Association of Serum Krebs von den Lungen-6 (KL-6) Levels and Disease Severity in Patients Hospitalized with COVID-19.

OBJECTIVE

We aimed to evaluate Krebs von den Lungen-6 (KL-6) as a possible biomarker in determining disease severity in patients with moderate and severe COVID-19.

MATERIALS AND METHODS

This cross-sectional study included moderate or severe COVID-19 patients; critically ill patients who were followed up in the intensive care unit were not included. KL-6 level and routine laboratory test measurements were performed on the first day of admission. The patients were also categorized according to their hyperinflammatory state.

RESULTS

The study included 92 patients, 56 (61%) women. The National Institutes of Health (NIH) score was 2 in 52.2% of the patients and 3 in 47.8%. KL-6 levels did not significantly differ in disease severity (NIH score 2 vs. 3; =0.15). Median KL-6 values were 52.7 (29.1) in patients with <2 COVID-19 hyperinflammatory syndrome score (cHIS) and 61.7 (32.2) in patients with cHIS ≥ 2 (= 0.077). KL-6 values tended to be higher among the patients with lower lymphocyte counts, but the difference was not statistically significant (<1000 mm³/L =0.006 and higher cHIS scores ≥2 =0.07). KL-6 values were also higher in the patients with diabetes mellitus compared to the remaining patients ( =0.036).

CONCLUSION

There was no significant association between the serum KL-6 measured at admission and the severity of COVID-19.