Characterizing long-COVID brain fog: a retrospective cohort study.

BACKGROUND: Long COVID or post-COVID condition (PCC) is a common complication following acute COVID-19 infection. PCC is a multi-systems disease with neurocognitive impairment frequently reported regardless of age. Little is known about the risk factors, associated biomarkers and clinical trajectory of patients with this symptom. OBJECTIVE: To determine differences in clinical risk factors, associated biochemical markers and longitudinal clinical trajectories between patients with PCC with subjective neurocognitive symptoms (NC+) or without (NC-). METHODS: A retrospective longitudinal cohort study was performed using a well-characterized provincial database of patients with clinically confirmed PCC separated into NC+ and NC- cohorts. Demographical, clinical and biochemical differences at initial consultation between the two patient cohorts were analyzed in cross-section. Multivariate regression analyses were conducted to identify independent risk factors for neurocognitive impairment. Determination of the recovery trajectory was performed using serial assessments of the patient-reported health-related quality of life (HR-QoL) metric Eq-5D-5L-vas score. FINDINGS: Women, milder acute infection and pre-existing mental health diagnoses were independently associated with subjective neurocognitive impairment at 8 months post-infection. NC + patients demonstrated lower levels of IgG, IgG1 and IgG3 compared to NC- patients. The NC + cohort had poorer HR-QoL at initial consultation 8 months post-infection with gradual improvement over 20 months post-infection. CONCLUSIONS: Neurocognitive impairment represents a severe phenotype of PCC, associated with unique risk factors, aberrancy in immune response and a delayed recovery trajectory. Those with risk factors for neurocognitive impairment can be identified early in the disease trajectory for more intense medical follow-up.

Reliability and validity of the post COVID-19 condition stigma questionnaire: A prospective cohort study.

Background: Many of the 10-20% percent of COVID-19 survivors who develop Post COVID-19 Condition (PCC, or Long COVID) describe experiences suggestive of stigmatization, a known social determinant of health. Our objective was to develop an instrument, the Post COVID-19 Condition Stigma Questionnaire (PCCSQ), with which to quantify and characterise PCC-related stigma. Methods: We conducted a prospective cohort study to assess the reliability and validity of the PCCSQ. Patients referred to our Post COVID-19 Clinic in the Canadian City of Edmonton, Alberta between May 29, 2021 and May 24, 2022 who met inclusion criteria (attending an academic post COVID-19 clinic; age ≥18 years; persistent symptoms and impairment at ≥ 12 weeks since PCR positive acute COVID-19 infection; English-speaking; internet access; consenting) were invited to complete online questionnaires, including the PCCSQ. Analyses were conducted to estimate the instrument's reliability, construct validity, and association with relevant instruments and defined health outcomes. Findings: Of the 198 patients invited, 145 (73%) met inclusion criteria and completed usable questionnaires. Total Stigma Score (TSS) on the PCCSQ ranged from 40 to 174/200. The mean (SD) was 103.9 (31.3). Cronbach's alpha was 0.97. Test-retest reliability was 0.92. Factor analysis supported a 6-factor latent construct. Subtest reliabilities were >0.75. Individuals reporting increased TSS occurred across all demographic groups. Increased risk categories included women, white ethnicity, and limited educational opportunities. TSS was positively correlated with symptoms, depression, anxiety, loneliness, reduced self-esteem, thoughts of self-harm, post-COVID functional status, frailty, EQ5D5L score, and number of ED visits. It was negatively correlated with perceived social support, 6-min walk distance, and EQ5D5L global rating. Stigma scores were significantly increased among participants reporting employment status as disabled. Interpretation: Our findings suggested that the PCCSQ is a valid, reliable tool with which to estimate PCC-related stigma. It allows for the identification of patients reporting increased stigma and offers insights into their experiences. Funding: The Edmonton Post COVID-19 Clinic is supported by the University of Alberta and Alberta Health Services. No additional sources of funding were involved in the execution of this research study.

Persistent dyspnea after COVID-19 is not related to cardiopulmonary impairment; a cross-sectional study of persistently dyspneic COVID-19, non-dyspneic COVID-19 and controls.

