Cough and wheeze events are temporally associated with increased pain in individuals with sickle cell disease without asthma

[Lung manifestations of sickle-cell disease]

Sickle-cell disease is an autosomal recessive genetic disorder of hemoglobin that causes systemic damage. Hypoxia is the main actor of sickle-cell disease. It initiates acutely the pathogenic cascade leading to tissue damages that in turn induce chronic hypoxia. Lung lesions represent the major risk of morbidity and mortality. Management of sickle-cell disease requires a tight collaboration between hematologists, intensivists and chest physicians. Recurrent episodes of thrombosis and hemolysis characterize the disease. New therapeutic protocols, associating hydroxyurea, transfusion program and stem cell transplantation in severe cases allow a prolonged survival until the fifth decade. However, recurrent pain, crisis, frequent hospital admissions due to infection, anemia or acute chest syndrome and chronic complications leading to organ deficiencies degrade the patients' quality of life. In low-income countries where the majority of sickle-cell patients are living, the disease is still associated with a high mortality in childhood. This paper focuses on acute chest syndrome and chronic lung manifestations.

SNAP: Supportive noninvasive ventilation for acute chest syndrome prevention in children with sickle cell disease

BACKGROUND

Acute chest syndrome (ACS) is a leading cause of morbidity and mortality among children with sickle cell disease (SCD). Preventing hypoxemia by optimizing lung aeration during sleep remains a challenge.

OBJECTIVES

To explore safety, feasibility, and tolerability of noninvasive, bi-level positive airway pressure ventilation (BiPAP) as preventative, supportive care for hospitalized, medically stable children with SCD on a general pediatric inpatient unit.

METHODS

Retrospective chart review of patients ≤22 years of age with SCD admitted to the general pediatric inpatient unit from February 1, 2017 to March 1, 2020 for whom BiPAP was recommended as supportive care. Hospitalizations were excluded if patients were admitted to the pediatric intensive care unit (PICU), required BiPAP for respiratory failure, or used BiPAP at home for obstructive sleep apnea.

RESULTS

Twenty-three patients had 53 hospitalizations in which BiPAP was recommended. Fifty-two (98%) hospitalizations included acute SCD pain. Indications for BiPAP included prior ACS (94%), chest or back pain (79%), and/or oxygen desaturation (66%). On 17 occasions, patients already had mild to moderate ACS but were stable when BiPAP was recommended. BiPAP was used successfully during 75% of hospitalizations for a median of two nights. There were no adverse effects associated with BiPAP. PICU transfer for respiratory support occurred during three hospitalizations. In 26 hospitalizations of children at risk for ACS who tolerated BiPAP, 23 (88%) did not develop ACS.

CONCLUSIONS

BiPAP is safe, feasible, and well tolerated as supportive care for hospitalized children with SCD. Next steps include an intervention trial to further assess the efficacy of BiPAP on ACS prevention.

The Wide-Ranging Spectrum of Cough-Induced Complications and Patient Harm

Cough is one of the most common complaints encountered in every setting; however, complications associated with coughing have received relatively little attention. An exhaustive systematic review of the English literature revealed an exceedingly large and varied spectrum of cough-induced complications affecting many systems, including upper airways, chest wall and thorax, abdominal wall, heart and aorta, central nervous system, eye, gastrointestinal tract, urogenital system, and emotional and psychological harm. Prospective studies and prevalence data are conspicuously missing. Reported cough-induced pathology ranges from rare (the majority) to common and from trivial (eg, lightheadedness, subconjunctival hemorrhage) to severe and life-threatening (eg, cervical artery dissection, rupture of a normal spleen). Other seemingly benign entities may mask a serious underlying pathology (eg, cough headache, cough syncope). A substantial proportion of patients experience anxiety and insomnia, and their quality of life is affected. Thus, the wide spectrum of cough-induced pathology need to be recognized and considered in patients complaining of cough. Suppression of cough must not be neglected in patients at risk, and areas of uncertainty need to be clarified by future prospective studies.

