Incidence and risk factors for graft failure in the modern era of cord blood transplantation.

BACKGROUND AND OBJECTIVES: Graft failure (GF) after cord blood transplant (CBT) has decreased with improved supportive care and cord selection strategies. We aimed to evaluate cord blood selection and factors associated with retransplantation on the incidence of GF, determine risk factors for GF including host antibodies to Kell antigen and evaluate survival after GF. MATERIALS AND METHODS: We retrospectively reviewed 84 patients who underwent CBT at the University of Oklahoma between 2000 and 2016 and compared outcomes in patients with/without engraftment by Day 28. The nonengraftment cohort was further divided into patients who underwent retransplantation. Kaplan-Meier curves with log-rank tests were calculated to assess the association between mortality and engraftment. RESULTS: Engraftment following CBT was high at 81%, with 52% engrafting by Day 28 and an additional 29% engrafting by a median of 36 days. Retransplantation led to 88% engraftment at a median of 53 days. Overall, 75% of the 40 patients who did not engraft by Day 28 died. Female sex and total nucleated cell count < 3.5/kg were significantly associated with lack of engraftment and higher mortality. Antibodies to Kell fetal antigen were not identified. Retransplantation by Day 28 for primary GF conferred a survival advantage. CONCLUSION: This study demonstrates that failure to engraft by 28 days was associated with increased mortality, and risk was mitigated with early retransplantation. Female sex and low total cell dose were associated with increased mortality. Early identification of GF coupled with early retransplantation can reduce mortality in CBT.

Microbial contamination of hematopoietic progenitor cell grafts-incidence, clinical outcome, and cost-effectiveness: an analysis of 735 grafts.

BACKGROUND: Screening of progenitor cell grafts (marrow, peripheral blood, and cord blood) for microbial contamination is required by the standards of AABB. Clinical sequelae from infusion of these contaminated grafts, however, is uncommon. STUDY DESIGN AND METHODS: A retrospective analysis of 735 consecutive marrow and peripheral blood progenitor cell harvests between 1998 and 2003 was performed. Analysis included incidence, clinical outcome, and cost outcomes of positive blood cultures and antibiotic therapy. RESULTS: Thirty-three of 735 (4.5%) harvests were contaminated. The incidence of microbial contamination varied with the source of the graft (4 of 26 [15%] were cord blood, 8 of 177 [4.5%] were marrow, and 21 of 532 [3.9%] were peripheral blood). Coagulase-negative Staphylococcus (n=22) and Propionibacterium acnes (n=8) were most frequently isolated. Potentially pathogenic organisms were isolated in 6 of 735 (0.81%) grafts (methicillin-sensitive Staphylococcus aureus, 4; methicillin-resistant S. aureus, 1; and Enterobacter cloacae, 1). The estimated total cost of surveillance was approximately $81,585. The cost of vancomycin therapy in 4 patients who received prophylactic antibiotic therapy was approximately $10,000. No adverse sequelae followed infusion of contaminated grafts. CONCLUSION: Clinical sequelae following infusion of microbially contaminated progenitor cells is extremely rare. Prophylactic empiric antibiotics may be unnecessary. Routine microbial surveillance of progenitor cell grafts is a low-yield procedure.