Epidemiology and geographical variation of myasthenia gravis in the province of Pavia, Italy.

BACKGROUND AND AIMS: Previous studies have reported a prevalence estimate of myasthenia gravis (MG) from 7.7 to 11.1 per 100,000 inhabitants in Europe. Moreover, the study of the geographical distribution of MG should be useful to generate specific hypotheses. The aims are to estimate MG prevalence and to investigate its geographical variation in a delimited area in Northern Italy. METHODS: The primary source of data was the MG database of the Neurological Institute of Pavia and all other sources of case collection in and outside the province. We adopted a Bayesian approach to analyze MG geographical variation within the finest geographical grid. RESULTS: We identified 119 live MG prevalent cases resident in the province of Pavia on December 31, 2008. The overall crude prevalence was 24 per 100,000 inhabitants. The Bayesian analysis identified a small cluster of higher MG prevalence in the northern area of the province. CONCLUSIONS: The estimated MG prevalence sets the province of Pavia among the high-risk areas. The identification of high/low MG risk areas deserves further investigation of genetic and environmental factors possibly related to a major risk of the disease in that area.

Type or extension of intestinal metaplasia and immature/atypical "indefinite-for-dysplasia" lesions as predictors of gastric neoplasia.

At present, no information exists on the neoplastic potential of the immature hyperproliferative and atypical lesions of the gastric mucosa, which have been recently labeled "indefinite for dysplasia." In addition, uncertainties still exist concerning the risk contribution of intestinal metaplasia (IM) type and extension, as well as Helicobacter pylori infection. In this study, 471 dyspeptic patients showing IM 10% or higher (median, 40; 25th-75th percentile, 20-60) in antral, angulus, or corpus endoscopic biopsies were submitted to repeated examinations (median, 3; 2-5) over 52 (26-85) months of follow-up, during which 44 neoplastic cases were recorded. IM extension, incomplete, sulfomucin-positive, or CAR5 antigen-positive IM; H pylori infection; and indefinite-for-dysplasia lesions (IDLs), as found at first examination, all showed significant neoplastic potential. However, only IDL, ongoing H pylori infection, and patient's age retained independent predictive power in a multivariate model. On the other hand, IM extension 20% or higher proved to be more sensitive as first screening parameter for identification of subjects with increased neoplastic risk. We suggest that patients with IM, when infected, should undergo H pylori eradication to reduce their cancer risk; only those bearing IDL or very extensive IM (which strongly correlates with IDL) should be followed up with endoscopies and biopsies.