Development of a novel SNP assay to detect lactase persistence associated genetic variants.

BACKGROUND: In adulthood the activity of the lactase enzyme is inherited as autosomal dominant form associated to Single nucleotide polymorphisms (SNPs). The present research was aimed to develop a novel genetic method to test lactase non persistence more powerfully. METHODS AND RESULTS: In our study, we selected eight different SNPs that are associated with lactase persistence from Caucasian, Arabian Bedouins, sub-Saharian Africans and Asian populations to set up an approach to detect all the eight different SNPs at the same time in the same sample. This technique is centred on the identification of SNPs with a single nucleotide primer extension method using Sanger sequencing and capillary electrophoresis. CONCLUSIONS: Our method allowed us to check the genotype asset of eight SNPs related to lactase persistence simultaneously and in a very efficient manner. It could be applied to a higher number of SNPs in a single reaction.

Celiac disease in pediatric patients according to HLA genetic risk classes: a retrospective observational study.

BACKGROUND: Celiac disease (CD) is an autoimmune enteropathy in which HLA-DQ haplotypes define susceptibility. Our aim was to evaluate if belonging to a certain HLA-DQ class risk could be associated to the clinical, serological and histological presentation of CD. METHODS: We performed a retrospective observational monocentric study including all 300 patients diagnosed with CD, who underwent HLA typing. Clinical, serological and histological data was collected from clinical records and their association with HLA-DQ class risk was verified through statistical tests. RESULTS: In our sample mean age at onset was 6.7 ± 4.2 years, with a prevalence of females (n = 183; 61%), typical symptoms (n = 242; 80.6%) and anti-tTG IgA ≥ 100 U/mL (n = 194; 64.7%). Family history was present only in 19% (n = 57) of patients, and it was not significantly associated with any of the clinical and demographical data analyzed or the belonging to a certain HLA-DQ class risk. We found in the male population more frequently a coexistence of CD and atopic syndrome (males: n = 47; 40.2%; females: n = 50; 27.3%; p = 0.020). Early age of onset, instead, was associated with typical symptoms (m = 6.4 ± 4; p = 0.045) and elevated liver enzymes (m = 5 ± 3.8; p < 0.001), while later age of onset was associated with presence of other autoimmune diseases (m = 8.2 ± 4; p = 0.01). We observed statistically significant influences of HLA class risk on antibodies and liver enzymes levels: G1, G4 and G2 classes showed more frequently anti-tTG IgA ≥ 100 U/mL (n = 44; 80%, n = 16; 69.6%, n = 48; 67.6% respectively; p-value = 0.037), and in patients from G2 class we found enhanced liver enzymes (n = 28; 39.4%; p-value = 0.005). HLA class risk was still significantly associated with anti-tTG ≥ 100 (p = 0.044) and with hypertransaminasemia (p = 0.010) after a multiple logistic regression adjusted for the effect of gender, age at onset and family history. CONCLUSIONS: We failed to prove an association between HLA-DQ genotypes and the clinical features in our CD pediatric patients. Although, our results suggest an effect of the DQB1-02 allele not only on the level of antibodies to tTG, but possibly also on liver involvement.

Congruency of Genetic Predisposition to Lactase Persistence and Lactose Breath Test.

The physiological decline of lactase production in adulthood, in some individuals, is responsible for the so-called "Lactose Intolerance." This clinical syndrome presents with gastrointestinal and non-gastrointestinal symptoms following the consumption of dairy containing food. Lactose intolerance can be evaluated by means of the Lactose Breath Test (phenotype) and/or genetic evaluation of lactase-gene polymorphism (genotype). A comparison of the two tests was carried out in a large number of symptomatic adult subjects, which are selected and not representative of the general population. Congruency was as high as 88.6%. Among lactase non-persistent (genotype C/C), 14 subjects showed a negative Lactose Breath Test (LBT), possibly due to young age. Among lactase-persistent (genotype C/T), four subjects showed a positive LBT, which helps to diagnose secondary lactose intolerance. Symptoms, both gastrointestinal and extra-gastrointestinal, were reported by 90% of patients during the breath test. Clinical use of both tests in the same patients could be taken into consideration as a sharp diagnostic tool. We suggest considering the use of the genetic test after LBT administration, when secondary hypolactasia is suspected, for completion of diagnostic procedures.

