[Small airway diseases and immune deficiency]

INTRODUCTION

Innate or acquired immune deficiency may show respiratory manifestations, often characterized by small airway involvement. The purpose of this article is to provide an overview of small airway disease across the major causes of immune deficiency.

BACKGROUND

In patients with common variable immune deficiency, recurrent lower airway infections may lead to bronchiolitis and bronchiectasis. Follicular and/or granulomatous bronchiolitis of unknown origin may also occur. Bronchiolitis obliterans is the leading cause of death after the first year in patients with lung transplantation. Bronchiolitis obliterans also occurs in patients with allogeneic haematopoietic stem cell transplantation, especially in the context of systemic graft-versus-host disease.

VIEWPOINT AND CONCLUSION

Small airway diseases have different clinical expression and pathophysiology across various causes of immune deficiency. A better understanding of small airways disease pathogenesis in these settings may lead to the development of novel targeted therapies.

Prevalence and reversibility of lung hyperinflation in adult asthmatics with poorly controlled disease or significant dyspnea

BACKGROUND

In asthma, inflammation affects both the proximal and distal airways and may induce significant hyperinflation (HI). This study sought to evaluate the prevalence of HI in asthmatic patients with poorly controlled disease and/or dyspnea.

METHODS

Poor asthma control was defined by an Asthma Control Test (ACT) score <20 (n = 287), and dyspnea was defined as a modified Medical Research Council score ≥1 (n = 18). HI was defined as either a residual volume/total lung capacity (RV/TLC) above the upper limit of normal (RV-HI) or a functional residual capacity (FRC) >120% predicted (FRC-HI). HI reversibility after administration of salbutamol (400 μg) was defined as a decrease in RV >20% or a reduction in FRC >10%. Changes in dyspnea and chest tightness were evaluated on a visual analogue scale.

RESULTS

Both RV-HI and FRC-HI were observed in 48% of the 305 patients (mean ± SD age: 49 ± 17; FEV1 : 75 ± 18% predicted) included in the study. The prevalence of HI was higher in patients with a FEV1 <60% predicted (93% for RV-HI and 71% for FRC-HI, vs 21% and 41% in patients with a FEV1 > 80%). In patients with HI, the ACT score was lower and chest tightness higher. HI reversibility was obtained in 38% of the asthmatics with FRC-HI and 29% of the asthmatics with RV-HI, whereas FEV1 reversibility was obtained in half of these patients.

CONCLUSIONS

HI is highly prevalent in poorly controlled asthmatics suggesting small airway dysfunction and may represent an additional criteria for evaluating responsiveness to bronchodilators.

[Prevention of COPD exacerbation: a fundamental challenge]

INTRODUCTION

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are a cause of suffering for patients and a burden for healthcare systems and society. Their prevention represents individual and collective challenge. The present article is based on the work of a group of experts who met on 5th and 6th May 2011 and seeks to highlight the importance of AECOPD.

STATE OF THE ART

In the absence of easily quantifiable criteria, the definition of AECOPD varies in the literature, making identification difficult and affecting interpretation of study results. Exacerbations increase mortality and risk of cardiovascular disease. They also increase the risk of developing further exacerbations, accelerate the decline in lung function and contribute to reduction in muscle mass. By limiting physical activity and affecting mental state (anxiety, depression), AECOPD are disabling and impair quality of life. They increase work absenteeism and are responsible for about 60% of the global cost of COPD.

PERSPECTIVES

Earlier identification with simple criteria, possibly associated to patient phenotyping, could be helpful in preventing hospitalization.

CONCLUSIONS

Given their immediate and delayed impact, AECOPD should not be trivialized or neglected. Their prevention is a fundamental issue.

