A nephrogenic mechanism underlies dexmedetomidine-induced polyuria. A case report

Dexmedetomidine's α-adrenoreceptor agonism has been gaining popularity in the anesthetic room as a sedative-hypnotic and analgesic agent, and with extensive perioperative use rising concern about side effects is necessary. Bradycardia and hypotension are common adverse effects, but there are also several reports of excessive urine output, possibly due to vasopressin secretion and permeability of collecting ducts. Polyuria usually resolves with discontinuation of the drug, and significant morbidity has not been reported. Early identification, removal of the agent, and treatment are imperative to minimize complications - mainly natremia and neurological symptoms. This case report describes a dexmedetomidine-related polyuric syndrome during opioid-free general anesthesia for major head and neck surgery. A nephrogenic mechanism for the clinical effect is proposed and reinforced by analytical data obtained. An intra-operative polyuria approach is also delineated.

Erector spinae plane block for surgery of esophageal atresia in a preterm neonate

Pain management during and after thoracotomy is challenging in premature neonates. Ultrasound-guided fascial plane block techniques, such as the erector spinae plane block are a relatively new regional anesthesia technique and have emerged as an alternative to thoracic epidural due to its clinical effectiveness, ease of administration and theoretically being safer to perform. The relative ease of identifying anatomical landmarks compared to the paravertebral block, as well as its safety profile compared to an epidural, may have contributed to the erector spinae plane Bs growing popularity. Currently, however, the published evidence for the efficacy of regional anesthesia techniques in low birth weight newborns undergoing this surgery is limited to few isolated case reports. Herein we describe the use of unilateral erector spinae plane block as part of anesthesia and postoperative analgesia management of surgical correction of esophageal atresia in a preterm neonate.

Allergies and COVID-19 vaccines: An ENDA/EAACI Position paper

BACKGROUND

Anaphylaxis, which is rare, has been reported after COVID-19 vaccination, but its management is not standardized.

METHOD

Members of the European Network for Drug Allergy and the European Academy of Allergy and Clinical Immunology interested in drug allergy participated in an online questionnaire on pre-vaccination screening and management of allergic reactions to COVID-19 vaccines, and literature was analysed.

RESULTS

No death due to anaphylaxis to COVID-19 vaccines has been confirmed in scientific literature. Potential allergens, polyethylene glycol (PEG), polysorbate and tromethamine are excipients. The authors propose allergy evaluation of persons with the following histories: 1-anaphylaxis to injectable drug or vaccine containing PEG or derivatives; 2-anaphylaxis to oral/topical PEG containing products; 3-recurrent anaphylaxis of unknown cause; 4-suspected or confirmed allergy to any mRNA vaccine; and 5-confirmed allergy to PEG or derivatives. We recommend a prick-to-prick skin test with the left-over solution in the suspected vaccine vial to avoid waste. Prick test panel should include PEG 4000 or 3500, PEG 2000 and polysorbate 80. The value of in vitro test is arguable.

CONCLUSIONS

These recommendations will lead to a better knowledge of the management and mechanisms involved in anaphylaxis to COVID-19 vaccines and enable more people with history of allergy to be vaccinated.

Cauda equina syndrome following combined spinal-epidural anesthesia with levobupivacaine for cesarean section

Cauda equina syndrome (CES) is a rare but possible complication of neuroaxial anesthesia. Damage to the nerve roots may occur due to compression, inflammation, stretching, direct trauma, spinal ischemia or neurotoxicity, usually with lidocaine or bupivacaine. We describe a case of a 33-year-old patient that underwent an uneventful cesarean section with a combined spinal-epidural technique anesthesia, with levobupivacaine. 48 h after the procedure, she presented diminished muscular strength and abolished osteotendinous reflexes in the left lower limb, limited flexion of the right hallux, urinary retention and saddle anesthesia. Imaging exams excluded hematoma, thickening or compression of the cauda equina nerve roots. CES was suspected and treatment was initiated. 9-month follow up revealed diminished osteotendinous reflexes on the left lower limb and perianal hypoesthesia. Despite being unusual, neurological complications require prompt recognition and management to avoid permanent damage.

