In vitro storage and in vivo survival studies of red cells from persons with the In(Lu) gene.

Red cells (RBCs) of individuals with the In(Lu) gene are characterized by suppression of the Lutheran, P1, i, and other blood group antigens, acanthocytosis, and abnormal electrolyte metabolism. To determine the clinical significance of these abnormalities, the survival of autologous RBCs was determined by 51Cr in two siblings with the dominant Lu(a-b-) [In(Lu)] phenotype. Both subjects studied had normal hemoglobin, hematocrit, reticulocyte count, haptoglobin, and ferritin values. RBC indices were mildly hypochromic. Examination of the peripheral smear showed mild acanthocytosis in one individual. Analysis of RBC distribution on discontinuous density gradients showed a shift to lighter fractions than normal control RBCs. Storage of these Lu (a-b-) RBCs at 4 degrees C showed significant hemolysis within a few days; this was confirmed by increased autohemolysis, which was reduced by glucose and ATP. RBC cation content (sodium and potassium) was higher than that in control cells, which indicated increased cell hydration, which explains the lighter density and mild hypochromia of the Lu(a-b-) RBCs. 51Cr survival of autologous Lu(a-b-) RBCs was normal in both subjects studied. The data indicate that the morphologic and cation abnormalities of RBCs of persons with the In(Lu) gene are clinically insignificant, as these cells have normal in vivo survival. Such RBCs, however, are susceptible to increased hemolysis in vitro under standard blood banking storage conditions. Individuals of the Lu(a-b-) phenotype, associated with In(Lu), may not be suitable candidates for routine blood donation.

Evaluation of bovine serum albumin preparations and Ficoll addition in capillary tube hemagglutination.

Eighteen commercial bovine serum albumin (BSA) preparations were evaluated for their efficacy in hemagglutination enhancement by the capillary tube method. Their physicochemical variables (pH, conductivity, free fatty acids, total protein, and polymer content) were quantified. The results showed that a BSA preparation which consistently performed well in hemagglutination enhancement contained some albumin polymer and had a low free fatty acid content. We also found that the addition of Ficoll (final concentration of 1.24%) could convert BSA preparations producing mediocre hemagglutination enhancement into good enhancers, provided that these preparations did not have high free fatty acid content. Hence, the addition of Ficoll can obviate the requirement for selecting a polymer-enhanced albumin for use in capillary tube tests.

Anti-Au: the antithetical antibody to anti-Au.

Anti-Au, the first example of the antithetical antibody to anti-Au, was identified in the serum of a blood donor who had been transfused 16 years previously. Au has a gene frequency of 0.4326 in an American black population and 0.2994 in a southern English donor population. The expression of Au is suppressed by In(Lu). XS2 also suppresses Auberger antigen expression.

Bgb expression in relation to the HLA-B17 antigen splits Bw57 and Bw58 and the cross-reactions of anti-Bgb antibodies.

A substantial number of individuals typed as HLA-B17 do not have Bgb. To determine whether or not this discrepancy reflects genetic or ethnic group differences or the influence of B17 antigen subtypes, a large number of unrelated and related B17 individuals from the Caucasian, Hispanic, Black and Chinese ethnic groups were tested in parallel for Bgb and Bw57- or Bw58- B17 subtype. Higher Bgb expression was found in association with Bw57, but differences in expression of Bgb were also seen in different ethnic groups and in different related individuals carrying the same Bw57 or Bw58 haplotype. Genetic factors other than HLA thus influence the expression of HLa Antigens on red cells. Standard and antiglobulin lymphocytotoxicity tests indicate that all Bgb typing sera contain anti-Bw57 antilymphocyte antibodies and most also contain anti-Bw58 and cross-reacting anti-B12, B15 and/or Bw49 antibodies.

A modified capillary test using 4% ficin.

A capillary technique is described for economical Rh-phenotyping of large numbers of blood samples using diluted antisera and 4% ficin solution. This system is no more time consuming that conventional tube techniques, since enzyme premodification of the cells is not required.

Bga and Bgb correlations with HLA antigens by capillary tube technique.

The manual capillary tube technique, in a series of 114 blood samples collected into CPD, demonstrated Bga on the red blood cells of 93 per cent of the HLA-B7 donors, and Bgb on the red blood of 80 per cent of the HLA-B17 donors. These results compare favorably with reported autoanalyzer studies. Successful results require normal red blood cell-plasma ratios in the samples and avoidance of heparin for collection.

Confirmation of Bg-HLA relationships by antiglobulin microcytotoxicity testing.

Antiglobulin reagents have been reported to increase the sensitivity of lymphocytotoxicity procedures for the detection of HLA antibodies that may affect the survival of transplanted kidneys or cause nonhemolytic transfusion reactions. This paper describes how such a procedure may also be used to demonstrate the presence of specific HLA antibodies in sera containing anti-Bg antibodies but lacking HLA antibodies that can be detected by conventional procedures. With the use of more sensitive procedures for the detection of both anti-Bg and HLA antibodies, studies of the relationship between specific HLA and Bg antigens can be extended, and the genetics of the expression of the Bg antigens can more easily be studied.

Rapid testing of ficinized cells in capillary tubes.

A technique is described for capillary tube testing using small amounts with cell rapidly treated with a 4% ficin solution. This test aids antibody identification and cell screening.

Capillary tube testing and enhancement with 30% Albumin.

Capillary tube methods are reviewed and modifications with albumin are described with emphasis on detection of antigens in the major red cell systems and in HL-A and related systems using red cell suspension.