RT Journal Article
SR Electronic
T1 Procalcitonin Is a Specific Marker for Detecting Bacterial Infection in Patients with Rheumatoid Arthritis
JF The Journal of Rheumatology
JO J Rheumatol
FD The Journal of Rheumatology
SP jrheum.111601
DO 10.3899/jrheum.111601
A1 Hiroe Sato
A1 Naohito Tanabe
A1 Akira Murasawa
A1 Yasuhiro Otaki
A1 Takehito Sakai
A1 Toshiaki Sugaya
A1 Satoshi Ito
A1 Hiroshi Otani
A1 Asami Abe
A1 Hajime Ishikawa
A1 Kiyoshi Nakazono
A1 Takeshi Kuroda
A1 Masaaki Nakano
A1 Ichiei Narita
YR 2012
UL http://www.jrheum.org/content/early/2012/06/25/jrheum.111601.abstract
AB Objective Rheumatoid arthritis (RA) is a chronic inflammatory disease accompanied by many complications, and serious infections are associated with many of the advanced therapeutics used to treat it. We assessed serum procalcitonin (PCT) levels to distinguish bacterial infection from other complications in patients with RA. Methods One hundred eighteen patients experiencing an RA flare, noninfectious complication of RA or its treatment, nonbacterial infection, or bacterial infection were studied. Serum PCT concentrations were determined with a chemiluminescent enzyme immunoassay. Results All patients experiencing an RA flare showed negative PCT levels (≤ 0.1 ng/ml; n = 18). The PCT level was higher in the bacterial infection group (25.8% had levels ≥ 0.5 ng/ml) than in the other 3 groups (0.0–4.3% had levels ≥ 0.5 ng/ml) and the difference was significant among groups (p = 0.003). Conversely, no statistically significant difference was observed among the groups with C-reactive protein (CRP) concentration ≥ 0.3 mg/dl (p = 0.513), white blood cell (WBC) count > 8500/mm3 (p = 0.053), or erythrocyte sedimentation rate (ESR) > 15 mm/h (p = 0.328). The OR of high PCT level (≥ 0.5 ng/ml) for detection of bacterial infection was 19.13 (95% CI 2.44–149.78, p = 0.005). Specificity and positive likelihood ratio of PCT ≥ 0.5 ng/ml were highest (98.2% and 14.33, respectively) for detection of bacterial infection, although the sensitivity was low (25.8%). Conclusion Serum PCT level is a more specific marker for detection of bacterial infection than either CRP, ESR, or WBC count in patients with RA. High PCT levels (≥ 0.5 ng/ml) strongly suggest bacterial infection. However, PCT < 0.5 ng/ml, even if < 0.2 ng/ml, does not rule out bacterial infection and physicians should treat appropriately.