We sought to identify clinical features at diagnosis that can distinguish isolated polymyalgia rheumatica (PMR) without giant cell arteritis (GCA) from PMR with GCA, and clinical features at diagnosis of isolated PMR that can predict subsequent relapse and corticosteroid discontinuation.
A retrospective study of 115 patients with isolated PMR and 29 patients with GCA was performed. A comparison between isolated PMR patients, GCA patients (with or without PMR), and PMR with GCA patients was performed. Predictors of relapse and corticosteroid discontinuation were identified using a logistic regression in the patients with isolated PMR.
Matrix metalloproteinase-3 (MMP-3) level was significantly different among the patient groups. MMP-3: 230.5 ± 201.5 ng/mL in isolated PMR, 80.5 ± 47.5 ng/mL in GCA (p < 0.01), and 96.8 ± 54.8 ng/mL in PMR with GCA (p = 0.03). In the patients with isolated PMR, female gender (odds ratio [OR], 2.73; 95% confidence interval [CI], 1.16-6.41; p < 0.05) and creatinine (Cr) < 50 μmol/L (OR, 2.48; 95% CI, 1.02-5.99; p < 0.05) were significant prognostic factors that predicted relapse.
A low level of MMP-3 is an excellent positive predictor for PMR with GCA. Among patients with isolated PMR, female gender and Cr < 50 μmol/L were significant prognostic factors that predicted relapse.