Nasal Mucosa Of Children Research Articles

Kids' noses resist COVID-19.

Children resist COVID-19, and previous studies reported increased innate immunity in their upper airways. A new paper by Watkins et al. (https://doi.org/10.1084/jem.20230911) shows that the nasal mucosa of children is characterized by often asymptomatic viral and/or bacterial infections that dynamically regulate distinct innate immune programs.

Microbiome in Nasal Mucosa of Children and Adolescents with Allergic Rhinitis: A Systematic Review

The human upper respiratory tract comprises the nasal cavity, pharynx and larynx regions and offers distinct microbial communities. However, an imbalance and alterations in the nasal mucosa microbiome enhance the risk of chronic respiratory conditions in patients with allergic respiratory diseases. This is particularly important in children and adolescents once allergic rhinitis (AR) is an inflammatory disorder of the nasal mucosa, often associated with an increase in pulmonary allergic inflammation. Therefore, this systematic review aimed to collect scientific data published concerning the microbial community alterations in nasal mucosa of children and adolescents suffering from AR or in association with adenotonsillar hypertrophy (AH) and allergic rhinoconjunctivitis (ARC). The current study was performed using the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Publications related to microbiome alterations in the nasal mucosa in pediatric age, studies including next-generation sequencing platforms, and studies exclusively written in the English language were some of the inclusion criteria. In total, five articles were included. Despite the scarcity of the published data in this research field and the lack of prospective studies, the genera Acinetobacter, Corynebacterium, Dolosigranulum, Haemophilus, Moraxella, Staphylococcus and Streptococcus dominate the nares and nasopharyngeal microbiome of the pediatric population regardless of their age. However, an imbalance in the resident bacterial community in the nasal mucosa was observed. The genera Acinetobacter, and Pseudomonas were more abundant in the nasal cavity of AR and AH children, while Streptococcus and Moraxella were predominant in the hypopharyngeal region of AR infants. An abundance of Staphylococcus spp. was also reported in the anterior nares and hypopharyngeal region of children and adolescents suffering from AR passive smoke exposure and ARC. These records suggest that different nasal structures, ageing, smoke exposure and the presence of other chronic disorders shape the nasal mucosa microbiome. Therefore, the establishment of adequate criteria for sampling would be established for a deeper understanding and a trustworthy comparison of the microbiome alterations in pediatric age.

Acquired CFTR dysfunction and dense distribution of ionocytes in nasal mucosa of children with CRS

BackgroundIonocytes are rare cells in airway epithelium characterized by a high expression of CFTR.ObjectivesTo investigate the morphology and distribution of ionocytes and the function of CFTR in the nasal mucosal epithelium of children.MethodsThe exfoliated cells of nasal mucosa from 101 children were detected using flow cytometry to analyze the number of ionocytes and CFTR and the difference of CFTR function. Nasal mucosa and polyps were collected from 10 children with CRSwNP. The RNAscope of FOXI1 and CFTR was detected in pathological paraffin sections. The expression and distribution of ionocytes and CFTR in nasal mucosa and polyp epithelium were observed.ResultsIn CRS patients, the number of ionocytes in the nasal epithelium was lower and the number of ionocytes that did not express CFTR was higher, and the function of CFTR was also decreased. The expression of CFTR in the nasal mucosa of CRS showed the characteristics of local dense distribution and increased as the inflammation expanded. The ionocytes were “tadpole-shaped” in the epithelium and gathered in the area of high CFTR expression, the intracellular CFTR was expanded in clusters. Ionocytes that did not express CFTR was more common in the nasal polyps.ConclusionsThe number of ionocytes and the function of CFTR in nasal mucosa of CRS patients decreased. With the expansion of inflammation, CFTR and ionocytes showed more obvious dense distribution. Some ionocytes lost the expression of CFTR and did not show the "tadpole" shape, which may be related to the occurrence of polyps.

