Laboratory manifestations and pathophysiological aspects of coronavirus disease 2019 pandemic: focusing on the digestive system.

Since December 2019, the severe acute respiratory syndrome coronavirus 2 has constituted a serious threat to global health. So far, there is little published evidence on the laboratory features of coronavirus disease 2019 (COVID-19). We have reviewed laboratory findings from multiple studies, mostly relating to the digestive system, since the virus outbreak. Laboratory data from older coronaviruses endemics, as well as other RNA viruses, were also reported. Although the main route of transmission is considered to be respiratory droplets, the distribution of ACE2 receptors in the gastrointestinal tract in combination with the detection of the virus in feces may imply a potential fecal-oral transmission route, and thus, emphasis should be given to patients with gastrointestinal symptoms. Interestingly, there is evidence that severe acute respiratory syndrome coronavirus 2 displays similar laboratory and clinical findings with older members of the coronavirus family, and so, comparable diagnostic and therapeutic approaches may be used. Regarding laboratory abnormalities, lymphopenia appears to be the most common finding, together with coagulation disorders and inflammatory markers elevation, reflecting a sustained systemic response. Abnormal liver and, occasionally, pancreatic tests are also common and even more severe in patients with gastrointestinal symptoms or diseases. Thus, the aim of this study is to focus on the laboratory and pathophysiologic side of this novel disease in order to strengthen current knowledge and urge further research. Detailed investigation of numerous studies may suggest a common laboratory pattern between COVID-19 patients. It is important for clinicians not to underestimate patients with gastrointestinal comorbidities, as they have been associated with severe COVID-19 disease.

COVID-19 pandemic: Pathophysiology and manifestations from the gastrointestinal tract.

The pandemic of coronavirus disease 2019 (COVID-19), caused by a newly identified ß-coronavirus (SARS-CoV-2) has emerged as a dire health problem, causing a massive crisis for global health. Primary method of transmission was firstly thought to be animal to human transmission. However, it has been observed that the virus is transmitted from human to human via respiratory droplets. Interestingly, SARS-CoV-2 ribonucleic acid (RNA) has been isolated from patient stools, suggesting a possible gastrointestinal (GI) involvement. Most commonly reported clinical manifestations are fever, fatigue and dry cough. Interestingly, a small percentage of patients experience GI symptoms with the most common being anorexia, diarrhea, nausea and vomiting. The presence of viral RNA in stools is also common and fecal tests can be positive even after negative respiratory samples. The exact incidence of digestive symptoms is a matter of debate. The distribution of Angiotensin converting enzyme type 2 receptors in multiple organs in the body provides a possible explanation for the digestive symptoms' mechanism. Cases with solely GI symptoms have been reported in both adults and children. Viral RNA has also been detected in stool and blood samples, indicating the possibility of liver damage, which has been reported in COVID-19 patients. The presence of chronic liver disease appears to be a risk factor for severe complications and a poorer prognosis, however data from these cases is lacking. The aim of this review is firstly, to briefly update what is known about the origin and the transmission of SARS-CoV-2, but mainly to focus on the manifestations of the GI tract and their pathophysiological background, so that physicians on the one hand, not to underestimate or disregard digestive symptoms due to the small number of patients exhibiting exclusively this symptomatology and on the other, to have SARS-CoV-2 on their mind when the "gastroenteritis" type symptoms predominate.