Véronique Godding

Lung mucosal immunity: immunoglobulin‐A revisited

Mucosal defence mechanisms are critical in preventing colonization of the respiratory tract by pathogens and penetration of antigens through the epithelial barrier. Recent research has now illustrated the active contribution of the respiratory epithelium to the exclusion of microbes and particles, but also to the control of the inflammatory and immune responses in the airways and in the alveoli. Epithelial cells also mediate the active transport of polymeric immunoglobulin-A from the lamina propria to the airway lumen through the polymeric immunoglobulin receptor. The role of IgA in the defence of mucosal surfaces has now expanded from a limited role of scavenger of exogenous material to a broader protective function with potential applications in immunotherapy. In addition, the recent identification of receptors for IgA on the surface of blood leukocytes and alveolar macrophages provides an additional mechanism of interaction between the cellular and humoral immune systems at the level of the respiratory tract.We read through the Review by PILETTE et al. [1] with extreme interest and would like to add a contribution to the subject of airways immunity in chronic obstructive pulmonary disease (COPD). For a long time, we have witnessed, at least in Italy, the predominance of the notion that all COPD patients have a certain degree of immune deficiency as a basic pathogenetic mechanism, since they experience recurrent bronchitis exacerbations. Scientific evidence of true general or local immune defects in COPD is, in our opinion, inconclusive, although we fully agree on the point made by the authors that all the studies in the literature share methodological limitations, both in sampling and analysis techniques and in selection of patients. In our experience, different immune components can appear either similar to controls or increased (as a likely consequence of repeated stimulation by exacerbations or chronic bacterial colonization of the airways), or decreased in a specific group of COPD patients. Indeed, we recently reported decreased numbers of CD3 and CD8 lymphocytes in the bronchial biopsies of severe COPD patients, associated with an increase of neutrophils and macrophages [2]. With particular regard to immunoglobulin (Ig)-A, we found only an insignificant increase in patients with mild COPD who had never smoked [3], and a high increase in severe but clinically stable COPD patients with chronic tracheostomy and a high level of bacterial colonization [4]. The experience with tracheostomized COPD patients is very interesting because they provide a model of bacteria/host interaction in which the role of immunity can be evaluated prospectively. The presence of high levels of IgA in bronchial aspirates could, in part, justify the relatively low rate of lower respiratory tract infections in these patients after discharge from hospital [5]. We appreciated the long and accurate list of defence mechanisms in the respiratory tract reported by the authors, which clearly shows that specific immune functions are only a part of the airways protection system. Indirect proof that immunoglobulins are only a part, albeit an important part, of mucosal immunity, comes from studies on the stimulation of mucosaassociated lymphoid tissues with oral vaccines or bacterial extracts, which have been demonstrated to reduce the impact of bronchitis exacerbations, at least in mild-to-moderate chronic obstructive pulmonary disease [6]. The mechanisms of action were reflected in an increase of immunoglobulin-A in the airways9 fluids, but more solid evidence, from a biological point of view, was the activation of alveolar macrophages [7]. In our opinion, the potential of oral bacterial extracts to stimulate immunoglobulin-A production in the airways should be further investigated. In conclusion, we would once again like to stress that the impairment of defence systems in the airways is not simply a question of specific immunity, and that a clinically relevant imbalance in chronic obstructive pulmonary disease must be evaluated within a complex defence network concept, rather than in a simple cause/effect perspective.

Primary ciliary dyskinesia: critical evaluation of clinical symptoms and diagnosis in patients with normal and abnormal ultrastructure

