Treatable traits for long COVID

The roles of the kynurenine pathway in COVID-19 neuropathogenesis

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the highly contagious respiratory disease Corona Virus Disease 2019 (COVID-19) that may lead to various neurological and psychological disorders that can be acute, lasting days to weeks or months and possibly longer. The latter is known as long-COVID or more recently post-acute sequelae of COVID (PASC). During acute COVID-19 infection, a strong inflammatory response, known as the cytokine storm, occurs in some patients. The levels of interferon-γ (IFN-γ), interferon-β (IFN-β), interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α) are particularly increased. These cytokines are known to activate the enzyme indoleamine 2,3-dioxygenase 1 (IDO-1), catalysing the first step of tryptophan (Trp) catabolism through the kynurenine pathway (KP) leading to the production of several neurotoxic and immunosuppressive metabolites. There is already data showing elevation in KP metabolites both acutely and in PASC, especially regarding cognitive impairment. Thus, it is likely that KP involvement is significant in SARS-CoV-2 pathogenesis especially neurologically.

Effects of rehabilitation interventions for old adults with long COVID: A systematic review and meta-analysis of randomised controlled trials

Background

There is limited evidence on the effectiveness of the existing rehabilitation interventions for old adults with long coronavirus disease (COVID), which is of particular concern among old adults.

Methods

We systematically searched studies published in PubMed, EMBASE, Web of Science, Scopus, and Cochrane Library databases from their inception to 15 November 2023. Randomised controlled trials (RCTs) compared rehabilitation interventions with other controls in old adults (mean/median age of 60 or older) with long COVID were included. We performed a meta-analysis to compare the effects of the rehabilitation interventions with the common control group. Mean difference (MD) or standardised mean difference (SMD) with its 95% confidence intervals (CI) were used as summary statistics. Moreover, subgroup analyses based on the intervention programmes, the severity of acute infection, and the age of participants were carried out.

Results

A total of 11 RCTs involving 832 participants (64.37 ± 7.94 years, 52.2% were men) were included in the analysis. Compared with the control groups, rehabilitation interventions significantly improved 6-minute walking test (6 MWT; MD = 15.77 metres (m), 95% CI = 5.40, 26.13, P < 0.01), 30-second sit-to-stand test (MD = 4.11 number of stands (n), 95% CI = 2.46, 5.76, P < 0.001), all aspects of quality of life, independence in activities of daily living (SMD = 0.31, 95% CI = 0.14, 0.48, P < 0.001), and relieved fatigue (SMD = -0.66, 95% CI = -1.13, -0.19, P < 0.01), depression (SMD = -0.89, 95% CI = -1.76, -0.02, P < 0.05) and anxiety (SMD = -0.81, 95% CI = -1.58, -0.05, P < 0.05). However, the improvement of hand grip strength and pulmonary function was not statistically significant (P > 0.05). Subgroup analyses showed that improvements in 6 MWT, fatigue, anxiety, and depression were more pronounced in old patients who received exercise training, while those who received respiratory rehabilitation had more pronounced improvements in pulmonary function and quality of life.

Conclusions

Old adults with long COVID who underwent rehabilitation interventions experienced significant improvement in functional capacity, fatigue, quality of life, independence in activities of daily living, and mental health outcomes compared with usual/standard care. These findings suggest that screening, management, and rehabilitation interventions for long COVID in older adults should be strengthened to improve their complete health status and functional status, thereby reducing the long-term disease burden caused by long COVID and fostering healthy aging during the post-pandemic era.

Long COVID: a clinical update

Post-COVID-19 condition (also known as long COVID) is generally defined as symptoms persisting for 3 months or more after acute COVID-19. Long COVID can affect multiple organ systems and lead to severe and protracted impairment of function as a result of organ damage. The burden of this disease, both on the individual and on health systems and national economies, is high. In this interdisciplinary Review, with a coauthor with lived experience of severe long COVID, we sought to bring together multiple streams of literature on the epidemiology, pathophysiology (including the hypothesised mechanisms of organ damage), lived experience and clinical manifestations, and clinical investigation and management of long COVID. Although current approaches to long COVID care are largely symptomatic and supportive, recent advances in clinical phenotyping, deep molecular profiling, and biomarker identification might herald a more mechanism-informed and personally tailored approach to clinical care. We also cover the organisation of services for long COVID, approaches to preventing long COVID, and suggestions for future research.

Prevalence of Long COVID and the Impact on Diabetes Management and Physical Activity Participation in Adults With Type 2 Diabetes: An Australia-wide Cross-sectional Online Survey

OBJECTIVES

The aim of this research was to understand the prevalence and impact of long COVID on adults with type 2 diabetes (T2D). Specifically, we sought to identify the proportion of adults with T2D who have had COVID-19 and experienced long COVID symptoms. We also explored how these ongoing symptoms impact diabetes management and physical activity participation.

