title: Tubulointerstitial lesions in lupus nephritis: International multicentre study in a large cohort of patients with repeat biopsy.
abstract: BACKGROUND
  The glomerulocentric International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification is the gold standard for the evaluation of lupus nephritis, while tubulointerstitial (TIN) parameters are often under-recognized in pathological reports.
  
  
  METHODS
  Renal biopsies from 142 patients who underwent repeat biopsy (RB) were evaluated for the following histological parameters: (i) inflammatory interstitial infiltrates; (ii) interstitial fibrosis; (iii) tubulitis; and (iv) tubular atrophy. The inter-relationships between the four TIN variables were explored by multivariate analysis. A linear mixed model was used to investigate the potential impact of TIN variables on eGFR and proteinuria at the two biopsy occasions.
  
  
  RESULTS
  The study showed that moderate-severe lesions were not so frequent at the reference biopsy, but more extensively represented upon RB. A strong association was found between the two inflammatory indices and between those related to chronic damage, while the relationship with the ISN/RPS classification was present at RB. If class IV-G was the most related with TIN (especially at RB), the existence of primary TIN in class II patients was also confirmed. Finally, our results support the hypothesis that tubulitis is an independent predictive factor for eGFR.
  
  
  CONCLUSIONS
  We recommend that the standard histological evaluation of SLE nephritis also includes TIN features.
authors.affiliation: Department of Surgery and Translational Medicine, Pathology, San Gerardo Hospital, University of Milano-Bicocca, Monza, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Pagni
authors.affiliation: Department of Health Sciences, Center of Biostatistics for Clinical Epidemiology, University of Milano-Bicocca, Monza, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Galimberti
authors.affiliation: Nephrology Unit, Desio Hospital, Desio, Italy.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Galbiati
authors.affiliation: Department of Health Sciences, Center of Biostatistics for Clinical Epidemiology, University of Milano-Bicocca, Monza, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Rebora
authors.affiliation: Department of Health Sciences, University of Milano-Bicocca, Monza, Italy.
authors.forename: Veronica
authors.initials: V
authors.lastname: Pietropaolo
authors.affiliation: Department of Health Sciences, University of Milano-Bicocca, Monza, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Pieruzzi
authors.affiliation: Department of Health Sciences, University of Milano-Bicocca, Monza, Italy.
authors.forename: Andrew James
authors.initials: AJ
authors.lastname: Smith
authors.affiliation: Department of Pathology, Nephropathology Centre, University of Milano-Bicocca, Monza, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Ferrario
mesh_terms: D000328:Adult; D001284:Atrophy; D001706:Biopsy; D016009:Chi-Square Distribution; D005260:Female; D005355:Fibrosis; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000473:pathology* / Q000503:physiopathology; D016014:Linear Models; D016015:Logistic Models; D008181:Lupus Nephritis / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D015999:Multivariate Analysis; D009395:Nephritis, Interstitial / Q000473:pathology* / Q000503:physiopathology; D011237:Predictive Value of Tests; D011379:Prognosis; D011507:Proteinuria / Q000473:pathology / Q000503:physiopathology; D012189:Retrospective Studies; D012720:Severity of Illness Index; D055815:Young Adult
keywords: International Society of Nephrology/Renal Pathology Society classification; lupus nephritis; lupus tubulointerstitial nephritis; repeat biopsy