Abstract
The aim of this study was to explore the correlation of salazosulfamide efficacy on ankylosing spondylitis and N-acetyltransferase 1 (NAT1) gene polymorphism. Thirty-two patients with ankylosing spondylitis were recruited in the experimental group and 36 normal individuals were recruited to the control group. The experimental group received 8.0 mg of salazosulfamide (MTX) per week and the control group received isodose of normal saline. Twenty-six patients in the experimental group responded to the salazosulfamide treatment and 6 did not show response. Morning stiffness time of patients in the experimental group who responded to salazosulfamide was significantly lower than that of patients with no reaction to salazosulfamide, and similar to patients in the control group. The average tender joint count of patients in the experimental group that responded to salazosulfamide was lower than in patients with no response to treatment, and similar to patients in the control group. NAT1 gene sequencing determined that the patients sensitive to salazosulfamide treatment manifested as AA/AG at 263 locus, whereas patients not sensitive to salazosulfamide were GG. NAT1 expression was comparable between the different genotypes at the mRNA level. However, there was a significant difference of NAT1 protein between groups. Overall, salazosulfamide demonstrates curative activity for ankylosing spondylitis and we believe that NAT1 AA/GG genotype at 263 locus can promote salazosulfamide effectiveness on ankylosing spondylitis.