Author Correction: A human immune dysregulation syndrome characterized by severe hyperinflammation with a homozygous nonsense Roquin-1 mutation.

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A human immune dysregulation syndrome characterized by severe hyperinflammation with a homozygous nonsense Roquin-1 mutation.

Hyperinflammatory syndromes are life-threatening disorders caused by overzealous immune cell activation and cytokine release, often resulting from defects in negative feedback mechanisms. In the quintessential hyperinflammatory syndrome familial hemophagocytic lymphohistiocytosis (HLH), inborn errors of cytotoxicity result in effector cell accumulation, immune dysregulation and, if untreated, tissue damage and death. Here, we describe a human case with a homozygous nonsense R688* RC3H1 mutation suffering from hyperinflammation, presenting as relapsing HLH. RC3H1 encodes Roquin-1, a posttranscriptional repressor of immune-regulatory proteins such as ICOS, OX40 and TNF. Comparing the R688* variant with the murine M199R variant reveals a phenotypic resemblance, both in immune cell activation, hypercytokinemia and disease development. Mechanistically, R688* Roquin-1 fails to localize to P-bodies and interact with the CCR4-NOT deadenylation complex, impeding mRNA decay and dysregulating cytokine production. The results from this unique case suggest that impaired Roquin-1 function provokes hyperinflammation by a failure to quench immune activation.

Hepatitis B virus vaccination and revaccination response in children diagnosed with coeliac disease : a multicentre prospective study.

AIM: This study evaluates hepatitis B virus (HBV) vaccination response in children with celiac disease (CD). Response in initial non-responders after a single booster vaccination as well as factors influencing HBV vaccination response were evaluated. METHODOLOGY: Anti-hepatitis B surface antibodies (a-HBsAB) were checked in all children with CD and a documented complete HBV vaccination. An a-HBsAB <10 U/L was considered as non-response. A single intramuscular HBV-vaccine booster was advised to all non-responders. Response was checked at the next appointment. RESULTS: 133 children with CD were included, median age of 7.3 years (range 1.7-17.3) and 46 (35%) were male. The age at CD diagnosis was 6.0 years (range 1.1-15.7). HBV non-response was documented in 55% (n=73/133). No other factors were influencing the response. A booster was documented in 34/73 (47 %) initial non-responders (3 refused (4%), 36 (49%) had no follow up). Response after booster vaccination resulted in immunity in 22/34 (65%) and persisting non-response in 12/34 (35%). A single booster is able to reduce non-response from 55% (73/133) to 23% (22/94). CONCLUSION: A significantly lower immune response following HBV vaccination in children with CD was confirmed. A single intramuscular booster vaccination is able to induce a serologic response in two thirds of the initial non-responders. Control of HBV vaccination response has to become part of the follow-up in CD patients.

Emergence of livestock-associated MRSA isolated from cystic fibrosis patients: Result of a Belgian national survey.

BACKGROUND: This study aims to determine the prevalence and characteristics of Staphylococcus aureus in Belgian cystic fibrosis (CF) patients. METHODS: Non-duplicate respiratory samples from 510 CF-patients (2012-2013) were examined. One isolate per patient was analysed unless different phenotypes were recovered. Isolates were investigated for mecA/mecC, toxins presence, spa-typing, MLST and SCCmec-typing. Potential livestock-associated (LA) isolates were examined for their immune-evasion-cluster (IEC) genes. RESULTS: S. aureus (n = 380), including 41 small-colony variants (SCVs), were isolated from 66.7% patients. The prevalence of methicillin-resistant S. aureus (MRSA) colonization was 4.9%. Two MRSA isolates carried toxic shock syndrome toxin 1 (TSST-1). Most MRSA (65%) belonged to two nosocomial epidemic clones (CC5, CC8) widespread in Belgium. Methicillin susceptible S. aureus (MSSA) showed great genetic diversity. Five of 33 isolates belonging to potential LA-lineages were IEC negative, including three methicillin-resistant isolates, suggesting an animal origin. CONCLUSIONS: The MRSA-prevalence in Belgian CF-patients remained constant (2001-2013), but SCV-prevalence increased. Most MRSA belonged to health-care-associated clones. Three patients carrying LA-MRSA were found, requiring further investigation to determine the risk factors for LA-MRSA acquisition.

Pulmonary interstitial glycogenosis - A systematic analysis of new cases.