Chronic urticaria in the real-life clinical practice setting in the UK: results from the noninterventional multicentre AWARE study

BACKGROUND

Chronic urticaria (CU) is a skin condition characterized by repeated occurrence of itchy weals and/or angio-oedema for > 6 weeks.

AIM

To provide data demonstrating the real-life burden of CU in the UK.

METHODS

This UK subset of the worldwide, prospective, noninterventional AWARE study included patients aged 18-75 years diagnosed with H1-antihistamine (H1-AH)-refractory chronic spontaneous urticaria (CSU) for > 2 months. Baseline characteristics, disease activity, treatments, comorbidities and healthcare resource use were documented. Quality of life (QoL), work productivity and activity impairment were assessed.

RESULTS

Baseline analysis included 252 UK patients. Mean age and body mass index were 45.0 years and 29.0 kg/m² , respectively. Most patients were female (77.8%) and had moderate/severe disease activity (mean Urticaria Activity Score over 7 days was 18.4) and a 'spontaneous' component to their CU (73.4% CSU; 24.6% CSU and chronic inducible urticaria). Common comorbidities included depression/anxiety (24.6%), asthma (23.8%) and allergic rhinitis (12.7%). A previous treatment was recorded for 57.9% of patients. Mean Dermatology Life Quality Index score was 9.5, and patients reported impairments in work productivity and activity. Healthcare resource use was high. Severity of CSU was associated with female sex, obesity, anxiety and diagnosis. Only 28.5% of patients completed all nine study visits, limiting analysis of long-term treatment patterns and disease impact.

CONCLUSIONS

Adult H1-AH-refractory patients with CU in the UK reported high rates of healthcare resource use and impairment in QoL, work productivity and activity at baseline. The differing structures of UK healthcare may explain the high study discontinuation rates versus other countries.

Subcutaneous emphysema as a complication of the use of a laryngeal mask in a child

The use of supraglottic airway devices has been increasing in popularity, mostly due to their high success rate and low complications. However, there is very little information available about the potential and group specific concerns regarding their use in children. We present the first description of a child that developed subcutaneous emphysema after the use of a laryngeal mask. We believe that more awareness to the risk of perioperative adverse events with laryngeal mask insertion in the paediatric population is needed.

In vitro T-cell profile induced by BCG Moreau in healthy Brazilian volunteers

Tuberculosis (TB) remains the world's leading cause of morbidity and mortality. Although Mycobacterium bovis bacillus Calmette-Guérin (BCG) is the only vaccine currently in use, its efficacy is highly variable. It has been suggested that early antigenic presentation is a pivotal event leading to a better immune response in TB vaccine models. To investigate this further, we compared in vitro cell-mediated immune responses in the context of early sensitization with TB (i.e. healthy adults vaccinated with BCG when they were young, HD; n = 25) to those in its absence (i.e., newborns with naïve immunity to TB, UV; n = 10) by challenging mononuclear cells with BCG Moreau. After 48 hours, CD4+ and CD8+ T cells were harvested from both groups and stained for PD-1/CD25/ FOXP3. In addition, supernatants were assayed for a broad range of cytokines using an array system. The HD group showed robust reactivity to Protein Purified Derivative and BCG while the naïve, UV group did not. Similarly, in terms of PD-1 expression and Treg cells (CD4+/CD25high(+)/FOXP3+), only the HD group showed higher levels in CD4 lymphocytes. Otherwise, only the UV group showed expression of CD25dim+ as an activation marker dependent on BCG infection. In terms of cytokines, the HD group showed higher levels of Th1 (IL-2/TNF-α/IFN-γ) and regulatory (IL-10) profiles, with monocytes, but not Tr1 cells, acting as the main source of IL-10. Taken together, our results highlight critical roles of early sensitization with TB in mounting cell-mediated immune responses.

Predicting phenotypes of asthma and eczema with machine learning

Background

There is increasing recognition that asthma and eczema are heterogeneous diseases. We investigated the predictive ability of a spectrum of machine learning methods to disambiguate clinical sub-groups of asthma, wheeze and eczema, using a large heterogeneous set of attributes in an unselected population. The aim was to identify to what extent such heterogeneous information can be combined to reveal specific clinical manifestations.

