Designing a Simple Electrochemical Genosensor for the Detection of Urinary PCA3, a Prostate Cancer Biomarker

This study investigates the feasibility of a simple electrochemical detection of Prostate Cancer Antigen 3 (PCA3) fragments extracted from patients' urine, using a thiolated single-strand DNA probe immobilized on a gold surface without using a redox probe. To enhance the PCA3 recognition process, we conducted a comparative analysis of the hybridization location using two thiolated DNA probes: Probe 1 targets the first 40 bases, while Probe 2 targets the fragment from bases 47 to 86. Hybridization with PCA3 followed, using square wave voltammetry. The limit of detection of the designed genosenors were of the order of (2.2 ng/mL), and (1.6 ng/mL) for Probes 1 and 2, respectively, and the subsequent sensitivities were of the order of (0.09 ± 0.01) µA-1 · µg-1 · mL and (0.10 ± 0.01) µA-1 · µg-1 · mL. Specificity tests were then conducted with the sensor functionalized with Probe 2, as it presents better analytical performances. The electrochemical results indicate that the designed sensor can clearly discriminate a complementary target from a non-complementary one. A further modeling of the calibration curves with the Power Law/Hill model indicates that the dissociation constant increases by one order of magnitude, confirming the ability of the designed sensor to perfectly discriminate complementary targets from non-complementary ones.

A Population Pharmacokinetic Model to Predict the Individual Starting Dose of Tacrolimus for Tunisian Adults after Renal Transplantation

BACKGROUND

Tacrolimus is the most frequently used immunosuppressive drug for preventing renal rejection. However, its use is hampered by its narrow therapeutic index and large intra and interpatient variability in pharmacokinetics. The objective of this study was to externally validate a tacrolimus population pharmacokinetic model developed for the Dutch population and adjust the model for the Tunisian population for use in predicting the starting dose requirement after kidney transplantation.

METHODS

Data on tacrolimus exposure were obtained from kidney transplant recipients (KTRs) during the first 3 months post-transplantation. External validation of the Dutch model and its adjustment for the Tunisian population was performed using nonlinear mixed-effects modeling.

RESULTS

In total, 1901 whole-blood predose tacrolimus concentrations from 196 adult KTRs were analyzed. According to a visual predictive check, the Dutch model underestimated the starting dose for the Tunisian adult population. The effects of age, together with the CYP3A5*3 and CYP3A4*22 genotypes on tacrolimus clearance were significantly different in the Tunisian population than in the Dutch population. Based on a bodyweight-based dosing, only 21.9% of tacrolimus concentrations were within the target range, whereas this was estimated to be 54.0% with the newly developed model-based dosing. After adjustment, the model was successfully validated internally in a Tunisian population.

CONCLUSIONS

A starting-dose population pharmacokinetic model of tacrolimus for Tunisian KTRs was developed based on a previously published Dutch model. Using this starting dose could potentially increase the percentage of patients achieving target tacrolimus concentrations after the initial starting dose.

The pharmacogenetics of tacrolimus in renal transplant patients: association with tremors, new-onset diabetes and other clinical events

Our study is the first study to investigate the effect of SNPs in CYP3A5, CYP3A4, ABCB1 and POR genes on the incidence of tremors, nephrotoxicity, and diabetes mellitus. A total of 223 renal transplant patients receiving tacrolimus and mycophenolate mofetil (MMF) were recruited. Both adults and children patients participated in the study. Genotyping was performed using PROFLEX-PCR followed by RFLP. MPA and tacrolimus plasma concentrations were measured by immunoassay. The AUC0-12h of MMF was estimated by a Bayesian method. We found a statistically significant association between the CYP3A5*3 and CYP3A4*1B genotypes and the tacrolimus exposure. We found a lower occurrence of nephrotoxicity (p = 0.03), tremor (p = 0.01), and new-onset diabetes (p = 0.002) associated with CYP3A5*1 allele. The CYP3A4*1B allele was significantly associated with a lower occurrence of new-onset diabetes (p = 0.026). The CYP3A5*1 allele was significantly associated with an increased risk of acute and chronic rejection (p = 0.03 and p < 0.001, respectively). Our results support the usefulness of tacrolimus pharmacokinetics in pre-kidney transplant assessments.

Association between Human Leukocyte Antigen (HLA) DQB1*06 and HLA DQB1*03 and adverse outcomes in a group of critically ill patients with COVID-19 in Tunisia: a cross-sectional study

Introduction

Human Leukocyte Antigen (HLA) system is a highly polymorphic genetic system associated with the prognosis of several infectious diseases. The aim of this study is to investigate the association of HLA polymorphism with the outcome of coronavirus disease 2019 (COVID-19) in Tunisian critically ill patients.

Methods

this retrospective cross-sectional study included 42 consecutive patients hospitalized in intensive care unit (ICU) for COVID-19 in March 2021. Genotyping of HLA loci was performed by LABType™ sequence-specific oligonucleotide (SSO) typing kits (One lambda Inc, USA). Statistical analyses were performed using Statistical Package for Social Sciences (SPSS®) version 23.0. A p-value <0.05 was considered significant. Multivariable regression analysis was performed for the association between HLA polymorphism with adverse outcomes with adjustment for potential confounders such as age, sex, co-morbidities and blood type.

Results

patients included in our study had a mean age of 64.5 ± 11.5 (34-83) years and were mainly men (64.3%; (n=27)). The most common cardiovascular risk factors were obesity (61.9%; (n=26)) and hypertension (26.2%; (n=11)). Thirty-two patients died (76.2%). Eleven patients (26.2%) required intubation during hospitalization. We found that HLA DQB1*06 allele was significantly associated with protection against mortality aOR: 0.066, 95% CI 0.005-0.821; p = 0.035. HLA DQB1*03 allele was significantly associated with protection against intubation aOR: 0.151, 95% CI 0.023-0.976; p = 0.047.

Conclusion

it was found that there are 2 protective HLA alleles against COVID-19 severity and mortality in critically ill patients. This could allow focusing on people genetically predisposed to develop severe forms of COVID-19.

Effect of Pre-Meal Metformin With or Without an Acute Exercise Bout on Postprandial Lipemic and Glycemic Responses in Metabolic Syndrome Patients: A Randomized, Open Label, Crossover Study

INTRODUCTION

Both exercise and pre-meal metformin could lower postprandial glucose and lipid profiles.

AIMS

To explore whether pre-meal metformin administration is superior to metformin administration with the meal in reducing postprandial lipid and glucose metabolism, and whether its combination with exercise confer superior benefits in metabolic syndrome patients.

MATERIALS AND METHODS

In a randomized crossover design, 15 metabolic syndrome patients were assigned to 6 sequences including 3 experimental conditions: metformin administration with a test meal (met-meal), metformin administration 30 min prior to a test meal (pre-meal-met) with or without an exercise bout designed to expend 700 Kcal at 60% VO₂ peak performed the evening just before pre-meal-met condition. Only 13 participants (3 males, 10 females; age: 46 ± 9.86, HbA1c: 6.23 ± 0.36) were included in the final analysis.

RESULTS

Postprandial triglyceridemia was unaffected by any condition (all P > .05). However, both pre-meal-met (-7.1%, P = .009) and pre-meal-metx (-8.2%, P = .013) significantly reduced total cholesterol AUC with no significant differences between the two latter condition (P = .616). Similarly, LDL-cholesterol levels were significantly lower during both pre-meal-met (-10.1%, P = .013) and pre-meal-metx (-10.7%, P = .021) compared to met-meal with no difference between latter conditions (P = .822). Plasma glucose AUC was significantly reduced by pre-meal-metx compared to both pre-meal-met (-7.5%, P = .045) and met-meal (-8%, P = .03). Insulin AUC was significantly lower during pre-meal-metx compared to met-meal (-36.4%, P = .044).

CONCLUSIONS

Metformin administration 30 minutes prior to meal seems to exert favorable effects on postprandial TC and LDL-Cholesterol levels compared to its administration with meal. Addition of one exercise bout only improved postprandial glycemia and insulinemia.

TRIAL REGISTRY

Pan African clinical trial registry, Identifier PACTR202203690920424.

[Epidemiology of smoking in the male population in Tunisia. HSHS Study 6]

OBJECTIVES

To determine the prevalence of smoking in the male population of Hammam Sousse (Tunisia), to describe its modalities and to analyse its determining factors.

