Healthy Italian Subjects Research Articles

Stature estimation from scapular measurements by CT scan evaluation in an Italian population

This study evaluated the correlation between scapula size and stature and developed standard equations in order to estimate stature by CT scan evaluation. A total of 200 healthy Italian subjects (100 men and 100 women, mean age 64.2±12.8years) underwent thoracic CT scan evaluation during pulmonary screening in our department; we measured the stature of each patient with standard anthropometric instruments and then analyzed images to calculate the longitudinal scapular length (LSL) and the transverse scapular length (TSL). The correlation between stature and each parameter measured was analyzed by dividing the population into two groups, males and females, and was examined by simple regression analysis using Pearson's correlation coefficient (r). Each anthropometric variable showed a significant difference between males and females (p value <0.001). The correlation coefficients (r-values) were LSL=0.74 and TSL=0.51 in males and LSL=0.70 and TSL=0.48 in females. In both sexes the r-values showed a significant correlation between stature and LSL. Our study demonstrates that scapulae can be used for stature estimation; in our sample LSL was found to have a better correlation with stature then TSL. hm=4.247*LSL+93.74 and hf=4.031*LSL+92.38 are the formulae that provide the most accurate stature assessment in males and females respectively.

Small Amplicons High Resolution Melting Analysis (SA-HRMA) allows successful genotyping of acid phosphatase 1 (ACP1) polymorphisms in the Italian population

BackgroundThe ACP1 gene, encoding a low-molecular-weight phosphotyrosine phosphatase (LMW-PTP), has been suggested as a common genetic factor of several human diseases, including inflammatory and autoimmune diseases, favism and tumors. For this reason, the ACP1 enzyme has been investigated by case–control studies for decades. Initially based on protein electrophoresis, the ACP1 phenotype is now determined by DNA-based techniques. MethodsHere, we report a rapid optimized method which employs HRMA for ACP1 polymorphism identification, a molecular approach that we used to screen 80 healthy Italian subjects. ResultsHRMA proved particularly suitable for detecting ACP1 genotypes. In fact, HRMA results were 100% concordant with direct sequencing. In addition, ACP1 genotype frequency in the Italian population was in accordance with the literature [4% (*A/A), 36% (*A/B), 4% (*A/C), 50% (*B/B), 6% (*B/C)]. ConclusionsHRMA was found to be a simple, rapid, sensitive and low cost method potentially useful in research and diagnostic laboratories. Finally, use of small amplicons for the set-up allowed us a better optimization of HRMA. For this reason, we present such an approach as small amplicons high resolution melting analysis (SA-HRMA).Finally, ACP1 genotype frequency in the Italian population reported in this study may contribute to a better interpretation of ACP1 allelic frequency variation.

Health and ageing: A cross-sectional study of body composition

The aim of this work was to provide a complete profile of body composition (BC) in healthy subjects and to investigate age and gender-related differences by dual-energy X-ray absorptiometry (DXA) and its latest developments. Italian volunteers among blood donors were enrolled in 5 different age bands (from 18 to 70 years old) to reach the threshold of 25 males and 25 females per single band (total: 250 subjects). All non-obese subjects who satisfied selective inclusion criteria were measured for weight and height and submitted to DXA, to determine fat mass (FM), non-bone lean mass (LM), bone mineral content and density, at regional and whole-body level. Moreover, the assessment of android visceral FM was performed by a new software. A decrease in LM and increase in FM was observed with ageing, although the phenomenon was proved to be attenuated in women. The central and visceral redistribution of FM was also shown along lifetime, but women were not affected as men by this change. This paper is a report on the status of healthy Italian subjects in their adulthood, to be used as a reference for future investigations on physiology, pathological human conditions, and differences between countries.