METHODS

Our study was carried out using an online survey of adults in Australia with T2D who had confirmed COVID-19 ≥12 weeks before participation. Respondents were asked to report the presence (and severity) of long COVID-19 symptoms, and, for those with long COVID, the impact of their symptoms on diabetes management (blood glucose, body weight) and physical activity participation (activities of daily living, work/study, exercise).

RESULTS

Survey responses were provided by 1,046 adults with T2D (median age 61.0 [interquartile range 49.8 to 70.0] years; 56.0% men, 42.1% women, and 1% nonbinary/transgender; median T2D duration 10.0 [5.0 to 18.0] years and median time since COVID-19 infection 33.0 [20.3 to 36.1] weeks). Almost one third (30%) of respondents reported long COVID symptoms (present ≥12 weeks after most recent infection); 40% of respondents with long COVID symptoms reported a worsening of their diabetes management since their COVID-19 infection, with 29% reporting trouble controlling their blood glucose and 43% reporting a higher body weight. Two thirds of respondents with ongoing symptoms reported that these symptoms moderately to severely impacted their ability to perform activities of daily living, work, and/or exercise. The majority of those with long COVID reported reducing the frequency, duration, and/or intensity of exercise since their COVID-19 infection, with 36.1% not yet returning to their preinfection exercise levels; 66% cited ongoing symptoms as the primary reason for these limitations.

CONCLUSIONS

Physical activity is a crucial component of diabetes management. However, the high prevalence of long COVID is hindering participation in this population, as well as deleteriously impacting diabetes management. Developing strategies to support adults with T2D and long COVID to recommence safe levels of physical activity is of critical importance.

Clinical Characterization of New-Onset Chronic Musculoskeletal Pain in Long COVID: A Cross-Sectional Study

Purpose

New-onset chronic musculoskeletal (MSK) pain is one of the common persistent symptoms in Long COVID (LC). This study investigated its clinical characteristics, underlying mechanisms, and impact on function, psychological health, and quality of life.

Patients and Methods

Thirty adults (19 female, 11 male) with LC and new-onset chronic MSK pain underwent clinical examination, Quantitative Sensory Testing (QST), and blood tests for inflammatory markers and completed the following outcome measures: Timed Up and Go test (TUG), handgrip strength test, COVID-19 Yorkshire Rehabilitation Scale (C19-YRS), Brief Pain Inventory (BPI), Pain Self-Efficacy Questionnaire (PSEQ), Pain Catastrophizing Scale (PCS), International Physical Activity Questionnaire-short form (IPAQ-sf), Generalized Anxiety Disorder (GAD-7), Patient Health Questionnaire (PHQ-9), and EuroQol Five Dimensions health-related quality of life (EQ-5D-5L).

Results

New-onset chronic MSK pain was widespread and continuous in nature, and worse in the joints. When compared to normative values reported in the literature: a) QST revealed mechanical hyperalgesia, heightened temporal summation of pain, and hypoesthesia to vibration stimuli, which is strongly suggestive of central sensitization; b) Plasma cytokine assays indicated distinct pro-inflammatory profiles; c) TUG time indicated reduced balance and mobility; d) handgrip strength revealed general weakness; e) physical activity was lower; and f) there were moderate levels of depression and anxiety with lower self-efficacy scores and lower levels of pain catastrophizing. LC symptoms were of moderate severity (44.8/100), moderate functional disability (22.8/50) and severely compromised overall health (2.6/10) when compared to pre-COVID scores.

Conclusion

New-onset chronic MSK pain in LC tends to be widespread, constant, and associated with weakness, reduced function, depression, anxiety, and reduced quality of life. There is associated central sensitization and proinflammatory state in the condition. Further research is essential to explore the longitudinal progression and natural evolution of the new-onset chronic MSK pain in LC.

Developing a clinical-pathological framework of long COVID-related fatigue applied to public safety workers

In the wake of the COVID-19 pandemic, millions worldwide are still struggling with persistent or recurring symptoms known as long COVID. Fatigue is one of the most prevalent symptoms associated with long COVID, and for many it can be debilitating. Understanding the potential pathological processes that link fatigue to long COVID is critical to better guide treatment. Challenges with diagnosis and treatment are reviewed, recognizing that post-COVID fatigue does not always present with corroborating clinical evidence, a situation that is frustrating for both patients and healthcare providers. Firefighters are a group of public safety workers who are particularly impacted by long COVID-related fatigue. Firefighters must be able to engage in strenuous physical activity and deal with demanding psychological situations, both of which may be difficult for those suffering from fatigue. Disruption in public safety worker health can potentially impact community welfare. This review creates a framework to explain the clinical-pathological features of fatigue resulting from long COVID, addresses diagnosis and treatment challenges, and explores the unique impact fatigue may pose for public safety workers and their organizations.