Differences in Bacterial Colonization and Mucosal Responses Between High and Low SES Children in Indonesia.

Increased nasopharyngeal carriage of pathogenic bacteria is found in low socioeconomic status (SES) settings. How SES affects local immune responses, important for controlling colonization, is currently unknown. Examining bacterial colonization and cytokine response in the nasal mucosa of children from high and low SES. Nasosorption samples were collected in October 2019 from 48 high SES and 50 low SES schoolchildren, in a cross-sectional study in Makassar, Indonesia. Twenty-five cytokines were measured in nasal fluid. Quantitative polymerase chain reaction was performed to determine carriage and density of Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis and Staphylococcus aureus. Data were analyzed using multivariate regression. H. influenzae and S. pneumoniae densities were increased in low SES settings compared to the high SES settings (P = 0.006, P = 0.026), with 6 and 67 times higher median densities, respectively. Densities of H. influenzae and S. pneumoniae were positively associated with levels of IL-1beta and IL-6. After correcting for bacterial density, IL-6 levels were higher in colonized children from high SES than low SES for H. influenzae and S. pneumoniae (both P = 0.039). Increased densities of H. influenzae and S. pneumoniae were observed in low SES children, whereas IL-6 levels associated with colonization were reduced in these children, indicating that immune responses to bacterial colonization were altered by SES.

Age-related Differences in the Nasal Mucosal Immune Response to SARS-CoV-2.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected more than 180 million people since the onset of the pandemic. Despite similar viral load and infectivity rates between children and adults, children rarely develop severe illness. Differences in the host response to the virus at the primary infection site are among the mechanisms proposed to account for this disparity. Our objective was to investigate the host response to SARS-CoV-2 in the nasal mucosa in children and adults and compare it with the host response to respiratory syncytial virus (RSV) and influenza virus. We analyzed clinical outcomes and gene expression in the nasal mucosa of 36 children with SARS-CoV-2, 24 children with RSV, 9 children with influenza virus, 16 adults with SARS-CoV-2, and 7 healthy pediatric and 13 healthy adult controls. In both children and adults, infection with SARS-CoV-2 led to an IFN response in the nasal mucosa. The magnitude of the IFN response correlated with the abundance of viral reads, not the severity of illness, and was comparable between children and adults infected with SARS-CoV-2 and children with severe RSV infection. Expression of ACE2 and TMPRSS2 did not correlate with age or presence of viral infection. SARS-CoV-2–infected adults had increased expression of genes involved in neutrophil activation and T-cell receptor signaling pathways compared with SARS-CoV-2–infected children, despite similar severity of illness and viral reads. Age-related differences in the immune response to SARS-CoV-2 may place adults at increased risk of developing severe illness.

Characterizing T cell subsets in the nasal mucosa of children with acute respiratory symptoms.

BackgroundIn infants admitted to an ICU with respiratory failure, there is an association between the ratio of CD8+ to CD4+ T cells within the upper respiratory tract and disease severity. Whether this ratio is associated with respiratory disease severity within children presenting to a pediatric emergency department is not known.MethodsWe studied a convenience sample of 63 children presenting to a pediatric emergency department with respiratory symptoms. T cell subsets in the nasal mucosa were analyzed by flow cytometry. We compared CD4+ and CD8+ T cells subsets in these samples and analyzed the proportion of these subsets that expressed markers associated with tissue residency.ResultsWe were able to identify major subsets of CD8 and CD4 T cells within the nasal mucosa using flocked swabs. We found no difference in the ratio CD8+ to CD4+ T cells in children with upper or lower respiratory illness. A positive association between tissue-resident memory T cell frequency and patient age was identified.ConclusionsIn our patient populations, the CD8+:CD4+ ratio was not associated with disease severity. The majority of T cells collected on nasal swabs are antigen experienced, and there is an association between the frequency of tissue-resident T cells and age.Impact Immune cell populations from the nasal mucosa can be captured using flocked nasal swabs and analyzed by flow cytometry.Nasal CD8+:CD4+ ratio does not predict respiratory illness severity in children presenting to the emergency department.The frequency of CD8+ and CD4+ resident memory T cells within the nasal mucosa increases with age.