[Lung volume reduction surgery for emphysema and bullous pulmonary emphysema]

The improvement of respiratory symptoms for emphysematous patients by surgery is a concept that has evolved over time. Initially used for giant bullae, this surgery was then applied to patients with diffuse microbullous emphysema. The physiological and pathological concepts underlying these surgical procedures are the same in both cases: improve respiratory performance by reducing the high intrapleural pressure. The functional benefit of lung volume reduction surgery (LVRS) in the severe diffuse emphysema has been validated by the National Emphysema Treatment Trial (NETT) and the later studies which allowed to identify prognostic factors. The quality of the clinical, morphological and functional data made it possible to develop recommendations now widely used in current practice. Surgery for giant bullae occurring on little or moderately emphysematous lung is often a simpler approach but also requires specialised support to optimize its results.

[Eosinophilic pleural effusion related to taking valproic acid]

Eosinophilic pleural effusions have multiple aetiologies. We report on the case of a 40-year-old man who experienced an eosinophilic pleural effusion with blood hypereosinophilia that occurred nine weeks after a treatment with valproic acid was introduced. Usual aetiologies of eosinophilic pleural effusion were excluded. Once valproic acid was discontinued, both pleural effusion and blood eosinophilia decreased rapidly. The persistence of a residual pleural effusion required the introduction of oral corticosteroids, which resulted in the effusion disappearing completely and rapidly. Valproic acid is a rare cause of eosinophilic pleural effusion. The effusion usually regresses when treatment is discontinued but short-term oral corticotherapy may be necessary in order to heal the patient.

Update on the roles of distal airways in asthma

The present review is the summary of an expert workshop that took place in Vence (France) in 2007 on the role of distal airways in asthma. The evidence showing inflammation and remodelling in distal airways, and their possible involvement in asthma control and natural history, was reviewed. The usefulness and limitations of various techniques used for assessing distal airways were also evaluated, including pulmonary function tests and imaging. Finally, the available data studying the benefit of treatment better targeting distal airways in asthma was examined. It was concluded that both proximal and distal airways were involved in asthma and that distal airways were the major determinant of airflow obstruction. Inflammation in distal airways appeared more intense in severe and uncontrolled asthma. Distal airways were poorly attained by conventional aerosol of asthma medications owing to their granulometry, being composed of 3-5&emsp14;μm particles. Both proximal and distal airways might be targeted either by delivering medications systemically or by aerosol of extra-fine particles. Extra-fine aerosols of long-acting β-agonists, inhaled corticosteroids or inhaled corticosteroid/long-acting β-agonist combinations have been shown in short-term studies to be not inferior to non-extra-fine aerosols of comparators. However, available studies have not yet demonstrated that extra-fine inhaled medications offer increased benefit compared with usual aerosols in asthmatic patients.

[Treatments targeting distal airways in asthma: update on clinical studies]

Two strategies are possible for targeting distal airways in asthma. The first one is systemic, with the delivery of medications either orally or intravenously. Montelukast is the only oral drug that has demonstrated its efficacy on distal airways by reducing lung hyperinflation. The second possible strategy is to deliver inhaled medications using ultrafine particles. Studies performed with formoterol-HFA solution (Formoair Modulite), the only available long-acting beta2 agonist with ultrafine particles have shown a non-inferior bronchodilator effect and a good tolerance as compared to inhaled long acting beta2 agonists with non-ultrafine particles. Studies performed with BDP-HFA alone (QVAR) or combined BDP-HFA/formoterol (Fostair) with ultrafine particles have mostly demonstrated their clinical non- inferiority on bronchodilation, quality of life, and symptoms in asthmatic subjects as compared to non-ultrafine inhaled medications. With the exception of a few studies, most publications have been performed in a limited number of patients and for only short durations. The available studies have not yet demonstrated a long-term benefit in terms of additional clinical efficacy of these ultrafine inhaled medications on symptoms, control and exacerbations of asthma.

Non-classic cystic fibrosis associated with D1152H CFTR mutation

BACKGROUND

Limited knowledge exists on phenotypes associated with the D1152H cystic fibrosis transmembrane conductance regulator (CFTR) mutation.

