Ab initio calcineurin inhibitor-based monotherapy immunosuppression after liver transplantation reduces the risk for Pneumocystis jirovecii pneumonia

At the Tor Vergata University of Rome, ab initio calcineurin inhibitor-based monotherapy immunosuppression (IS) is the standard of treatment after liver transplantation (LT). As the net state of IS determines the onset of Pneumocystis jirovecii pneumonia (PCP), we hypothesized that, in the presence of weak impairment of the immune function, as determined by the above-mentioned IS, the host is not overexposed to the risk for PCP and consequently the specific anti-PCP prophylaxis is unnecessary. In a single-cohort descriptive study, we retrospectively investigated the incidence of PCP in 203 LT patients who did not receive anti-PCP prophylaxis because they were under monotherapy IS. The primary endpoint of the study was the incidence of PCP during the first 12 months following LT; secondary endpoints were the incidence of acute rejection requiring additional IS and of CMV infection. No cases of PCP were recorded. The incidence of CMV and acute rejection was 3.9% and 0.9%, respectively. Our data suggest that monotherapy IS after LT may nullify the risk for PCP even in the absence of any specific prophylaxis.