Association between serum levels of GDF-15, suPAR, PIVKA-II, sdLDL and clinical outcomes in hospitalized COVID-19 patients

To quantify the circulating levels of novel serum biomarkers including GDF-15, PIVKA-II, sdLDL, suPAR, and of CRP in hospitalized COVID-19 patients compared with healthy subjects, and to evaluate their association(s) with outcomes in COVID-19. We considered patients with confirmed COVID-19, hospitalized in an Internal Medicine ward. The clinical characteristics were collected, including the number and type of comorbidities. Serum levels of GDF-15, PIVKA-II, suPAR, sdLDL, as well as CRP were measured. As outcomes, we considered Intensive Care Unit (ICU) transfer or death, as well as the length of stay (days) and in-hospital complications. Data were statistically analyzed, as appropriate, and a p value < 0.05 was considered significant. Ninety-three patients and 20 healthy controls were enrolled. COVID-19 patients vs. controls showed higher median levels of GDF-15 (p < 0.0001), PIVKA-II (p < 0.0001) and sdLDL (p = 0.0002), whereas no difference was observed for suPAR. In COVID-19 patients, the most frequent comorbidities were arterial hypertension (62.4%) and cardiovascular disease (30.1%). GDF-15 levels positively correlated with age (r = 0.433, p < 0.0001), and this correlation was confirmed for suPAR (r = 0.308, p = 0.003) and CRP (Rho = 0.40 p < 0.0001), but not for PIVKA-II and sdLDL. Higher GDF-15 levels were associated with a higher number of comorbidities (p = 0.021). The median length of stay was 22 (15; 30) days. During hospitalization, 15 patients (16%) were ICU transferred, and 6 (6.45%) died. GDF-15 serum levels correlated with the length of stay (rho = 0.27 p = 0.010), and were associated with ICU transfer or death (p = 0.003), as well as PIVKA-II (p = 0.038) and CRP (p < 0.001). Moreover, higher GDF-15 and PIVKA-II serum levels were associated with infectious complications (p = 0.008 and p = 0.017, respectively). In this cohort of hospitalized COVID-19 patients, novel inflammatory biomarkers, including GDF-15, suPAR and PIVKA II were associated with some patient's clinical characteristics, complications, and poor outcomes.