Host genetic variants associated with COVID-19 reconsidered in a Slovak cohort

We present the results of an association study involving hospitalized coronavirus disease 2019 (COVID-19) patients with a clinical background during the 3rd pandemic wave of COVID-19 in Slovakia. Seventeen single nucleotide variants (SNVs) in the eleven most relevant genes, according to the COVID-19 Host Genetics Initiative, were investigated. Our study confirms the validity of the influence of LZTFL1 and 2'-5'-oligoadenylate synthetase (OAS)1/OAS3 genetic variants on the severity of COVID-19. For two LZTFL1 SNVs in complete linkage disequilibrium, rs17713054 and rs73064425, the odds ratios of baseline allelic associations and logistic regressions (LR) adjusted for age and sex ranged in the four tested designs from 2.04 to 2.41 and from 2.05 to 3.98, respectively. The OAS1/OAS3 haplotype 'gttg' carrying a functional allele G of splice-acceptor variant rs10774671 manifested its protective function in the Delta pandemic wave. Significant baseline allelic associations of two DPP9 variants in all tested designs and two IFNAR2 variants in the Omicron pandemic wave were not confirmed by adjusted LR. Nevertheless, adjusted LR showed significant associations of NOTCH4 rs3131294 and TYK2 rs2304256 variants with severity of COVID-19. Hospitalized patients' reported comorbidities were not correlated with genetic variants, except for obesity, smoking (IFNAR2), and hypertension (NOTCH4). The results of our study suggest that host genetic variations have an impact on the severity and duration of acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Considering the differences in allelic associations between pandemic waves, they support the hypothesis that every new SARS-CoV-2 variant may modify the host immune response by reconfiguring involved pathways.

Complex analysis of the national Hereditary angioedema cohort in Slovakia - Identification of 12 novel variants in SERPING1 gene

Background

Hereditary angioedema (HAE) is a rare autosomal dominant genetic disease characterised by acute episodes of non-pruritic skin and submucosal swelling caused by increase in vascular permeability.

Objective

Here we present the first complex analysis of the National HAE Slovakian cohort with the detection of 12 previously un-published genetic variants in SERPING1 gene.

Methods

In patients diagnosed with hereditary angioedema caused by deficiency or dysfunction of C1 inhibitor (C1-INH-HAE) based on clinical manifestation and complement measurements, SERPING1 gene was tested by DNA sequencing (Sanger sequencing/massive parallel sequencing) and/or multiplex ligation-dependent probe amplification for detection of large rearrangements.

Results

The Slovakian national cohort consisted of 132 living patients with confirmed HAE. We identified 51 index cases (32 families, 19 sporadic patients/112 adults, 20 children). One hundred seventeen patients had HAE caused by deficiency of C1 inhibitor (C1-INH-HAE-1) and 15 patients had HAE caused by dysfunction of C1 inhibitor (C1-INH-HAE-2). The prevalence of HAE in Slovakia has recently been calculated to 1:41 280 which is higher than average calculated prevalence. The estimated incidence was 1:1360 000. Molecular-genetic testing of the SERPING1 gene found 22 unique causal variants in 26 index cases, including 12 previously undescribed and unreported.

Conclusion

The first complex report about epidemiology and genetics of the Slovakian national HAE cohort expands the knowledge of the C1-INH-HAE genetics. Twelve novel causal variants were present in the half of the index cases. A higher percentage of inframe variants comparing to other studies was observed. Heterozygous deletion of exon 3 found in a large C1-INH-HAE-1 family probably causes the dysregulation of the splicing isoforms balance and leads to the decrease of full-length C1-INH level.

Diagnostic tools for fecal incontinence: Scoring systems are the crucial first step

The main aim of this editorial is to comment on the recent article published by Garg et al in the World Journal of Gastroenterology 2023; 29: 4593-4603. This original research presents a new scoring system for fecal incontinence. Fecal incontinence is a chronic disease with a severe impact on the quality of life of the patients. Substantial social stigmatization often leads to significant underreporting of the condition even during visits to a specialist and could lead to further mismanagement or non-existent management of the disease. An important fact is that patients are often unable to describe their condition when not asked precisely defined questions. This problem is partially resolved by scoring questionnaires. Several scoring systems are commonly used; however, each of them has their shortcomings. For example, the absence of different kinds of leakage besides flatus and stool could further lead to underscoring the incontinence severity. Therefore, there has long been a call for a more precise scoring system. The correct identification of the presence and severity of fecal incontinence is paramount for further diagnostic approach and for choosing the appropriate therapy option. This editorial describes fecal incontinence, its effect on quality of life in general and further evaluates the diagnostic approach with a particular focus on symptom scoring systems and their implications for clinical practice.

Identification of a novel RPGR mutation associated with retinitis pigmentosa and primary ciliary dyskinesia in a Slovak family: a case report

Background

The mutations in the RPGR (retinitis pigmentosa GTPase regulator) gene are the most common cause of X-linked retinitis pigmentosa (XLRP), a rare genetic disorder affecting the photoreceptor cells in the retina. Several reported cases identified this gene as a genetic link between retinitis pigmentosa (RP) and primary ciliary dyskinesia (PCD), characterised by impaired ciliary function predominantly in the respiratory tract. Since different mutations in the same gene can result in various clinical manifestations, it is important to describe a correlation between the gene variant and the observed phenotype.

Methods

Two young brothers from a non-consanguineous Slovak family with diagnosed retinal dystrophy and recurrent respiratory infections were examined. Suspected PCD was diagnosed based on a PICADAR questionnaire, nasal nitric oxide analysis, transmission electron microscopy, high-speed video microscopy analysis, and genetic testing.

Results

We identified a novel frameshift RPGR mutation NM_001034853: c.309_310insA, p.Glu104Argfs*12, resulting in a complex X-linked phenotype combining PCD and RP. In our patients, this mutation was associated with normal ultrastructure of respiratory cilia, reduced ciliary epithelium, more aciliary respiratory epithelium, shorter cilia, and uncoordinated beating with a frequency at a lower limit of normal beating, explaining the clinical manifestation of PCD in our patients.

Conclusion

The identified novel pathogenic mutation in the RPGR gene expands the spectrum of genetic variants associated with the X-linked PCD phenotype overlapping with RP, highlighting the diversity of mutations contributing to the disorder. The described genotype-phenotype correlation can be useful in clinical practice to recognise a broader spectrum of PCD phenotypes as well as for future research focused on the genetic basis of PCD, gene interactions, the pathways implicated in PCD pathogenesis, and the role of RPGR protein for the proper functioning of cilia in various tissues throughout the body.

Pancreatic stiffness and anthropometric parameters in healthy volunteers

PURPOSE

The aim of this study was to define the values of percutaneous ultrasound shear-wave and strain elastography of the pancreas in healthy volunteers.

METHODS

This is a single-center prospective study conducted on volunteers who underwent examination of percutaneous point shear‑wave elastography and strain elastography. Both the shear-wave speed (Vs) and strain histogram were measured 3 times and median values were evaluated. Relevant recorded clinical data were age, sex, and height.

