Methotrexate (MTX) is a key component of acute lymphoblastic leukemia (ALL) therapy, but it is associated with serious toxicities in a considerable number of patients. The aim of the current study was to determine which variables were associated with MTX toxicity in children, adolescents and young adults with ALL. In this prospective study, 35 patients with newly diagnosed ALL, treated according to the 58951 European Organization for Research and Treatment of Cancer - Children's Leukemia Group (EORTC-CLG) protocol, were prospectively enrolled. Toxicity data was collected objectively after each high-dose methotrexate (HD-MTX) course. The risk factors of MTX toxicity were determined using multiple linear regression analysis, with age, gender, immunophenotype, risk group, plasma MTX levels, plasma homocysteine (HCY) levels, and MTHFR C677T included as independent variables. Twenty-five (71.4%) patients experienced toxicity on at least 1 course of HD-MTX. In the univariate linear regression, the global toxicity score was associated with a significant rise in plasma HCY concentrations within 48 h after MTX administration (β = 0.4; R2 = 0.12; p = 0.02). In the multiple regression model, the global toxicity score was significantly associated with a higher MTX plasma levels at 48 h (β = 0.5; R2 = 0.38; p = 0.001) and CT 677 MTHFR genotype (β = 0.3; R2 = 0.38; p = 0.01). Routine monitoring of plasma MTX concentrations is essential to detect patients at a high risk of MTX toxicity. MTHFR C677T genotyping may be useful for predicting MTX toxicity.

Knee Osteoarthritis is a considerable public health concern, both in terms of life quality and treatment financial impacts. To investigate this disease, animal models are deemed a promising alternative. In fact, although a perfect model is generally farfetched, the creation of models that simulate human disease as accurately as possible remains an important research stake. This study aims to highlight the usefulness of the model induced by injected Mono-Iodo-Acetate and to standardize it for the rabbit species. Osteoarthritis was induced by an infra-patellar injection of 0.2 ml of an MIA solution in the left knee of 24 female New Zealand rabbits. The right knee served as a control by receiving an injection of physiological serum. The rabbits were divided into 4 groups of 6 individuals each according to the dose of MIA received per knee. All rabbits were euthanized 30 days after the injection. After sacrifice, the knees were carefully dissected and macroscopic and microscopic scores of cartilage, meniscal and synovial lesions were attributed to each group. Our study followed the laboratory animal care and management guideline published in 2017 by the Canadian Council of Animal Care. The control knees of all rabbits showed no macroscopic or microscopic lesions. The macroscopic lesions: osteophytes, meniscal lesions, fibrillation and erosion of the cartilage and microscopic lesions: disorganization of the chondrocytes, decrease in proteoglycans and synovial inflammation clinically diagnosed in human pathology were all detected and were similarly reproducible among the knees of the same group. Through this work, we highlighted the merits of the arthritis model induced by MIA, namely its simulation of several aspects of human pathology. Further advantages are low cost, speed, reproducibility. This model notably avoids delicate and risky surgical operations.

Context: Methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms, mainly the C677T, have been implicated as risk factors for several cancers as the acute lymphoblastic leukemia (ALL). In addition, a potential effect of such variant on the efficacy of methotrexate (MTX) has been reported. Objective: In this study, we evaluated the impact of the C677T variant of MTHFR on MTX-related toxicity in ALL patients from Tunisia; to provide new insights for a personalized therapy based on the human genotype. Materials and methods: Genotyping was carried out with restriction fragment length polymorphism (RFLP) on blood samples from a total of 35 younger patients; suffering from ALL. Results: In the ALL patients, the MTHFR 677CT genotype confers a greater risk of toxicity with 1.3 times as relative risk mainly the hepatic toxicity when compared with MTHFR 677CC. Conclusion: Our findings suggest that C677T polymorphism of MTHFR seems to be a good marker for MTX-related toxicity in ALL.

