m-TOR inhibitors and risk of Pneumocystis pneumonia after solid organ transplantation: a systematic review and meta-analysis

Purpose Although there is controversy, some evidences proposed increased risk of post-transplant Pneumocystis carinii pneumonia (PCP) in patients receiving mammalian target of rapamycin (mTOR) inhibitors. This study aimed to examine the association between m-TOR inhibitors and the risk of developing PCP in solid organ transplant (SOT) recipients. Methods A comprehensive search was performed to find the eligible studies that investigated the incidence of PCP in patients treated with mTOR inhibitors after SOT. Random effect model was applied for meta-analysis. Results Combination of 15 effect sizes showed a significant positive association between mTOR inhibitor administration and the risk of PCP (OR = 1.90, 95%CIs = 1.44, 2.75). There was no heterogeneity between studies (I-2 = 3.5%). Subgroup analysis revealed increased risk of PCP after the first year of transplantation (P < 0.001). Conclusion In conclusion, administration of mTOR inhibitors is a potential risk factor for late-onset PCP after SOT. Targeted PCP prophylaxis based on recipients' risk factors rather universal prophylaxis may lessen the risk.