Opportunistic Infections in 547 Organ Transplant Recipients Receiving Alemtuzumab, a Humanized Monoclonal CD-52 Antibody

Background. Alemtuzumab is being increasingly used for the prevention and/or treatment of acute allograft rejection in organ transplant recipients. We assessed the risks of infection in, to our knowledge, the largest cohort and broadest range of organ transplant recipients yet reported to have received alemtuzumab. Methods. All patients who received alemtuzumab from September 2002 through March 2004, either as induction therapy at the time of transplantation or for the treatment of rejection, were evaluated for the development of an opportunistic infection (OI) until death or for 12 months after receipt of the last dose of alemtuzumab. Results. A total of 547 recipients were included, 65% of whom received alemtuzumab for induction therapy only. Overall, 56 recipients (10%) developed 62 OIs, including cytomegalovirus disease (n = 16), BK virus infection (n = 12), posttransplantation lymphoproliferative disease (n = 5), human herpesvirus 6 infection (n = 1), parvovirus infection (n = 1), esophageal candidiasis (n = 12), cryptococcosis (n = 2), invasive mold infection (n = 4), Nocardia infection (n = 4), mycobacterial infection (n = 3), Balamuthia mandrillaris infection (n = 1), and toxoplasmosis (n = 1). Patients who received alemtuzumab for induction therapy were significantly less likely to develop an OI, compared with patients who received alemtuzumab for rejection therapy (4.5% vs. 21%; P < .001). Independent predictors of the development of an OI were administration of alemtuzumab for rejection therapy (odds ratio [OR], 3.5; 95% confidence interval [CI], 1.8–6.8; P < .001), allograft failure (OR, 2.1; 95% CI, 1.1–4.4; P = .04), and receipt of a lung transplant (OR, 3.7; 95% CI, 1.7–8.0; P = .001) or an intestinal transplant (OR, 8.3; 95% CI, 3.5–19.5; P < .001). Conclusions. Patients who received alemtuzumab for the treatment of allograft rejection were significantly more likely to develop an OI, compared with patients who received alemtuzumab for induction therapy only. Such data have implications for new antimicrobial prophylactic strategies.