Lymphocyte immunotherapy in the treatment of recurrent miscarriage: systematic review and meta-analysis.

PURPOSE: Recurrent miscarriage (RM) affects up to 2-3% of couples of reproductive age. There are several causes for this condition, including immunologic. The embryo is considered an allograft, subject to the rejection mechanisms of the maternal immune system. Immunotherapy involving immunization with lymphocytes is considered in cases of idiopathic RM. However, there is still no consensus regarding the efficacy and safety of this therapy. METHODS: This systematic review and meta-analysis evaluated the data available in the literature regarding the efficacy and safety of the use of immunotherapy with lymphocytes in couples with history of RM. Searches in PubMed/Medline, SCOPUS, and Cochrane Library databases were conducted, using the following keywords: "recurrent miscarriage," "lymphocyte immunotherapy," and "meta-analysis." Statistical analyses were performed using Review Manager 5.3 (RevMan), version 5.3. RESULTS: Six published meta-analysis were retrieved; two found no improvements in the rate of live births after the use of immunization with lymphocytes in the treatment of RM, and four found a beneficial effect of the use of immunotherapy with lymphocytes in cases of RM, with significant improvements in the rate of live births. CONCLUSION: Data available in the literature supports the efficacy and safety of immunotherapy with lymphocytes in cases of RM without an identified cause.