Roles of soluble TAM receptors, ligands for these receptors, and shedding enzymes in patients with acute pancreatitis

The goal of the study was to measure the plasma levels of soluble TAM receptors (sTAMRs: Tyro3, Axl and Mer), growth arrest-specific 6 (Gas6), free-PROS1 (Protein S), and C4bp-protein and two disintegrin metallopeptidase domains (ADAM 10 and 17) in patients with acute pancreatitis (AP).
The subjects were 56 patients, including 14 cases of severe AP and 42 cases of mild AP, and 20 healthy normal controls. Plasma levels of the three sTAMRs, Gas6, free PROS1 and C4bp-protein, and two ADAMs were measured using ELISA kits.
The levels of the sTAMRs and ADAM10 and 17 increased markedly with greater severity of AP. Three sTAMRs increase rate became the order of sTyro3, sMer and sAxl, while ADAM10 was higher than ADAM17. The platelet count and PROS1 significantly decreased in AP but there are differences between C4bp-protein, but these are not significant. sTAMRs levels increased in the early stage in almost all AP patients, but then gradually normalized. However, sTAMRs in non-survivors increased again in the late stage. The fluctuations of ligands (Gas6 and free-PROS1) levels in AP patients showed progress like three sTAMRs.　The correlation coefficients of sTAMRs with ligands were stronger for free-PROS1 in non-survivors and patients with severe AP, whereas Gas6 was more strongly correlated with sTAMRs in patients with mild AP.
Marked increases of sTAMRs and ADAMs were found with increased severity of AP. Gas6 and free-PROS1 in the TAM system may have complementary roles in local and systemic lesions, respectively.