BACKGROUND: Pulmonary interstitial glycogenosis (PIG) is a rare paediatric interstitial lung disease of unknown cause. The diagnosis can only be made by lung biopsy. Less than 100 cases have been reported. Clinical features, treatment and outcomes have rarely been assessed systematically in decent cohorts of patients. METHODS: In this retrospective multicentre study, the clinical presentation, radiologic findings, pattern of lung biopsy, extrapulmonary comorbidities, treatment and outcome of eleven children with PIG were collected systematically. RESULTS: 10/11 children presented with respiratory distress immediatly after birth and 8/11 needed invasive ventilation. In 8/11 children extrapulmonary comorbidities were present, congenital heart defects being the most common. 7/11 children received systemic glucocorticoids and of these four showed a clear favorable response. During a median follow-up of 3.0 years (range 0.42-12.0) one child died, while 10 patients improved. Chest CT-scans showed ground-glass opacities (7/10), consolidations (6/10), linear opacities (5/10) and mosaic attenuation (4/10) without uniform pattern. Besides interstitial thickening related to undifferentiated glycogen positive mesenchymal cells all tissue samples showed growth abnormalities with reduced alveolarization. CONCLUSIONS: PIG is associated with alveolar growth abnormalities and has to be considered in all newborns with unexplained respiratory distress. Apparent treatment benefit of glucocorticosteroids needs to be evaluated systematically.

Achromobacter xylosoxidans induced bronchiolitis obliterans in cystic fibrosis.

We report a 12-year-old boy with progressive bronchiolitis obliterans caused by Achromobacter xylosoxidans (Ax) colonization after liver transplantation, resulting in a steep decline in lung function.

Genetic variations in toll-like receptor pathway and lung function decline in Cystic fibrosis patients.

The toll-like receptor (TLR) family maintains pulmonary homeostasis by pathogen recognition, clearance and regulation of inflammation. Genes affecting inflammation response play a key role in modifying Cystic fibrosis (CF) lung disease severity. We assessed the impact of single nucleotide polymorphisms (SNPs) of TLR genes (TLR1 to TLR10, CD14, lipopolyssacharide-binding protein (LBP)) on lung function in CF patients. Each SNP was tested for time-dependent effect on FEV1, using six genetic models. In addition, we investigated associations between SNP genotypes and extreme subject specific slopes of FEV1 decline. Variant alleles of polymorphisms of TLR2 rs1898830, rs5743708, and rs3804100 demonstrated a consistent association with lung disease severity (p = 0.008, p = 0.006 and p = 0.029 respectively). Patients homozygous for variant C allele of TLR5 polymorphism rs5744174 are more frequently associated with extreme fast FEV1 decline (OR: 20 (95% Confidence Interval:1.85-216.18)). Patients homozygous AA for TLR1 polymorphism rs5743551 are more frequently associated with faster decline of FEV1 compared to heterozygous genotype (OR:7.33 (95% CI:1.63-33.11). Our findings indicate that variations in TLR1, TLR2 and TLR5 genes may influence CF lung function decline. Further functional analysis is required to provide new insights into the pathogenesis of TLRs in CF lung disease severity.

Polymorphisms in the lectin pathway genes as a possible cause of early chronic Pseudomonas aeruginosa colonization in cystic fibrosis patients.

Genes of innate immunity may be involved in early onset of chronic Pa (Pseudomonas aeruginosa) colonization (cPaC) in cystic fibrosis (CF) patients. We studied 19 single nucleotide polymorphisms (SNPs) in 5 genes coding for proteins of the lectin complement pathway: MBL2 (Mannose binding lectin 2), MASP 1, 2, 3 (MBL-associated serine Protease) and FCN 1, 2 (Ficolin) gene in 96 CF patients. Association survival analysis using different genetic models was performed looking for an association between SNPs and age at onset of cPaC. CF patients who are MBL deficient are earlier chronic Pa colonized compared to MBL sufficient patients. Also patients with MBL2 genotype YO/YO, YO/XA, XA/XA, YA/YO and YA/XA are earlier chronic Pa colonized. CF patients heterozygous or homozygous for mutant alleles of two linked SNPs in the FCN1 gene (rs2989727 and rs1071583) are earlier colonized with Pa. Similarly, earlier onset of Pa colonization is seen in CF patients heterozygous for linked SNPs of FCN2 gene (rs7865453 and rs7851696) and MASP3 gene (rs7851696). Variants in MBL2, FCN1, FCN2 and MASP3 genes are significantly associated with earlier onset of chronic P. aeruginosa colonization.

Malacia, inflammation and bronchoalveolar lavage culture in children with persistent respiratory symptoms.

