Andrea Spanò

Mass screening for coeliac disease using antihuman transglutaminase antibody assay

Aims: To determine coeliac disease prevalence by an anti-transglutaminase antibody assay in a large paediatric population; to evaluate acceptance of the screening programme, dietary compliance, and long term health effects. Methods: Cross-sectional survey of 3188 schoolchildren (aged 6–12) and prospective follow up of diagnosed cases. Main outcome measures were: prevalence of coeliac disease defined by intestinal biopsy or positivity to both human tissue transglutaminase and anti-endomysium antibodies in HLA DQ2-8 positive subjects; percentage of children whose families accepted screening; dietary compliance as defined by negativity for anti-transglutaminase antibodies; and presence of clinical or laboratory abnormalities at 24 month follow up. Results: The families of 3188/3665 children gave their consent (87%). Thirty biopsy proven coeliacs were identified (prevalence 1:106). Three other children testing positive for both coeliac related autoantibodies and HLA DQ2-8 but refusing biopsy were considered as having coeliac disease (prevalence 1:96). Of 33 cases, 12 had coeliac related symptoms. The 30 biopsy proven coeliacs followed a gluten-free diet. Of 28 subjects completing 18–24 months follow up, 20 (71.4%) were negative for anti-transglutaminase antibodies, while eight were slightly positive; symptoms resolved in all 12 symptomatic children. Conclusions: Prevalence of coeliac disease is high in Italian schoolchildren. Two thirds of cases were asymptomatic. Acceptance of the programme was good, as was dietary compliance. Given the high prevalence and possible complications of untreated coeliac disease, the availability of a valid screening method, and evidence of willingness to comply with dietary treatment population mass screening deserves careful consideration.

Polymorphisms in the MBL2 promoter correlated with risk of HIV-1 vertical transmission and AIDS progression

We investigated the polymorphisms of the promoter region of the MBL2 gene, which codifies for the Mannose-binding protein (MBP). The study population included 90 children with vertically acquired HIV-infection, further divided on the basis of the disease rate, 27 HIV exposed-uninfected children, and 74 healthy control subjects matched for ethnic origin to evaluate the MBP involvement in the risk of HIV-1 infection and to assess the role of the MBP promoter in AIDS progression. A region of 380 bp in the promoter of the MBL2 gene was analysed by PCR and direct sequencing of both DNA strands. We found that the polymorphism at position −550 influences the risk of HIV-infection and AIDS progression. Also a 6 bp deletion at position −328 was correlated with HIV-1 infection. This study indicates that the promoter of the MBL2 gene influences vertical transmission of HIV and the course of perinatal infection.

A reliable screening procedure for coeliac disease in clinical practice.

Background: The main autoantigen recognized by the sera of patients with coeliac disease (CD) is tissue transglutaminase (tTG). A human-recombinant form of tTG was used to develop an ELISA to measure anti-tTG serum antibodies for the diagnosis of CD. Preliminary retrospective reports suggest that the human tTG-based ELISA could identify coeliac patients missed by the IgA-anti-endomysium antibody test (AEA). Whether the human recombinant tTG ELISA is sufficiently accurate to become the main diagnostic CD tool in everyday clinical practice is unknown. The objective was to determine, in a prospective study, the sensitivity and specificity of an ELISA test based on the use of human tTG compared with AEA, to analyse the discordant cases for HLA DQ2-8 and for clinical and intestinal biopsy characteristics. Methods: 1106 patients referred to a gastrointestinal outpatient clinic for symptoms attributable to CD, 52 first-degree relatives of CD patients and 200 healthy controls were tested for both anti-human tTG and AEA antibodies. Results: Out of 1158 subjects, 146 were tested positive for anti-tTG antibodies and 140 were biopsy-proven coeliacs. The AEA test identified 126/1158 coeliacs who also tested positive for anti-tTG antibodies. The 14 patients missed by the AEA test carried the typical HLA-DQ for CD; they had normal levels of total serum IgA and had milder pathology than those with both anti-tTG and AEA positivity ( P < 0001). Conclusions: These results prove that human tTG-based ELISA is an excellent diagnostic tool for CD, for mass screening by both the specialist and the general clinic.

