Human Rhinovirus Pneumonia in Hematopoietic Stem Cell Transplant Recipients

Hematopoietic stem cell transplant (HSCT) patients experience severe immunosuppression, rendering them susceptible to opportunistic infections. Human rhinovirus (HRV) is one of the most common viral infections in HSCT recipients and while it typically infects only the upper respiratory tract, it can progress to pneumonia, sometimes resulting in severe disease or death. Little is known about the risk factors for morbidity and mortality from HRV pneumonia. We retrospectively reviewed the records of 91 HSCT patients who had HRV detected in a bronchoalveolar lavage (BAL) post-transplant between 9/1999 and 5/2012. Respiratory samples from each patient were evaluated using culture and/or real time reverse-transcriptase polymerase chain reaction methods (RT-PCR). Data regarding demographic factors, transplant information, use of immunosuppressive drugs and disease progression were collected to identify possible risk factors and prognostic indicators. Patients received either autologous transplants (16%; n=15) or allogeneic transplants (84%; n=76). The average age of patients at time of HRV pneumonia diagnosis was 44 years (range: 1 to 70 years) and the median time between diagnosis and transplant was 100 days (range: 0 to 3596 days). Copathogens at the time of HRV diagnosis were identified in 82% of patients (n=75). Altogether, 24% of patients (n=22) died within 30 days following diagnosis of HRV and 20 of these 22 patients (91%) died from respiratory failure. Our ongoing analyses will identify clinical variables associated with poor disease outcome. These findings will contribute to improved prevention and monitoring of HRV infections and viral pneumonia in HSCT recipients.