Background: Up to 53% of individuals who had mild COVID-19 experience symptoms for >3-month following infection (Long-CoV). Dyspnea is reported in 60% of Long-CoV cases and may be secondary to impaired exercise capacity (VO2peak) as a result of pulmonary, pulmonary vascular, or cardiac insult. This study examined whether cardiopulmonary mechanisms could explain exertional dyspnea in Long-CoV. Methods: A cross-sectional study of participants with Long-CoV (n = 28, age 40 ± 11 years, 214 ± 85 days post-infection) and age- sex- and body mass index-matched COVID-19 naïve controls (Con, n = 24, age 41 ± 12 years) and participants fully recovered from COVID-19 (ns-CoV, n = 14, age 37 ± 9 years, 198 ± 89 days post-infection) was conducted. Participants self-reported symptoms and baseline dyspnea (modified Medical Research Council, mMRC, dyspnea grade), then underwent a comprehensive pulmonary function test, cardiopulmonary exercise test, exercise pulmonary diffusing capacity measurement, and rest and exercise echocardiography. Results: VO2peak, pulmonary function and cardiac/pulmonary vascular parameters were not impaired in Long- or ns-CoV compared to normative values (VO2peak: 106 ± 25 and 107 ± 25%predicted, respectively) and cardiopulmonary responses to exercise were otherwise normal. When Long-CoV were stratified by clinical dyspnea severity (mMRC = 0 vs mMRC≥1), there were no between-group differences in VO2peak. During submaximal exercise, dyspnea and ventilation were increased in the mMRC≥1 group, despite normal operating lung volumes, arterial saturation, diffusing capacity and indicators of pulmonary vascular pressures. Interpretation: Persistent dyspnea after COVID-19 was not associated with overt cardiopulmonary impairment or exercise intolerance. Interventions focusing on dyspnea management may be appropriate for Long-CoV patients who report dyspnea without cardiopulmonary impairment.

The effectiveness of pulmonary rehabilitation for Post-COVID symptoms: A rapid review of the literature.

BACKGROUND: Multi-disciplinary rehabilitation is recommended for individuals with post-acute sequelae of COVID-19 infection (i.e., symptoms 3-4 weeks after acute infection). There are emerging reports of use of pulmonary rehabilitation (PR) in the post-acute stages of COVID-19, however the appropriateness of PR for managing post-COVID symptoms remains unclear. To offer practical guidance with regards to post-COVID PR, a greater understanding of the clinical effectiveness literature is required. METHODS: A rapid review of the published literature was completed. An electronic database search of the literature published between July 1, 2020 and June 1, 2021 was performed in MEDLINE, Pubmed, and EMBASE. Primary studies evaluating the clinical effectiveness of PR for individuals with post-COVID symptoms were included. RESULTS: Nine studies evaluating the effectiveness of PR were identified; most were small, experimental or quasi-experimental studies, including 1 RCT, and were primarily of low quality. After attending PR, all studies reported improvements in exercise capacity, pulmonary function, and/or quality of life for individuals with post-COVID symptoms who had been hospitalized for their acute COVID-19 infection. Few studies evaluated changes in post-COVID symptom severity or frequency and, of these, improvements in dyspnea, fatigue, anxiety and depression were observed following PR. Further, no studies evaluated non-hospitalized patients or long-term outcomes beyond 3 months after initiating PR. CONCLUSIONS: With limited high-quality evidence, any recommendations or practical guidance for PR programmes for those with post-COVID symptoms should consider factors such as feasibility, current PR capacity, and resource constraints.

COVID-19 hospitalization is associated with pulmonary/diffusion abnormalities but not post-acute sequelae of COVID-19 severity.

Coronavirus disease-19 (COVID-19) has resulted in much acute morbidity and mortality worldwide. There is now a growing recognition of the post-acute sequela of COVID-19, termed long COVID. However, the risk factors contributing to this condition remain unclear. Here, we address the growing controversy in the literature of whether hospitalization is a risk factor for long COVID. We found that hospitalization is associated with worse pulmonary restriction and reduction in diffusion capacity at 3 months post-infection. However, the impact on mental health, functional and quality of life is equally severe in those who have and have not been hospitalized during the acute infection. These findings suggest that hospitalization is a risk factor for pulmonary complications of long COVID but not the overall severity of long COVID.

