2010 - TTS International Congress


This page contains exclusive content for the member of the following sections: TTS. Log in to view.

Laboratory Immunology and Kidney Transplantation

102.2 - Predicting Outcomes in Kidney Transplantation: A Comparison of Three Semi-Quantitative Proteinuria Tests

Presenter: Bryce, Kiberd, Halifax, Canada
Authors: Kiberd B.

PREDICTING OUTCOMES IN KIDNEY TRANSPLANTATION: A COMPARISON OF THREE SEMI-QUANTITATIVE PROTEINURIA TESTS

LABORATORY IMMUNOLOGY AND KIDNEY TRANSPLANTATION

B. Kiberd
, Dalhousie University, Halifax/NS/CANADA

Body: Introduction: Proteinuria is an important predictor of outcomes in kidney transplant recipients. However there is little information on the relative advantages of albumin:creatinine ratio (ACR) in comparison to protein:creatinine ratio (PCR) or conventional dipstick evaluation. Methods: Adult functioning (> 6 months) kidney transplant recipients (n=500) from a single center had a baseline urine tested by conventional dipstick, ACR and PCR. We defined hard outcome endpoints as graft loss and death. Results: Over a median follow up of 2.6 years there were 50 events (21 deaths and 29 graft loss) or 4.4 events per 100 pt-yrs. All 3 semi-quanitative methods were very predictive of an event (see figure). PCR had the highest c-statistic (0.797, 95% CI 0.732-0.861), followed by ACR (0.785, 95% CI, 0.714-0.855) and dipstick (0.716, 95% CI 0.625-0.806). Proteinuria grades (ref=normal, mild, or moderate) were examined in an unadjusted Cox model separately for ACR (<30 mg/g, 30-299 mg/g, >300 mg/g), PCR (<130 mg/g, 130-490 mg/g, >490 mg/g) and dipstick (negative, trac/0.3 g/L, 1.0 g/L+). The HR for mild and moderate grades relative to normal were ACR (mild 3.7, p=0.002, moderate 9.9, p<0.001), PCR (mild 3.1, p=0.011, moderate 8.9 p<0.001) and dipstick (mild 2.3, p=0.015, moderate 6.2, p<0.001). In a multivariate Cox model adjusted for age, gender, organ source, duration of function, systolic blood pressure, BMI, diabetes, smoking and cardiovascular disease, eGFR (HR 0.954 per ml/min/1.73m2, 95% CI 0.935-0.974, p<0.001), the use of ACEi/ARB (HR 0.538, 95% CI 0.295-0.984, p=0.044) and proteinuria were predictive of outcomes. The above proteinuria grades for ACR, PCR and dipstick were examined separately in this adjusted model. The HR for mild and moderate grades relative to normal were ACR (mild 2.0, p=0.125, moderate 4.5 p=0.001), PCR (mild 1.9, p=0.191, moderate 4.1 p=0.002) and dipstick (mild 1.3 p=0.558, moderate 2.8 p=0.011). New onset proteinuria was also examined in the 320 patients without proteinuria by dipstick at baseline. Of these 88 (29%) had an ACR >30 mg/g. In those dipstick negative but ACR positive, 49% (20%/year) became dipstick positive at last follow up. In those dipstick negative and ACR negative, only 14% (5.6%/year) became dipstick positive. Conclusions: All 3 proteinuria tests are predictive of outcomes and their use may depend on affordability. Small levels of proteinuria were predictive of adverse events. There appears to be very little difference in ACR vs. PCR but both have some advantage over dipstick. ACEi/ARB were associated with fewer endpoints.

Disclosure: All authors have declared no conflicts of interest.


Important Disclaimer

By viewing the material on this site you understand and accept that:

  1. The opinions and statements expressed on this site reflect the views of the author or authors and do not necessarily reflect those of The Transplantation Society and/or its Sections.
  2. The hosting of material on The Transplantation Society site does not signify endorsement of this material by The Transplantation Society and/or its Sections.
  3. The material is solely for educational purposes for qualified health care professionals.
  4. The Transplantation Society and/or its Sections are not liable for any decision made or action taken based on the information contained in the material on this site.
  5. The information cannot be used as a substitute for professional care.
  6. The information does not represent a standard of care.
  7. No physician-patient relationship is being established.

Social

Contact

Staff Directory
+1-514-874-1717
info@tts.org

Address

The Transplantation Society
International Headquarters
740 Notre-Dame Ouest
Suite 1245
Montréal, QC, H3C 3X6
Canada