RESULTS

 From May 2020 to October 2021 a total of 90 patients (21 male, 69 female) were included in the study. Their average age was 26 years (from 22 to 65). The average SWM in kPa was 6.07 (2.58-17.29). The average value of SE was 134.44 (78.51-184.35). Most of the patients had BMI in the range of normal weight with an average value of 22.75 (17.5-28). The average depth of the localization of the pancreas was 4.5 cm. The effect of BMI on the strain histogram was significant (p < 0.05). We found a significant relationship between the strain histogram and the depth of localization of the pancreas (p < 0.01).

CONCLUSION

 We described normal values for pancreatic stiffness using ultrasound elastography by 2D-SWE and strain elastography. Our results indicate changes in values depending on BMI and depth of the pancreas. (Tab. 1, Fig. 5, Ref. 19).

Distal pancreatectomy

NTRODUCTION

Distal pancreatectomy is a standard surgical procedure for selected benign, premalignant, and malignant lesions localized in the pancreatic body or tail. Surgical resection remains the only curative option for patients diagnosed with adenocarcinoma of the pancreas.

PATIENTS AND METHODS

Perioperative and postoperative clinical courses were retrospectively assessed in patients, who underwent distal pancreatectomy during the 2011‒2021 period.

RESULTS

During the 2011‒2021 period, a total of 112 distal pancreatectomies were performed. 67 patients (59.8%) underwent laparoscopic distal pancreatectomy, and 45 patients (40.2%) open laparotomy. The conversion was necessary for 13 patients (11.6%). Distal pancreatectomies performed laparoscopically were associated more often with biochemical leak and the development of grade B fistula, on the other hand grade C fistula developed only in patients operated by open laparotomy (LPT). The mean operating time was slightly longer in the laparoscopic group (227.1 min vs 214.6 min). The mean estimated blood loss was significantly higher in the LPT group (540.4 ml vs 191.9 ml). The mean hospitalization time was slightly longer in the LPT group (11.8 days vs 9.3 days). The rates of early reoperations were comparable between both groups (6 vs 5).

CONCLUSION

Laparoscopic techniques are preferred in centers around the world to bring patients benefits by using a minimally invasive approach. These techniques are also preferred in our center, in nearly 60% of all distal pancreatectomies performed during 10 years, but on the other hand, there is a much more careful approach chosen in cases of malignant disease to achieve adequate radicality (Tab.4, Ref. 20).

The use of ketotifen as long-term anti-inflammatory prophylaxis in children with PFAPA syndrome

Introduction

Periodic fever, aphthous stomatitis, pharyngitis and adenitis syndrome (PFAPA) is the most frequent periodic fever syndrome in children. Its pathogenesis is still unknown, but some disease-modifying factors were observed. Several medications were tested for the long-term prophylaxis of inflammatory flares; however, none are standardly used.

Methods

This prospective clinical trial enrolled 142 children (71 girls, 50%) meeting diagnostic criteria for PFAPA syndrome. We analysed selected clinical characteristics and compared laboratory parameters during the flare and attack-free period (at least two weeks after the attack). Moreover, we assessed the possible therapeutic effect of ketotifen on the duration of attack free-periods and clinical picture.

Results

The mean age of patients was 6.81 ± 3.03 years and the mean age of onset of symptoms was 2.31 ± 2.02 years. No significant differences were observed between genders.We recorded a positive family history for PFAPA in 31.69% of patients. Attacks lasted for 2.8 ± 1.2 days, with intervals between attacks of 4 ± 1 weeks. We administered ketotifen in 111 (77.8%) patients, and a positive effect was observed in 86 (77.5%) of patients. We observed prolonged attack-free intervals in patients treated with ketotifen (14.7 ± 8.9 days in comparison with 4.4 ± 1.9 days before the treatment; p<0.001). The used dose of ketotifen was 0.08 ± 0.01 mg/kg/day. Mild side effects were observed in four patients (restlessness, irritability, agitation and constipation).

Discussion

Our data supports the use of ketotifen for long-term prophylaxis in children with PFAPA syndrome with positive effects on the attenuation of disease activity and the prolongation of attack-free periods. Further well-designed studies should confirm the preliminary data.

Dysfunctional mucociliary clearance in asthma and airway remodeling - New insights into an old topic

Bronchial asthma is a heterogeneous respiratory condition characterized by chronic airway inflammation, airway hyperresponsiveness and airway structural changes (known as remodeling). The clinical symptoms can be evoked by (non)specific triggers, and their intensity varies over time. In the past, treatment was mainly focusing on symptoms' alleviation; in contrast modern treatment strategies target the underlying inflammation, even during asymptomatic periods. Components of airway remodeling include epithelial cell shedding and dysfunction, goblet cell hyperplasia, subepithelial matrix protein deposition, fibrosis, neoangiogenesis, airway smooth muscle cell hypertrophy and hyperplasia. Among the other important, and frequently forgotten aspects of airway remodeling, also loss of epithelial barrier integrity, immune defects in anti-infectious defence and mucociliary clearance (MCC) dysfunction should be pointed out. Mucociliary clearance represents one of the most important defence airway mechanisms. Several studies in asthmatics demonstrated various dysfunctions in MCC - e.g., ciliated cells displaying intracellular disorientation, abnormal cilia and cytoplasmic blebs. Moreover, excessive mucus production and persistent cough are one of the well-recognized features of severe asthma and are also associated with defects in MCC. Damaged airway epithelium and impaired function of the ciliary cells leads to MCC dysfunction resulting in higher susceptibility to infection and inflammation. Therefore, new strategies aimed on restoring the remodeling changes and MCC dysfunction could present a new therapeutic approach for the management of asthma and other chronic respiratory diseases.

Acute-on-chronic liver failure in patients with severe acute respiratory syndrome coronavirus 2 infection

The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has had a significant impact on the lives of millions of people, especially those with other concomitant diseases, such as chronic liver diseases. To date, seven coronaviruses have been identified to infect humans. The main site of pathological action of these viruses is lung tissue. However, a substantial number of studies have proven that SARS-CoV-2 shows affinity towards several organs, including the gastrointestinal tract and the liver. The current state of evidence points to several proposed mechanisms of liver injury in patients with COVID-19 and their combination. Liver impairment is considered to be the result of the direct effect of the virus on the hepatic tissue cells, a systemic reaction consisting of inflammation, hypoxia and cytokine storm, drug-induced liver injury, with the possible contribution of a perturbed gut-liver axis. Reactivation of chronic hepatic disease could be another factor for liver impairment in patients with SARS-CoV-2 infection. Acute-on-chronic liver failure (ACLF) is a relatively new syndrome that occurs in 10%–30% of all hospitalized patients with chronic liver disease. It is crucial to recognize high-risk patients due to the increased morbidity and mortality in these cases. Several published studies have reported virus infection as a trigger factor for ACLF. However, to date, there are few relevant studies describing the presence of ACLF in patients with acute SARS-CoV-2 infection. In this minireview we summarize the current state of knowledge regarding the relation between ACLF and acute SARS-CoV-2 infection.