METHODS

This was a "community-based" study, carried out on a random sample of households, including a population of males aged 20 or over. The data were collected, at home, using a specific support consisting of a lifestyle questionnaire, a physical examination, and a biological assessment, oriented towards cardiovascular risk factors. Smoking behaviour covered both forms of cigarettes and Narghile. "Current smokers" included all men declaring that they smoked at the time of the survey, including "regular smokers", who smoked daily at the time of the survey, and "occasional smokers", less than once a day. The group of "non-smokers" at the time of the survey was the sum of "ex-smokers" and those "who had never smoked". The prevalences were calculated after their weighting according to age and the adjusted odds ratios were measured following a multivariate study by logistic regression.

RESULTS

The study population was composed of 481 men with an average age of 49.6±16.35 years and a median of 49 years. Mean body mass index and systolic blood pressure were 26.9 kg/m2 ±4.20 and 151.9 mmHg±24.36, respectively. After adjusting for age, the proportions of current users, former users and subjects who had never used tobacco (all forms combined) were respectively 50.4% (95% CI [49.49-51.3]), 17.4% (95% CI [16.71-18.08]) and 30.9% (95% CI [30.06-31.73]). Daily cigarette consumption was characterized by an average onset at age 20.1±6.91 years, an average duration of 27.0±15.22 years and an average amount of 17.6±9.8 cigarettes smoked per day. After adjusting for age, level of education, and socioeconomic level, smoking behaviour was attributed to a single independent risk factor: the presence of a smoker in the family, with an adjusted OR of 45.17 (p (p<10^-3) for regular cigarette smokers, and 29.66 for regular tobacco users of all forms.

CONCLUSION

Smoking would be a real endemic in Tunisia, threatening the cardiovascular health of the country. The national health system is called upon to strengthen its action plan for the prevention and control of smoking, in all living environments: family, school, work, health centre, etc.

Epidemiology of dyslipidemia in Tunisia, HSHS 3 study (Hammam Sousse Sahloul Heart Study)

INTRODUCTION

Dyslipidemia is a major cause of morbidity and mortality worldwide because it increases the risk of cardiovascular diseases.

AIM

To determine the prevalence of dyslipidemia and its components in the general population of Hammam Sousse (Tunisia) and to identify its risk factors.

METHODS

This was an analysis of the HSHS database (Hammam Sousse Sahloul Heart Study), a «community-based» cross-sectional study on cardiovascular risk factors including dyslipidemia, with a random sample in two-stages, proportional-probability clusters. All subjects above 20 years underwent a lifestyle interview, clinical examination with anthropometric measurements, and blood sampling. Dyslipidemia was defined by: total cholesterol ≥5.2 mmol/l, hyper LDL (Low Density Lipoprotein) cholesterolemia ≥4.1 mmol/l, hypo HDL (High Density Lipoprotein) cholesterolemia <1.03 mmol/l for men and <1.29 mmol/l for women and hyper-triglyceridaemia: ≥2.26 mmol/l. Multivariate logistic regression analysis was conducted to determine factors independently associated with dyslipidemia.

RESULTS

The study population was composed of 481 males (M) and 960 females (F), with a sex ratio of 0.5. Mean cholesterol was higher in women (5 mmol/l±1.01) than in men (4.8 mmol/l±0.92). Only 24.9% of men and 29.1% of women had normal HDL cholesterol levels. Women had higher levels of hypercholesterolemia and LDL cholesterolemia than men (p<10-6). Multivariate analysis showed that dyslipidemia was independently and statistically significantly associated with age ≥40 years (p<10-3), physical inactivity (p<10-3) and obesity (p=0.025).

CONCLUSION

As a result of the epidemiological situation of dyslipidemia, the promotion of an active lifestyle seems essential. In addition, nutritional education improves the lipid profile by promoting weight loss and balancing lipid consumption.

DPYD and TYMS polymorphisms as predictors of 5 fluorouracil toxicity in colorectal cancer patients

Colorectal cancer (CRC) is the third most common cancer and the fourth leading cause of cancer death. 5-Fluorouracil (5-FU) is an essential component of systemic chemotherapy for CRC. Our objective was to determine the genotypic frequency of polymorphisms affecting dihydropyrimidine dehydrogenase (DPYD) and thymidylate synthetase (TYMS) genes and to correlate the genetic profile with the toxicity due to 5-FU, also considering nongenetic factors. This is a prospective study that involved 66 patients. We extracted DNA by salting out methods. We carried out the genotyping of the different polymorphisms by simple PCR for the TYMS 5'UTR and by PCR-RFLP for DPYD: 1905 + 1 G > A, 85 T > C, 496 A > G, 1679 T > G, c.483 + 18G > A and the TYMS: 5'UTR VNTR, 5'UTR G > C and 3'UTR. The study of the association of DPYD and TYMS polymorphisms with the various signs of toxicity under 5-FU revealed that the polymorphisms 496 A > G were significantly associated with hepatotoxicity: OR = 3.85 (p = 0.04). In addition, 85 T > C was significantly associated with mucositis and neurotoxicity: OR = 4.35 (p = 0.03), OR = 3.79 (p = 0.02). For TYMS, the only significant association we observed for 5'UTR with vomiting: OR = 3.34 (p = 0.04). The incidence of adverse reactions related to 5-FU appears to be influenced in patients with CRC by the identified DPYD and TYMS gene polymorphisms in the Tunisian population.

Novel sensitive immunosensor for the selective detection of Engrailed 2 urinary prostate cancer biomarker

Engrailed 2 (EN2) is a homeodomain-containing transcription factor expressed in prostate cancer (PCa) cell lines and is secreted into the urines. It is nowadays considered as a promising non-invasive biomarker for PCa early diagnosis. Herein, we report the design of an electrochemical immunosensor for EN2 detection. The biosensor fabrication involved a covalent immobilization of anti-EN2 antibodies onto a poly para amino benzoic acid (PABA) film electropolymerized on a gold electrode. Square wave voltammetry was investigated for EN2 detection in a phosphate buffer solution in a concentration range of 10^-5 ng/mL to 1 μg/mL. The limit of detection of the designed sensor was equal to 10^-5 ng/mL and the sensitivity was of order of (29 ± 2) μL/ng. The dissociation constant K_d of the "complex" EN2/anti-EN2, estimated from a Hill model, was of order of (0.9 ± 0.2) fM. Experimental results revealed that the immunosensor enabled selective detection of EN2 in a mixture of three proteins which can be found in men' urine: human serum albumin (HSA), prostate-specific antigen (PSA) and immunoglobulin G (IgG). Tests in artificial urine, with an ionic strength of 0.18 M, have been done and results were found comparable to those obtained in PBS (0.16 M). These encouraging results show a potentially promising future for the development of an electrochemical biosensor for robust and accurate urinary biomarkers detection.

Epidemiology of metabolic syndrome in Tunisia. HSHS 5 study

OBJECTIVE

To measure the prevalence of metabolic syndrome and its components in the HSHS cohort (Hammam Sousse, Tunisia), in 2009, and to identify its determining factors.

METHODS

This was a descriptive epidemiological study of the "community based" type having focused on a random sample of people aged 20 and over. The metabolic syndrome was defined according to the criteria of the "International Diabetes Federation" (IDF 2005) and those of the "National Cholesterol Education Program-Adult Treatment Panel III" (NCEP-ATP III, 2001).

RESULTS

The study involved 1441 people including 960 women (66.6%). The age- and sex-adjusted prevalences of increased waist circumference, blood pressure, blood sugar and triglycerides, and decreased HDL-cholesterol were respectively 63.2%, 95%CI[62.5-63.8]; 47.7%, 95%CI[47.4-48.6]; 25.7%, 95%CI[25.1-26.2]; 11.9%, 95%CI[11.4-12.3] and 65,6%, 95%CI[65.0-66.2], according to IDF thresholds and 37.4%, 95%CI[36.3-37.6]; 45.7%, 95%CI[45.4-46.6]; 13.8%, 95%CI[13.4-14.2]; 8.4%, 95%CI[8.0-8.7] and 61.9%, 95%CI[61.2-62.5], according to those of the NCEP-ATP III. The prevalence of metabolic syndrome adjusted for age and sex was 36.5% 95%CI[33.0%-38.9%] according to the IDF definition and 23.0% 95%CI[20.4%-25.6%] according to that of NCEP-ATP III. The multivariate study by logistic regression made it possible to retain three significant independent determining factors of the metabolic syndrome: age ≥40 years, low level of physical activity and family history of diabetes mellitus with respectively adjusted ORs of 3.77 95%CI[2.70-5.27], 1.39 95%CI[1.01-1.89], 1.62 95%CI[1.21-2.15], according to IDF and 5.87 95%CI[3.88 -8.88], 1.47 95%CI[1.07-2.01] and 1.45 95%CI[1.07-1.96], according to NCEP-ATP III .

