Tamás Ferenci

Modeling and optimal control strategies of diseases with high public health impact

This paper summarizes the results of research tasks in the field of physiological modeling and control of diseases with high public health impact carried out by the Biomedical Engineering Laboratory of the Budapest University of Technology and Economics. The developed and presented optimal algorithms and strategies focus on three diseases with high public health impact diabetes (the question of artificial pancreas), obesity (predicting obesity-related risks) and cancer (antiangiogenic chemotherapy). The studies are done together with different Hungarian hospitals, from where measurement data were obtained.

Trends in Major Lower Limb Amputation Related to Peripheral Arterial Disease in Hungary: A Nationwide Study (2004-2012)

OBJECTIVES To assess the trends of peripheral arterial disease associated major lower limb amputation in Hungary over a 9 year period (2004-2012) in the whole Hungarian population. METHODS This was a retrospective cohort study employing administrative health care data. Major amputations were identified in the entire Hungarian population during a 9 year period (2004-2012) using the health care administrative data. Direct standardization was used to eliminate the potential bias induced by the different age and sex structure of the compared populations. For external direct standardization, the ESP 2013 was chosen as reference. RESULTS 76,798 lower limb amputations were performed. The number of major amputations was 38,200; these procedures affected 32,084 patients. According to case detection, 50.4% of the amputees were diabetic. The overall primary amputation rate was 71.5%. The annual crude and age adjusted major amputation rates exhibited no significant long-term pattern over the observation period. The major lower limb amputation incidence for the overall period was 42.3/10(5) in the total population and 317.9/10(5) in diabetic population. CONCLUSION According to this whole population based study from Hungary, the incidence of lower limb major amputation is high with no change over the past 9 years. An explanation for this remains to be determined, as the traditional risk factors in Hungary do not account for it. The characteristics of major amputation (the rate of primary amputation, the ratio of below to above knee amputation and the age of the affected population) underline the importance of screening, early detection, improved vascular care and an optimal revascularization policy. Standardization and validation of amputation detection methods and reporting is essential.

Daily Evolution of Insulin Sensitivity Variability with Respect to Diagnosis in the Critically Ill

Introduction This study examines the likelihood and evolution of overall and hypoglycemia-inducing variability of insulin sensitivity in ICU patients based on diagnosis and day of stay. Materials and Methods An analysis of model-based insulin sensitivity for patients in a medical ICU (Christchurch, New Zealand). Two metrics are defined to measure the variability of a patients insulin sensitivity relative to predictions of a stochastic model created from the same data for all patients over all days of stay. The first selectively captures large increases related to the risk of hypoglycemia. The second captures overall variability. Distributions of per-patient variability scores were evaluated over different ICU days of stay and for different diagnosis groups based on APACHE III: operative and non-operative cardiac, gastric, all other. Linear and generalized linear mixed effects models assess the statistical significance of differences between groups and over days. Results Variability defined by the two metrics was not substantially different. Variability was highest on day 1, and decreased over time () in every diagnosis group. There were significant differences between some diagnosis groups: non-operative gastric patients were the least variable, while cardiac (operative and non-operative) patients exhibited the highest variability. Conclusions This study characterizes the variability and evolution of insulin sensitivity in critically ill patients, and may help inform the clinical management of metabolic dysfunction in critical care.

Hepatic steatosis in individuals living with HIV measured by controlled attenuation parameter: a cross-sectional study.

Objectives Available data on the prevalence of hepatic steatosis in an unselected HIV-infected population are limited. The aim of this study was to determine the prevalence of hepatic steatosis and assess the associated factors in HIV-infected individuals. Patients and methods One hundred and thirty-six HIV-infected individuals were enrolled in this cross-sectional study. Patients underwent transient elastography and controlled attenuation parameter (CAP) measurements. We analyzed the associations between the CAP value and demographic, metabolic, and immunologic parameters. For the first time, in HIV-infected individuals, we used a continuous scale of CAP values to identify significant covariates of hepatic fat accumulation. As a result and compared with other methods, one of the main advantages of CAP was that the quantitative measurement of liver steatosis could be used for analysis. Results Using univariate analysis, CAP was significantly correlated with the following continuous variables: CD4 percentage (P=0.035), CD8 percentage (P=0.016), age (P<0.001), CD4/8 ratio (P=0.002), BMI (P<0.001), serum triglyceride (P<0.001), and serum cholesterol (P=0.004) levels, the length of known HIV positivity (P<0.001), and liver stiffness (P=0.041). With respect to categorical variables, a significant association was found for the presence of diabetes (P=0.006), hypertension (P<0.001), facial lipodystrophy (P=0.031), and the use of lopinavir (P=0.042). In multivariate analysis using linear regression, BMI (P<0.001), presence of diabetes (P=0.026), and hypertension (P=0.040) were identified as independent significant correlates. Darunavir therapy was associated negatively with the CAP value (P=0.032). Conclusion Our findings reflect the importance of metabolic factors in hepatic steatosis. The strongest independent covariate was BMI.

