Multiplex STR amplification sensitivity in a silicon microchip

The demand for solutions to perform forensic DNA profiling outside of centralized laboratories is increasing. We here demonstrate highly sensitive STR amplification using a silicon micro-PCR (mu PCR) chip. Exploiting industry-standard semiconductor manufacturing processes, a device was fabricated that features a small form factor thanks to an integrated heating element covering three parallel micro-reactors with a reaction volume of 0.5 mu l each. Diluted reference DNA samples (1 ng-31 pg) were amplified on the mu PCR chip using the forensically validated AmpFISTR Identifier Plus kit, followed by conventional capillary electrophoresis. Complete STR profiles were generated with input DNA quantities down to 62 pg. Occasional allelic dropouts were observed from 31 pg downward. On-chip STR profiles were compared with those of identical samples amplified using a conventional thermal cycler for direct comparison of amplification sensitivity in a forensic setting. The observed sensitivity was in line with kit specifications for both mu PCR and conventional PCR. Finally, a rapid amplification protocol was developed. Complete STR profiles could be generated in less than 17 minutes from as little as 125 pg template DNA. Together, our results are an important step towards the development of commercial, mass-produced, relatively cheap, handheld devices for on-site testing in forensic DNA analysis

Liver transplantation for alcoholic liver disease: a retrospective analysis of recidivism, survival and risk factors predisposing to alcohol relapse

Background and study aims : Alcoholic liver disease (ALD) is the second most common indication for liver transplantation. The aim of this study was to evaluate the alcohol relapse rate and long-term survival after liver transplantation for ALD and to identify risk factors predisposing to alcohol relapse. Patients and methods : Between 2000 and 2007, 108 patients transplanted for ALD in the Ghent University Hospital were included in this retrospective analysis. Relapse was defined as any drinking after transplantation, problem drinking as more than 2 units/day for women and 3 units/day for men. A wide range of variables was obtained from a questionnaire and medical records. Results : The mean follow-up was 55 months. Relapse was observed in 29%, 16% in problem drinking. The one-and five-year survival was 87% and 74% respectively. No significant difference in survival was found between non-relapsers, occasional drinkers and problem drinkers. The following risk factors were found to be significantly associated with relapse into problem drinking in an univariate analysis : a shorter pre-transplant abstinence period, the presence of a first degree relative with alcohol abuse and a higher number of prior attempts to quit. In multivariable analysis, the presence of a first degree relative with alcohol abuse was found associated with relapse into problem drinking. Conclusions : The presence of a first degree relative with alcohol abuse is a valuable pre-transplant variable evaluating an ALD patient's eligibility for liver transplantation. Other variables are also helpful to outline the broader context of the drinking behavior of the patient

Clinical burden of hepatitis E virus infection in a tertiary care center in Flanders, Belgium

Background: Hepatitis E virus (HEV) infection is increasingly recognized as a cause of hepatitis in developed countries. A high HEV IgG seroprevalence in humans and pigs is reported as well as sporadic clinical cases of autochtonous HEV but there are currently no data available on the clinical burden of HEV in Belgium. Objectives: The objective of the current study was to evaluate the actual clinical burden of HEV infections in our tertiary care center in Flanders, Belgium. Study design: In the setting of Ghent University Hospital, patients were assessed for the presence of HEV IgG and IgM as well as HEV RNA if no other cause was found for one of the following clinical presentations: a) elevation of liver enzymes in post-liver transplant; b) suspicion of acute or toxic hepatitis; c) unexplainable elevation of liver enzymes; d) cirrhosis with acute-on-chronic exacerbation. Results: In a period of 39 months (January 2011-April 2014) 71 patients were enrolled. HEV IgG was found positive in 13 (18,3%) patients; HEV IgM in 6 patients (8,5%) and HEV RNA in 4 (5,6%) patients. All HEV IgM/ RNA positive patients were male, aged 41-63, and classified in the clinical groups a), b) or d). HEV IgG seroprevalence was slightly higher but not significantly different from the seroprevalence in the general population in this region in Belgium previously reported to be 14% (p-value 0.41) by our group. Conclusions: HEV should be considered as a cause of liver pathology especially in middle-aged men with elevation of liver enzymes

Development and validation of a prognostic score for long-term transplant-free survival in autoimmune hepatitis type 1

Background No prognostic score is currently available for long-term survival in autoimmune hepatitis (AIH) patients. Objective The aim of this study was to develop and validate such a prognostic score for AIH patients at diagnosis. Methods The prognostic score was developed using uni- & multivariate Cox regression in a 4-center Dutch cohort and validated in an independent 6-center Belgian cohort. Results In the derivation cohort of 396 patients 19 liver transplantations (LTs) and 51 deaths occurred (median follow-up 118 months; interquartile range 60-202 months). In multivariate analysis age (hazard ratio [HR] 1.045; p < 0.001), non-caucasian ethnicity (HR 1.897; p = 0.045), cirrhosis (HR 3.266; p < 0.001) and alanine aminotransferase level (HR 0.725; p = 0.003) were significant independent predictors for mortality or LT (C-statistic 0.827; 95% CI 0.790-0.864). In the validation cohort of 408 patients death or LT occurred in 78 patients during a median follow-up of 74 months (interquartile range: 25-142 months). Predicted 5-year event rate did not differ from observed event rate (high risk group 21.5% vs. 15.7% (95% CI: 6.3%-24.2%); moderate risk group 5.8% versus 4.3% (95% CI: 0.0%-9.1%); low risk group 1.9% versus 5.4% (95% CI: 0.0%-11.4%); C-statistic 0.744 [95% CI 0.644-0.844]). Conclusions A Dutch-Belgian prognostic score for long-term transplant-free survival in AIH patients at diagnosis was developed and validated

Magnetic particle detection for quantification of biomolecules

status: publishe

Magnetic particle detection : for quantification of biomolecules

status: publishe