title: Case series: CTLA4-IgG1 therapy in minimal change disease and focal segmental glomerulosclerosis.
abstract: BACKGROUND
  Minimal Change Disease (MCD) in relapse is associated with increased podocyte CD80 expression and elevated urinary CD80 excretion, whereas focal segmental glomerulosclerosis (FSGS) has mild or absent CD80 podocyte expression and normal urinary CD80 excretion.
  
  
  METHODS
  One patient with MCD, one patient with primary FSGS and three patients with recurrent FSGS after transplantation received CD80 blocking antibodies (abatacept or belatacept). Urinary CD80 and CTLA-4 levels were measured by ELISA. Glomeruli were stained for CD80.
  
  
  RESULTS
  After abatacept therapy, urinary CD80 became undetectable with a concomitant transient resolution of proteinuria in the MCD patient. In contrast, proteinuria remained unchanged after abatacept or belatacept therapy in the one patient with primary FSGS and in two of the three patients with recurrent FSGS despite the presence of mild CD80 glomerular expression but normal urinary CD80 excretion. The third patient with recurrent FSGS after transplantation had elevated urinary CD80 excretion immediately after surgery which fell spontaneously before the initiation of abatacept therapy; after abatacept therapy, his proteinuria remained unchanged for 5 days despite normal urinary CD80 excretion.
  
  
  CONCLUSIONS
  These observations are consistent with a role of podocyte CD80 in the development of proteinuria in MCD. In contrast, CD80 may not play a role in recurrent FSGS since the urinary CD80 of our three patients with recurrent FSGS was only increased transiently after surgery and normalization of urinary CD80 did not result in resolution of proteinuria.
authors.affiliation: Division of Pediatric Nephrology, Department of Pediatrics, University of Florida, 1600 SW Archer Rd., HD214, Gainesville, FL, 32610, USA, garineh@peds.ufl.edu.
authors.forename: Eduardo H
authors.initials: EH
authors.lastname: Garin
authors.forename: Jochen
authors.initials: J
authors.lastname: Reiser
authors.forename: Gabriel
authors.initials: G
authors.lastname: Cara-Fuentes
authors.forename: Changli
authors.initials: C
authors.lastname: Wei
authors.forename: Dany
authors.initials: D
authors.lastname: Matar
authors.forename: Heiman
authors.initials: H
authors.lastname: Wang
authors.forename: Nada
authors.initials: N
authors.lastname: Alachkar
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Johnson
mesh_terms: D000069594:Abatacept / Q000627:therapeutic use; D000293:Adolescent; D000328:Adult; D060908:CTLA-4 Antigen / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005923:Glomerulosclerosis, Focal Segmental / Q000188:drug therapy* / Q000652:urine; D006801:Humans; D007074:Immunoglobulin G / Q000627:therapeutic use*; D007155:Immunologic Factors / Q000627:therapeutic use*; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008297:Male; D009402:Nephrosis, Lipoid / Q000188:drug therapy* / Q000652:urine; D055815:Young Adult
chemical_list: D060908:CTLA-4 Antigen; D007074:Immunoglobulin G; D007155:Immunologic Factors; D007166:Immunosuppressive Agents; D000069594:Abatacept