BackgroundPrimary ciliary dyskinesia (PCD) is a rare disorder with variable disease progression. To date, mutations in more than 20 different genes have been found. At present, PCD subtypes are described according to the ultrastructural defect on transmission electron microscopy (TEM) of the motile cilia. PCD with normal ultrastructure (NU) is rarely reported because it requires additional testing. Biallelic mutations in DNAH11 have been described as one cause of PCD with NU.The aim of our study was to describe the clinical characteristics of a large population of patients with PCD, in relation to the ultrastructural defect. Additionally, we aimed to demonstrate the need for biopsy and cell culture to reliably diagnose PCD, especially the NU subtype.MethodsWe retrospectively analyzed data from 206 patients with PCD. We compared the clinical characteristics, lung function, microbiology and imaging results of 68 patients with PCD and NU to those of 90 patients with dynein deficiencies and 41 patients with central pair abnormalities. In addition, we aimed to demonstrate the robustness of the diagnosis of the NU subtype in cell culture by data from genetic analysis.ResultsPCD with NU comprised 33% (68/206) of all patients with PCD. Compared to other subtypes, patients with PCD and NU had a similar frequency of upper and lower respiratory tract problems, as well as similar lung function and imaging. With the currently widely applied approach, without cell culture, the diagnosis would have been missed in 16% (11/68) of patients with NU. Genetic analysis was performed in 29/68 patients with PCD and NU, and biallelic mutations were found in 79% (23/29) of tested patients.ConclusionsWe reported on the clinical characteristics of a large population of patients with PCD and NU. We have shown that systematic performance of biopsy and cell culture increases sensitivity to detect PCD, especially the subtype with NU.PCD with NU has similar clinical characteristics as other PCD types and requires biopsy plus ciliogenesis in culture for optimal diagnostic yield.

Does in utero exposure to heavy maternal smoking induce nicotine withdrawal symptoms in neonates

Maternal drug use during pregnancy is associated with fetal passive addiction and neonatal withdrawal syndrome. Cigarette smoking—highly prevalent during pregnancy—is associated with addiction and withdrawal syndrome in adults. We conducted a prospective, two-group parallel study on 17 consecutive newborns of heavy-smoking mothers and 16 newborns of nonsmoking, unexposed mothers (controls). Neurologic examinations were repeated at days 1, 2, and 5. Finnegan withdrawal score was assessed every 3 h during their first 4 d. Newborns of smoking mothers had significant levels of cotinine in the cord blood (85.8 ± 3.4 ng/mL), whereas none of the controls had detectable levels. Similar findings were observed with urinary cotinine concentrations in the newborns (483.1 ± 2.5 μg/g creatinine versus 43.6 ± 1.5 μg/g creatinine; p = 0.0001). Neurologic scores were significantly lower in newborns of smokers than in control infants at days 1 (22.3 ± 2.3 versus 26.5 ± 1.1; p = 0.0001), 2 (22.4 ± 3.3 versus 26.3 ± 1.6; p = 0.0002), and 5 (24.3 ± 2.1 versus 26.5 ± 1.5; p = 0.002). Neurologic scores improved significantly from day 1 to 5 in newborns of smokers (p = 0.05), reaching values closer to control infants. Withdrawal scores were higher in newborns of smokers than in control infants at days 1 (4.5 ± 1.1 versus 3.2 ± 1.4; p = 0.05), 2 (4.7 ± 1.7 versus 3.1 ± 1.1; p = 0.002), and 4 (4.7 ± 2.1 versus 2.9 ± 1.4; p = 0.007). Significant correlations were observed between markers of nicotine exposure and neurologic-and withdrawal scores. We conclude that withdrawal symptoms occur in newborns exposed to heavy maternal smoking during pregnancy.

Early referral to cystic fibrosis specialist centre impacts on respiratory outcome.

BACKGROUND Published studies concerning the impact of specialist care on lung disease in cystic fibrosis remain limited and most are either biased due to comparison with historical controls and/or underpowered. METHODS In this retrospective multicentric study, data from all CF children fulfilling the following criteria were collected: 1) Age 6-<18 at the end of 2003; 2) diagnosis before 8 y; 3) follow-up in an accredited CF Belgian centre; 4) at least 1 spirometry and respiratory culture available for 2003. Group A included children referred > or =2 years after the diagnosis. Patients from Group A were then matched with a single early referred patient on the basis of 2 criteria: same centre, as closest age as possible (Group B). RESULTS Data from 217 children were collected (Group A: 67/217). Late referred patients had a lower FEV(1) (77.2%+/-22.4 vs 86.7% pred.+/-19.4, p=0.01) and a higher prevalence of Pseudomonas aeruginosa (38.6 vs 17.5%, p<0.05). CONCLUSION In this population of CF children, a delay of 6.1 y (vs 0.1 y) between diagnosis and referral to a specialist clinic resulted in poorer respiratory outcome at age 13.