Methods

The study population comprised a cross-sectional sample of adults, and included representatives of the general population enriched by subjects with asthma. Linear and non-linear machine learning methods, from logistic regression to random forests, were fit on a large attribute set including demographic, clinical and laboratory features, genetic profiles and environmental exposures. Outcome of interest were asthma, wheeze and eczema encoded by different operational definitions. Model validation was performed via bootstrapping.

Results

The study population included 554 adults, 42% male, 38% previous or current smokers. Proportion of asthma, wheeze, and eczema diagnoses was 16.7%, 12.3%, and 21.7%, respectively. Models were fit on 223 non-genetic variables plus 215 single nucleotide polymorphisms. In general, non-linear models achieved higher sensitivity and specificity than other methods, especially for asthma and wheeze, less for eczema, with areas under receiver operating characteristic curve of 84%, 76% and 64%, respectively. Our findings confirm that allergen sensitisation and lung function characterise asthma better in combination than separately. The predictive ability of genetic markers alone is limited. For eczema, new predictors such as bio-impedance were discovered.

Conclusions

More usefully-complex modelling is the key to a better understanding of disease mechanisms and personalised healthcare: further advances are likely with the incorporation of more factors/attributes and longitudinal measures.

17q12-21 and asthma: interactions with early-life environmental exposures

BACKGROUND

17q12-21 polymorphisms are associated with asthma presence and severity across different populations.

OBJECTIVE

To extensively investigate the genes in this region among Croatian schoolchildren in a case-control study, taking account of early-life environmental exposures.

METHODS

We included 423 children with asthma and 414 controls aged 5 to 18 years. Fifty-one haplotype tagging single-nucleotide polymorphisms (SNPs) were genotyped (GSDMA, GSDMB, ORMDL3, IKZF3, ZPBP2, and TOP2). Data on exposure to smoking and furry pet ownership were collected using a validated questionnaire. Information on severe asthma exacerbations with hospital admission were retrieved from hospital notes. All patients underwent spirometry.

RESULTS

We found 2 SNPs (1 novel rs9635726 in IKZF3) to be associated with asthma. Among children with asthma, 4 SNPs (in ZPBP2, GSDMB, and GSDMA) were associated with hospital admissions and 8 SNPs with lung function. One SNP (rs9635726) remained significantly associated with a predicted forced expiratory volume in 1 second after false discovery rate correction. Nine markers across 5 genes showed interaction with early-life environmental tobacco smoke (ETS) exposure in relation to asthma and 2 with furry pet ownership. Among children with asthma, we observed significant interactions between early-life ETS exposure and 3 SNPs for lung function and among early-life ETS exposure, 3 SNPs (in ORMDL3 and GSDMA), and hospital admission with asthma exacerbation. Three SNPs (in ORMDL3) interacted with current furry pet ownership in relation to hospital admissions for asthma exacerbation.

CONCLUSION

Our results indicate that several genes in the 17q12-21 region may be associated with asthma. This study confirms that environmental exposures may need to be included into the genetic association studies.

Asthma severity, polymorphisms in 20p13 and their interaction with tobacco smoke exposure

BACKGROUND

We investigated the association between genetic variation in chromosomal region 20p13-p12 (ADAM33 and flanking genes ATRN, GFRA4, SIGLEC1 and HSPA12B) and asthma. Amongst asthmatics, we then investigated the association between genetic variants and asthma severity. We evaluated the effect of environmental tobacco smoke (ETS) exposure in the context of genetic variants.

METHODS

In a case-control study, we recruited 423 asthmatic children and 414 non-asthmatic controls (age 5-18 yr). Amongst asthmatics, we measured lung function and extracted data on hospitalisation for asthma exacerbation from medical records. Early-life ETS exposure was assessed by questionnaire. We included 85 single-nucleotide polymorphisms (SNPs) in the analysis.