Persistence of Metabolomic Changes in Patients during Post-COVID Phase: A Prospective, Observational Study

Several relatively recently published studies have shown changes in plasma metabolites in various viral diseases such as Zika, Dengue, RSV or SARS-CoV-1. The aim of this study was to analyze the metabolome profile of patients during acute COVID-19 approximately one month after the acute infection and to compare these results with healthy (SARS-CoV-2-negative) controls. The metabolome analysis was performed by NMR spectroscopy from the peripheral blood of patients and controls. The blood samples were collected on 3 different occasions (at admission, during hospitalization and on control visit after discharge from the hospital). When comparing sample groups (based on the date of acquisition) to controls, there is an indicative shift in metabolomics features based on the time passed after the first sample was taken towards controls. Based on the random forest algorithm, there is a strong discriminatory predictive value between controls and different sample groups (AUC equals 1 for controls versus samples taken at admission, Mathew correlation coefficient equals 1). Significant metabolomic changes persist in patients more than a month after acute SARS-CoV-2 infection. The random forest algorithm shows very strong discrimination (almost ideal) when comparing metabolite levels of patients in two various stages of disease and during the recovery period compared to SARS-CoV-2-negative controls.

A machine learning approach for identification of gastrointestinal predictors for the risk of COVID-19 related hospitalization

Background and aim

COVID-19 can be presented with various gastrointestinal symptoms. Shortly after the pandemic outbreak, several machine learning algorithms were implemented to assess new diagnostic and therapeutic methods for this disease. The aim of this study is to assess gastrointestinal and liver-related predictive factors for SARS-CoV-2 associated risk of hospitalization.

Methods

Data collection was based on a questionnaire from the COVID-19 outpatient test center and from the emergency department at the University Hospital in combination with the data from internal hospital information system and from a mobile application used for telemedicine follow-up of patients. For statistical analysis SARS-CoV-2 negative patients were considered as controls in three different SARS-CoV-2 positive patient groups (divided based on severity of the disease). The data were visualized and analyzed in R version 4.0.5. The Chi-squared or Fisher test was applied to test the null hypothesis of independence between the factors followed, where appropriate, by the multiple comparisons with the Benjamini Hochberg adjustment. The null hypothesis of the equality of the population medians of a continuous variable was tested by the Kruskal Wallis test, followed by the Dunn multiple comparisons test. In order to assess predictive power of the gastrointestinal parameters and other measured variables for predicting an outcome of the patient group the Random Forest machine learning algorithm was trained on the data. The predictive ability was quantified by the ROC curve, constructed from the Out-of-Bag data. Matthews correlation coefficient was used as a one-number summary of the quality of binary classification. The importance of the predictors was measured using the Variable Importance. A 2D representation of the data was obtained by means of Principal Component Analysis for mixed type of data. Findings with the p-value below 0.05 were considered statistically significant.

Results

A total of 710 patients were enrolled in the study. The presence of diarrhea and nausea was significantly higher in the emergency department group than in the COVID-19 outpatient test center. Among liver enzymes only aspartate transaminase (AST) has been significantly elevated in the hospitalized group compared to patients discharged home. Based on the Random Forest algorithm, AST has been identified as the most important predictor followed by age or diabetes mellitus. Diarrhea and bloating have also predictive importance, although much lower than AST.

Conclusion

SARS-CoV-2 positivity is connected with isolated AST elevation and the level is linked with the severity of the disease. Furthermore, using the machine learning Random Forest algorithm, we have identified the elevated AST as the most important predictor for COVID-19 related hospitalizations.

Phenomenon of hypoglycemia unawareness in patients with insulinoma - single center experience

INTRODUCTION

Insulinomas are rare neuroendocrine tumors of pancreas. Clinical manifestations include various symptoms of hypoglycemia, which is the result of insulin overproduction. Symptoms of hypoglycemia are heterogenous what most probably contributes to diagnostic delay. In this study we retrospectively evaluated clinical features of hypoglycemia. We discovered that a substantial number of patients suffered from hypoglycemia unawareness.

MATERIALS AND METHODS

We performed retrospective analysis of prospectively collected patients with histologically confirmed insulinoma. We evaluated clinical features and signs of hypoglycemia and the duration of symptoms and performed thorough review of the patients' files in order to identify whether patients had been falsely diagnosed previously. Each patient underwent 72 hour fasting test during which levels of immunoreactive insulin (IRI), C-peptide and nadir blood glucose level were obtained. Based on the clinical findings and results of 72 hour fasting test we identified a subgroup of patients with hypoglycemia unawareness. These had an episode of clinically silent hypoglycemia. We compared IRI and C-peptide levels obtained at the time of the fasting test termination in the unawareness group and the group without hypoglycemia unawareness.

RESULTS

Twenty two patients with insulinoma that had been hospitalized in our tertiary center were included in the analysis. Mean age was 51±16.7 years. The most common symptom reported by 63.6% of patients was fatigue, followed by increased appetite with consequent weight gain and the loss of consciousness, both reported by 40.9% of patients. Based on the review of clinical features and the results of the fasting test we identified a group of patients with hypoglycemia unawareness. We labeled the patient accordingly in case of the loss of consciousness in personal history as well as asymptomatic hypoglycemia or severe neuroglycopenic symptoms during the fasting test without any accompanying or preceding clinical signs. There were 7 patients with hypoglycemia unawareness in our cohort (31.8%). Patients with this phenomenon had significantly lower levels of both IRI (2.35±1.25 vs. 5.88±3.92ng/ml, p=0.01) and C-peptide (9.14±7.36 vs. 50±42.8 µU/ml, p=0.01) than the rest of the patients. Nadir blood glucose level during the fasting test showed no significant difference (9.4±8.2 vs. 12.2±8.2 months, p=0.28) in the unawareness group and the rest of the patients, respectively.

CONCLUSION

We described the phenomenon of unawareness to hypoglycemia in the patients with insulinoma. This has not been recognized in insulinoma patients yet since available evidence mostly relates to type I diabetic patients. It might lead to higher morbidity and diagnostic delay. Further studies with prospective evaluation should be performed to further confirm relatively high prevalence in patients with insulinoma.

COVID-19 and the differences in physiological background between children and adults and their clinical consequences

The SARS-CoV-2 pandemic has indeed been one of the most significant problems facing the world in the last decade. It has affected (directly or indirectly) the entire population and all age groups. Children have accounted for 1.7 % to 2 % of the diagnosed cases of COVID-19. COVID-19 in children is usually associated with a mild course of the disease and a better survival rate than in adults. In this review, we investigate the different mechanisms which underlie this observation. Generally, we can say that the innate immune response of children is strong because they have a trained immunity, allowing the early control of infection at the site of entry. Suppressed adaptive immunity and a dysfunctional innate immune response is seen in adult patients with severe infections but not in children. This may relate to immunosenescence in the elderly. Another proposed factor is the different receptors for SARS-CoV-2 and their differences in expression between these age groups. In infants and toddlers, effective immune response to viral particles can be modulated by the pre-existing non-specific effect of live attenuated vaccines on innate immunity and vitamin D prophylaxis. However, all the proposed mechanisms require verification in larger cohorts of patients. Our knowledge about SARS-CoV-2 is still developing.

Sensenbrenner Syndrome Presenting with Severe Anorexia, Failure to Thrive, Chronic Kidney Disease and Angel-Shaped Middle Phalanges in Two Siblings

Sensenbrenner syndrome is a very rare autosomal recessive disorder caused by variants in genes involved in the functional development of primary cilia. Typical clinical manifestations include craniofacial and skeletal abnormalities, hence the alternative name cranioectodermal dysplasia. Chronic kidney disease due to progressive tubulointerstitial nephritis (nephronophthisis) has been described in these patients. The authors present 2siblings with severe anorexia, failure to thrive, chronic kidney disease, and angel-shaped middle phalanges. Two previously described variants p.(Leu641*) and p.(Asp841Val) were identified in the WDR35 gene which is most commonly affected in this condition. Analysis of all coding exons of the GDF5 gene was normal. This is the first report of Sensenbrenner syndrome presenting with severe anorexia and failure to thrive at early age. Angel-shaped middle phalanges in the absence of the GDF5 variant may represent an overlapping phenotypic manifestation of ciliopathy.