In children with persistent respiratory symptoms despite regular anti-asthma inhalation treatment, diagnostic investigations to exclude underlying disease are warranted. 124 children were prospectively enrolled, and 24-h oesophageal pH measurement and fibreoptic bronchoscopy with bronchoalveolar lavage (BAL) were performed. BAL fluid (BALF) was processed for neutrophil counting and bacterial culture. Inflammation of the respiratory mucosa was assessed. A structural abnormality of the central airways was found in 47% of subjects (40% females). In 19% of subjects, neither anatomical anomalies nor inflamed respiratory mucosa were observed, whereas in 64%, definite macroscopic mucosal inflammation was observed. Inflammation of the respiratory mucosa was associated with a significantly higher percentage of neutrophils in the BALF: median (interquartile range) 48 (14-82)% compared with 7 (0-16)% (p<0.025). A positive BALF culture was found in 62% of the infants with mucosal inflammation compared with 25% in the group without inflammation (p<0.016). 56% of the BALF samples were positive for bacterial culture. In children with persistent respiratory symptoms, nearly half have anatomical anomalies of the central airways. In 62% of the children with mucosal inflammation, a positive BAL culture and a significantly higher percentage of BALF neutrophils were detected.

Anaphylactic shock as a single presentation of Echinococcus cyst.

We describe the case of a 14-year-old boy of Turkish origin, presenting with anaphylactic shock after a minor abdominal trauma. Further investigations revealed a hepatic Echinococcal cyst without evidence of rupture. Anti-helminthic therapy was administered. Because of aggravating symptoms and recurrent anaphylaxis, surgical excision was performed. Intra-operative, a rupture into the biliary tree was seen. After surgery, the anaphylactic symptoms disappeared and the patient recovered. This case-report supports the fact that anaphylactic shock can be the only presentation of a hydatid cyst. Microscopic spillage can possibly be sufficient to cause major anaphylaxis.

Pseudomonas aeruginosa in the home environment of newly infected cystic fibrosis patients.

The source of acquisition of Pseudomonas aeruginosa in cystic fibrosis (CF) patients remains unknown. Patient-to-patient transmission has been well documented but the role of the environment as a source of initial infection is as yet unclear. In the present study, the origin of the first P. aeruginosa isolate in CF patients was investigated by comparing the P. aeruginosa genotype(s) from newly infected patients with genotypes of P. aeruginosa isolates from the home environment and from other patients from the same CF centre. A total of 50 newly infected patients were studied. P. aeruginosa could be cultured from 5.9% of the environmental samples, corresponding to 18 patients. For nine of these, the genotype of the environmental P. aeruginosa isolate was identical to the patient's isolate. In total, 72% of the environmental P. aeruginosa isolates were encountered in the bathroom. Patient-to-patient transmission within the CF centre could not be ruled out for three patients. In summary, a low prevalence of Pseudomonas aeruginosa was found in the home environment of the newly infected cystic fibrosis patients. The bathroom should be targeted in any preventive cleaning procedures. An environmental source of the new infection could not be ruled out in nine patients.

Epidemiology of Pseudomonas aeruginosa in a cystic fibrosis rehabilitation centre.

Pseudomonas aeruginosa is the leading pathogen in cystic fibrosis (CF) lungs. Since there is great concern about clonal spread in CF centres, this study examined the P. aeruginosa genotypes of colonised residents of a CF rehabilitation centre. The isolates from the sputum of 76 P. aeruginosa-colonised patients were genotyped by fluorescent amplified fragment length polymorphism on arrival and departure. A total of 71 different P. aeruginosa genotypes were identified from 749 isolates. Forty-nine patients had one genotype, 20 had two genotypes and seven had three. Forty-four patients had one or more genotypes in common with other patients (i.e. cluster types). Thirty-two patients were colonised by a single genotype not shared by any other patient. Thirty-eight of the 44 patients with a cluster type already carried their cluster type strain(s) on arrival. Patient-to-patient transmission could not be excluded for eight patients. For five of these, this infection was transient. None of the environmental P. aeruginosa isolates had a genotype similar to the patients' genotypes. In summary, most patients were colonised by only one or two P. aeruginosa genotypes and the risk of persistent patient-to-patient transmission was low during the study period (4%). Most patients with a cluster-type strain carried this strain on arrival, indicating that transmission could have happened in the past. No environmental contamination could be established.

Asphyxiating tracheal bronchogenic cyst.

We report on a 7-month old infant with severe respiratory distress secondary to a paratracheal bronchogenic cyst. Respiratory relief was achieved by transtracheal puncture of the cyst. Surgical removal of the cyst was performed 1 week later because of radiological evidence of reaccumulation of fluid.

Use of tissue type plasminogen activator in neonates: case reports and review of the literature.

Recombinant tissue type plasminogen activator (rt-PA) has been used successfully in neonates for resolution of thrombotic processes, both arterial and venous. We report on 2 neonates with vena cava inferior thrombosis and with biochemical evidence of liver dysfunction in whom rt-PA treatment had to be interrupted because of significant bleeding tendency, without complete resolution of the thrombus. Therapy failure may be due to the age of the thrombus and the systemic way of administration, bypassing the site of the thrombus by collateral circulation. Impaired liver function may result in decreased degradation of rt-PA with prolonged effect and higher risk for bleeding complications. We suggest that lower doses should be administered in these patients.