NLRP1 polymorphisms in patients with asbestos-associated mesothelioma

BackgroundAn increasing incidence of malignant mesothelioma (MM) cases in patients with low levels of asbestos exposure suggests the interference of alternative cofactors. SV40 infection was detected, as co-morbidity factor, only in 22% of asbestos-MM patients from a North-Eastern Italy area. An additional mechanism of injury related to asbestos exposure in MM development has been recently associated to inflammatory responses, principally driven by interleukin (IL)-1 beta (ß) activated within the inflammasome complex.NLRP3 inflammosome has been described as the intracellular sensor for asbestos able to induce inflammasome activation and IL-1ß secretion while NLRP1 is expressed in lung epithelial cells and alveolar macrophages and contributes to the immune response and to survival/apoptosis balance. This study proposes to evaluate the impact of known NLRP3 and NLRP1 polymorphisms in the individual susceptibility to asbestos-induced mesothelioma in subjects from a hyperendemic area for MM.Methods134 Italian patients with diagnosis of mesothelioma due (MMAE, n=69) or not (MMAF, n=65) to asbestos, 256 healthy Italian blood donors and 101 Italian healthy subjects exposed to asbestos (HCAE) were genotyped for NLRP1 (rs2670660 and rs12150220) and NLRP3 (rs35829419 and rs10754558) polymorphisms.ResultsWhile NLRP3 SNPs were not associated to mesothelioma, the NLRP1 rs12150220 allele T was significantly more frequent in MMAE (0.55) than in HCAE (0.41) (p=0.011; OR=1.79) suggesting a predisponent effect of this allele on the development of mesothelioma. This effect was amplified when the NLRP1 rs2670660 allele was combined with the NLRP1 rs12150220 allele (p=0.004; OR=0.52).ConclusionAlthough NLRP3 SNPs was not involved in mesothelioma predisposition, these data proposed NLRP1 as a novel factor possibly involved in the development of mesothelioma.

Effect of Age, Family History of Prostate Cancer, Prostate Enlargement and Seasonality on PSA Levels in a Contemporary Cohort of Healthy Italian Subjects

We assessed the joint effect of age at enrollment, age at follow-up, family history of prostate cancer, prostate enlargement and seasonality on prostate-specific antigen (PSA) estimated through log-normal mixed-effects modeling in an Italian cohort of healthy, 45- to 65-year-old subjects over a 4-year period. The median ratio was used as the measure of effect. Median and mean baseline PSA were 0.78 (interquartile range: 0.41-1.50) and 1.27 (95% CI: 1.19-1.35) ng/mL, respectively. A similar median annual increase of 5.7% (95% CI: 4.8%-6.5%) was found for age at enrollment and age at follow-up. Individuals with moderate to severe prostate enlargement had a median PSA ratio of 1.040 (95% CI: 0.919-1.176) and 1.318 (95% CI: 1.128-1.539), respectively. Median ratios of 1.200 (95% CI: 0.026-1.404) and 1.300 (95% CI: 0.915-1.845), respectively, were computed for subjects with only one or more than one prostate-cancer-affected relatives. Regarding seasonality, the highest value was shown in summertime, the lowest in wintertime, and the resulting median ratio was 1.280 (95% CI: 1.117-1.468). Irrespective of age, baseline PSA was in most cases about 1.00 ng/mL with a yearly median variation of about 5% over a 4-year period. Indeed, prostate enlargement, prostate cancer family history and seasonality showed a remarkable impact on PSA measurement. This should be considered when counseling patients with a PSA history.

The p.A897KfsX4 frameshift variation in desmocollin-2 is not a causative mutation in arrhythmogenic right ventricular cardiomyopathy

