Infectious complications after allogeneic stem cell transplantation: incidence in matched-related and matched-unrelated transplant settings.

BACKGROUND: Bacterial, viral, and fungal pathogens frequently cause severe, life-threatening infections in immunocompromised patients after allogeneic hematopoietic stem cell transplantation (SCT).

OBJECTIVE: To compare the frequency of infections in patients with matched-related (Group A) or with human leukocyte antigen (HLA)-matched-unrelated donors (Group B).

PATIENTS AND METHODS: Patients treated at our transplantation unit between April 2004 and April 2005 were enrolled into this analysis. Documentation comprised demographic data, conditioning treatment, stem cell source, clinical course, as well as microbiological and clinical data and mortality.

RESULTS: We analyzed 59 patients, 22 in Group A and 37 in Group B. Both groups were well balanced regarding demographic data. Diagnoses were acute myeloid leukemia (30 of 59 patients, 50.8%), multiple myeloma (15.2%), acute lymphoblastic leukemia (11.9%), and chronic myeloid leukemia (10.2%). Patients in Group A developed infections in 95.5% of the cases compared with 97.3% in patients in Group B. Most frequently detected pathogens were Staphylococcus species, human herpesvirus-6, and Epstein-Barr virus. Three proven fungal infections were detected in Group A compared with 9 proven fungal infections in Group B. Lung infiltrations were observed in equivalent incidence in both groups. Two years after transplantation, 55.9% of patients were alive (Group A: 68.2%; Group B: 48.6%, not significant).

CONCLUSION: Allogeneic SCT from HLA-matched-unrelated donors does not have a higher infection risk than patients transplanted from matched-related donors.