Young and exhausted

Chronic Fatigue Syndrome (CFS), also known as myalgic encephalomyelitis (ME), is a complicated disease characterized by extreme fatigue of at least six months duration. It is necessary to rule out the organic cause of CFS in the pediatric patient in order not to overlook the preventable or the treatable condition. In our case report we present a case of a patient with a surprising origin OF CFS/ME diagnosed by cardiopulmonary exercise testing.

A novel SPINK5 mutation and successful subcutaneous immunoglobulin replacement therapy in a child with Netherton syndrome

We report a 2-year-old patient with Netherton syndrome presenting with generalized exfoliative erythroderma, ichthyosiform dermatitis, trichorrhexis invaginata, hypernatremic dehydration, failure to thrive, and recurrent respiratory infections. Molecular analysis of SPINK5 identified a novel mutation (c.1530CA). Our case report also verifies and supports the safety and efficacy of subcutaneous immunoglobulin substitution in chronic generalized skin disorders associated with primary immunodeficiencies such as Netherton syndrome.

USB capsule endoscope for retrograde imaging of the esophagus

SIGNIFICANCE

Endoscopes represent electro-optical devices that are used to visualize internal body cavities. The specialized endoscopic procedure of the upper gastrointestinal tract from the esophagus down to the duodenum is called an esophagogastroduodenoscopy.

AIM

We bring our newly developed capsule endoscopy device as a promising alternative diagnostic method for visualization of the upper gastrointestinal tract.

APPROACH

Capsule endoscopy has become an attractive method that uses a tiny wireless camera to take pictures of the digestive tract. Existing esophageal capsule endoscopy does not allow a retrograde view of the esophagus while retrograde scanning can provide information on the esophageal pathology.

RESULTS

In comparison to the existing esophageal capsule endoscopy, our system is much simpler and cheaper due to the need for fewer electronic devices. Moreover, its use is not limited by the capacity of the batteries used by existing capsule endoscopes. The new esophageal endoscopic system was created by combining the universal serial bus (USB) endoscope module with the thin power wires that are routed through the USB port to the computer.

CONCLUSIONS

The endoscope was tested on a volunteer without any side effects such as nausea, belching, and general discomfort. The examination of the patient is performed in a sitting position and the patient discomfort during the examination is minimal so it can be performed without anesthesia.

Immune Parameters and COVID-19 Infection - Associations With Clinical Severity and Disease Prognosis

Severe acute respiratory syndrome caused by a novel 2019 coronavirus (SARS-CoV2) represents one of the most studied infectious diseases of today. The number of scientific reports and publications increases exponentially day by day. While the majority of infected subjects are asymptomatic or show mild symptoms, there is an important proportion of patients who requires hospitalization and, sometimes, intensive care. Immune response to novel coronavirus is complex, involves both innate and adaptive immunity, and is biphasic. Significant differences were observed when comparing severe and non-severe patients. Analysis of the reported results from clinical trials clearly show an involvement of specific cellular immunity (predominantly leucopenia, decreased counts of CD3+, CD4+, and CD8+ T lymphocytes, changes of T cell compartment) and the so-called cytokine storm, which is associated with worsening of symptoms and the promotion of lung damage. An interesting finding regarding eosinopenia that can have both diagnostic and prognostic value is reported by some authors. Examination of selected immune parameters could help to identify severe patients with the risk of unfavorable course of the disease, predict the prognosis and recognize improvement in the clinical status. Moreover, detailed analysis of the immune changes could help to select novel prospective therapeutic strategies.

Ciliary beat frequency in children with adenoid hypertrophy

BACKGROUND

Children with adenoid hypertrophy (AH) have impaired respiratory system defense mechanisms, such as mucociliary clearance. We hypothesized that AH negatively affects one of the most important aspects of mucociliary clearance-ciliary beat frequency (CBF) and that adenoidectomy could potentially restore this essential defence mechanism of the airways. This study evaluated the influence of AH and endoscopic adenoidectomy on the CBF of the nasal respiratory epithelium in children.

METHODS

This prospective study included 64 children with confirmed AH aged 3 to 18 years and 43 age- and sex-matched healthy controls. Nasal CBF was analyzed using a digital high-speed video microscope and the software application Ciliary Analysis (NI LabVIEW). The preoperative adenoid size was assessed according to Cassano. Clinical symptoms of chronic rhinosinusitis were evaluated using the SNOT-20 questionnaire.

RESULTS

Children with AH had a median CBF of 5.35 ± 1.06 Hz. Six months after surgery, the median CBF was significantly higher (6.48 ± 0.88 Hz; P < .001) and reached the values of healthy children (6.37 ± 0.71 Hz; P = .512). The size of the adenoid tissue did not correlate with the CBF. No influence of age or gender on the CBF was found. After adenoidectomy, a significant reduction of the mean total SNOT-20 score was recorded (P < .01).

CONCLUSION

Children with clinically symptomatic AH have impaired mucociliary clearance due to decreased nasal CBF. Removal of hypertrophic adenoid tissue normalizes the CBF and reduces the presence of clinical symptoms of rhinosinusitis.

Comprehensive analysis of acidic pharyngeal reflux before and after proton pump inhibitor treatment in patients with suspected laryngopharyngeal reflux

OBJECTIVES

The usefulness of pharyngeal pH monitoring in patients with symptoms attributed to laryngopharyngeal reflux (LPR) has been questioned. One problem is the uncertainty whether the pharyngeal pH monitoring captures the aspects of LPR which are responsible for symptoms. We aimed to gain more insight into this problem by performing a comprehensive analysis of acidic pharyngeal reflux before and after the treatment with proton pump inhibitors (PPIs) in patients with suspected LPR.

METHODS

We used simultaneous pharyngeal and distal esophageal 24-hour pH/impedance monitoring to establish the gastroesophageal origin of pharyngeal reflux, and an unbiased approach to analysis by evaluating a whole range of pharyngeal reflux acidity (pH < 6, pH < 5.5, pH < 5.0, pH < 4.5 and pH < 4.0).

RESULTS

PPI treatment substantially (by ~50%) improved the symptoms attributed to LPR. In contrast, PPI did not reduce the number of pharyngeal reflux episodes or duration of pharyngeal acid exposure at any pH level. This was also true in a subgroup of patients considered to be good responders to PPI (symptoms improvement by ~75%). Furthermore, good responders did not have more acidic pharyngeal reflux than the patients who were less responsive to PPI.

CONCLUSIONS

PPI treatment did not reduce acidic pharyngeal reflux despite substantially improving the symptoms attributed to LPR. This may be because pharyngeal pH monitoring does not quantitatively capture the aspects of LPR responsible for symptoms or because acid causes the symptoms also by mechanisms other than LPR. Our results argue against the utility of pharyngeal pH monitoring in patients with suspected LPR.

