Relative contribution of morphometric and functional indicators of tubulointerstitial lesion to glomerular diseases prognosis.

BACKGROUND

Early diagnosis of proximal tubular lesions can be achieved by detecting abnormal levels of low molecular weight proteins in urine.

MATERIAL AND

METHODS

100 cases of glomerulopathies were retrospectively studied to establish the profile of urinary levels of retinol-binding protein (urRBP) and their correlation with histological markers of tubulointerstitial lesions in renal biopsies. The histological study included staining with picrosirius red.

RESULTS

Nonproliferative glomerulopathies, male sex, white race and young adults were predominant. The chance of abnormal urRBP occurring was higher among patients with a predominant proliferative component, baseline serum creatinine >1.2 mg/dl (p = 0.008), creatinine clearance <70 ml/min (p = 0.006), and severe interstitial fibrosis (p = 0.042). In multivariate analysis, only serum creatinine and creatinine clearance were independently associated to urRBP, and only urRBP was a time-independent prognostic factor for survival without renal failure (risk of renal failure: 9x).

CONCLUSION

Our study suggests that urRBP determination is prognostically relevant in the progression of glomerulopathies; on the other hand, the evaluated morphometric markers correlated poorly with the clinical outcome of these patients. Consequently, urRBP determination, as a functional marker of tubulointerstitial damage, was more appropriate for determining the prognosis of glomerular diseases than the morphometric analysis of renal biopsies.