A diagnostic algorithm to evaluate elevated C-reactive protein levels in juvenile systemic lupus erythematosus

Area of Science:

• Pediatric Rheumatology
• Immunology
• Clinical Diagnostics

Background:

• Elevated C-reactive protein (CRP) in juvenile systemic lupus erythematosus (JSLE) lacks clear correlation with disease activity.
• Accurate identification of causes for elevated CRP is crucial for appropriate management in JSLE patients.

Purpose of the Study:

• To develop and validate an algorithm for evaluating elevated CRP episodes in juvenile SLE patients.
• To differentiate between infection, autoimmune flares, and other causes of elevated CRP in JSLE.

Main Methods:

• Retrospective analysis of 190 JSLE patients with 174 episodes of elevated CRP.
• Development of a diagnostic algorithm prioritizing potential etiologies.
• Validation of the algorithm in a primary and an external JSLE cohort.

Main Results:

• Infections were the most common cause (79.9%) of elevated CRP, followed by arthritis (8.6%) and macrophage activation syndrome (MAS) (5.2%).
• MAS was more frequent in patients with higher SLE disease activity index (SLEDAI) scores.
• The developed algorithm achieved 99.4% accuracy in the primary cohort and 98.5% in the external cohort.

Conclusions:

• The algorithm effectively assists physicians in evaluating elevated CRP in JSLE patients.
• Further validation in larger cohorts may enhance the algorithm's clinical utility.