METHODS

Subjects with a D1152H allele in trans with another CFTR mutation were identified using the French Cystic Fibrosis Registry. Phenotypic characteristics were compared with those of pancreatic insufficient (PI) and pancreatic sufficient (PS) cystic fibrosis (CF) subjects in the Registry (CF cohort).

RESULTS

Forty-two subjects with D1152H alleles were identified. Features leading to diagnosis included chronic sinopulmonary disease (n = 25), congenital absence of the vas deferens (n = 11), systematic neonatal screening (n = 4), and genetic counseling (n = 2). Median age at diagnosis was 33 [interquartile range (IQR, 24-41)] years in D1152H subjects. Median sweat chloride concentrations were 43.5 (39-63) mmol/l in D1152H subjects and were markedly lower than in PI and PS CF subjects (p < 0.05). Bronchiectasis was present in 67% of D1152H subjects, but Pseudomonas aeruginosa colonization and pancreatic insufficiency were present in <30% of subjects. Estimated rates of decline in forced expiratory volume in 1 s (FEV(1)) were lower in D1152H subjects vs PI CF subjects (p < 0.05). None of the D1152H subjects identified since 1999 had died or required lung transplantation.

CONCLUSIONS

When present in trans with a CF-causing mutation, D1152H causes significant pulmonary disease, but all subjects had prolonged survival.

Clinical characteristics and prognostic factors of pulmonary MALT lymphoma

Mucosa-associated lymphoid tissue-derived (MALT) lymphoma, a low grade B-cell extranodal lymphoma, is the most frequent subset of primary pulmonary lymphoma. Our objective was to evaluate the initial extent of disease and to analyse the characteristics and long-term outcome of these patients. All chest and pathological departments of teaching hospitals in Paris were contacted in order to identify patients with a histological diagnosis of primary pulmonary lymphoma of the MALT subtype. 63 cases were identified. The median age was 60 yrs. 36% of cases had no symptoms at diagnosis. 46% of patients had at least one extrapulmonary location of lymphoma. The estimated 5- and 10-yr overall survival rates were 90% and 72%, respectively. Only two of the nine observed deaths were related to lymphoma. Age and performance status were the only two adverse prognostic factors for survival. Extrapulmonary location of lymphoma was not a prognostic factor for overall survival or for progression-free survival. Treatment with cyclophosphamide or anthracycline was associated with shorter progression-free survival, when compared with chlorambucil. The survival data confirm the indolent nature of pulmonary MALT lymphoma. Better progression-free survival was observed with chlorambucil when compared with cyclophosphamide or anthracycline.

[The diagnosis of cystic fibrosis in adults: lessons from a family story]

INTRODUCTION

Cystic fibrosis is usually diagnosed during the first years of life. Diagnosis may be achieved in adults with milder forms of the disease at any age.

CASE REPORTS

We report the diagnosis of cystic fibrosis in three adults within the same family. A 39 yr old man, was diagnosed with congenital absence of the vas deferens; the diagnosis of cystic fibrosis was achieved based on a positive chloride sweat test and the identification of two mutations in the CFTR gene. His mother experienced repeated bronchial infections that began when she was 12 years old. The diagnosis of cystic fibrosis was considered at the age of 74 yr after her son was diagnosed with this disease. Sweat test showed normal chloride concentrations and cystic fibrosis was suspected based on elevated basal transepithelial nasal potential difference. Genetic testing for the 33 most frequent mutations in the CFTR gene showed only one mutation. A second rare mutation was identified by complete sequencing of the CFTR gene, confirming the diagnosis of cystic fibrosis. A third case of pauci-symptomatic cystic fibrosis was diagnosed in a brother of the index case.

CONCLUSION

These observations illustrate the challenge of diagnosing milder forms of cystic fibrosis in adult subjects. The recognition of this diagnosis may lead to improvement in patient's care and to genetic counselling.