Second Donation from Volunteer Hematopoietic Stem Cell Donors in Taiwan Tso-Fu Wang(1), Shu-Huey Chen(1), Shang-Hsien Yang(1), Chu-Yu Chang(2), Ya-Wen Chiu(2), Teng-Yi Lin(1), Ming-Hwang Shyr(1), Kuo-Liang Yang(2) (1)Hualien Tzu-Chi General Hospital Taiwan; (2)Buddhist Tzu-Chi Stem Cell Center Introduction Occasionally, unrelated hematopoietic stem cell donors may be asked to provide subsequent donations of stem cells or lymphocytes. In this study, we evaluated the frequency of and reasons for a second donation and whether donors prefer peripheral blood stem cell (PBSC) collection or bone marrow (BM) harvest. In addition, we compared the yields of and side effects associated with twice BM harvest. Materials and methods Donor characteristics, reasons for the second donation, type of second donation, and yield of BM stem cell product were abstracted from medical records. The psychosocial and physical experiences of donors who underwent two different hematopoietic stem cell collection procedures (BM and PBSC) and their preference for one procedure over the other were collected via a self-reported questionnaire. Among donors who underwent two bone marrow harvests, we compared the yields of and the side effects associated with the first and second harvest. The side effects associated with BM and PBSC harvest were compared by Chi- square test. The yield of subsequent BM harvests was compared by the Wilcoxon test. A P value less than 0.05% was considered significant. Results Among the 1738 donors analyzed, 72 had made more than one donation. The procedures included lymphocyte donations in 55 donors, BM harvest in 9 donors, and PBSC collection in 8 donors. A total of 13 donors underwent both BM and peripheral blood stem cell (PBSC) donations and 4 donors underwent two BM harvests. Five of the 17 donors donated the second collection of hematopoietic stem cells to different patients and 12 of the 17 donors donated stem cells to the same patient on both occasions. The indications for the second donation from these 12 donors were graft failure (5 of 12; 41.7 %) and disease relapse (7 of 12; 58.3%). The median recovery time associated with PBSC (1 day) was significantly shorter than that associated with BM harvest (7 days) (p=0.0083). Although most of the donors who underwent both procedures felt that BM harvest was more physically demanding, caused more pre-procedural anxiety, was more time consuming, and was more inconvenient than PBSC collection, 63.6% of them preferred BM donation. There was no significant difference in yield of stem cells between the first and second BM harvests (p=0.25). In addition, there were no significant differences in the incidence of side effects or recovery time between the first and second BM donation. Approximately 30% (5/15) of the donors had difficulty before agreeing to donate hematopoietic stem cells a second time. Among the 17 donors, 10 encountered disagreement from their relatives or friends. TNC: total nucleated cell, V: harvest volume, Density=TNC/Volume, BH: body height, BW: body weight, 1: first harvest, 2: second harvest Table 2 Characteristics and BM yield of 4 donors with twice BM harvest Conclusions Table 1. Side Effect of BM vs PBSC donation Although the case number in our study is relatively small, more donors’ preference for BM harvest over PBSC collection is different from that reported in previous studies despite similar side effects. Discomfort of PBSC apheresis procedure can explain this result partially. We decrease the process volume in low body weight donors and use skilled medical staffs to establish vascular access and more aggressive supplement of calcium gluconate to decrease adverse events associated with apheresis procedure. Percentagep value Headache BM0(0/13) PB23.1(3/13) Fatigue BM46.2(6/13) PB84.6(11/13) Bone pain BM69.2(9/13) PB46.2(6/13) Dizziness BM23.1(3/13) N/A PBN/A Insomnia BMN/A PB7.7(1/13) Vomiting BM0(0/13) N/A PBN/A Difficulty in walking BM38.5(5/13) N/A PBN/A Median recovery time (day) BM PB1 DonorTNC1TNC2V(ml)1V(ml)2Density1Density2Age1BH1BW1Interval 1,male m 2,male m 3,male m 4,male m Median P valueP=0.25P=0.375P=0.25