Anti-Jka, -C, and -E in a single patient, initially demonstrable only by the manual hexadimethrine bromide (Polybrene) test, with incompatibilities confirmed by 51Cr-labeled red cell studies

Transfusion support for a patient with alloanti-D and the RHD*DV.1 allele

BACKGROUND

Safe blood transfusion is significantly affected by the complex antigen polymorphism and a high proportion of autoantibodies of the Rh blood group system.

THE PATIENT AND METHODS

A male Chinese patient with primary biliary cirrhosis, esophageal and gastric rupture, and bleeding was admitted to our hospital. Blood typing identified that he had serological O and D+ blood groups. Because autoantibody was not detected using routine immediate spin (IS) and indirect antiglobulin test (IAT), he was treated by transfusing D+ red blood cells (RBCs). However, this treatment was ineffective. Thus, manual polybrene test (MPT) and low ionic salt solution indirect antiglobulin test (LISS-IAT) were performed, followed by exon sequencing of the RHD gene.

RESULTS

The patient was confirmed as a DV Type 1 individual by gene sequencing, and had 4+ RhD antigen agglutination. The anti-D in serum and elution could only be detected by MPT (2+ agglutination) and LISS-IAT methods (1+/3+ agglutination). It was presumed that attenuated alloantibody contributed to ineffective RBC transfusion, causing a transient increase in hemoglobin (HGB) before falling back to 50 g/L or even lower within four days.

CONCLUSION

Genotyping helps to support the specificity of detecting autoantibodies and alloantibodies. Combining more serological methods with molecular technology in blood typing is beneficial to improve the safety and effectiveness of blood transfusion.

Immune hemolytic anemia associated with negative routine serology

Immune hemolytic anemia can occur in patients who have no antibodies detectable by routine procedures (direct [DAT] and indirect [IAT] antiglobulin tests). DAT-negative autoimmune hemolytic anemias (AIHAs) represent 5% to 10% of all AIHAs. Three causes have been identified: (1) small numbers of red blood cell (RBC)-bound IgG molecules below the threshold of the DAT; (2) IgA and IgM autoantibodies; and (3) low-affinity autoantibodies. Antibody-independent cytotoxic events caused by natural killer (NK) cells have also been implicated. DATs are sometimes found to be positive when tested by reference laboratories, due to poor technique in reading antiglobulin tests in hospital laboratories. Hemolytic transfusion reactions also can occur when no alloantibodies are detectable by routine procedures. In some cases antibodies can be detected by special serologic procedures (such as the Polybrene test); in other instances phenotypically matched RBCs survive well and a specific antigen can be shown to be involved, suggesting a specificity (like anti-C) that is undetectable by any technique. Antibodies other than to blood group antigens, such as human leukocyte antigen (HLA) antibodies, may sometimes be involved.

Comparison of low ionic diluents for use with the Diamed antiglobulin gel test

Microtube column systems, although widely used in transfusion serology for the detection of red cell antibodies, may not detect weak Fy(a), Jk(a), S and K antibodies. A number of low ionic diluents are used to shorten the incubation time required for red cell antibody detection in the antiglobulin test. However, there are no published reports to show whether these low ionic diluents vary in their ability to detect red cell antibodies using microcolumn detection systems. Three low ionic diluents, Diamed ID-CellStab, Diamed ID-Diluent2 and an in-house produced low ionic strength solution (LISS), were assessed using the Diamed-ID LISS/Coombs microtube column system (in accordance with the manufacturer's instructions), to ascertain whether the choice of diluent influences red cell antibody detection. Two hundred and seventy patient samples were screened for red cell antibodies. The reaction strength was increased in 50% of the samples with detectable red cell antibodies using LISS as the diluent compared with ID-CellStab. Of the 51 red cell antibodies directed against Rhesus, Duffy, Kidd or Kell antigens, 21% reacted more strongly in LISS compared with Diamed ID-CellStab with a difference in grading of > or =1. Minimal disparity was found between ID-Diluent2 and LISS. Biochemical analysis of pH, osmolality, sodium, potassium and phosphate were comparable for ID-CellStab, ID-Diluent2 and LISS. Measurement of conductivity in each low ionic diluent was performed as a measure of ionic strength in the final reactant mix, as the same amount of low ionic diluent was used for each test. The conductivity was 3 x 5 mS cm for LISS and ID-Diluent2, and 5 x 8 mS cm for ID-CellStab; the acceptable range being 3 x 7 +/- 0 x 3 mS cm as cited in the Guidelines for the Blood Transfusion Services in the United Kingdom. This evaluation suggests that ID-CellStab is a suboptimal low ionic diluent for red cell antibody detection using Diamed-ID LISS/Coombs gel cards. The poorer performance of ID-CellStab compared with LISS may be explained by its higher ionic strength.