Assessment of body composition: Intrinsic methodological limitations and statistical pitfalls.

Evaluation of body composition (BC) is crucial for an adequate assessment of nutritional status and its alterations, to ensure the optimal tailoring of nutritional therapies during several pathologic conditions. The need for feasible and reliable methods for BC measurement, which could be applied either in healthcare across the lifespan as well as in clinical research and epidemiologic studies, has led to the development of various techniques. Unfortunately, they have not always produced equivalent results due to the fact that they are based on completely different principles or suffer intrinsic biases related to specific conditions. Furthermore, different population and clinical settings (ethnicity, age, type of disease) may interfere, thereby leading to dissimilar results. Finally, the need to compare the data obtained by new techniques to a reference standard has produced a further bias, due to a systematic misinterpretation of the statistical methods in the attempt to correlate the various techniques. In this context, the most used statistical methods for the comparison between different techniques have been Pearson's correlation test, the more recent intraclass correlation coefficient, Lin's concordance correlation coefficient method, and the Bland-Altman analysis. The aim of this review was to offer a summary of the methods that are mostly used in clinical practice to measure BC with the intent to give appropriate suggestions when statistical methods are used to interpret data, and underline pitfalls and limitations.

Forecasting Hepatitis C liver disease burden on real-life data. Does the hidden iceberg matter to reach the elimination goals?

BACKGROUND & AIMS: Advances in direct-acting antiviral treatment of HCV have reinvigorated public health initiatives aimed at identifying affected individuals. We evaluated the possible impact of only diagnosed and linked-to-care individuals on overall HCV burden estimates and identified a possible strategy to achieve the WHO targets by 2030. METHODS: Using a modelling approach grounded in Italian real-life data of diagnosed and treated patients, different linkage-to-care scenarios were built to evaluate potential strategies in achieving the HCV elimination goals. RESULTS: Under the 40% linked-to-care scenario, viraemic burden would decline (60%); however, eligible patients to treat will be depleted by 2025. Increased case finding through a targeted screening strategy in 1948-1978 birth cohorts could supplement the pool of diagnosed patients by finding 75% of F0-F3 cases. Under the 60% linked-to-care scenario, viraemic infections would decline by 70% by 2030 but the patients eligible for treatment will run out by 2028. If treatment is to be maintained, a screening strategy focusing on 1958-1978 birth cohorts could capture 55% of F0-F3 individuals. Under the 80% linked-to-care scenario, screening limited in 1968-1978 birth cohorts could sustain treatment at levels required to achieve the HCV elimination goals. CONCLUSION: In Italy, which is an HCV endemic country, the eligible pool of patients to treat will run out between 2025 and 2028. To maintain the treatment rate and achieve the HCV elimination goals, increased case finding in targeted, high prevalence groups is required.

May the assessment of baseline mucosal molecular pattern predict the development of gluten related disorders among microscopic enteritis?

AIM: To evaluate mucosal baseline mRNA expression of tissue transglutaminase 2 (tTG2), interferon gamma (IFNγ), toll-like receptor 2 (TLR2) and Myeloid Differentiation factor 88 (MyD88) in patients with microscopic enteritis (ME). METHODS: We retrospectively enrolled 89 patients with ME of different etiology, which was defined within a 2-year mean period of follow-up. Baseline histological examination was performed on Hematoxylin-Eosin stained sections and CD3 lymphocyte immunohistochemistry was used for intraepithelial lymphocyte count (IELs). ME was defined according to the criteria of Bucharest Consensus Conference. For each patient, formalin embedded biopsy samples of the duodenum referred to the period of ME diagnosis were retrieved. Real-time polymerase chain reaction (RT-PCR) was used to detect the amount of mRNA coding for tTG2, IFNγ, TLR2 and MyD88, and the quantity was expressed as fold change compared to controls. Control group was represented by duodenal normal specimens from 15 healthy subjects undergoing endoscopy for functional symptoms. Comparisons among continuous variables were performed by One way analysis of variance (ANOVA) and Bonferroni's test. The χ(2) test was used for categorical variables. Pearson's test was used to evaluate correlations. Receiver operating curves were drawn for all four markers to estimate sensitivity and specificity in discriminating the development of CD and GS. RESULTS: After a period of follow up of 21.7 ± 11.7 mo, the following diagnoses were achieved: gluten related disorders in 48 subjects (31 CD; 17 GS) and non-gluten related ones in 41 (29 Irritable Bowel Syndrome - IBS; 12 Others). CD patients had the highest tTG2 levels (8.3 ± 4.5). The ANOVA plus Bonferroni analysis showed that CD > Other ME > GS = IBS > negative controls. A cut off value of 2.258 was able to discriminate between CD and GS with a sensitivity of 52.94% and a specificity of 87.1%. Additionally, CD patients had the highest IFNγ levels (8.5 ± 4.1). ANOVA plus Bonferroni demonstrated CD > Other ME > GS = IBS > negative controls. A cut off of 1.853 was able to differentiate CD and GS with a sensitivity of 47.06% and a specificity of 96.77%. Patients with non gluten-related causes of ME exhibited the highest TLR2 levels (6.1 ± 1.9) as follows: Other ME > CD = GS = IBS > negative controls. TLR2 was unable to discriminate CD from GS. Patients with CD overexpressed MyD88 levels similarly to non gluten-related causes of DL (7.8 ± 4.9 and 6.7 ± 2.9), thus CD = Other ME > GS = IBS > negative controls. A cut off of 3.722 was able to differentiate CD from GS with a sensitivity of 52.94% and a specificity of 74.19%. IELs count (15-25 and more than 25/100 enterocytes) strongly correlated with mRNA levels of all tested molecules (P < 0.0001). CONCLUSION: Our results confirm that a single marker is unable to predict a discrimination among ME underlying conditions as well as between CD and GS. Mucosal high levels of tTG and IFNγ mRNA may predict the development of CD more than GS with high specificity, despite an expected low sensitivity. TLR2 does not discriminate the development of CD from GS. MyD88 levels indicate that intestinal permeability is more increased when a severe intestinal damage underlies ME in both gluten related and unrelated conditions. Therefore, the results of the present paper do not seem to show a clear translational value.

Gastrointestinal bleeding from vascular malformations: Is octreotide effective to rescue difficult-to-treat patients?

Gastrointestinal vascular malformations are responsible for 2-8% of all cases of bleeding and 30-40% of all obscure hemorrhages, being the most frequent cause of occult bleeding in older people. The aim of this review was to provide an up-to-date report about the use of octreotide in bleeding from both hereditary and acquired vascular malformations of the gastrointestinal tract. A systematic literature search was performed, using the keywords "gastrointestinal vascular malformation", "octreotide", "angiodysplasia", "portal hypertensive gastropathy", "gastric antral vascular ectasia", and "hereditary vascular malformations". The first line therapy of acute/chronic bleeding from digestive vascular malformations is endoscopy, followed by angiographic embolization and surgical resection when this is unsuccessful. In the setting of difficult-to-treat patients, octreotide has been proposed as an alternative therapeutic strategy. Studies reported in the literature show a high efficacy and safety of octreotide, but described only a small number of enrolled patients, heterogeneous therapeutic schedules and short-term follow-up, with the exception of acute bleeding from esophageal varices. As a consequence, the use of octreotide is not approved in this setting and it is currently still prescribed as an off-label drug. Studies in larger populations are needed to confirm the promising results observed in the small case series reports, so as to provide physicians with a treatment option for patients without available alternatives. Octreotide could also determine a strong decrease in the management costs of these clinical conditions, and especially, could dramatically reduce hospital admission costs.