Long COVID management: a mini review of current recommendations and underutilized modalities

Long COVID is a condition that develops in a subset of patients after COVID-19 infection comprising of symptoms of varying severity encompassing multiple organ systems. Currently, long COVID is without consensus on a formal definition, identifiable biomarkers, and validated treatment. Long COVID is expected to be a long-term chronic condition for a subset of patients and is associated with suffering and incapacity. There is an urgent need for clear management guidelines for the primary care provider, who is essential in bridging the gap with more specialized care to improve quality of life and functionality in their patients living with long COVID. The purpose of this mini review is to provide primary care providers with the latest highlights from existing literature regarding the most common long COVID symptoms and current management recommendations. This review also highlights the underutilized interventions of stellate ganglion blocks and low-dose naltrexone, both with well-established safety profiles demonstrated to improve quality of life and functionality for patients suffering with some symptoms of long COVID, and encourages prompt referral to interventional pain management.

Diaphragmatic strengthening exercises for patients with post COVID-19 condition after mild-to-moderate acute COVID-19 infection: a randomized controlled study

OBJECTIVE

To assess the clinical effects of incentive spirometry (IS) and diaphragmatic breathing (DB) in patients with post COVID-19 condition and diaphragmatic dysfunction as compared with the standard care alone.

METHODS

The present longitudinal randomized study included 60 patients with post COVID-19 condition and diaphragmatic dysfunction. Patients were equally randomized to receive standard care plus IS (G1), standard care plus DB (G2) or standard care alone (G3) for 8 weeks. The primary outcome is clinical improvement as evaluated by the modified Medical Research Council (mMRC) dyspnoea scale.

RESULTS

Comparison between the studied groups revealed significant improvement in G1 and G2 in all parameters at the end of follow-up. However, no significant improvement was found in G3. At the end of follow-up, 15 patients (75.0%) in G1, 11 patients (55.0%) in G2, and 3 patients (15.0%) in G3 showed improvement on the mMRC dyspnoea scale. Multivariate logistic regression analysis identified mild acute COVID-19 infection (p = 0.009), use of IS (p < 0.001), and use of DB (p = 0.023) as significant predictors of improvement on the mMRC dyspnoea scale.

CONCLUSIONS

IS or DB training in addition to the standard care in post COVID-19 condition was associated with better clinical improvement as compared with the standard care alone.

Treatable Traits in Asthma: The Importance of Extrapulmonary Traits-GERD, CRSwNP, Atopic Dermatitis, and Depression/Anxiety

Treatable traits is a personalized medicine approach to the management of airway disease. Assessing traits within the 3 domains of pulmonary, extrapulmonary, and behavioral/lifestyle/risk factor traits, and applying targeted treatments to effectively manage these traits, enables a holistic and personalized approach to care. Asthma is a heterogeneous and complex airway disease that is frequently complicated by several extrapulmonary traits that impact asthma outcomes and predict future outcomes. We propose that the identification of extrapulmonary and behavioral risk factor traits and the implementation of targeted therapy will lead to improved management of people with asthma. Furthermore, many extrapulmonary traits present as "connected comorbidities"; that is, they coexist with asthma, have an impact on asthma, and effective treatment improves both asthma and the comorbidity or the comorbidities may share a similar mechanism. In this review, we explore this concept and look at atopic dermatitis, chronic rhinosinusitis with nasal polyps, gastroesophageal reflux disease, anxiety, and depression as treatable traits of asthma and how these can be managed using this approach.

Treatable traits models of care

Treatable traits is a personalized approach to the management of respiratory disease. The approach involves a multidimensional assessment to understand the traits present in individual patients. Traits are phenotypic and endotypic characteristics that can be identified, are clinically relevant and can be successfully treated by therapy to improve clinical outcomes. Identification of traits is followed by individualized and targeted treatment to those traits. First proposed for the management of asthma and chronic obstructive pulmonary disease (COPD) the approach is recommended in many other areas of respiratory and now immunology medicine. Models of care for treatable traits have been proposed in different diseases and health care setting. In asthma and COPD traits are identified in three domains including pulmonary, extrapulmonary and behavioural/lifestyle/risk-factors. In bronchiectasis and interstitial lung disease, a fourth domain of aetiological traits has been proposed. As the core of treatable traits is personalized and individualized medicine; there are several key aspects to treatable traits models of care that should be considered in the delivery of care. These include person centredness, consideration of patients' values, needs and preferences, health literacy and engagement. We review the models of care that have been proposed and provide guidance on the engagement of patients in this approach to care.

Reduced Fatigue Symptoms in the Post-COVID Syndrome With Amifampridine: A Collective Casuistry With Double-Blind Discontinuation Trials

After a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, approximately 10-20% of patients are affected by the post-COVID syndrome (PCS). This condition leads to a variety of functional complaints, including symptoms of fatigue. To date, there is still no adequate treatment option. Five patients are presented, including the self-observation of one of the authors, in whom the administration of amifampridine as an "off-label use" led to a normalization of the unphysiologically increased need for sleep with a simultaneous increase in the Bell score. This effect was confirmed in a double-blind discontinuation trial (the medication was discontinued on a trial basis) in two of the patients. The five patients, who were previously unable to lead a normal life due to their fatigue symptoms, were able to return to everyday life after treatment with amifampridine. This offers hope to millions of affected patients.