MOG-IgG positive optic neuritis after SARS-CoV-2 infection.

BACKGROUND: Many neurologic complications have been described after severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) including atypical cases of optic neuritis (ON), positive to myelin oligodendrocyte glycoprotein (MOG) IgG. OBJECTIVE: To report a case of MOG-IgG-associated ON and discuss why SARS-CoV-2 infection could be a potential trigger. METHODS: Retrospective single case report. RESULTS: We report a case of ON with positive MOG-IgG developed 15 days after presentation of SARS-CoV-2 infection. CONCLUSION: This report suggests that SARS-CoV-2 infection may have triggered autoantibodies production against MOG leading to ON.

Immunogenicity and safety of mRNA COVID-19 vaccines in people with multiple sclerosis treated with different disease-modifying therapies.

The potential impact of disease-modifying therapies (DMTs) for multiple sclerosis (MS) on COVID-19 vaccination is poorly understood. According to recent observations, the humoral immune response could be impaired in patients treated with ocrelizumab or fingolimod. Our study evaluated the immunogenicity and safety of mRNA COVID-19 vaccines in a convenience sample of 140 MS patients treated with different DMTs, undergoing vaccination between April and June 2021. Humoral immune response was tested 1 month after the second dose, using a chemiluminescent microparticle immunoassay to detect IgG against SARS-CoV-2 nucleoprotein. We explored the potential correlation between the IgG titer and DMTs. All patients in treatment with first-line DMTs, natalizumab, cladribine, and alemtuzumab, developed a measurable humoral response. In patients treated with ocrelizumab and fingolimod, the IgG level was significantly lower, but only some patients (22.2% for fingolimod and 66% for ocrelizumab) failed to develop a measurable humoral response. In the ocrelizumab group, the IgG level was positively correlated with the time from last infusion. No SARS-CoV-2 infections were reported after vaccination. The most reported side effects were pain at the injection site (57.1%) and fatigue (37.9%). No patient experienced severe side effects requiring hospitalization. Our study confirms that COVID-19 vaccination is safe and well-tolerated in MS patients and should be recommended to all patients regardless of their current DMTs. Since fingolimod and ocrelizumab could reduce the humoral immune response, in patients treated with these drugs, detecting SARS-CoV-2 antibodies could be helpful to monitor the immune response after vaccination.

HIF-1, the Warburg Effect, and Macrophage/Microglia Polarization Potential Role in COVID-19 Pathogenesis.

Despite the international scientific community's commitment to improve clinical knowledge about coronavirus disease 2019 (COVID-19), knowledge regarding molecular details remains limited. In this review, we discuss hypoxia's potential role in the pathogenesis of the maladaptive immune reaction against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). The state of infection, with serious respiratory dysfunction, causes tissues to become hypoxic due to a discrepancy between cellular O2 uptake and consumption similar to that seen within tumor tissue during the progression of numerous solid cancers. In this context, the heterogeneous clinical behavior and the multiorgan deterioration of COVID-19 are discussed as a function of the upregulated expression of the hypoxia-inducible factor-1 (HIF-1) and of the metabolic reprogramming associated with HIF-1 and with a proinflammatory innate immune response activation, independent of the increase in the viral load of SARS-CoV-2. Possible pharmacological strategies targeting O2 aimed to improve prognosis are suggested.