Особенности локального воспаления слизистой оболочки носа у детей с бронхиальной астмой

Bronchial asthma (BA) is often associated with chronic inflammatory processes in the nasal mucosa; these processes give rise to allergic rhinitis (AR), chronic rhinosinusitis, adenoiditis and polypous rhinosinusitis. Due to their multiple symptoms, these diseases of the upper respiratory tract, especially allergic rhinitis, are often difficult to verify in patients with asthma. The aim of the study was to assess the features of local inflammation of the nasal mucosa in patients with BA and AR. Patients and methods. 93 children with BA were examined. General clinical, allergological, functional examination, measurement of endonasal temperature and determination of IgE and IL4 content in nasal secretions were performed. Results. Children with BA have lower values of endonasal temperature than healthy ones. There was a tendency to decrease endonasal temperature as the symptoms of AR increased. In the acute stage of AR, the temperature values were lower than in the remission stage, р = 0,02. The addition of infectious inflammation of the nasal mucosa in children with AD was accompanied by an increase in endonasal temperature, р = 0,04. The increase of the content of nasal IgE in acute AR – 115,6 (49,9; 181,2) ME/mg, compared to the remission period to 24,9 (6,2; 43,7) ME/mg. Exacerbation of AR was associated with increased IL4 to 109,7 (54,2; 165,2) PG/mg, in the period of remission – 34,4 (12,0; 56,8) PG/mg. The increase of these biomarkers of allergic inflammation have a correlative relationship, R = 0,44, p = 0,002. The relationship of IL4 content with endonasal temperature, R = 0,44 р = 0,02 was established. Conclusion. Patients with BA and AR showed a decrease in endonasal temperature compared to healthy ones. Exacerbation of AR in children with BA characterized by an increase in the content of nasal IgE and IL4 and a decrease in endonasal temperature, which allows us to consider these indicators as biomarkers of activation of allergic inflammation.

Pirometaxine™ (Narlisim™) in pediatric nasal congestion: a retrospective study.

Nasal congestion represents a troublesome health issue which is especially and invalidating in children. Effective nasal drugs, such as sympathomimetic drugs, are usually forbidden in children under 12 years of age because of their potential systemic adverse effects. Hypertonic nasal physiological solutions have recently been successfully used to decongest nasal mucosa in children: its mechanical activity has been universally recognized as safe and effective and it represents a well-established, useful treatment in children. We have retrospectively analyzed a case series of 40 children treated for 4 days (96 hours) with a new class 1s medical device nasal hypertonic spray containing Pirometaxine™ (Narlisim™) in outpatient affected by nasal congestion due to common cold. Every child was evaluated on a 3-point symptom assessment scale (0: no symptom; 1: mild symptom; 2: moderate symptom; 3: severe symptom) at the beginning of the trial (T0) and after 48 (T1) and 96 hours (T2). The symptoms assessed were nasal obstruction, nasal secretion, headache, flash of cold, pharyngodynia, cough, and sneeze. The results, in terms of short-term efficacy to control nasal obstruction (T1 vs. T0: P<0.0001; T2 vs. T0: P<0.0001), nasal secretion (T1 vs. T0: P<0.0001; T2 vs. T0: P<0.0001) and all the symptoms related to common cold have supported the efficacy of this hypertonic nasal solution. No adverse events have been pointed out during the trial supporting the safety of this new nasal hypertonic approach. The absence of adverse events after 48-96 hours along with the short-term effectiveness of this new treatment seems to represent a new, safe option to treat children affected by nasal congestion secondary to common cold. Considering the current lack of safe treatments for children under 12 years of age, Narlisim™ can be considered as a useful short-term option to control nasal congestion in children.

