Pneumocystis jirovecii Pneumonia and Use of mTOR Inhibitors in Kidney Transplantation

To the Editor—We read with interest the study by Kaminski and colleagues [1] regarding Pneumocystis jirovecii pneumonia (PJP) in kidney transplant recipients. While universal prophylaxis given for 6–12 months post-transplant is highly effective, PJP may still occur after discontinuation of prophylaxis. The primary objective of the study by Kaminski et al was to identify risk factors for late-onset PJP. Their main conclusion is that chronic lymphopenia and use of corticosteroid boluses are independent risk factors for PJP and that these 2 criteria may be used to restart prophylaxis or extend its duration [1]. We commend the authors on undertaking this important study. The study also found that the use of mechanistic target of rapamycin (mTOR) inhibitors (mTORi) was independently associated with PJP occurrence [1]. This association was relatively unexpected, given that the use of mTORi was not considered as a risk factor...