Laboratory investigations useful in the evaluation of polymyalgia rheumatica (pmr) and giant cell arteritis (GCA)

B. Hazleman

FRCP, Rheumatology Department, Unit E6, Addenbrooke's Hospital, Cambridge, UK.

ABSTRACT
The most useful investigation in supporting the clinical diagnosis of PMR/GCA is elevation of the erythrocyte sedimentation rate (ESR) or viscosity. Acute phase proteins, particularly CRP, are also elevated but in most cases are not more helpful than the ESR in either diagnosis or follow-up. The definitive investigation is the demonstration of giant cell arteritis histologically, usually from temporal artery biopsy. Elevation of alkaline phosphatase of liver origin is seen in one-third to one-half of patients and may lead to delay in diagnosis.
Measurements of a1-antichymotrypsin and IL-1b may be helpful in diagnosis and management but more studies are required.

Key words
Polymyalgia rheumatica, giant cell arteritis, laboratory tests.

Please address correspondence and reprint requests to: Brian Hazleman, MA, MD, FRCP, Rheumatology Department, Box 194, Unit E6, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 2QQ, UK.
E-mail: brian.hazleman@ msexc.addenbrookes.anglox.uk

Clin Exp Rheumatol 2000; 18 (Suppl. 20): S29-S31.
© Copyright Clinical and Experimental Rheumatology 2000.