TAKAYASU ARTERITIS (TAK): DISEASE CHARACTERISTICS
OUTCOMES IN A COHORT OF 75 PATIENTS
Background
Takayasu arteritis (TAK) is a rare chronic inflammatory disease of unknown cause that has a predilection for large arteries. It most often affects the aorta and its primary branches. Although once thought to be a disorder that primarily affected young females from the Far East, TAK has been identified in both genders and in many ethnic and racial groups worldwide. The incidence of TAK has been reported in 2.6 cases/million population/year in Olmstead County, Minn., and in 1.2 cases/million population/year in Sweden. Few medical centers in the United States have amassed an adequate experience with TAK to enable comparisons of disease features and outcomes with cohorts reported from Asia and Mexico. Since 1992, Cleveland Clinic’s Center for
Vasculitis Care and Research has provided a standardized approach to diagnosis, follow-up and treatment of patients with TAK, including obligatory imaging of the entire aorta and its branch vessels at least every six to 12 months. This approach was derived from that of the National Institutes of Health (NIH) longitudinal cohort. The NIH study suggests that TAK is a chronic, relapsing illness, associated with considerable morbidity; these outcomes are less optimistic than had been reported from cohorts in the Far East.
More than 150 such patients are followed by the center’s staff and referring doctors. Seventy-five patients receive care principally from the center’s staff. We evaluated clinical, laboratory and radiographic data from 76 patients with TAK who received care from one physician within our Center for Vasculitis Care and Research.
Methods Response to treatment was considered successful if signs or symptoms of disease activity were absent, laboratory studies were normal, and new vascular abnormalities were not identified on sequential imaging studies over an interval of at least six months. Remission was judged to be present if these guidelines were met and the patient required <>
Results
Ninety-one percent of TAK patients were female; 88% were Caucasian. Mean age was 26 years. The most common signs and symptoms of disease included absent pulse (57%), BP asymmetry (55%), headache (53%), limb claudication (52%), fever (35%), hypertension (28%) and arthralgias with myalgias (13%). The most common vessels involved were subclavian (65%), carotid (44%), mesenteric (32%), renal (25%), and femoral (28%) arteries. Sixteen percent of patients had a monophasic course, requiring no sustained therapy. In the 30 patients who received extended follow-up care at our center, relapses were frequent, occurring an average 2.9 times/ patient over a median period of two years. Nineteen of 30 patients required vascular interventions. Eight of 30 became disabled. There were two deaths in this group.
Clinical Symptoms Compared to NIH Cohort
Distribution of Arterial Lesions Cleveland Clinic Cohort
Conclusions
Our experience represents the largest cohort of TAK patients in the United States. The clinical characteristics of our patients are similar to those published from the NIH cohort in regard to signs, symptoms and lesion distribution. Although most patients achieved remission, 70% required agents other than prednisone for maintenance therapy. Of all patients who received therapy, 30% required more than two immunosuppressive agents in addition to corticosteroids. The number of patients who achieved long-term remission is low. Of the group followed at our center for at least two years (median 3.75 years), treatment resulted in disease control in 89% of patients, but only 8% achieved steroid-free remission. Despite continued advances in medical and surgical interventions, significant morbidity from TAK and its therapy remains high. Data from our recently published open-label study suggest that anti-TNF agents may improve outcomes in TAK. A randomized-controlled trial, however, will be necessary to determine whether such therapy is appropriate for patients with this disease.
[KM McKinnon, TM Clark, GS Hoffman]
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