Prevention of refractoriness and HLA-alloimmunization using filtered blood products

Abstract

Depletion of leukocytes from all blood products may decrease the incidence of alloimmunization to HLA antigens present on the white cells and thus delay the onset of refractoriness to random donor platelet support. In order to test this hypothesis, 54 patients with hematologic malignancy or marrow aplasia were entered on a prospective randomized trial using cotton-wool filtration as a method of leukocyte depletion of red cell and platelet concentrates. Forty patients were considered evaluable; 20 patients received filtered products and 20 patients in the control group received standard unfiltered products. The filter was 99% efficient in removal of leukocytes (average number of WBC/platelet product, 6 X 10(6)). Platelet loss by this technique was 8%. Alloimmunization was assessed by detection of de novo formed lymphocytotoxic and platelet specific antibodies by microcytotoxicity test, Staph A protein radioimmunoassay, and solid phase red cell adherence test. In the group receiving filtered products, three of 20 (15%) patients developed lymphocytotoxic antibodies while ten of 20 (50%) patients in the control group developed cytotoxic antibodies (P = .01 by actuarial methods). Platelet antibodies were detected in seven of ten alloimmunized patients in the control group and three of three patients in the study group. Clinical evidence of refractoriness was seen in three of 20 patients in the filtered group and ten of 20 in the control group (P = .01 by actuarial methods). The cost of filtration was a fraction of the cost of a plateletpheresis product. Filtration appears to be an effective and economical method for reducing alloimmunization and clinical refractoriness to random donor platelets in patient receiving long-term transfusion support.

Effects on erythropoiesis of alemtuzumab‐containing reduced intensity and standard conditioning regimens

“…Our estimates of PRCA incidence are similar to the previously reported ones (Sniecinski et al, 1988), which are distinctly lower than 29-30% recently quoted in the setting of major/bidirectional ABO mismatch in RIC transplantation (Bolan et al, 2001;Worel et al, 2003). Few reports specify reticulocyte counts required for the diagnosis of PRCA, or define the interval to expected erythroid recovery after transplantation; thus the lack of standard diagnostic criteria may preclude comparisons with other reports.…”

Platelet transfusion refractoriness

“…Several studies of AML patients receiving induction chemotherapy examined the effect of leucoreduction on the incidence of alloimmunization. The incidence dropped from 48% to 16% in one study (Murphy et al, 1986), from 50% to 15% in another (Sniecinski et al, 1988), and from 45% to 17-21% in the TRAP Study (Slichter, 1997). The TRAP study also showed no difference in the rate of alloimmunization between leucoreduced single-donor (i.e.…”

Synthesis and performance of amphiphilic copolymers for blood cell separation

“…Cell separation is a key process involved in leukocyte removal from blood cells for transfusion [1][2][3][4][5] and isolation of stem cells from peripheral and umbilical cord blood. 6,7 Polyurethane foam membranes [1][2][3]6,7 and nonwoven fabrics, 4 with pore sizes of 5-20 m, have been used as separation membranes for blood cells. The surfaces of these membranes are generally modified by grafting 6,7 or coating 4,5 with biocompatible polymers, to improve the hemocompatibility and control the hydrophilic-hydrophobic properties of the surface of the membranes.…”