Celiac disease in patients with sporadic and inherited cardiomyopathies and in their relatives

AIMS To investigate celiac disease (CD) and related co-morbidity in patients with familial and sporadic cardiomyopathy and in their relatives. METHODS AND RESULTS We screened anti-human-tissue-transglutaminase (IgA and IgG anti-h-tTG) and anti-endomysial antibodies (AEAs) in 238 consecutive adult patients with inherited or sporadic dilated cardiomyopathy (DCM), 418 relatives, and 2000 healthy blood donors. HLADQ2-DQ8 was tested in tTG-positive subjects. The IgA-tTG-positive patients with cardiomyopathy underwent duodenal biopsy. Twenty-six subjects were tTG-positive: five DCM patients (2.1%), two of 28 (7.1%) and three of 390 (0.7%) relatives with and without echocardiographic abnormalities respectively, and 16 controls (0.8%). Twenty-two of 26 subjects were AEA-positive, and 25 HLA-positive. Of the five patients with cardiomyopathy and biopsy-proven CD, four suffered iron-deficiency anaemia. Two CD-positive DCM patients and two tTG-positive relatives were from families with inherited disease in which CD did not co-segregate with DCM. CONCLUSIONS; The higher prevalence of CD in patients with sporadic or inherited DCM, and of tTG-positive serology in relatives with echocardiographic abnormalities, suggests that immune-mediated mechanisms are active in subsets of patients/families. However, gluten intolerance cannot be considered causative since CD seems to be associated but not co-segregated with DCM in familial cases.

Variant mannose-binding lectin alleles are associated with celiac disease

Abstract. In this study, we investigated the role of mannose-binding lectin (MBL) in celiac disease, by performing genotype analysis for the three point mutations in the first exon of the gene in 117 Italian celiac patients (characterized by flat biopsy and positive for anti-endomysium antibody and human transglutaminase antibodies) and 130 pan-ethnic healthy controls. The frequency of homozygous mutant 0/0 was significantly higher in the 117 Italian celiac patients (0.13) than in the 130 pan-ethnic healthy controls (0.05; P=0.0405). An increased frequency of homozygous 0/0 allele was found among patients with celiac disease compared with controls. These results suggest an involvement of MBL in the pathophysiology of celiac disease.

Fluorescent RT in situ PCR detection of MRP1 mRNA in human HCV infected liver.

Chronic hepatitis C is now a major cause of chronic liver disease, cirrhosis and hepatocellular carcinoma. Approximately 20% of cases of acute viral hepatitis are due to hepatitis C. Cirrhosis develops in more than 25% of patients with chronic infection and each year hepatocellular carcinoma occurs in 1-3% of patients with cirrhosis due to HCV (Hoofnagle 1999). Patients with hepatocellular carcinoma are characterized by nonresponsiveness to chemotherapeutic agents. A cause of refractivity to treatment has been ascribed to the overexpression of the Pgp (MDR) protein (Kim et al. 1999), and the additional involvement of multidrug resistance-associated proteins (MRPs) has been also hypothesized (Minemura et al. 1999).

Detection of AGXT gene mutations by denaturing high-performance liquid chromatography for diagnosis of hyperoxaluria type 1

Abstract Primary hyperoxaluria type 1 is an autosomal recessive disorder of glyoxylate metabolism, caused by a deficiency of alanine:glyoxylate aminotransferase, which is encoded by a single copy gene (AGXT). The aim of this research was to standardize denaturing high-performance liquid chromatography, a new, sensitive, relatively inexpensive, and automated technique, for the detection of AGXT mutation. Denaturing high-performance liquid chromatography was used to analyze in blind the AGXT gene in 20 unrelated Italian patients with primary hyperoxaluria type 1 previously studied by other standard methods (single-strand conformation polymorphism analysis and direct sequencing) and 50 controls. Denaturing high-performance liquid chromatography allowed us to identify 13 mutations and the polymorphism at position 154 in exon I of the AGXT gene. Hence the method is more sensitive and less time consuming than single-strand conformation polymorphism analysis for the detection of AGXT mutations, thus representing a useful and reliable tool for detecting the mutations responsible for primary hyperoxaluria type 1. The new technology could also be helpful in the search for healthy carriers of AGXT mutations amongst family members and their partners, and for screening of AGXT polymorphisms in patients with nephrolithiasis and healthy populations.