Correlation between serum C-reactive protein and neutrophil with myeloperoxidase enzyme in post mortem core biopsy of lung in patients with critical COVID-19 pneumonia at a tertiary hospital, Indonesia.

BACKGROUND

Coronavirus disease 2019 (COVID-19) is a global pandemic with a high mortality rate and is associated with cytokine storms due to excessive immune response. Serum C-reactive protein (CRP) and neutrophils are markers of inflammation. Myeloperoxidase (MPO) is an important part of neutrophil extracellular traps (NETs) that accumulate in inflamed lung tissue. This study aims to analyze the correlation between serum CRP and neutrophil with MPO enzyme in post mortem core biopsy of lung.

METHODS

This was an observational analytic with a retrospective cohort design in patients who died because of a critical COVID-19 pneumonia. Core biopsy of lung tissue was carried out a maximum of 2 h after the patient died. The correlation between serum CRP, serum neutrophils, and lung tissue MPO enzymes was analyzed statistically.

RESULTS

The majority of lung tissue MPO enzymes was scoring 1 (43.6 %), the characteristics of lung tissue MPO enzymes was dominant in intra-vascular and intra-alveolar (IVA) simultaneously (53.84 %). Serum CRP in MPO enzyme IV and MPO enzyme IVA showed no significant difference (p = 0.774), while serum neutrophil in MPO enzyme IV and MPO enzyme IVA showed a significant difference (p = 0.025). There was no significant correlation between serum CRP and lung tissue MPO enzyme (p = 0.331), and also serum neutrophils and lung tissue MPO enzyme (p = 0.073).

CONCLUSION

The increasing of serum CRP and neutrophils were not correlated with lung tissue MPO enzyme. Serum neutrophil in MPO enzyme IV and MPO enzyme IVA in patients with critical COVID-19 pneumonia was significant different. Serum CRP and neutrophil levels do not directly reflect the local lung inflammation based on MPO enzyme expression. The distribution of MPO in COVID-19 lung tissue indicates intense NETs activity, particularly in vascular and alveolar compartments.