Time-averaged proteinuria during follow-up and renal prognosis in patients with biopsy-proven benign nephrosclerosis

BACKGROUND

Heavy proteinuria at diagnostic renal biopsy has been reported as an independent risk factor for deteriorating renal function in benign nephrosclerosis (BNS). However, studies investigating the relationship between the amount of proteinuria during follow-up and long-term renal prognosis in BNS are limited. This study aimed to assess the relationship between time-averaged proteinuria (TAP) and renal prognosis in BNS.

METHODS

The study participants included 98 patients with biopsy-proven BNS (average age 52 ± 13 years, estimated glomerular filtration rate (eGFR) 53 ± 25 ml/min/1.73 m², urine protein excretion at baseline 1.34 ± 1.30 g/gCr) from the Jikei University Hospital. Multivariate analysis was used to investigate the effects of TAP and other clinicopathological findings on the risk for renal outcome in biopsy-proven BNS (a 30% decline in eGFR from baseline or end-stage renal disease). Proteinuria was measured every 6 months and the mean value was used as an indicator of TAP.

RESULTS

The average observation period was 56 ± 43 months. In the unadjusted model, higher levels of TAP and urinary protein at baseline, glomerulosclerosis, and tubulointerstitial damage were associated with renal prognosis. The adjusted model demonstrated a significant association between TAP and renal outcomes (hazard ratio 5.45, 95% confidence interval 3.02-10.7), which was independent of higher baseline proteinuria, glomerulosclerosis, and tubulointerstitial damage.

CONCLUSIONS

TAP is an independent risk factor for renal prognosis in patients with BNS, indicating the significance of urinary protein excretion during follow-up for the progression of BNS. Clinicians should understand the importance of follow-up evaluation for proteinuria in patients with BNS.

Development and validation of a new prediction model for graft function using preoperative marginal factors in living-donor kidney transplantation

BACKGROUND

Recently, living-donor kidney transplantation from marginal donors has been increasing. However, a simple prediction model for graft function including preoperative marginal factors is limited. Here, we developed and validated a new prediction model for graft function using preoperative marginal factors in living-donor kidney transplantation.

METHODS

We retrospectively investigated 343 patients who underwent living-donor kidney transplantation at Kyushu University Hospital (derivation cohort). Low graft function was defined as an estimated glomerular filtration rate of < 45 mL/min/1.73 m² at 1 year. A prediction model was developed using a multivariable logistic regression model, and verified using data from 232 patients who underwent living-donor kidney transplantation at Tokyo Women's Medical University Hospital (validation cohort).

RESULTS

In the derivation cohort, 89 patients (25.9%) had low graft function at 1 year. Donor age, donor-estimated glomerular filtration rate, donor hypertension, and donor/recipient body weight ratio were selected as predictive factors. This model demonstrated modest discrimination (c-statistic = 0.77) and calibration (Hosmer-Lemeshow test, P = 0.83). Furthermore, this model demonstrated good discrimination (c-statistic = 0.76) and calibration (Hosmer-Lemeshow test, P = 0.54) in the validation cohort. Furthermore, donor age, donor-estimated glomerular filtration rate, and donor hypertension were strongly associated with glomerulosclerosis and atherosclerotic vascular changes in the "zero-time" biopsy.

CONCLUSIONS

This model using four pre-operative variables will be a simple, but useful guide to estimate graft function at 1 year after kidney transplantation, especially in marginal donors, in the clinical setting.

Clinico-pathological characteristics and outcomes of patients with biopsy-proven hypertensive nephrosclerosis: a retrospective cohort study

Background

This study aimed to investigate renal outcomes and their predictors in biopsy-proven hypertensive nephrosclerosis (HN) patients and to compare clinico-pathological characteristics and prognoses between benign nephrosclerosis (BN) and malignant nephrosclerosis (MN) patients.

Methods

Data for biopsy-proven HN patients were retrospectively analyzed. Renal survival rates and relationships between clinico-pathological characteristics and outcomes were assessed.

Results

A total of 194 patients were enrolled; the mean age at biopsy was 43.8 years, and male gender predominated (82.5 %). The median duration of hypertension was 5.0 years, and the mean systolic and diastolic blood pressures were 195 ± 37 and 126 ± 26 mmHg, respectively. The median serum creatinine (Scr) level, estimated glomerular filtration rate (eGFR), and proteinuria level were 1.61 mg/dl, 49.6 ml/min/1.73 m², and 0.80 g/24 h, respectively. BN and MN were found by renal biopsy in 55.2 % and 44.8 % of patients, respectively. At biopsy, MN patients were younger, and had higher median Scr and proteinuria levels, higher incidences of anemia, hypertensive heart disease and hypertensive retinopathy, and worse renal outcomes than BN patients. During a median follow-up period of 3.0 years, 36 patients (18.6 %) reached end-stage renal disease (ESRD), and the 5- and 10-year cumulative renal survival rates for HN patients were 84.5 % and 48.9 %, respectively. A decreased baseline eGFR, an increased baseline proteinuria level, anemia, increased percentage of global glomerulosclerosis and tubular atrophy and interstitial fibrosis (TAIF) were independent predictors of future ESRD.

Conclusions

The clinico-pathological characteristics and prognoses were significantly different between the MN and BN patients. The renal outcomes of HN patients were independently associated with the baseline eGFR and proteinuria level, anemia, percentage of global glomerulosclerosis and TAIF.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-016-0254-2) contains supplementary material, which is available to authorized users.