The features of microcirculation in the nasal mucosa in children with adenoid hypertrophy and otitis media with effusion

The features of microcirculation in the nasal mucosa in children with adenoid hypertrophy and otitis media with effusion

Clinical and Laboratory Efficacy and Safety of ValeVita Rinogel Spray and Nazo-Vit Use in Treatment of Children with Acute Postvirus Rhinosinusitis

The objective: to evaluate the effectiveness of the therapeutic effect, the overall and local tolerance of ValeVita Rinogel Spray and ValeVita Nazo-Vit in treatment of children with acute postvirus rhinosinusitis (APRS).Materials and methods. The clinical study included 30 children (17 boys and 13 girls) who were on an outpatient treatment in ENT department of the city’s Children’s Clinical Hospital №1 in Kyiv. The age of patients ranged from 8 to 15 years old (mean age 11.5±0.5 years old). The main group of children (n=15) used ValeVita Rinogel Spray and ValeVita Nazo-Vit; the control group (n=15) used nasal decongestants (xylometazoline) and sodium chloride 0.9%. In children of both observed groups there were evaluated clinical symptoms of APRS, microbiological and cytomorphological studies of the nasal mucosa before and after the treatment.Results. According to the analysis of rhinoscopic and endoscopic examination there was a more rapid regress of clinical symptoms of APRS in children of the main group compared with the control group. Cytomorphological study in the main group noted a significant decrease of inflammatory cells (eosinophils, neutrophil granulocytes, lymphocytes) in nasal mucosa of children with APRS during treatment period compared with children of the control group. Combined use of ValeVita Rinogel Spray and ValeVita Nazo-Vit in the main group promoted normalization of immune clearance of nasal mucous lining as manifested by decrease of pathogenic organisms compared with the control group. During observation time no complications, side effects associated with the use of ValeVita Rinogel Spray and ValeVita Nazo-Vit were noted in patients.Conclusion. Combination of ValeVita Rinogel Spray and ValeVita Nazo-Vit is effective and safe in the treatment of acute postvirus rhinosinusitis in children 8-15 years old, does not cause local and general pathological changes, as evidenced by performed clinical and laboratory examination of patients.

Nasal Cytology as a Marker of Atopy in Children.

The aim of this study was to evaluate the cytological picture of nasal mucosa in children with atopic diseases and to determine the diagnostic value of the test for the diagnosis of atopic diseases. The study included 140 children from 4 months to 17 years old. Among children with a history of atopy, there were 30 children with atopic dermatitis, 30 children with asthma, and 46 children with allergic rhinitis. The control group consisted of 34 healthy children. The nasal scraping technique has been used to collect samples from the nasal cavity. The samples were evaluated under light microscope. Epithelial cells as well as infiltrating cells were assessed. The only statistically significant group of cells differentiating children with atopic disease and without atopy were eosinophils, which in children with atopy were significantly more common. Assuming a significant eosinophilia value of at least 5% of all cells in cytogram, the sensitivity of nasal cytology in allergic rhinitis was 52.2%, in asthma 33.3%, and in atopic dermatitis 13.3%. The specificity of the test in atopic diseases was 94.1%. It can be concluded that nasal cytology with eosinophilia assessment can be a useful tool for an early diagnosis of atopic disease in children.

