ACTH as a treatment for acute crystal-induced arthritis: update on clinical evidence and mechanisms of action.

BACKGROUND

ACTH, a member of the melanocortin group of proteins, has long been used in the treatment of gout and is considered as an alternative therapeutic option, especially in difficult-to-treat patients.

METHODS

We performed a systematic electronic search (Medline and ScienceDirect) using the keywords gout, treatment, ACTH, adrenocorticotropic hormone, and pseudogout. We identified 5 studies assessing the efficacy of ACTH in acute crystal-induced arthritis.

RESULTS

In the studies for acute gout, a total of 266 patients have been treated with ACTH; treatment was highly efficacious with a response rate of 77.9-100%. Only few side effects, such as hyperglycemia, hypokalemia, and edema, were reported, all of which were mild. The available evidence for acute CPP crystal arthritis is limited. A total of 19 patients have been assessed in retrospective studies; the response rate was 90-100%, whereas no significant side effects were recorded. The mechanism of action of ACTH in acute crystal-induced arthritis is not entirely known but seems to extend beyond stimulation of steroid release from the adrenal glands; ACTH is able to stimulate melanocortin receptors on macrophages and downregulate gouty inflammation.

CONCLUSIONS

Data suggests that ACTH is effective in acute crystal-induced arthritis and may be a first-line therapy in patients with multiple medical problems. We propose that further evaluation of ACTH should be performed, with a large-scale, randomized controlled study focusing on safety issues in patients with multiple comorbidities.