Fucosylation of antibodies in multi-inflammatory syndrome in children after SARS-CoV-2 infection

The COVID-19 pandemic caused by SARS-CoV-2, has 24 million confirmed cases and
more than 800.000 deaths. Patient responses to SARS-CoV-2 (COVID-19) are highly
diverse, ranging from asymptomatic or mild self-limiting infection, to a severe
upper airway inflammation leading to respiratory distress, often with a fatal
outcome. This suggests different paths taken by the immune system to combat
the disease, so far there is no clear evidence that can make a distinction
between these two different immunological and pathological paths. It is also
not known how the immune response to COVID in MIS-C compares to other
hyperinflammatory diseases in childhood such as juvenile idiopathic arthritis.

In the recent past, have discovered that antibody responses to enveloped viral
infections can be altered. Posttranslational modification through glycosylation
can either give a protective response or enhance the disease phenotype through
an overreacting immune response. There have been many cases of children and
adolescents with COVID-19-assocated multisystem inflammatory conditions, which
seems to develop after a COVID-19 infection. The multisystem inflammatory
syndrome in children (MIS-C) can lead to shock and multiple organ failure
requiring intensive care. The pathophysiology of MIS-C is still unclear.

To study the antibody response as a disease modifying factor in the context of
COVID-19, we will compare the anti-CoV antibody composition, quality and
interaction with immune receptors.

This is a non-interventional, observational case-control study:
Cases: laboratory-confirmed SARS-CoV-2 infection with MIS-C. We will recruit
retrospective and prospective cases. A single blood draw is taken from
retrospective cases and two blood draws from prospective cases. For the main
analysis all cases will be pooled. Furthermore they will get a short
questionary.

Controls: three control populations will be distinguished in (A) children
suspected of MIS-C but with negative COVID diagnostics, (B) children with
proven acute COVID respiratory infection and (C) otherwise healthy children
prior to elective surgery. A single blood draw prior to surgery is taken from
control group 3 and two blood draws from control group 1 and control group 2.
Furthermore they will get a short questionary.

There will be a blood draw, which is the most stressful part.