Prevalence And Significance Of Serum 14-3-3 Eta In Juvenile Idiopathic Arthritis

Background Prompt diagnosis of juvenile idiopathic arthritis (JIA) is important to avoid long term complications. Elevated serum 14-3-3 eta levels improve the diagnostic sensitivity of rheumatoid factor (RF) and cyclic citrullinated peptide (CCP) antibody in adult rheumatoid arthritis (RA), and have been associated with more severe phenotype. We investigated the prevalence and clinical significance of serum 14-3-3 eta in different types of JIA. Methods JIA patients (n = 151) followed by the Pediatric Rheumatology Core at Children's Hospital of Los Angeles were categorized into 5 groups: polyarticular JIA RF+ (PJIA RF+; n = 39), PJIA RF- (n = 39), psoriatic arthritis (PsA; n = 19), enthesitis-related arthritis (ERA; n = 18), and oligoarticular JIA (OJIA [control group]; n = 36). RF, CCP antibody, and 14-3-3 eta were measured for all patients. 14-3-3 eta serum levels > 0.2 ng/mL were considered positive. Disease activity was assessed by the Juvenile Arthritis Disease Activity Score-71 (JADAS-71). Results Elevated 14-3-3 eta levels were detected in 34/151 (23%) patients, and across all groups tested. Most patients with 14-3-3 eta had titers >= 4 times above the cutoff value. The majority (22, 65%) of 14-3-3 eta-positive patients were also positive for RF or CCP antibodies, 16 (47%) were positive for all 3, and 12 (35%) were single-positive for 14-3-3 eta. The highest prevalence of 14-3-3 eta was in PJIA RF+ patients (49%), followed by OJIA (22%). Positivity for 14-3-3 eta was not significantly associated with disease activity or age at diagnosis. Conclusion Serum 14-3-3 eta can be detected in all forms of JIA tested but appears to be most common in PJIA RF+. 14-3-3 eta does not appear to correlate with disease activity in JIA.