Immune Targeted Therapies for COVID-19 Infection: A Narrative Review

In December 2019, the coronavirus disease-2019 (COVID-19) outbreak emerged in Wuhan, China. The World Health Organization officially declared it a pandemic on March 11, 2020. Reports indicated that the associated mortality of the infection is quite higher in the elderly, individuals with specific comorbidities (such as diabetes mellitus), and generally the ones with a compromised immune system. A cohort study in Wuhan, China, reported a dysregulated immune response in 452 patients with laboratory-confirmed COVID-19. As a result of this suppressed immune response, an increase in neutrophil to lymphocyte ratio, T lymphopenia, and a decrease in CD4⁺ T cells were all common laboratory findings, especially in severe cases. On the other hand, there is substantial evidence of T cell exhaustion in critically ill patients. Accordingly, the immune system seems to play an important role in the prognosis and pathogenesis of the disease. Therefore, this study aims to review the evidence on the immune response dysregulation in COVID-19 infection and the potential role of immunoregulatory treatments such as immune checkpoint inhibitors, interferons, and CD200 inhibitors in altering disease prognosis, especially in critically ill patients.

Isotretinoin and the Kidney: Opportunities and Threats

Retinoids are one of the most effective drugs in inducing complete or prolonged remission of severe acne vulgaris, but the adverse reactions associated with the use of them are raising a concern about the potential effect of these drugs on internal organs function such as the kidney. The aim of this review is to comprehensively gather data about isotretinoin, both potential adverse and beneficial effects on the kidney based on the current experimental and clinical findings. Very few studies, including five case reports, described that systemic oral isotretinoin within usual doses (40 mg/day or 0.5 mg/kg⁄day) within 1 to 4 months of treatment might be associated with different types of renal dysfunctions. These include acute interstitial nephritis, nephrotic syndrome, and hematuria with dysuria. The adverse reactions of systemic isotretinoin on the kidney and urinary system are unlikely and rare. In contrast, six experimental studies demonstrated the beneficial effects of either oral or parenteral low- (2 or 5 mg/kg/day) or high- (10, 20, 25, 40 mg/kg/day) dose isotretinoin on the kidney in the rat models of glomerulonephritis, obstructive nephropathy or allograft nephropathy. The nephroprotective functions of isotretinoin in these studies were attributed to its anti-proliferative, anti-fibrotic, and anti-inflammatory actions. However, clinical studies are warranted to elucidate the possible beneficial effects of isotretinoin in preventing or attenuating kidney injury in different settings.