title: Urinary CD4 T cells identify SLE patients with proliferative lupus nephritis and can be used to monitor treatment response.
abstract: OBJECTIVE
  Proliferative lupus nephritis (LN) is one of the major concerns in the treatment of systemic lupus erythematosus (SLE). Here we evaluate urinary CD4 T cells as a biomarker of active LN and indicator of treatment response.
  
  
  METHODS
  Urinary CD3CD4 T cells were quantified using flow cytometry in 186 urine samples from 147 patients with SLE. Fourteen patients were monitored as follow-up. Thirty-one patients with other nephropathies and 20 healthy volunteers were included as controls.
  
  
  RESULTS
  In SLE, urinary CD4 T cell counts ≥800/100 ml were observed exclusively in patients with active LN. Receiver operator characteristic analysis documented clear separation of SLE patients with active and non-active LN (area under the curve 0.9969). All patients with up-to-date kidney biopsy results showing proliferative LN had high urinary CD4 T cell numbers. In patients monitored under therapy, normalisation of urinary CD4 T cell counts indicated lower disease activity and better renal function. In contrast, patients with persistence of, or increase in, urinary T cells displayed worse outcomes.
  
  
  CONCLUSIONS
  Urinary CD4 T cells are a highly sensitive and specific marker for detecting proliferative LN in patients with SLE. Furthermore, monitoring urinary CD4 T cells may help to identify treatment responders and treatment failure and enable patient-tailored therapy in the future.
authors.affiliation: Department of Nephrology and Intensive Care Medicine, Charité Universitätsmedizin Berlin, , Berlin, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Enghard
authors.forename: Claudia
authors.initials: C
authors.lastname: Rieder
authors.forename: Katharina
authors.initials: K
authors.lastname: Kopetschke
authors.forename: J R
authors.initials: JR
authors.lastname: Klocke
authors.forename: Reinmar
authors.initials: R
authors.lastname: Undeutsch
authors.forename: Robert
authors.initials: R
authors.lastname: Biesen
authors.forename: Duska
authors.initials: D
authors.lastname: Dragun
authors.forename: Maik
authors.initials: M
authors.lastname: Gollasch
authors.forename: Udo
authors.initials: U
authors.lastname: Schneider
authors.forename: Karlfried
authors.initials: K
authors.lastname: Aupperle
authors.forename: Jens Y
authors.initials: JY
authors.lastname: Humrich
authors.forename: Falk
authors.initials: F
authors.lastname: Hiepe
authors.forename: Marina
authors.initials: M
authors.lastname: Backhaus
authors.forename: A H
authors.initials: AH
authors.lastname: Radbruch
authors.forename: Gerd R
authors.initials: GR
authors.lastname: Burmester
authors.forename: Gabriela
authors.initials: G
authors.lastname: Riemekasten
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000652:urine; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D003430:Cross-Sectional Studies; D016903:Drug Monitoring / Q000379:methods*; D005260:Female; D005434:Flow Cytometry; D005500:Follow-Up Studies; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D008181:Lupus Nephritis / Q000188:drug therapy / Q000276:immunology / Q000652:urine; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D014556:Urine / Q000166:cytology; D055815:Young Adult
chemical_list: D015415:Biomarkers; D007166:Immunosuppressive Agents
keywords: Autoimmune Diseases; Inflammation; Lupus Nephritis; Systemic Lupus Erythematosus; T Cells