title: The value of repeat kidney biopsy in quiescent Argentinian lupus nephritis patients.
abstract: BACKGROUND
  The duration of maintenance therapy after induction therapy for lupus nephritis has not been rigorously established. A common practice is to maintain immunosuppression for 1-2 years after complete remission, and longer for partial remission. The present work addresses whether a repeat kidney biopsy might be informative in deciding who should continue immunosuppression after complete or partial remission.
  
  
  METHODS
  The practice in a large Buenos Aires nephrology unit is to repeat a kidney biopsy before finalizing the decision to withdraw or continue immunosuppression. This work reports on a cohort of 25 Hispanic patients that had two or more kidney biopsies, the last occurring after at least 24 months of clinically quiescent disease.
  
  
  RESULTS
  Despite normalization of serum creatinine and reduction of proteinuria to <500 mg/d, 30% of patients still had significant activity at the last biopsy. Conversely, 60% of patients with ongoing proteinuria (500-1000 mg/d), or stable but abnormal serum creatinine, had no activity by biopsy. Univariate association analyses demonstrated that improvement in the activity index (AI) of the last biopsy was associated with choice of induction therapy (cyclophosphamide or mycophenolate), improvement in serum creatinine over the first six months of treatment, and improvement in complement component C4. By multivariate regression analyses, two AI prediction models emerged. Cyclophosphamide plus change in serum creatinine or cyclophosphamide plus change in C4 accounted for 50% of the improvement in AI.
  
  
  CONCLUSIONS
  These data suggest that a repeat biopsy may be useful in making the decision to withdraw or continue maintenance immunosuppression.
authors.affiliation: Nephrology Division, The Ohio State University Wexner Medical Center, Ohio, USA.
authors.forename: A S
authors.initials: AS
authors.lastname: Alvarado
authors.affiliation: Nephrology Division, Hospital Fernandez, Buenos Aires, Argentina.
authors.forename: A
authors.initials: A
authors.lastname: Malvar
authors.affiliation: Nephrology Division, Hospital Fernandez, Buenos Aires, Argentina.
authors.forename: B
authors.initials: B
authors.lastname: Lococo
authors.affiliation: Pathology Department, Hospital Fernandez, Buenos Aires, Argentina.
authors.forename: V
authors.initials: V
authors.lastname: Alberton
authors.affiliation: Centro de Diagnostico Patologico, Buenos Aires, Argentina.
authors.forename: F
authors.initials: F
authors.lastname: Toniolo
authors.affiliation: The Ohio State University College of Public Health, Ohio, USA.
authors.forename: H N
authors.initials: HN
authors.lastname: Nagaraja
authors.affiliation: Nephrology Division, The Ohio State University Wexner Medical Center, Ohio, USA rovin.1@osu.edu.
authors.forename: B H
authors.initials: BH
authors.lastname: Rovin
mesh_terms: D000328:Adult; D001118:Argentina; D001706:Biopsy / Q000379:methods; D000066491:Clinical Decision-Making; D005260:Female; D006801:Humans; D007165:Immunosuppression Therapy; D007668:Kidney / Q000473:pathology*; D008181:Lupus Nephritis / Q000188:drug therapy* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012074:Remission Induction; D012189:Retrospective Studies; D055815:Young Adult
keywords: Systemic lupus erythematosus; activity index; chronicity index; renal response