CONCLUSION

With this high prevalence rate of the metabolic syndrome, the establishment of an action plan would be essential. This plan should be based on the combination of the promotion of physical activity and screening for the components of the metabolic syndrome, particularly in subjects aged 40 or over, with a family history of diabetes mellitus.

Epidemiology of obesity in Tunisia: HSHS4 study (Hammam Sousse Sahloul Heart Study)

INTRODUCTION

The HSHS study is a community-based survey focused on cardiovascular risk factors.

AIM

The objectives of this specific analysis were to determine the prevalence of obesity and overweight in the general population of Hammam Sousse (Tunisia) and to identify their predisposing factors.

METHODS

HSHS was conducted with a random sample of households, composed by the EPI (Expanded Program on Immunization) technique. All people aged 20 and over, met on the day of the survey, at their homes, were included. Obesity, overweight and weight overload were defined with reference to Body Mass Index (BMI): Obesity (BMI≥30 kg/m²), Overweight (25≤BMI (25≤BMI <30 kg/m²), weight overload (BMI≥25 kg/m²). Physical activity was evaluated according to the level of energy equivalents (Metabolic Equivalent Task) or MET, this level was considered low below 600 MET min/week. The calculated prevalences were accompanied by their 95%CI (Confidence Intervals). The multivariate study was conducted by logistic regression, measuring the adjusted Odds Ratio (ORa) Results: The study population was composed of 481 men and 960 women, (sex-ratio=0.50). The age ranged from 20 to 96 years with an average of 49.6±16444 years in men and 46.6±16.2 in women (p <0.05). After adjusting for age and sex, the prevalence rates of overweight, obesity, and weight overload were respectively 36.18%, 95%CI [35.38%-36.62%], 28.11%; 95%CI [27.42%-28.58%] and 64.28%; 95%CI [63.38%-64.62%]. Obesity was determined, in addition to female sex, age 40 or over and low level of education, by low level of physical activity (ORa=1.56; 95%CI [1.21-2.03], p<10^-2).

CONCLUSION

In adults, the prevalence of obesity and overweight were high and determined by insufficient physical activity. The results of this study, which can be extrapolated to other Tunisian cities, should motivate the general population to establish a heart health promotion plan, in partnership with civil society.

The pharmacogenetics of mycophenolate mofetil in Tunisian renal transplant patients

Aim: The effects of variants in IMPDH, UGT1A9, UGT1A8, UGT2B7 and SLCO1B1 genes on the efficacy and safety of mycophenolate mofetil (MMF) in the Tunisian population were investigated. Materials & methods: A total of 245 kidney transplant patients being treated with MMF were recruited and cotreated with cyclosporine or tacrolimus. Genotyping was performed using the polymerase chain reaction-restriction fragment length polymorphism method. MMF, cyclosporine and tacrolimus trough levels were measured by immunoassay. The AUC (AUC_0-12hMPA) was estimated by a Bayesian method. Results: In the tacrolimus-treated group, anemia and diarrhea were associated with the UGT1A9-98C and UGT1A9-275T alleles, respectively (p < 0.05). In the cyclosporine-treated group, leukopenia was associated with the SLCO1B1-521T allele (p < 0.05). Both groups had an increased risk of rejection (p < 0.05) associated with the variant alleles of IMPDH2-3757T>C, UGT1A9-2152C>T and UGT1A9-275C>A and the common allele of SLCO1B1-388A>G. However, no significant association was found between the studied genotypes and AUC_0-12hMPA or cotreatment levels. Conclusion: The results constitute preliminary evidence for the inclusion of the pharmacogenetics of MMF in kidney pretransplantation evaluations.

Epidemiology of diabetes mellitus in Tunisia. HSHS 2 study (Hammam Sousse Sahloul Heart Study)

BACKGROUND

National epidemiological studies on diabetes mellitus are rare, ancient and often carried out schools or clinics settings.

OBJECTIVES

To determine the prevalence of diabetes mellitus and identify its risk factors in the adult population of the city of Hammam Sousse (Tunisia) during the year 2009.

METHODS

This study is a part of analysis of the HSHS database (Hammam Sousse Sahloul Heart Study), a «community-based» cross-sectional study on cardiovascular risk factors including diabetes mellitus, with a two-stage proportional probability cluster random sample. All subjects aged 20 years and more underwent a lifestyle interview, clinical examination with anthropometric measurements, and blood sampling. The diagnosis of diabetes mellitus was defined by a fasting blood glucose level ≥7 mmol/l. Overweight was defined by a Body Mass Index (BMI) ≥ 25 kg/m². A multivariate logistic regression analysis was conducted to determine independent risk factors associated with diabetes mellitus.

RESULTS

The population was composed of 481 males (M) and 960 females (F), a sex ratio of 0.5 with mean ages respectively of 49.6±16.35 years and 46.6±16.18 years. The prevalence of diabetes mellitus adjusted by age and sex was 12.1% (95%CI[11.7-12.5]); M: 12.7% (95%CI[12.1-13.3]), F: 11.5% (95%CI[10.9-12.1]). The prevalence rate of patients newly detected with diabetes mellitus was 1.9% (95%CI[1.7-2.1]): M: 1.8% (95%CI[1.6-2.0]), F: 2.1% (95%CI[1.8-2.4]). The multivariate study revealed five independent factors significantly associated with diabetes mellitus. In addition to non-modifiable factors (male gender, age ≥40 years old, low schooling level and family history of diabetes), diabetes mellitus was 2 (95%CI[1.3-3.2]) times more prevalent in overweight cases.

CONCLUSION

In deep trouble of this epidemiological situation of diabetes mellitus, it is urgent to launch a universal intervention strategy based on the promotion of a healthy lifestyle motivating regular physical activity and a low-calorie diet.

Epidemiology of arterial hypertension in Tunisia: Hammam Sousse Sahloul Heart Study (HSHS)

INTRODUCTION

Tunisia is experiencing a double burden of morbidity, characterized by the explosion of cardiovascular diseases and their risk factors including arterial Hypertension. The objective of this study, based on the HSHS cohort (Hammam Sousse Sahloul Heart Study), was to determine the prevalence of hypertension in the general population and to identify its predisposing factors.

METHODS

HSHS is a cardiovascular health promotion initiative in the city of Hammam Sousse (Tunisia). The study was conducted via a random sample of households, using the WHO PEV technique, made up of 33 clusters, of 33 households each. All people aged 20 and over, included, benefited from a questionnaire, a physical examination and a biological assessment. The Systolic Blood Pressure (SBP) and the Diastolic Blood Pressure (DBP) were measured from the average of the last two measurements, by an OMRON type tensiometer, of suitable width. These prevalences were adjusted according to sex and age group, by their weighting coefficients in the general population, and they were accompanied by their 95% CIs. Binary logistic regression was conducted to identify independent factors associated with hypertension.

RESULTS

The study population was composed of 481 men (33.4%) and 960 women (66.6%), with an average age of 49.6±16.35 years in males (M) and 46.6±16.18 in females (F). In addition to the family history of hypertension, the sufficient weekly consumption of vegetables and fruits was low (M: 32.4%, F: 24.9%). The adjusted rate of hypertension in the adult study population was 32.5%, 95%CI[31.9-33.1] (M: 36.4%, 95%CI[35, 5-37.3]; F: 28.4%; 95% CI[27.6-29.2]), reaching in the age group of 60 years and above: M: 74.6% (95%CI[66.9-82.3], F: 82.7% (95%CI[73.8-83.6]) Multivariate analysis identified five independent factors significantly associated with hypertension: male sex (ORa=1.55 [1.18-2.03]), age over 40 years (ORa=6.54[4.70-9.11]), low level of schooling (ORa=1.80 [1.36-2.38]), low physical activity (ORa=1.42[1.07-1.88]) and high socio-economic level (ORa=1 .84 [1.30-2.63]).