Secretory component production by human bronchial epithelial cells is upregulated by interferon gamma.

Secretory immunoglobulin A (S-IgA) participates in the first noninflammatory line of defence of the respiratory tract. S-IgA consists of dimeric IgA (dIgA) produced by plasma cells and secretory component (SC) produced by epithelial cells. This study compared SC production by primary cultures of human bronchial epithelial cells (HBEC) and by respiratory epithelial cell lines. Among the cell lines, A549 did not produce detectable SC, 16HBE produced very low levels of SC, while CALU-3 produced significant levels of SC. HBEC produced SC in nonpolarized and polarized primary cultures, where it was secreted apically. Polarized HBEC transcytosed radiolabelled and cold dIgA, resulting in the presence of S-IgA in their apical media. SC production and IgA transcytosis by polarized HBEC were upregulated by interferon-gamma (IFN-gamma) after 48 h. By reverse transcription-polymerase chain reaction, no SC messenger ribonucleic acid (mRNA) was detected in A549 and 16HBE, while SC mRNA in CALU-3 was comparable to that of HBEC incubated for 48 h with IFN-gamma. By immunocytochemistry, HBEC expressed SC immunostaining and its intensity increased after 48 h with IFN-gamma. It is concluded that human bronchial epithelial cells produce secretory component and transcytose dimeric immunoglobulin A in vitro. These processes were apically polarized and upregulated by interferon-gamma. Among the cell lines studied, only CALU-3 expressed secretory component-messenger ribonucleic acid and produced detectable secretory component.

Omalizumab for exacerbations of allergic bronchopulmonary aspergillosis in patients with cystic fibrosis

Anti-IgE therapy was proposed to two teenagers with cystic fibrosis (CF) with allergic bronchopulmonary aspergillosis (ABPA) exacerbation, reluctant to a further course of oral steroids. Both patients experienced ABPA exacerbations within the past 3 years, requiring oral steroid bursts. Clinical, laboratory and radiographic features were consistent with ABPA exacerbations (representing at the time of evaluation the fourth and third episodes for patient 1 and 2, respectively). Total serum IgE was very high, >1000 kU/litre in both cases. Treatment consisting of subcutaneous injections of 375 mg anti-IgE (omalizumab) twice monthly was successful in rapidly improving respiratory symptoms and lung function. Based on clinical and functional improvement, interval between injections was progressively increased and treatment could be withdrawn after 11 injections, without recurrence at 20 weeks of follow-up after withdrawal.

Qualité de la prise en charge de l'enfant admis en salle d'urgence polyvalente

AIM: By a prospective study, authors tried to analyse the quality of management of the pediatric patient admitted in the emergency department. POPULATION AND METHODS: One hundred admission files were prospectively analysed for characteristics of age (mean age: 70 months), effectiveness of measurement of physiological parameters, evaluation of appropriateness of nursing management according to recorded parameters, length of stay in the emergency department according to the need for hospitalization, blood tests, X-rays and the seniority of the attending medical staff. RESULTS: Parameters were not, or only incompletely, recorded in 65 files. . Although all were recorded in the remaining 35 files, subsequent management was inadequate in seven cases. Mean length of stay in the emergency department was 116 minutes, influenced by the need for hospitalization (145 minutes compared to 102 minutes for the non-hospitalized children), timing of admission (mean: 125 minutes from 8 am to 6 pm, compared to 94 minutes from 6 pm to 8 am), need for blood tests, X-rays or both (mean: 122, 107 and 170 minutes respectively, compared to 55 minutes when no complementary exam was asked) and seniority of attending medical staff (mean: 65 minutes for permanent staff compared to 116 minutes for fellows). CONCLUSIONS: Measurement of physiological parameters must be standard practise in the management of pediatric patients admitted to the emergency department and must lead to appropriate management without undue delay. In order to reach this goal, emergency departments should be more adequately staffed with nurses and senior doctors specifically trained in the care of the pediatric patient. Blood tests and X-rays should be more readily available.

