A Functional Idiotype/Anti-Idiotype Network Is Active in Genetically Gluten-Intolerant Individuals Negative for Both Celiac Disease-Related Intestinal Damage and Serum Autoantibodies.

An unbalance between Abs that recognize an autoantigen (idiotypes; IDs) and Igs that bind such Abs (anti-IDs) is considered a functional event in autoimmune disorders. We investigated the presence of an ID/anti-ID network in celiac disease (CD), a condition in which antitissue transglutaminase 2 (TG2) Abs are suspected to contribute to CD pathogenesis. To characterize the ID side, we reproduced by in vitro yeast display the intestine-resident Abs from CD and control patients. These TG2-specific IDs were used to identify potential anti-IDs in the serum. We observed elevated titers of anti-IDs in asymptomatic patients with predisposition to CD and demonstrated that anti-ID depletion from the serum restores a detectable humoral response against TG2. Our study provides an alternative approach to quantify CD-related autoantibodies in cases that would be defined "negative serology" with current diagnostic applications. Therefore, we suggest that developments of this technology could be designed for perspective routine tests.

Mental health problems in children admitted with physical symptoms.

The aim of the study was to investigate the burden of mental health problems in children and adolescents admitted to a pediatric ward with physical complaints. We conducted a retrospective study, considering all patients admitted to the pediatric ward of the IRCCS Burlo Garofolo, Trieste, Italy, between January 2015 and September 2016. We selected all patients, from 5 to 17 years old, who were admitted with physical complaints and were discharged with a diagnosis suggestive of a mental health problem: somatic symptom disorder, anxiety disorder, depressive disorder, factious disorders. For every patient, we collected demographic features, medical characteristics, health care services utilization, length of hospital stay, and after discharge referral. We selected 1456 patients; of these, 101 (6.9%) revealed a mental health problem. The median duration of symptoms was 5 months (IQR 1.5-12), and pain was the main reported symptom (69%). Of the 101 patients, 23 (23%) were affected by a previously documented chronic organic disease. Somatic symptom disorder was the most common diagnosis. In 69/78 patients (88%), a loss of social contacts emerged; 49/95 patients frequenting school (51%) had chronic school absenteeism in the previous school year.Conclusion: A considerable proportion of patients admitted to a pediatric ward with physical complaints have mental health problems. What is Known: • It has been suggested that mental health problems in children and adolescents are increasing and frequently burden on pediatric healthcare services, but how they impact on a general pediatric ward is not clear. What is New: • Among 1456 patients admitted to a general pediatric ward with physical symptoms, 101 patients (6.9%) had a mental health problem. Among them, pain was the most commonly reported symptom and somatic symptom disorder was the commonly reported diagnosis.

PACSIN2 rs2413739 influence on thiopurine pharmacokinetics: validation studies in pediatric patients.

The aim of the study was to validate the impact of the single-nucleotide polymorphism rs2413739 (T > C) in the PACSIN2 gene on thiopurines pharmacological parameters and clinical response in an Italian cohort of pediatric patients with acute lymphoblastic leukemia (ALL) and inflammatory bowel disease (IBD). In ALL, PACSIN2 rs2413739 T allele was associated with a significant reduction of TPMT activity in erythrocytes (p = 0.0094, linear mixed-effect model, multivariate analysis considering TPMT genotype) and increased severe gastrointestinal toxicity during consolidation therapy (p = 0.049). A similar trend was present also for severe hematological toxicity during maintenance. In IBD, no significant effect of rs2413739 could be found on TPMT activity, however azathioprine effectiveness was reduced in patients carrying the T allele (linear mixed effect, p = 0.0058). In PBMC from healthy donors, a positive correlation between PACSIN2 and TPMT protein concentration could be detected (linear mixed effect, p = 0.045). These results support the role of PACSIN2 polymorphism on TPMT activity and mercaptopurine adverse effects in patients with ALL. Further evidence on PBMC and pediatric patients with IBD supports an association between PACSIN2 variants, TPMT activity, and thiopurines effects, even if more studies are needed since some of these effects may be tissue specific.

