The aim of this study is to examine the relationship between the severity of fibrosis in the lung tissue and EGFR positivity in patients who died due to covid-19 pneumonia, with the demographic characteristics, comorbidities, biochemistry values, treatments they received, and radiological appearances. Transthoracic tru-cut biopsy will be performed on patients who have died in the intensive care unit with the diagnosis of Covid 19 pneumonia. EGFR positivity will be evaluated in the material taken. The relationship between the severity of fibrosis and the demographic data of the patients, the drugs used and their radiological appearances will be analyzed statistically.

The pathophysiology of Covid 19 infection still remains complex. Diffuse alveolo-interstitial damage, organizing pneumonia and severe fibrotic organizing pneumonia have been reported and possibly associated with cytokine storm. However, profibrotic pathways and mediators involved in fibrosis and the severity of fibrosis may differ individually. Epidermal growth factor (EGF) is a protein-structured growth factor that stimulates cell division, differentiation, survival, proliferation, growth and cell migration. It acts through the epidermal growth factor receptor (EGFR). The stimulating effect of fibroblasts, kerotinocytes, and vascular endothelial cells is known to stimulate growth and proliferation, and plays a role in the repair process of the lungs and the development of pulmonary fibrosis. EGFR is also a tyrosine kinase receptor. The relationship between fibrosis severity and EGFR positivity in the tissues of deceased covid pneumonia patients, demographic data of the patients, their combinations and the treatment they receive may guide treatment approaches.

The aim of this study is to examine the relationship between the severity of fibrosis in the lung tissue and EGFR positivity in patients who died due to covid-19 pneumonia, demographic characteristics, comorbidities, biochemistry values, and treatments they receive.

Material methods: Transthoracic tru-cut biopsy will be performed with the permission of their families, for patients hospitalized in the intensive care unit of our hospital and who died due to Covid 19 pneumonia. Biopsy, where the involvement is more intense compared hemithorax to the radiological appearance, will be performed blindly. By studying EGFR on biopsy materials, fibrosis grade will be classified as 0=none; 1=mild; 2=medium; 3=severe. Thoracic CT images of the patients were reviewed by a radiologist, and the fibrosis image and extent will again be classified as 0=none; 1=mild; 2=medium; 3=severe. Medications used, additional diseases, demographic data, length of stay in the intensive care unit, and intubation times will be recorded. The relationship between EGFR positivity and other data will be analyzed statistically.

The relationship between fibrosis severity and EGFR positivity in the tissues of deceased covid pneumonia patients, demographic data of the patients, their combinations and the treatment they receive may guide treatment approaches. It may shed light on the fact that fibrolytic drugs, which act as tyrosine kinase inhibitors and are used in idiopathic interstitial fibrosis, can also be used in covid 19 pneumonia damage.

Inclusion Criteria:

• > 18 years old
• Patients who died while lying in the Intensive Care Unit with the diagnosis of Covid-19 pneumonia

Exclusion Criteria:

• <18 years old
• Patients who were treated with the diagnosis of Covid 19 pneumonia and recovered