RESULTS

Seventeen SNPs were significantly associated with asthma; one (rs41534847 in ADAM33) remained significant after correction for multiple testing. Thirty-six SNPs were significantly associated with lung function, of which 15 (six ARTN, three ADAM33, five SIGLEC1 and one HSPA12B) remained significant after correction. We observed a significant interaction between 23 SNPs and early-life ETS exposure in relation to lung function measures. For example, for rs512625 in ADAM33, there was significant interaction with ETS exposure in relation to hospitalisations (p(int)  = 0.02) and lung function (p(int)  = 0.03); G-allele homozygotes had a 9.15-fold [95% CI 2.28-36.89] higher risk of being hospitalized and had significantly poorer lung function if exposed to ETS, with no effect of ETS exposure amongst A-allele carriers.

CONCLUSION

We demonstrated several novel significant interactions between polymorphisms in 20p13-p12 and early-life ETS exposure with asthma presence and, amongst asthmatics, a significant association with the severity of their disease.

Gene-environment interactions in the development of asthma and atopy

Asthma is a complex multifactorial disorder involving a variety of different mechanisms. Little has changed in asthma treatment over the past five decades. There is evidence for a strong genetic component of asthma, but genetic studies have produced heterogeneous results with little replication, with most of the heritability remaining unexplained. The rapid increase in asthma prevalence over a short time period suggests that environmental exposures play an important role, but there is a considerable heterogeneity in the results describing the effect of different environmental exposures. There are many reasons for the lack of replication in genetic association studies and those of environmental exposures. These include the failure to consider that asthma may arise as a consequence of environmental factors, modulating the risk in genetically susceptible individuals via gene-environment interactions. In addition, many studies rely on oversimplified phenotypes often derived through aggregation of several heterogeneous conditions (e.g., 'physician-diagnosed asthma').

Genetic variation in vascular endothelial growth factor-a and lung function

RATIONALE

Given the role of vascular endothelial growth factor (VEGF) in lung development, we hypothesized that polymorphisms in VEGF-A may be associated with lung function.

OBJECTIVES

The current study was designed to assess the role of genetic variants in VEGF-A as determinants of airway function from infancy through early adulthood.

METHODS

Association between five single-nucleotide polymorphisms (SNPs) in VEGF-A and lung function were assessed longitudinally in two unselected birth cohorts and cross-sectionally among infants. Replication with two SNPs was conducted in adults and children with asthma. We investigated the functionality of the SNP most consistently associated with lung function (rs3025028) using Western blotting to measure the ratio of plasma VEGF-A(165b)/panVEGF-A(165) among homozygotes.

MEASUREMENTS AND MAIN RESULTS

In two populations in infancy, C-allele homozygotes of rs3025028 had significantly higher VmaxFRC, forced expiratory flow(50), and forced expiratory flow(25-75) compared with other genotype groups. Among preschool children (age 3 yr), C allele of rs3025028 was associated with significantly higher specific airway conductance, with similar findings observed for lung function in school-age children. For FEV(1)/FVC ratio similar findings were observed among adolescents and young adults (birth cohort), and then replicated in adults and schoolchildren with asthma (cross-sectional studies). For rs3025038, plasma VEGF-A(165b)/panVEGF-A(165) was significantly higher among CC versus GG homozygotes (P ≤ 0.02) at birth, in school-age children, and in adults.

CONCLUSIONS

We report significant associations between VEGF-A SNP rs3025028 and parameters of airway function measured throughout childhood, with the effect persisting into adulthood. We propose that the mechanism may be mediated through the ratios of active and inhibitory isoforms of VEGF-A(165), which may be determined by alternative splicing.

Quantification of atopy, lung function and airway hypersensitivity in adults

BACKGROUND

Studies in children have shown that concentration of specific serum IgE (sIgE) and size of skin tests to inhalant allergens better predict wheezing and reduced lung function than the information on presence or absence of atopy. However, very few studies in adults have investigated the relationship of quantitative atopy with lung function and airway hyperresponsiveness (AHR).

OBJECTIVE

To determine the association between lung function and AHR and quantitative atopy in a large sample of adults from the UK.

METHODS

FEV1 and FVC (% predicted) were measured using spirometry and airway responsiveness by methacholine challenge (5-breath dosimeter protocol) in 983 subjects (random sample of 800 parents of children enrolled in a population-based birth cohort enriched with 183 patients with physician-diagnosed asthma). Atopic status was assessed by skin prick tests (SPT) and measurement of sIgE (common inhalant allergens). We also measured indoor allergen exposure in subjects' homes.

