RESUMEN
Immunohematological procedures are based on the interaction between red cell antigens and specific antibodies. Evidence for the in vitro formation of an antigen-antibody reaction is traditionally based on the visualization of agglutinates or the presence of hemolysis. The conventional tube test with an indirect antiglobulin test is considered as the gold standard for detecting hemagglutination. Currently, commercial gel tests are used to detect hemagglutination. We aimed to evaluate our in-house developed gel (K-Med gel) against the conventional tube and commercial gel tests. To evaluate the specific gels, samples from 500 patients were tested for ABO and Rh(D) blood group and samples from 500 donated blood were tested for C, c, D, E and e antigens. The sensitivity of the neutral and antiglobulin gels were tested and compared to the commercial gels and the tube tests. The K-Med gel was used for antibody screening on 531 samples. The K-Med specific gel was able to identify ABO and Rh (CcDEe) blood groups as same results as the tube test did. Similarly, the sensitivity of the neutral and antiglobulin K-Med gel was as good as the commercial gels but higher than the tube method. In antibody screening test, 33 of 531 samples were positive. The gel test was able to detect clinically significant antibodies more frequently than the tube method (3 samples). While the tube method was able to detect non clinical significance antibodies more frequently than the gel test (4 samples). In conclusion, K-Med gel is recommended to be used for ABO and Rh blood grouping instead of using the tube method. The neutral and antiglobulin gel were able to detect the antibody-antigen reaction on red blood cells, especially the clinically significant antibodies. The K-Med gel can be applied for micro-plate system, which makes it easier to perform and less time consuming. It is also therefore suitable for routine testing in high work load laboratories.
RESUMEN
A study on immune response to Cryptococcus neoformans antigens was done in rabbits. Three different doses of encapsulated C. neoformans antigens, 1.5x107, 1.5x108 and 1.5x109 cells/milliliter respectively, were injected intravenously via ear vein. Results showed that the concentration of 1.5x108 cells/milliliter stimulated high agglutination titers of antibody i.e., 1024 in one rabbit and 32768 in the other. For comparison, the titer of antiserum obtained from rabbits immunized with 1.5x107 cells/milliliter did not exceed 64, while the dose of 1.5x109 cells/milliliter killed rabbits. Results suggested that a high quantity of anti-C. neoformans antiserum could be prepared in rabbits. This antiserum would be an important reagent in the development of the serological test kit for Cryptococcal diagnosis.KEY WORD : Cryptococcus neoformans, Antibody response.
RESUMEN
Human Leukocyte Antigen (HLA) is an antigen system found on surface of white blood cells and body tissues. Their functions are related to immune response to recognize and eliminate foreign antigens. Many diseases are associated with HLA alleles, especially HLA-B*27 which is strongly associated with ankylosing spondylitis (AS). In this study, the high resolution PCR-SSP has been developed to detect HLA-B*27 by 2 primer mixtures (Sc1 and Sc2). The HLA-B*27 group specific primers have been tested in 846 unrelated healthy northeastern Thais (NET), 338 northern Thais (NT), 271 Karens and 308 Burmese. Sixty-three NET (7.4 %), 24 NT (7.1 %), 5 Karens (1.8 %), and 12 Burmese (3.9 %) were positive for HLA-B*27. This study established a simple technology for HLA-B*27 testing and provided basic information for assessing the risk of AS and further study in disease associations.