Removal of airway foreign body using flexible bronchoscopy in children.

BACKGROUND: Flexible bronchoscopy is mainly used to diagnose airway foreign bodies (AFBs). Due to advances in pediatric anesthesia, many teams have considered the extraction of AFBs by flexible bronchoscopy. We aimed to assess the success of flexible bronchoscopy in AFB removal in children. PATIENTS AND METHODS: We analyzed retrospectively the data of children admitted for AFB aspiration in the Pediatric Respiratory Diseases Department B of Abderrahmane Mami Hospital in Tunisia between January 2012 and December 2022. AFB removal was performed by flexible bronchoscopy through the use of a laryngeal mask airway (LMA) or intubation. RESULTS: Of the 105 children included, AFB was removed by flexible bronchoscopy in 99 children (94.3 %). The mean age of the children was 32 months (9-150 months) with a sex ratio of 2:3. The foreign body was organic in 67 % of cases. Overall, 37 children underwent rigid bronchoscopy first (35.2 %). Flexible bronchoscopy was performed through the LMA in 77 cases (73 %) and after intubation in the other cases. Thoracic surgery was needed in two cases (1.9 %). Four infants expectorated the AFB after the procedure (3.8 %). Only two children developed laryngeal edema with transient oxygen desaturation. CONCLUSION: AFB removal using a flexible bronchoscope is an efficient and safe procedure when performed by an experienced team. The recent use of LMA has facilitated the use of a larger bronchofiberscope and the insertion of multiple tools that can reach distal airways.

Spindle cell hemangioma of the lung: An unusual presentation.

Spindle cell hemangioma (SCH) is a benign vascular tumour, first identified by Weiss and Enzinger in 1986. Habitually, the SCH affects almost exclusively the dermis and subcutaneous tissues of distal extremities. So far, only 2 cases have been described in the lung. We describe herein the third case of SCH occurring in the lung in a 47 year-old woman. The patient was successfully treated by right lower lobectomy. The histopathological and immunohistochemistry examination of the excised tumour leads to the definitive diagnosis. Our case is instructive by its different clinical and radiological presentation compared to the previous two cases.

Diagnostic challenge in a series of eleven patients with hyper IgE syndromes.

Hyper IgE syndromes (HIES) is a heterogeneous group of Inborn Errors of Immunity characterized by eczema, recurrent skin and lung infections associated with eosinophilia and elevated IgE levels. Autosomal dominant HIES caused by loss of function mutations in Signal transducer and activator of transcription 3 (STAT3) gene is the prototype of these disorders. Over the past two decades, advent in genetic testing allowed the identification of ten other etiologies of HIES. Although Dedicator of Cytokinesis 8 (DOCK8) deficiency is no more classified among HIES etiologies but as a combined immunodeficiency, this disease, characterized by severe viral infections, food allergies, autoimmunity, and increased risk of malignancies, shares some clinical features with STAT3 deficiency. The present study highlights the diagnostic challenge in eleven patients with the clinical phenotype of HIES in a resource-limited region. Candidate gene strategy supported by clinical features, laboratory findings and functional investigations allowed the identification of two heterozygous STAT3 mutations in five patients, and a bi-allelic DOCK8 mutation in one patient. Whole Exome Sequencing allowed to unmask atypical presentations of DOCK8 deficiency in two patients presenting with clinical features reminiscent of STAT3 deficiency. Our study underlies the importance of the differential diagnosis between STAT3 and DOCK8 deficiencies in order to improve diagnostic criteria and to propose appropriate therapeutic approaches. In addition, our findings emphasize the role of NGS in detecting mutations that induce overlapping phenotypes.

Giant pulmonary hydatid cyst in children.

