Low Glomerular Filtration Rate in Apparently Healthy Young Individuals is an Important Factor Preventing Kidney Transplantation from Living Kidney Donors – A Single-Center Observational Study from India

Abstract

Background: India performed 7936 kidney transplantation operations in 2018 with living donor as the source in 85%. Identifying a living kidney donor (LKD) is difficult due to medical, social, and regulatory barriers. In addition, only a proportion of patients who volunteer may be able to donate eventually. Despite living donors being the predominant source, there are very few studies addressing the factors influencing living donor kidney donation in India. Methods: We analyzed data from our prospective LKD registry between July 1, 2011 and June 31, 2018. Demographic details, medical history, serum creatinine, and measured glomerular filtration rate (mGFR), blood pressure and the eventual outcome of LKD evaluation, including reason for noneligibility were collected. In a prospective cohort of 12 LKDs, renal functional reserve was studied using protein loading and dietary protein intake was measured from urine urea nitrogen excretion. Results: Over a period of 81 months, 316 LKDs were enrolled in our program. On 101 instances factors related to recipients prevented transplantation and on 92 occasions donor related factors precluded donation. Among 182 medically eligible LKDs with no evidence of CKD, only 33% had mGFR >90 ml/min/1.73 m2. Based on our institutional criteria, 22% of LKDs with mGFR <70 ml/min/1.73 m2 were ineligible solely based this criterion. Eventually, only 32% of enrolled LKDs were accepted for donation. Dietary protein intake was low in all 12 LKDs studied, only one had mGFR >90 ml/min/1.73 m2. Eight LKDs with mGFR <90 ml/min/1.73 m2 showed renal functional reserve of more than 20% with protein loading. Conclusion: Only one-third of voluntary kidney donors enrolled for evaluation were eventually able to donate their kidney. Low mGFR in otherwise apparently healthy LKDs was an important reason precluding kidney donation. Only 33% of individual found medically fit for donation had a mGFR ≥90 ml/min/m2 at our center. Low dietary protein intake may be a factor contributing to low mGFR in healthy LKDs.