Session Information
Date: Sunday, November 13, 2016
Title: Rheumatoid Arthritis – Clinical Aspects I: Pre-RA and Progression to Rheumatoid Arthritis
Session Type: ACR Concurrent Abstract Session
Session Time: 4:30PM-6:00PM
Background/Purpose: Early diagnosis of rheumatoid arthritis (RA) coupled with an effective treatment strategy is a key imperative in the effective management of disease. Anti-citrullinated peptide antibodies (ACPA) and antibodies against rheumatoid factor (RF) are two serological markers cited in the 2010 RA classification criteria that are commonly used in routine clinical practice. 14-3-3η protein is a mechanistic marker which seems to have a biologic role in the joint erosive process, that assists with the diagnosis of RA. The aim of this study, was to assess the clinical utility of 14-3-3η in the European EIRA (Epidemiological Investigation of Rheumatoid Arthritis) cohort.
Methods: 14-3-3η levels were measured in a total of 505 patient samples, 305 early RA patients samples and 200 control samples from the EIRA cohort using the 14-3-3η ELISA test (Augurex). Control samples included patients with various autoimmune conditions, infections, malignancies, osteoarthritis and healthy subjects. The specificity and sensitivity of 14-3-3η was assessed using the manufacturer’s suggested positivity cut-off of ≥ 0.19 ng/ml and at 2 and 4x of the diagnostic cut-off. The added value of 14-3-3η to CCP2 (Eurodiagnostica) in the diagnosis of RA was determined by examining the additional patients captured by 14-3-3η.
Results: As shown in the Table below, CCP2 had a sensitivity of 66.2% and a specificity of 96.5%. For 14-3-3η with a serum cutoff of ≥ 0.8 ng/ml the sensitivity was calculated to 47.2% and the specificity to 94.5%. Adding 14-3-3η resulted in a sensitivity of 74.1% compared to 66,2% for CCP2 alone. Depending upon the selected cut-off, up to 50.5% of the CCP-negative patients within the EIRA cohort could be identified by 14-3-3η.
|
|
CCP2 IgG (E/ml) |
14-3-3η (ng/ml) |
||
| Cut off |
≥ 25 E/ml |
≥ 0.19 |
≥ 0.40 |
≥ 0.80 |
| Sensitivity % |
66.2 |
68.2 |
59.3 |
47.2 |
| Additional No of Positives to CCP2 |
|
52 |
37 |
24 |
| Added Cohort Sensitivity % |
|
17.0 |
12.1 |
7.9 |
| Added sensitivity of CCP -ve patients % |
|
50.5 |
35.9 |
23.3 |
| Specificity |
96.5 |
83.0 |
90.5 |
94.5 |
| Loss of cohort specificity % |
|
16.0 |
9.5 |
4.5 |
Conclusion: Based on past publications the 14-3-3η protein is more frequently increased in established RA patients than in early RA patients. Nevertheless, even in our early RA cohort we could identify a considerable added value of increased sensitivity compared to CCP2. The 14-3-3η protein used in conjunction with CCP2 improves diagnostic sensitivity in the early diagnosis of RA.
To cite this abstract in AMA style:
Hansson M, Mathsson-Alm L, Marotta A, Swiniarski S. Evaluation of 14-3-3η As a Tool for Diagnosis of Early RA in a European Cohort [abstract]. Arthritis Rheumatol. 2016; 68 (suppl 10). https://acrabstracts.org/abstract/evaluation-of-14-3-3%ce%b7-as-a-tool-for-diagnosis-of-early-ra-in-a-european-cohort/. Accessed .« Back to 2016 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/evaluation-of-14-3-3%ce%b7-as-a-tool-for-diagnosis-of-early-ra-in-a-european-cohort/