Objective: The methylenetetrahydrofolate reductase gene C677T polymorphism is closely related to the acute lymphoblastic leukemia. Several case–control studies have investigated this association; however, no conclusions could be drawn. A comprehensive updated meta-analysis is established to explain these contradictions and clarify the overall impact of this variant on the susceptibility to acute lymphoblastic leukemia. Methods: Electronic searches were conducted to select published studies prior to June 2018. Pooled odds ratios and stratification analysis were performed under different genetic comparison models, age, and ethnicity. Results: Totally, 66 case–control studies including 9619 acute lymphoblastic leukemia cases and 17,396 controls were selected. Our analyses showed that methylenetetrahydrofolate reductase C677T polymorphism was protective mainly in Asian and European countries, under all genetic models and regardless of age, but leukemogenic in mixed population. Conclusion: Thus, C677T polymorphism may be a promising acute lymphoblastic leukemia biomarker, but they should be interpreted with caution considering other factors such as folic acid intake, gene–gene and gene–environment interactions.

Background: Inherited thrombophilia, mainly the Factor V Leiden (FVL) and Prothrombin mutation (PTM) are the most risk factors for venous thrombosis especially during pregnancy and was strongly associated with recurrent pregnancy loss (RPL), a devastating reproductive problem that affects more than 1% of couples who are trying to conceive. The frequencies also the correlation among these polymorphisms and RPL have been reported controversially in various populations.Objectives: In this study we evaluated the presence inherited thrombophilia amongst 35 Tunisian women with more than 2 miscarriages, referred to our genetic counseling.Methods: DNA was extracted from peripheral blood samples and PCR-RFLP was performed for the molecular diagnosis ofmutation.Results: FVL and PTM were detected in 5.7 % and 2.9% respectively; in women with a particular history of early fetal loss andthrombotic events.Conclusion: This study emphasizes the importance of testing for FVL and FIIM in women with RPL; mainly in the context of thrombotic events. Multi-center collaboration is necessary to clarify the real impact of thrombotic molecular defects on the pregnancy outcome, to ascertain the effect of inherited thrombophilia on recurrent pregnancy loss and then to evaluate the appropriate therapeutic approach.

Background: Methotrexate (MTX) is a key drug in acute lymphoblastic leukemia (ALL) treatment; it inhibits DNA replication by blocking the conversion of 5, 10 Methylenetetrahydrofolate to 5-methylene tetrahydrofolate by methylenetetrahydrofolate reductase (MTHFR). Variants of the Methylenetetrahydrofolate reductase (MTHFR) and MTX related toxicities were largely investigated in several populations, nevertheless, the results are conflicting. Objective: This study aimed to assess the prevalence of MTHFR SNVs: C677>T and A1298>C in Tunisian patients with ALL and the relation to the frequency of drug-induced complications. Methods: 28 ALL patients were included in the study. They were treated according to EORTOC, in which a high dose of MTX (HDMTX) was prescribed. A toxicity score (ST) is calculated for each patient, summing the grades of toxicities. Genotyping of MTHFR variants was done with a PCR-based restriction fragment length polymorphism assay. Results: The toxicity’s score (TS) was higher with C677T variant compared to wild genotype (C677C) (TS = 4; IC95% [−2.65–13.32] versus TS = 2.5; IC95% [1.65–4.55], respectively; p = 0.2); but lower with the A1298C mutation compared to those with the wild genotype (A1298A) (TS = 2.5; IC95% [0.48–4.77], versus TS =3; IC95% [1.9–5.69], p = 0.4). HDMTX-related toxicity is associated with the 677CT genotype in ALL patients (RR = 1.41, p = 0.2); not for the A1298C [OR = 0.46, [0.08–2.61], p = 0.18]. Conclusion: Our preliminary findings highlight the impact of the C677T variant of MTHFR, but not the A1289C; in HD-MTX chemotherapy-related adverse effects in younger Tunisian ALL.