No abstract

Agency for Healthcare Research and Quality.

BackgroundArthritis pain is reported as one of the most common reasons for persons using medical herbal cannabis in North America. “Severe arthritis” is the condition justifying legal use of cannabis in over half of all authorizations in Canada, where cannabis remains a controlled substance. As champions for the care of persons with arthritis, rheumatologists must be knowledgeable of treatment modalities both traditional and non-traditional, used by their patients. As study of cannabinoid molecules in medicine is recent, we have examined the confidence in the knowledge of cannabinoids expressed by Canadian rheumatologists.MethodsThe confidence of rheumatologists in their knowledge of cannabinoid molecules and mechanisms relevant to rheumatology, and their ability to advise patients about cannabinoid treatments was recorded by an online questionnaire circulated via email to the entire Canadian Rheumatology Association membership.ResultsOver three quarters of the 128 respondents lacked confidence in their knowledge of cannabinoid molecules. While 45% of respondents believed there was no current role for cannabinoids in rheumatology patient care, only 25% supported any use of herbal cannabis. With 70% never having previously prescribed or recommended any cannabinoid treatment, uncertainty regarding good prescribing practices was prevalent. Concerns about risks of cannabis use were in line with the current literature.ConclusionsRheumatologists lacked confidence in their knowledge of cannabinoid molecules in general and in their competence to prescribe any cannabinoid for rheumatic complaints. In line with this uncertainty, there is reticence to prescribe cannabinoid preparations for rheumatology patients. Guidance is required to inform rheumatologists on the evidence regarding cannabinoids.

The antirheumatic effects of lymphocyte depletion in rheumatoid arthritis were confirmed in a randomized, double-blind trial. Six patients assigned to lymphapheresis demonstrated statistically significant decrements in counts of active joints, swollen joints, and a graded articular index compared to 6 patients similarly treated by a control procedure restricted to the removal of the volume of plasma incidentally lost during lymphapheresis. All patients treated by lymphapheresis developed lymphopenia, and in 4 the percentage of circulating T cells fell disproportionately by 26-58%. Serum IgM declined by 30% in lymphocyte depleted patients. Despite these changes in measures of cellular and humoral immunity, the mechanism of action of lymphapheresis remains obscure. The magnitude of change in synovitis did not correlate with the absolute numbers of mononuclear cells removed nor with the percent reduction in circulating lymphocytes, T cells, or IgM.Lymphocytes appear to be involved in both the initiation and perpetuation of the inflammatory events that underlie the manifestations of rheumatoid arthritis. They are the predominant cell type infiltrating rheumatoid synovium and nodules (1-3). Circulating lymphoFrom the Arthritis and Rheumatism Branch, National Institute of Arthritis, Metabolism and Digestive Disease, National Institutes of Health,