RESULTS

Spirometry was completed by 792 subjects and 626 underwent methacholine challenge, with 100 (16.0%) having AHR (dose-response slope>25). Using sIgE as a continuous variable in a multiple linear regression analysis, we found that increasing levels of sIgE to mite, cat and dog were significantly associated with lower FEV1 (mite p = 0.001, cat p = 0.0001, dog p = 2.95 × 10-8). Similar findings were observed when using the size of wheal on skin testing as a continuous variable, with significantly poorer lung function with increasing skin test size (mite p = 8.23 × 10-8, cat p = 3.93 × 10-10, dog p = 3.03 × 10-15, grass p = 2.95 × 10-9). The association between quantitative atopy with lung function and AHR remained unchanged when we repeated the analyses amongst subjects defined as sensitised using standard definitions (sIgE>0.35 kUa/l, SPT-3 mm>negative control).

CONCLUSIONS

In the studied population, lung function decreased and AHR increased with increasing sIgE levels or SPT wheal diameter to inhalant allergens, suggesting that atopy may not be a dichotomous outcome influencing lung function and AHR.

Quantification of atopy and the probability of rhinitis in preschool children: a population-based birth cohort study

BACKGROUND

Atopy quantification using IgE levels/skin test diameter (SPT-MWD) may better predict the expression of rhinitis than using atopy as a dichotomous variable.

OBJECTIVE

To investigate the association between the presence, temporal pattern and severity of rhinitis in preschool children and specific IgE levels/SPT-MWDs.

METHODS

Children were followed prospectively to age 5 years in a whole-population birth cohort study. We administered questionnaires (n = 815), skin prick tested children (n = 717) and measured specific serum IgE (n = 478) to inhalant and food allergens. Main outcomes were current rhinitis (CR) and current rhinoconjunctivitis (CRC).

RESULTS

The prevalence of CR and CRC was 26.1% and 12.1%, respectively. The risk of CR and CRC increased significantly with increasing IgE to grass, mite and cat; CRC was also associated with increasing IgE to dog and peanut. Similarly, increasing SPT-MWDs to inhalant allergens were significantly associated with CR and CRC. This association was also shown for grass within the group of atopic children. Perennial and seasonal rhinitis were associated with increasing IgE/SPT-MWD to mite and grass, respectively. Moderate/severe rhinitis was associated with increasing IgE/SPT-MWD to grass. In a multivariate analysis, increasing levels of IgE/SPT-MWD to grass were the strongest independent predictors of both CR (for IgE: OR 1.42, 95% CI 1.23-1.64, P < 0.001) and CRC (for IgE: 1.51, 1.30-1.76, P < 0.001).

CONCLUSION

The probability of CR/CRC increases with increasing specific IgE levels or SPT-MWD. With respect to allergic rhinitis, the absolute levels of specific IgE antibody or the size of SPT wheal offer more information than just the presence/absence of sensitization.

Rhinoconjunctivitis in 5-year-old children: a population-based birth cohort study

BACKGROUND

There is a paucity of data on the prevalence, risk factors and natural history of rhinitis in early childhood.

OBJECTIVE

Within the context of a whole-population birth cohort we investigated the prevalence of and risk factors for current rhinoconjunctivitis (CRC) at age 5 years.

METHODS

Children were followed prospectively to age 5 years [questionnaires (n = 815), skin testing (n = 717), specific immunoglobulin E (n = 478), lung function (n = 711), dry air challenge (n = 556)]. Endotoxin and allergen exposures were measured in dust samples.

