EFFICACY AND SAFETY OF PLATELETPHERESIS BY DONORS WITH LOW-NORMAL PLATELET COUNTS

Our practice is to defer donors with blood platelet (PLT) counts of <1 80 x 10(9)/L because PLT yields are low, when compared to PLT units co llected from donors with higher counts. In an attempt to minimize defe rral, we determined whether 33 donors, who repeatedly demonstrated low -normal PLT counts (150-180 x 10(9)/L) on multiple occasions during th e prestudy period, might safely donate satisfactory apheresis PLT unit s simply by extending the apheresis collection time by 20 min (men) an d 40 min (women). Repeat plateletpheresis procedures were scheduled at greater than or equal to 28-day intervals. The mean PLT yield (N = 92 ) was 5.8 x 10(11) with 97% of units containing greater than or equal to 4.0 x 10(11) PLTs. Although donors entered the study only after the y had repeatedly exhibited predonation PLT counts of <180 x 10(9)/L, P LT counts were not always below this level at the time of study collec tions. However, analyzing only donations with true predonation PLT cou nts of <180 x 10(9)/L (N = 35), the mean PLT yield was excellent-5.4 x 10(11) with 97% of units containing greater than or equal to 4.0 x 10 (11) PLTs. The average fall in donor blood PLT counts (pre- vs. postdo nation) was 36%, with only ten of 99 postdonation counts being <100 x 10(9)/L; the lowest was 69 x 10(9)/L. Thus, extending the apheresis co llection time permitted donors who in the past were routinely deferred because of low PLT counts to safely donate satisfactory PLT units. (C ) 1995 Wiley-Liss, Inc.