title: Measuring eosinophiluria, urinary eosinophil cationic protein and urinary interleukin-5 in patients with Lupus Nephritis.
abstract: BACKGROUND
  Urine is increasingly becoming an attractive biological fluid in clinical practice due to being an easily obtained, non-invasive sampling method, containing proteins and peptides. The aim of this study was to investigate eosinophiluria, urinary eosinophil cationic protein (uECP) and urinary IL-5 (uIL-5) in patients with Lupus Nephritis.
  
  
  METHODS
  Seventy-four patients with SLE-20 with clinical and laboratory evidence of lupus nephritis (LN group) and 54 without evidence of renal involvement (non-LN group)-were analyzed regarding eosinophiluria, uECP and uIL-5. Eosinophiluria was observed by Hansel's stain, ECP by fluoroenzymeimmunoassay and uIL-5 by quantitative sandwich enzyme immunoassay. Both uECP and urinary IL-5 (uIL-5) were corrected by urinary creatinine. Eosinophiluria and uECP were compared with glomerular erythrocyturia, protein/creatinine ratio (Pr/Cr ratio), serum creatinine, estimated glomerular filtration rate (eGFR), anti-double-stranded DNA (anti-dsDNA), serum levels of complement (C3 and C4), uIL-5/Cr ratio, and SLE disease activity index.
  
  
  RESULTS
  Patients of the LN group had higher eosinophiluria, uECP, uECP/Cr ratio levels, and uIL-5 than patients of the non-LN group (p<0.001 for all). These variables showed a statistically significant correlation with glomerular erythrocyturia, casts, Pr/Cr ratio, serum creatinine, eGFR, anti-dsDNA, uIL-5/Cr, and SLE disease activity index (all p<0.05).
  
  
  CONCLUSIONS
  These results provide evidence of increased urinary eosinophils, ECP and IL-5 in patients with SLE and LN; uECP/Cr ratio showed better correlation with markers of renal function and SLE disease activity.
authors.affiliation: Department of Clinical and Toxicological Analysis, Postgraduate Program in Health Sciences, Federal University of Rio Grande do Norte, Natal, RN Brazil.
authors.forename: Tereza Neuma Souza
authors.initials: TN
authors.lastname: Brito
authors.affiliation: Division of Rheumatology, Department of Clinical Medicine, Postgraduate Program in Health Sciences, Federal University of Rio Grande do Norte, Natal, RN Brazil.
authors.forename: Maria José
authors.initials: MJ
authors.lastname: Vilar
authors.affiliation: Division of Nephrology, Department of Integrated Medicine, Federal University of Rio Grande do Norte, Natal, RN Brazil.
authors.forename: José Bruno
authors.initials: JB
authors.lastname: Almeida
authors.affiliation: Clinical Hospital, University of São Paulo, Ribeirão Preto, SP Brazil.
authors.forename: Ana Luiza Souza Brito
authors.initials: AL
authors.lastname: Faria
authors.affiliation: Postgraduate Program in Health Sciences, Federal University of Rio Grande do Norte, Natal, RN Brazil.
authors.forename: Sarah Dantas Viana
authors.initials: SD
authors.lastname: Medeiros
authors.affiliation: Hospital Universitario Onofre Lopes, Federal University of Rio Grande do Norte, Natal, RN Brazil.
authors.forename: Maria Carmo Cardoso
authors.initials: MC
authors.lastname: Medeiros
authors.affiliation: Department of Clinical and Toxicological Analysis, Postgraduate Program in Health Sciences, Federal University of Rio Grande do Norte, Natal, RN Brazil.
authors.forename: Edna Marques Araújo
authors.initials: EM
authors.lastname: Silva
authors.affiliation: Postgraduate Program in Health Sciences, Federal University of Rio Grande do Norte, Natal, RN Brazil.
authors.forename: Vanessa Marques Araújo
authors.initials: VM
authors.lastname: Silva
authors.affiliation: Department of Clinical and Toxicological Analysis, Postgraduate in Pharmaceutical Sciences, Federal University of Rio Grande do Norte, Natal, RN Brazil.
authors.forename: Luanda Bárbara F Canário
authors.initials: LB
authors.lastname: Souza
authors.affiliation: Department of Clinical Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo (FMRP-USP), Ribeirão Preto, SP Brazil.
authors.forename: Luisa Karla P
authors.initials: LK
authors.lastname: Arruda
authors.affiliation: Postgraduate Program in Health Sciences, Federal University of Rio Grande do Norte, Natal, RN Brazil.
authors.forename: Tatiana Xavier
authors.initials: TX
authors.lastname: Costa
authors.affiliation: Department of Clinical and Toxicological Analysis, Postgraduate Program in Health Sciences, Federal University of Rio Grande do Norte, Natal, RN Brazil.
authors.forename: Geraldo Barroso Cavalcanti
authors.initials: GB
authors.lastname: Junior
authors.affiliation: Department of Pharmacy, Postgraduate Program in Health Sciences, Federal University of Rio Grande do Norte, Natal, RN Brazil.
authors.forename: Antonio G
authors.initials: AG
authors.lastname: Oliveira
authors.affiliation: Department of Clinical and Toxicological Analysis, Postgraduate Program in Health Sciences, Federal University of Rio Grande do Norte, Natal, RN Brazil.
authors.forename: Valéria Soraya Farias
authors.initials: VS
authors.lastname: Sales
keywords: Eosinophil cationic protein; Eosinophils; Interleukin-5; Systemic lupus erythematosus