Effect of cigarette smoke on counts of immunoreactive cells to eotaxin-1 and eosinophils on the nasal mucosa in young patients with perennial allergic rhinitis

IntroductionIn teenagers with perennial allergic rhinitis, exposure to tobacco cigarette smoke increases the count of eosinophils in the nasal mucosa; the recruitment of eosinophils arises from the combined action of a number of cellular and molecular signals, including eotaxin. ObjectiveTo assess the effect of exposure to tobacco cigarette smoke on the count of immunoreactive cells to eotaxin-1 and eosinophils on the nasal mucosa of children and teenagers with perennial allergic rhinitis. MethodsIn a cross-sectional study, forty-four patients were evaluated (aged 7–19 years old): 22 with and 22 with no exposure to tobacco cigarette smoke. After replying to 2 validated questionnaires, on Asthma and Allergies in Childhood and on the severity of nasal symptoms, nasal mucosal samples were obtained by scraping the middle one-third of the inferior turbinates. Then counts of immunoreactive cells to eotaxin-1 and eosinophils were assessed by immunohistochemistry. ResultsPatients with exposure to tobacco cigarette smoke showed higher cell counts of both eotaxin-1 and eosinophils than patients with no exposure to the smoke, with no correlation between the two variables. However, both counts, of eotaxin-1 and eosinophils, were related to the cotinine/creatinine ratio. ConclusionsExposure to tobacco cigarette smoke can increase eotaxin-1 and the count of eosinophils in the nasal mucosa of young patients with perennial allergic rhinitis.

Effect of passive smoking on the ultrastructure of the nasal mucosa in children

Passive exposure to cigarette smoke has been implicated in a number of respiratory childhood disorders. Most studies concerning smoking were directed to its carcinogenic effect on the lungs. However, the effects of smoking on nasal respiratory mucosa have not been widely studied. The aim of the present study was, therefore, to study the ultrastructural changes in the nasal mucosa of a pediatric population exposed to passive smoking. The study included 20 children between the ages of 5 and 11 years, who were scheduled for tonsillectomy and at the same time had a positive history of prolonged exposure to household passive smoke. Another 10 children with a negative household smoking history were included as a control group. All children were nonatopic and with a negative family history of allergy. None of them had adenoids or infective rhinosinusitis. At the time of surgery, a 1-mm(3) biopsy was taken was taken from the lower border of the inferior turbinate. The specimens were processed and examined with electron microscopy Examination of the nasal mucosa showed several ultrastructural changes. These included patchy loss of cilia, generalized loss of cilia, squamous metaplasia, hyperplasia of goblet cells and seromucinous acini, and vascular congestion. More severe changes were observed with longer passive exposures to cigarette smoke. The study did not disclose any evidence of ongoing allergic reaction or neoplastic transformations. Children exposed to passive cigarette smoke may develop several structural changes in the respiratory nasal mucosa with subsequent negative effects on its ciliary activity and mucociliary function. As a result of these effects, defense mechanisms of the nose may be ruined or lost, and those children may develop persistent sinonasal infections. Exposure of these children to passive smoking for longer periods of time may also induce other significant changes that were not detected in the present study.

Chronic rhinosinusitis in children—Bacteriological analysis in terms of cytological examination

IntroductionThe mechanisms of inflammatory response occurring in chronic rhinosinusitis in children are multifactorial. Besides the history and a physical examination, amongst diagnostic tools there are cytological and bacteriological examinations. Objectives1Determining the nature of the bacterial flora present in the nasal cavities and paranasal sinuses in children with chronic rhinosinusitis amongst patients of The Department of Paediatric Otolaryngology, Warsaw Medical University.2Determining the relation between bacterial strains and cytological examination of nasal mucosa in children with chronic rhinosinusitis. Materials and methodsThe study group included 64 patients with chronic rhinosinusitis without polyps. The control group included 30 randomly chosen children. Diagnostic tests performed in both groups were: middle meatal culture and cytological examination from the inferior nasal concha and middle meatus. Statistical analysis was accomplished with Statistica 8.0. Results1The most common strains of bacteria found in patients with chronic rhinosinusitis are gram-positive bacteria such as coagulase-negative staphylococci and Staphylococcus aureus, and gram-negative bacteria such as: Haemophilus influenzae and Moraxella catarrhalis.2The analysis of relation between bacterial strains and nasal cytology revealed:(a)The presence of the coagulase-negative staphylococci was correlated with less severe inflammatory changes, expressed by a higher count of epithelial columnar cells and lower count of neutrophils in the cytology results.(b)The presence of S. aureus was associated with a significantly higher percentage of squamous cells in cytology obtained from the middle nasal turbinate (for S. aureus found in the maxillary sinus). This observation suggests drawing attention to the transformation of mucosa into squamous, as a possible risk factor for colonisation of S. aureus in the maxillary sinus.(c)Occurrence of H. influenzae and M. catarrhalis in the smear correlated with a greater potential for infection, expressed by a significantly higher count of neutrophils. ConclusionsDamage to the respiratory epithelial surface is understood as damage to the innate immune barrier, and repeated antibiotic therapy with the subsequent repopulation of the epithelium accidentally by various bacteria can become responsible for the pathogenic effect of bacteria in chronic rhinosinusitis.