Exertional intolerance and dyspnea with preserved lung function: an emerging long COVID phenotype?

The COVID-19 pandemic has resulted in significant acute morbidity and mortality worldwide. There is now a growing recognition of the longer-term sequelae of this infection, termed "long COVID". However, little is known about this condition. Here, we describe a distinct phenotype seen in a subset of patients with long COVID who have reduced exercise tolerance as measured by the 6 min walk test. They are associated with significant exertional dyspnea, reduced health-related quality of life and poor functional status. However, surprisingly, they do not appear to have any major pulmonary function abnormalities or increased burden of neurologic, musculoskeletal or fatigue symptoms.

Acute Cough Due to Acute Bronchitis in Immunocompetent Adult Outpatients: CHEST Expert Panel Report.

BACKGROUND: Evidence for the diagnosis and management of cough due to acute bronchitis in immunocompetent adult outpatients was reviewed as an update to the 2006 "Chronic Cough Due to Acute Bronchitis: American College of Chest Physicians (ACCP) Evidence-Based Clinical Practice Guidelines." METHODS: Acute bronchitis was defined as an acute lower respiratory tract infection manifested predominantly by cough with or without sputum production, lasting no more than 3 weeks with no clinical or any recent radiographic evidence to suggest an alternative explanation. Two clinical population, intervention, comparison, outcome questions were addressed by systematic review in July 2017: (1) the role of investigations beyond the clinical assessment of patients presenting with suspected acute bronchitis, and (2) the efficacy and safety of prescribing medication for cough in acute bronchitis. An updated search was undertaken in May 2018. RESULTS: No eligible studies relevant to the first question were identified. For the second question, only one relevant study met eligibility criteria. This study found no difference in number of days with cough between patients treated with an antibiotic or an oral nonsteroidal antiinflammatory agent compared with placebo. Clinical suggestions and research recommendations were made based on the consensus opinion of the CHEST Expert Cough Panel. CONCLUSIONS: The panelists suggested that no routine investigations be ordered and no routine medications be prescribed in immunocompetent adult outpatients first presenting with cough due to suspected acute bronchitis, until such investigations and treatments have been shown to be safe and effective at making cough less severe or resolve sooner. If the cough due to suspected acute bronchitis persists or worsens, a reassessment and consideration of targeted investigations should be considered.

Association between vitamin D status in early pregnancy and atopy in offspring in a vitamin D deplete cohort.

BACKGROUND: Vitamin D status may play a role in the development of atopic diseases due to its action on lung development and immune system development and function. AIMS: Our objective was to assess whether 25-hydroxyvitamin D (25OHD) levels in maternal blood in pregnancy were associated with atopy in children. METHODS: We analysed 279 mother-child pairs from the ROLO study conducted in Dublin, Ireland. Serum 25OHD was measured at 13 and 28 weeks of pregnancy. Development of childhood atopy was self-reported by mothers at follow-up appointments at 6 months, 2 years or 5 years. Logistic regression analysis was used to evaluate associations between maternal 25OHD status and development of atopy. RESULTS: The mean (SD) 25OHD levels in early and late pregnancy were 41.9 (19.2) nmol/L and 40.2 (21.6) nmol/L, respectively. Maternal 25OHD status in early pregnancy, but not in late pregnancy, was associated with a reduced risk of atopy at 2 years (OR 0.972, CI 0.946-0.999). In early pregnancy, those with serum 25OHD levels < 30 nmol/L compared with those with 25OHD > 50 nmol/L had significantly greater risk of developing atopy at 2 years (OR 4.76, CI 1.38-16.47). CONCLUSIONS: The development of childhood atopy may be associated with maternal vitamin D deficiency in early pregnancy among a cohort of women at risk of vitamin D deficiency. Further research is required to explore the relationship between vitamin D and atopy, particularly among women with poor vitamin D status, and whether supplementation should be prioritised in early pregnancy to reduce childhood atopy.

