PATIENTS AND METHODS: A retrospective study included 521 Egyptian patients diagnosed with COVID-19. Data was retrieved from the medical records of patients who were admitted from April 2020 to October 2021 in Kasr Al-Ainy Hospitals, Cairo University, with categorization according to disease severity in correspondence to the four waves.

RESULTS: The median age was lower in the first wave compared to other waves, with male predominance across all waves. The most commonly encountered comorbidity overall was hypertension, followed by diabetes mellitus. White blood cells, ferritin, and interleukin-6 showed the highest median values in the second wave, with significantly higher median C-reactive protein on day 1 in the first wave. Forty percent of the patients showed elevated hepatic transaminases on admission in four waves, with no statistically significant difference between waves. On day 5, around half of the patients had elevated transaminases, with no significant difference between waves. Most CT findings were of moderate severity. Clinical severity was higher in the second wave. It was observed that the higher the disease severity, the greater the proportion of patients with elevated hepatic transaminases. The mortality rate was markedly high in cases who had elevated ALT or AST on day 5. The association between elevated enzymes on admission and mortality was seen in the first wave only, with a fatality rate of 22.5% in cases with increased baseline ALT and AST versus 5% in those with normal baseline enzymes.