Infectious complications associated with alemtuzumab use for allogeneic hematopoietic stem cell transplantation: comparison with anti-thymocyte globulin

Objectives. To evaluate the incidence of infectious complications after receiving alemtuzumab as part of a conditioning regimen for allogeneic hematopoietic stem cell transplantation (HSCT) in Korean patients. Methods. From November 2004 to January 2006, 12 patients who received alemtuzumab‐based conditioning regimens for allogeneic HSCT were evaluated retrospectively until death or until the end of the follow‐up in July 2007; they were compared with 18 patients who received rabbit anti‐thymocyte globulin (ATG)‐containing conditioning regimens from January 2002 to January 2006. Results. Post‐engraftment infections occurred more frequently in the alemtuzumab recipients than in the ATG recipients; the mean number of infections, excluding cytomegalovirus (CMV) infections, per patient during the follow‐up period was 2.6±1.4 vs. 1.0±0.8 (P=0.003), respectively. Although there was no statistical difference in the cumulative incidence of CMV infection between the 2 groups (91.7% vs. 55.6%, P=0.381), the alemtuzumab recipients had a higher incidence of CMV diseases (41.6% vs. 0%, P=0.0006) and a higher recurrence rate of CMV infection (90.0% vs. 27.3%, P=0.008) than did the ATG recipients, irrespective of the dose of alemtuzumab. Hemorrhagic cystitis (HC) (66.7% vs. 16.7%, P=0.009) and BK virus‐associated HC (41.7% vs. 5.6%, P=0.026) developed more frequently in the alemtuzumab recipients. The all‐cause mortality rate was not significantly different between the alemtuzumab and the ATG recipients (75% vs. 55.6%, P=0.28). Conclusion. Alemtuzumab recipients had a high incidence of CMV disease as well as BK virus‐associated HC compared with the ATG recipients. The dose of alemtuzumab should be tailored to patients' risk; in addition, the implementation of the appropriate prophylaxis for CMV and early detection strategies for BK virus are recommended.