Paediatric and adult bronchiectasis: Diagnosis, disease burden and prognosis.

Bronchiectasis is a chronic, debilitating disease with increasing worldwide prevalence and burden. Accurate and early diagnosis is essential for both its management and prognosis. This review will discuss the diagnosis of bronchiectasis, the international burden of the disease and its current prognosis.

Validation of the Incremental Shuttle Walk Test as a Clinical End Point in Bronchiectasis.

BACKGROUND: A validated clinical end point is needed to assess response to therapies in bronchiectasis. OBJECTIVES: The goal of this study was to assess the reliability, validity, and responsiveness of the incremental shuttle walk test (ISWT) as a clinical end point in bronchiectasis. METHODS: In clinically stable patients (n = 30), the ISWT was performed twice, 6 months apart. Correlation between the St. George's Respiratory Questionnaire (SGRQ) and the ISWT (n = 94) was performed. The 1-year gentamicin study was reanalyzed to assess the area under the curve (percent change of ISWT with a ≥ 4 unit improvement in total SGRQ). ISWT was performed prior to and following 14 days of antibiotics for an exacerbation (94 oral courses and 30 IV courses, n = 124) and reanalysis of the 1-year gentamicin study (n = 57). RESULTS: The ISWT did not significantly change over 6 months while clinically stable. The ISWT correlated inversely with the SGRQ (rs = -0.60; P < .0001), Bronchiectasis Severity Index score (rs = -0.44; P < .0001), and sedentary time (rs = -0.48; P = .0007) but correlated with physical activity (rs = 0.42; P = .004). The area under the curve for percent change in ISWT with ≥ 4 unit improvement in SGRQ was 0.79 (95% CI, 0.66-0.91; P = .001). A threshold of 5% improvement in the ISWT had a 92% sensitivity but 50% specificity, and from the responsiveness studies would capture 73% of all patients. CONCLUSIONS: This study confirmed the ISWT to be reliable, valid, and responsive to change in patients with bronchiectasis. The authors propose that a minimum clinically important difference of 5% improvement in the ISWT would be a useful objective end point to assess therapies in bronchiectasis.

British Thoracic Society guideline for bronchiectasis in adults.

The full British Thoracic Society Guideline for Bronchiectasis in Adults is published in Thorax. The following is a summary of the recommendations and good practice points. The sections referred to in the summary refer to the full guideline. The appendices are available in the full guideline.

Delayed neutrophil apoptosis enhances NET formation in cystic fibrosis.

BACKGROUND: Cystic fibrosis (CF) lung disease is defined by large numbers of neutrophils and associated damaging products in the airway. Delayed neutrophil apoptosis is described in CF although it is unclear whether this is a primary neutrophil defect or a response to chronic inflammation. Increased levels of neutrophil extracellular traps (NETs) have been measured in CF and we aimed to investigate the causal relationship between these phenomena and their potential to serve as a driver of inflammation. We hypothesised that the delay in apoptosis in CF is a primary defect and preferentially allows CF neutrophils to form NETs, contributing to inflammation. METHODS: Blood neutrophils were isolated from patients with CF, CF pigs and appropriate controls. Neutrophils were also obtained from patients with CF before and after commencing ivacaftor. Apoptosis was assessed by morphology and flow cytometry. NET formation was determined by fluorescent microscopy and DNA release assays. NET interaction with macrophages was examined by measuring cytokine generation with ELISA and qRT-PCR. RESULTS: CF neutrophils live longer due to decreased apoptosis. This was observed in both cystic fibrosis transmembrane conductance regulator (CFTR) null piglets and patients with CF, and furthermore was reversed by ivacaftor (CFTR potentiator) in patients with gating (G551D) mutations. CF neutrophils formed more NETs and this was reversed by cyclin-dependent kinase inhibitor exposure. NETs provided a proinflammatory stimulus to macrophages, which was enhanced in CF. CONCLUSIONS: CF neutrophils have a prosurvival phenotype that is associated with an absence of CFTR function and allows increased NET production, which can in turn induce inflammation. Augmenting neutrophil apoptosis in CF may allow more appropriate neutrophil disposal, decreasing NET formation and thus inflammation.

