Remodeling of the Immune Response With Aging: Immunosenescence and Its Potential Impact on COVID-19 Immune Response.

Elderly individuals are the most susceptible to an aggressive form of coronavirus disease (COVID-19), caused by SARS-CoV-2. The remodeling of immune response that is observed among the elderly could explain, at least in part, the age gradient in lethality of COVID-19. In this review, we will discuss the phenomenon of immunosenescence, which entails changes that occur in both innate and adaptive immunity with aging. Furthermore, we will discuss inflamm-aging, a low-grade inflammatory state triggered by continuous antigenic stimulation, which may ultimately increase all-cause mortality. In general, the elderly are less capable of responding to neo-antigens, because of lower naïve T cell frequency. Furthermore, they have an expansion of memory T cells with a shrinkage of the T cell diversity repertoire. When infected by SARS-CoV-2, young people present with a milder disease as they frequently clear the virus through an efficient adaptive immune response. Indeed, antibody-secreting cells and follicular helper T cells are thought to be effectively activated in young patients that present a favorable prognosis. In contrast, the elderly are more prone to an uncontrolled activation of innate immune response that leads to cytokine release syndrome and tissue damage. The failure to trigger an effective adaptive immune response in combination with a higher pro-inflammatory tonus may explain why the elderly do not appropriately control viral replication and the potential clinical consequences triggered by a cytokine storm, endothelial injury, and disseminated organ injury. Enhancing the efficacy of the adaptive immune response may be an important issue both for infection resolution as well as for the appropriate generation of immunity upon vaccination, while inhibiting inflamm-aging will likely emerge as a potential complementary therapeutic approach in the management of patients with severe COVID-19.

Renal cortical necrosis complicating laundry detergent ingestion.

Accidental oral detergent ingestion usually causes mild gastrointestinal manifestations including nausea, vomiting and diarrhea as well as upper airway irritation. There are a limited number of reported oral detergent ingestions leading to acute kidney injury, mainly due to rhabdomyolysis. We present an ultimately fatal case of laundry detergent ingestion leading to biopsy proven severe cortical necrosis and irreversible renal damage. Detergent ingestion was associated with widespread endothelial injury leading to a picture of thrombotic microangiopathy. Among the detergent ingredients ingested by the patient, sodium borate raised the highest concern as a potential toxin exacerbated further by severe hypovolaemia and consequent decrease in renal toxin excretion. As sodium borate is dialyzable, haemodialysis should be a consideration early after laundry detergent ingestion.