Investigation of the expression levels of tam receptor kinases and ligands in unexplained recurrent pregnancy loss

Objective: The role of immunological, genetic and hematological factors in RPL is known. The etiology of unexplained RPL (URPL), which accounts for 50% of RPL, is unknown. Immunological balance is important in the continuity of pregnancy. Inflammation and phagocytosis are regulated via TAM receptor kinase (TYRO3, AXL, MERTK) and ligands (GAS6 and PROS1). Since we think that TAM receptors and ligands may be effective in URPL, We hypothesized that "the expression levels of TAM receptor kinases and ligands in URPL differ from normal pregnancies in chorionic villus and decidua". We aimed to approach the etiology of URPL by comparing mRNA and protein expressions of TAM receptor kinases and ligands in samples of URPL, voluntary terminated pregnancy (TP) who didn't have spontaneous pregnancy loss and endometrium (KE) groups. Method: The groups were formed as (1) URPL (n: 5), (2) TP (n: 6) and (3) KE groups (n: 6). In groups 1 and 2, decidua and chorionic villus materials were separated under a steriomicroscope. The AXL, MERTK, TYRO3, GAS6 and PROS 1 levels of the samples were analyzed by immunohistochemistry, immunoblot and QPCR methods. Results: In healthy pregnancy, increase in TAM receptors, decrease in GAS6 ligand, no significant change in PROS1 was detected. Expression of receptors and ligands in URPL were increased. Conclusion: In TP and URPL, TAM receptors and ligands had differences in expression in decidua and chorionic villus. We believe that these receptors limit ligands in gestation and inhibit excessive phagocytotic activity and modulate immunological cells, contributing to the prevention of rejection of the semiallogenic fetus. Increased receptor and ligand in URPL increased phagocytic activity due to death and inhibited inflammation, thus preventing maternal tissue damage. Key words: Unexplained Recurrent Pregnancy Loss, AXL, MERTK, TYRO3, GAS6, PROS1