The infusion of menthol into the esophagus evokes cold sensations in healthy subjects but induces heartburn in patients with gastroesophageal reflux disease (GERD)

Recent studies in animal models have reported that some afferent fibers innervating the esophagus express the cold receptor TRPM8. In the somatosensory system the stimulation of TRPM8 leads to cold sensations and in certain circumstances alleviates pain. It is therefore hypothesized in this paper that the esophageal infusion of the TRPM8 activator menthol evokes cold sensations from the esophagus and alleviates heartburn in humans. The esophageal infusion of menthol (3 mM, 20 min) evoked cold sensations in 11 of 12 healthy subjects. In striking contrast, the esophageal infusion of menthol evoked heartburn in 10 of 10 patients with gastroesophageal reflux disease (GERD). In healthy subjects the cold sensation evoked by menthol was perceived only as a minor discomfort as evaluated by the visual analog scale (VAS score 1.9 ± 0.3 on the scale 1-10). However, in patients with GERD the menthol-induced heartburn was perceived as painful (VAS score 5.6 ± 0.6, P < 0.01 compared to healthy subjects). It is concluded that the sensations evoked by esophageal infusion of menthol change from relatively nonpainful cold sensations in healthy subjects to painful heartburn sensations in patients with GERD. These qualitative and quantitative changes indicate substantial alterations in afferent signaling mediating sensations from the esophagus in patients with GERD.

Acidic Pharyngeal Reflux Does Not Correlate with Symptoms and Laryngeal Injury Attributed to Laryngopharyngeal Reflux

BACKGROUND

Laryngopharyngeal reflux (LPR) is suspected when the symptoms are attributed to the penetration of acidic gastroesophageal reflux (GER) into the larynx. However, the relationships between the intensity of LPR and symptoms and laryngeal injury have not been elucidated. Several factors confound the study of LPR, namely pH is monitored in the pharynx (pharyngeal reflux) but the pharyngeal acidity (pH) required to induce laryngeal injury is unknown, the GER origin of pharyngeal acid is not always established, and a recent treatment with proton pump inhibitors (PPI) confounds the analysis.

AIMS

We aimed to limit these confounding factors to analyze the relationship between LPR and symptoms and laryngeal injury.

METHODS

We used dual pharyngeal and distal esophageal 24-h pH/impedance monitoring to establish GER origin of pharyngeal reflux, we used an unbiased approach to analysis by evaluating a whole range of acidity (pH < 6, pH < 5.5, pH < 5.0, pH < 4.5 and pH < 4.0) in patients with suspected LPR without PPI for  > 30 days.

RESULTS

Pharyngeal reflux was (median[IQR]) 14[8-20.5] and 4[1.5-6.5] pharyngeal reflux episodes with pH < 6.0 and pH < 5.5, respectively. Pharyngeal reflux with pH < 5.0 was rare. Comprehensive analysis did not reveal any correlation between symptoms (reflux symptom index) or laryngeal injury (reflux finding score) and the number of pharyngeal reflux episodes or duration of pharyngeal acid exposure at any pH level.

CONCLUSION

Unbiased comprehensive approach did not reveal any relationship between acidic pharyngeal reflux and the symptoms or laryngeal injury attributed to LPR. Limited clinical usefulness of pharyngeal monitoring reported by others is unlikely due to confounding factors.

Idiopathic Pan-Colonic and Small-Intestine Varices

Idiopathic colonic varices represent a rare source of gastrointestinal haemorrhage with a presumed incidence around 0.0007%. Herein, we present a case of idiopathic colonic and small-intestine varices. According to our knowledge, this case report is the first description of both pan-colonic and small-intestine idiopathic varices of this extent. A young male patient without any previous notable medical history was admitted to the hospital because of massive enterorrhagia with haemodynamic instability. Colonoscopy revealed massive pan-colonic varices. After stabilization, numerous diagnostic procedures were performed in order to investigate the aetiology of pan-colonic varices without any explanation of the patient's condition. In addition, capsule endoscopy revealed varices through the whole length of the small intestine. The final diagnosis was idiopathic varices of the colon and small intestine. Because of the rapid clinical stabilization, the single incident of haemorrhage and the extension of the disease, a conservative approach was chosen (venotonics and β-blockers). During the 12-month follow-up period, the patient reported no gastrointestinal haemorrhage.

Canakinumab as monotherapy for treatment of familial Mediterranean fever - first report in Central and Eastern Europe region

Autoinflammatory disorders (AID) are characterized by spontaneous attacks of acute inflammation with a broad spectrum of clinical symptoms. Ongoing inflammation and reoccurrence of acute flares can lead to the development of amyloidosis. One group of AID is represented by monogenic periodic fever syndromes while familial Mediterranean fever (FMF) is the most common form of AID from this group. Its prevalence in Central and Eastern Europe was reported to be very low. We report a case of FMF patient with a very severe clinical course of FMF and intolerance to colchicine, which is a gold standard for FMF treatment. The clinical effect of the application of anakinra was insufficient and accompanied with side effects and low tolerability. Switching to canakinumab (human monoclonal antibody against IL-1β) at dose of 150 mg every 4 weeks induced a rapid remission of the disease activity and inflammatory markers. However, due to relapse of acute flares after three weeks from application, the escalation of dose to 300 mg every 4 weeks induced a complete remission of symptoms and significantly improved the quality of life. This is the first report of successful canakinumab administration in FMF patient in Central and Eastern Europe, a region with very low incidence of FMF (Tab. 1, Ref. 16).

Association of Polymorphisms in CYBA, SOD1, and CAT Genes with Type 1 Diabetes and Diabetic Peripheral Neuropathy in Children and Adolescents

AIMS

The aim of our study was to investigate possible associations between three SNPs: rs4673 in the CYBA gene; rs1041740 in the SOD1 gene; and rs1001179 in the CAT gene, and type 1 diabetes (T1D) or diabetic peripheral neuropathy (DPN) in T1D patients.

MATERIALS AND METHODS

Allelic variants of the selected SNPs were determined by allelic discrimination assays in 114 T1D patients enrolled in the study group and in 90 healthy individuals from a control group. Associations between each of the three SNPs were tested in subgroups of T1D patients divided according to the presence of DPN.

RESULTS

The TT genotype of rs4673 in the CYBA gene was associated with DPN in T1D patients (OR 4.997, 95% CI 1.403-19.083, p = 0.016). Weak significance was observed for a protective effect of the TT genotype of rs1041740 in the SOD1 gene relative to T1D development (OR 0.318, 95% CI 0.092-0.959, p = 0.056). There was no significant association between the CAT gene SNP rs1001179 and T1D or DPN.

CONCLUSION

We showed a strong association of the CYBA polymorphism rs4673 with DPN in Slovak children and adolescents with T1D. Further studies are necessary to assess the relationship between rs1041740 and T1D or DPN.

Short-term metabolic control and sleep in children and adolescents with type 1 diabetes mellitus

AIMS

The aim of this study was to examine sleep in T1D children and in healthy controls by polysomnographic (PSG) examination and to determine the influence of short-term metabolic compensation on sleep quality and sleep disordered breathing (SDB).

METHODS

The prospective cross-sectional study included 44 T1D subjects and 60 healthy controls, aged 10-19 years. Subjects underwent anthropometric measurements, laboratory testing and standard overnight in-laboratory video polysomnography with continuous glucose monitoring (CGM).

