title: Renal resistive index early detects chronic tubulointerstitial nephropathy in normo- and hypertensive patients.
abstract: BACKGROUND
  We studied whether the measurement of intrarenal vascular resistance by Doppler ultrasonography, capable of investigating renal interstitial compartment, allows the early detection of chronic tubulointerstitial nephropathy (TIN).
  
  
  METHODS
  30 normotensive and 28 hypertensive (I-II OMS) patients with a clinical history suggestive of chronic TIN and normal renal function were enrolled. 40 healthy volunteers served as controls. Patients were considered TIN-negative or TIN-positive after investigating tubular function by urine concentrating and acidification tests. Renal sonographic parameters and renal resistive index (RRI) were obtained by duplex scanner. Glomerular filtration rate/effective renal plasmatic flow ratio was investigated by sequential renal scintigraphy in TIN-negative and TIN-positive patients; (99m)Tc-DMSA scintigraphy was also performed in TIN-positive patients.
  
  
  RESULTS
  RRI values of TIN-positive normotensive and hypertensive patients were significantly higher (p < 0.01 for both) than those of TIN-negative patients and of controls. RRI values resulted to be linearly related to uricemia (r = 0.88, p < 0.0001) only in normotensive patients. RRI values also resulted to be linearly related to filtration ratio values (r = 0.60, p < 0.0001). (99m)Tc-DMSA scintigraphy confirmed interstitial renal damage (grade 1 and 2).
  
  
  CONCLUSIONS
  RRI measurement allows the early identification of both normotensive and hypertensive patients with chronic TIN and signs of tubular dysfunction, when renal function is still preserved.
authors.affiliation: Clinica Medica Generale e Cardiologia, Dipartimento di Area Critica Medico-Chirurgica, University of Florence, Florence, Italy. m.boddi@dfc.unifi.it
authors.forename: Maria
authors.initials: M
authors.lastname: Boddi
authors.forename: Ilaria
authors.initials: I
authors.lastname: Cecioni
authors.forename: Loredana
authors.initials: L
authors.lastname: Poggesi
authors.forename: Francesca
authors.initials: F
authors.lastname: Fiorentino
authors.forename: Katia
authors.initials: K
authors.lastname: Olianti
authors.forename: Sabino
authors.initials: S
authors.lastname: Berardino
authors.forename: Giuseppe
authors.initials: G
authors.lastname: La Cava
authors.forename: GianFranco
authors.initials: G
authors.lastname: Gensini
mesh_terms: D000328:Adult; D002908:Chronic Disease; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D006973:Hypertension / Q000150:complications*; D007668:Kidney / Q000098:blood supply*; D007671:Kidney Concentrating Ability; D007684:Kidney Tubules / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009395:Nephritis, Interstitial / Q000175:diagnosis*; D011877:Radionuclide Imaging; D017596:Renal Plasma Flow, Effective; D019783:Technetium Tc 99m Dimercaptosuccinic Acid; D018608:Ultrasonography, Doppler; D014655:Vascular Resistance
chemical_list: D019783:Technetium Tc 99m Dimercaptosuccinic Acid