Late-onset Pneumocystis jirovecii pneumonia in solid organ transplant recipients.

Anti-Pneumocystis prophylaxis is recommended for at least 6-12 months after solid organ transplantation, as most cases of Pneumocystis jirovecii pneumonia (PCP) occur during the first year post transplantation. Herein, we report 4 cases of late-onset PCP (>1 year post transplant). PCP appeared in a range of 50-68 months post transplant. Two cases had history of humoral rejection episodes treated with rituximab, and the other 2 had low CD4+ T-cell count (<200 cells/mm(3) ) at the time of diagnosis. All 4 patients survived. In conclusion, although the number of cases is low, we must be aware of the possibility of late-onset PCP in solid organ transplant patients. The role of previous use of rituximab or persistent CD4+ T-cell lymphopenia should be addressed in future studies.