluorescence analysis of kidney biopsy in patients with worsening RTX-related vasculitis emphasized the presence of RTX-, immunoglobulin (Ig)M-, and IgG1-positive straining of endomembranous deposits and thrombi within kidney lesions, according to the authors.