Objective assessments of allergic and nonallergic rhinitis in young children

Allergic and nonallergic rhinitis are common childhood disorders. To study nasal eosinophilia and nasal airway patency in young children with allergic and nonallergic rhinitis to assess the pathology behind such diagnoses. We investigated 255 children at six years of age from the Copenhagen Prospective Study on Asthma in Childhood birth cohort assessing rhinitis history, specific immunoglobulin E relevant to rhinitis symptoms, nasal eosinophilia and nasal airway patency by acoustic rhinometry before and after decongestion. Associations were studied in a multivariate graphical model corrected for gender, height and nasal steroid usage. Allergic rhinitis was significantly and directly associated with irreversible nasal airway obstruction (reduced decongested nasal airway patency) (P = 0.004), whereas nonallergic rhinitis was not. Both allergic rhinitis (P = 0.000) and nonallergic rhinitis (P = 0.014) were directly and significantly associated with nasal eosinophilia, but this association was stronger for allergic rhinitis. Allergic rhinitis and nonallergic rhinitis are of different pathologies as suggested from their different associations not only to allergy but importantly also to irreversible nasal airway obstruction and eosinophilic inflammation. Allergic rhinitis was significantly associated with nasal eosinophilia and irreversible nasal airway obstruction suggesting chronic inflammation and structural remodeling of the nasal mucosa in children at the age of 6 years. Nonallergic rhinitis exhibited no change in the nasal airway patency, but some nasal mucosal eosinophilia albeit less than children with allergic rhinitis.

Increased CD3, Tryptase, and IFN-ψ immunoreactivity in nasal mucosa of children following Ex vivo challenge with lipopolysaccharide

Increased CD3, Tryptase, and IFN-ψ immunoreactivity in nasal mucosa of children following Ex vivo challenge with lipopolysaccharide

The Ultrastructure of Nasal Mucosa in Children with Asthma

Nasal brushing has sometimes been used to characterize some affections of the respiratory tract, but seldom employed in chronic diseases such as asthma, for the possible presence of cellular inflammation in the small specimens used for electron microscopy. The present study evaluated the ultrastructure of epithelial cells obtained by nasal brushing in 11 allergic children with asthma, before and after staying in an environment free of allergens, usually implicated in the genesis of inflammatory events. The ultrastructural alterations of the nasal mucosa have been graded on the basis of their severity. Grade I lesions were characterized by well-differentiated mucous and ciliated cells. The ciliated cells appeared usually well preserved but decreased in number. In grade II lesions, most of the epithelial surface was covered by mucous cells. A further phenotype composed of poorly differentiated ciliated or mucous cells was detected. Grade III lesions showed aspects of depletion of the ciliated and mucous cells. The epithelium was largely composed of undifferentiated cells. Furthermore, the comparison of specimens at 2 different times of sampling did not differ. The data demonstrate that in allergic children with asthma, the nasal mucosa showed ultrastructural changes, which appeared to be unmodifiable during a prolonged stay in an environment free of allergens. Moreover, the nasal epithelium may provide a convenient sampling site, allowing grade of mucosal damage, with the benefit that the brush method is minimally invasive and avoids complications related to bronchoscopic examination.