Hydatid disease is still endemic in Tunisia. It is mostly seen in young people less than 40 years and children are affected in one third of cases. The lungs are the predominant location in children. Our study aims to define the particularities of children PHC's (pulmonary hydatic cyst) management, the characteristics of giant cyst and to study predictive factors of complications. We included retrospectively 105 children with PHC followed between 1999 and 2019. Patients were aged less than 16 years with surgically confirmed diagnosis of PHC. Two groups of cysts were defined: giant cysts which were 10 cm across or more, and no giant cysts.The sex-ratio was 1.38 with a mean age of 10.5±3 years. The symptomatology was dominated by cough (59%), thoracic pain (51%) and hemoptysis (46%). Giant cysts were observed in 24 (22.9%) patients. Dyspnea (29% vs 5% p<0.001) and thoracic pain (88% vs 41% p<0.001) were significantly more frequently reported in giant cysts. Eighty-six patients had a single cyst (83%) and 19 had multiple cysts (17%). Giant cysts accounted for 22,9% (24 cases). Thoracic ultrasonography was diagnostic in 77.4%. The thoracic CT scan was performed in 27 children with inaccessible cysts in thoracic ultrasonography or in diagnostic doubt.Patients were all treated surgically. Surgical procedures consisted of cystectomy (59%), pericystectomy (18%) and pulmonary resection when parenchyma was destroyed (23%). Parenchymal resection was more often performed in complicated cysts (27% vs 20% p>0.05) and in giant cysts (41% vs 18% p<0.05). A two-stage thoracotomy was performed in the 4 patients with bilateral cysts. Thirteen patients presented immediate post-operative complications which occurred more frequently in complicated and giant cysts. Hospital stay was longer in complicated cysts (16±9 days vs 7±3 days; p<0.001) and in giant cysts (14±9 days vs 11±8 days; p>0.05). In endemic regions, the diagnosis of PHC in children should be based on the combination of thoracic radiography and ultrasonography which are effective, not costly, safe and accessible. Complicated and giant PHC cause lung damage leading to extensive parenchymal resection. They are more associated with post-operative complications prolonging hospital stay and increasing expenses.

Giant pulmonary hydatid cyst in children.

BACKGROUND: Lungs are the second most common site for hydatid disease after the liver. Giant hydatid cyst (GHC) of the lung is a special clinical entity in children and is related to higher lung tissue elasticity. AIM: To compare clinical and imaging features, types of surgical interventions, and postoperative complications in pulmonary GHC and non-giant pulmonary hydatid cysts (NGHC) in children. METHODS: A retrospective study was undertaken. The data analyzed were taken from medical records of children with pulmonary hydatid cyst (PHC) hospitalized in a pulmonary department in Tunisia between January 2004 and February 2019. Cysts were divided according to their size into GHC ( ≥10cm) and NGHC (<10cm). RESULTS: In the study period, 108 PHC were recorded in 84 children. GHC accounted for 21 (19.4%) and NGHC for 87 (80.6%). The median of age of the children was 11 years (IQR 1-9, IQR 3-14) and the mean age was 11.6 years (10.5 in GHC vs. 11.4 years in NGHC). Hemoptysis was found in 25% of the GHC group vs. 48.4% of the NGHC group (P=0.27). Cysts were multiple in 23.8% of cases and predominated in the right in 64.3% of cases and in the inferior lobes in 71.4% of the cases. GHCs were less frequently complicated (60% vs. 78.1% in NGHC, P≤0.11), although not significantly. Parenchymal resection was realized in 50% of GHC vs. 18.8% of NGHC (P=0.006). No significant difference was found in postoperative complications between the two groups and there was no recurrence in either group. CONCLUSION: GHC is a special clinical entity in children. It requires major surgery with parenchymal resection, and therefore early diagnostic and therapeutic management is warranted.

Features of patients with 2019 novel coronavirus admitted in a pneumology department: The first retrospective Tunisian case series.

AIM: On 2 March 2020, Tunisia has reported the first confirmed case of COVID-19. Since then, the disease has affected about 700 persons in the country. The purpose of our study was to report epidemiological, clinical, radiological and therapeutic features of patients with 2019-nCoV infection admitted in the pneumology department. METHODS: We extracted the data of the consequetive 20 patients managed in the department of pneumology B at Abderrahmen Mami hospital, from March, 26 to April, 8, 2020. RESULTS: The median age was 61 years old [41-85]. There were 9 men and 11 women.  Underlying disorders were observed in 16 patients (80%). Five patients were health care workers. Three patients did not have any known exposure. Common symptoms included fever (100%), shortness of breath (70%) and cough (70%). Computed tomography scans showed bilateral ground glass opacities in 7/9 cases. Fifteen patients received both chloroquine and azithromycin. Fourteen patients (70%) were discharged before April, 8, 2020. Reported complications were: hypokalemia (3 cases), pulmonary embolism (2 cases) and QT prolongation (1 case). One patient died from acute cardiac injury. CONCLUSION: Knowing the different aspects of moderate and severe forms of the disease can contribute to advance in infection control strategies.

Th 9 cells in Behçet disease: Possible involvement of IL-9 in pulmonary manifestations.