CONCLUSION

The HSHS study confirmed the high prevalence of hypertension, and the extent of its low detection and control. Hence the need for a universal approach to health promotion, oriented towards the general population, piloted by its local organizations, based on the adoption of a healthy lifestyle, and centered on physical activity.

Epidemiology of elderly dependency in Tunisia. HSHS study 7

AIM

Measure the functional autonomy of elderly people and identify its components and determinants in the HSHS (Hammam-Sousse Sahloul Heart Study) population (phase 2009, Tunisia).

METHODS

This study was concerned with the quality of life of elderly people aged 65 years or more, living at home from the HSHS cohort divided into two groups: young-old (65-74 years old) and old-old (≥75 years old). The autonomy was assessed using the "Activities of Daily Living" (ADL) scale ranging from 0 to 6, the "Instrumental Activities of Daily Living" (IADL) scale ranging from 0 to 8 and, the combined scale ranging from zero to 14, iso-weighted at one point per activity. Autonomy in daily activities was retained for an ADL score=6, and an IADL score (F=8; H=5). Subjects with an overall score (sum of ADL and IADL) of 10-14 points were considered globally autonomous.

RESULTS

The population study was predominantly female (sex-ratio=0,6) with an important proportion of old-old (M=43%, F=37%). Autonomy rates were by ADL (M=57.4%, F=36.1%, p < 10-2), IADL (M=16%, F=23.9%), and by combined score (M=60.6%, F=69%, p=NS). The typology of dependency was dominated by transferring (M=35%, F=61%) and bathing (M=14%, F=19%) for ADL activities, and shopping (M=36%, F=49%) and the use of means of transport (M=22%, F=43%) for IADL activities. After adjustment, autonomy in daily activities was attributed to two independent factors: male sex (ORa=3.98, CI95% [1.328-11.971]) and age group 65-75 (ORa=4.04, CI95% [2.039- 8.025]). Autonomy in instrumental activities was associated with age group (ORa=31.5, CI95% [4.087-233.514]). Finally, overall autonomy (current and instrumental) was associated independently after logistic regression, with four independent factors, two of which were not modifiable: being female (ORa=3.1, CI95% [1.2-8.1]) and 65 to 75 years (ORa=6.2, CI95% [3.1-12.3]) and two modifiable factors: no recent hospitalization (ORa=3.8, CI95% [1.4-10.4]) and a sufficient level of physical activity (ORa=2.6, CI95% [1.3-5.3]).

CONCLUSION

The physical dependency rate of the elderly is very high in Tunisia. The promotion of physical activity, the extension of similar studies and the development of could improve the support of these people.

MO920TRANSITION FROM GENERIC TO BRAND TACROLIMUS IN TUNISIAN RENAL TRANSPLANT RECIPIENTS

Background and Aims

Due to unavailability of the generic tacrolimus, commonly used in renal transplant patients in Tunisia, all renal transplant switched to the Brand. No previous studies have assessed the pharmacokinetic differences of this generic tacrolimus compared to the brand. The aim of the present study was to evaluate the effect of this switch on the tacrolimus dose (D) and on the dose-adjusted tacrolimus trough blood concentrations (C0/D) in Tunisian renal transplant recipients.

Method

For the 255 renal transplant monitored in biochemestry department of Sahloul University hospital, 808tacrolimus trough concentration (C0) were collected from october 2018 to February 2020 and were divided to 406 C0 determination before switch and 402 after switch. The dose and the post-transplantation period was recorded for each C0.

Results

The generic tacrolimus doses used were significantly higher compared to the brand: 0,12 mg/kg [0,02-0,6] vs 0,11 mg/kg [0,02-0,22] p&lt;0,001 and this was reported in different post graft periods: 0,17 [0,03-0,22] vs 0,13 [0,06-0,22] p&lt;0,001in the 3 first months after the transplantation and 0,11 [0,02-0,48] vs 0,08 [0,02-0,22] p&lt;0,001 above.The C0/D were significantly lowe runder the the generic tacrolimus compared to the brand 48,34ng/ml per mg/kg/day [11,58-210,00] vs77,35ng/ml per mg/kg/day[19,38-221,67]; p&lt;0,001 and this was reported in different post graft periods: 71,12ng/ml per mg/kg/day [6,80, 451,56] vs80,9750ng/ml per mg/kg/day [17,33-458,80] p=0,017 in the 3 first months after the transplantation and 71,12ng/ml per mg/kg/day [6,80, 451,56] vs80,9750ng/ml per mg/kg/day [17,33-458,80] p=0,017 above. Dose needed to reach target tacrolimus C0 seems to be higher with the generic tacrolimus compared to the brand.

Conclusion

Approval of a generic is dependent on bioequivalence testing in healthy adult volunteers after a single dose, however studies on renal graft recipient populations after chronic use are needed to assed bioequivalence in this special population.

MO989STUDY OF PHARMACOGENETICS OF MYCOFENOLATE MOFETIL IN KIDNEY TRANSPLANT RECIPIENTS: EXPERIENCE OF SAHLOUL HOSPITAL

Background and Aims

The pharmacokinetics and pharmacodynamics of the immunosuppressive drug mycophenolate mofetil (MMF) are subject to significant interindividual variability that affects its efficacy and toxicity. The present study focused on the genetic factors potentially involved in the variability of the response to this drug in kidney transplantation, while taking into account the influence of non-genetic factors.

Method

276 kidney transplant patients treated with MMF were involved, recruited from the Nephrology and transplantion Department of Sahloul Hospital. Data on transplantation, exposure to MMF and clinical outcomes of the patients were collected. A PCR-RFLP genetic study of 9 polymorphisms of UGT, SLCO and IMPDH was performed. Were studied the relationship between the genetic polymorphisms and the exposure to MMF, the risk of acute and chronic rejection of the kidney graft, as well as the adverse effects of MMF.

Results

This study showed that the variant alleles of polymorphisms UGT1A9 -2152C&gt;T and IMPDH II 3757T&gt;C would increase the risk of acute and chronic rejection. The variant allele of SLCO1B1 388A&gt;G would protect against acute rejection.

The variant allele of the UGT1A9 98T&gt;C polymorphism would increase the risk of diarrhea, unlike the variant allele of the UGT1A9 -275T&gt;A polymorphism, which appears to be a protective factor against diarrhea. The variant allele of the UGT1A8 518C&gt;G polymorphism would increase the risk of infections. However, relationship between genetic polymorphisms and exposure to MMF was not demonstrated.

Conclusion

These results highlight the need to take genetic variability into account in predicting the therapeutic response to MMF before initiating the treatment.

Acute rejection and genetic polymorphisms

SNP Genotype Acute rejection

Sedentary behavior, exercise and COVID-19: immune and metabolic implications in obesity and its comorbidities

Many reports showed a dramatic decrease in the levels of physical activity during the current pandemic of SARS-CoV-2. This has substantial immune and metabolic implications, especially in those at risk or with metabolic diseases including individuals with obesity and Type 2 diabetes. In this study we discussed the route from physical inactivity to immune and metabolic aberrancies; focusing on how insulin resistance could represent an adaptive mechanism to the low physical activity levels and on how such an adaptive mechanism could shift to a pathognomonic feature of metabolic diseases, creating a vicious circle of immune and metabolic aberrancies. We provide a theoretical framework to the severe immunopathology of COVID-19 in patients with metabolic diseases. We finally discuss the idea of exercise as a potential adjuvant against COVID-19 and emphasize how even interrupting prolonged periods of sitting with short time breaks of very light activity could be a feasible strategy to limit the deleterious effects of the outbreak.

Investigation of carbonic anhydrase 6 gene polymorphism rs2274327 in relation to the oral health status and salivary composition in type 2 diabetic patients

OBJECTIVE

The aim of the present study was to investigate the oral manifestations and salivary composition in type 2 diabetics with periodontitis and to evaluate their association with CA6 gene polymorphism rs2274327.

METHODS

Oral examination was performed by a single periodontist for 300 type 2 diabetics. Whole unstimulated saliva and blood were collected. The salivary pH, buffer capacity and flow rate were later measured. Immunoglobulin A and electrolytes were assessed using an autoanalyzer. CA6 gene polymorphism rs2274327 was screened by PCR-RFLP assay. The statistical analysis was performed using the SPSS 20.0 version.