Acute rheumatic fever prophylaxis in high-income countries: clinical observations from an Italian multicentre, retrospective study.

OBJECTIVES: The aim of the study is to evaluate the compliance rate to secondary prophylaxis and the presence of rheumatic heart disease (RHD) in a cohort of Italian patients with acute rheumatic fever (ARF). METHODS: This is a multicentre retrospective study. The patients were divided into two groups by the presence or absence at last follow-up of RHD. Clinical features, ARF recurrences and the rate of compliance to secondary prophylaxis were evaluated. RESULTS: Two-hundred and ninety patients were enrolled (137 females; 153 males). Carditis at onset was present in 244 patients (84.7%). At the end of follow-up, 173 patients manifested RHD. Adherence to secondary prophylaxis was low in 26% of patients. The presence of RHD at follow-up was associated with the presence of carditis and its severity at onset (p=0.001), but it was not related to secondary prophylaxis adherence (p=NS). No association between prophylaxis adherence and ARF recurrence was found (p=NS) nor between ARF recurrence and RHD at the end of follow-up (p=NS). CONCLUSIONS: Poor adherence to secondary prophylaxis does not seem to be associated with increased risk of RHD in developed countries. Further studies are needed to confirm our data in a larger population.

Changing Epidemiology of Liver Involvement in Children With Celiac Disease.

OBJECTIVES: Available data indicate that liver involvement is present in a significant proportion of children with celiac disease (CD) at the diagnosis (elevated transaminases 15%-57%, autoimmune liver disease 1%-2%). We sought to evaluate prevalence, clinical course, and risk factors for liver involvement in a large cohort of children with CD. METHODS: Children (age 0-18 years) diagnosed with CD from March 2010 to April 2016 were enrolled. Liver involvement was considered to be present when alanine transaminase (ALT) levels were >40 U/L (hypertransaminasemia [HTS]). Patients with HTS were re-evaluated after at least 12 months of a gluten-free diet. RESULTS: CD was diagnosed in 806 patients during the study period; of these, ALT levels were available for 700 patients (86.9%), and were elevated in 27 (3.9%, HTS group); median ALT and aspartate transaminase levels in the HTS group were 57 U/L (interquartile range 49-80 U/L) and 67 U/L (interquartile range 53-85 U/L), respectively. Younger age, malabsorption symptoms, and low hemoglobin or ferritin were significantly more common in the HTS group at univariate analysis. At multivariate analysis, only age ≤4.27 years correlated with risk of liver involvement (odds ratio 3.73; 95% confidence interval: 1.61-8.66). When retested on a gluten-free diet, all but 3 patients normalized ALT levels; of these, 1 was diagnosed with sclerosing cholangitis. CONCLUSIONS: Liver involvement in celiac children is now less frequent than previously reported, possibly due to changing CD epidemiology. Younger age is the only risk factor. Associated autoimmune liver disease is rare.

Determination of Serum Infliximab Concentration by Point-of-care Devices in Children With Inflammatory Bowel Disease.

OBJECTIVES: Therapeutic drug monitoring is becoming increasingly important in clinical decision-making in children with inflammatory bowel disease (IBD). However, enzyme-linked immunosorbent assay (ELISA) assays do not allow results to be provided in real-time. We sought to compare 2 point-of-care (POC) devices for quantification of serum infliximab concentration with 2 validated ELISA assays in children with IBD. METHODS: We studied 32 serum samples from 19 children with IBD treated with infliximab. Serum samples were collected immediately before drug infusion (trough level). Infliximab was measured using 2 POC infliximab assays, Quantum Blue (POC IFX/QB) and Rida Quick (POC IFX/RQ), and 2 ELISA assays: Lisa-Tracker (used as primary reference), and Promonitor (used as second control). Intraclass correlation coefficient (ICC) was assessed for quantitative comparison. Qualitative analysis was also performed to evaluate whether POC assays would correctly classify infliximab serum according to a target window (between 3 and 7 µg/mL). RESULTS: ICC was 0.82 and 0.87 for POC IFX/QB and POC IFX/RQ with the primary reference ELISA assay, respectively; ICC between the 2 ELISA assays was 0.87. Classification of results according to therapeutic intervals showed good agreement between pairs of assays, with kappa of 0.67 and 0.80 for POC IFX/QB and POC IFX/RQ, respectively, with reference ELISA, and 0.81 between the 2 ELISAs. Accuracy of POC assays was better for drug levels <3 µg/mL. CONCLUSIONS: POC infliximab assays showed good agreement with traditional ELISA assays. POC devices may represent a viable option for real-time therapeutic drug monitoring in children treated with infliximab.

