Blood Stream Infection after Reduced- Intensity Unrelated Cord Blood Transplantation for Adults with Hematologic Diseases.

<Introduction>

Blood stream infection (BSI) is a major problem after cord blood transplantation (CBT). However we have little information on it after reduced-intensity cord blood transplantation (RICBT).

<Objective>

This study aims to investigate clinical characteristics of BSI within 100 days of RICBT, and to identify its risk factors in the patient who received RICBT between January 2002 and March 2004 in Toranomon hospital.

<Characteristics of patients and cord blood units/ Transplantation>

We reviewed medical records of 77 patients with advanced hematologic diseases who underwent RICBT at Toranomon Hospital between January 2002 and June 2004.

Median age of the patients was 55 years (17-79). Median number of infused cells and CD34+ cells were 0.86 x 10E7 (range; 1.73–4.31) and 0.8x10E7/kg (range; 0.01–46.1), respectively. Conditioning regimen consisted of fludarabine (125–150 mg/m2), melphalan (80–140 mg/m2), and TBI 2–8 Gy. GVHD prophylaxis was cyclosporine or tacrolimus. BSI must have met at least one of the following criteria previously described. (O’Grady, NP et al., Infect Control Hosp Epidemiol 2002)

Mortality was considered to be directly attributable to a bloodstream pathogen if the patient died within 7 day after the last positive blood culture without any other probable cause of death, The patient’s characteristics were compared between those with or without BSI by univariate analysis.

<Results>

149 episodes of BSI were observed in 31 patients. Cumulative incidence within 100 days was 0.40. Median onset was day 13 (1–98) after RICBT.

The causative organisms were P. aeruginosa (47), S. epidermidis (44), E. faecium (13), T. beigelii (6), S. maltophilia (6), E. faecalis (5), E. coli (3), A. xylosoxidans (3) and others (22). 8 patients died of septicemia directly associated with BSI. A mortality rate was 26%. The causative organism included P. aeruginosa, A. xylosoxidans, S. maltophilia, S, aureus and gram-positive rod. Use of corticosteroid (p=0.012) and time to engraftment (p=0.003) were associated with the development of BSI.

<Discussion/ Conclusion >

BSI is a major complication in our series of RICBT. Use of corticosteroid and prolonged neutropenia might have increased the risk of incidence of BSI.