Polymyalgia rheumatica with normal values of both erythrocyte sedimentation rate and C-reactive protein concentration at the time of diagnosis

The objective of this study was to develop EULAR/ACR classification criteria for polymyalgia rheumatica (PMR). Candidate criteria were evaluated in a 6-month prospective cohort study of 125 patients with new onset PMR and 169 non-PMR comparison subjects with conditions mimicking PMR. A scoring algorithm was developed based on morning stiffness >45 minutes (2 points), hip pain/limited range of motion (1 point), absence of RF and/or ACPA (2 points), and absence of peripheral joint pain (1 point). A score ≥4 had 68% sensitivity and 78% specificity for discriminating all comparison subjects from PMR. The specificity was higher (88%) for discriminating shoulder conditions from PMR and lower (65%) for discriminating RA from PMR. Adding ultrasound, a score ≥5 had increased sensitivity to 66% and specificity to 81%. According to these provisional classification criteria, patients ≥50 years old presenting with bilateral shoulder pain, not better explained by an alternative pathology, can be classified as having PMR in the presence of morning stiffness>45 minutes, elevated CRP and/or ESR and new hip pain. These criteria are not meant for diagnostic purposes.

To determine the frequency and clinical features of patients with polymyalgia rheumatica (PMR) and normal erythrocyte sedimentation rate (ESR) at diagnosis or during relapse/recurrence. To evaluate the usefulness of C-reactive protein (CRP) and ESR in the assessment of PMR activity. A prospective follow-up study on 177 consecutive patients meeting the criteria for PMR diagnosed over a 5-year period was conducted in two Italian secondary referral centers of rheumatology. At diagnosis and during follow-up, ESR (Westergren method) and CRP (nephelometry) were measured in all patients. Phenotypic analysis of lymphocyte subpopulations was performed on 78 PMR patients at diagnosis. A two-color technique using the association of specific monoclonal antibodies was applied. A control group consisting of 18 healthy adults older than 60 years was matched for age and sex with the PMR patients. Ten of 177 (6%) patients had normal ESR values at diagnosis (< or = 30 mm/h). Patients with normal ESR were predominantly men and had lower CRP levels; systemic signs and symptoms were more frequent in patients with higher ESR. The percentages of circulating CD8+ cells were similar in the two groups. CRP values at diagnosis were normal in only 2 of 177 (1%) patients. CRP values were elevated in 9 of 10 patients with normal ESR at diagnosis. Twenty-five episodes of relapse/recurrence with normal ESR occurred in 17 patients. CRP was high in 62% of these episodes. Results of univariate analysis indicated that the 10th percentile for ESR (40 mm/h) and the 70th percentile for CRP (7.8 mg/dL) values at diagnosis were the best cutoff points that discriminate between patients with and without relapse/recurrence. Cox proportional hazards modeling showed that ESR greater than 40 mm/h and CRP greater than 7.8 mg/dL at diagnosis were the two variables that independently increased the risk of relapse/recurrence. However, the relative risk related to ESR was twice than that related to CRP (4.9 vs 2.1). PMR with a normal ESR at diagnosis was infrequent in our study compared with previous studies. ESR was a superior predictor of relapse than CRP. However, CRP was a more sensitive indicator of current disease activity.

A prospective study of 287 patients with giant cell arteritis (GCA), including polymyalgia rheumatica (PMR) and temporal arteritis (TA), was conducted during 1987-1994. All patients were evaluated prior to the start of drug treatment. During the same period, 31 patients with GCA, of whom 12 cases had TA, were admitted to other departments in the hospital. At onset of disease, all patients were > or = 50 yr of age. Peripheral arthritis was found in 24.4% of patients with PMR, while none of the patients with TA exhibited such manifestations. Clinical features at onset of disease differed from those appearing at presentation to the hospital. Thus, the gradual development of a full-blown clinical picture may be responsible for the delay in diagnosis of GCA. The majority of cases (80%) presented with "pure' PMR without clinical signs or symptoms of concomitant TA. In a random sample of 68 patients with "pure' PMR, histological examinations of biopsy specimens of the temporal artery revealed inflammatory changes in three patients only (4.4%). Consequently, arterial biopsy in patients with clinical features of PMR only, appears to be unnecessary. Among patients with TA referred to the department of internal medicine, general malaise, loss of weight and sustained fever were prominent manifestations. Such features may thus necessitate a diagnostic arterial biopsy even in the absence of clinical arteritis or myalgia. Both ESR and CRP were within normal levels in 1.2% of the cases. Further clinical and laboratory examinations performed at diagnosis of GCA disclosed only one case of malignancy. Routine chest X-rays did not reveal unexpected pathological findings. Permanent and complete blindness due to arteritis was observed in one patient only. No association between GCA and thyroid dysfunction was detected.