Objective: To assess clinical and laboratory features that may be useful in differentiating isolated polymyalgia rheumatica (PMR) from PMR associated with biopsy proven giant cell arteritis (GCA); and in differentiating biopsy proven GCA associated with PMR from GCA without manifestations of PMR.
Methods: Clinical records of patients with PMR and biopsy proven GCA diagnosed at Hospital Xeral, Lugo, Spain from January 1987 through May 1997 were reviewed. Patients with a positive temporal artery biopsy were categorized into 2 different subgroups according to the presence or absence of associated PMR. The patients with biopsy proven GCA associated with PMR were compared with a group of patients with isolated PMR (not associated with GCA).
Results: From a total of 108 biopsy proven patients with GCA, 45 had associated PMR. Apart from a predominance of women and a longer delay to diagnosis, patients with PMR associated with GCA did not differ from the patients with GCA without PMR manifestations. In comparing patients with isolated PMR (n=117) with patients with PMR associated with GCA, we observed that PMR associated with GCA was a more severe disease, with significant abnormality in most laboratory variables, including constitutional syndrome, higher elevation of erythrocyte sedimentation rate and platelet counts, and lower values of hemoglobin.
Conclusion: In both isolated PMR and PMR associated with GCA we observed a predominance of women. While there are no differences in the type of polymyalgia symptoms in patients with isolated PMR versus PMR associated with GCA, severe abnormalities associated with the inflammatory response in PMR may have prognostic value for more severe disease, which may be linked to the presence of GCA.