Effects of air pollution on moderate and severe asthma exacerbations

Background: Few studies have evaluated the impact of air pollution levels on the severity of exacerbations. Thus, we compared the relative risks posed by air pollutant levels on moderate and severe exacerbations.Methods: Exacerbation episodes of 618 from 143 adult asthmatics were retrospectively collected between 2005 and 2015 in a tertiary hospital of Korea. Air pollution GPS data for the location closest to each patient's home were obtained from the national ambient monitoring station. The relative impacts of air pollutants on asthma exacerbations were evaluated via a time-trend controlled symmetrical, bidirectional, case-crossover design using conditional logistic regression models on the day of the exacerbation (T-0) and up to 3 days before the exacerbation (T-1-T-3).Results: Overall asthma exacerbation were associated with O₃ levels in summer and winter (OR: 1.012[1.003-1.02] and 1.009[1.003-1.016]), SO₂ levels in spring and summer (OR: 1.009[1-1.018] and 1.02[1.006-1.035]) and NO₂ levels in winter (OR: 1.007[1.003-1.011]). Analyses of the temporal relationship between O₃ concentrations and exacerbations demonstrated that 63.2% of episodes in the summer occurred when the O₃ concentrations on T-1 were significantly higher than those on control days, while 51% of exacerbation episodes in the winter occurred. Severe and moderate exacerbations were similarly associated with O₃ levels in winter (OR: 1.012 [1.003-1.02] vs. 1.01 [0.999-1.021], p > 0.05) and in summer (OR: 1.006 [1.002-1.009] vs. 1.009 [1.003-1.016], p > 0.05).Conclusions: Asthma exacerbations may be associated with the seasonal elevation of O₃, SO₂ and NO₂ levels in summer and winter with the similar relative risk between moderate and severe exacerbations.

House Dust Mite-Induced Allergic Lung Inflammation Is Not Exacerbated in Sickle Cell Disease Mice

AIM

Asthma appears to be a common comorbid condition in children with sickle cell disease (SCD), and such individuals may be at a higher risk for increased morbidity and mortality. However, several reports have indicated that asthma severity is not particularly high in those with SCD, and airway hyperreactivity and wheeze may be independently associated with SCD. In SCD mice, exacerbated allergic airway disease (AAD) has been observed in response to the model antigen ovalbumin (OVA). We sought to determine if allergic lung inflammation is also exacerbated in SCD mice when they are exposed to the human allergen, house dust mite (HDM).

METHODS AND RESULTS

Eosinophil counts in bronchoalveolar lavage fluid were determined by cytocentrifugation and increased in both wild-type (WT) and SCD mice after acute exposure to a high dose (25 µg) of HDM, which then decreased in chronically exposed mice. WT mice exposed to a low dose of HDM (1 µg) followed the same pattern of eosinophil flux, but SCD mice did not induce much eosinophilia after acute exposure to HDM. As was observed in previous studies, lung lesions similarly increased in severity in both WT and SCD mice after acute exposure to HDM, which remained elevated after chronic exposure. Furthermore, serum HDM-specific IgE titers similarly increased and selected serum cytokines were similar in both WT and SCD mice.

CONCLUSION

These results contrast with previous reports of exacerbated AAD in SCD mice exposed to OVA and support the alternative hypothesis that asthmatic responses are normal in those with SCD.

Inhaled steroids associated with decreased macrophage markers in nonasthmatic individuals with sickle cell disease in a randomized trial

Inhaled mometasone was shown to improve pain scores and decrease soluble vascular cell adhesion molecule (sVCAM) concentration in a randomized controlled trial of nonasthmatic patients with sickle cell disease. We sought to explore potential changes in systemic inflammation as a mechanism underlying this effect. Serum samples from 41 trial participants (15 placebo- and 26 mometasone-treated) were analyzed using a 92 inflammatory marker panel at baseline and after 8 weeks of mometasone therapy. Individual marker analysis and correlation analysis were conducted. Adjusted for age, the mometasone-treated group decreased the concentration of CXCL9, CXCL11, CD40, IL-10, and IL-18 relative to placebo-treated participants. Hierarchical clustering and correlation analysis identified additional evidence for a decrease in cytokines linking to macrophage signaling and migration. There was no statistically significant change in markers of asthma and allergy, indicating that the improvement was unlikely mediated by modulation of occult reactive airway disease. This analysis of inflammatory markers suggests that decrease in macrophage activity may be involved in the mediation of the clinical benefit seen with use of inhaled mometasone in nonasthmatic patients with sickle cell disease.Trial registration: clinicaltrials.gov identifier: NCT02061202.

