Object of study: Phenomenon of antigenic mimicry in serologic diagnosis of AIDS, false-positive reactions in detection of anti-HIV antibodies. Aim of study: To assess the contribution of antigenic mimicry to the false-positive reactions in serologic diagnosis of HIV infection and to elaborate the methodological approaches allowing for the improvement of diagnostic efficacy. Methods: Complex of microbiological, virological, molecular biological, biochemical, immunological and statistical methods. Theoretical and practical results: The theoretical generalization and the practical reasoning of the topical problem - improvement of serological diagnosis of HIV infection owing to the delineation of the contribution of antigenic mimicry to the false-positive reactions in serologic diagnosis of HIV applied to the use of immunoenzyme test-systems - has been presented. Novel: the false-positive results of anti-HIV antibody detection in the patients with diabetes, tuberculosis, in the persons vaccinated against the rabies, in pregnant women and sometimes in blood donors have been shown to result from cross reactions between the antibodies in false-positive sera and HIV proteins contained in diagnostic test-system. Carbohydrate-containing biopolymers - the mimicrins were isolated from bacteria, fungi, toxins and lymphoid cells. These mimicrins have been shown to share several cross-reacting determinants. Moreover, they are cross-reacting with the peptides of HIV, herpes virus, rubella virus, viruses of hepatitis B and C, papilloma virus. Mimicrins of various origins are glycoproteins with different chemical composition. They are partially related to lectins and heat-shock proteins. Degree of introduction: the methods for detecting antibodies against various HIV serotypes have been elaborated. Based on synthetic oligopeptides, confirmation test-system has been developed. The efficacy of the serologic diagnosis of HIV infection has been attained due to inhibition of non-specific reactions. With this aim in view, anti-mimicrin antibodies and modified Gag of HIV-1 are applied, which is of high practical importance. The availability for implementation: The methods and the draft laboratory operating procedure for mimicrin isolation have been elaborated. The isolated mimicrin are used for producing anti-mimicrin antibodies applied for blocking non-specific interactions in immunoenzyme test systems. For the first time in Ukraine, the test-system for HIV serotyping has been developed. This test-system is protected by the patent for the utility model. The draft laboratory operating procedure for manufacture of such test-system has been drawn up. Taking into account the phenomenon of molecular mimicry and our recommendations, scientific-and-production company Diaprof-Med has engineered gene construct for producing recombinant Gag protein of HIV-1 lacking several amino acid sequences shared with that in proteins of mycobacteria that allows for increasing the specificity of immunoenzyme test systems for the detection of anti-HIV antibodies up to 99.7 %. The recombinant Gag protein of HIV-1 and test-systems containing this protein are protected by the patents for the invention and the utility model. In cases of the false results in diagnosing HIV infection, the expediency of using immunoblot and test-system for HIV serotyping with the aim of confirming the presence or the absence of HIV infection has been proved. Publications: "Practical guide on immunoenzyme analysis" and "Serological diagnosis of HIV infection. Practical guide", where in the possible reasons of false-positive reactions are considered. Sphere of the use: medicine, veterinary, virology.
