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Plateletpheresis-associated lymphopenia in frequent platelet donors

John M. Gansner, Mahboubeh Rahmani, A. Helena Jonsson, Brooke M. Fortin, Idayat Brimah, Martha Ellis, Robin Smeland-Wagman, Zhihan J. Li, Jason M. Schenkel, Michael B. Brenner, Revital Yefidoff-Freedman, Steven R. Sloan, Nancy Berliner, Nicolas C. Issa, Lindsey R. Baden, Dan L. Longo, Duane R. Wesemann, Donna Neuberg, Deepak A. Rao and Richard M. Kaufman

Key points

  • Frequent apheresis platelet donors may have very low CD4+ and CD8+ T-cell counts.

  • The cytopenias do not appear harmful.

Abstract

Over one million apheresis platelet collections are performed annually in the United States. After two healthy plateletpheresis donors were incidentally found to have low CD4+ T-lymphocyte counts, we investigated whether plateletpheresis causes lymphopenia. We conducted a cross-sectional, single-center study of platelet donors undergoing plateletpheresis with the Trima Accel, which removes leukocytes continuously with its leukoreduction system chamber. We recruited three groups of platelet donors based on the total number of plateletpheresis sessions in the prior 365 days: 1-2, 3-19, or 20-24. CD4+ T-lymphocyte counts were below 200 cells/µL in 0/20 donors in the 1-2 sessions group, 2/20 donors in the 3-19 group and 6/20 donors in the 20-24 group (P=0.019). CD8+ T-lymphocyte counts were low in 0/20 donors in the 1-2 group, 4/20 donors in the 3-19 group, and 11/20 donors in the 20-24 group (P<0.001). The leukoreduction system chamber's lymphocyte extraction efficiency was ~15-20% for all groups. Immunophenotyping showed decreases in naive CD4+ T-lymphocyte and Th17 percentages, increases in CD4+ and CD8+ effector memory, Th1, and Treg percentages, and stable naive CD8+ and Th2 percentages across groups. T-cell receptor repertoire analyses showed similar clonal diversity in all groups. Donor screening questionnaires supported the good health of the donors, who tested negative at each donation for multiple pathogens, including HIV. Frequent plateletpheresis utilizing a leukoreduction system chamber is associated with CD4+ and CD8+ T-cell lymphopenia in healthy platelet donors. The mechanism may be repeated extraction of these cells during plateletpheresis. The cytopenias do not appear to be harmful.

  • Submitted September 17, 2018.
  • Accepted November 8, 2018.