Procalcitonin Differs in Children With Infection and Children With Disease Flares in Juvenile Idiopathic Arthritis.

BACKGROUND/OBJECTIVE: Patients with juvenile idiopathic arthritis (JIA) often present with signs and symptoms suggestive of serious bacterial infection (SBI). Procalcitonin (PCT) is a biomarker that is elevated in SBI. We conducted a comparative cohort study to test the hypothesis that PCT levels will differ between active JIA, quiescent JIA, and bacteremic patients and healthy controls. METHODS: From October 2016 to May2018, consecutive children 6 months to 18 years of age with (a) active untreated JIA, (b) quiescent JIA, and (c) healthy elective presurgical candidates were recruited from clinics at a musculoskeletal specialty hospital. Juvenile idiopathic arthritis was defined according to the International League of Associations for Rheumatology criteria. Clinical data and serum samples meeting the same criteria were included from a prior study. Consecutive bacteremic patients were identified over the same period. Procalcitonin and other common measures of inflammation were measured. Descriptive statistics and univariate logistic analyses were performed. RESULTS: Ninety-two study subjects were recruited. Erythrocyte sedimentation rate, C-reactive protein (CRP), and PCT levels were all elevated in bacteremic patients in comparison to the other groups. Erythrocyte sedimentation rate and CRP both had wide ranges that overlapped between groups; however, the PCT concentration was 0.15 µg/mL or greater in 1 of 59 patients with JIA, whereas it was 0.15 µg/mL or less in only 1 bacteremic patient. CONCLUSIONS: Our study indicates that serum erythrocyte sedimentation rate, CRP, and PCT levels are all biomarkers that can be used to distinguish SBI versus active JIA at presentation. However, PCT is the most accurate, with the least overlap between patients with infection and noninfectious inflammatory arthritis. This finding can help clinicians direct therapy.

PROMIS Computer Adaptive Tests and Their Correlation With Disease Activity in Juvenile Idiopathic Arthritis.

BACKGROUND/OBJECTIVE: The importance of patient-reported outcomes, like the Patient-Reported Outcomes Measurement Information System (PROMIS) measures, is increasingly recognized both in clinical care and in research. While "short forms" have been studied in juvenile idiopathic arthritis (JIA), study of PROMIS computer adaptive tests (CATs) in JIA is limited. This cross-sectional study evaluates whether PROMIS CATs correlate with disease activity in patients with JIA. METHODS: A convenience sample of patients with JIA (N = 44) was recruited from a single center. Patients and parents completed pediatric and parent proxy PROMIS CATs. Disease activity was evaluated using the Juvenile Arthritis Disease Activity Score in 71 joints (JADAS-71) and the Childhood Health Assessment Questionnaire (CHAQ). Correlation of the CAT T scores with disease activity was assessed using Spearman correlation coefficients. RESULTS: Forty-four of 80 eligible subjects (29 patients and 15 parents) completed all or some PROMIS CATs. Pain interference and mobility CATs correlated moderately with JADAS-71. Nearly all correlations with the JADAS-71 were weakened when the patient global was removed. Pain interference, mobility, and fatigue were strongly correlated with the CHAQ. Among parent proxy CATs, only mobility and depressive symptoms correlated strongly with the CHAQ. CONCLUSIONS: Only pain interference and mobility PROMIS CATs showed strong correlation with standard disease activity measures in JIA, and nearly all correlations were weakened when the patient global was removed. Correlations of the CATs with the CHAQ were stronger than correlations with the JADAS-71, indicating that although the CHAQ is no longer routinely used it may be a better measure of health-related quality of life in routine clinical care.