Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


Normal Sedimentation Rate and C-Reactive Protein at Diagnosis in Biopsy-Proven Giant Cell Arteritis.

A. Kermani,  Tanaz, S. Crowson,  Cynthia, R. Ytterberg,  Steven, G. Hunder,  Gene, J. Warrington,  Kenneth

Purpose:

1) To determine the frequency of normal erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) at diagnosis in biopsy-proven giant cell arteritis (GCA) and 2) to evaluate clinical factors associated with discordant or normal ESR/CRP.

Methods:

In this retrospective cross-sectional study, medical records of all patients with biopsy-proven GCA evaluated between January 1, 2000 and December 31, 2008 were reviewed. Only subjects with ESR and CRP available at the time of diagnosis were included. Clinical information was abstracted. Subjects with both ESR and CRP normal and those with discordant ESR/CRP were identified. We used our laboratory cut-off values for elevated ESR (>22 mm/hour for men and >29 mm/hour for women) and CRP (>8 mg/L). Fisher's exact test was used to compare categorical variables between patients with discordant results to those with concordant ESR/CRP, and GCA patients with normal ESR/CRP to those with elevated ESR/CRP. Rank sum tests were used to compare continuous variables between the above two groups.

Results:

Two-hundred and forty patients were diagnosed with biopsy-proven GCA at a single institution during the study period. Of these, 160 subjects (78%) had ESR and CRP available prior to GCA diagnosis. The final study population included 119 women (74.4%) and 41 men (25.6%); mean age at diagnosis 74.3 years (±7.59). Nine patients (5.6%) had discordant ESR and CRP of whom 7 had elevated CRP but normal ESR. Mean age at diagnosis of GCA, mean duration of symptoms, clinical symptoms and laboratory findings at GCA diagnosis were similar in patients with discordant ESR/CRP compared to patients with concordant results (p>0.05).

Both ESR and CRP were normal in 18 patients (11.3%), 11 of whom were on prednisone and were excluded from the analysis. However, 7 patients (4%) had normal ESR and CRP at diagnosis in the absence of prednisone use. Table 1 compares the clinical manifestations and laboratory findings of these 7 patients to those with elevated ESR or CRP. A greater proportion of patients with normal ESR and CRP had polymyalgia rheumatica (PMR) symptoms compared to patients with elevated ESR or CRP (p=0.02). Furthermore, fewer patients with normal ESR and CRP had anemia (p<0.001) and there was a trend toward less thrombocytosis (p=0.09) compared to subjects with elevated ESR or CRP.

Table 1. Clinical manifestations of GCA patients with normal ESR and CRP to those with elevated ESR and/or CRP

Clinical VariableESR, CRP elevated, No (%) N=126ESR and CRP normal, No (%) N=7p-value
Female gender92 (73)6 (85.7)0.68
Mean age at diagnosis, years74.3 (±7.88)70 (±5.87)0.12
Median duration symptoms, days531130.32
Mean duration from laboratory testing to biopsy, days6.1 (±8.34)8.7 (±9.07)0.52
New headache79 (62.7)4 (57.1)1.00
Jaw claudication61 (48.4)2 (28.6)0.45
Scalp tenderness43 (34.1)2 (28.6)1.00
Permanent vision loss11 (8.7)1 (14.3)0.49
Fever31 (24.6)0 (0)0.20
Anorexia16 (12.7)0 (0)0.60
Weight loss42 (33.3)1 (14.3)0.43
Polymyalgis rheumatica33 (26.2)5 (71.4)0.02
NSAID use61 (49.6)2 (28.6)0.44
Anemia89 (70.6%)0 (0)<0.001
Thrombocytosis43 (36.4)0 (0)0.09

Conclusions:

CRP is considered a more sensitive marker in GCA. This is the largest, single center study to date evaluating the prevalence of normal CRP in biopsy-proven GCA. While ESR and CRP were concordantly elevated in most patients, discordant results were noted in 5.6%. More significantly, 4% of patients in this study had both normal ESR and CRP at diagnosis. They were more likely to present with PMR symptoms. Absence of a systemic inflammatory response does not exclude GCA and biopsy should be pursued in patients with high clinical suspicion of GCA, especially if PMR symptoms are present.

To cite this abstract, please use the following information:
A. Kermani, Tanaz, S. Crowson, Cynthia, R. Ytterberg, Steven, G. Hunder, Gene, J. Warrington, Kenneth; Normal Sedimentation Rate and C-Reactive Protein at Diagnosis in Biopsy-Proven Giant Cell Arteritis. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :1304
DOI: 10.1002/art.29070

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