Summary
Aim of the thesis is to evaluate the significance of elution test results in the analysis of the causes of a positive direct antiglobulin test (DAT).
Research material and methodology. Blood samples from 63 patients with positive DAT were examined in the research. Elution tests were expected to detect immune (auto or allo) antibodies covering patients’ erythrocytes in vivo. The research consisted of three main stages: 1) selection of positive DAT samples; 2) performing an elution test on positive DAT samples; 3) performing IAT (In direct antiglobulin test) after the elution test.
Results. After the elution test in 63 patients, it was determined that 32 (50.79%) eluates were reactive and 31 (49.21%) were non-reactive. After testing the immune antibodies in the reactive eluates, 8 (25%) alloantibodies and 24 (75%) autoantibodies were identified. The most commonly detected alloantibodies were directed against the Rhesus (42%) blood group antigen system, of which the majority was anti-E (34%). When patients were divided into weakly and strongly positive DAT groups, a statistically significant relationship was found between the Coombs reaction strength groups and the results in the eluate groups (Kramer binding strength coefficient was 0.27. Chi2=4.59, p=0.032). The C3d strength of the complement component C3 fragment did not differ statistically significantly between the reactive and non-reactive eluate groups (Fisher p=1.000). Analysis of the reactive eluate group in which immune antibodies were detected with DAT strength re vealed no statistically significant relationship between immune antibodies and Coombs reaction strength (Fisher p=0.218).
Conclusions. It was found that reactive eluates containing immune antibodies are more frequently detected in the case of strongly positive DAT, and weakly positive Coombs reaction is characteristic of non-reactive eluates (Kramer binding strength coefficient is 0,27. Chi2=4.59, p=0.032). The C3d strength of the complement component C3 fragment did not differ statistically significantly between the reactive and non-reactive eluate groups (Fisher p=1.000). The C3d strength of the complement component C3 fragment does not affect the obtained reactive and non-reactive reaction of the eluate. When the association of immune antibodies identified in the reactive eluate group with the strength of DAT was assessed, no statistically significant association was found (Fisher p=0.218). The type of immune antibodies identified in the reactive eluates did not depend on the strength of the DAT.
