Correlation of ferritin with the duration of illness, disease severity, oxygenation status, ventilatory requirement, and lung fibrosis in COVID-19 pneumonia: A single-center experience of 1000 cases in tertiary care setting in India

Abstract

Objective: Robust data of ferritin are available as prognostic marker in bacterial infection and we have analyzed its usefulness in COVID-19 pneumonia in predicting severity of illness, response to treatment, and final outcome. Materials and Methods: A prospective and observational study 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) thorax, oxygen saturation, inflammatory marker, ferritin at entry point, and follow-up during hospitalization. Age, gender, comorbidity, and use Bi-level positive airway pressure (BIPAP)/Non invasive ventilation (NIV) and outcome as with or without lung fibrosis as per CT severity were key observations. Statistical analysis is done using Chi-square test. Results: In a study of 1000 COVID-19 pneumonia cases, age (<50 and >50 years) and gender (male vs. female) have significant association with ferritin (P < 0.00001) and (P < 0.010), respectively. CT severity score at entry point with ferritin level has significant correlation in severity score (P < 0.00001). Ferritin level has significant association with the duration of illness (P < 0.00001). Comorbidities have significant association with ferritin level (P < 0.00001). Ferritin level has significant association with oxygen saturation (P < 0.00001). BIPAP/NIV during hospitalization has significant association with ferritin level (P < 0.00001). Timing of BIPAP/NIV requirement in critical care setting has significant association with ferritin level (P < 0.00001). Follow-up ferritin titer during hospitalization as compared to entry point normal and abnormal ferritin has significant association in post-COVID lung fibrosis, respectively (P < 0.00001). Conclusion: Ferritin is easily available, and universally acceptable inflammatory marker in COVID-19 pandemic, documented very crucial role in predicting severity of illness and assessing response to treatment and follow-up ferritin titer during hospitalization, can be used as early predictor of post-COVID lung fibrosis.