Routine Prophylaxis of Pneumocystis Jirovecii Pneumonia in Recipients of Autologous Hematopoietic Stem Cell Transplantation

BACKGROUND:  Pneumocystis jirovecii pneumonia (PJP) is a potentially life-threatening disease in immunocompromised patients.  The at-risk population includes patients with HIV infection and low CD4 counts, hematological malignancies, hematopoietic stem cell (HSC) and solid organ transplant recipients, and patients receiving glucocorticoids or other immunomodulatory agents.  The highest-risk group of immunocompromised patients tends to be those with HIV (human immunodeficiency virus) infection, where PJ follows an indolent course. However, in non-HIV immunocompromised patients, such as HSC transplant recipients, the infection tends to present with respiratory failure. The incidence of PJP in autologous BMT (bone marrow transplant) has not been clearly determined, and the indication for prophylaxis in this setting remains unclear. In this study we evaluate the incidence of PJP over a 10-year period in recipients of autologous transplants. METHODS:  A retrospective analysis of 1191 consecutive autologous HSC transplants (1-75 years) performed between 1/1/2000 and 6/30/2011 at the University of Michigan BMT Program. The data was obtained from BMT Program Database at The University of Michigan Comprehensive Cancer Center. The diagnosis of PJP was established by bronchoscopy with brochoaveolar lavage (BAL) with polymerase chain reaction (PCR). We analyzed the following risk factors for the development of PJP: diabetes, glucocorticoids, infections, cutaneous T-cell lymphoma, hypertension, and seizure disorder. RESULTS: A total number of 5 PJ infections were diagnosed during study period, resulting in a cumulative incidence of 0.42% (95%CI [0.136449%--0.976969%]) over 10 year period. All cases occurred between 2001 and 2006, and 3 months or later following transplantation. Most patients (n=4) were older than 50 years old, and all of them were on steroids. Diagnoses included non-Hodgkin’s lymphoma (n=3), Hodgkin’s lymphoma (n=1) and multiple myeloma (n=1). Conditioning regimen was BEAM (BCNU, etoposide, cytarabine, melphalan, n=4) and high dose melphalan (n=1). Only 2/5 patients were neutropenic at the time of the pneumonia, and this did not correlate with the CD34+ cell infused, which was ≥2.2x10E6/kg for all patients. Four patients were on corticosteroids for relapsed lymphoma (n=2), ITP (n=1), BCNU pneumonitis (n=1). The remainder patient was on florinef and was coinfected with candida and herpes virus. There were no particular comorbidities associated with the diagnosis of PJ pneumonia. One patient died of PJ, the remainder were treated successfully. CONCLUSIONS: Our retrospective analysis of a large cohort of autologous transplant recipients reveals an extremely low incidence of PJP, suggesting that PJP prophylaxis is not routinely warranted in this patient population. Patients who require systemic corticosteroids post–HSC may be considered for PJ prophylaxis.