ABSTRACT
The coronavirus disease 2019 (COVID-19) pandemic is the most severe worldwide crisis;it affects both human lives and the global economy;according to WHO, there are 156,496,592 confirmed cases, including 3,264,143 deaths up to 6 May 2021. The causative agent of COVID-19 is Coronavirus;lymphocyte count has been a marker of interest since the first COVID-19 publication. Lymphopenia is related to the disease severity;many immunological markers such as IL2Rá, CD107a and FasL can affect lymphopenia. To evaluate immunological markers (IL2Rá, CD107a and FasL) in mild and severe COVID-19 patients and correlation with disease severity and lymphopenia. Eighty-eight proofed COVID-19 patients were enrolled in this study, divided into two groups: mild and severe according to patients signs and symptoms, their lymphocytes count and immunological markers (IL2Rá, CD107a and FasL) were measured and statistically correlated. In mild patients group: the median age 57.7 years ± 12.7 (18-75 years), 25 males and 19 females, male to female ratio were 1:1, their WBC was 6.44 ± 2.2, ranging from 3.4 to 12.4, the lymphocytes were 2.8 ± 0.71 ranging from 1.6-4.2. In sever group patients: the median age 43 years ± 14.4 (26-80 years), 22 males and 22 females, male to female ratio was 1.3:1 their WBC was 12.1 ± 4.6, ranging from 4.1 to 26.6, Lymphocytes were 1.29 ± 0.69 ranging from 0.3-3.4. There was a significant difference between mild and severe cases for age, WBC and lymphocytes (P<0.05). Gender distribution was not significantly related to disease activity (P>0.05). Lymphopenia was not found in mild cases but 59.1% of severe cases had lymphopenia (P<0.05). There was a significant difference between mild and severe cases for IL2-Ra and CD107 (P<0.005). No significant relation between FasL and disease severity in our specimen. In conclusion, measuring serum levels of IL-2R, CD107a and FasL in COVID-19 patients will serve as a sensitive marker for monitoring patients conditions and provide a suitable tool to verify which patient will develop severe lymphopenia and may need care in the intensive care unit.