Rotating Intern Midwestern University College of Veterinary Medicine Glendale, Arizona, United States
Abstract:
Background: Treatment monitoring is subjective in dogs with pulmonary coccidioidomycosis. Biomarkers predictive of remission have not been explored. Hypothesis/
Objectives: (i) to characterize changes in serum C-reactive protein (CRP) and haptoglobin concentrations after starting antifungal therapy in dogs with pulmonary coccidioidomycosis, and (ii) evaluate the diagnostic performance of serum CRP and haptoglobin concentrations to detect remission. Animals: Thirty-one client-owned dogs with newly diagnosed pulmonary coccidioidomycosis.
Methods: Prospective cohort study. Serum was obtained at baseline and once every 3 months after antifungal administration until either remission or 12 months. Remission required the following criteria: (i) anti-Coccidioides spp. IgG titers ≤ 1:8, (ii) unremarkable or mild static thoracic radiographs, and (iii) an absence of related clinical signs. Serum CRP and haptoglobin were measured at a reference laboratory using ELISA assays.
Results: Twenty-seven (87%) dogs achieved remission in the 12-month study period. Median serum CRP and haptoglobin concentrations decreased from baseline (CRP: 56 mg/L; haptoglobin: 716 mg/dL) to the 3-month (CRP: 17 mg/L; haptoglobin: 410 mg/dL) evaluation (both P < .0001); subsequent decreases were not significant. Eighteen (58%) and 16 (56%) dogs had normal serum CRP and haptoglobin concentrations, respectively, at the 3-month visit. Serum CRP (sensitivity, 46%; specificity, 53%) and haptoglobin concentrations (sensitivity, 50%; specificity, 40%) at their optimal cutoffs were poor detectors of remission. Conclusions and clinical importance: Serum CRP and haptoglobin concentrations decrease in the first 3 months of antifungal treatment in dogs with pulmonary coccidioidomycosis but are not useful adjunctive tests to facilitate detection of remission.