Correction: Metabolomic profiling and biochemical evaluation of the follicular fluid of endometriosis patients.

Correction for 'Metabolomic profiling and biochemical evaluation of the follicular fluid of endometriosis patients' by Marianna Santonastaso et al., Mol. BioSyst., 2017, DOI: 10.1039/c7mb00181a.

Intestinal Dysbiosis and Yeast Isolation in Stool of Subjects with Autism Spectrum Disorders.

High frequency of gastrointestinal yeast presence in ASD subjects was shown through a simple cultural approach (Candida spp. in 57.5 % of ASDs and no controls); the identification of aggressive form (pseudo-hyphae presenting) of Candida spp. at light microscope means that adhesion to intestinal mucosa is facilitated. Dysbiosis appears sustained by lowered Lactobacillus spp. and decreased number of Clostridium spp. Absence of C. difficilis and its toxins in both ASDs and controls is also shown. Low-mild gut inflammation and augmented intestinal permeability were demonstrated together with the presence of GI symptoms. Significant linear correlation was found between disease severity (CARs score) and calprotectin and Clostridium spp. presence. Also GI symptoms, such as constipation and alternating bowel, did correlate (multivariate analyses) with the increased permeability to lactulose. The present data provide rationale basis to a possible specific therapeutic intervention in restoring gut homeostasis in ASDs.

Antibodies against food antigens in patients with autistic spectrum disorders.

PURPOSE: Immune system of some autistic patients could be abnormally triggered by gluten/casein assumption. The prevalence of antibodies to gliadin and milk proteins in autistic children with paired/impaired intestinal permeability and under dietary regimen either regular or restricted is reported. METHODS: 162 ASDs and 44 healthy children were investigated for intestinal permeability, tissue-transglutaminase (tTG), anti-endomysium antibodies (EMA)-IgA, and total mucosal IgA to exclude celiac disease; HLA-DQ2/-DQ8 haplotypes; total systemic antibodies (IgA, IgG, and IgE); specific systemic antibodies: α-gliadin (AGA-IgA and IgG), deamidated-gliadin-peptide (DGP-IgA and IgG), total specific gliadin IgG (all fractions: α, ß, γ, and ω), ß-lactoglobulin IgG, α-lactalbumin IgG, casein IgG; and milk IgE, casein IgE, gluten IgE,-lactoglobulin IgE, and α-lactalbumin IgE. RESULTS: AGA-IgG and DPG-IgG titers resulted to be higher in ASDs compared to controls and are only partially influenced by diet regimen. Casein IgG titers resulted to be more frequently and significantly higher in ASDs than in controls. Intestinal permeability was increased in 25.6% of ASDs compared to 2.3% of healthy children. Systemic antibodies production was not influenced by paired/impaired intestinal permeability. CONCLUSIONS: Immune system of a subgroup of ASDs is triggered by gluten and casein; this could be related either to AGA, DPG, and Casein IgG elevated production or to impaired intestinal barrier function.

Alterations of the intestinal barrier in patients with autism spectrum disorders and in their first-degree relatives.

OBJECTIVES: Intestinal permeability (IPT) was investigated in patients with autism as well as in their first-degree relatives to investigate leaky gut hypothesis. Faecal calprotectin (FC) was also measured in patients with autism, either with or without gastrointestinal symptoms, and in their first-degree relatives. PATIENTS AND METHODS: IPT results, assessed by means of the lactulose/mannitol test, were compared with adult and child controls and with FC values. RESULTS: A high percentage of abnormal IPT values were found among patients with autism (36.7%) and their relatives (21.2%) compared with normal subjects (4.8%). Patients with autism on a reported gluten-casein-free diet had significantly lower IPT values compared with those who were on an unrestricted diet and controls. Gastrointestinal symptoms were present in 46.7% of children with autism: constipation (45.5%), diarrhoea (34.1%), and others (alternating diarrhoea/constipation, abdominal pain, etc: 15.9%). FC was elevated in 24.4% of patients with autism and in 11.6% of their relatives; it was not, however, correlated with abnormal IPT values. CONCLUSIONS: The results obtained support the leaky gut hypothesis and indicate that measuring IPT could help to identify a subgroup of patients with autism who could benefit from a gluten-free diet. The IPT alterations found in first-degree relatives suggest the presence of an intestinal (tight-junction linked) hereditary factor in the families of subjects with autism.