The use of fructosamine in cystic fibrosis-related diabetes (CFRD) screening.

OBJECTIVE: To determine whether serum fructosamine correlates with glycemic control and clinical outcomes in patients being screened for cystic fibrosis-related diabetes (CFRD). METHODS: Fructosamine and percent predicted forced expiratory volume in 1s (FEV1) were measured in patients undergoing a 2h oral glucose tolerance test (OGTT) for CFRD screening. Fractional serum fructosamine (FSF) was calculated as fructosamine/total protein. RESULTS: FSF exhibited a positive correlation with 2h OGTT results (r2=0.3201, p=0.009), and ROC curve analysis suggested that FSF can identify patients with an abnormal OGTT (AUC=0.840, p=0.0002). FSF also exhibited a negative correlation with FEV1 (r2=0.3732, p=0.035). Patients with FSF≥3.70µmol/g had significantly lower FEV1 (median 47%) compared to those with FSF<3.70µmol/g (median 90%; p=0.015). CONCLUSIONS: FSF correlated with both OGTT results and FEV1, and reliably identified patients with abnormal OGTT results. This simple blood test shows potential as an effective tool in CFRD screening.

Diagnosis and management of bronchiectasis.

KEY POINTS Following a diagnosis of bronchiectasis, it is important to investigate for an underlying cause. Goals of management are to suppress airway infection and inflammation, to improve symptoms and health-related quality of life. There are now validated scoring tools to help assess disease severity, which can help to stratify management. Good evidence supports the use of both exercise training and long-term macrolide therapy in long-term disease management.

A prospective cohort study of the use of domiciliary intravenous antibiotics in bronchiectasis.

BACKGROUND: We introduced domiciliary intravenous (IV) antibiotic therapy in patients with bronchiectasis to promote patient-centred domiciliary treatment instead of hospital inpatient treatment. AIM: To assess the efficacy and safety of domiciliary IV antibiotic therapy in patients with non-cystic fibrosis bronchiectasis. METHODS: In this prospective study conducted over 5 years, we assessed patients' eligibility for receiving domiciliary treatment. All patients received 14 days of IV antibiotic therapy and were monitored at baseline/day 7/day 14. We assessed the treatment outcome, morbidity, mortality and 30-day readmission rates. RESULTS: A total of 116 patients received 196 courses of IV antibiotics. Eighty courses were delivered as inpatient treatment, 32 as early supported discharge (ESD) and 84 as domiciliary therapy. There was significant clinical and quality of life improvement in all groups, with resolution of infection in 76% in the inpatient group, 80% in the ESD group and 80% in the domiciliary group. Morbidity was recorded in 13.8% in the inpatient group, 9.4% in the ESD group and 14.2% in the domiciliary IV group. No mortality was recorded in either group. Thirty-day readmission rates were 13.8% in the inpatient group, 12.5% in the ESD group and 14.2% in the domiciliary group. Total bed days saved was 1443. CONCLUSION: Domiciliary IV antibiotic therapy in bronchiectasis is clinically effective and was safe in our cohort of patients.

Mannose-binding lectin deficiency and disease severity in non-cystic fibrosis bronchiectasis: a prospective study.

