RÉSUMÉ
Objective:To investigate the clinical relationship between homocysteine (Hcy) metabolizing enzyme gene polymorphism and poor prognosis of multiple myeloma (MM) in Han nationality.Methods:One hundred and twenty-eight MM patients of Han nationality admitted to the First Affiliated Hospital of Hebei North University from February 2018 to March 2020 were selected as the disease group, and 120 healthy volunteers of Han nationality were recruited as the control group at the same time. Blood samples were taken to detect plasma Hcy level and Hcy metabolizing enzyme gene polymorphism, including methylenetetrahydrofolate reductase(MTHFR) C677T, MTHFRA1298C, methionine synthase reductase(MTRR) A66G, cystathionine beta-synthase(CBS) 844ins68 and methionine synthase (MS) A2756G. The patients in the disease group were treated with conventional methods , followed up for 1 year after treatment, and the incidence of poor prognosis was counted. Plasma Hcy level, genotype distribution and allele frequency of Hcy metabolic enzymes were compared between the two groups. Logistic multiple regression analysis was used to analyze the association of Hcy metabolizing enzyme gene polymorphism with MM poor prognosis in Han nationality.Results:The plasma Hcy level in the disease group was higher than that in the control group: (15.01 ± 2.98) μmol/L vs. (8.45 ± 1.69) μmol/L, there was statistical difference ( P<0.05). The frequency of TT genotype and T allele of MTHFRC677T locus in the disease group were higher than those in the control group : 26.56% vs. 6.67% , 29.30 vs. 16.25%; while the frequency of CT genotype in the disease group was lower than that in the control group: 5.47% vs. 19.17% , there were statistical differences ( P<0.05). There were no significant differences in genotype distribution and allele frequency of other gene loci between the two groups ( P>0.05). The incidence of poor prognosis in the disease group was 49.22%(63/128). Age, platelet count, serum β 2 microglobulin level, serum κ light chain level, plasma Hcy level and TT genotype of MTHFRC677T locus were the influencing factors of poor prognosis in the disease group ( OR = 7.286, 0.545, 6.841, 6.284, 8.117 and 8.440; P<0.05). Conclusions:The plasma Hcy level, TT genotype and T allele frequency of MTHFRC677T locus in MM patients of Han nationality are higher than those in healthy people, while the CT genotype frequency is lower than that in healthy people. The poor prognosis of MM in Han nationality is related to plasma Hcy level and TT genotype of MTHFRC 677T locus.