Causes of Treatment Failure in Children With Inflammatory Bowel Disease Treated With Infliximab: A Pharmacokinetic Study.

OBJECTIVES: Anti-tumor necrosis factor antibodies have led to a revolution in the treatment of inflammatory bowel diseases (IBD); however, a sizable proportion of patients does not respond to therapy. There is increasing evidence suggesting that treatment failure may be classified as mechanistic (pharmacodynamic), pharmacokinetic, or immune-mediated. Data regarding the contribution of these factors in children with IBD treated with infliximab (IFX) are still incomplete. The aim was to assess the causes of treatment failure in a prospective cohort of pediatric patients treated with IFX. METHODS: This observational study considered 49 pediatric (median age 14.4) IBD patients (34 Crohn disease, 15 ulcerative colitis) treated with IFX. Serum samples were collected at 6, 14, 22 and 54 weeks, before IFX infusions. IFX and anti-infliximab antibodies (AIA) were measured using enzyme linked immunosorbent assays. Disease activity was determined by Pediatric Crohn's Disease Activity Index or Pediatric Ulcerative Colitis Activity Index. RESULTS: Clinical remission, defined as a clinical score <10, was obtained by 76.3% of patients at week 14 and by 73.9% at week 54. Median trough IFX concentration was higher at all time points in patients achieving sustained clinical remission. IFX levels during maintenance correlated also with C-reactive protein, albumin, and fecal calprotectin. After multivariate analysis, IFX concentration at week 14 >3.11 µg/mL emerged as the strongest predictor of sustained clinical remission. AIA concentrations were correlated inversely with IFX concentrations and directly with adverse reactions. CONCLUSIONS: Most cases of therapeutic failure were associated with low serum drug levels. IFX trough levels at the end of induction are associated with sustained long-term response.

Somatic symptom disorder should be suspected in children with alleged chronic Lyme disease.

We report a case series of seven children admitted to a tertiary level pediatric ward for long-lasting physical symptoms with a previous diagnosis of chronic Lyme disease. In these children, medical history and clinical features were strongly suggestive of a psychopathological disorder, mainly a somatic symptom disorder. What is Known: • There is an increasing number of diagnoses of chronic Lyme disease both in North America and in Europe. Adults receive this diagnosis to explain chronic physical complaints often with negative history and serology. What is New: • Somatic symptom disorder should be suspected in children and adolescents with non-specific symptoms diagnosed with chronic Lyme disease.

Retrospective study showed that palpitations with tachycardia on admission to a paediatric emergency department were related to cardiac arrhythmias.

AIM: This retrospective study reviewed the prevalence and long-term prognosis of children aged 0-18 with palpitations who were admitted to the emergency department (ED) of an Italian paediatric hospital. METHODS: We examined all admissions to the ED of the IRCCS Burlo Garofolo between January 2009 and December 2015 by selecting triage diagnoses of palpitations. The hospital discharge cards were reviewed to assess vital parameters, physical examinations, diagnostic tests, cardiology consultations and final diagnoses. RESULTS: Of the 142 803 patients who attended our ED for any reason, 96 (0.07%) complained of palpitations. Despite this low prevalence, it was noteworthy that 13.5% had a real underlying arrhythmic cause and needed medical assistance. Over half (52.1%) were women and the mean age was 12.7 years. At the long-term follow-up, at a mean of 47 ± 23 months, 53.8% of patients with a cardiac arrhythmia had received medical therapy and 46.1% had undergone trans-catheter ablation for supraventricular tachycardia. A heart rate above 146 beats per minute or palpitations for more than an hour was statistically related to a cardiac arrhythmia. CONCLUSION: Palpitations were an infrequent cause of admission to our ED, but 13.5% who displayed them had an underlying cardiac arrhythmia.

