Epidemiology and risk factors for cytomegalovirus infection in glomerular diseases treated with immunosuppressive therapy

Background Cytomegalovirus (CMV) infections are associated with morbidity and mortality. We aimed to describe the epidemiology, risk factors and outcomes of CMV infection among patients with glomerulonephritis (GN) who received potent immunosuppressants (IS). Methods Single-centre retrospective study of adults with biopsy-proven GN prescribed methylprednisolone (MP), cyclophosphamide (CYC) or rituximab (RTX). Primary endpoint was CMV infection defined by significant CMV antigenemia (>10 positive cells in 106 cells) or viremia (>2000 copies/ml). Death was related to CMV if CMV infection occurred within the same hospitalisation as death. Results Ninety-four patients were studied. CYC was prescribed in 65% and MP in 71% of the cohort. Only 2 patients received RTX and 15 patients received plasma exchanges (PEX). Median follow up was 31.9 (IQR: 13.7, 53.6) months. CMV infection occurred in 13 patients (13.8%) at 1.3 (0.6, 3.0) months from biopsy. Patients with CMV infection had higher serum creatinine [404 (272, 619) vs. 159 (93, 317) µmol/L, p < 0.001] and greater proteinuria [UPCR 7.5, (4.8, 11.8) vs. 4.2 (2.3, 8.4) g/g, p = 0.02] than those who did not have CMV infection. Also, more patients received CYC (92% vs. 60%, p = 0.03), RTX (15% vs. 0, p = 0.02) and PEX (38% vs. 12%, p = 0.01) than those who did not have CMV infection. Two patients had CMV-related deaths. Conclusion CMV infection is common in GN patients receiving potent IS. Surveillance and possibly anti-viral prophylaxis should be considered for high-risk patients.