The nasal mucosa of children with nocturnal enuresis before and after treatment with 1-deamino 8- d-arginine vasopressin spray

Intranasal administration of 1-deamino 8- d-arginine vasopressin (DDVAP) used for treatment of nocturnal enuresis (NE), might be expected to have various effects on the nasal mucosa, e.g. altering the clearance by the mucociliary apparatus. We evaluated two samples (brushes) of epithelial surface cells from the nasal mucosa, one from each nostril, of 18 children (ten males and eight females) with a mean age of 7.7 years (range: 5–13 years) who were affected by primary NE. Samples were taken before and 1 and 6 months after administration of DDVAP spray. No qualitative changes in the epithelial surface cells from nasal mucosa were recognized and only non-statistically significant increases in percentages of goblet, ciliated, basal and unciliated cells at 1 and 6 months after therapy were observed. Thus, it appears that DDVAP spray can be used for at least 6 months in children without apparent risk of damage to the epithelial surface cells from the nasal mucosa.

Differences in nasal cellular infiltrates between allergic children and age-matched controls.

Little is known about the cellular infiltrates in the nasal mucosa of children. This study was set up to compare the nasal cellular infiltrates in biopsy specimens from allergic children and controls. Atopic children were distinguished from controls on the basis of symptoms of allergic rhinitis and/or asthma, total serum immunoglobulin (Ig)E, family history and specific serum IgE to food and aeroallergens. Fifteen allergic patients (median age 4.3 yrs) and 15 age-matched nonallergic control subjects were evaluated. The number of cells positive for CD1a, CD4, CD8, CD19, CD68, chymase, tryptase, IgE and major basic protein was determined in the mucosa of the inferior turbinate. A significantly higher number of IgE-positive cells and mast cells was found in the epithelia of the allergic group. In the lamina propria, higher numbers of IgE-positive cells and eosinophils were found. Langerhans' cells positive for IgE were only seen in allergic children with specific serum IgE against aeroallergens. These children also had a higher number of IgE-positive mast cells compared to controls and atopic children without specific serum IgE. These results show that the nasal cellular infiltrates of allergic children differ from nonallergic control subjects. Prior to the detection of specific serum immunoglobulin E, cellular changes can be found in the nasal mucosa of atopic children.

The "nasal pool"-device for challenge and lavage of the nasal mucosa in children: histamine-induced plasma exudation responses.

The accessibility of the nasal airway allows important examination of the airway mucosa in health and disease. However, the current methods for nasal challenge and lavage in children suffer from several shortcomings. In the present study, we have assessed the utility of a recently developed "nasal pool"-device in 7-9 year old children, and explored the ability of the nasal mucosa of these school-children to mount a plasma exudation response (lumenal entry of bulk plasma). Isotonic saline was instilled and maintained (1 min) as a "pool" in the unilateral nasal cavity. Recovery of the "pool" (lavage fluids) was determined. Concomitant challenge and lavage was then performed by exposing the nasal mucosa to a "pool" of isotonic saline and histamine (40-400 micrograms/ml) for 2 min. "Pool" fluids were analysed for alpha 2-macroglobulin as an index of microvascular-epithelial exudation of bulk plasma. The school-children successfully managed to carry out nasal lavages as well as concomitant histamine challenges and lavages with the "nasal pool"-device. The recovery of the nasal lavage fluids was almost quantitative (> 85%) and thus well reproducible. Histamine produced significant exudation of bulk plasma (alpha 2-macroglobulin). We suggest that the "nasal pool"-device is well suited for challenge and lavage of the nasal airway mucosa in children above 6 years of age, and conclude that lumenal entry of multipotent humoural protein-systems may be an important first line respiratory defence mechanism in children.