The Severity of Takayasu Arteritis Is Associated with the HLA-B52 Allele in Japanese Patients

Takayasu arteritis (TA) is a type of vasculitis that affects the large elastic arteries, specifically the aorta and its main branches. It has been reported that TA occurred most frequently in Nagasaki Prefecture, the western area in Japan. We retrospectively collected the information of 34 patients with TA, diagnosed using the American College of Rheumatology 1990 criteria for the classification of TA, from the medical records of Nagasaki University Hospital from 2003 to 2015, and we investigated the clinical characteristics of these TA patients. Among the 35 patients, 25 patients were examined for the existence of the HLA-B52 allele that has been reported to influence TA susceptibility. Seventeen patients (68.0%) of the 25 patients were HLA-B52-allele-positive, which was defined as the state of having at least one HLA-B52 allele. There was a significant difference in the rate of smokers: HLA-B52-allele-positive: six patients (35.3%) vs. HLA-B52-allele-negative: 0 (0.0%). The C-reactive protein level in the HLA-B52-positive patients (9.0 +/- 6.4 mg/dL) was significantly higher than that in the HLA-B52-negative patients (3.2 +/- 3.9 mg/dL). All HLA-B52-allele-positive patients were found to be active according to Kerr's criteria. The HLA-B52-positive patients' initial prednisolone dosage (37.7 +/- 8.6 mg/day) was significantly higher than that of the HLA-B52-allele-negative patients (23.1 +/- 13.1 mg/day). Thus, the HLA-B52 allele is associated with the disease activity and the steroid requirements of TA patients. Furthermore, our present findings have revealed for the first time that the HLA-B52 allele and smoking might be associated with the onset of TA.