A novel approach based on low-field NMR for the detection of the pathological components of sputum in cystic fibrosis patients.

PURPOSE: Development of a reliable, simple method to monitor lung condition in cystic fibrosis (CF) patients. Lung functionality assessment in CF patients is relevant, as most of them still die of respiratory failure. In lung mucus (sputum) of CF patients, components such as proteins, biopolymers, DNA, bacteria, and mucin are pathologically increased. As lung functionality is related to the amount of the pathological components in the sputum, their determination can help clinicians in monitoring lung condition and planning therapy. METHODS: Low-field NMR was used to evaluate the variation of the relaxation time (T2m ) of the water hydrogens present in CF sputum in relation to the amounts of the pathological components. Low-field NMR was tested in artificial samples (mucin or alginates), then in conditional sputum (saliva from healthy volunteers, added by different amounts of the pathological components), and finally in 12 patients' sputums, in which T2m was correlated to a commonly used lung monitoring test (i.e., forced expiratory volume in the first second). RESULTS: T2m significantly (P < 0.05) differed between samples with and without pathological components and between healthy and CF patients (P < 0.05), in which T2m correlated (r = 0.87) with FEV1 . CONCLUSIONS: The presented method can potentially become a valuable lung-monitoring tool in CF patients. Magn Reson Med 79:2323-2331, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Immunohistologic analysis of the duodenal bulb: a new method for celiac disease diagnosis in children.

BACKGROUND AND AIMS: Anti-tissue transglutaminase antibodies (anti-tTG) have simplified celiac disease (CD) diagnosis. However, in atypical forms of CD, intestinal biopsy sampling is still required. This prospective study investigates whether histologic analysis of the duodenal bulb combined with intestinal IgA anti-tTG deposit immunoassay makes CD diagnosis possible in at-risk children with low concentrations of serum anti-tTG. METHODS: Histologic and intestinal IgA anti-tTG deposit immunoassays were used. RESULTS: Two hundred forty-five symptomatic children positive for serum anti-tTG (>7 U/mL) were enrolled and divided into 3 groups: extensive duodenal atrophy (n = 209), with IgA anti-tTG deposits throughout the duodenum and high serum anti-tTG concentrations (157 ± 178 U/mL); bulb duodenal atrophy (n = 22), with widespread IgA anti-tTG deposits in 9 and in the bulb alone in 13 and low serum anti-tTG concentrations (13.9 ± 8.7 U/mL); and normal duodenum (n = 14), with widespread IgA anti-tTG deposits in 8 and in the bulb alone in 6 and low serum anti-tTG concentrations (10.6 ± 6.2 U/mL). All patients in the first 2 groups were diagnosed with CD and 8 from the third group. All improved after 1 year of gluten-free diet. Bulb duodenal analysis led to a 12% (30/245) increase in CD diagnosis. No CD-related lesions were observed in the 30 control subjects. CONCLUSIONS: In children at risk for CD, bulb duodenum biopsy sampling is essential to identify villous atrophy and detect IgA anti-tTG deposits even in absence of intestinal lesions. These mucosal autoantibodies could well represent a new standard for diagnosing CD.

Anti-transglutaminase 6 Antibody Development in Children With Celiac Disease Correlates With Duration of Gluten Exposure.