RESULTS

No significant differences were found in total sleep time, sleep efficiency, percentage of sleep stages and respiratory parameters between T1D and healthy group. T1D children with more optimal short-term metabolic control (AvgSG < 10 mmol/l, n = 18) had a significantly lower apnea-hypopnea index (AHI) (0.3(0-0.5) vs. 0.6 (0.2-0.9) events/h, p < 0.05)and respiratory arousal index (0(0-0,1) vs. 0.2(0-0.3)), p < 0.01) compared to children with suboptimal short-term control(n = 26), no significant differences were found in parameters of sleep architecture. Obstructive sleep apnea (OSA) was diagnosed in only one T1D patient, nine T1D children had mild central apnea.

CONCLUSIONS

There may be an association between short-term metabolic compensation and SDB in T1D children without chronic complications, obesity or overweight and hypoglycemia. Further research is needed to confirm this result.

Sleep Architecture in Children With Common Phenotype of Obstructive Sleep Apnea

STUDY OBJECTIVES

In children, the effect of the common phenotype of obstructive sleep apnea (OSA) on sleep architecture is not adequately documented. The aim of this study was to evaluate sleep architecture in a pediatric population with the common phenotype of OSA.

METHODS

The prospective cross-sectional study included 116 children in the age range of 3 to 8 years with suspected OSA and 51 healthy children. All children underwent standard overnight in-laboratory video polysomnography. Patients with obstructive apnea-hypopnea index ≥ 1, adenotonsillar hypertrophy, a long face, narrow palate or minor malocclusions, and no obesity were defined as a common phenotype. Polysomnographic parameters of sleep architecture and sleep clinical record were statistically analyzed according to OSA and its severity.

RESULTS

In total, 94 pediatric patients (59.60% male) received the diagnosis of the common phenotype of OSA (mean age of 5.25 ± 1.39 years). A lower percentage of stage N3 sleep (27.70 ± 3.76% versus 31.02 ± 4.23%; P < .05), a greater percentage of stage N1 sleep (8.40 ± 3.98% versus 2.68 ± 3.02%, P < .01), reduced deep sleep efficiency (46.01 ± 4.98% versus 50.25 ± 3.72%; P < .05) and longer sleep latency (18.40 ± 8.48 minutes versus 9.90 ± 11.55 minutes, P < .01) were found in children with the common phenotype of OSA compared with healthy controls. No significant differences were found in total sleep time, sleep efficiency, and percentage of stage R sleep and stage N2 sleep between groups and in sleep stage distribution and cyclization.

CONCLUSIONS

These findings suggest that the most common phenotype of pediatric OSA has a negative effect on the structure of sleep, but other clinical studies are needed to confirm this result.

Airway Defense Control Mediated via Voltage-Gated Sodium Channels

Expression of voltage-gated sodium channels (Nav) takes place in the airways and the role of Nav1.7 and Nav1.8 in the control of airway's defense reflexes has been confirmed. The activation of Nav channels is crucial for cough initiation and airway smooth muscle reactivity, but it is unknown whether these channels regulate ciliary beating. This study evaluated the involvement of Nav1.7 and Nav1.8 channels in the airway defense mechanisms using their pharmacological blockers in healthy guinea pigs and in the experimental allergic asthma model. Asthma was modeled by ovalbumin sensitization over a period of 21 days. Blockade of Nav1.7 channels significantly decreased airway smooth muscle reactivity in vivo, the number of cough efforts, and the cilia beat frequency in healthy animals. In the allergic asthma model, blockade of Nav1.8 efficiently relieved symptoms of asthma, without adversely affecting cilia beat frequency. The study demonstrates that Nav1.8 channel antagonism has a potential to alleviate cough and bronchial hyperreactivity in asthma.

The Role of Ion Channels to Regulate Airway Ciliary Beat Frequency During Allergic Inflammation

Overproduction of mucus is a hallmark of asthma. The aim of this study was to identify potentially effective therapies for removing excess mucus. The role of voltage-gated (Kir 6.1, KCa 1.1) and store-operated ion channels (SOC, CRAC) in respiratory cilia, relating to the tracheal ciliary beat frequency (CBF), was compared under the physiological and allergic airway conditions. Ex vivo experiments were designed to test the local effects of Kir 6.1, KCa 1.1 and CRAC ion channel modulators in a concentration-dependent manner on the CBF. Cilia, obtained with the brushing method, were monitored by a high-speed video camera and analyzed with ciliary analysis software. In natural conditions, a Kir 6.1 opener accelerated CBF, while CRAC blocker slowed it in a concentration-dependent manner. In allergic inflammation, the effect of Kir 6.1 opener was insignificant, with a tendency to decrease CBF. A cilio-inhibitory effect of a CRAC blocker, while gently reduced by allergic inflammation, remained significant. A KCa 1.1 opener turned out to significantly enhance the CBF under the allergic OVA-sensitized conditions. We conclude that optimally attuned concentration of KCa 1.1 openers or special types of bimodal SOC channel blockers, potentially given by inhalation, might benefit asthma.

Two novel RFX6 variants in siblings with Mitchell-Riley syndrome with later diabetes onset and heterotopic gastric mucosa

Mitchell-Riley syndrome, an autosomal recessive disorder caused by mutations in the RFX6 gene, is defined as a combination of neonatal diabetes mellitus and serious congenital gastrointestinal defects. We describe Mitchell-Riley syndrome in two sisters with two novel compound heterozygous variants in the RFX6 gene: c.1154G > A, p.(Arg385Gln), and c.1316_1319delTCTA, p.(Ile439Thrfs*13). Both sisters present milder forms of the syndrome, likely due to possible residual activity of the p.Arg385Gln variant, which is localized in a dimerization domain of the RFX6 transcription factor. We propose that the prognosis is dependent on patient RFX6 genotype and possible residual activity of RFX6 transcription factor. Both sisters had atypical later onset of diabetes, at 2 years and 10 months and 2 years and 7 months, respectively. This supports the need of extending the definition of diabetes in Mitchell-Riley syndrome from neonatal to childhood onset and regular glyceamia check in patients with gastrointestinal tract malformations typical for Mitchell-Riley syndrome. The clinical course in both sisters improved significantly after surgical removal of parts of the small intestine with heterotopic gastric mucosa. We suggest that gastric mucosa heterotopy is an important actionable part of Mitchell-Riley syndrome and could have been responsible for the malabsorption, failure to thrive and severe anemia present in previously reported patients with Mitchell-Riley syndrome.

Studies on the regulation of transient lower esophageal sphincter relaxations (TLESRs) by acid in the esophagus and stomach

Transient lower esophageal sphincter relaxation (TLESR) is the major mechanism of gastroesophageal reflux, but the regulation of TLESR by stimuli in the esophagus is incompletely understood. We have recently reported that acid infusion in the esophagus substantially (by 75%) increased the number of meal-induced TLESR in healthy subjects. We concluded that the TLESR reflex triggered by gastric distention with meal was enhanced by the stimulation of esophageal nerves by acid. However, the possibilities that the acid infused into the esophagus acts after passing though lower esophageal sphincter in stomach to enhance TLESR, or that the acid directly initiates TLESR from the esophagus were not addressed. Here, we evaluated the effect of acid infusion into the proximal stomach on meal-induced TLESR (study 1) and the ability of acid infusion into the esophagus to initiate TLESR without prior meal (study 2). We analyzed TLESRs by using high-resolution manometry in healthy subjects in paired randomized studies. In study 1, we found that acid infusion into the proximal stomach did not affect TLESRs induced by standard meal. The number of meal-induced TLESRs following the acid infusion into the proximal stomach was similar to the number of meal-induced TLESRs following the control infusion. In study 2, we found that acid infusion into the esophagus without prior meal did not initiate TLESRs. We conclude that the increase in the meal-induced TLESRs by acid in the esophagus demonstrated in our previous study is not attributable to the action of acid in the stomach or to direct initiation of TLESR from the esophagus by acid. Our studies are consistent with the concept that the stimuli in the esophagus can influence TLESRs. The enhancement of TLESR by acid in the esophagus may contribute to pathogenesis of gastroesophageal reflux in some patients.

