Thrombotic microangiopathy in United States long-term dialysis patients

Nephrol Dial Transplant. 2006 Jan;21(1):191-6. doi: 10.1093/ndt/gfi153. Epub 2005 Oct 4.


Background: The incidence, risk factors, recurrence rates and prognosis of thrombotic microangiopathy (TMA) among long-term dialysis patients in the United States have not been previously described in a national population.

Methods: 272 024 Medicare primary patients in the United States Renal Data System (USRDS) initiated on end-stage renal disease (ESRD) therapy between 1 April 1995 and 31 December 1999 with Medicare as primary payer were analysed in a retrospective cohort study of USRDS of TMA. Cox regression was used to calculate adjusted hazard ratios (AHR) for risk of TMA and risk of death after TMA.

Results: The incidence of TMA in the first year of dialysis was 0.5% overall. Among patients with renal failure due to haemolytic uraemic syndrome (HUS), the incidence of TMA was highest in the first year of dialysis (HUS, 11.3% first year, 4.5% per year thereafter), while among patients without HUS the incidence of TMA was much lower and more constant over time (0.3% per year). In Cox regression analysis, independent risk factors for TMA were renal failure due to HUS (adjusted hazard ratio (AHR) 179, 95% CI 95-338), paediatric age (<or=18 years vs older, AHR 2.59, 95% CI 1.48-4.55), female gender (AHR 1.99, 95% CI 1.43-2.78), and systemic lupus erythematosus (SLE, AHR 3.66, 95% CI 1.49-8.51). One-year survival after TMA was poor at 58% (AHR for mortality 2.04, 95% CI 1.23-3.38).

Conclusions: TMA is an uncommon cause of hospitalization after dialysis, but does recur in patients with HUS at a substantial rate. Younger age and SLE were risk factors for new onset TMA, which was associated with poor survival. Vigilant monitoring of select patients with HUS-related ESRD and higher-risk patients with SLE is warranted in the dialysis population.

Publication types

  • Comparative Study

MeSH terms

  • Age Distribution
  • Aged
  • Aged, 80 and over
  • Comorbidity
  • Female
  • Follow-Up Studies
  • Hemolytic-Uremic Syndrome / diagnosis
  • Hemolytic-Uremic Syndrome / epidemiology
  • Hemolytic-Uremic Syndrome / therapy
  • Humans
  • Kidney Failure, Chronic / diagnosis
  • Kidney Failure, Chronic / epidemiology*
  • Kidney Failure, Chronic / therapy*
  • Kidney Function Tests
  • Male
  • Middle Aged
  • Prevalence
  • Probability
  • Proportional Hazards Models
  • Purpura, Thrombotic Thrombocytopenic / epidemiology*
  • Purpura, Thrombotic Thrombocytopenic / etiology
  • Registries
  • Renal Dialysis / adverse effects*
  • Renal Dialysis / methods
  • Retrospective Studies
  • Risk Assessment
  • Severity of Illness Index
  • Sex Distribution
  • Time Factors
  • Treatment Outcome
  • United States / epidemiology