Role of C-Reactive protein in COVID-19 pneumonia as “A jack of all trades is a master of none!”: A single-center experience of 2000 cases

Introduction: Robust data of C-reactive protein (CRP) are available in bacterial infection, and it can be utilized in this coronavirus disease 2019 (COVID-19) pneumonia pandemic for initial assessment and planning of treatment in indoor setting in association with high-resolution computed tomography (HRCT) severity. Methods: A prospective, observational, 12-week follow-up study included 2000 COVID-19 cases confirmed with reverse transcription–polymerase chain reaction (RT-PCR). All cases were assessed with lung involvement documented and categorized on HRCT thorax, oxygen saturation, CRP at entry point, and follow-up. Protocolised recordings of age, gender, comorbidity, and bilevel-positive airway pressure (BIPAP)/non-invasive ventilation (NIV) use were done. Final radiological outcome as with or without lung fibrosis as per follow-up computed tomography in accordance to entry point severity were analysed. Clinical and final outcomes were recorded as per requirement of interventions in indoor units. Statistical analysis was done by Chi-square test. Results: HRCT severity score at entry point has a significant correlation with CRP titer (P < 0.00001). CRP titer has a significant association with duration of illness (P < 0.00001). Comorbidities have a significant association with CRP titer (P < 0.00001). CRP titer has a significant association with oxygen saturation (P < 0.00001). BIPAP/NIV requirement during hospitalization has a significant association with CRP titer (P < 0.00001). Timing of BIPAP/NIV requirement has a significant association with CRP titer (P < 0.00001). Follow-up CRP titer during hospitalization as compared to entry point (initial) normal and abnormal CRP has a significant association in post-COVID lung fibrosis (P < 0.00001). Conclusions: CRP has documented a very crucial role in COVID-19 pneumonia in predicting severity of illness at entry point and progression of illness during course of hospitalization. Role of CRP as “a jack of all trades is a master of none” in COVID-19 pneumonia is a real misnomer due to its major impact on guiding step-up and step-down interventions in critical care units. CRP is considered a 'game changer' inflammatory molecule during the entire course of COVID-19 assessment. Role of CRP as an inflammatory marker “oftentimes better than a master of one” in comparison to other available markers interleukin-6, ferritin, and lactate dehydrogenase due to easy availability and cost-effectiveness.