OBJECTIVES: Antibodies against transglutaminase 6 (anti-TG6) have been implicated in neurological manifestations in adult patients with genetic gluten intolerance, and it is unclear whether autoimmunity to TG6 develops following prolonged gluten exposure. We measured the anti-TG6 in children with celiac disease (CD) at the diagnosis time to establish a correlation between these autoantibodies and the duration of gluten exposure. We investigated a correlation between anti-TG6 and the presence of neurological disorders. METHODS: Anti-TG6 (IgA/IgG) were measured by ELISA in sera of children with biopsy-proven CD and of children experiencing gastrointestinal disorders. CD patients positive for anti-TG6 were retested after 2 years of gluten-free diet (GFD). RESULTS: We analyzed the sera of 274 CD children and of 121 controls. Anti-TG6 were detected in 68/274 (25%) CD patients and in 19/121 (16%) controls, with significant difference between the 2 groups (P = 0.04). None of the CD patients and of the controls testing positive for anti-TG6 were experiencing neurological disorders. Eleven of 18 (61%) CD patients with other autoimmune diseases were positive for anti-TG6. In CD patients, a significant correlation between the gluten exposure before the CD diagnosis and anti-TG6 concentration was found (P = 0.006 for IgA; P < 0.0001 for IgG). After GFD anti-TG6 concentrations were significantly reduced (P < 0.001). No significant correlation was observed between anti-TG6 and anti-TG2 serum concentrations. CONCLUSIONS: Anti-TG6 are more prevalent in children with untreated CD in the absence of overt neurological disorders. The synthesis of the anti-TG6 is related to a longer exposure to gluten before the CD diagnosis, and the autoimmunity against TG6 is gluten dependent and disappeared during GFD.

High-Throughput Sequencing of microRNAs in Glucocorticoid Sensitive Paediatric Inflammatory Bowel Disease Patients.

The aim of this research was the identification of novel pharmacogenomic biomarkers for better understanding the complex gene regulation mechanisms underpinning glucocorticoid (GC) action in paediatric inflammatory bowel disease (IBD). This goal was achieved by evaluating high-throughput microRNA (miRNA) profiles during GC treatment, integrated with the assessment of expression changes in GC receptor (GR) heterocomplex genes. Furthermore, we tested the hypothesis that differentially expressed miRNAs could be directly regulated by GCs through investigating the presence of GC responsive elements (GREs) in their gene promoters. Ten IBD paediatric patients responding to GCs were enrolled. Peripheral blood was obtained at diagnosis (T0) and after four weeks of steroid treatment (T4). MicroRNA profiles were analyzed using next generation sequencing, and selected significantly differentially expressed miRNAs were validated by quantitative reverse transcription-polymerase chain reaction. In detail, 18 miRNAs were differentially expressed from T0 to T4, 16 of which were upregulated and 2 of which were downregulated. Out of these, three miRNAs (miR-144, miR-142, and miR-96) could putatively recognize the 3’UTR of the GR gene and three miRNAs (miR-363, miR-96, miR-142) contained GREs sequences, thereby potentially enabling direct regulation by the GR. In conclusion, we identified miRNAs differently expressed during GC treatment and miRNAs which could be directly regulated by GCs in blood cells of young IBD patients. These results could represent a first step towards their translation as pharmacogenomic biomarkers.

Endoscopic and Histologic Healing in Children With Inflammatory Bowel Diseases Treated With Thalidomide.

BACKGROUND & AIMS: Mucosal healing, determined by endoscopic evaluation, is one of the most important prognostic markers for patients with inflammatory bowel diseases. Findings from histologic evaluation, however, could complement findings from endoscopy in assessing mucosal responses to treatment. We analyzed long-term results of children treated with thalidomide to determine the association between clinical response and histology and endoscopy findings. METHODS: We collected data from 2 multicenter trials of 70 children with refractory Crohn's disease (CD) or ulcerative colitis (UC) (2-18 years old; ileocolonic or colonic disease) given thalidomide or placebo (NCT00720538). Clinical remission and clinical response at 8 weeks were defined as a pediatric CD activity index scores 10 points or lower and a decrease of at least 50% from baseline, respectively, for patients with CD; and as a pediatric UC activity index score below 10 and a decrease of at least 20 points from baseline, respectively, for patients with UC. Patients with a clinical response to 8 weeks' treatment with thalidomide underwent endoscopic examination with biopsy collection at study weeks 12 and 52. Severity of inflammation in patients with UC was assessed by Mayo score and in patients with CD by 4-grade system. Biopsies were assessed for signs of active inflammation, erosion or ulceration, and crypt abscesses and assigned a histologic score. RESULTS: Clinical remission was observed in 42 patients (60.0%) and clinical response in 45 patients (64.2%) at Week 8. At Week 52, a total of 38 patients (54.3%) were still in clinical remission or still had a clinical response; 29 patients (41.4%) had mucosal healing, defined as complete healing of erosions or ulcerations, and 20 patients (27.7%) had histologic healing, defined as complete absence of markers of inflammation. Of patients with clinical remission or clinical response, 75.3% also had mucosal healing and 52.6% also had histologic healing. The probability of achieving mucosal healing decreased significantly with increasing values of erythrocyte sedimentation rate (adjusted odds ratio, 0.96; 95% CI, 0.93-0.98; P = .006). CONCLUSIONS: In a long-term analysis of data from 2 clinical trials of pediatric patients with CD or UC, 52 weeks' treatment with thalidomide led to clinical remission in 54.3% of patients with ileocolonic or colonic disease; of these patients, 75.3% had mucosal healing and 52.6% also had histologic healing. Further studies are needed to determine how thalidomide therapy affects long-term progression of inflammatory bowel diseases. (ClinicalTrials.gov number NCT00720538).

