Impact of IL-35 and presepsin on immunological, hematological, and biochemical parameters in COVID-19 patients

Immune-inflammatory responses appear to play a key role in severe SARS-CoV-2 infections. Interleukin-35 (IL-35) and presepsin (PSN) are inhibitory cytokine and pro-inflammatory interleukin, which play a crucial role in the immune system modulation, respectively. Therefore, the study of IL-35 and PSN interaction with other parameters may be critical for managing patients with COVID-19.

A total of 125 severe/critical COVID-19 patients and 60 healthy persons as a control group were enrolled in this work. These patients were admitted to Marjan medical city and Al-Sadeq hospital in Iraq during February to August 2022 and diagnosed as severe cases depending on the SpO2 percentage according to the guidelines released by the National Health World. Anti- and pro-inflammatory cytokines (IL-35 and PSN) were detected by ELISA technique.

Presepsin showed a positive correlation with admission to the respiratory care unit (RCU) (r= .022, p= .011). A negative correlation was found between presepsin and C- reactive protein (CRP) (r= .21, p= .018). Both PSN and IL-35 in biochemical tests showed a positive strong effect on glucose levels in COVID-19 patients (r= .234, p= .008 and r= .241, p= .007, respectively). IL-35 had a positive impact on alkaline phosphatase (ALP) (r= .28, p= .002). Hemoglobin (Hb) level showed a positive correlation with presepsin (r= .2, p= .02).

This study confirms the growing evidence showing the direct role of regulatory pro-inflammatory cytokines in the development and control of COVID-19 through the interaction with other parameters.