SARS-CoV-2 and Co-morbidities

Abstract

In December 2019, cases of pneumonia emerged in Wuhan, China, which was indicated to be due to a novel coronavirus called SARS-CoV-2 or COVID-19. This virus shares a lot of similarities with the previous SARS-Cov and MERS-Cov, yet its spread has been recorded to be much faster, with more than 80 million cases and close to 1 million deaths in the USA by March 2022. Further, the CDC has released a list of health conditions that increase the risk of acquiring the virus and its severity by 12- folds. Those conditions include diabetes, cardiovascular diseases, chronic kidney disease, cancer, chronic obstructive pulmonary disease, sickle cell anemia, obesity, and immunocompromised states. The two common mechanisms increasing the susceptibility of patients with any of the aforementioned co-morbidities are 1) increased inflammation causing a “cytokine storm”; and 2) suppressed or delayed immune system response, which is expected to be highly responsive in infections. The “cytokine storm” is characterized by an increased release of cytokines that cause an impaired response of the macrophages and lymphocytes that are expected to be highly responsive under any state of infection. Further, these conditions are known to be states of chronic low-grade inflammation, which adds to the cytokine storm with the suppression of the immune response. This disruption equally influences the involvement of B-cells and T-cells in the resolution of infections. Finally, some conditions may suffer from disturbances at the levels of the respiratory system, such as difficulty breathing, accompanied by respiratory muscles inefficiency and inequality in ventilation perfusion, causing hypoxia and the increased need for mechanical ventilation and ICU admission. The objective of this chapter is to introduce the main chronic conditions mostly influenced by SARS-Cov-2, the severity of the virus, its prevalence among the recorded cases, and the consequence observed at the level of the immune system.