Mutations in genes encoding desmosomal proteins have been reported to cause arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D), an autosomal-dominant disease characterised by progressive myocardial atrophy with fibro-fatty replacement. We screened 112 ARVC/D probands for mutations in desmocollin-2 (DSC2) gene and detected two different amino-acid substitutions (p.E102K, p.I345T) and a frameshift variation (p.A897KfsX4) in 7 (6.2%) patients. DSC2a variant p.A897KfsX4, previously reported as a p.E896fsX900 mutation, was identified in five unrelated probands. Four of them were found to carry one or two mutations in different ARVC/D genes. Unexpectedly, p.A897KfsX4 variation was also found in 6 (1.5%) out of 400 control chromosomes. In vitro functional studies showed that, unlike wild-type DSC2a, this C-terminal mutated protein was localised in the cytoplasm. p.A897KfsX4 variation affects the last five amino acids of the DSC2a isoform but not of DSC2b. In contrast with what we found in other human tissues, in the heart DSC2b is more expressed than DSC2a, suggesting that relative deficiency of DSC2a might be compensated by isoform b. In conclusion, DSC2 gene mutations are not frequently involved in ARVC/D. The p.A897KfsX4 variation, identified in several Italian healthy control subjects, which affects only one of the two DSC2 isoforms, may be considered a rare variant, though possibly affecting phenotypic expression of concomitant ARVC/D mutations.

Olfactory dysfunction in Parkinsonism caused by PINK1 mutations

Hyposmia is a common nonmotor feature of Parkinson's disease (PD) and has been variably detected in monogenic Parkinsonisms. To assess olfactory dysfunction in PINK1-related Parkinsonism, we evaluated olfactory detection threshold, odor discrimination, and odor identification in five groups of subjects: sporadic PD (n = 19), PINK1 homozygous (n = 7), and heterozygous (n = 6) parkinsonian patients, asymptomatic PINK1 heterozygous carriers (n = 12), and Italian healthy subjects (n = 67). All affected subjects and all healthy heterozygotes but one resulted hyposmic, with most patients in the range of functional anosmia or severe hyposmia. Detection threshold was more preserved and discrimination more impaired in patients with PINK1 mutations than in PD cases. Alterations of detection and discrimination were observed also in PINK1 asymptomatic heterozygotes. On the contrary, odor identification appeared to be mostly related to the disease status, as it was impaired in nearly all patients (including PD and PINK1 cases) and preserved in healthy heterozygotes. Our data indicate that olfactory dysfunction is common in PINK1 Parkinsonism and consists typically in defective odor identification and discrimination. A milder olfactory deficit, mostly involving discrimination, can be found in asymptomatic heterozygotes, possibly indicating an underlying preclinical neurodegenerative process.

Variations at the H-strand replication origins of mitochondrial DNA and mitochondrial DNA content in the blood of type 2 diabetes patients

Mitochondrial DNA (mtDNA) sequence variation in the segment of the D-loop region encompassing the initiation sites for replication and transcription was analyzed in the blood of 277 Italian type 2 diabetes patients and 277 Italian healthy subjects. Compared with the Cambridge Reference Sequence, diabetic patients show a slightly higher propensity to accumulate base changes in this region, with respect to controls, although no significant association can be established between any of the detected changes and the diabetic condition. Subjects, patients and controls, harbouring base changes at the replication origins (positions 57 and 151) and at position 58 were analyzed for mtDNA content. The mtDNA content increased three–four times only in the diabetic patients bearing the m.151C>T transition, whereas in those bearing the m.58T>C change the mtDNA content doubled, independently of the affiliation haplogroup. This result suggests that the m.151C>T transition and, to a lower extent, the m.58T>C might confer to the blood cells of diabetic patients the capability of increasing their mtDNA content, whereas the same transitions have no effect on control subjects.