Neutrophils from Patients with Primary Ciliary Dyskinesia Display Reduced Chemotaxis to CXCR2 Ligands

Primary ciliary dyskinesia (PCD), cystic fibrosis (CF), and chronic obstructive airway disease are characterized by neutrophilic inflammation in the lungs. In CF and chronic obstructive airway disease, improper functioning of neutrophils has been demonstrated. We hypothesized that the pulmonary damage in PCD might be aggravated by abnormal functioning neutrophils either as a primary consequence of the PCD mutation or secondary to chronic inflammation. We analyzed chemotactic responses and chemoattractant receptor expression profiles of peripheral blood neutrophils from 36 patients with PCD, 21 healthy children and 19 healthy adults. We stimulated peripheral blood monocytes from patients and healthy controls and measured CXCL8 and IL-1β production with ELISA. PCD neutrophils displayed reduced migration toward CXCR2 ligands (CXCL5 and CXCL8) in the shape change, microchamber and microslide chemotaxis assays, whereas leukotriene B4 and complement component 5a chemotactic responses were not significantly different. The reduced response to CXCL8 was observed in all subgroups of patients with PCD (displaying either normal ultrastructure, dynein abnormalities or central pair deficiencies) and correlated with lung function. CXCR2 was downregulated in about 65% of the PCD patients, suggestive for additional mechanisms causing CXCR2 impairment. After treatment with the TLR ligands lipopolysaccharide and peptidoglycan, PCD monocytes produced more CXCL8 and IL-1β compared to controls. Moreover, PCD monocytes also responded stronger to IL-1β stimulation in terms of CXCL8 production. In conclusion, we revealed a potential link between CXCR2 and its ligand CXCL8 and the pathogenesis of PCD.

Sweat potassium concentration may help to identify falsification of sweat test : A case report

OBJECTIVES To document the relevance of sweat potassium concentration in a reported case of a white Caucasian 27-month-old boy who presented with non-specific respiratory symptoms and several abnormal sweat test results compatible with cystic fibrosis (CF). DESIGN AND METHODS Repeated sweat tests using the Gibson-Cooke technique in the presence and absence of the mother. RESULTS The high within- and between-test variability, the very low sweat potassium concentrations, several aspects of the familys history and a negative exhaustive genetic analysis to identify any CFTR mutation, raised suspicion for pediatric condition falsification. Two additional sweat tests performed in the absence of the mother were normal. CONCLUSION CF diagnosis was then discarded and a Munchausen syndrome by proxy diagnosis was proposed.

303 Smoking cessation help should be available at CF reference centres – a Belgian national survey of smoking in patients with cystic fibrosis

Background In Belgium in 2011, 35% of the 15–29 years age group were regular smokers. No information is available about epidemiology of smoking by CF patients in Belgium. Aims To identify active and passive smokers in the Belgian CF patients, to investigate the characteristics of addiction of active CF smokers. Methods Active and passive smokers were identified by means of urinary cotinine (UC) >100 ng/ml, measured by HPLC. Patients with positive UC were asked to meet with a tabacologist, to evaluate their expired CO, their physical, psychological and behavioural addiction to nicotine, and their HAD score. Results Preliminary analysis of 351 patients with complete data sets did not disclose any patient with positive UC before age 19.5. Overall, 30 out of 706 patients (4.5%, 78.8% of target) had a positive UC; 17 met the tabacologist (12 active smokers, 5 passive smokers). Most active smokers (28±10 y) were males (10/12). Mean UC of active smokers was 863±464 ng/ml, mean expired CO was 13.3±7.6 ppm, Fagestrom score was 4.5±3. Almost all active smokers (11/12) had attempted at least once to quit smoking and 5/12 (41%) smoked also cannabis. UC of active smokers was higher in patients with low SE status (1270 vs 747 ng/ml, p=0.04) and correlated with anxiety (R = 0.82, p=0.009). All smoking patients wished to receive specific help for smoking cessation at their CF centre. Conclusion Active or passive exposure to cigarette smoke was present in at least 4–5% of CF patients. Smoking cessation expertise should be available at CF reference centres.