[Current program of in-vitro fertilization at the Erasmus Hospital: initial results and original ethical aspects]. / Nouveau programme de fécondation in vitro à l'hôpital Erasme: premiers résultats et aspects éthiques originaux.

The clinical results including all in vitro fertilization (IVF) cycles with oocyte pick-up in 1990 are presented. Different types of treatment including classical IVF and embryo transfer, laparoscopic replacement of zygotes in the fallopian tube (ZIFT), IVF with donor sperm (IVF-D), cross fertilization test, embryo freezing, oocyte donation and IVF with epididymal sperm were performed. The total pregnancy rate obtained reaches 38% per oocyte pick-up, 30% of clinical pregnancies (including 4 pregnancies obtained with frozen and thawed embryos). The anticipated "Take Home Baby Rate" will be around 25% per oocyte pick-up, 26 of these 40 pregnancies being today over 20 weeks of gestation. Particular ethical aspects of the program are presented: a study on couple's attitudes regarding embryo freezing as well as the final destination of possibly remaining supernumerary embryos will stress the importance of a precise clear decision on that matter before entering IVF treatment. Indeed the couple's idea on embryo destiny were very precise but also very different. The oocyte donation program has the originality of preserving the donor's anonymity by exchanging the donors recruited by the patients. It will be stressed that this kind of approach combines higher pregnancy chances for the patients, respect of ethical principles linked to gamete donation and gives satisfaction to the patients. The global normalized pregnancy cumulative curve shows that 60% of the couples entering IVF treatment will obtain a child within the first three pick-up cycles.

Increased expression of Ia antigens on B cells after neonatal induction of lymphoid chimerism in mice: role of interleukin 4.

BALB/c mice rendered chimeric at birth by injection of 10(8) (A/J X BALB/c)F1 spleen cells develop a lupus-like autoimmune disease linked to the activation of donor B cells by host T cells. As in vitro studies previously indicated that interleukin 4 (IL4) was a mediator of the interactions between T and B cells, we analyzed the intensity of Ia antigen expression on B cells of chimeric mice. Flow cytometric analysis with anti-Ia monoclonal antibodies (mAb) revealed that B cells from spleens and lymph nodes of 2-week-old chimeric BALB/c mice displayed a two- to threefold increase in membrane Ia antigen expression, this increase still being present in spleens of 30-week-old animals. An increase in Ia antigen expression was also found in the small number of donor B cells detected in spleens and lymph nodes of chimeric mice. IL4 was the major stimulus leading to increased B cell Ia antigen expression, as this phenomenon was substantially prevented by in vivo treatment of chimeric mice with the anti-IL4 11B11 mAb. In vitro experiments revealed that host splenic T cells of chimeric mice, while unable to generate anti-donor cytotoxic T lymphocytes, secreted significant amounts of IL 4 when stimulated in mixed lymphocyte cultures (MLC) with donor alloantigens. This IL4 secretion led to an increased expression of Ia antigens on donor-type F1 B cells present in MLC. No significant increase in Ia antigen expression was found on syngeneic BALB/c B cells co-cultured with T cells from chimeric mice unless A/J B cells were added to the cultures. Taken together, these findings indicate that increased Ia antigen expression on donor B cells is induced by IL4 secreted by anti-donor T cells. IL4 released in this setting also leads to increased Ia antigen expression on host B cells through a bystander effect.

Autoimmunity and glomerulonephritis after neonatal induction of lymphoid chimerism in mice: role of donor B cells and host T cells.

Balb/c mice neonatally injected with semiallogeneic (A/J x Balb/c) F1 or (C57 BL/6 x Balb/c) F1 hybrid spleen cells develop autoantibodies, marked increase in serum levels of IgG1 and IgE, lymphoid hyperplasia, and immune-complex glomerulonephritis. F1 donor B cells play a dominant role in the pathogenesis of this autoimmune disease since B-cell chimerism is required for the occurrence of immunopathology, donor-specific allotype is expressed on serum anti-DNA antibodies, and substantial amounts of donor-derived immunoglobulins are present in the kidney eluate of chimeric mice. In vitro experiments indicate that T cells from diseased Balb/c mice induce activation of F1 donor B cells with secretion of anti-DNA antibodies. These findings suggest that a host-versus-graft reaction between recipient T cells and donor F1 B cells is responsible for the secretion of pathogenic antibodies in this model.