High-dose chemotherapy followed by reinfusion of a high number of CD34⁺ progenitor cells is frequently associated with development of fever in the postengraftment period

Twenty-nine patients received high-dose chemotherapy and autologous stem cell transplantation from June 1997 to December 1998. The number of CD34⁺ cells reinfused was 2.4 x 10⁶ to 69.0 x 10⁶/kg. Twelve patients developed a fever in the immediate postengraftment period. One patient had a documented infection that could account for the fever; a second patient had a rash and biopsy proven acute graft-versus-host disease (GvHD) that responded to steroids. In the other 10 patients (30%) there was no identifiable cause of the fever. One of these patients received 4.2 x 10⁶ CD34⁺ cells/kg. The other nine received 22.0 x 10⁶ to 69.0 x 10⁶ CD34⁺ cells/kg. In our series of 29 patients, 9 of the 11 (82%) patients who received > 20 x 10⁶ CD34⁺ cells/kg developed fever in the postengraftment period. There was a significant association between the number of CD34⁺ cells (<20 vs. >20 x 10⁶) and occurrence of fever (odds ratio = 76.5; p = 0.00005). Even though they engrafted promptly (7 to 9 days), the fever required evaluation for infection, blood cultures, antibiotic treatment, and observation. This required additional hospitalization of 1 to 7 days. These data suggest that a high number of CD34⁺ cells is frequently associated with post-engraftment fever and prolongation of the hospital stay. Should there be an upper limit in the number of reinfused CD34⁺ cells is a question that has to be addressed and possibly studied.