Abstract
There are some reports of severe anaphylactic shock after the transfusion of blood products containing a plasma protein in haptoglobin (Hp)-deficient patients with an anti-Hp antibody. We encountered two Hp-deficient patients who were homozygous for a deleted allele of the Hp gene. These two patients did not have an adverse reaction to the transfusion of two-time washed red cells. We examined the correlation between the number of washes and the haptoglobin concentration remaining in blood products. We measured the Hp concentration in five blood products of washed red cells (WRC), frozen-thawed red cells (FTRC), and washed platelet concentrate (WPC). The mean Hp concentration of red blood cells (RBC) was 98.800 μg/ml, that of the one-time washed WRC was 3.044 μg/ml, that of the two-time washed WRC was 0.233 μg/ml, and that of the three-time washed WRC was 0.038 μg/ml. The p-values of the one-, two-, and three-time washed WRC were 0.0089, 0.0019, and <0.0001, respectively. The mean Hp concentration of FTRC was 5.116 μg/ml. The mean Hp concentration of platelet concentrate (PC) was 656.600 μg/ml, that of the one-time washed WPC was 7.262 μg/ml, and that of the two-time washed WPC was 0.463 μg/ml. The p-values of the one- and two-time washed WPC were <0.0001 and 0.0016, respectively. Based on these results, it is desirable to transfuse two-time washed WRC and WPC to Hp-deficient patients with an anti-Hp antibody.
