[Organ-specific sequelae of COVID-19 in adults]

Blood T cell phenotypes correlate with fatigue severity in post-acute sequelae of COVID-19

PURPOSE

Post-acute sequelae of COVID-19 (PASC) affect approximately 10% of convalescent patients. The spectrum of symptoms is broad and heterogeneous with fatigue being the most often reported sequela. Easily accessible blood biomarkers to determine PASC severity are lacking. Thus, our study aimed to correlate immune phenotypes with PASC across the severity spectrum of COVID-19.

METHODS

A total of 176 originally immunonaïve, convalescent COVID-19 patients from a prospective cohort during the first pandemic phase were stratified by initial disease severity and underwent clinical, psychosocial, and immune phenotyping around 10 weeks after first COVID-19 symptoms. COVID-19-associated fatigue dynamics were assessed and related to clinical and immune phenotypes.

RESULTS

Fatigue and severe fatigue were commonly reported irrespective of initial COVID-19 severity or organ-specific PASC. A clinically relevant increase in fatigue severity after COVID-19 was detected in all groups. Neutralizing antibody titers were higher in patients with severe acute disease, but no association was found between antibody titers and PASC. While absolute peripheral blood immune cell counts in originally immunonaïve PASC patients did not differ from unexposed controls, peripheral CD3+CD4+ T cell counts were independently correlated with fatigue severity across all strata in multivariable analysis.

CONCLUSIONS

Patients were at similar risk of self-reported PASC irrespective of initial disease severity. The independent correlation between fatigue severity and blood T cell phenotypes indicates a possible role of CD4+ T cells in the pathogenesis of post-COVID-19 fatigue, which might serve as a blood biomarker.

Pulmonale Manifestationen bei Long-COVID

Hintergrund

Pulmonale Manifestationen sind sehr häufige Folgeerscheinungen nach einer Severe-acute-respiratory-syndrome-coronavirus-type-2(SARS-CoV-2)-Infektion, die unter dem Begriff Long-COVID-Syndrom (COVID „coronavirus disease“) zusammengefasst werden.

Ziel und Methoden

Zusammenfassung der aktuellen Literatur zu den pulmonalen Manifestationen mit einem Fokus auf Expertenempfehlungen.

Ergebnisse

Dyspnoe ist nach der chronischen Fatigue das häufigste Symptom bei Patienten mit Long-COVID-Syndrom. Auffällige Befunde finden sich vor allem nach schwerem akutem COVID-19-Verlauf und beinhalten radiologische Veränderungen im Sinne interstitieller Lungenerkrankungen, restriktive lungenfunktionelle Befunde und Einschränkungen der Diffusionskapazität als häufigsten pathologischen Befund. Obwohl sich sowohl Beschwerden als auch pathologische pulmonale Befunde im Verlauf bessern, können einige Patienten noch Monate nach der akuten Infektion unter Auffälligkeiten leiden. Dabei ist die Relevanz der pathologischen Befunde sowie eine Beteiligung funktioneller respiratorischer Einschränkungen, einer kardiopulmonalen Dekonditionierung, nichtsomatischer Ursachen und vorbestehender Erkrankungen aktuell unklar. Die diagnostische Abklärung fokussiert entsprechend auf Risikopatienten und schließt neben einer bildgebenden und lungenfunktionellen Abklärung eine Belastungsuntersuchung und bei unklaren Befunden eine Echokardiographie zur Diagnose einer pulmonalvaskulären Komponente ein. Die therapeutischen Möglichkeiten beinhalten aktuell die leitliniengerechte Therapie von Ursachen der Beschwerden (beispielsweise interstitielle Lungenerkrankungen, Husten) und Rehabilitationsmaßnahmen.

Schlussfolgerung

Das aktuelle Wissen zum Krankheitsbild wird ständig erweitert, allerdings existieren aufgrund mangelnder Studienlage noch keine evidenzbasierten Leitlinien zur Diagnostik und Therapie pulmonaler Manifestationen beim Long-COVID-Syndrom.

Respiratory muscle dysfunction in long-COVID patients

Purpose

Symptoms often persistent for more than 4 weeks after COVID-19—now commonly referred to as ‘Long COVID’. Independent of initial disease severity or pathological pulmonary functions tests, fatigue, exertional intolerance and dyspnea are among the most common COVID-19 sequelae. We hypothesized that respiratory muscle dysfunction might be prevalent in persistently symptomatic patients after COVID-19 with self-reported exercise intolerance.

Methods

In a small cross-sectional pilot study (n = 67) of mild-to-moderate (nonhospitalized) and moderate-to-critical convalescent (formerly hospitalized) patients presenting to our outpatient clinic approx. 5 months after acute infection, we measured neuroventilatory activity P0.1, inspiratory muscle strength (PImax) and total respiratory muscle strain (P0.1/PImax) in addition to standard pulmonary functions tests, capillary blood gas analysis, 6 min walking tests and functional questionnaires.

Results

Pathological P0.1/PImax was found in 88% of symptomatic patients. Mean PImax was reduced in hospitalized patients, but reduced PImax was also found in 65% of nonhospitalized patients. Mean P0.1 was pathologically increased in both groups. Increased P0.1 was associated with exercise-induced deoxygenation, impaired exercise tolerance, decreased activity and productivity and worse Post-COVID-19 functional status scale. Pathological changes in P0.1, PImax or P0.1/PImax were not associated with pre-existing conditions.

Conclusions

Our findings point towards respiratory muscle dysfunction as a novel aspect of COVID-19 sequelae. Thus, we strongly advocate for systematic respiratory muscle testing during the diagnostic workup of persistently symptomatic, convalescent COVID-19 patients.

Epipharyngeal Abrasive Therapy (EAT) Has Potential as a Novel Method for Long COVID Treatment

COVID-19 often causes sequelae after initial recovery, referred to collectively as long COVID. Long COVID is considered to be caused by the persistence of chronic inflammation after acute COVID-19 infection. We found that all long COVID patients had residual inflammation in the epipharynx, an important site of coronavirus replication, and some long COVID symptoms are similar to those associated with chronic epipharyngitis. Epipharyngeal abrasive therapy (EAT) is a treatment for chronic epipharyngitis in Japan that involves applying zinc chloride as an anti-inflammatory agent to the epipharyngeal mucosa. In this study, we evaluated the efficacy of EAT for the treatment of long COVID. The subjects in this study were 58 patients with long COVID who were treated with EAT in the outpatient department once a week for one month (mean age = 38.4 ± 12.9 years). The intensities of fatigue, headache, and attention disorder, which are reported as frequent symptoms of long COVID, were assessed before and after EAT using the visual analog scale (VAS). EAT reduced inflammation in the epipharynx and significantly improved the intensity of fatigue, headache, and attention disorder, which may be related to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). These results suggest that EAT has potential as a novel method for long COVID treatment.