RESULTS

The salivary pH, buffer capacity and flow rate were significantly lower in the patients carrying TT genotype compared to CC and CT genotype carriers (p < .05). Furthermore, the DMFT index, OHI-s, PI, PPD and CAL were significantly higher in the subjects with TT genotype (p < .05). Carrying at least one T allele seemed to increase the risk of dental caries (OR = 2.59, p < .001), xerostomia (OR = 2.11, p=.003) and taste impairment (OR = 1.97, p < .05).

CONCLUSION

CA6 gene polymorphism rs2274327 seemed to increase the risk of developing, dental caries, periodontitis, xerostomia and taste impairment in type 2 diabetics.

[Inherited kidney stones: A nephrology center experience]

INTRODUCTION

Genetic factors must be considered in etiological diagnosis of urinary lithiasis. The aim of this study was to determine clinical, metabolic characteristics and the progression of hereditary urinary lithiasis in our patients.

METHODS

A retrospective study was conducted between 2008 and 2018 and 60 patients were included. Patients were referred to our department from pediatrics departments to be followed-up in adulthood in 9 cases, for etiological investigation in 42 cases and for chronic renal failure in 9 cases.

RESULTS

Thirty-five men and twenty-five women were enrolled in this study with a M/F sex ratio equal to 1.4. The mean age at the time of diagnosis of the hereditary character of the urinary lithiasis was 28.6years (3months-63years). The average delay between the onset of the lithiasis disease and the etiological diagnosis was 8years (0-42years). We noted 31 cases of cystinuria, 18 cases of primary hyperoxaluria type 1 with two mutations (I244T in 14 cases, 33-34 Insc in 23 cases) and 11 cases of renal tubulopathy. Fourteen patients were affected with chronic renal failure, of which five were in the end-stage renal disease. Crystalluria was positive in 62% of cases. The morpho-constitutional analysis of stones was performed in 37 cases and it contributed to the diagnosis in 29 cases. After an average follow-up of 16years, we noted normal renal function in 42 cases, chronic renal failure in 7 cases, hemodialysis in 10 cases all with primary hyperoxaluria and transplantation in 1 case.

CONCLUSION

The etiological diagnosis of hereditary urinary lithiasis in our study was made with considerable delay. Cystinuria was the most frequent etiology and primary hyperoxaluria was the most serious affection.

LEVEL OF EVIDENCE

4.

Protective effects of kefir against deltamethrin-induced hepatotoxicity in rats

Deltamethrine (DLM) is a synthetic pyrethroid with broad spectrum activities against acaricides and insects. Widely used for agricultural and veterinary purposes, its human and animal exposure occurs by ingestion of contaminated water and food and leads to serious health problems. Kefir is fermented milk with numerous health favors counting restorative properties of bacterial flora, immune system stimulation, cholesterol reduction, as well as anti-mutagenic and anti-tumor properties. The present study was undertaken to examine the hepatoprotective and antioxidant potential of kefir against DLM toxicity in male Wistar albino rats. DLM-treated animals revealed a significant increase in serum biochemical parameters as well as hepatic protein and lipid oxidations but caused an inhibition in antioxidant enzymes. Additionally, we have observed an increase in hepatocyte DNA damages. This toxic effect was confirmed by histological study. Kefir administration normalized the elevated serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (T bilirubin), and cholesterol. It also reduced DLM-induced protein carbonyl (PC) and malondialdehyde (MDA) formations. Furthermore, Kefir treatment restored catalase (CAT) and superoxide dismutase (SOD) activities. The co-treatment as well as the pre-treatment by kefir showed an improvement of oxidative status as well as suppressed inflammation and DNA damages. However, the pre-treatment seems to be the most efficient. Therefore, it could be concluded that kefir is a natural product able to protect against the hepatotoxic effects of DLM by its free radical-scavenging and potent antioxidant activity.

MDR-1 and CYP3A5 Polymorphisms in Pediatric Idiopathic Nephrotic Syndrome: Impact on Susceptibility and Response to Steroids (Preliminary Results)

BACKGROUND

Oral steroid treatment is the first line of therapy for childhood nephrotic syndrome (NS). However, resistance to this treatment has been observed in some patients. Here, we investigated the association of two steroid metabolism-related genes with susceptibility to childhood NS and the steroid response.

METHODS

We genotyped the single nucleotide polymorphisms (SNP) of MDR-1 [C1236T (rs1128503), G2677T/A (rs2032582), and C3435T (rs1045642)] and the CYP3A5 gene (A6986G) in 63 NS patients and 110 age and gender matched controls by PCR-RFLP.

RESULTS

Based on multivariate logistic regression analysis carrying the G2677A A allele seemed to multiply both the risk of NS and the risk of developing glucocorticoid (GC) resistance by three-fold (OR = 3.50, [1.37 - 7.06] , p < 0.001, OR = 3.07, [1.06 - 26.10], p = 0.048, respectively). When combined into haplotype, the TAT (1236_T, 2677_A, and 3435_T) haplotype conferred a two-fold NS risk (OR = 2.26, [1.11 - 4.58], p = 0.023) and almost three-fold risk to develop resistance to GC (OR = 2.69, [1.12 - 8.79], p = 0.044). However, TAT carriers seemed to have less risk to develop NS at late age (OR = 0.34, [0.12 - 0.92], p = 0.037). The C1236T (MDR-1) and the A6986G (CYP3A5) polymorphisms showed a trend of association to GC resistance but these associations did not reach the statistical significance (OR = 2.83, [0.54 - 14.67], p = 0.294), (OR = 2.11, [0.53 - 8.38], p = 0.28), respectively.

CONCLUSIONS

Here we report that only the G2677A polymorphism was associated to NS susceptibility and steroid resistance. The TAT haplotype was associated with NS susceptibility especially at an early age and with steroid resistance.

Influence of genetic and non-genetic factors on acenocoumarol maintenance dose requirement in a Tunisian population

PURPOSE

We aimed to study potential variables involved in interindividual variability to acenocoumarol (AC) response in order to establish a pharmacogenetic algorithm (PA) that includes clinical and genetic factors to predict adequate AC dose to stabilize anticoagulation in a cohort of Tunisian patients.

METHODS

Genotyping of the CYP2C9, VKORC1, CYP4F2, and CALU polymorphisms was conducted on 246 patients using PCR-RFLP technique. AC normalized maintenance dose (NMD): ((mean maintenance dose/international normalized ratio (INR)) equilibrium) was calculated. The statistical study was carried out with SPSS V20.

RESULTS

A significant correlation was found between age, BMI, and daily AC dose (r = - 0.397; p < 0.001 and r = 0.215; p = 0.001, respectively). The carriers of mutated alleles CYP2C9*2 or CYP2C9*3 or VKORC1 haplotypes (H1 and H7) were associated with AC hyper-sensibility. After adjustment to potential covariates, these patients presented supra-therapeutic INR during treatment period and needed low AC dose (ORs* = 0.28 [0.06-0.60], p = 0.004; ORs* = 0.12 [0.04-0.05], p < 0.001; ORs* = 0.45 [0.24-0.84], p = 0.01; and ORs* = 0.28 [0.06-0.98], p = 0.049, respectively). However, carriers of VKORC1 haplotypes (H3 and H12) or mutated alleles CYP4F2 (rs2108622) or CALU (rs1043550) tend to resist to treatment, hence long period of therapy initiation, and must be treated with high AC dose (ORs* = 2.67 [81.12-5.91], p = 0.013; ORs* = 8.76 [1.07-76.26], p = 0.019; ORs* = 3.12 [1.01-9.63], p = 0.047; and ORs* = 3.96 [1.41-11.09], p = 0.009, respectively). A final multivariate regression model explained 48.1% of the global interindividual variability in AC dose requirement.

CONCLUSION

The PA demonstrated that VKORC1 and CYP2C9 polymorphisms contribution was more important than clinical factors. Applying the PA would allow dose adjustment to treat patients in a personalized manner.