Behçet disease (BD) is a multisystemic disease some of whose manifestations are characterized by pulmonary involvements. The purpose of the study was to evaluate the level of T-helper type 9 (Th9) cells and the cytokine interleukin (IL)-9 in peripheral blood and in bronchoalveolar lavage (BAL) of patients with Behçet's disease (BD) affected by pulmonary manifestations. Nevertheless, until recently there have been no studies on its role in BD. The Th9 (CD4+IL-9+T) cell, transcription factor PU.1 and IL-9 mRNA levels, as well as serum and BAL IL-9 concentration, were measured in BD patients and healthy controls. The Th9 cell percentage and absolute number, PU.1 and IL-9 expression levels of BD patients were all increased significantly compared with the control group. Absolute number of Th9 cells was particularly increased in patients with active BD compared to inactive BD patients. The levels of IL-9 associated to Th9 expression depended on BD severity. These parameters were markedly expressed in the BAL of BD patients with pulmonary manifestations. IL-17 and the epithelial inflammatory cytokine TSLP were significantly correlated to IL-9 levels. This cytokine trio decreased in inactive BD patients after corticosteroïd treatment. In addition, IL-9 levels were correlated to CD4+ IL-9+ cells in BAL and in PBMCs. LPS stimulated PBMCs and macrophages induced increased secretion of IL-9 and the encoding transcription factors PU.1 and IRF4. In conclusion, the expansion of the Th9 cell subset, up-regulation of the PU.1 transcription factor and increased secretion of the IL-9 cytokine may contribute to the pathogenesis of BD, which may be supported by the increased release of IL-17 and TSLP. We provide evidence that Th9 T cells are increased in BD patients with pulmonary manifestations. This suggests an important role of IL-9 in the pathogenesis of BD particularly in patients suffering from lung involvement.

Association Between Vitamin D Metabolism Gene Polymorphisms and Risk of Tunisian Adults' Asthma.

INTRODUCTION: Several studies have shown a strong correlation between the serum vitamin D level and asthma severity and deficits in lung function. OBJECTIVE: Study the relationship between vitamin D and the severity of asthma by targeting five SNPs of vitamin D metabolism gene pathway in a Tunisian adult asthmatics population. METHODS: Our case-control study includes 154 adult asthmatic patients and 154 healthy Tunisian subjects. We genotyped many variants in three human genes encoding key components of the vitamin D metabolism, CYP2R1, CYP27B1, GC. The GC gene rs4588 and rs7041 polymorphisms were analysed using the PCR-RFLP method, while rs10741657 and rs12794714 for CYP2R1 gene and rs10877012 of CYP27B1 gene were investigated using TaqMan PCR genotyping techniques. RESULTS: We found that the presence of at least one copy of the rs12794714 A, allele was associated with lower risk of developing asthma (OR 0.61). Further, the rs12794714 is a protector factor against asthma severity (OR 0.5). However, the presence of rs10877012 TG genotype is a risk factor related to asthma severity (OR 1.89). When we classified the population according to sex, our results showed that rs10877012 TT genotype was a risk factor for women subjects (OR 6.7). Moreover, the expression of TT genotype was associated with a higher risk of asthma in non-smoker patients (OR 7.13). We found a significant lower VD serum levels in asthmatics than controls but no impact of the polymorphisms on VD levels. CONCLUSIONS: We found that rs12794714 and rs10877012 SNPs were associated with asthma risk.

Childhood tuberculosis: A descriptive study in a pneumo-pediatrics department in Tunisia.

