[Incidence Analysis of Monoclonal Gammopathy of Undetermined Significance in People over 40 Years of Age].

OBJECTIVE: To study the distribution of monoclonal gammopathy of undetermined significance(MGUS) in different age, sex and ethnic people over 40 years old. METHODS: Five hundred and ninety-six people(over 40 years old) examened in the Health Examination center of the First Affiliated Hospital of Xinjiang Medical University from July 2017 to September 2017 were selected. Among 596 people, male 310, female 286, Han people 488, and Uygur ethnic people 108. According to age, 596 people were divided into 3 groups, (40-59 years old group, 60-79 years old group, over 80 years old group). First, all samples were screened by capillary serum protein electrophoresis. If the suspected monoclonal bands were found in the electrophoretogram, and then the specific protein types were determined by serum immunofixation electrophoresis. RESULTS: The total incidence of MGUS in 596 screened population was 4.027%. The incidence of MGUS in 40-59 years old group, 60-69 years old group and over 80 years old group were 1.762%, 2.929% and 10% respectively, and the differences among the groups were statistically significant(P<0.05). The incidence of MGUS in male (5.806%) was significantly higher than that in female (2.097%)(χ2=5.177，P<0.05). Binary Logistic regression analysis showed that over 80 years old and male were independent risk factors for MGUS(P=0.001, OR=4.188, 95%CI: 1.814-9.673, P=0.048, OR=2.605, 95%CI: 1.009-6.725). The types of immunoglobulin in patients with MGUS were mostly IgG, IgG(66.7%) was significantly more than IgA (29.2%)(χ2=21.375，P<0.05)，and there was no significant difference in the incidence of MGUS between people with in Kappa and Lambda. CONCLUSION: The age increase and male may increase the incidence of MGUS, the IgG is the most common type of immunoglobcdin in pathogenesis of MGUS, so the early screening should be done.