Peritoneal ceils of anemic donors enriched with macrophages at the expense of Tcell lysis using anti-Thy-1.2 monoclonal antibodies are capable of triggering various routes of terminal erythroid differentiation characteristic of stress erythropoiesis during their adoptive transfer to normal syngeneic recipients. Stimulation of the proliferation of polychromatophilic erythroblasts and initiation of mitoses in oxyphilic erythroblasts are regulated by interacting T ceUs and macrophages, and the "reserve erythropoiesis" mainly by macrophages. Key Words: stress erythropoiesis; peritoneal cells; reserve erythropoiesis; blood lossIn mammals with severe anemias the erythroid precursors, on reaching the terminal stages, form red ceils as a result of terminal differentiation by various routes. One of these routes, "reserve erythropoiesis," is an emergency route of accelerated differentiation of ceils providing for the survival of the organism during the early periods after massive blood loss. It consists in the omission of severn terminal stages and the rapid release of morphologically immature cells into the blood [2,3,[6][7][8]. A transito13" increase in the content of basophilic erythroblasts (BE) in the bone marrow paralleled by a decrease of their mitotic activity may be considered as a bone marrow marker of "reserve erythropoiesis" [3,7]. Moreover, blood loss enhances polychromatophilic erythroblasts (PE) amplification and initiates mitoses in oxyphilic erythroblasts (OE), which normally almost never divide [1,3].

The article provides a literature review about RHD and RHCE polymorphisms which encode different RhD and RhC antigen variants. The data about genes RHD and RHCE polymorphisms, RhD weak types, RhD partial types and RhC variants in Russians is presented for the first time. The molecular and serological characteristics of rare RhD and RhC antigens are summarized. The role of serological and molecular methods in Rhesus system antigens identifying is shown.

The weak D antigen could be serologically identified in 96.8% of cases. When testing for weak D, particular attention should be given to people with the D-negative phenotype who had the C or E antigens. Our investigations conducted for the first time in Russia will be able to improve the immunological safety of red blood cell-containing medium transfusions for patients.

Background. Rhesus phenotype has been determined in 404 persons which have problems with blood groups identification. Genetic typing of antigen RhD variants was performed in 73 individuals. Objective of the work was to give molecular and serological characteristics of the antigen RhD weak types.Materials and methods. Method of rhesus phenotype determination in direct agglutination test on plane by using of anti-D, anti-C, anti-c, anti-Cw, anti-E and anti-e monoclonal antibodies; gel method of rhesus phenotype determination; methods of genetic typing of RhD; methods of antigen RhD determination in the classic indirect antiglobulin test and in the gel indirect antiglobulin test; method of antigen RhD determination in the saline agglutination test.Results. Serological methods identified 73 red blood samples with the weakened expression of RhD antigen. Molecular methods showed the reasons of weakness of antigen expression. Three RHD*D weak types which are common in Russians (RHD*D weak type 1–3) were identified and for the first time 3 types were found – RHD*D weak type 67, RHD(G255R) and RHD(JVS5-38del4). Serological characteristic of RhD weak types was given. It was shown that combined using of monoclonal antibodies in direct agglutination test and in gel is the most effective serological method of the antigen variants detection. Red blood cells with weak RhD antigens can be recognized by weakness or absence of agglutination with monoclonal antibodies on plane if agglutination in gel was 3+4+.Conclusion. Concrete weak RhD variants can be determined only by genetic typing. Serologically weak antigen variants can be detected by using of at least two series of monoclonal antibodies or by using of two different methods (it is preferable).