PPARgamma Promoter Polymorphisms and Acute Coronary Syndrome

BackgroundPPARgamma (PPARg) is a nuclear transcription factor involved in the control of lipid and glucose homeostasis. Two PPARg common polymorphisms, Pro12Ala and 161C>T, have been found to be associated with cardiovascular disease. In this study, in addition to PPARg coding region, we looked for genetic variations in promoters and their association with acute coronary syndrome (ACS). MethodsWe studied 202 Italian patients with ACS, and 295 healthy Italian subjects by dHPLC (denaturing high-performance liquid chromatography), heteroduplex analysis and direct sequencing or RFLP (restriction fragment length polymorphism) analysis for screening mutations. ResultsWe identified 7 new and 2 already published polymorphisms in PPARg promoters. The C>T93695 (promoter 4) mutation showed significantly different genotype distribution and allele frequency between controls and ACS patients (p<0.001); the T allele conferred a protection against ACS at both univariate (OR: 0.45, 95% CI 0.29–0.69: p<0.001) and multivariate analysis adjusted for sex, age and traditional cardiovascular risk factors (OR: 0.44, 95% CI 0.25–0.76: p<0.005). Moreover, the 161C>T polymorphism allele frequency (p=0.03) and genotype distribution (p=0.015) resulted to be different in ACS group if compared to healthy controls. ConclusionsThe protective role of 93695C>T polymorphism in PPARg promoter in ACS suggests that PPARg genetic variants may affect the susceptibility to atherosclerotic diseases.

Twenty years after Spinnler and Tognoni: new instruments in the Italian neuropsychologist’s toolbox

The aim of this article is to review neuropsychological normative studies which - after Spinnler and Tognoni's monograph of 1987 - were done on healthy Italian adult subjects, and which either wholly or partially used the Equivalent Scores (ES) methodology proposed by Capitani et al. The independent norms settled for the same tests have been compared in order to point out their agreement, measured by Cohen's Kappa, which in most cases resulted either excellent or good (>0.7). Available tests have been classified and arranged to facilitate the most suitable choice for different clinical purposes. Moreover, a simple software program has been set up which adjusts and transforms raw scores into ES. As well as saving time and avoiding errors, this simple aid is likely to improve the quality and clarity of the communication of neuropsychological results.

Fatty acid profiles of blood lipids in a population group in Tibet: correlations with diet and environmental conditions.

The aim of this study was to compare blood fatty acid profiles of two population groups: Italian and Tibetan, differing with regard to ethnic, life style and environmental aspects. Additionally the collection of two staple foods provided the opportunity to analyze typical Tibetan dishes. A new, simple, rapid, and substantially non invasive method for fatty acid (FA) analysis of blood lipids was applied to healthy Italian (n=14) and Tibetan (n=13) subjects. Blood drops obtained from the ear lobe of Tibetans or the fingertip of Italians were adsorbed by a special strip of paper and processed for fatty acid analysis. The fatty acid profiles of the two groups are different, and environmental factors, such as dietary fats and altitudes of Milan, Italy (a low altitude site), and Lhasa, Tibet (a high altitude site) appear to contribute to these differences. More specifically, in Ti-betans higher levels of monounsaturated fatty acids, including the 22 and 24 carbon molecules, were found. This appears to be derived mainly from locally consumed fats (mustard seed oil), and are associated with lower levels of total polyunsaturated fatty acids and higher levels of selected omega 3 fatty acids, when compared to the Italians. These relatively higher levels of monounsaturated fatty acids may also indicate means of adaptation to local prooxidant conditions. The observed differences in blood fatty acid profiles in Tibetans vs. Italians appear to result both from dietary factors and adaptation to local environmental conditions such as the high altitude of the Tibetan location.

Health-related quality of life and subjective outcome after shoulder replacement for proximal humeral fractures

Shoulder replacement has increased exponentially in recent decades, and previous studies have documented the effectiveness of this procedure. Pain relief, physical functional level, and health-related quality of life, however, were often not assessed. To our knowledge, no published articles have assessed quality of life in shoulder replacement for fracture. The main purpose of this study was to assess the patient-relevant outcomes in patients who underwent shoulder replacement for proximal humeral fractures. Standardized quality of life and shoulder-specific, self-administered questionnaires were used. On the Medical Outcomes Study Short Form 36 Health Survey, as expected, we observed a lower score in the domain compared with healthy Italian subjects. A surprising finding was that in the General Health and Role-Emotional domains, our sample had a better picture than the healthy one, probably because patients had experienced severe trauma and major surgery previously. These data represent the first step toward the definition of outcome for this procedure. This study does not address the necessity of therapy, but if this were included in future publications, it might provide useful data for therapeutic recommendations.

