Retrospective Analysis of 37,287 Observation Years after Peripheral Blood Stem Cell Donation

Donor safety is of utmost importance in the setting of hematopoietic stem cell donation. Follow-up is indicated to detect potential long-term risks for donors. We sent a follow-up questionnaire to 15,445 donors of peripheral blood stem cells (PBSCs) or bone marrow (BM) within a retrospective study design. The return rate was 91.3%, resulting in 37,287 observation years for PBSC donors and 25,656 for BM donors. Most donors assessed their health conditions as very good or good and had not been hospitalized or received long-term medical treatment including prescribed medication for more than 4 weeks since donation. Although there were no differences in the frequency of reported health events, BM donors more often rated their general health as very good or good. Ninety-five percent of donors after BM or PBSC donation would consider a second stem cell donation. In total, 93 malignancies were reported. The standardized incidence ratio (SIR) for a diagnosis of any type of cancer after PBSC donation was .94 (95% CI, .70 to 1.24) with a SIR below 1 indicating a lower risk than in the age- and sex-matched population. The SIR for a diagnosis of leukemia was 0 (95% CI, 0 to 1.88). In summary, we found no evidence that either PBSC or BM donation are associated with increased risks of malignancies or other severe health problems.