Abstract: FR-PO934

Predicting Long-Term Renal and Patient Survival by Histological Diagnosis in Elderly Patients Undergoing a Renal Biopsy

Session Information

  • Geriatric Nephrology
    November 03, 2017 | Location: Hall H, Morial Convention Center
    Abstract Time: 10:00 AM - 10:00 AM

Category: Geriatric Nephrology

  • 901 Geriatric Nephrology

Authors

  • Navaratnarajah, Arunraj, Imperial College NHS Healthcare Trust, London, United Kingdom
  • Roufosse, Candice A., Imperial College NHS Healthcare Trust, London, United Kingdom
  • Cook, H. Terence, Imperial College NHS Healthcare Trust, London, United Kingdom
  • Willicombe, Michelle, Imperial College NHS Healthcare Trust, London, United Kingdom
Background

Evidence on long-term outcomes following renal biopsies in the elderly are lacking. This study aims to describe renal and patient outcomes in the elderly according to indication for biopsy, clinical parameters and histological diagnosis.

Methods

An analysis of 445 patients >70yrs old who had a renal biopsy between 2005 and 2015 was performed. Median age was 75.1yrs (70.1-91.0) and follow-up 5.8yrs.

Results

180/445 patients progressed to ESRD or died. 83/445 died without renal replacement therapy (RRT), 97/445 required RRT and 49/97 died after requiring RRT. This equates to 1, 3 and 5yr renal survival of 86.1, 80.1 and 76.9% and patient survival of 92.6, 82.8 and 72.3% respectively. Patients who progressed to ESRD were at higher risk of dying compared with those who remained dialysis independent, HR 2.54(1.64-2.93), p<0.0001.

Variables associated with risk of ESRD included higher serum creatinine (Cr) at time of biopsy [HR 1.005(1.004-1.007), p<0.0001] and biopsy for the indication of nephrotic syndrome (NS) with renal dysfunction [3.08(1.50-6.32), p=0.002]. Whilst having either histological features of GN [0.49(0.26-0.95, p=0.033] or TIN [0.075(0.01-0.55), p=0.01] were associated with dialysis independence.

Variables associated with reduced patient survival included increasing age [1.09(1.04-1.15), p=0.0004], Cr at time of biopsy [HR 1.0018(1.008-1.0028), p=0.0003], biopsy for NS with renal dysfunction [2.80(1.69-4.63), p=0.000] and histological diagnosis of MGRS [2.81(1.47-5.37), p=0.0017].

Those with tubulointerstitial scarring without a definite cause [HR 2.19(1.33-3.62), p=0.0011], GN [HR 2.07(1.16-3.70), p=0.006] and vasculitis [HR 3.56(1.68-7.50), p<0.0001] were at risk of progressing to ESRD before dying. There was no difference in risk of ESRD or death in patients with TIN, who had a good prognosis. Patients with MGRS also had no increased risk of ESRD over death, 1.36(0.52-3.60), p=0.52, however prognosis was poor with median time to death or dialysis 0.91yrs.

Conclusion

Renal biopsies in the elderly not only provide a histological diagnosis but also prognostic information on renal and patient survival. Data from this study may be useful for informed decision making by patients and nephrologists.

Histological FeatureGlomerulonephritis excluding vasculitis (GN)VasculitisTubulointerstitial nephritis (TIN)Monoclonal Gammopathy of Renal Significance (MGRS)Tubulointerstitial scarring without a definite cause
No. of patients (%)113 (25.4)56 (12.6)53 (11.9)29 (6.5)194 (43.6)