Defining immune correlates of disease severity is important to better understand the immunopathogenesis in COVID-19. Here we made use of a protein microarray platform to detect IgG- and IgA-reactive antibodies in sera and saliva respectively, and assess cross-reactivity between SARS-CoV-2 and endemic coronaviruses (eCoVs). IgG responses against the full protein of spike, but not the S1 subunit, were significantly higher in convalescent sera of patients with severe disease compared to mild disease and healthy controls. In addition, we detected reactivity of secretory IgA to eCoVs in saliva of patients with severe disease, not present in patients with moderate disease or seropositive healthy controls. These heterologous immune responses are in line with non-protective cross-reactivity, and support a potential role for immune imprinting in the pathogenesis of severe COVID-19.

A 64-year-old man suffering from an acute posterior wall myocardial infarction underwent primary percutaneous coronary intervention. After several aspiration attempts, tirofiban infusion and pre- and post-dilatation, a bare-metal stent was successfully implanted in the culprit right coronary artery. While the patient did not show any neurological symptoms before or during the procedure, he exhibited hemiplegia and loss of spontaneous speech. Additional magnetic resonance imaging showed an extensive brain stem infarction. This is the first report of a brain stem infarction as a complication of percutaneous coronary intervention.Electronic supplementary materialThe online version of this article (doi:10.1007/s12471-015-0717-2) contains supplementary material, which is available to authorized users.

SARS-CoV-2 infection elicits a cross-reactive and back boosting immune response from prior exposure to any of the human seasonal coronaviruses (HCoVs), but is has yet to be determined whether this response is associated with fatal outcome of severe COVID-19 disease. In a cohort of 58 hospitalized patients, we have shown that heterologous immune responses are associated with increased disease severity. Here, we report that a lower anti-spike IgG ratio of SARS-CoV-2 to HCoVs, in particular to the human coronavirus 229E, correlates with decreased neutralizing antibody titers, and is associated with a fatal disease course. These results support the hypothesis that pre-existing humoral immunity to spike antigens of HCoVs may impair an efficient immune response during COVID-19.