Autoantibodies, alloantibodies and reproductive success

Adverse drug reactions following lymphocyte immunotherapy for the treatment of infertility: A retrospective study

AIM

Unexplained infertility is a major burden for couples who want to have children. Lymphocyte immunotherapy (LIT) could be a therapeutic help for these couples. Although LIT has been carried out for decades, the data on the success of therapy are still controversial and there is hardly information on possible adverse drug reactions.

METHODS

In this study, we used a questionnaire to determine the frequency of local and systemic adverse drug reactions in our patients who were treated with LIT between 2017 and 2020 (n = 302). In addition, we asked about pregnancies and/or live births after LIT in a 2-year follow-up (n = 140).

RESULTS

Most of the patients reported the occurrence of mild local adverse drug reactions in a period of less than 4 weeks: Over 75% reported moderate erythema, itching or swelling, over 10% erythema, itching or swelling as more pronounced adverse drug reaction. Blistering was specified in 10% of the cases. Serious adverse drug reactions or adverse events were not described. In the follow-up, 69% of our patients stated a pregnancy after LIT, and 50% a life birth.

CONCLUSIONS

Overall, LIT represents a well-tolerated therapy for couples with unexplained infertility, however, more evidence is needed on the benefits.

Active Immunisation with Partner Lymphocytes in Female Patients Who Want to Become Pregnant - Current Status

Around 1 – 3% of all couples who try to have a child are affected by recurrent miscarriage. According to the WHO, recurrent miscarriage is defined as the occurrence of three or more consecutive miscarriages up to the 20th week of pregnancy. There are various causes of recurrent miscarriage; in many cases, the causes remain unclear, with the result that immunological factors are one of the possible causes discussed. For the motherʼs immune system, the embryo represents a semi-allogeneic transplant, as half of the embryoʼs genes are of paternal origin. In place of a conventional immune response, the embryo induces a secondary protection mechanism, which contributes to the successful implantation. When performing immunisation with partner lymphocytes, the patient receives an intradermal injection of her partnerʼs prepared lymphocytes into the volar side of the forearm in order to induce immunomodulation with a consequently increased rate of pregnancy and live birth. A prerequisite for this procedure is that all other possible causes of sterility have been ruled out in advance. Due to the highly heterogeneous nature of the data, a significant benefit as a result of the immunisation cannot yet be clearly proven. However, there are signs that the therapy may be effective when using lymphocytes that have been extracted as short a time beforehand as possible. Overall, the treatment represents a safe, low-risk procedure. Following a detailed informative discussion with the couple regarding the chances of success and following a detailed review of the indication and contraindications, immunisation with partner lymphocytes can be discussed with the couple on a case-by-case basis – provided that all other possible causes of sterility have been ruled out in advance.

Immunological prevention of spontaneous early embryo resorption is mediated by non-specific immunosimulation

PROBLEM

Spontaneous early embryo resorption following implantation occurs in many species, but little is known regarding the causes or the prevention of early pregnancy failure. Embryo and fetal loss have widely been assumed to be due to maternal allospecific immune rejection. Alloimmunization therapy with paternal tissues has been successfully used in human and murine pregnancies to prevent early embryo demise. The mechanisms of this treatment have been assumed to be the induction of antigen specific, fetal "graft" enhancing antibodies and suppressor cells. The purpose of this study was to investigate the validity of this assumption.

METHOD

To investigate these general assumptions, female CBA/J mice were immunized with either specific or nonspecific antigens prior to mating with DBA/2 or Balb/c males. Further, a model system for the study of bacterial lipopolysaccharide (LPS) induced abortion was used to demonstrate the nature of antigen specific immune protection against abortion.

RESULTS

Whereas the administration of 1 microgram of LPS to CFW female x CFW male pregnant mice on day 7 of gestation induced complete fetal resorption, prior immunization with 20 micrograms of LPS completely prevented LPS induced abortion as long as the anti-LPS antibody titers remained above a threshold value of about 1/500. Therefore, early embryo loss could be induced by a bacterial infection and could be prevented by appropriate immunity to abortogenic factors. However, due to the short half-life of IgM antibodies, immunity to LPS was short-lived and the protective effect of LPS immunization against LPS induced abortion waned after 5 wk. Through the use of the CBA/J female x DBA/2 male model system to study spontaneous early embryo loss, previous vaccination of CBA/J female mice with Balb/c spleen cells expressing paternal MHC antigens, complete Freund's adjuvant (CFA) or LPS, all decreased the incidence of spontaneous resorption in subsequent pregnancies. Similarly, a previous mating with a Balb/c male prevented spontaneous embryo loss for a period of up to 6 wk. However, none of the immunotherapeutic vaccinations or matings had a permanent effect on CBA/J female x DBA/2 male embryo survival, which one would have expected if specific immune mediators were involved.

CONCLUSION

The results of this study indicated that the decrease in the incidence of spontaneous embryo resorption following alloimmunization was more likely to be due to nonspecific immunomodulatory effects on the immune system of the female mice, as opposed to specific antipaternal immunity. This may, in part, explain the placebo effects observed for alloimmunization therapy for human habitual pregnancy loss. The relevance of these results to the development of immunotherapy strategies for the prevention of habitual abortion is discussed.