Uteroglobin-related protein 1 gene −112G/A polymorphism and atopic asthma in Sicilian children

The secretory protein, uteroglobin-related protein 1 (UGRP1), is expressed mainly in the lung and trachea and recently has been implicated in asthma. The -112G to A transition in the promoter was reported to be associated with asthma in the Japanese population. However, this has not been replicated in other studies. The aim of this study was to find the association of the UGRP1 gene polymorphism with atopic asthma in the Sicilian population. We conducted a transmission disequilibrium test (TDT) in 73 trios identified through 113 pediatric patients being treated for asthma. A case-control study also was performed by comparing the 113 unrelated asthmatic children and 230 unrelated healthy Italian subjects (121 children and 109 adults). The -112 G/A polymorphism was genotyped by the polymerase chain reaction-restriction fragment length polymorphism method and direct sequencing. The TDT revealed that the -112A allele was not preferentially transmitted from the parents to asthmatic offspring (chi-square = 3.08; p = NS). Neither the presence of at least one A allele in an individual's genotype (sum of the G/A and A/A genotype) nor the -112A allele was more prevalent among the asthma subjects than among the control subjects. Our results suggest that the -112G/A polymorphism does not play a significant role in the genetic predisposition of the UGRP1 gene in atopic asthma in the Sicilian population.

HLA-Cw allele frequencies in northern and southern Italy

The evidence for HLA-Cw antigens' involvement in the modulation of the immune response in bone marrow transplantation, NK alloreactivity and the susceptibility and follow-up for different diseases has been growing in the recent years, but very few data on HLA-Cw distribution in healthy Italian subjects are available to date. This report presents an updated description of HLA-Cw frequencies in Italy, comparing data from the northern (Lombardia) and southern (Campania and Puglia) parts of the country. A total of 1101 healthy subjects of Italian origin were genotyped, and the results showed that HLA-Cw⁎04, Cw⁎07, Cw⁎12, and, in particular, Cw⁎0401, Cw⁎0701, Cw⁎1203, were the most frequent alleles found in all three regions analysed. Nevertheless, statistically significant differences were observed in Cw⁎07 distribution, which was more frequent in the southern than in the northern part of Italy (28.8% vs 22.4%; p=0.001; OR: 1.4; 95%CI: 1.14–1.73), and in Cw⁎12 distribution, which was more frequent in the north than the south (17.0% vs 12.4%; p=0.007, OR: 1.4; 95%CI: 1.10–1.91). These results, which give an improved pattern of distribution of HLA-Cw alleles in the Italian population, would be useful in bone marrow transplantation and anthropological studies. Moreover, due to the important role of HLA-Cw antigens in modulation of the immune response and NK alloreactivity, these data would be of interest in studies on susceptibility, follow-up and/or protection against different diseases.

Fish intake and LPA 93C>T polymorphism: Gene-environment interaction in modulating lipoprotein (a) concentrations

High plasma lipoprotein (a) [Lp(a)] concentrations are an independent risk factor for atherosclerotic diseases. To date, no effective intervention strategies on reducing Lp(a) concentrations have been reported. The aim of the study was to evaluate the possible modulation of two polymorphisms of LPA gene ( LPA 93C>T and LPA 121G>A) and nutritional habits on Lp(a) concentrations. We studied 647 healthy Italian subjects (260 M; 387 F) with a median age of 48 years (range: 19–78) enrolled in an epidemiological study conducted in Florence, Italy. A linear regression analysis showed a significant negative influence of fish intake ( β = −0.174 ± 0.084; p = 0.04) on Lp(a) concentrations, after adjustment for smoking habit, C-reactive protein serum concentrations, dietary habits and LDL-cholesterol concentrations. With regard to LPA polymorphisms, LPA 93C>T polymorphism resulted to significantly affect Lp(a) circulating concentrations in a dose-dependent manner, with lower concentrations shown by subjects carrying the T rare allele, whereas no significant influence of LPA 121G>A polymorphism on Lp(a) concentrations was observed. Moreover, by analyzing the possible interplay between LPA 93C>T and dietary fish intake, a significant interaction between these two determinants in lowering Lp(a) concentrations was reported. In addition, lower Lp(a) concentrations were observed in subjects carrying the T allele of the LPA 93C>T polymorphism and consuming a high intake of fish with respect to those being in the highest tertile of fish consumption but homozygotes for the common allele of the polymorphism. In conclusion, this study reported a significant interaction of daily fish intake and LPA 93C>T polymorphism in decreasing Lp(a) concentrations.

