Examination of the clinical effects of copper (CU) level inintensive care COVİD-19 patients

Copper exhibits potent antibacterial, antifungal, antiviral, and anti-inflammatory effects by supporting the host's immune response. Our study aimed to investigate the clinical and prognostic effects of copper and ceruloplasmin levels in critically ill patients with confirmed or suspected COVID-19 in the ICU. After obtaining ethical committee approval, adult patients admitted to the Hacettepe University Anesthesiology Intensive Care Unit from November 15, 2021, to June 15, 2022, were included. Patients were divided into two groups: COVID-19 positive and negative. The criteria for the COVID-19 negative group included four consecutive negative PCR results and symptoms explainable by other clinical conditions. Demographic data, comorbidities, admission symptoms, COVID-19 PCR results, APACHE-II and SOFA scores, length of stay, laboratory results, copper and ceruloplasmin levels at admission, mechanical ventilation requirements, vasopressor needs, and mortality data were prospectively recorded. The normal serum range for copper was determined as 13.3-26.7 μmol/L and for ceruloplasmin as 22-58 mg/dL. The median (range) age of all patients (N=107) was 73 years (20-91), with 60 (56%) females and 47 (44%) males. Fifty-seven patients were COVID-19 positive, and fifty were negative. The median copper and ceruloplasmin levels for the COVID-19 positive group were 22.44 μmol/L (4.15-42.26) and 44.3 mg/dL (23.2-87), respectively, while for the COVID-19 negative group, they were 23.185 μmol/L (11.23-39.9) and 45 mg/dL (20.6-82.2) (p=0.62 and p=0.753). No significant relationship was found between copper and ceruloplasmin levels and gender, statin and food supplement usage, malnutrition, oxygen, mechanical ventilation, vasopressor and renal replacement therapy needs, ICU and hospital length of stay, and mortality. Four (4%) patients had low copper levels, 80 (75%) had normal levels, and 23 (21%) had high levels. The high copper group showed significantly higher GGT (gamma glutamyl transferase) levels (59(13-315) vs. 39(8-369), p=0.049) and leukocyte counts (9.7(4.8-37.4) vs. 8.25(1.6-29.2) (x103 /microL) ( p=0.028) compared to the normal copper group, but there was no significant impact on mechanical ventilation, vasopressor and renal replacement therapy needs, ICU and hospital length of stay, and mortality. In conclusion, copper levels measured at ICU admission did not significantly impact clinical outcomes in critically ill patients with confirmed or suspected COVID-19. However, given that one-fifth of critical patients had high copper levels, monitoring copper levels at admission and careful observation for toxicity might be important in critically ill patients.