No abstract

The erythrocytes of a normal man were agglutinated more weakly than normal cells by several anti-P(1)OO^k sera, and exhibited a decreased capacity to absorb these antibodies. Analysis of his erythrocyte glycosphingolipids revealed that the globoside (P antigen) content was less than 25% of normal, and trihexosyl ceramide (the Pk antigen) was 30-40% of normal. The ganglioside content of his erythrocytes was approximately four times normal and sialosylparagloboside was increased about sixfold. It appears that his erythrocytes are unable to synthesize normal quantities of trihexosyl ceramide, and that these serological and chemical features constitute a new phenotype in the P blood group system.

The authors report a case of paroxysmal cold hemoglobinuria (PCH) with pronounced erythrophagocytosis by segmented neutrophils. This type of erythrophagocytosis, though well-documented in vitro, is a rare phenomenon in vivo. A review of the literature shows an association between PCH and erythrophagocytosis by segmented neutrophils that the authors suggest may have diagnostic value.

In November 1984, the Standards Committee of the American Association of Blood Banks changed the requirements for pretransfusion testing by making the performance of an antiglobulin crossmatch optional when the antibody screening test is negative. The crossmatch would be necessary only to confirm ABO compatibility. Many will welcome this change; others will persist in their current methods. This article presents data supporting the use of the manual hexadimethrine bromide (Polybrene) test, a 1-minute room temperature procedure, as a crossmatch technique when the antibody screening test is negative. The manual Polybrene test (MPT) is an effective method for detecting ABO incompatibility. Forty-seven randomly selected serums gave expected results with A1, A2, and B red cells. Only 66 percent of 84 group B sera were serologically incompatible with A2B red cells by MPT, but the same results (69% positive) were observed using a 5-minute low-ionic-strength solution (LISS) room temperature technique. As only 37 percent of these crossmatches were incompatible using a LISS immediate spin (IS) method, the reliability of an IS method is questioned. An MPT crossmatch provides added security in that most unexpected blood group antibodies are demonstrable by this method. Of 106 serums tested which contained antibodies, 83 reacted. We believe that the MPT provides a rapid and sensitive test that, accompanied by a carefully performed antibody screening test, meets the requirements of Standards and will provide for safe red cell transfusion without the need for an antiglobulin crossmatch.