Role of VEGF gene variability in longevity: A lesson from the Italian population

Vascular endothelial growth factor (VEGF) gene polymorphisms have been associated with an increased risk of developing a wide variety of disorders from diabetes to neurodegenerative diseases suggesting functions not confined to its vascular effects originally described. Based on the VEGF protective roles undisclosed in pathological conditions, we evaluate whether VEGF variability might be a determinant also for longevity. Four polymorphisms (−2578C/A, −1190G/A, −1154G/A and −634G/C) within the VEGF gene promoter region in 490 unrelated Italian healthy subjects have been analysed. Significant changes of allele, genotype (−2578/AA versus −2578/CC: OR = 2.08, p = 0.007; −1190/AA versus −1190/GG: OR = 2.01, p = 0.011) and haplotype (AAGG: 10.4% versus 14.9%, p = 0.03) frequency distributions were observed between young/elderly (25–84 years old) and long-lived (85–99 years old) subjects. These results suggest that VEGF gene variability can be inserted among the genetic factors influencing the lifespan.

Psychosocial and biochemical interactions in aging: Preliminary results from an Italian old sample of “Zincage” project

The study of the interactions among biological factors and psychosocial conditions is a very innovative field, because data are lacking in the scientific literature. Among biological aspects, zinc is an essential element in the elderly, especially in relation to one of the proteins, such as albumin, involved in zinc transport into the cells. In this study, the aim is the assessment of the interrelationship between albumin value (used as an index of the body zinc status) and some psychosocial dimensions in elderly Italian sample recruited for ZINCAGE project, supported by the European Commission in the “Sixth Framework Programme”. Some tests and questionnaires were administered to older people included in the trial: the “life-style questionnaire”; the mini mental state examination (MMSE); the geriatric depression scale (GDS-15 items). On the basis of the Senieur Protocol for gerontological studies, a sample of 291 Italian healthy old subjects has been recruited in Central Italy and divided into 3 age groups: (a) 125 subjects aged from 65 to 74 years, (b) 89 subjects aged from 75 to 84 years, (c) 77 subjects aged ≥85 years (classified like successful old people). No cognitive impairment assessed by MMSE was observed in 67.5% of the sample; 64.0% had GDS score less than 5, indicating no depression, whereas the prevalence of biological albumin deficiency (<3.5 g/dl) found in Italian old people was 21.0%. Sixty one percent of subjects with albumin deficiency displayed higher values of GDS (≥5). These preliminary results showed an interrelationship among serum albumin value and psychosocial aspects in Italian old population, suggesting that low albumin values may be involved in impaired psychological dimensions.

CYP1A2 F21L and F186L Polymorphisms in an Italian Population Sample

P450 cytochromes (CYPs) enzymes play a major role in variability of drug response and cancer susceptibility. In particular, up to 60-fold interindividual variation has been detected in the activity of CYP1A2, which is involved in the metabolism of caffeine, several drugs and various toxic and carcinogenic compounds. Aim of this study is to assess the frequency of CYP1A2 F21L and F186L polymorphisms (formerly CYP1A2(*)2 and (*)11 alleles), up to now found in Asiatic populations only. These variants were absent in 500 Italian healthy subjects. Therefore it can be suggested that the variation of CYP1A2-dependent metabolism in the Caucasian population is not related to these two CYP1A2 polymorphisms. Thus, this study supports the view that ethnicity is a relevant factor to be carefully considered in pharmacogenetic studies.

