RT Journal Article
SR Electronic
T1 Predicting Macrophage Activation Syndrome in Childhood-onset Systemic Lupus Erythematosus Patients at Diagnosis
JF The Journal of Rheumatology
JO J Rheumatol
FD The Journal of Rheumatology
SP 1450
OP 1457
DO 10.3899/jrheum.200292
VO 48
IS 9
A1 Maya Gerstein
A1 R. Ezequiel Borgia
A1 Daniela Dominguez
A1 Brian M. Feldman
A1 Fangming Liao
A1 Deborah M. Levy
A1 Lawrence Ng
A1 Mohamed Abdelhaleem
A1 Earl D. Silverman
A1 Linda T. Hiraki
YR 2021
UL http://www.jrheum.org/content/48/9/1450.abstract
AB Objective Macrophage activation syndrome (MAS), a life-threatening inflammatory complication, is increasingly recognized in childhood-onset systemic lupus erythematosus (cSLE). It can be a challenge to differentiate active cSLE from MAS. We generated decision rules for discriminating MAS from active cSLE in newly diagnosed patients.Methods We conducted a retrospective cohort study of consecutive, newly diagnosed, active cSLE patients with fever, requiring hospital admission to The Hospital for Sick Children from January 2003 to December 2007 (cohort 1) and January 2008 to December 2013 (cohort 2). All patients met ≥ 4 American College of Rheumatology or Systemic Lupus International Collaborating Clinics criteria, and were steroid-naïve and infection-free. MAS was diagnosed based on expert opinion. Recursive partitioning was applied to each cohort to derive a decision rule based on clinical and laboratory features, distinguishing MAS from non-MAS cSLE. Each decision rule was applied to the alternate, independent cohort. Sensitivity and specificity of these decision rules were compared to existing criteria.Results Cohort 1 (n = 34) and cohort 2 (n = 41) each had 10 patients with MAS. Recursive partitioning in cohort 1 identified ferritin ≥ 699 μg/L as the sole best discriminator between MAS and non-MAS patients (R2 = 0.48), and in cohort 2, ferritin ≥ 1107 μg/L was the best discriminator for MAS, followed by lymphocytes < 0.72 × 103/mm3 (R2 = 0.52). Cross-validation of our decision rules maintained 90–100% sensitivity and 65–85% specificity.Conclusion Our decision rule demonstrated improved performance compared to preliminary guidelines for MAS in cSLE from the Lupus Working Group of the Paediatric Rheumatology European Society and familial hemophagocytic lymphohistiocytosis diagnostic criteria. Validation in independent cohorts is required.