Polymorphisms of methylenetetrahydrofolate reductase (MTHFR) and susceptibility to pediatric acute lymphoblastic leukemia in a German study population.

BACKGROUND: Methylenetetrahydrofolate reductase (MTHFR) has a major impact on the regulation of the folic acid pathway due to conversion of 5,10-methylenetetrahydrofolate (methylene-THF) to 5-methyl-THF. Two common polymorphisms (677C>T and 1298A>C) in the gene coding for MTHFR have been shown to reduce MTHFR enzyme activity and were associated with the susceptibility to different disorders, including vascular disease, neural tube defects and lymphoid malignancies. Studies on the role of these polymorphisms in the susceptibility to acute lymphoblastic leukemia (ALL) led to discrepant results. METHODS: We retrospectively evaluated the association of the MTHFR 677C>T and 1298A>C polymorphisms with pediatric ALL by genotyping a study sample of 443 ALL patients consecutively enrolled onto the German multicenter trial ALL-BFM 2000 and 379 healthy controls. We calculated odds ratios of MTHFR genotypes based on the MTHFR 677C>T and 1298A>C polymorphisms to examine if one or both of these polymorphisms are associated with pediatric ALL. RESULTS: No significant associations between specific MTHFR variants or combinations of variants and risk of ALL were observed neither in the total patient group nor in analyses stratified by gender, age at diagnosis, DNA index, immunophenotype, or TEL/AML1 rearrangement. CONCLUSION: Our findings suggest that the MTHFR 677C>T and 1298A>C gene variants do not have a major influence on the susceptibility to pediatric ALL in the German population.

Screening for arthrofibrosis after anterior cruciate ligament reconstruction: analysis of association with human leukocyte antigen.

PURPOSE: Arthrofibrosis represents a severe complication of trauma and reconstructive joint surgery because of generalized connective tissue proliferation resulting in painful joint stiffness. It often appears stereotypical in terms of its clinical and pathologic features, comprising excess deposition of extracellular matrix proteins such as collagen type I, III, and VI and proliferation of fibroblasts. However, trauma and surgery around joints does not always lead to fibrosis, suggesting a genetic predisposition. For a number of autoimmune diseases, strong associations have been described. The objective of the study was to investigate whether an association of HLA (human leukocyte antigen) with primary arthrofibrosis exists. TYPE OF STUDY: Retrospective cohort study. METHODS: Seventeen patients with primary arthrofibrosis after autologous anterior cruciate ligament (ACL) reconstruction were identified and clinically reviewed. Blood samples were taken, and DNA was isolated by column extraction method. DNA samples were typed for the loci HLA-A, -B, -C, -DRB1, and -DQB1. Results were compared with the frequencies of allelic groups as determined for the caucasoid population. RESULTS: HLA-Cw*07 was significantly less often found in the patient group than in the general population (P =.022). The opposite effect was seen for Cw*08, which was found in 17.6% of the patient group but only in 3.8% of the reference group (P =.045). A significant difference was also seen for DQB1*06, because 23.5% of the patients but 48.6% of the reference group possessed an allelic variant of this group (P =.048). However, according to the relatively small number of patients, a statistical bias cannot be excluded. CONCLUSIONS: A possible link may exist between arthrofibrosis and HLA-Cw*07- and DQB1*06-negative as well as Cw*08-positive individuals. Further investigation is necesessary to confirm or vitiate the possible association. LEVEL OF EVIDENCE: Level IV.