Is antibody-mediated rejection in kidney transplant recipients a risk factor for developing cytomegalovirus or BK virus infection? Results from a case-control study

Background Data are scarce on cytomegalovirus (CMV) and BK virus (BKV) infection after antibody-mediated rejection (ABMR). Objectives We hypothesized that the immunological response in patients with ABMR or the immune modulation associated with its treatment could predispose to CMV and BKV infection. Our objective was to investigate this hypothesis. Study design We conducted a single-center, matched case-control study (1:2 ratio) to analyze CMV and BKV replication during the first year after the ABMR diagnosis in kidney transplant recipients. Adult recipients with a histopathological diagnosis of ABMR between 2007–2015 were included as cases. Controls were kidney recipients who underwent transplantation immediately before and after the index case. Results Fifty-eight patients diagnosed with ABMR (33 chronic active ABMR and 25 acute ABMR), with their matched controls (116) were included. Forty-four cases received treatment for ABMR, including plasmapheresis (41), immunoglobulins (40), and rituximab (31). Within 1 year after ABMR, cases showed CMV replication more often than controls (9/58, 15.5% vs 7/116, 6%, OR = 4.21, CI 1.10–16.16, p = 0.04). Over the study period, CMV PCR determinations were requested more frequently in cases than controls (46/58, 79.3% vs 63/116, 54.3%, OR = 4.58, CI 1.92–10.9, p = 0.001). On multivariate analysis adjusted for CMV PCR determinations, retransplantation, antithymocyte globulin treatment and methylprednisolone treatment for acute rejection, CMV replication remained more common in cases than in controls (OR = 2.41, CI 0.49–11.73, p = 0.28). There were no differences in BKV replication in either urine or blood. Conclusions ABMR may be a risk factor for CMV but not for BKV replication in kidney transplant recipients.