ABSTRACT
COVID-19 pandemic caused by SARS-CoV-2 virus has been around for 2 years causing significant health-care catastrophes in most parts of the world. The understanding of COVID-19 continues to expand, with multiple newer developments such as the presence of asymptomatic cases, feco-oral transmission, and endothelial dysfunction. The existing classification was developed before this current understanding. With the availability of recent literature evidences, we have attempted a classification encompassing pathogenesis and clinical features for better understanding of the disease process. The pathogenesis of COVID-19 continues to evolve. The spiked protein of the SARS-CoV-2 virus binds to ACE2 receptors causes direct cytopathic damage and hyperinflammatory injury. In addition to alveolar cells, ACE2 is also distributed in gastrointestinal tract and vascular endothelium. ACE2–SARS-CoV-2 interaction engulfs the receptors leading to depletion. Accumulation of Ang2 via AT1 receptor (AT1R) binding causes upregulation of macrophage activity leading to pro-inflammatory cytokine release. Interleukin-6 (IL-6) has been attributed to cause hyperinflammatory syndrome in COVID-19. In addition, it also causes severe widespread endothelial injury through soluble IL-6 receptors. Thrombotic complications occur following the cleavage and activation of von Willebrand factor. Based on the above understanding, clinical features, organ involvement, risk stratification, and disease severity, we have classified COVID-19 patients into asymptomatic, pulmonary, GI, and systemic COVID-19 (S-COVID-19). Studies show that the infectivity and prognosis are different and distinct amongst these groups. Systemic-COVID-19 patients are more likely to be critically ill with multi-organ dysfunction and thrombo-embolic complications.
ABSTRACT
Living related liver transplantation (LRLT) was made possible because of a better understanding of the anatomy of the liver and advances made in hepatic surgical techniques. It was developed to reduce the waiting period for pediatric recipients. In countries like Japan, which do not have brain stem death legislation, LRLT is the only modality available for treating end stage liver disease. The world experience has shown that LRLT has been successfully performed in a variety of conditions leading to acute and chronic liver failure not only in children, but in young adults as well. The initial results of LRLT appear to be better than liver transplantation from cadaveric organs in terms of graft survival and function. Donor safety has been of prime concern. LRLT has tremendous potential in India with or without the brain stem death legislation. Liver transplantation has not been performed in India although the need and expertise for it exists.