Hypocomplementemic urticarial vasculitis case with hemophagocytic lymphohistiocytosis following SARS-CoV-2 mRNA vaccination.

A 61-year-old man with no previous record of autoimmune disease developed fever, polyarthralgia, purpura, and urticaria-like rash 2 weeks after the first dose of the Moderna mRNA-1273 vaccine, and symptoms deteriorated following the second dose. He presented reduced erythrocyte and platelet counts, hyperferritinemia, high sIL-2R levels, and severe hypocomplementemia. We diagnosed hypocomplementemic urticarial vasculitis (HUVS), and his symptoms as well as laboratory findings improved following treatment with mPSL 1000 mg/day for 3 days and PSL 40 mg/day. Twelve weeks following treatment initiation, the patient relapsed with fever, sore throat, pancytopenia, and hyperferritinemia when the PSL dose was reduced to 12.5 mg/day. Bone marrow biopsy and MRI presented fatty marrow and hemophagocytosis. The patient's blood cells started recovering using ATG + CsA + EPAG therapy for hemophagocytic lymphohistiocytosis (HLH). This is the first case report of HUVS and HLH following SARS-CoV-2 mRNA vaccination. It is presumed that SARS-CoV-2 mRNA vaccine can induce the excessive production of certain types of cytokines, such as TNF-α, IL-1, IL-4, IL-5, IL-6, and IL-17 as a consequence of IL-6 Amplification (IL-6 Amp). SARS-CoV-2 mRNA-vaccines can cause disruption of immune homeostasis in healthy individuals. An extremely rare disease of HUVS complicated by HLH can be developed as a consequence.

COVID-19-associated-mucormycosis: possible role of free iron uptake and immunosuppression.

COVID-19-associated-mucormycosis, commonly referred to as the "Black Fungus," is a rare secondary fungal infection in COVID-19 patients prompted by a group of mucor molds. Association of this rare fungal infection with SARS-CoV-2 infection has been declared as an endemic in India, with minor cases in several other countries around the globe. Although the fungal infection is not contagious like the viral infection, the causative fungal agent is omnipresent. Infection displays an overall mortality rate of around 50%, with many other secondary side effects posing a potential threat in exacerbating COVID-19 mortality rates. In this review, we have accessed the role of free iron availability in COVID-19 patients that might correlate to the pathogenesis of the causative fungal agent. Besides, we have analyzed the negative consequences of using immunosuppressive drugs in encouraging this opportunistic fungal infection.

Secretion of von Willebrand Factor and Suppression of ADAMTS-13 Activity by Markedly High Concentration of Ferritin.

Hyperferritinemia is associated with poor outcomes in critically ill patients with sepsis, hemophagocytic lymphohistiocytosis (HLH), macrophage activation syndromes (MAS) and coronavirus disease 19 (COVID-19). Autopsies of hyperferritinemic patients that succumbed to either sepsis, HLH, MAS or COVID-19 have revealed disseminated microvascular thromboses with von Willebrand factor (VWF)-, platelets-, and/or fibrin-rich microthrombi. It is unknown whether high plasma ferritin concentration actively promotes microvascular thrombosis, or merely serves as a prognostic biomarker in these patients. Here, we show that secretion of VWF from human umbilical vein endothelial cells (HUVEC) is significantly enhanced by 100,000 ng/ml of recombinant ferritin heavy chain protein (FHC). Ferritin fraction that was isolated by size exclusion chromatography from the plasma of critically ill HLH patients promoted VWF secretion from HUVEC, compared to similar fraction from non-critically ill control plasma. Furthermore, recombinant FHC moderately suppressed the activity of VWF cleaving metalloprotease ADAMTS-13. These observations suggest that a state of marked hyperferritinemia could promote thrombosis and organ injury by inducing endothelial VWF secretion and reducing the ADAMTS-13 activity.