BACKGROUND: Mannose-binding lectin (MBL) is a key component of innate immunity. MBL deficiency is common (10-30% of the general population depending on the definition used) and has been associated with disease progression in cystic fibrosis. We aimed to assess the effect of MBL deficiency on disease severity in non-cystic fibrosis bronchiectasis. METHODS: We recruited patients with non-cystic fibrosis bronchiectasis and age-matched and sex-matched controls at a specialist bronchiectasis clinic in Edinburgh, UK. We assessed MBL function with genotyping (low-expressing genotype [deficiency] defined as homozygosity for exon 1 mutations [YO/YO] or compound heterozygosity [XA/YO]; YA/YO and XA/XA genotypes were defined as intermediate-expressing with all other genotypes defined as high-expressing) and serum measurements (deficiency defined with two parameters: <500 ng/mL or <200 ng/mL). We assessed rates of exacerbation, chronic bacterial colonisation, and lung function during 4 years of follow-up. FINDINGS: We included 470 patients with bronchiectasis and 414 controls. MBL genotype frequencies and MBL serum concentrations did not differ between patients and controls. 55 (12%) patients with bronchiectasis had low-expressing genotypes. These patients had a mean of 2·7 exacerbations per year (SD 1·8), compared with 1·9 per year (1·2) for 135 patients with intermediate-expressing genotypes and 1·9 per year (1·3) for 280 patients with high-expressing genotypes (p<0·0001). Chronic colonisation with bacteria was most frequent in patients with low-expressing genotypes (47 [85%] patients vs 82 [61%] patients with intermediate-expressing genotypes and 183 [65%] patients with high-expressing genotypes; p=0·0041); especially P aeruginosa colonisation (19 [35%] patients vs 13 [10%] patients and 36 [13%] patients; p<0·0001). Patients with low-expressing genotypes were more likely to be admitted to hospital for severe exacerbations during follow-up (27 [49%] patients vs 42 [31%] patients and 87 [31%] patients; p=0·032). Patients with low-expressing genotypes also had increased scores for radiological severity and worse quality of life compared with the other two groups. MBL serum deficiency (<200 ng/mL) was associated with increased exacerbations, hospital admissions, and radiological severity. When <500 ng/mL was used as the definition of deficiency, the associations with exacerbation frequency and radiological severity were no longer significant. INTERPRETATION: MBL might be an important modifier of disease severity in non-CF bronchiectasis. FUNDING: UK Medical Research Council, UK Chief Scientists Office.

Short- and long-term antibiotic treatment reduces airway and systemic inflammation in non-cystic fibrosis bronchiectasis.

RATIONALE: The vicious cycle hypothesis of bronchiectasis argues that bacterial colonization leads to airway inflammation and progressive lung damage. The logical extension of this hypothesis is that acute or chronic antibiotic therapy should improve airway inflammation and clinical outcome. There are little data to support this hypothesis in patients with non-cystic fibrosis (CF) bronchiectasis. OBJECTIVES: To determine whether acute or chronic antibiotic therapy improves airway inflammation and clinical outcome in non-CF bronchiectasis. METHODS: The relationship between bacterial load and airway and systemic inflammation was investigated in 385 stable patients, 15 stable patients treated with intravenous antibiotics, and 34 patients with an exacerbation of bronchiectasis treated with intravenous antibiotics. Long-term antibiotic therapy was investigated using samples from a 12-month controlled trial of nebulized gentamicin. MEASUREMENTS AND MAIN RESULTS: In stable patients, there was a direct relationship between airway bacterial load and markers of airway inflammation (P < 0.0001 for all analyses). High bacterial loads were associated with higher serum intercellular adhesion molecule-1, E-selectin, and vascular cell adhesion molecule-1 (P < 0.05 above bacterial load ≥1 × 10(7) cfu/ml). In stable patients, there was a direct relationship between bacterial load and the risk of subsequent exacerbations (odds ratio, 1.20; 95% confidence interval, 1.11-1.29; P < 0.0001) and severe exacerbations (odds ratio, 1.11; 95% confidence interval, 1.01-1.21; P = 0.02). Short- and long-term antibiotic treatments were associated with reductions in bacterial load, airways, and systemic inflammation. CONCLUSIONS: High airway bacterial loads in non-CF bronchiectasis are associated with airway and systemic inflammation and a greater risk of exacerbations. Short- and long-term antibiotic therapy reduce markers of airways and systemic inflammation.

Evaluating success of therapy for bronchiectasis: what end points to use?

Long-term treatment goals of bronchiectasis frequently include limiting the bacterial burden and inflammatory insult in the airways with the aim of improving symptoms, reducing exacerbation frequency and severity, and improving health-related quality-of-life. However, few clinical or laboratory markers specifically validated for bronchiectasis exist, and how best to assess the disease and its response to treatment is poorly understood. Pertinent, reliable markers are urgently needed to facilitate effective treatment of bronchiectasis and to ensure ongoing development of future therapies. This article explores the utility of potential end points in evaluating therapies used in the long-term management of stable bronchiectasis.