Best Practice in Polymyalgia Rheumatica

Last week's articles on rheumatology topics in the major non-rheumatology journals.

Clinical Review: Polymyalgia rheumaticaBMJ, December 3, 2013

The British Society of Rheumatology has developed a three-step procedure to help primary care practitioners diagnose and treat classic polymyalgia rheumatica (PMR).  The society cautioned that “atypical” cases should be referred to a specialist, although there is no precise definition of atypical.

The protocol aimed at primary care physicians consists of clinical features and blood tests; excluding other conditions, and rapid and complete response to glucocorticoids.

The society pointed out that, in one study, 26% of patients diagnosed with PMR were misdiagnosed, and that the most common correct diagnosis was seronegative rheumatoid arthritis.

The diagnostic accuracy of ultrasound for PMR in general practice has not been validated and a study is ongoing.

The evidence base for treating PMR is weak, but ongoing research, including an observational cohort study, should shed more light on treatment options in the future. 

CD28 and ITK signals regulate autoreactive T cell traffickingNature Medicine, November 24, 2013

An experimental drug prevents cytotoxic T cells from leaving lymphoid organs and causing type 1 diabetes in mice.  It may prevent autoimmune disease while preserving antiviral defenses.

In mice missing the inhibitory receptor ctla-4, cytotoxic T cells infiltrate nonlymphoid tissues causing fatal autoimmunity, for example in type 1 diabetes.

But if those mice are also missing the CD28-activated kinase ITK, the cytotoxic T cells stay in the lymphoid organs, and they don’t develop type 1 diabetes.

Thee mice are healthy, and have normal antiviral immune responses.

ITK inhibitors also prevent pancreatic islet infiltration, and may prevent type 1 diabetes and other autoimmune diseases.