Differences in Acute Phase Reactants between Gout and Pseudogout

Objectives: To define clinical differences in the acute phase response and serum acute phase reactants between gout, pseudogout and crystal-induced arthritis in the presence of non-articular infections (CAI). Patients and Methods: Eleven patients with definite gout, 12 patients with pseudogout and 5 patients with CIA were included in the study. Results: The erythrocyte sedimentation rate (ESR) was significantly different between gout (68.2 ± 49.9 mm/Hr) and CIA (113.8 ± 37.2 mm/Hr) but not between gout and pseudogout (83.9 ± 45.6 mm/Hr) or between pseudogout and CIA. The C-reactive protein (CRP) was significantly increased between gout (10.1 ± 7.9 mg/dL) and pseudogout (18.9 ± 9.8 mg/dL), gout and CIA (36.5 ± 12.4 mg/dL) as well as between pseudogout and CIA. The peripheral white cell count was significantly different between gout (9.27 ± 3.7 k/μL) and CIA (16.5 ± 6.8 k/μL), and between pseudogout (8.9 ± 3.2 k/μL) and CIA. Conclusions: Measurement of ESR and CRP are helpful in crystal-induced arthritis. The CRP has more discriminating utility than the ESR in distinguishing between gout, pseudogout and CIA. Peripheral wbc is most useful for differentiating crystal-induced arthritis from CIA.