Objective to assess the different localizations of tuberculosis (TB) in children in a pneumopediatric department in Tunisia and to describe its diagnosis tools since clinical investigations of childhood TB are challenged by the paucibacillary nature of the disease and the difficulties in obtaining specimens. Methods Forty-six cases of TB in children were studied between 2008 and 2013. Clinical history, examination and chest radiography were reported. Several investigations have been conducted to confirm the diagnosis of TB such as: tuberculin skin test (TST), bacteriological and histological investigations. Anti-tuberculosis treatment was prescribed according to the national guidelines. Results Cough and deterioration in general condition were the most frequent symptoms (47.8% and 43.7%). The other children presented cervical swelling (19.5%), chest pain (17.4%) and hemoptysis (4.3%). Abnormalities have been found in chest radiography in 35 cases (76%). TST was positive in 73% of cases. Diagnosis of TB was confirmed in 56.6% of cases by Mycobacterium tuberculosis (MT) isolation and/or biopsy. The diagnosis was made on presumptive arguments in 20 cases (43.4%) based on a history of TB contact, suggestive symptoms and a positive TST. A surgical biopsy was necessary for diagnosis in 17 cases (nasopharynx, bone, cervical, mediastinal and mesenteric lymph nodes). Pulmonary TB was diagnosed in 52% of cases. Two children were diagnosed with disseminated TB. A diagnosis delay was noted with an average of 20 days and a contact history was found in 52% of the children. All children were treated according to the national guidelines without major side effects. Healing without sequelae was achieved in 91% of cases. Conclusion Children represent a population at high risk for TB especially after a household contact with a higher frequency of multifocal forms compared to adults. The difficulty of the diagnosis in children may explain partially the diagnosis delay, but efforts must be done to improve prevention and diagnosis in our country.

Increased expression of thymic stromal lymphopoietin in induced sputum from asthmatic children.

OBJECTIVE: Thymic stromal lymphopoietin (TSLP) plays a role in amplifying the inflammatory response in asthmatics. TSLP is also a critical factor in airway remodeling airways. The aim of this study was to assess the expression of TSLP in induced sputum from asthmatic children and to look to the impact of TNF-α and IL-37 on TSLP production in induced sputum from asthmatic children. METHODS: Forty children with well-controlled asthma (20 moderate and 20 mild asthmatics) were studied. TSLP was measured by enzyme-linked immunosorbent assay (ELISA) in induced sputum (IS) samples, and compared with 22 age- and sex-matched healthy controls. Real-time quantitative PCR was used to determine TSLP mRNA expression in induced sputum cells. Sputum cells (ISCs) from 5 moderate asthmatics and 5 healthy controls (HC) were stimulated either with TNF-α or TNF-α plus recombinant IL-37 (rIL-37) comparing the suppression on TSLP production. RESULTS: The expression of TSLP mRNA in asthmatic patients was significantly higher than that observed in healthy controls [P=0.0001]. Induced sputum fluid TSLP and TNF-α levels were significantly higher in asthmatic patients compared to healthy controls and their levels depend on asthma severity. Sputum cells produced high TSLP levels upon stimulation with TNF-α (10pg/ml) in asthmatics. TSLP is merely produced by bronchial epithelial cells. Addition of recombinant IL-37 suppressed partially TSLP production in sputum-cultured cells and in bronchial epithelial cultured cells. CONCLUSIONS: The increase in TSLP and TNF-α level observed in IS fluid was found to correlate with disease severity. The increased TSLP production from asthma sputum cells was abrogated by the addition of rIL-37. Regulation of TSLP pathway may be a therapeutic approach for asthma.

Anti-inflammatory activity of IL-37 in asthmatic children: Correlation with inflammatory cytokines TNF-α, IL-ß, IL-6 and IL-17A.

BACKGROUND: The aim of this study was to assess interleukin (IL)-37 production in asthmatic children in serum and induced sputum and to look to the impact of IL-37 on pro-inflammatory cytokines production (TNF-α, IL-6, IL-1ß and IL-17). METHODS: Forty children with well-controlled asthma (20 moderate and 20 mild asthmatics) were studied. IL-37 was measured by ELISA in serum and induced sputum (IS) samples, and compared with 22 age- and sex-matched healthy controls. Real-time quantitative PCR was used to determine IL-37 mRNA expression in induced sputum cells. Induced sputum mononuclear cells from 10 moderate asthmatics and 10 healthy controls were stimulated either with lipopolysaccharides (LPS) or LPS plus recombinant IL-37 (rIL-37) comparing pro-inflammatory cytokines production. TNF-α, IL-1ß, IL-6 and IL-17 were measured by RT-PCR and ELISA. FINDINGS: The expression of IL-37 mRNA in asthmatic patients was significantly lower than that observed in healthy controls (P=0.0001). IL37 mRNA expression depended on asthma severity. Serum and IS IL-37 levels were significantly lower in asthma patients compared to healthy controls. LPS-stimulated sputum cells from asthma patients produced higher levels of IL-1ß, IL-6, and TNF-α than those from HC. Adding rIL-37 suppressed TNF-α, IL-1ß and IL-6 production in IS cells. In the same way, stimulating IS CD4(+) T cells in the presence of rIL-37 inhibited IL-17 production both in asthma patients and HC. IL-37 effect on IL-17 was more pronounced in patients than controls. INTERPRETATION: The decrease in IL-37 level observed in IS was found to correlate with disease severity. The increased pro-inflammatory cytokines production from asthma IS cells was abrogated by the addition of rIL-37. IL-37 could be an important cytokine in the control of asthma by suppressing the production of inflammatory cytokines.

