Alterations in microcirculatory oxygenation in long-COVID

Recruitment & Eligibility

Status: Pending

Sex: Not specified

Target Recruitment: 106

Inclusion Criteria

Long-COVID patients
• Age >= 18 years, <65 years
• Past COVID-19 diagnosis, based on
o Positive PCR
o Positive Sars-Cov2 serology
o Positive rapid antigen test
o Typical clinical syndrome during the first pandemic wave, when testing was
not possible
• Long-COVID-19 diagnosis based on World Health Organisation consensus
diagnosis: (*Post COVID-19 condition occurs in individuals with a history of
probable or confirmed SARS CoV-2 infection, usually 3 months from the onset of
COVID-19 with symptoms and that last for at least 2 months and cannot be
explained by an alternative diagnosis. Symptoms may be new onset following
initial recovery from an acute COVID-19 episode or persist from the initial
illness. Symptoms may also fluctuate or relapse over time)*
• Overall functioning <70% compared to functioning prior to onset of
Long-COVID/ COVID-19 infection
• Long COVID duration > 6 months
• Presence of post-exertional malaise
• Provided written informed consent

Convalescent Controls
• Age >= 18 years, <65 years
• Past COVID-19 diagnosis, based on
o Positive PCR
o Positive Sars-Cov2 serology
o Positive rapid antigen test
o Typical clinical syndrome during the first pandemic wave, when testing was
not possible
• No diagnosis of long-COVID, good recovery. Overall functioning >95% compared
to functioning prior COVID-19 infection
• Self-reported general good wellbeing
• Provided written informed consent

Exclusion Criteria

Long-COVID patients
• Unable or not willing to provide written informed consent
• Unable to complete written questionnaires in Dutch
• Unable to draw blood for study purposes
• Diagnosis of dementia
• Active treatment with hyperbaric oxygen treatment during study start
• Alternative diagnosis that may explain clinical symptoms
• Suffering from any pre-existing immune-driven disease or use of
anti-inflammatory therapy of any kind (including NSAIDs and steroids) during
the last 3 months
• Suffering from diabetes mellitus, hypertension, severe mental conditions or
use of anticoagulant treatment in the past 4 weeks.
• No re-infection with COVID-19 in the past 3 months

Convalescent Controls
• Unable or not willing to provide written informed consent
• Unable to complete written questionnaires in Dutch
• Unable to draw blood for study purposes
• Diagnosis of dementia
• Genetically related to participating patients (e.g. brother/sister/parent)
• Suffering from any immune-driven disease or use of anti-inflammatory therapy
of any kind (including NSAIDs and steroids), including during the last 3 months
• Suffering from diabetes mellitus, hypertension, severe mental conditions or
use of anticoagulant treatment in the past 4 weeks.
• Re-infection with SARS-CoV-2 in the past 3 months.

Study & Design

Study Type: Observational invasive

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>I: Difference between groups (long-COVID versus control) in the change in<br /><br>microcirculatory Hb saturation (%) as determined by handheld sublingual<br /><br>reflective spectrophotometry before and after physical exercise (1 min sit to<br /><br>stand test).<br /><br>II: Difference between groups (long-COVID versus control) in plasma levels of<br /><br>VEGF-A. </p><br>

Secondary Outcome Measures