IntroductionNeutrophil and eosinophil activation and its relation to disease severity has been understudied in primary care patients with COVID-19. In this study, we investigated whether the neutrophil and eosinophil compartment were affected in primary care patients with COVID-19.MethodsCOVID-19 patients, aged ≥ 40 years with cardiovascular comorbidity presenting to the general practitioner with substantial symptoms, partaking in the COVIDSat@Home study between January and April 2021, were included. Blood was drawn during and 3 to 6 months after active COVID-19 disease and analyzed by automated flow cytometry, before and after stimulation with a formyl-peptide (fNLF). Mature neutrophil and eosinophil markers at both time points were compared to healthy controls. A questionnaire was conducted on disease symptoms during and 3 to 6 months after COVID-19 disease.ResultsThe blood of 18 COVID-19 patients and 34 healthy controls was analyzed. During active COVID-19 disease, neutrophils showed reduced CD10 (p = 0.0360), increased CD11b (p = 0.0002) and decreased CD62L expression (p < 0.0001) compared to healthy controls. During active COVID-19 disease, fNLF stimulated neutrophils showed decreased CD10 levels (p < 0.0001). Three to six months after COVID-19 disease, unstimulated neutrophils showed lowered CD62L expression (p = 0.0003) and stimulated neutrophils had decreased CD10 expression (p = 0.0483) compared to healthy controls. Both (un)stimulated CD10 levels increased 3 to 6 months after active disease (p = 0.0120 and p < 0.0001, respectively) compared to during active disease. Eosinophil blood counts were reduced during active COVID-19 disease and increased 3 to 6 months after infection (p < 0.0001). During active COVID-19, eosinophils showed increased unstimulated CD11b (p = 0.0139) and decreased (un)stimulated CD62L expression (p = 0.0036 and p = 0.0156, respectively) compared to healthy controls. Three to six months after COVID-19 disease, (un)stimulated eosinophil CD62L expression was decreased (p = 0.0148 and p = 0.0063, respectively) and the percentage of CD11bbright cells was increased (p = 0.0083 and p = 0.0307, respectively) compared to healthy controls.ConclusionAutomated flow cytometry analysis reveals specific mature neutrophil and eosinophil activation patterns in primary care patients with COVID-19 disease, during and 3 to 6 months after active disease. This suggests that the neutrophil and eosinophil compartment are long-term affected by COVID-19 in primary care patients. This indicates that these compartments may be involved in the pathogenesis of long COVID.

Background: During the course of the pandemic, home or remote monitoring of COVID-19 patients with pulse oximetry took off, but evidence on its use is scarce. Aim: To assess the feasibility of home monitoring by pulse oximetry of patients aged ≥40 years with cardiovascular comorbidity and moderate-severe COVID-19. Design and Setting: A primary care-based, open, randomised controlled pilot trial with nested process evaluation. Method: From December 2020 to June 2021, eligible patients presenting to one of 14 Dutch general practices were randomly allocated to regular measurement of peripheral oxygen saturation (at least 3 SpO2 measurements/day for 14 days) with a validated pulse oximeter or usual care. Results: All 41 participants (21 intervention, 20 usual care) completed the 45-day follow-up period. Overall, the intervention group performed 97.6% of protocolised measurements; median daily measurement/participant: 2.7 (interquartile range 1-4). Hypoxemia (SpO2<94%) was reported in ten participants (in 52 measurements). Of those, six consulted the general practitioner as instructed. Participants reported a high feeling of safety (0-100 visual analogue scale): 71.8 intervention vs. 59.8 control (p=0.09). Primary care consultations were similar across groups: 50 intervention vs. 51 control. Ten participants visited the emergency department (7 intervention vs. 3 control) of which six were hospitalised (5 intervention vs. 1 control). No participants were admitted to the ICU or died during follow-up. Conclusions: Home monitoring of moderate-severe COVID-19 patients by pulse oximetry appeared feasible; adherence was high, patients reported a high feeling of safety, while the number of primary care consultations remained similar to usual care.

Samenvatting Het veilig volgen van patiënten met COVID-19 vormt een uitdaging voor huisartsen, omdat de klinische conditie en lage zuurstofsaturatie niet altijd synchroon lopen met de ernst van de klachten. Het systematisch thuis meten van de zuurstofsaturatie door de patiënt kan uitkomst bieden. Wetenschappelijke onderbouwing hiervoor ontbreekt echter. In deze pilot onderzoeken we de haalbaarheid van thuismonitoring van zuurstofsaturatie met pulsoximetrie.