Report of the Tunisian Registry of Primary Immunodeficiencies: 25-Years of Experience (1988-2012).

PURPOSE: Primary immunodeficiencies (PIDs) are a large group of diseases characterized by susceptibility to not only recurrent infections but also autoimmune diseases and malignancies. The aim of this study was to describe and analyze the distribution, clinical features and eventual outcome of PID among Tunisian patients. METHODS: We reviewed the record of 710 patients diagnosed with Primary Immunodeficiency Diseases (PIDs) from the registry of the Tunisian Referral Centre for PIDs over a 25-year period. RESULTS: The male-to-female ratio was 1.4. The median age at the onset of symptoms was 6 months and at the time of diagnosis 2 years. The estimated prevalence was 4.3 per 100,000 populations. The consanguinity rate was found in 58.2 % of families. According to the International Union of Immunological Societies classification, spectrums of PIDs were as follows: combined T-cell and B-cell immunodeficiency disorders account for the most common category (28.6 %), followed by congenital defects of phagocyte (25.4 %), other well-defined immunodeficiency syndromes (22.7 %), predominant antibody deficiency diseases (17.7 %), diseases of immune dysregulation (4.8 %), defect of innate immunity (0.4 %) and complement deficiencies (0.4 %). Recurrent infections, particularly lower airway infections (62.3 %), presented the most common manifestation of PID patients. The overall mortality rate was 34.5 %, mainly observed with combined immunodeficiencies. CONCLUSION: The distribution of PIDs was different from that reported in Western countries, with a particularly high proportion of Combined Immunodeficiencies and phagocyte defects in number and/or function. More is needed to improve PID diagnosis and treatment in our country.

Vitamin D reduces the differentiation and expansion of Th17 cells in young asthmatic children.

Vitamin D [25(OH)D3] deficiency has been associated with asthma as in many inflammatory and autoimmune pathologies; however, there is still a lack of data about the effects of administration of vitamin D in immune regulation in young asthmatic patients. In this study, we investigated its inhibitory effect on the immune response in young asthmatic patients and the possible mechanisms involved. Peripheral blood CD4(+) T cells from 10 asthmatic patients and 10 healthy controls were cultured under Th17 polarizing conditions in the presence or absence of [25(OH)D3], IL-17 cytokine production was determined by ELISA and flow cytometry. Messenger RNA (mRNA) expression of several factors related to Th17 cell function was determined by real-time PCR. The effect of [25(OH)D3]-treated dendritic cells (DCs) on CD4(+) T cell response was determined by ELISA and flow cytometry. Stimulation of naive CD4(+) T cells under Th17 polarizing conditions showed a higher Th17 cell differentiation in asthmatic patients than healthy controls. The addition of [25(OH)D3] significantly inhibited Th17 cell differentiation both in patients [P<0.001] and in normal controls [P=0.001] in a dose-dependent way. [25(OH)D3] was able to inhibit the gene expression of RORC, IL-17, IL-23R, and CCR6. [25(OH)D3]-treated DCs significantly inhibited IL-17 production [P=0.002] and decreased the percentage of CD4(+)IL-17(+) [P=0.007] in young asthmatics. The findings suggest that the inhibitory effect of [25(OH)D3] on the Th17 response was mediated via both T cells and DCs. DCs pathway is involved in the direct inhibition of 25(OH)D3 on Th17 cell differentiation in young asthmatics.

IL-17A and IL-17F genes variants and susceptibility to childhood asthma in Tunisia.

OBJECTIVES: IL-17A and IL-17F are new pro-inflammatory cytokines implicated in neutrophilic inflammation and thus, involved in the pathogenesis of asthma. We investigated the possible association among asthma and IL-17A -197G/A (rs2275913), IL-17F 7488A/G (rs763780) and IL-17F 7383A/G (rs2397084). METHODS: The study was performed in 171 patients with asthma (mean age 9.5 years, 105 boys, and 66 girls) and 171 healthy individuals matched with patients in age and sex. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used to detect genes' polymorphisms. RESULTS: IL-17A -197G/A and IL-17F 7383A/G were associated with asthma in children (p = 0.008, p = 0.001, respectively). No association was found with IL-17F 7488A/G polymorphism. Haplotype analysis revealed a significant association between GA and AG haplotypes and asthma (p = 0.004, p = 0.02). When patients were stratified according to the atopic status, no significant association was detected with any of the three studied variants. CONCLUSION: Our results suggested that SNPs in IL-17A and IL-17F confer susceptibility to childhood asthma in Tunisia.

