الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 161 |  |  |
| | | from | 161 | | |
Abstract
The COVID-19 epidemic represents a substantial challenge for governments, individuals, and society, COVID-19 began through a novel coronavirus (CoV-2) that causes SARS. The clinical presentation of COVID-19 varies with the severity of the disease either mild, moderate, severe, or critical. COVID-19 has resulted in high rates of morbidity and mortality worldwide. Interleukin (IL-22) is a vital signaling molecule produced by T cells in response to lung injury. It plays a significant role in innate immune responses and tissue regeneration. Due to its involvement in regeneration, host defense, and pathological conditions, IL-22 is a crucial target for clinical development. L-tryptophan (L-TRP) is a large neutral amino acid in living organisms, incorporated in proteins during mRNA translation. Indoleamine 2, 3-dioxygenase (IDO) catalyzes the initial step in TRP catabolism via the kynurenine degradation pathway. IDO is thought to play a crucial role in a variety of pathophysiological processes including antimicrobial and antitumor defense, neuropathology, immune regulation, antioxidant activity, and suppression of autoimmunity. Therefore, the present study aimed to evaluate the levels of cytokines particularly IL-22 and some tryptophan metabolites, particularly IDO in COVID-19 patients to highlight a possible role IL-22 and IDO in the prognosis and severity of COVID-19. The results of this investigation will advance our knowledge of the intricate immune control that occurs during COVID-19 infection and could point to important therapeutic targets for averting the serious consequences of such disease. This study including (46) clients was conducted between April 2020 and September 2020 on patients suffering from signs and symptoms of COVID-19 based on the classification of Ministry of Health guidelines in Tanta University Quarantine Hospital. Cases were selected to be older than 18 years and meet the COVID-19 virological case definition [positive detection of viral genome in nasopharyngeal swabs by reverse transcription - polymerase chain reaction (RT-PCR). Based on COVID-19 severity, patients were divided into 4 main groups mild- to moderate, severe, and critical illness clinical stage definition for COVID-19 as follows: The first group includes 5 cases with a mild infection, the second group includes 8 cases with a moderate infection, the third group includes 10 cases with a severe infection, the fourth group includes 4 critically ill cases, and the fifth group includes 14 vaccinated volunteers. the last group included 5 healthy control volunteers who were also enrolled. All patients were subjected to the following: 1- Detailed history taking 2- Detailed clinical examinations and biochemical analysis. 3- Written informed consent. 4- Confirmed diagnosis of COVID-19 by PCR or antigen test. 5- Routine laboratory investigations. The current study revealed the following results: • Age has a significant effect on the COVID-19 incidence and severity in both male and female patients; as the patients become older, the incidence and severity of the disease increase toward the elderly. on the other hand, both Gender and smoking influence disease incidence and severity but in an insignificant way. • The O2 saturation decreases with the disease severity, which is significant compared to the control group where the normal range of O2 saturation lies between (95%-100%) but in chronic obstructive pulmonary diseases and lung diseases it becomes lower as seen in both critical and severe groups. Target SpO2 of (92% - 96%) seems logical, considering that indirect evidence from patients without COVID-19 suggests that a SpO2 of a value < 92% or > 96% may be harmful. • These results showed that D-dimer did not significantly increase in both mild and moderate but increased significantly in both severe and critically ill patients. This suggests that D-dimer has a serious effect on the COVID-19 severity in both severe and critical patients. It means that persons with D dimer probably suffer from a clotting disorder or not, but they can’t show where the clot is located or what type of clotting disorder they have. However, high D -dimer levels may be due to smoking, heart diseases, severe lung diseases, or the age of patients being > 60 years old. • It is noticed that IDO increased in moderate (50) pg./ml. and severe (95) pg./ml. COVID-19 groups and on the contrary, mild, and critical patients (44) pg./ml. had no significant difference compared to the control. Vaccinated patients retained IDO concentration once again near the normal value (40) pg./ml. The reference concentration range of IDO ranges from (40 - 60) pg./ml. in addition, IDO, a tryptophan metabolite, acts as an innate immune factor that is increased in infectious lung diseases (COVID-19). • IL-22 showed upregulated levels in the plasma of patients with moderate (55) pg./ml, with severe (120) pg./ml and in critical cases (55) pg./ml in a significant manner. It was unchanged compared to the control clients (40) pg/ml in the other groups where its level fluctuated up and down but without significant difference even in vaccinated cases (40) pg./ml. The normal concentration of IL-22 ranges from (40-60) pg./ml. Read out, IL-22 is an excellent predictor of COVID-19 and more likely to develop COVID-19. • The platelets count insignificantly fluctuated in COVID-19 groups compared to the control. It was noticeable that [Hb] and platelets count were not affected significantly by COVID-19 even in vaccinated patients and it seems that they do not have an important role in COVID-19 development. • A decrease in WBCs count was produced in mild and moderate groups indicating a disturbance in the immune elements at the beginning of COVID- 19. In severe and critical groups, WBCs begin to rise pointing to the immune stimulation mechanisms to increase WBCs in the peripheral blood and the immune elements become more sensible. • The results revealed that lymphopenia is a prominent marker for COVID-19 severity, and vaccination is a required implement to enhance the immune function in COVID-19 patients. • The inflammatory protein (CRP) was increased significantly in severe and critical groups but had a less significant effect in mild and moderate groups, indicating a crucial role of CRP in the COVID-19 development. • It also resulted that the degree of fever in COVID-19 patients rises as the degree of severity of disease increases as a result of immune reaction with the virus. In the same context, the severe and critical cases had the highest body temperature, and they were in emergency. • As the severity of COVID-19 increases, the absence percentage of comorbidities decreases toward severity of COVID-19. Consequently, the percentages of cure in both mild and moderate patients’ groups reached 100%, Unfortunately, no cure and lung fibrosis in severe and critical groups and all patients were dead with a percentage reaching 100%. • An invasive ventilation (IV) mechanism can used in patients with severe symptoms who need critical care unit. Also, non-invasive ventilation (NIV) could be useful as a respiratory support in the early stages of infection to prevent silent hypoxia as a complication of COVID-19. • Oxygen reservoir can be used as a tool for the early diagnosis of mild COVID-19. Patients who are asymptomatic or mildly symptomatic can be readily implemented to ameliorate the health system burden by using an O2 reservoir without sacrificing safety or effectiveness. Conclusion: It can be concluded that infection of people with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) leads to coronavirus disease 2019 (COVID- 19). COVID-19 infection exaggerated with other factors and diseases such as age, smoking, hypertension, and diabetes. Older individuals and those with type 2 Diabetes mellitus and high blood pressure are more susceptible to such viral infection. This disease causes the activation of immune-inflammatory pathways and oxidative stress, both of which induce an increment of IL-22 and IDO production. Our findings suggest that IDO enzyme activity is increased in COVID-19 patients. Also, the obtained results concerning IDO is implicated in pathophysiology, complications, and progression of COVID-19. Offering the health care services especially intensive ventilation and oxygen supply can reduce COVID-19 comorbidities and enhance the health and survival.