Parainfluenza virus (PIV)
infections may be significant causes of morbidity and mortality in patients undergoing
stem cell transplantation, but data regarding their impact on transplant-related mortality is limited. This study sought to determine the risk factors of PIV acquisition and progression to lower
respiratory tract infection, their impact on transplant-related mortality, and the effectiveness of
antiviral therapy. A total of 3577 recipients of
hematopoietic stem cell transplantation (HSCT) between 1990 and 1999 were studied. PIV
infections occurred in 253 patients (7.1%); 78% of these
infections were community acquired. Multivariable analysis identified the receipt of an unrelated transplant as the only risk factor for PIV acquisition; the dose of
corticosteroids at the time of PIV
infection acquisition was the primary factor associated with the development of PIV-3
pneumonia, both among allogeneic and autologous HSCT recipients. Both PIV-3 upper respiratory
infection and
pneumonia were associated with overall mortality. Pulmonary copathogens were isolated from 29 patients (53%) with
pneumonia. Mortality was highly influenced by the presence of copathogens and the need for
mechanical ventilation. Aerosolized
ribavirin with or without
intravenous immunoglobulin did not appear to alter mortality from PIV-3
pneumonia, nor did such
therapy decrease the duration of viral shedding from the nasopharynx among patients with
pneumonia.
Corticosteroid administration thus drives the development of PIV
pneumonia in a dose-dependent fashion, even among autologous HSCT recipients. Both upper and lower tract PIV
infections are predictors of mortality after HSCT. Currently available
antiviral therapy appears to be inadequate in reducing viral shedding or mortality once
pneumonia is established. (Blood. 2001;98:573-578)