Comparison between ^99mTc-diethylenetriaminepentaacetic acid two sample method, modification of diet for renal disease equation and chronic kidney disease epidemiology collaboration equation based estimated glomerular filtration rate values in Indian donors for renal transplantation

Glomerular filtration rate (GFR) by plasma sampling technique is considered to be accurate in selection of donors for renal transplantation. Estimate GFR (eGFR) calculations using modification of diet for renal disease (MDRD) equation and chronic kidney disease epidemiology collaboration (CKD-EPI) are simple methods but have not been validated in the Indian population. Hence, we aimed to assess the correlation between these three techniques. The plasma sampling technique was done using two samples at 60 and 180 min after injection of 1 mCi (37 MBq) ^99mTc-diethylenetriaminepentaacetic acid (DTPA) to 28 healthy donors. Age, sex, height, weight, and plasma creatinine were recorded. Creatinine estimation was done by modified Jaffe's technique. Normalized GFR (nGFR) by two-sample method and eGFR (for MDRD and CKD-EPI) values were calculated using formulas. There were 8 males and 20 females. The mean age was 48.25 years (27-68 years). The mean height was 154.2 cm while mean weight was 55.6 kg. The mean nGFR value was 79.92 for two-sample method while mean eGFR value for MDRD and CKD-EPI were 93.72 and 101.44 ml/min/1.73 m² (eligibility value at our institution = 70), respectively. While the correlation between nGFR and eGFR MDRD was poor (correlation coefficient = 0.395), nGFR and eGFR CKD-EPI had a moderate correlation (0.704). Mean total bias between nGFR and eGFR MDRD and CKD-EPI are 13.79 and 21.51, respectively. eGFR MDRD of 68% patients fell within 30% of nGFR (P30) while P30 for eGFR CKD-EPI was 57%. Because of the large variability in eGFR MDRD and CKD-EPI, nGFR estimation using an alternative method like the plasma sampling technique using ^99mTc-DTPA appears necessary while screening healthy donors for renal transplantation. (author)