Infliximab biosimilar CT-P13 therapy is effective and safe in maintaining remission in Crohn’s disease and ulcerative colitis – experiences from a single center

ABSTRACT Background: CT-P13, the first biosimilar monoclonal antibody to infliximab (IFX), has been confirmed to be efficacious in inducing remission in inflammatory bowel diseases (IBD). The aim of this study was to evaluate the long-term efficacy and safety of CT-P13 therapy in Crohn’s disease (CD) and ulcerative colitis (UC), and to identify predictors of sustained clinical response during a 54-week CT-P13 treatment period. Patients and methods: Patients with CD and UC, who were administered CT-P13, were prospectively enrolled. Clinical response was assessed at week 14 and week 54. Predictive factors for disease outcome at week 54 were evaluated. Results: 57 CD and 57 UC patients were included; 55 CD and 49 UC patients completed the induction therapy and 50 CD and 46 UC patients completed the 54-week treatment period. Clinical remission was achieved in 65.5% of CD and 75.5% of UC patients at week 14. Rate of continuous clinical response was 51% in both CD and UC at week 54. None of the examined parameters were predictive to the clinical outcome neither in CD, nor in UC. Conclusion: This study confirmed the long-term efficacy and safety of CT-P13 therapy in IBD. Response rates at week 54 were similar in CD and UC.

The issue of plasma asymmetric dimethylarginine reference range – A systematic review and meta-analysis

Background Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide synthase, marker and mediator of endothelial dysfunction. Several studies have demonstrated its value in cardiovascular risk stratification and all-cause mortality prediction. The aim was to determine the reference range of plasma ADMA in healthy adults. Methods and results Taking into account the most widely used ADMA measurement methods, only studies using either high performance liquid chromatography (HPLC) -with fluorescence or mass spectrometric detection-, or enzyme-linked immunosorbent assay (ELISA) to quantify plasma ADMA concentrations were enrolled. 66 studies were included in the quantitative analysis (24 using ELISA and 42 using HPLC) reporting a total number of 5528 non-diabetic, non-hypertensive, non-obese adults without any medication (3178 men and 2350 women, 41.6 ± 16.9 years old). The reference range of ADMA (in μmol/l with 95% confidence interval in parenthesis) was 0.34 (0.29–0.38)– 1.10 (0.85–1.35) with a mean of 0.71 (0.57–0.85) (n = 4093) measured by HPLC and 0.25 (0.18–0.31)– 0.92 (0.76–1.09) with a mean of 0.57 (0.48–0.66) (n = 1435) by ELISA. Conclusions Numerous publications suggested that asymmetric dimethylarginine is not only an outstanding tool of disease outcome prediction but also a new potential therapeutic target substance; the reference range provided by this meta-analysis can become of great importance and aid to further investigations. However, developing a standard measurement method would be beneficial to facilitate the clinical usage of ADMA.