Beta-palmitate - a natural component of human milk in supplemental milk formulas

The composition and function of human milk is unique and gives a basis for the development of modern artificial milk formulas that can provide an appropriate substitute for non-breastfed infants. Although human milk is not fully substitutable, modern milk formulas are attempting to mimic human milk and partially substitute its complex biological positive effects on infants. Besides the immunomodulatory factors from human milk, research has been focused on the composition and structure of human milk fat with a high content of β-palmitic acid (sn-2 palmitic acid, β-palmitate). According to the available studies, increasing the content of β-palmitate added to milk formulas promotes several beneficial physiological functions. β-palmitate positively influences fatty acid metabolism, increases calcium absorption, improves bone matrix quality and the stool consistency, and has a positive effect on the development of the intestinal microbiome.

Use of the sleep clinical record in the follow-up of children with obstructive sleep apnea (OSA) after treatment

PURPOSE

The aim of our study was to evaluate the utility of the sleep clinical record (SCR) in the follow-up of children with obstructive sleep apnea (OSA) after treatment.

METHODS

SCR was completed and overnight polysomnography (PSG) was performed in all enrolled children (T0), with SCR considered positive for scores ≥6.5, as previously validated. Patients underwent adenotonsillectomy (T&A), rapid maxillary expansion (RME), and medical therapy according to severity of OSA and clinical features. Six months after completing therapy, the second overnight PSG and SCR (T1) were performed.

RESULTS

For all subjects, both Apnea-Hypopnea Index (AHI) and total SCR score decreased significantly (<0.005) from T0 to T1. For SCR items, clinical examination (item 1) and reported sleep respiratory symptoms (item 2) ameliorated significantly (<0.005). However, hyperactivity or inattention (item 3) decreased significantly (<0.005) after treatment only in T&A group, while no differences in AHI and SCR scores occurred in the medically treated group. At T1, SCR was positive in 95.6 % of children with AHI ≥1, with a concordance of 100 % in the T&A and RME groups, resulting in a positive predictive value of 100 %. A poor concordance (38.3 % in T&A group and 53.4 % in RME group) was found when SCR < 6.5. Children with SCR ≥ 6.5 at T1 showed higher AHI compared to patients with SCR < 6.5 (5.7 ± 5.9 ev/h vs 1.78 ± 1.76 ev/h; p < 0.005).

CONCLUSIONS

SCR emerges as a potentially useful instrument for follow-up of children with OSA after treatment.

Val66Met polymorphism in the BDNF gene in children with bronchial asthma

OBJECTIVES

Bronchial asthma is a chronic respiratory disease characterized by airway inflammation. There is increasing evidence that neurotrophins play an important role in the development and maintenance of neurogenic airway inflammation in chronic allergic diseases.

WORKING HYPOTHESIS

Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family and has several important functions in the airways. There are only a few reports on the association between genetic variations in the BDNF gene and various allergic diseases, and the results are generally conflicting. Therefore, we aimed to study the functional polymorphism Val66Met (also called rs6265 or G196A) in the BDNF gene in a group of asthmatic children and healthy controls.

STUDY DESIGN, PATIENT-SELECTION, AND METHODOLOGY

We studied 248 asthmatic patients (aged 12.28 ± 0.24 years) and 249 healthy children (aged 13.14 ± 0.48 years). Analysis of the Val66Met polymorphism of the BDNF gene was performed by polymerase chain reaction (PCR) and PCR products were digested by PmlI.

RESULTS

The prevalence of the Val66Met polymorphisms (Val/Val, Val/Met, and Met/Met) was 61.7%, 33.5%, and 4.8% in asthmatics, respectively, and 47.0%, 51.8%, and 1.2% in healthy subjects, respectively. We observed a significant association of the Met/Met variant genotype with asthmatics (OR = 4.17, 95% CI = 1.16-14.96, P = 0.018). The Val/Met genotype was protective against bronchial asthma (OR = 0.69, 95% CI = 0.48-0.99, P = 0.045), especially in girls (OR = 0.34, 95% CI = 0.20-0.59, P = 0.001).

CONCLUSION

Specific BDNF gene polymorphism may contribute to bronchial asthma susceptibility. Our study suggested the positive association between selected functional BDNF polymorphism (rs6265) and asthma in children.

The expression profile of acid-sensing ion channel (ASIC) subunits ASIC1a, ASIC1b, ASIC2a, ASIC2b, and ASIC3 in the esophageal vagal afferent nerve subtypes

Acid-sensing ion channels (ASICs) have been implicated in esophageal acid sensing and mechanotransduction. However, insufficient knowledge of ASIC subunit expression profile in esophageal afferent nerves hampers the understanding of their role. This knowledge is essential because ASIC subunits form heteromultimeric channels with distinct functional properties. We hypothesized that the esophageal putative nociceptive C-fiber nerves (transient receptor potential vanilloid 1, TRPV1-positive) express multiple ASIC subunits and that the ASIC expression profile differs between the nodose TRPV1-positive subtype developmentally derived from placodes and the jugular TRPV1-positive subtype derived from neural crest. We performed single cell RT-PCR on the vagal afferent neurons retrogradely labeled from the esophagus. In the guinea pig, nearly all (90%-95%) nodose and jugular esophageal TRPV1-positive neurons expressed ASICs, most often in a combination (65-75%). ASIC1, ASIC2, and ASIC3 were expressed in 65-75%, 55-70%, and 70%, respectively, of both nodose and jugular TRPV1-positive neurons. The ASIC1 splice variants ASIC1a and ASIC1b and the ASIC2 splice variant ASIC2b were similarly expressed in both nodose and jugular TRPV1-positive neurons. However, ASIC2a was found exclusively in the nodose neurons. In contrast to guinea pig, ASIC3 was almost absent from the mouse vagal esophageal TRPV1-positive neurons. However, ASIC3 was similarly expressed in the nonnociceptive TRPV1-negative (tension mechanoreceptors) neurons in both species. We conclude that the majority of esophageal vagal nociceptive neurons express multiple ASIC subunits. The placode-derived nodose neurons selectively express ASIC2a, known to substantially reduce acid sensitivity of ASIC heteromultimers. ASIC3 is expressed in the guinea pig but not in the mouse vagal esophageal TRPV1-positive neurons, indicating species differences in ASIC expression.

Acid infusion into the esophagus increases the number of meal-induced transient lower esophageal sphincter relaxations (TLESRs) in healthy volunteers

BACKGROUND

Transient lower esophageal sphincter relaxation (TLESR) is the major mechanism of gastroesophageal reflux (GER) but the regulation of TLESR by stimuli in the esophagus is incompletely understood. If stimuli in the esophagus can influence TLESR, then such regulation may perpetuate or limit GER. We addressed the hypothesis that acid in the esophagus enhances TLESRs.

