Diagnostico imunologico e efeito de imunizações com linfocitos em pacientes com aborto espontaneo recorrente

AUTOR(ES)
DATA DE PUBLICAÇÃO

1998

RESUMO

t: Pregnancy can be considered as a very successful all graft, but the underlying mechanism is not yet completely understood. HLA all tigens compatibility is very important in c1inic transplant due to their all ore cognition by immune system. Nevertheless, genetic differences between maternal and paternal HLA antigens seem to be an important factor for implantation and development of the concept. Such differences lead to immune active responses but, at same time, they help the development of tolerant responses, important to embryo acceptance. So, couples sharing HLA antigens are more subjected to Recurrent Spontaneous Abortion (RSA). As the fetus can be considered a half-all genetic graft, the patient s previous immunization with husband s lymphocytes could be helpful, since it could induce, in patient sera, the arising of both citotoxic antibodies and mixed Lymphocyte culture (MLC) blocking factors, both against husband s . antigens. Those factors have been seen as important for the normal pregnancies and reflect the immune tolerant status of the pregnant women. Hence, the aims of this study was: (1) to examine the HLA compatibility degree in 111 RSA couples and in 161 fertile couples; (2) to define the incidenceofcitotoxic antibodies against husband s lymphocytes (cross match assay) and MLC blocking factors in 291 RSA patients serum; (3) to verify the changes in previous cited factors ill 178 RSA patients submitted to immune therapy. The therapy consisted of 2 to 6 intradermal inoculations, every four weeks, containing 80 X 106 husband or husband plus unrelated donor mononuc1ear cells; (4) to evaluate the relevance of cytotoxic antibodies and MLC blocking factors in 101 cases of pregnancy outcome. We have found that, in our own population, the number of shared HLA antigens was greater in RSA couples than in normal fertile couples. Additional1y, cytotoxic antibodies and MCL blocking factors were found in low frequency (around 12%) in RSA patients. The immune therapy induced the development aft antibodies against husband s lymphocytes in 84,5% of the cases, as well as MCL blocking factors in 71,5% aft the cases, most of them being not specific to husband s lymphocyte responses. Citotoxic antibodies also reacted against to the cross reacting HLA antigens group bin addition to the husband HLA c1ass I antigens, in 52 % of the patients. The miscarriage incidence fell down to 25,7% with the immunization. But the use of cross match and MLC inhibition assays were found to be a limited value in predicting the pregnancy outcome. We did not find significant differences between term and abortion groups concerning these two factors. Since most of the 17 patients of fertile control group studied were in a 12-week-period of pregnancy, it was difficult to evaluate the direct effects of the blocking factors in sera. It is possible that those factors could be absorbed in the fetus-placenta compartment. Where they could contribute to down regulating HLA molecules and with the help of cytokine profile TH2 could induce the immune tolerance to fetal antigens. So, there is a need for an additional in vitro functional test that gives a qualitative assessment of immunotolerant status before pregnancy establishment. This would enable the clinidian to predict the need of additional immunizations for any particular patient. The results suggest an important aid of immunotherapy in the RSA treatment. However, the assays used in this study resulted in a poor predictive test of miscarriage. Nevertheless the cross match and MCL inhibition tests could be used as a first step for monitoring patients who had undergone immune therapy. The couple HLA typing could help define the inclusion or not of unrelated donor in immunizatioti protocols

ASSUNTO(S)

aborto imunologia auto-anticorpos antigenos de histocompatibilidade hla imunização

ACESSO AO ARTIGO

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