Unusual clinical outcome of primary Hyperoxaluria type 1 in Tunisian patients carrying 33_34InsC mutation

Background

Primary hyperoxaluria type 1 (PH1), is a rare and heterogeneous disease and one of major causes of renal insufficiency in Tunisia, caused by mutations in the AGXT gene. 33-34InsC mutation, was mainly described in children with a severe clinical feature leading to early death, but it was uncommonly reported in adult patients.

Methods

Common mutations in AGXT were tested using PCR/RFLP technique in 111 patients (68 adult, 43 children) with suspected PH1.

Results

We described 16 cases (eight adult and eight children) with a 33-34InsC mutation with a median age of 24 years [6 months - 73 years]. All children were in end stage renal disease (ESRD) at the median age of 3 years due to lithiasis and/or nephrocalcinosis. Unfortunately, 75% of them died with a median age of 2.5 years. For the majority of adults only spontaneous elimination of urolithiasis were noted, 37.5% preserved until now a normal renal function and 62.5% of them reached ESRD at the median age of 55.8 ± 12.31 years old.

Conclusion

In this study 33-34InsC mutation gives a controversial clinical effect in children and adults. The implication of other genetic and/or environmental factors can play a crucial role in determining the ultimate phenotype.

Resistin polymorphims, plasma resistin levels and obesity in Tunisian volunteers

BACKGROUND

Adipose tissue is an important endocrine organ that secretes a number of adipokines, like Resistin (RETN); it's an adipocytes-secreted cytokine and has been proposed as a link between obesity and diabetes. Many resistin gene polymorphisms were described and their implication in obesity was controversial. This study was to investigate the prevalence of single nucleotide polymorphisms (SNPs) in RETN gene 420C/G; 44G/A; 62G/A; 394C/G and 299 G/A and their association with Resistin level and obesity in Tunisian volunteers.

METHODS

We recruited 169 nonobese (mean age=42.16-14.26 years; mean body mass index [BMI]=24.51-3.69 kg/m² ) and 160 obese (mean age=47.86-11.17 years; mean BMI=36-4.78 kg/m² ). Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism. Anthropometric parameters, lipid levels, Glycemia and insulinemia were measured, BMI was calculated and insulinresistance was evaluated with the homeostasis model assessment insulin resistance (HOMA-IR) and resistin level was measured by ELISA. Statistical analyses were performed by SPSS19.0.

RESULTS

After adjustment for confounding parameters; the Odds Ratio (OR) of obesity associated with mutated genotypes at 420C/G compared with normal genotype was as: OR=2.17; 95% CI [1.28-3.68], P=.004. The serum Resistin levels present no significant association with all RETN polymorphisms and it was significantly associated with BMI (P=.047). In our haplotype analysis, one haplotype seems to be protective and one other seems to be the highest risk to obesity.

CONCLUSION

The 420 C/G Polymorphism were associated with obesity and Leptin concentration in our population.

Genetic Variation in the Renin-Angiotensin System and Diabetic Nephropathy in the Tunisian Population

BACKGROUND

The aim of this study was to evaluate the association of ACE, angiotensinogen (AGT) and angiotensin II receptor type I (AGTR1) polymorphisms with diabetic nephropathy (DN) in Tunisians.

METHODS

The study population comprised 236 type 2 diabetic patients: with nephropathy (DN = 47) and without nephropathy (DM = 189). Genotyping of ACE-I/D-rs1799752, ACE-rs4343G>A, AGT-rs5050A>C, AGT-rs 4762C>T, AGT-rs699A>G, and AGTR1-rs5186A>C was performed by PCR-RFLP. Haplotype and statistical analysis were realized using SNP Analyzer2.0 and SPSS20, respectively.

RESULTS

Genotype frequencies were in Hardy-Weinberg equilibrium. After adjustment for potential confounding factors (age, gender, diabetes duration, hypertension…), an increased risk for DN was associated with mutated alleles of rs4762 (OR = 10.25, p = 0.001), rs699 (OR = 22.21, p < 0.001), and rs5186 (OR = 11.25, p < 0.001). However, mutated alleles of rs1799752 seemed to be protector (OR = 0.41, p = 0.011). Adjusted ORs of DN associated with the ACE haplotype (DA) was (OR = 9.56, p = 0.047) and with the ACE-AGT haplotype (ATADAA) was (OR = 5.38, p = 0.032).

CONCLUSIONS

This study indicates that common variants in ACE, AGT, and AGTR1 seem to play a role in genetic susceptibility to DN in Tunisian population and provides evidence for a disease haplotype: ATADAA.

Association of ADIPOQ, leptin, LEPR, and resistin polymorphisms with obesity parameters in Hammam Sousse Sahloul Heart Study

BACKGROUND

Adipose tissue is an important endocrine organ that secretes a number of adipokines, such as adiponectin (ADIPOQ), leptin (LEP), leptin receptor (LEPR), and resistin (RETN) which may be implicated in obesity. Some adipokines' polymorphisms of genes might influence their concentrations and/or activities. Our aim was to study the relationship between seven SNPs in ADIPOQ (+45T<G (rs2241766); +276G<T (rs1501299); -4255C<T (rs822393); -395G<T (rs17366568)), LEP (2548G<A (rs7799039)), LEPR (223Q<R (rs1137101)), and RETN (-420C<G (rs1862513)) and obesity in Hammam Sousse Sahloul Heart Study (HSHS).

METHODS

The study, carried out between February and June 2009, is mainly focused on 1121 respondents in HSHS which is a population-based epidemiological study of type "community-based" on cardiovascular risk. Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Serum lipids and anthropometric parameters were measured. Statistic analysis was performed on SPSSv19.

RESULTS

The polymorphisms of ADIPOQ 4522C<T and 276G<T, LEP 2548G<A, and RETN 420C<G seem to contribute to obesity. In fact, adjusted odds ratios (ORs) of obesity associated with mutated genotypes of each polymorphism were respectively OR=1.38, P=.037; OR=0.608, P<.001; OR=2.23, P=.034; and OR=2.18, P<.001. The 276G<T, 4522C<T, and 420C<G were associated with increased BMI (P=.010, P=.028, and P<.001). A significant association was found between the 276G<T; 4522C<T, LEP 2548G<A and 420C<G, and the waist circumference and hip measurements.

CONCLUSION

ADIPOQ, LEP, and RETN gene polymorphisms were associated with obesity parameters in HSHS population.

Mutational Analysis of Agxt in Tunisian Population with Primary Hyperoxaluria Type 1

BACKGROUND

Primary hyperoxaluria type 1 (PH1) is an autosomal recessive metabolic disorder caused by inherited mutations in the AGXT gene encoding liver peroxisomal alanine:glyoxylate aminotransferase (AGT). PH1 is a clinically and genetically heterogeneous disorder. The aim of our study was to analyze and characterize the mutational spectrum of PH1 in Tunisian patients.

MATERIALS AND METHODS

Molecular studies of 146 Tunisian patients suspected with PH were performed by PCR/Restriction fragment length polymorphism (RFLP) to detect seven mutations described as the most common. Direct sequencing for the 11 exons was performed in patients in whom any mutation was not identified.

RESULTS

The genetic diagnosis of PH1 was confirmed in 62.3% of patients. The first molecular approach based on PCR/restriction enzyme test was positive in 37.6% of patients, whereas the second molecular approach based on whole gene sequencing was successful in 24% of cases. Twelve pathogenic mutations were detected in our cohort. Two mutations were novel, and five were detected for the first time in Tunisians. The three most frequent mutations were p.Ile244Thr, p.Gly190Arg, and c.33dupC, with a frequency of 43.4%, 21.4%, and 13.1%, respectively.

CONCLUSION

The two novel mutations detected in our study extend the spectrum of known AGXT gene mutations. The screen for the mutations identified in this study can provide a useful, cost-effective, and first-line investigation in Tunisian PH1 patients.

HOGA1 Gene Mutations of Primary Hyperoxaluria Type 3 in Tunisian Patients

BACKGROUND

Primary hyperoxaluria type 3 (PH3) is due to mutations in the recently identified 4-hydroxy-2-oxoglutarate aldolase (HOGA1) gene. PH3 might be the least severe form with a milder phenotype with good preservation of kidney function in most patients. The aim of this study was to report three PH3 cases carrying mutations in HOGA1.

MATERIALS AND METHODS

Genetic analysis of HOGA1 was performed in patients with a high clinical suspicion of PH after sequencing of AGXT and GRHPR genes, which was negative. Also, a complete AGXT/GRHPR MLPA was performed in these patients in order to detect large deletions/insertions.

