Clinical and Economic Issues in Multiply Transfused Sickle Cell Disease (SCD) Patients.
Authors: Sakhalkar Vishwas S. , Veillon Diana M. , Cotelingam James D. , Hawthorne Linda M. , Caldito Gloria C. , McCaskill Deborah M. 
Published: October 2019

Abstract
Aim: To study alloantibody (alloAB)/autoAB formation and transfusion reactions in SCD patients before and after instituting the practice of transfusing C, E, K blood type negative (CEKneg) packed red blood cell (pRBC) units.
Material and Methods: We retrospectively reviewed blood bank records of all SCD patients transfused pRBCs. Statistical analysis was performed using the Chi square test and Fischer’s exact test.
Results: During 1990–2004, 500 SCD patients received 16,617 pRBCs in our hospital. 387 received pRBCs crossmatched for ABO and Rh only; 121 (31.3%) developed alloantibodies (alloABs).
Table 1: Transfusion characteristics of patients forming alloABs Data on pts forming alloABs CEK matched patients CEK unmatched pRBC Transfusion (Tn) patients (387) ≥ 1 ABs ≥ 2 ABs ≥ 3 ABs ≥ 4 ABs ≥ 5 ABs Number of patients (% of total) 6/113 (5%) 121/387(31%) 57/121 (47%) 29/57 (51%) 16/29 (55%) 11/29 (69%) # of Tn before AB-Median (range) 9.5 (0-106) 7(0-270) 2 (0-106) 0 (0-89) 0 (0-180) 0 (0-16) # of pts with > 5 Tn before AB 4/6 (67%) 68/121(56%) 21/57 (37%) 5/29 (17%) 4/16 (25%) 1/11 (9%) # of pts with >30 Tn before AB 1 12 4 2 1 0
There were 37 transfusion reactions: 9 febrile, 24 allergic and 4 dHTRs, none was life-threatening. 21 pts developed multiple alloABs simultaneously after a single transfusion; 15 additionally developed warm autoABs. >13% patients transfused CEK unmatched units developed ABs to C, E, K and other antigens. Once allosensitized, there was an ↑ chance of subsequent development of multiple alloABs with fewer transfusions.
Table 2: Incidence of antibody formation in patient groups Major patient groups Total # of pts Total # of transfusions Number of allo ABs (%of pts) [Incidence/1000 pRBCs] Number of autoABs (%of pts) [Incidence/1000 pRBCs] All Non-CEK Total Warm P value (CEK vs Regular) - # of pts <0.001 0.03 0.005 0.02 CEKmatched 113 2354 6 (5%)[2.55] 5(4%)[2.12] 1 (0.88%)[0.425] 1 (1%)[0.46] Regular (ABORh) 387 14263 240(31%)[16.8] 76 (13%)[5.33] 39 (10%)[2.73] 30 (8%)[2.1] alloAB forming pts 121 7338 240[32.71] 76[10.36] 34 (28%)[4.63] 30 (25%)[4.1] No alloAB pts 266 6925 N/A N/A 5 (2%)[0.7] 0 P value(alloAB vs non-alloAB) - # of pts N/A N/A <0.001 <0.001
Of 266 patients who did not develop any alloABs, 5 had cold and no warm autoABs. 113 patients received 2354 CEKneg pRBCs only (from 1997), 6 (p<0.01) had one alloAB each, 1 warm autoAB and no reactions. Technologists required 30 more minutes and $153 extra in reagent costs for extended CEK match. 90% of our donors are Caucasian.
Conclusions: Utilizing CEK negative pRBCs ↓↓ alloAB(p<0.01), autoAB (p<0.001) formation and eliminated transfusion reactions in our multiply transfused SCD patients. Universal availability of leukopoor pRBCs (from 1997) may have eliminated febrile reactions. There was ↓ alloAB formation for C, E, K and other blood group antigens. Though unlikely, Rh neg and CEKneg pRBCs may also be negative for other minor antigens. AutoAB formation (and allergic reactions)especially ↑ in patients with multiple and simultaneous alloAB formation. CEK matching made it easier to find pRBCs due to less formation of alloABs. However, it resulted in marked overuse of Rh neg pRBCs and extra cost and effort to find CEKneg pRBCs for every transfusion. For cost efficacy, one might consider CEKneg pRBCs after first alloAB.