Somatic symptom disorder was common in children and adolescents attending an emergency department complaining of pain.

AIM: The aim of this study was to quantify the prevalence of somatic pain in a paediatric emergency department (ED). METHODS: We conducted a prospective observational study using patients admitted to the ED of an Italian children's hospital between December 2014 and February 2015. We enrolled children aged 7-17 who turned up at the ED complaining of pain. Patients and parents were asked to fill in a questionnaire to allow the analysis of the patients' medical history and provide contact details for follow-up. We divided the enrolled patients into four groups: post-traumatic pain, organic pain, functional pain and somatic pain. The questionnaire was used to define pain characteristics and to generate an impairment score. RESULTS: Of the 713 patients who met inclusion criteria, 306 (42.9%) were enrolled in the study. Of these, 135 (44.0%) suffered from post-traumatic pain, 104 (34.0%) from organic pain, 41 (13.4%) from functional pain and 26 (8.6%) from somatic pain. Somatic pain patients had endured pain longer, had missed more school days and had suffered severe functional impairment. CONCLUSION: This study highlighted that somatic pain was a significant contributor to paediatric emergency room visits and should be suspected and diagnosed in children reporting pain.

Differential expression of GAS5 in rapamycin-induced reversion of glucocorticoid resistance.

This study evaluates the association between the long noncoding RNA GAS5 levels and the anti-proliferative effect of the glucocorticoid (GC) methylprednisolone (MP) alone and in combination with rapamycin in peripheral blood mononuclear cells (PBMCs) obtained from healthy donors. The effect of MP, rapamycin, and MP plus rapamycin was determined in 17 healthy donors by labelling metabolically active cells with [methyl-3H] thymidine and the expression levels of GAS5 gene were evaluated by real-time RT-PCR TaqMan analysis. We confirmed a role for GAS5 in modulating GC response: poor responders presented higher levels of GAS5 in comparison with good responders. Interestingly, when PBMCs were treated with the combination of rapamycin plus MP, the high levels of GAS5 observed for each drug in the MP poor responders group decreased in comparison with rapamycin (P value = 0.0134) or MP alone (P value = 0.0193). GAS5 is involved in GC resistance and co-treatment of rapamycin with GCs restores GC effectiveness in poor responders through the downregulation of the long noncoding RNA. GAS5 could be considered a biomarker to personalize therapy and a novel therapeutic target useful for the development of new pharmacological approaches to restore GC sensitivity.

Fecal Calprotectin: Diagnostic Accuracy of the Immunochromatographic CalFast Assay in a Pediatric Population.