Conservative management of postoperative bronchopleural fistulas.

OBJECTIVE: A bronchopleural fistula (BPF) is a serious complication after pulmonary resection and carries a high mortality rate. It remains a therapeutic challenge. The lack of a consensus suggests that no optimal therapy is available; however, endoscopic closure of a fistula may avoid extensive and potentially risky surgery. METHODS: Seventeen patients (15 men and 2 women) with a BPF after a pneumonectomy (n = 2) or a lobectomy (n = 15), seen between 1995 and 2010, were reviewed. Their median age was 50 years (range, 14-75 years). Underlying diseases were malignant (n = 4) and nonmalignant (n = 13). RESULTS: The mean interval between surgery and fistula development was 20 days (range, 5-270 days). Clinical symptoms leading to a diagnosis of BPF were a persistent air leak (n = 2), a persistent air leak associated with pleural empyema (n = 3), pleural empyema alone (n = 11), and dyspnea (n = 1). Mean fistula size was 3.3 mm (range, 2-9 mm). Treatment consisted of oriented pleural drainage, adequate antibiotic therapy, and endoscopic closure of the fistula with local application of silver nitrate through a flexible bronchoscope (3-15 sessions, 3 times per week). Fistula closure was successful in 16 patients, but failed in 1 patient, who died from acute respiratory distress. CONCLUSIONS: BPF is a severe complication in thoracic surgery. The combination of pleural drainage, adequate antibiotic treatment, and mucosal application of silver nitrate, through a flexible bronchoscope, is an efficient alternative and avoids extensive surgical intervention.

Induced sputum levels of IL-33 and soluble ST2 in young asthmatic children.

OBJECTIVE: Interleukin-33 is an IL-1 family cytokine which signals via its T1/ST2 receptor, and acts as a key regulator of inflammation, notably the type-2 response implicated in asthma. This study aims to measure the expression of soluble ST2 (sST2) and IL-33 in asthmatic children, depending on disease activity. METHODS: Thirty-seven children with well-defined asthma (20 moderate and 17 mild asthmatics) were studied. IL-33 and sST2 were measured by ELISA in serum and induced sputum (IS) samples, and compared with 22 age- and sex-matched healthy controls. Real-time quantitative PCR was used to determine IL-33 and TNF-α mRNA expression in IS. RESULTS: sST2 and IL-33 levels in IS and serum were significantly higher in patients compared with healthy controls (p = 0.0001). The increase in sST2 and IL33 was significantly more important in moderate cases than in mild asthma. A significant correlation was observed between serum and IS IL-33 levels (r = 0.497; p = 0.0018). Higher levels of IL-33 mRNA were detected in IS from asthmatics than those observed in controls. A significant correlation was found between TNF-α and IL-33 mRNA expression in the asthmatic subjects (r = 0.772, p = 0.0001). CONCLUSIONS: Values of sST2 and IL-33 observed in IS were found to correlate with disease activity. Elevated IL-33 mRNA expression in IS and its correlation with TNF-α reflected the inflammatory process observed in the lung of young asthmatics.

Pulmonary manifestations in Behçet disease: impaired natural killer cells activity.

