Dynamics of ST2 biomarker level under the influence of spaceflight and landing factors

The dynamics of the level of the biological risk marker for heart failure and cardiophibrosis ST2 under the influence of factors of space flight and landing was analyzed. Plasma samples obtained from the venous blood of 14 cosmonauts who had flown on the Russian segment of the ISS were studied. The biological samples collected before the flight, on the first and the seventh day after landing were analyzed by means of commercial test-kit "Critical Diagnostics Presage® ST2 Assay" (USA) by enzyme immunoassay (ELISA). Analysis of variance analysis of ST2 protein levels in all cosmonauts revealed a significant increase in its concentration on the first day after the flight relative to individual and group average background levels (p-value 0.05). On the 7th day of the recovery period the ST2 protein content decreased, approaching the background value. The obtained results indicate a transient mechanical deformation of myocardium during landing and an increased risk of myocardiofibrosis in the distant period of re-adaptation after space flight.