Performance of a new HPV and biomarker assay in the management of hrHPV positive women: Subanalysis of the ongoing multicenter TRACE clinical trial (n > 6,000) to evaluate POU4F3 methylation as a potential biomarker of cervical precancer and cancer

The ongoing Triage and Risk Assessment of Cervical Precancer by Epigenetic Biomarker (TRACE) prospective, multicenter study aimed to provide a clinical evaluation of the CONFIDENCE™ assay, which comprises a human papillomavirus (HPV) DNA and a human epigenetic biomarker test. Between 2013 and 2015 over 6,000 women aged 18 or older were recruited in Hungary. Liquid‐based cytology (LBC), high‐risk HPV (hrHPV) DNA detection and single target host gene methylation test of the promoter sequence of the POU4F3 gene by quantitative methylation‐specific polymerase chain reaction (PCR) were performed from the same liquid‐based cytology sample. The current analysis is focused on the baseline cross‐sectional clinical results of 5,384 LBC samples collected from subjects aged 25 years or older. The performance of the CONFIDENCE HPV™ test was found to be comparable to the cobas® HPV test with good agreement. When applying the CONFIDENCE Marker™ test alone in hrHPV positives, it showed significantly higher sensitivity with matching specificity compared to LBC‐based triage. For CIN3+ histological endpoint in the age group of 25–65 and 30–65, the methylation test of POU4F3 achieved relative sensitivities of 1.74 (95% CI: 1.25–2.33) and 1.64 (95% CI: 1.08–2.27), respectively, after verification bias adjustment. On the basis of our findings, POU4F3 methylation as a triage test of hrHPV positives appears to be a noteworthy method. We can reasonably assume that its quantitative nature offers the potential for a more objective and discriminative risk assessment tool in the prevention and diagnostics of high‐grade cervical intraepithelial neoplasia (CIN) lesions and cervical cancer.

Performance of a New HPV and Biomarker Assay in Management of hrHPV Positive Women

The ongoing Triage and Risk Assessment of Cervical Precancer by Epigenetic Biomarker (TRACE) prospective, multicenter study aimed to provide a clinical evaluation of the CONFIDENCE™ assay, which comprises a human papillomavirus (HPV) DNA and a human epigenetic biomarker test. Between 2013 and 2015 over 6,000 women aged 18 or older were recruited in Hungary. Liquid‐based cytology (LBC), high‐risk HPV (hrHPV) DNA detection and single target host gene methylation test of the promoter sequence of the POU4F3 gene by quantitative methylation‐specific polymerase chain reaction (PCR) were performed from the same liquid‐based cytology sample. The current analysis is focused on the baseline cross‐sectional clinical results of 5,384 LBC samples collected from subjects aged 25 years or older. The performance of the CONFIDENCE HPV™ test was found to be comparable to the cobas® HPV test with good agreement. When applying the CONFIDENCE Marker™ test alone in hrHPV positives, it showed significantly higher sensitivity with matching specificity compared to LBC‐based triage. For CIN3+ histological endpoint in the age group of 25–65 and 30–65, the methylation test of POU4F3 achieved relative sensitivities of 1.74 (95% CI: 1.25–2.33) and 1.64 (95% CI: 1.08–2.27), respectively, after verification bias adjustment. On the basis of our findings, POU4F3 methylation as a triage test of hrHPV positives appears to be a noteworthy method. We can reasonably assume that its quantitative nature offers the potential for a more objective and discriminative risk assessment tool in the prevention and diagnostics of high‐grade cervical intraepithelial neoplasia (CIN) lesions and cervical cancer.

Quantitative impact of direct, personal feedback on hand hygiene technique

This study investigated the effectiveness of targeting hand hygiene technique using a new training device that provides objective, personal and quantitative feedback. One hundred and thirty-six healthcare workers in three Hungarian hospitals participated in a repetitive hand hygiene technique assessment study. Ultraviolet (UV)-labelled hand rub was used at each event, and digital images of the hands were subsequently taken under UV light. Immediate objective visual feedback was given to participants, showing missed areas on their hands. The rate of inadequate hand rubbing reduced from 50% to 15% (P < 0.001). However, maintenance of this reduced rate is likely to require continuous use of the electronic equipment.

Model-based optimal therapy for high-impact diseases

The current paper represents a continuation of the conference papers presented at the INES 2011 and 2012 conferences. A brief summary of the newest results in the field of physiological modeling and control are presented focusing on high public health impact diseases: diabetes, tumor and obesity. In the case of diabetes control, preliminary model-free results of the developed robust control framework is presented, while in the case of tumor control we have started to create a new tumor growth model based on clinical experiments. In the case of biostatistical investigation of obesity, new aspects of relationship between overweight/obesity and laboratory results was examined.