BACKGROUND: Behçet's disease (BD) is a systemic vasculitis with unknown aetiology, where, besides genetic predisposition, an immune dysregulation involving T and B lymphocytes and hyperactive neutrophils contribute to disease pathogenesis. The aim of this study was to determine the cytotoxicity of natural killer (NK) cells in bronchoalveolar lavage (BAL) from BD patients with pulmonary manifestations. METHODS: BAL was performed in 27 patients with BD and pulmonary manifestations, 14 patients with Rheumatoid Arthritis (RA) and 23 healthy controls (HC). Related orphan receptor C (RORC) and forkheadbox P3 (FOXP3) mRNA transcript were determined in BAL by reverse transcription-polymerase chain reaction (RT-PCR). NK cells, NK cell cytotoxicity, and lymphokine-activated killer (LAK) activity against K562 cells were measured by flow cytometry. Proportions of NK precursors and expression of genes for IL-2 receptor ß (IL-2Rß; CD122), perforin, and granzyme in NK cells were measured by flow cytometry or RT-PCR. RESULTS: The analysis of transcription factors revealed an increase in the RORC/FOXP3 ratio (Th17/Treg cells) in BAL from BD patients. Percentages of NK were significantly lower in BD than in RA patients and healthy controls. Purified NK cells derived from BD patients were found to have lower cytotoxicity and LAK activity than those from controls. This defect of NK cells in BD patients was related to down-regulation of perforin and granzyme expression in NK cells. CONCLUSION: In BD patients, the increased RORC/FOXP3 ratio indicated an inflammatory state of the lung. NK cells were decreased together with an impairment of their activity due to a defective expression of granzyme and perforin. These abnormalities possibly contribute to immune system dysregulation found in BAL of BD patients with pulmonary manifestations.

Association of vitamin D receptor gene polymorphisms with susceptibility to asthma in Tunisian children: A case control study.

BACKGROUND: Vitamin D and its nuclear receptor (VDR) are linked to asthma in a genetic and immunologic basis. Polymorphisms in the VDR gene may alter the actions of vitamin D and then influence the development and the severity of asthma. AIMS: We aimed at elucidating the genetic association of VDR gene polymorphisms with susceptibility to asthma in Tunisian children and with serum vitamin D levels. METHODS: The study included 155 patients recruited from Abderrahmen MAMI hospital in Tunisia and two hundred twenty five healthy individuals matched with patients in age and sex for comparison. VDR genotypes were determined by PCR-RFLP method using endonuclease FokI, BsmI, TaqI and ApaI and vitamin D was assessed with a radioimmunoassay kit. RESULTS: The distribution of genotype frequencies differed significantly between asthmatics and controls (FokI: P=0.04; BsmI: P=0.006; TaqI: P=0.006). Haplotype analyses revealed a significant association between bAt and bat haplotypes and asthma (P=0.00076, P=0.016). When patients were stratified according to atopic status and stage of severity, no significant association was detected with VDR variants. No association was found between VDR SNPs and serum 25-hydroxyvitamin D levels. CONCLUSION: Our study shows a relation between VDR gene polymorphisms and susceptibility to asthma in children.

The impact of vitamin D deficiency on immune T cells in asthmatic children: a case-control study.

BACKGROUND: Vitamin D exerts profound effects on both adaptive and innate immune functions involved in the development and course of autoimmune and inflammatory diseases. As the incidence of vitamin D insufficiency is surprisingly high in the general population, experimental studies have started to investigate whether vitamin D levels (measured as serum 25 hydroxy vitamin D-25[OH]D) are correlated with immune cells and clinical parameters. PURPOSE: The aim of the present research was to investigate serum vitamin D status in a case-control study in children with asthma and to study associations between vitamin D levels and certain immunological parameters. MATERIALS AND METHODS: A case control study of thirty-nine children with clinically controlled asthma was enrolled to assess the relationship between serum vitamin D concentrations and disease activity. Vitamin D was assayed with a radioimmunoassay kit. We evaluated the relationship between vitamin D concentrations and forced vital capacity (FVC), forced expiratory volume in 1 second (FEV(1)), and the FEV(1)/FVC ratio. Correlations between inflammatory mediators, Th1, Th2, Th17, and regulatory T cells (Treg) and vitamin D were investigated. RESULTS: Only 15.38% of our asthmatic children had a sufficient serum 25(OH)D (≥30 ng/mL) whereas 80% of healthy children expressed sufficient levels. Deficient values of vitamin D (<20 ng/mL) were observed in 17 (43.59%) asthmatic patients (14.40 ± 3.30 ng/mL; P = 0.0001). Deficiency was not observed in controls. Th1/Th2 ratio was significantly correlated to 25(OH) D level (r = 0.698; P = 0.0001). A significant negative correlation was observed between serum interleukin-17 and vitamin D levels in young asthmatics (r = -0.617; P = 0.001). A significant correlation was observed between CD25(+)Foxp3(+) Treg cells and vitamin D values in asthmatics (r = 0.368; P = 0.021). CONCLUSION: Even in a southern Mediterranean country, hypovitaminosis D is frequent in children with asthma. Our findings suggest that vitamin D is an important promoter of T cell regulation in vivo in young asthmatics.