STUDY: Chinese remedy Tripterygium wilfordii Hook F (TWHF) extract offered benefit to patients with refractory rheumatoid arthritis.

JOURNAL: Arthritis Rheum. 2002;46:1735-1743

AUTHORS: Xuelian Tao, MD

ABSTRACT: The Chinese remedy Tripterygium wilfordii Hook F (TWHF) extract was well tolerated and offered benefit to patients with refractory rheumatoid arthritis, according to the results of a double-blind, placebo-controlled trial reported in the July issue of Arthritis & Rheumatism.

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COMMENTARY: Extracts of TWHF have been widely used in China to treat a broad spectrum of autoimmune and inflammatory diseases. Results from most of the clinical trials of TWHF have claimed significant therapeutic benefit, although nearly all of the trials were uncontrolled, as mandated by Chinese custom.

In this trial, 35 patients with refractory, longstanding rheumatoid arthritis were randomized to treatment with placebo, low-dose extract (180 mg/day), or high-dose extract (360 mg/day) for 20 weeks, followed by an open-label extension period. Of patients who completed at least four weeks of treatment, eight of 10 in the high-dose group, four of 10 in the low-dose group, and none of 12 in the placebo group met criteria for clinical response, defined as 20% improvement in disease activity according to American College of Rheumatology criteria.

Of patients enrolled in the open-label extension, five of seven receiving high-dose extract, four of seven receiving low-dose extract, and two of four receiving placebo met criteria for clinical response.

Of 35 patients initially enrolled in the trial, 21 completed the 20-week study; one patient from each group withdrew because of adverse effects. The most common adverse effect was diarrhea. No patients withdrew because of adverse events during the open-label extension.

Despite study limitations and the need for larger trials, the authors noted that TWHF extract at 360 mg/day appears to be safe in rheumatoid arthritis patients. The symptoms and signs of inflammation and the physical functioning of most of the patients in the trial improved.