title: Multiple kidney cysts in thin basement membrane disease with proteinuria and kidney function impairment.
abstract: BACKGROUND
  Some patients with thin basement membrane disease (TBMD) develop proteinuria, hypertension and different degrees of CKD, besides the persistent microhaematuria characteristic of the disease. Little is known about factors associated with this unfavourable outcome.
  
  
  METHODS
  We reviewed clinical, pathological and radiological features of 32 patients with biopsy-proven TBMD. Patients were divided in two groups: those with persistent normal kidney function and negative or minimal proteinuria (n = 16) and those with persistent proteinuria >0.5 g/day (n = 16).
  
  
  RESULTS
  Patients with proteinuria had a worse kidney function at baseline than those with negative proteinuria. Global or segmental glomerulosclerosis, together with interstitial fibrosis, was found in 37% of patients with proteinuria. All proteinuric patients were treated with renin-angiotensin system blockers. At the end of follow-up (198 months in proteinuric patients and 210 months in patients with negative proteinuria) the prevalence of hypertension was 68% in proteinuric patients (12% at baseline), compared with 12 and 6%, respectively, in non-proteinuric patients. A slow decline of renal function was observed in proteinuric patients, although no patient developed end-stage kidney disease. Ultrasound studies showed bilateral kidney cysts in nine patients (56%) with proteinuria. Cysts were bilateral and countless in six patients, and bilateral but with a limited number of cysts in the three remaining patients. No cysts were found in patients with negative proteinuria.
  
  
  CONCLUSIONS
  Some patients with TBMD develop hypertension, proteinuria and CKD. Multiple bilateral kidney cysts were found in a majority (56%) of these patients. Further studies are needed to investigate the pathogenesis and the influence on long-term outcome of this TBMD-associated multiple kidney cysts.
authors: Department of Nephrology , 12 de Octubre University Hospital , Madrid , Spain.
authors: Angel M
authors: AM
authors: Sevillano
authors: Department of Nephrology , 12 de Octubre University Hospital , Madrid , Spain.
authors: Eduardo
authors: E
authors: Gutierrez
authors: Department of Nephrology , 12 de Octubre University Hospital , Madrid , Spain.
authors: Enrique
authors: E
authors: Morales
authors: Department of Nephrology , 12 de Octubre University Hospital , Madrid , Spain.
authors: Eduardo
authors: E
authors: Hernandez
authors: Department of Nephrology , 12 de Octubre University Hospital , Madrid , Spain.
authors: Maria
authors: M
authors: Molina
authors: Department of Nephrology , 12 de Octubre University Hospital , Madrid , Spain.
authors: Ester
authors: E
authors: Gonzalez
authors: Department of Nephrology , 12 de Octubre University Hospital , Madrid , Spain ; Department of Medicine , Complutense University , Madrid , Spain.
authors: Manuel
authors: M
authors: Praga
keywords: cysts; proteinuria; renal function impairment; thin basement membrane disease