Defective synthesis of granulocyte-colony stimulating factor in pegylated interferon-alpha treated chronic hepatitis C patients with declining leukocyte counts.

BACKGROUND: Pegylated-interferon-alpha (peg-IFN-alpha) is the mainstay of treatment for chronic hepatitis C (CHC). Treatment is often complicated by neutropaenia due to inhibition of haematopoiesis. However, there are no data on the kinetics of granulocyte-colony stimulating factor (G-CSF), a major neutrophil growth factor, in this setting. We therefore evaluated G-CSF synthesis in CHC patients on peg-IFN-alpha treatment. METHODS: A total of 40 CHC patients were studied. None had pre-existing haematological disorders, or hepatitis B virus or HIV coinfection. For controls, 30 healthy subjects were used. Laboratory examinations, including liver function tests, were performed at baseline and monthly over treatment and follow-up. Serum G-CSF was measured in all patients and controls at baseline and in a subgroup of 20 CHC patients also at weeks 2, 4, 24, 48 and 72 after treatment start. RESULTS: CHC patients had a significantly lower pre-treatment neutrophil count (3,256 +/- 1,197 versus 3,804 +/- 859; P = 0.03). Notwithstanding, they showed lower baseline G-CSF serum levels than healthy controls (16.1 +/- 6.2 versus 19.4 +/- 7.5; P = 0.048). Consistently, baseline G-CSF levels were poorly correlated with the neutrophil count in CHC patients (r = -0.2; P = 0.2). Moreover, serum G-CSF levels did not increase in any of the 20 CHC patients during peg-IFN-alpha treatment, despite declining neutrophil counts. CONCLUSIONS: The lower neutrophil counts observed in CHC might be related to an absolute deficiency in G-CSF production. In the human model of neutropaenia induced by peg-IFN-alpha, we show that endogenous G-CSF levels are not physiologically up-regulated to overcome the decline in neutrophil counts. Our study provides a rationale for the evaluation of recombinant human G-CSF treatment in peg-IFN-alpha-induced neutropaenia.

Silent celiac disease in chronic hepatitis C: impact of interferon treatment on the disease onset and clinical outcome.

GOALS: To assess the impact of interferon treatment on celiac disease onset in hepatitis C patients and to clarify its clinical relevance and outcome. BACKGROUND: Hepatitis C is associated with autoimmunity, which can be exacerbated by interferon treatment. Cases of celiac disease activation during interferon treatment have been reported. STUDY: Retrospective evaluation of 534 hepatitis C patients with or without symptoms compatible with celiac disease onset during interferon treatment and 225 controls. Anti-transglutaminase antibodies were assayed. HLA-DQA1 and -B1 loci were typed. Upper gastrointestinal endoscopy was applied to confirm the diagnosis in antibody-positive patients. RESULTS: Anti-transglutaminase antibodies were detected before treatment in 1.3% of hepatitis C patients and in 0.4% of controls (not significant). Eighty-six percent of patients with anti-transglutaminase antibodies showed activation of celiac disease while on interferon. Symptoms ranged from mild to severe, and interferon had to be discontinued in 2 of 7 (29%) patients. Symptoms disappeared in 6 of 7 patients after interferon withdrawal. Onset of symptoms compatible with celiac disease during interferon therapy was significantly associated with the presence of anti-transglutaminase antibodies (OR 53). CONCLUSIONS: In hepatitis C patients, the activation of silent celiac disease during interferon treatment is almost universal and should be suspected, but it uncommonly requires interferon treatment discontinuation. Symptoms subside after interferon withdrawal.