RESULTS AND DISCUSSION

Two different HOGA1 gene mutations were identified: the p.Pro190Leu in a homozygous state and the p.Gly287Val in two patients in homozygous and heterozygous carriers. The median age at onset of clinical symptoms was 3.93 years. Most of the patients had a positive family history for recurrent urolithiasis. The p.Pro190Leu mutation was reported with impaired renal function at follow-up; however, the p.Gly287Val was presented with normal renal function. All patients were presented with urolithiasis, but only one had a nephrocalcinosis.

CONCLUSION

This study expanded the number of PH3 patients from 63 to 66 cases. The p.Pro190Leu and the p.Gly287Val mutations found in this study can provide a first-line investigation in Tunisian PH1 patients.

CT genotype of 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism is protector factor of major depressive disorder in the Tunisian population: a case control study

BACKGROUND

Major depressive disorder (MDD) is a common psychiatric disorder with considerable mortality. Death from unnatural causes, largely suicidal or quasi-suicidal, has a particularly high risk for the functional disorders, especially depression and schizophrenia. One of the prospective risk factors for this disease is hyperhomocysteinemia and folate deficiency. The methylenetetrahydrofolate reductase (MTHFR) gene encodes for a 5-methylenetetrahydrofolate reductase involved in folate metabolism and neurotransmitter synthesis. The aim of this research is to study the association between the C677T polymorphism of MTHFR gene and depression in Tunisian population, to explore their relationship with clinical and therapeutic characteristics of this disease. And it may lead to discover a novel marker to identify a patient with a higher risk of development of depressive disorder to be. This marker can be used for better therapeutic management and prevent disease installation.

METHODS

Our study included 208 depressive patients, 187 controls aged between 44.1 ± 13.5 and 38.9 ± 13.2 years, respectively. MTHFR gene polymorphisms were determined by PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism).

RESULTS

No significant difference was detected in the distribution of the genotype frequencies of MTHFR C677T polymorphisms (χ (2) = 5.443, df = 2, p = 0.066) between patients and controls. But when we study the risk of these genotypes, CT genotype is significantly more frequent in controls compared to patients, it may be a protection from depression (OR = 0.655, CI 95 % = 0.432-0.995, p = 0.047, OR* = 0.638, CI 95 %* = 0.415-0.983, p* = 0.04, before and after adjustment). Women, TT Genotype can increase four times the risk to be depressive. Addictive behavior seems to be associated with CT genotype and there was no significant association between clinical and therapeutic characteristics and this polymorphism.

CONCLUSION

This paper is the first study to prove that CT genotype of MTHFR C677T polymorphism may protect from depression and TT genotype seems to be associated with women's depression. Further studies are required with other polymorphisms and biochemical factors that must be investigated to clarify the implication of MTHFR C677T polymorphism in the pathophysiology of depression.

Four polymorphisms of cholesteryl ester transfer protein gene and coronary stenosis in a Tunisian population

AIMS

The role of cholesteryl ester transfer protein (CETP) in the development of atherosclerosis is under debate. We studied the association of four polymorphisms (Taq1B, I405V, R451Q and A373P) in the CETP gene with lipid profile and coronary artery disease.

METHODS

Four CETP polymorphisms were studied in 316 Tunisian patients undergoing coronary angiography. Patients were clinically examined and their lipid profiles were estimated. Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism analysis.

RESULTS

The 451Q allele, associated with lower high-density lipoprotein-cholesterol (HDL-C) and higher total cholesterol and apolipoprotein B (ApoB) concentrations, was also significantly associated with an increased risk of significant stenosis [odds ratio (OR) = 1.74, 95% confidence interval (CI) 1.15-2.61, P = 0.007]. The B2 allele of Taq1B polymorphism had an increase in HDL-C concentration and was associated with a decreased risk of coronary stenosis, as described earlier. It was also associated with low risk of hypoHDLaemia [OR = 0.615, 95% CI 0.377-1.002, P = 0.035]. No significant effect of different A373P and I405V alleles was found on the lipid profile and on coronary stenosis. When CETP polymorphisms were combined in haplotypes possessing R451Q, A373P, I405V, Taq1B polymorphisms, the 1112 haplotype (where 1 is the wild genotype and 2 represents carriers of the variant allele) seems to be the most protective against significant stenosis (OR = 0.71, 95% CI 0.188-0.983; P = 0.014), whereas 2111 was probably the most atherogenic, with an OR = 2.17, 95% CI 1.06-5.88; P = 0.039.

CONCLUSION

The Q allele of the R451Q polymorphism was associated with decreased HDL-C, increased ApoB concentrations and increased risk of coronary stenosis. In haplotype analysis, we found that 1112 seems to be a protective haplotype, whereas 2111 has an atherogenic effect in a coronary Tunisian population.

Association of three polymorphisms of scavenger receptor class BI gene (exon8, exon1, intron5) with coronary stenosis in a coronary Tunisian population

BACKGROUND

The potential role of scavenger receptor class BI (gene name SCARB1) in the regulation of lipoproteins metabolism and atherosclerosis has attracted considerable interest. We tested the relationship of SCARB1 polymorphisms with significant coronary stenosis (SCS) and lipid profile in a coronary Tunisian population.

METHODS

Three SCARB1 polymorphisms (exon8 (C/T), exon1 (G/A), intron5 (C/T)) were studied in 316 Tunisian patients undergoing coronary angiography. SCS was defined as a luminal narrowing of ≥ 50% in at least one major coronary artery. Lipid profile was measured. Genotyping was performed using PCR-RFLP.

RESULTS

Individuals with TT genotypes of exon8 were associated with higher concentrations of plasma HDL-C and ApoAI in the group without SCS. Carriers of T allele of exon8 were associated with 41% lower risk of SCS. This protective effect seemed to be particularly significant in women, nondiabetics and nonsmokers. Subjects homozygous for the variant allele of intron5 were significantly associated with an increased risk of SCS, particularly in smokers. AA genotype of exon1 was associated with an increased risk of SCS in diabetics and in patients with metabolic syndrome. The (CAT) haplotype was associated with increase in the risk of SCS compared to the wild haplotype and had a 4-fold greater risk of SCS than patients with haplotype (TGC) which seems to be the most protective against SCS.

CONCLUSION

Carriers of T allele of exon8 in SCARB1 seemed to increase HDL-C and ApoAI concentrations and reduce the risk of SCS. The intron5, exon1 and (CAT) haplotype seemed to have an atherogenic effect.

Association of PON1 and PON2 polymorphisms with PON1 activity and significant coronary stenosis in a Tunisian population

PON1 and PON2 have attracted considerable attention as candidate genes for coronary heart disease because their enzymes function as key factors in lipoprotein catabolism pathways. We studied the distribution of PON1 and PON2 polymorphisms, including genotyping, lipid profile, and PON1 activity, and their association with PON1 activity and significant coronary stenosis (SCS) in a Tunisian population. PON1 activity was lower in patients with SCS than in controls. It increased with the R allele (QQ < QR < RR) in PON1-192 genotypes and with the L allele (MM < ML < LL) in PON1-55 genotypes. In the presence of metabolic syndrome and diabetes, PON1-192RR and PON2-311CC were associated with an increased risk of SCS and PON1-55MM seems to have lower risk. This association was evident among nonsmokers for PON1-55MM and among smokers for PON1-192RR and PON2-311CC. The GTGC haplotype seemed to increase the risk of SCS compared with the wild haplotype in a Tunisian population.

