A Study On The FCRL Genetic Susceptibility And Gene-environment Interaction Of Ankylosing Spondylitis

Objective To analyze FCRL genetic susceptibility and environmental factors of ankylosing spondylitis, and explore the gene-environmental interaction role in ankylosing spondylitis, in order to provide a scientific basis for the etiology research and prevention of ankylosing spondylitis.Methods 165 AS outpatients were selected from the department of rheumatism and immunity of a Grade III Level A hospital in Anhui province, and 184 cases of healthy blood donors were selected as controls the same period. The questionnaire was designed according to the Bath AS functional index and the total backache index. The demographic characteristics (sex, age, nation and occupy), laboratory test results and environmental factors exposure (smoking, drinking, diet and infection history) were investigated. The peripheral blood (5ml) of outpatients and controls were anticoagulanted by EDTA and the plasma were segregated. DNA were extracted by salting-out method. The objective gene was amplified by PCR, and FCRL gene cluster single nucleotide were screened and identified by LDR. A case-control study method was used to analyze genetic susceptibility, while a multinomial Logistic regression was used to analyze the factors of total bachache degree and BASFI index of AS patients. The interaction between FCRL3, FCRL5 gene and environmental factors (smoking,drinking,sleeping condition and infection history )was studied by using Logistic regression and according to case-only study method. The smoking patients were defined as one cigarette a day lasting for one year or 18 bags per year, the drinking patients were defined as more than two times per week, the sleeping condition contains well, moderate and bad three categories, the infection history contains yes or no two categories.α=0.05.Results The male outpatients were 133 cases(80.6%),the female outpatients were 32 cases(19.4%),and the male to female ratio was 4.16:1.The average age of patients was 28.4±9.2 years, and the main occupations were farmers(40.2%) and workers(24.1%). Genetic susceptibility results showed that there may be no association between FCRL3 gene and the gentic susceptibility of AS(χ2=0.00,p=0.983;χ2=0.099,p=0.952), but there is an association between FCRL5 gene and the genetic susceptibility of AS(χ2=27.61,p=0.00;χ2=42.30,p=0.00). Multivariate Logistic regression showed that sex, disease history, education degree and drinking history were factors of BASFI index(p<0.05). Interaction analysis pointed out that there was certain interaction between drinking and FCRL3 gene[OR=2.56(1.12-5.88), p=0.026], and there was also significant interaction between FCRL3 gene[OR=0.15(0.09-0.24), p=0.00], FCRL5 gene[OR=0.14(0.09-0.22), p=0.00]and sleeping conditions.Conclusions Some susceptibility genes related to the pathogenesis of AS may occurred in FCRL gene cluster. The health education of ankylosing spondylitis in a crowd of young men who had a manual work, and to popularize the harm of drinking and the importance of adequate sleeping can show a lot of public health significance for the early prevention and control of ankylosing spondylitis.