ポリビニールピロリドン・フィコール混合メジウムの血球凝集反応への応用

抄録

Medium solutions for hemagglutinating tests reported herein have advantages such as potent enhancing effect toward incomplete hemagglutinin, relatively low viscosity and stable colloid conditions.
Details of preparation methods of the media had been previously described. Compositions of the media are as follows:
PF medium—7ml of 30% PVP k30 (pH 7.5), 2.0ml of 25% ficoll, 0.68g imidazole, 0.82g natrium chloride, 0.1g sodium azide, 0.01ml Tween 80, 85ml deionized water and an appropriate quantity of hydrochloric acid to adjust the pH of the mixture to 7.5.
PFP medium—85ml of PF medium, 15ml of 30% PVP k15 (pH 7.5) and 2 to 5g bovine serum albumin (optional).
(1) Serological properties of blood group agglutinins diluted with PF or PFP medium.
The incomplete-agglutinin enhancing effect of PFP medium was weaker than that of PF, but stronger than 20 to 30% bovine serum albumin solution. After mixing with PF or PFP medium, most blood group agglutinins, e. g. anti-D, anti-Le^a and anti-P₁, caused the enhanced hemagglutinating reaction even outside their respective optimal temperatures. Marginally positive Le(a+) and P₁(+) red cells became susceptible to react with corresponding agglutinins to form large sized and firm agglutinates. Owing to these effects, blood group determination due to agglutinin reaction was performed without reading difficulties when the reagents were diluted with PF or PFP medium. The mixture of blood grouping reagent and the PF medium sometimes caused weak agglutination of red cells obtained from persons belonging to uncorresponding groups. This disturbance was supposedly due to either or both (1) enhancement of dormant incomplete hemagglutinin, and/or (2) rouleaux formation. The former type of the nonspecific agglutination was in most cases caused by a kind of incomplete cold hemagglutinin, which persistently remained in normal or immune sera even after overnight storage of whole blood at 5°C. This type of disturbance did not occur after further absorption with red cells. The latter phenomenon was completely inhibited by adoption of the testing techniques in which excessive evaporation from the surface of the reacting mixture was prevented, e. g. tube test and slide test performed in a moist chamber. PFP medium hardly caused nonspecific hemagglutination.
(2) Examples of application of PF and PFP media on blood group serology.
1) Detection of blood group agglutinin activity from electrophoreticaly or chromatographicaly obtained fractions of antisera: Not infrequently, hemagglutinating activities of highly diluted solutions of fractionized serum components could not be detected by means of saline and albumin test or by the tests with enzyme treated red cells. Addition of PF medium to the mixture of the fractionized solution and red cell suspension promoted the agglutinin activity to feasibly determine the distribution of the agglutinin. This technique may be applied to many experiments in place of the Coombs' test.
2) Detection of incomplete hemagglutinins for serological tests of ABO-incompatible pregnancy: Incomplete anti-A, anti-B and anti-C (of ABO) agglutinins in sera of pregnants were strongly enhanced by the addition of 1/3part of PF medium into the reacting mixture of tested sera and red cell suspension. Titers obtained by this test were 4 to 8 times higher than those by enzyme treatment test; whereas the sensitivity of PFP medium test was intermediate of the enzyme treatment test and albumin test.
3) PF medium test for substitution of the indirect Coombs' test: Selected were 6 blood grouping reagents for which the use of Coombs' test was directed by the manufacturers. One drop each of the reagent, 3% red cell suspension and PF medium were mixed, allowed to stand for 20min at 25°C and centrifuged for 1min at 1.5000 r. p. m. Four of the antisera properly caused positive reaction of red c