INFLUENCE OF PROTECTIVE ISOLATION ON OUTCOME OF ALLOGENEIC BONE-MARROW TRANSPLANTATION FOR LEUKEMIA

Various isolation strategies are used to prevent infections during bon e marrow transplantation; data on their efficacy are lacking. We studi ed whether use of high efficiency particulate air filtration (HEPA) an d/or laminar airflow (LAF) units affect transplant-related mortality ( TRM) or survival in the first year after allogeneic transplantation. 5 065 patients with leukemia receiving bone marrow transplants from an H LA identical sibling (n = 3982) or alternative related or unrelated do nors (n = 1083) between 1988 and 1992 were reported to the Internation al Bone Marrow Transplant Registry by 222 teams. Two types of isolatio n were considered: (1) conventional protective isolation with single p atient room and any combination of hand-washing, gloves, mask and gown ; and (2) HEPA and/or LAF. Cox proportional hazards regression models were used to determine the relative risks (RRs) of transplant-related mortality (TRM) and of deaths from any cause in patients treated in HE PA/LAF units compared to patients treated in conventional isolation. H LA-identical sibling and alternative donor transplants were analyzed s eparately. Risks of TRM and overall mortality in the first 100 days po st-transplant were significantly lower among patients treated in HEPA/ LAF units than in those treated conventionally. RRs of TRM were 0.76 ( P = 0.009) for recipients of HLA-identical sibling transplants and 0.6 5 (P = 0.003) for recipients of alternative donor transplants. Corresp ondingly RRs of overall mortality were 0.80 (P = 0.02) and 0.65 (P = 0 .0006). Decreased risks of TRM and of death in the first 100 days post -transplant resulted in significantly higher 1-year survival rates in patients treated in HEPA/LAF rather than in conventional isolation uni ts. Use of HEPA and/or LAF to prevent infections decreases TRM and inc reases survival after allogeneic bone marrow transplants for leukemia.