Inhaled steroids reduce pain and sVCAM levels in individuals with sickle cell disease: A triple-blind, randomized trial

Clinical and preclinical data demonstrate that altered pulmonary physiology (including increased inflammation, increased blood flow, airway resistance, and hyper-reactivity) is an intrinsic component of Sickle Cell Disease (SCD) and may contribute to excess SCD morbidity and mortality. Inhaled corticosteroids (ICS), a safe and effective therapy for pulmonary inflammation in asthma, may ameliorate the altered pulmonary physiologic milieu in SCD. With this single-center, longitudinal, randomized, triple-blind, placebo controlled trial we studied the efficacy and feasibility of ICS in 54 nonasthmatic individuals with SCD. Participants received once daily mometasone furoate 220 mcg dry powder inhalation or placebo for 16 weeks. The primary outcome was feasibility (the number who complete the trial divided by the total number enrolled) with prespecified efficacy outcomes including daily pain score over time (patient reported) and change in soluble vascular cell adhesion molecule (sVCAM) levels between entry and 8-weeks. For the primary outcome of feasibility, the result was 96% (52 of 54, 95% CI 87%-99%) for the intent-to-treat analysis and 83% (45 of 54, 95% CI 71%-91%) for the per-protocol analysis. The adjusted treatment effect of mometasone was a reduction in daily pain score of 1.42 points (95%CI 0.61-2.21, P = 0.001). Mometasone was associated with a reduction in sVCAM levels of 526.94 ng/mL more than placebo (95% CI 50.66-1003.23, P = 0.03). These results support further study of ICS in SCD including multicenter trials and longer durations of treatment. www.clinicaltrials.gov (NCT02061202).

Sickle cell disease: wheeze or asthma?

Sickle cell disease (SCD) is the most common life-limiting genetic disease among African Americans, affecting more than 100,000 people in the United States. Respiratory disorders in patients with sickle cell disease have been associated with increased morbidity and mortality. Associations between asthma and pain, acute chest syndrome (ACS), and even death have long been reported. More recently wheezing, even in the absence of an asthma diagnosis, has gained attention as a possible marker of SCD severity. Several challenges exist with regards to making the diagnosis of asthma in patients with SCD, including the high prevalence of wheezing, evidence of airway obstruction on pulmonary function testing, and/or airway hyperresponsiveness among patients with SCD. These features often occur in isolation, in the absence of other clinical criteria necessary for an asthma diagnosis. In this review we will summarize: 1) Our current understanding of the epidemiology of asthma, wheezing, airway obstruction, and airway responsiveness among patients with SCD; 2) The evidence supporting associations with SCD morbidity; 3) Our understanding of the pathophysiology of airway inflammation in SCD; 4) Current approaches to diagnosis and management of asthma in SCD; and 5) Future directions.

Environmental determinants of severity in sickle cell disease

Sickle cell disease causes acute and chronic illness, and median life expectancy is reduced by at least 30 years in all countries, with greater reductions in low-income countries. There is a wide spectrum of severity, with some patients having no symptoms and others suffering frequent, life-changing complications. Much of this variability is unexplained, despite increasingly sophisticated genetic studies. Environmental factors, including climate, air quality, socio-economics, exercise and infection, are likely to be important, as demonstrated by the stark differences in outcomes between patients in Africa and USA/Europe. The effects of weather vary with geography, although most studies show that exposure to cold or wind increases hospital attendance with acute pain. Most of the different air pollutants are closely intercorrelated, and increasing overall levels seem to correlate with increased hospital attendance, although higher concentrations of atmospheric carbon monoxide may offer some benefit for patients with sickle cell disease. Exercise causes some adverse physiological changes, although this may be off-set by improvements in cardiovascular health. Most sickle cell disease patients live in low-income countries and socioeconomic factors are undoubtedly important, but little studied beyond documenting that sickle cell disease is associated with decreases in some measures of social status. Infections cause many of the differences in outcomes seen across the world, but again these effects are relatively poorly understood. All the above factors are likely to account for much of the pathology and variability of sickle cell disease, and large prospective studies are needed to understand these effects better.