Cystatin-C and Creatinine Based Formulae for Estimation of Glomerular Filtration Rate in Renal Allograft Recipients.

Basu, G (2008) Cystatin-C and Creatinine Based Formulae for Estimation of Glomerular Filtration Rate in Renal Allograft Recipients. Masters thesis, Christian Medical College, Vellore.


Download (1MB) | Preview


INTRODUCTION : Research in renal transplantation has so far considered one-year acute rejection episodes, one-year graft and patient survival as short-term primary outcomes in evaluating therapeutic strategies. With recent advances in immunosuppression and care of a transplant recipient, the short-term renal transplant outcomes have been remarkably excellent. This makes evaluation of newer therapeutic strategies with such outcomes difficult. Meanwhile long-term results do not correlate well with these traditional shortterm end-points. Glomerular filtration rate is used as an indicator of renal function worldwide. Renal function in the short term has well been related to long term outcomes in renal transplantation. This calls for use of Glomerular filtration rate as a significant short term transplant outcome for further studies evaluating efficacy of newer therapeutic strategies and to identify prognostic indicators. Renal graft function assessment is now a primary criterion for evaluation of newer therapeutic interventions in transplantation. Assessment of renal function in a transplant recipient has always been a challenge. Most of currently existing methods of GFR measurement and estimation are not well validated in transplant recipients. Inulin Clearance is considered as goal standard in measurement of renal graft function. However, other traditionally accepted reference methods for direct measurement of GFR include use of exogenous markers like radiolabeled isotopes (51Cr EDTA, 99mTc-DTPA or 125I Iothalamate) and non-radioactive contrast agents (Iothalamate or Iohexol). Measurement of GFR in Indian population has been limited to the reference methods only as Inulin is currently not available in this country. In view of the cumbersome nature of these tests, several mathematical formulae based on endogenous markers of GFR such as S. Creatinine and Cystatin C have been developed AIM : To assess the performance characteristics of the various eGFR equations based on serum creatinine and serum Cystatin C in predicting the measured GFR in renal allograft recipients of Indian Subcontinent. OBJECTIVES : To study the agreement between GFR estimated by various prediction formulae based on Serum Creatinine and Cystatin C with the GFR measured by 99mTc DTPA renal scintigraphy among renal allograft recipients. To determine which estimated GFR prediction formula predicts GFR measured by 99mTc DTPA renal scintigraphy with precision and accuracy in renal allograft recipients. PATIENTS AND METHODS : Renal allograft recipients were studied at 6 months post transplant. GFR was measured by 99mTcDTPA scintigraphy (mGFR). Serum CystatinC & creatinine were measured. GFR was estimated (eGFR) by various S.Cr based and CysC based equations and compared with mGFR using correlation, bias, precision, accuracy and kappa statistics for agreement. RESULTS : 134 renal allograft recipients (M:F=101:33; age 34.0±11.5years) were studied. Mean mGFR was 52.1±22.6ml/min/1.73Sq.m. Overall, the S.Cr-eGFRs overestimated GFR [+15to20±25ml/min/1.73Sq.m.] and had poor correlation (ICC=0.0- 0.4), poor accuracy (@30%-35%; @50%-55%) and poor agreement (K= 0.05-0.20; 50- 60% misclassified) with mGFR. Among them, CG-LWGFR had marginal correlation (ICC=0.25-0.35), least bias (+4.0±22.4ml/min/1.73Sq.m) and most accuracy (@30%- 47.8%; @50%-72.1%). All CysC-eGFRs had better correlation (ICC=0.45-0.50), lower bias (-10to+1±20ml/min/1.73Sq.m), higher accuracy (@30%-60%; @50%-80%) and better agreement (K=0.25-0.45; 35-40% misclassified) with the mGFR. The Larsson, Macissac and MayoClinic CysC GFRs had the best performance characteristics. CONCLUSION : In renal allograft recipients, S.Cr-eGFR estimates poorly correlate, widely differ and rarely agree with the mGFR, compared to CysC-eGFR. The CysCeGFRs by Larsson, Macissac and MayoClinic provide the best GFR estimates. CysC is a better predictor of GFR than S.Cr at 6 months post transplantation.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Cystatin-C ; Creatinine Based Formulae ; Estimation of Glomerular Filtration Rate ; Renal Allograft Recipients.
Subjects: MEDICAL > Nephrology
Depositing User: Kambaraman B
Date Deposited: 11 Jul 2017 07:08
Last Modified: 11 Jul 2017 07:08

Actions (login required)

View Item View Item