Circulating syndecans during critical illness

Circulating syndecans are proposed to be markers of glycocalyx degradation and previous investigations have found higher plasma levels of syndecan‐1 among patients with different pathological conditions. We wanted to investigate if levels of other syndecans (‐2,‐3 and ‐4) are altered during critical illness and compare the levels to syndecan‐1. In 137 consecutive intensive care unit (ICU) patients with sepsis, cardiac arrest, gastrointestinal bleeding, intoxication or trauma, plasma levels of syndecan‐1, ‐2, ‐3 and ‐4 were measured using ELISA. Syndecan‐1 and syndecan‐3 levels were similar among the different ICU patient groups but higher than controls. No differences in plasma levels of syndecan‐2 or syndecan‐4 were found neither among the different ICU patient groups nor compared to controls. All syndecans showed an association with mortality and the levels of syndecan‐1 and ‐3 and correlated with each other. The results indicate that syndecan release is triggered by the physiological stress of critical illness in general and involves several subtypes such as syndecan‐1 and syndecan‐3.