Association between four resistin polymorphisms, obesity, and metabolic syndrome parameters in Tunisian volunteers

Resistin is an adipocyte-secreted cytokine recently discovered and has been proposed as a link between obesity and diabetes. Many resistin gene polymorphisms were described and their implication in obesity and metabolic syndrome (MetS) was controversial. Our aim was to study the relationship between four resistin polymorphisms (420C/G, 44G/A, 62G/A, and 394C/G), MetS parameters, and the risk of obesity in Tunisian volunteers. We recruited 169 nonobese (sex ratio=0.594; mean age=43.25±13.12 years; mean body mass index [BMI]=24.73±3.50 kg/m(2)) and 160 obese subjects (sex ratio=0.221; mean age=48.41±10.92 years; mean BMI=36.6±4.8 kg/m(2)). Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism. Anthropometric parameters, lipid levels, glycemia, and insulinemia were measured. BMI was calculated and insulin resistance was evaluated with the homeostasis model assessment insulin resistance (HOMA-IR). Statistical analyses were performed by SPSS 17.0. The 420C/G seems to contribute to obesity. In fact adjusted odds ratio (OR) of obesity associated to mutated genotypes was 2.17 and 95% confidence interval was 1.28-3.68 (p=0.004). Mutated genotypes at 420C/G were associated with higher waist circumference and BMI. In addition, 44G/A polymorphism was associated with increased total cholesterol and low-density lipoprotein-cholesterol levels. The other genotypes showed no association with MetS parameters. Concerning association between single-nucleotide polymorphisms and MetS risk, only mutated genotypes at 44G/A increase the risk of MetS after adjustment to confounding parameters (OR=1.93, p=0.023). In conclusion, resistin gene polymorphisms 420C/G and 44G/A were associated with obesity and MetS parameters in Tunisian volunteers.

Relationship between leptin G2548A and leptin receptor Q223R gene polymorphisms and obesity and metabolic syndrome risk in Tunisian volunteers

Leptin is a key hormone of weight regulation that modulates food intake. Since the elaboration of the leptin action mechanism, several studies tried to establish the relationship between obesity and the common polymorphisms of leptin (LEP) and leptin receptor (LEPR) genes, but results were controversial. We studied the association of G2548A of the LEP gene and Q223R of LEPR gene polymorphisms with obesity and metabolic syndrome (MetS). We recruited 169 nonobese volunteers (body mass index [BMI] < 30 kg/m(2)) and 160 obese ones (BMI ≥ 30 kg/m(2)). Glucose, insulin, and lipids were measured. BMI, homeostasis model assessment-insulin resistance (HOMA-IR), and daily energy intake were calculated. After adjustment to confounders parameters, 2548AA was found to increase the MetS (p=0.043) and obesity risk (p=0.019) in the studied population. After stratification according to the degree of obesity, the odds ratio [OR] of 2548AA was associated with moderate obesity (p=0.048) and morbid obesity (p=0.048). The LEPR 223RR genotype was associated with obesity in the studied population (OR=1.74, p=0.037) and only in the overweight (OR=1.8, p=0.049). Subjects with 2548AA had significantly higher BMI, daily energy intake, total cholesterol (TC), waist circumference (WC), insulinemia, and low high-density lipoprotein-cholesterol (HDL-C) levels. With regard to 223RR, we noted a significantly higher daily energy intake, BMI, TC, glycemia, insulinemia, HOMA-IR index, and low HDL-C levels. Haplotype model AR (2548A+223R) and AQ (2548A+223Q) increased the risk of obesity (OR=3.36, p<0.001; OR=2.56, p=0.010, respectively). When we added daily energy intake in adjustment, these significant associations disappeared. In addition, the AR and AQ increased the MetS risk. This significant association persisted after we had added daily energy intake in adjustment. This study showed that LEP G2548A and LEPR Q223R polymorphisms and haplotype combination were associated with MetS and obesity risk in Tunisian volunteers.

Association between bipolar I disorder and the L55M and Q192R polymorphisms of the paraoxonase 1 (PON1) gene

BACKGROUND

The purpose of this work was to study the association between the PON1 L55M and Q192R polymorphisms and bipolar I disorder in Tunisian patients and to explore their relation to the sociodemographic, clinical and therapeutic characteristics of this disease.

PATIENTS AND METHODS

Our study included 109 patients with bipolar I disorder and 110 controls aged 39.4±11.8 and 37.3±9.2 years, respectively. L55M and Q192R of the PON1 gene polymorphisms were determined by multiplex polymerase chain reaction.

RESULTS

Significant difference was detected in the distribution of the genotype frequencies of L55M and Q192R polymorphisms (χ²=6.32, df=2, p=0.04; χ²=10.15, df=2, p=0.006 respectively) between patients and controls. We noted significant association between bipolar I disorder and QR and RR genotypes (OR 2.06, CI 95% 1.10-3.84, p=0.02; OR 1.72, CI 95% 1.07-2.75, p=0.02 respectively) and between this disease and LM and MM genotypes (OR 2.22, CI 95% 1.19-4.15, p=0.012; OR 3.04, CI 95% 1.60-5.77, p=0.01 respectively). There were no significant differences in gender, age at onset, illness episode and treatment among all genotypes. However, Q192R polymorphism was significantly associated with age and patients with RR genotype were the youngest.

CONCLUSION

Bipolar I disorder was significantly associated with L55M and Q192R polymorphisms, suggesting that these polymorphisms may play a role for development of bipolar I disorder. There was no significant association between the clinical and therapeutic characteristics of this population and these polymorphisms. Further studies are required to clarify the implication of these polymorphisms in the pathophysiology of bipolar I disorder.

Effect of mutations in LDLR and PCSK9 genes on phenotypic variability in Tunisian familial hypercholesterolemia patients

BACKGROUND

Autosomal dominant hypercholesterolemia (ADH) is commonly caused by mutations in the low-density lipoprotein (LDL) receptor gene (LDLR), in the apolipoprotein B-100 gene (APOB), or in the proprotein convertase subtilisin kexine 9 gene (PCSK9). ADH subjects carrying a mutation in LDLR present highly variable plasma LDL-cholesterol (LDL-C). This variability might be due to environmental factors or the effect of some modifying genes such as PCSK9 and APOE.

AIMS

We investigated the molecular basis of thirteen Tunisian ADH families and attempted to determine the impact of PCSK9 and APOE gene variations on LDL-cholesterol levels and on the variable phenotypic expression of the disease.

METHODS AND RESULTS

Fifty six subjects were screened for mutations in the LDLR gene through direct sequencing. The causative mutation was found to segregate with the disease in each family and a new frameshift mutation, p.Met767CysfsX21, was identified in one family. The distribution of total- and LDL-cholesterol levels, adjusted for age and gender, among homozygous and heterozygous ADH patients varied widely. Within seven families, nine subjects presented low LDL-cholesterol levels despite carrying a mutation in the LDLR gene. To identify the molecular actors underlying this phenotypic variability, the PCSK9 gene was screened using direct sequencing and/or enzymatic restriction analysis, and the apo E genotypes were determined. A new missense variation (p.Pro174Ser) in the PCSK9 gene was identified and characterized as a new putative loss-of-function mutation.

CONCLUSION

Genetic variations in PCSK9 and APOE genes could explain only part of the variability observed in the phenotypic expression in Tunisian ADH patients carrying mutations in the LDLR gene. Other genetic variants and environmental factors very probably act to fully explain this phenotypic variability.

Effect of cigarette smoking on paraoxonase 1 activity according to PON1 L55M and PON1 Q192R gene polymorphisms

OBJECTIVE

This study aims to investigate the effect of cigarette smoking on paraoxonase 1 (PON1) activity according to PON1 L55M and PON1 Q192R gene polymorphisms.

MATERIALS AND METHODS

Our sample included 300 voluntary subjects: 138 nonsmokers and 162 current smokers aged 38.47 ± 21.91 and 35.55 ± 16.03 years, respectively. PON1 activity was determined by kinetic methods. L55M and Q192R gene polymorphisms of PON1 were determined by multiplex polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP).

RESULTS

We found in smokers a significant decrease of PON1 activity before and after adjustment. We noted a significant association between smoking status and lower PON1 activity [odds ratio (OR) = 3.03, confidence interval 95% = 1.5-5.9, p = 0.001]. In smokers, there was significant association between PON1 activity and PON1 L55M polymorphisms (p = 0.01). Also, the 55MM genotype presented the lowest paraoxonase activity, while the 55LL genotype showed the highest one. After adjustment for confounding variables, smokers with PON1 L55M polymorphism had the highest risk for lower PON1 activity; however, PON1 Q192R genotype might protect smokers from decrease in PON1 activity. We found significant interaction between the effect of cigarette smoking and both PON1 L55M and PON1 Q192R polymorphisms on lower PON1 activity.

CONCLUSIONS

Cigarette smoking was significantly associated with decrease in PON1 activity. Moreover, PON1 L55M polymorphism predisposes smokers to decreased PON1 activity in contrast to PON1 Q192R genotype.