BACKGROUND: Fecal calprotectin is a noninvasive marker for bowel diseases and it is high valuable to follow disease activity in Crohn's disease (CD) and ulcerative colitis (UC). In this study, we evaluated the diagnostic performance of the recently introduced immunochromatographic assay CalFast in comparison to the well-known ELISA tests for calprotectin assay to obtain a rapid diagnosis of bowel inflammation in pediatric patients. METHODS: CalFast was tested in parallel to the classic ELISA tests CalPrest and PhiCal (gold standards for the calprotectin determination) on 148 fecal samples from pediatric subjects including 104 healthy subjects, 29 with CD, and 15 with UC. RESULTS: In this study, the sensitivity and specificity of CalFast, CalPrest, and PhiCal were 86.4%, 88.6%, and 93.2% and 86.6%, 74%, and 64.4%, respectively. The area under the curve, obtained from receiver operating characteristic analysis, indicated the lack of significant difference among all the kits used. CONCLUSION: The immunochromatographic assay demonstrated good diagnostic predictive values, comparable to those of the ELISA methods, and may represent a valid alternative in order to save operators' time. The test, in fact, has a short turnaround time and does not need a specific ELISA instrumentation.

Splenic Infarction in Acute Infectious Mononucleosis.

BACKGROUND: The evaluation of a febrile patient with acute abdominal pain represents a frequent yet possibly challenging situation in the emergency department (ED). Splenic infarction is an uncommon complication of infectious mononucleosis, and may have a wide range of clinical presentations, from dramatic to more subtle. Its pathogenesis is still incompletely understood, yet it may be associated with the occurrence of transient prothrombotic factors. CASE REPORT: We report the case of a 14-year-old boy who presented with fever, sore throat, left upper quadrant abdominal pain, and splenomegaly, with no history of recent trauma. Laboratory tests revealed a markedly prolonged activated partial thromboplastin time and positive lupus anticoagulant. Abdominal ultrasonography showed several hypoechoic areas in the spleen consistent with multiple infarctions. Magnetic resonance imaging eventually confirmed the diagnosis. He was admitted for observation and supportive treatment, and was discharged in good condition after 7 days. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Spontaneous splenic infarction should be considered in the differential list of patients presenting with left upper quadrant abdominal pain and features of infectious mononucleosis; the diagnosis, however, may not be straightforward, as clinical presentation may also be subtle, and abdominal ultrasonography, which is often used as a first-line imaging modality in pediatric EDs, has low sensitivity in this scenario and may easily miss it. Furthermore, although treatment is mainly supportive, close observation for possible complications is necessary.

Role of oxidative stress mediated by glutathione-s-transferase in thiopurines' toxic effects.

Azathioprine (AZA), 6-mercaptopurine (6-MP), and 6-thioguanine (6-TG) are antimetabolite drugs, widely used as immunosuppressants and anticancer agents. Despite their proven efficacy, a high incidence of toxic effects in patients during standard-dose therapy is recorded. The aim of this study is to explain, from a mechanistic point of view, the clinical evidence showing a significant role of glutathione-S-transferase (GST)-M1 genotype on AZA toxicity in inflammatory bowel disease patients. To this aim, the human nontumor IHH and HCEC cell lines were chosen as predictive models of the hepatic and intestinal tissues, respectively. AZA, but not 6-MP and 6-TG, induced a concentration-dependent superoxide anion production that seemed dependent on GSH depletion. N-Acetylcysteine reduced the AZA antiproliferative effect in both cell lines, and GST-M1 overexpression increased both superoxide anion production and cytotoxicity, especially in transfected HCEC cells. In this study, an in vitro model to study thiopurines' metabolism has been set up and helped us to demonstrate, for the first time, a clear role of GST-M1 in modulating AZA cytotoxicity, with a close dependency on superoxide anion production. These results provide the molecular basis to shed light on the clinical evidence suggesting a role of GST-M1 genotype in influencing the toxic effects of AZA treatment.

Different presentations of mevalonate kinase deficiency: a case series.

OBJECTIVES: We aimed to raise awareness among paediatricians and physicians about this often misunderstood condition. METHODS: We discussed the clinical profiles associated with late or wrong diagnosis of mevalonate kinase deficency (MKD) in a single centre case series. RESULTS: We analysed the most common challenges and pitfalls that a clinician might face during the diagnostic process. Five main clinical profiles were characterised. CONCLUSIONS: We propose a new perspective on MKD, suggesting that the presentation of this disease can vary from patient to patient.