Risk Evaluation and Outcome of Pneumocystis jirovecii Pneumonia in Kidney Transplant Patients

- Susceptibility of the host plays a major role in acquisition of PJP.
- Different immunosuppressive regimens are associated with different PJP risks.
- Kidney transplant patients with PJP often show severe lymphopenia.
- In the long-term course after transplantation, reinitiation of prophylaxis under certain circumstances may be considered.

Pneumocystis jirovecii pneumonia (PJP) affects immunocompromised patients. As a result of effective prophylaxis in the 1st months after kidney transplantation, PJP is increasingly diagnosed in the long term after transplantation. The present study evaluates course and outcome of PJP in a single transplant center from 2010 to 2015. Twenty-three patients presented with PJP at a mean of 53.7 ± 50.2 months after transplantation. Of these, 3 patients underwent ABO-incompatible (ABO-i) living-donor transplantation and 3 patients were treated with the use of belatacept. For risk estimation, 3 control cohorts were defined: a control group of all kidney transplant patients presenting for routine follow up (n = 575), all patients transplanted in an ABO-i setting (n = 45), and all patients treated with belatacept in our clinic (n = 69). Mortality in patients with PJP was 3/23 (13%) and graft loss after PJP was 3/23 (13%) resulting in patient and graft survivals of 87% and 73.9%, respectively. All patients were without PJP prophylaxis at time of diagnosis. Five of the 23 PJP patients received rejection therapy or dose escalation of immunosuppression 6 months before PJP infection, and 1 patient experienced acute rejection within 6 months after PJP treatment. In the course of PJP, 8 patients developed acute respiratory insufficiency. At time of PJP diagnosis, patients presented with severe lymphopenia (mean ± SD lymphocyte count, 0.64 ± 0.27/nL; normal range: 1.5-3/nL). Patients after ABO-i transplantation, as well as patients treated with belatacept, showed an increased risk for PJP (7.3% and 4.3%, respectively); however, in belatacept patients, other risk factors, such as age, low estimated glomerular filtration rate (eGFR), and lymphopenia seemed to contribute to this increased risk.