METHODS

We evaluated the effect of acid infusion into the distal esophagus on TLESRs evoked by a standard meal in a paired randomized study in healthy subjects. TLESRs were evaluated by using high resolution manometry (HRM).

KEY RESULTS

We found that acid in the esophagus enhanced meal-induced TLESRs. Compared to control infusion the number of TLESRs (median [interquartile range]) was increased during 2 h following the acid infusion (11 [9-14] vs 17 [12.5-20], p < 0.01). The average duration of individual TLESRs was not affected. The time-course analysis revealed that a robust increase in TLESRs occurred already in the first hour when the number of TLESRs nearly doubled (6 [5.5-7.5] vs 11 [7.5-12.5], p < 0.05). In contrast to the enhancement of TLESRs, the number of swallows was not changed.

CONCLUSIONS & INFERENCES

The acid infusion into the esophagus increases the number of meal-induced TLESRs in healthy subjects. Our results provide evidence for the concept that the stimuli in the esophagus can influence TLESRs. The regulation of TLESR by stimuli in the esophagus may contribute to pathogenesis of GER in some patients.

Factors influencing the levels of exhaled carbon monoxide in asthmatic children

OBJECTIVE

Bronchial asthma is characterised by chronic airway inflammation commonly associated with increased oxidative stress. Exhaled carbon monoxide (eCO) levels could act as markers of both oxidative stress and allergic inflammation. We aimed to study eCO levels in asthmatics and detect the possible factors influencing them.

METHODS

We studied 241 asthmatic children and 75 healthy children. The differences in eCO levels among various asthmatic phenotypes and the correlations between eCO and other measured parameters (spirometric indices, Asthma Control Test score, exhaled nitric oxide, total IgE, blood eosinophils and marker of oxidative damage of proteins) were analysed.

RESULTS

Levels of eCO widely differed according to the selected characteristics of asthma. Asthmatics showed higher eCO concentrations than controls (1.44 ± 0.12 ppm vs. 0.91 ± 0.11 ppm, p < 0.001). Acute exacerbation of asthma was accompanied by a significant increase in eCO compared to the clinically controlled stage (2.17 ± 0.36 ppm vs. 1.33 ± 0.13 ppm, p < 0.001). Atopic, non-atopic asthma and asthma associated with allergic rhinitis (AR) showed elevated levels of eCO. The levels of eCO negatively correlated with the marker of protein oxidation in asthmatics, especially in atopic form and during acute exacerbation.

CONCLUSIONS

In a population of asthmatic children, eCO levels could be considered as a marker of both allergic inflammation and oxidative stress in the airways. Concomitant AR and asthma control were the most important factors affecting the levels of eCO in asthmatic children. However, our results do not support the use of routine eCO in the clinical practice.

β-Glucans in the treatment and prevention of allergic diseases

β-glucans are a group of biologically active polysaccharides of natural origin with a proven pleiotropic immunomodulation effect. Their efficacy has been confirmed in the therapeutic treatment and prevention of various infectious diseases, secondary immune defects and also of oncologic disorders. Allergic diseases are one of the most frequent diseases and their prevalence continues to increase. They develop as a consequence of dysregulation of the immune system, especially when there is failure in the equilibrium of the response of TH1/TH2 lymphocytes towards TH2. New therapeutic approaches in the treatment of immunopathological conditions (e.g. allergic or oncologic) are directed to restoring the equilibrium among different T lymphocyte subpopulations. Based on in vitro experiments, and also on animal and human clinical studies, there is much evidence for the importance of β-glucans in the treatment and also prevention of allergic diseases; this opens new perspectives on the use of this widespread and popular group of natural substances.

Pulmonary manifestations of primary immunodeficiency disorders in children

Primary immunodeficiencies (PIDs) are inherited disorders in which one or several components of immune system are decreased, missing, or of non-appropriate function. These diseases affect the development, function, or morphology of the immune system. The group of PID comprises more than 200 different disorders and syndromes and the number of newly recognized and revealed deficiencies is still increasing. Their clinical presentation and complications depend on the type of defects and there is a great variability in the relationship between genotypes and phenotypes. A variation of clinical presentation across various age categories is also presented and children could widely differ from adult patients with PID. Respiratory symptoms and complications present a significant cause of morbidity and also mortality among patients suffering from different forms of PIDs and they are observed both in children and adults. They can affect primarily either upper airways (e.g., sinusitis and otitis media) or lower respiratory tract [e.g., pneumonia, bronchitis, bronchiectasis, and interstitial lung diseases (ILDs)]. The complications from lower respiratory tract are usually considered to be more important and also more specific for PIDs and they determinate patients' prognosis. The spectrum of the causal pathogens usually demonstrates typical pattern characteristic for each PID category. The respiratory signs of PIDs can be divided into infectious (upper and lower respiratory tract infections and complications) and non-infectious (ILDs, bronchial abnormalities - especially bronchiectasis, malignancies, and benign lymphoproliferation). Early diagnosis and appropriate therapy can prevent or at least slow down the development and course of respiratory complications of PIDs.

Wiskott-Aldrich syndrome caused by a new mutation associated with multifocal dermal juvenile xanthogranulomas

Wiskott-Aldrich syndrome is a rare X-linked primary immunodeficiency clinically characterized by the triad of microthrombocytopenia, immunodeficiency, and eczema. Juvenile xanthogranuloma is a well-recognized benign disorder of infancy and early childhood from the group of non-Langerhans cell histiocytoses, with a good prognosis and spontaneous involution. We report a boy with Wiskott-Aldrich syndrome caused by a new, not previously described mutation associated with multifocal juvenile xanthogranuloma.

Frequency of polymorphism -262 c/t in catalase gene and oxidative damage in Slovak children with bronchial asthma

INTRODUCTION

Bronchial asthma is a complex disease in which genetic factors, environmental factors and oxidative damage are responsible for the initiation and modulation of disease progression. If antioxidant mechanisms fail, reactive oxygen species damage the biomolecules followed by progression of the disease. Catalase is one of the most important endogenous enzymatic antioxidants. In the present study, we examined the hypothesis that increased oxidative damage and polymorphism in the CAT gene (-262 promoter region, C/T) are associated with childhood bronchial asthma.

PATIENTS AND METHODS

Genotyping of the polymorphisms in the CAT gene in healthy (249) and asthmatic children (248) was performed using polymerase chain reaction-restriction fragment length polymorphism. Markers of oxidative damage: content of sulfhydryl groups and thiobarbituric acid-reactive substances were determined by spectrophotometry in children.

RESULTS

The TT genotype of catalase was more frequent among the asthmatic patients (22.6%) than in healthy children (4.8%) (odds ratio=5.63; 95% confidence interval=2.93-10.81, P<.001). The amount of sulfhydryl groups decreased significantly and conversely, the content of thiobarbituric acid-reactive substances increased significantly in bronchial asthma and in catalase TT genotype compared to other catalase genotypes of this gene.

CONCLUSIONS

These results suggest that catalase polymorphism might participate in development of bronchial asthma and in enhanced oxidative damage in asthmatic children. Genetic variation of enzymatic antioxidants may modulate disease risk.