RESULTS

The prevalence of rhinitis ever, current rhinitis and rhinoconjunctivitis was 28.2%, 26.1%, and 12.1%, respectively. Asthma, wheeze and eczema coexisted with CRC (P < or = 0.01). In a multivariate model, maternal asthma (OR 2.38, 95% CI: 1.30-4.38, P = 0.005), paternal hay fever (1.96, 1.11-3.46, P = 0.02) and sensitization to grass (3.46, 1.86-6.42, P < 0.001) and cat (2.42, 1.14-5.18, P = 0.02) remained significant and independent associates of CRC. Whilst almost half of children with CRC were nonatopic, there was little difference in risk factors between atopic and nonatopic CRC. Amongst children with current wheeze, the presence of concurrent CRC had no effect on either severity or frequency of wheezy episodes. There was no difference in specific airway resistance, forced expiratory volume in 1 second (FEV(1)) or airway reactivity between children with and without CRC after adjustment for the presence of wheeze.

CONCLUSION

Family history of allergic disease and sensitization to inhalant allergens are risk factors for rhinoconjunctivitis in preschool children. In this age group, there is no association between the presence of rhinoconjunctivitis and severity of wheeze, increased airway reactivity and reduced lung function.

Allergen avoidance in the secondary and tertiary prevention of allergic diseases: does it work?

Although allergen avoidance is widely recommended as part of a secondary and tertiary prevention strategy for allergic diseases, a clear-cut demonstration of its effectiveness is still lacking. Ongoing observational secondary prevention cohorts show that sensitisation to mite can be prevented in the short term by allergen avoidance measures, but further follow-up of these children is needed to show if this effect can be sustained, as well as to ascertain its impact on allergic disease. More well-designed trials are still required before we can give any conclusive advice to our patients. Considering the management of allergy, current evidence suggests that interventions in children (either single or multifaceted) may be associated with some beneficial effect on asthma control, but no conclusive evidence exists regarding rhinitis or eczema. Conversely, there is little evidence to support the recommendation of allergen avoidance methods in adults with asthma and rhinitis. There is a need for an adequately designed trial assessing the effects of a multifaceted intervention in this age group.

Barnacle allergy: allergen characterization and cross-reactivity with mites

BACKGROUND

Barnacles are a type of seafood with worldwide distribution and abundant along the shores of temperate seas. They are particularly appreciated and regularly consumed in Portugal as well as in Spain, France and South America, but barnacle allergy is a rare condition of which there is only one reference in the indexed literature. The molecular allergens and possible cross-reactivity phenomena implicated (namely with mites) have not been established.

OBJECTIVE

To demonstrate the IgE-mediated allergy to barnacle and to identify the proteins implicated as well as possible cross-reactivity phenomena with mites.

METHODS

We report the clinical and laboratory data of five patients with documented IgE-mediated allergy to barnacle. The diagnosis was based on a suggestive clinical history combined with positive skin prick tests (SPT) to barnacle--prick to prick method. Two barnacle extracts were prepared (raw and cooked barnacle) and sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE) and IgE-immunoblotting were performed. An immunoblotting inhibition assay with Dermatophagoides pteronyssinus was also done in order to evaluate cross-reactivity.

RESULTS

All patients had mite-related asthma and the allergic rhinoconjunctivitis; they all experienced mucocutaneous symptoms. All of them had positive SPT to barnacle, and the immunoblotting showed several allergenic fractions with a wide molecular weight range (19 - 94 kDa). The D. pteronyssinus extract inhibited several IgE-binding protein fractions in the barnacle extract.

CONCLUSIONS

We describe five patients with IgE-mediated barnacle allergy. We also describe a group of IgE-binding+proteins between 30 and 75 kDa as the allergenic fractions of this type of Crustacea. Cross-reactivity with D. pteronyssinus was demonstrated in two cases.

Cold urticaria and infectious mononucleosis in children

Physical urticaria includes a heterogeneous group of disorders characterized by the development of urticarial lesions and/or angioedema after exposure to certain physical stimuli. The authors present the case of a child with severe acquired cold urticaria secondary to infectious mononucleosis. Avoidance of exposure to cold was recommended; prophylactic treatment with ketotifen and cetirizine was begun and a self-administered epinephrine kit was prescribed. The results of ice cube test and symptoms significantly improved. Physical urticaria, which involves complex pathogenesis, clinical course and therapy, may be potentially life threatening. Evaluation and diagnosis are especially important in children. To our knowledge this is the first description of persistent severe cold-induced urticaria associated with infectious mononucleosis in a child.