Evidence of a Genetic Basis for the Different Geographic Occurrences of Liver/Kidney Microsomal Antibody Type 1 in Hepatitis C

Antibodies to liver/kidney microsome type 1 occur in Italian patients with hepatitis C, but rarely develop in North American patients. Our goals were to compare the frequencies of the HLA markers associated with autoimmune expression in Italian and North American patients with chronic hepatitis C and to determine genetic bases for regional differences in antibody production. HLA B8, DR3, DR4, DR7, DR11, DR13, DQ2, and the B8-DR3-DQ2 haplotype were determined by microlymphocytotoxicity and polymerase chain reaction in 105 Italian patients (50 with microsomal antibodies), 100 North American patients (none with microsomal antibodies), and Italian and North American healthy control subjects. Italian patients with microsomal antibodies differed from North American patients without these antibodies by having a higher frequency of HLA DR7 (54% vs. 27%, P=0.002). HLA DR7 occurred more frequently in seropositive Italian patients than in seronegative counterparts (54% vs. 11% P < 0.0001), Italian healthy control subjects (54% vs. 29%, P=0.0009), and North American healthy control subjects (54% vs. 19%, P < 0.0001). The frequency of HLA DR7 was similar in North American patients and controls (27% vs. 19%, P=0.2), but it was lower than in Italian controls (19% vs. 29%, P=0.059). Seropositive Italian patients had a lower frequency of HLA DR11 than seronegative Italian patients and Italian controls (18% vs. 34%, P=0.07, and 18% vs. 35%, P=0.02, respectively). In contrast to seropositive Italian patients, North American patients had HLA DR4 (30% vs. 12%, P=0.02), HLA DR13 (29% vs. 10%, P=0.01), and the B8-DR3-DQ2 haplotype (23% vs. 6%, P=0.01) more often. Similarly, HLA DR4 and the B8-DR3-DQ2 phenotype were more frequent in North American patients than in Italian controls (30% vs. 16%, P=0.005, and 23% vs. 7%, P=0.00002, respectively). HLA DR7 is associated with the development of microsomal antibodies in Italian patients with chronic hepatitis C. The lower frequency of HLA DR7 in North America could contribute to the rarity of these antibodies in this region. HLA DR11 may be protective against the development of microsomal antibodies in Italian patients, whereas HLA DR4, HLA DR13, and the B8-DR3-DQ2 haplotype may be protective in North American patients.

Normal values of 24-h ambulatory intraluminal impedance combined with pH-metry in subjects eating a Mediterranean diet

Background and aims Multichannel intraluminal impedance combined with pH-metry is a novel technique for studying gastro-oesophageal reflux. As refluxes are particularly frequent after meals, we carried out this study in order to assess the impact of a Mediterranean diet on normal values of impedancemetry. Methods Twenty-five Italian healthy subjects (13 men, median age 29 years, range 22–67 years) without reflux symptoms were recruited for this study. They underwent oesophageal 24-h impedance + pH-metry. A Mediterranean diet was given to all subjects on the day of examination and its total energy intake was 9668.5 kJ (2300 kcal). Results A total of 1518 refluxes were recorded during 24 h with more upright than recumbent episodes (median 15 versus 0; p < 0.01). The median total acid exposure time was 0.5% (range 0–4.2%). Acid and weakly acidic refluxes were equally reported (49% versus 51%). Weakly acidic episodes were more frequent than acid ones during 1-h postprandial periods (68% versus 32%; p < 0.0001). Liquid-only and mixed refluxes reached the proximal oesophagus (15 cm above lower oesophageal sphincter) in 42.6% of cases. Median acid clearing time was longer than median bolus clearing time (28 s versus 12 s; p < 0.01). Conclusions This study provides normal values of pH-impedancemetry in Italian people eating a Mediterranean diet and are suitable for comparative pathophysiological investigations on reflux patients who have dietary habits similar to those of our country.