title: Do classic blood biomarkers of JSLE identify active lupus nephritis? Evidence from the UK JSLE Cohort Study.
abstract: Background Lupus nephritis (LN) affects up to 80% of juvenile-onset systemic lupus erythematosus (JSLE) patients. The value of commonly available biomarkers, such as anti-dsDNA antibodies, complement (C3/C4), ESR and full blood count parameters in the identification of active LN remains uncertain. Methods Participants from the UK JSLE Cohort Study, aged <16 years at diagnosis, were categorized as having active or inactive LN according to the renal domain of the British Isles Lupus Assessment Group score. Classic biomarkers: anti-dsDNA, C3, C4, ESR, CRP, haemoglobin, total white cells, neutrophils, lymphocytes, platelets and immunoglobulins were assessed for their ability to identify active LN using binary logistic regression modeling, with stepAIC function applied to select a final model. Receiver-operating curve analysis was used to assess diagnostic accuracy. Results A total of 370 patients were recruited; 191 (52%) had active LN and 179 (48%) had inactive LN. Binary logistic regression modeling demonstrated a combination of ESR, C3, white cell count, neutrophils, lymphocytes and IgG to be best for the identification of active LN (area under the curve 0.724). Conclusions At best, combining common classic blood biomarkers of lupus activity using multivariate analysis provides a 'fair' ability to identify active LN. Urine biomarkers were not included in these analyses. These results add to the concern that classic blood biomarkers are limited in monitoring discrete JSLE manifestations such as LN.
authors.affiliation: 1 Department of Women's and Children's Health, University of Liverpool, UK.
authors.forename: E M D
authors.initials: EMD
authors.lastname: Smith
authors.affiliation: 2 Department of Biostatistics, University of Liverpool, UK.
authors.forename: A L
authors.initials: AL
authors.lastname: Jorgensen
authors.affiliation: 1 Department of Women's and Children's Health, University of Liverpool, UK.|3 Department of Paediatric Rheumatology, Alder Hey Children's NHS Foundation Trust, UK.
authors.forename: M W
authors.initials: MW
authors.lastname: Beresford
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D001799:Blood Sedimentation; D003176:Complement C3 / Q000032:analysis*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D016015:Logistic Models; D008180:Lupus Erythematosus, Systemic / Q000097:blood* / Q000150:complications / Q000175:diagnosis; D008181:Lupus Nephritis / Q000097:blood* / Q000175:diagnosis / Q000209:etiology; D018655:Lymphocyte Count; D008214:Lymphocytes; D008297:Male; D015999:Multivariate Analysis; D009504:Neutrophils; D011237:Predictive Value of Tests; D012372:ROC Curve; D012307:Risk Factors; D006113:United Kingdom
chemical_list: D015415:Biomarkers; C038245:C3 protein, human; D003176:Complement C3; D007074:Immunoglobulin G
keywords: C3; C4; ESR; Lupus nephritis; anti-dsDNA; classic biomarkers; complement