Role of ferritin as "Core Marker" in the assessment of severity, response to therapy and predicting outcome in COVID-19 pneumonia: A large, two-center, prospective, observational study of 1000 cases in tertiary care setting in India

ABSTRACT

Introduction: Coronavirus disease 2019 (COVID-19) pneumonia is heterogeneous disease with variable effect on lung parenchyma, airways, and vasculature, leading to long-term effects on lung functions. Robust data of ferritin in bacterial infection are available, and now its role as an inflammatory marker in COVID-19 pneumonia during initial assessment and planning of treatment is evolving. Materials and Methods: Prospective, two-center, observational study conducted from July 2020 to May 2021, in MIMSR Medical College and Venkatesh Hospital Latur, India, included 1000 COVID-19 cases confirmed with reverse transcription-polymerase chain reaction. All cases were assessed with lung involvement documented and categorized on high-resolution computed tomography (CT) of the thorax, oxygen saturation, inflammatory marker, Ferritin at the entry point, and follow-up during hospitalization. Age, gender, comorbidity, and use BIPAP (bi-level positive airway pressure)/NIV (noninvasive ventilation) (BIPAP/NIV) and outcome with or without lung fibrosis as per CT severity were key observations. CT severity scoring was done as per universally accepted standard scoring tool as score < 7 as mild, 7-14 as moderate, and score > 15 as severe affection of lung. Statistical analysis is performed using Chi-square test. Results: Age (50 years) and gender (male versus female) have significant association with ferritin in predicting severity of COVID 19 pneumonia (P < 0.00001) and (P < 0.010), respectively. CT severity score at the entry point with ferritin level has a significant association (P < 0.00001). Ferritin level has a significant association with the duration of illness (P < 0.00001). Comorbidities have a significant association with normal and abnormal ferritin levels, respectively (P < 0.00001). Ferritin level has a significant association with oxygen saturation (P < 0.00001). BIPAP/NIV requirement during treatment in critical care settings has a significant association with ferritin level (P < 0.00001). Timing of BIPAP/NIV requirement during the course of COVID-19 pneumonia in critical care settings has a significant association with ferritin level (P < 0.00001). Follow-up ferritin titer during hospitalization as compared to entry point normal and abnormal ferritin has a significant association in post-COVID lung fibrosis, respectively (P < 0.00001). Conclusions: Ferritin is easily available, sensitive, reliable, cost-effective, and universally acceptable inflammatory marker in COVID-19 pneumonia. Ferritin has a very crucial role in COVID-19 pneumonia in predicting the severity of illness and assessing response to treatment during hospitalization. Follow-up ferritin titer during hospitalization and at discharge can be used as early predictor of post-COVID lung fibrosis.