Obesity in renal transplantation: The role of induction therapy on long-term outcomes

Obesity is a burgeoning problem among renal transplant recipients given its association with increased morbidity, graft loss, and mortality. The long-term influence of different induction therapies in obese compared to nonobese patients is uncertain. We examined the long-term effect of low-dose rabbit antithymocyte globulin (rATG; 35 mg/kg) induction therapy compared to two doses of 20 mg basiliximab (BSX) in nonobese and obese renal transplant patients. The medical records of all adult (>18 years) recipients of kidney transplants between June 2001 and June 2009 in our center were reviewed. Patients whose body mass index (BMI) was greater than 30 were considered to be obese. The average dose of rATG was 3.2 ± 1.6 mg/kg. A total of 475 patients were included. In the nonobese group with a BMI less than 30, 68 received BSX and 247, rATG. In the obese group, 27 patients were given BSX and 133 were given rATG. Mean follow-up was 1523 days. These four groups were similar in baseline characteristics including: donor and recipient age, percent diabetes, living donors, panel-reactive antibodies > 35, HLA mismatch, race, gender, and maintenance immunosuppression. Serum creatinine levels at 3 months and 1, 5, and 7 years were not statistically different between groups. Compared to BSX induction therapy, rATG was associated with better graft survival at 47.4 ± 10 months in obese (63.6% vs 90.3%, P < .05, respectively) as well as nonobese patients (68.2% vs 88.7%, P < .05, respectively). Rejections were numerically lower in rATG-treated obese patients, which reached statistical significance in nonobese patients. Wound and viral infections were not statistically different between rATG and BSX groups. Therefore, low-dose rATG is associated with a better long-term graft survival rate in obese patients without incurring an increased risk of infectious complications. When rATG was used in obese and nonobese patients, there was no difference in graft and patient survival.