BACTERIAL-CONTAMINATION OF AUTOLOGOUS BONE-MARROW - REINFUSION OF CULTURE-POSITIVE GRAFTS DOES NOT RESULT IN CLINICAL SEQUELAE DURING THE POSTTRANSPLANTATION COURSE

Objectives: Microbiological cultures and posttransplantation course we re analyzed in order to investigate the incidence and clinical signifi cance of bacterial contamination of autologous bone marrow (BM) grafts , Methods: Cultures were obtained from BM after collection, BM concent rate after processing, contaminated/cryopreserved BM at thawing, and f rom peripheral blood (PB) following autologous BM transplantation (ABM T). The posttransplantation course of patients grafted with culture-po sitive BM was recorded and compared with patients who underwent ABMT w ith noncontaminated BM grafts. Results: In 239 BM grafts processed, th e incidence of microbiological contamination was 26.4% (n = 63), Fifty marrow grafts were contaminated by bacteria from the skin flora: coag ulase-negative Staphylococcus (CNSC), Propionibacterium, and Corynebac terium species (79%). Thirty-eight patients underwent ABMT(day 0) with cryopreserved culture-positive BM, and 32 patients were evaluable for microbiological cultures at thawing: in 10 of 32 BM grafts CNSC was f ound prior to reinfusion. Following ABMT, PB cultures revealed CNSC in 5 of 38 patients between days +4 and +12, However, the late occurrenc e of positive PB cultures after BM reinfusion made a relationship betw een BM CNSC and PB CNSC unlikely. In 33 of 38 patients, no graft-conta minating bacteria were detected in PB. Comparison of the posttransplan tation course of patients who received contaminated BM with that of pa tients grafted with noncontaminated BM showed no significant differenc es concerning time to engraftment, febrile days,and days on antibiotic s, Conclusion: (1) Collection and/or ex vivo processing can result ill microbiological contamination of BM grafts predominantly with bacteri a from the skin flora, and (2) only CNSC call be cultured at thawing f rom previously contaminated/cryopreserved BM. Since patients undergoin g ABMT usually receive oral antibiotics from beginning of the conditio ning regimen which are active against CNSC, no further administration of antibiotics is recommended for the reinfusion of bacterially contam inated BM grafts.