The 2020 Pediatric Rheumatology Symposium, originally scheduled for April 29 – May 2, was postponed due to COVID-19; therefore, abstracts were not presented as scheduled.
Date: Thursday, April 30, 2020
Session Title: Poster Breakout 1 – Advances in Diagnosis & Classification
Session Type: Poster Breakout Session
Session Time: 5:10PM-5:40PM
Background/Purpose: Treat-to-target strategies are established for the therapeutic approach to patients suffering from juvenile idiopathic arthritis (JIA). Another proposed therapeutic concept in pediatric rheumatology involves the “window of opportunity” for the treatment of systemic JIA (sJIA), which has been supported by the success of early treatment including biologics. The implementation of these strategies and concepts relies on i) timely diagnosis making to initiate and ii) tight monitoring of disease activity to adapt therapeutic intervention. The use of biomarkers for these purposes offers added value. Here, we report on the validation of a serum calprotectin (sCAL, MRP8/14) point-of-care rapid test based on lateral flow immunoassay (LFIA) technology.
Methods: The sandwich-type Quantum Blue®sCAL LFIA (BÜHLMANN, Switzerland) was applied to test samples from patients with JIA. We used 172 serum samples from patients with non-systemic JIA, included into the German inception cohort of newly diagnosed patients with JIA (ICON-JIA), to analyze the correlation of the LFIA rapid test with an established sCAL (MRP8/14) ELISA (BÜHLMANN, Switzerland). In additional 5 JIA patients, the direct application of capillary blood was tested to even maximize the concept as a rapid point-of-care test. Moreover, the sCAL LFIA was tested with serum samples from 377 patients presenting with fever and inflammation in whom sJIA was suspected.
Results: The sCAL LFIA values in serum correlated closely with the sCAL ELISA values both in non-systemic JIA (r=0.92, p< 0.0001) and sJIA (r=0.95, p< 0.0001). The sCAL LFIA levels obtained from capillary blood correlated well with sCAL ELISA levels obtained in serum samples (r=0.98, p< 0.01). The values correlated with disease activity and other markers of inflammation such as CRP. In the patients with fever and inflammation, the levels in sJIA were significantly higher compared to all other febrile diseases. sJIA could be correctly confirmed with a sensitivity of 84% and a specificity of 80% (area under curve was 0.859).
Conclusion: The BÜHLMANN Quantum Blue®sCAL LFIA rapid test allows fast and easy detection of serum Calprotectin (MRP8/14) concentrations in blood within 15 minutes in clinical real-life settings. The assay shows an excellent correlation to a standardized serum ELISA reference method. MRP8/14 serum analyses could be validated as a helpful tool supporting the diagnosis of sJIA in patients presenting with fever of unknown origin. The rapid diagnostic point-of-care test can also be used for the assessment of inflammatory activity, thus enabling tight monitoring of responses to therapy and neccesary treatment adaptations in a treat-to-target approach.
To cite this abstract in AMA style:Foell D, Park C, Ziegler L, Holziner D, Minden K, Cotti R, Weber J. Successful Validation of a Rapid Point-of-care Test for Serum Calprotectin (MRP8/14) as Biomarker in Juvenile Idiopathic Arthritis [abstract]. Arthritis Rheumatol. 2020; 72 (suppl 4). https://acrabstracts.org/abstract/successful-validation-of-a-rapid-point-of-care-test-for-serum-calprotectin-mrp8-14-as-biomarker-in-juvenile-idiopathic-arthritis/. Accessed October 26, 2021.
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/successful-validation-of-a-rapid-point-of-care-test-for-serum-calprotectin-mrp8-14-as-biomarker-in-juvenile-idiopathic-arthritis/