Abstract: TH-PO955

Creatinine Monitoring by Remote Blood Spot Testing in Pediatric Kidney Transplant Recipients

Session Information

Category: Transplantation

  • 1702 Transplantation: Clinical and Translational

Authors

  • Sinkey, Marian, Seattle Children''s, Seattle, Washington, United States
  • Dickerson, Jane, Seattle Children''s Hospital, Seattle, Washington, United States
  • Smith, Jodi M., Children's Hospital & Regional Medical Center, Seattle, Washington, United States
Background

Pediatric kidney transplant patients are monitored frequently with laboratory testing to assess kidney transplant function and optimize therapeutic drug doses. Dried blood spots could reduce the number of lab trips, benefiting those who are remote, elderly, working, or unable to travel.

Methods

We collected 35 samples via phlebotomy from 30 participants for simultaneously paired venous and finger-poke (capillary) to assess the correlation of venous plasma creatinine with capillary dried blood spot creatinine (DBS had already been validated for immunosuppression levels (1)). This method uses creatinine-d3 as the calibrators, and creatinine-13C3-d3 as internal standard measured with a SCIEX QTRAP 6500. Limits of detection and quantitation were determined on the equivalent of 3 µL dried blood spot extractions.

Results

We demonstrate a strong correlation between venous and capillary (DBS) creatinine values when the creatinine was less than 1.5 mg/dl. There was a small negative bias of -0.1 mg/dL for samples less than 1.5 mg/dL. When the Cr was greater than 1.5 mg/dl we observed a larger negative bias of -0.7 mg/dL in capillary specimens (DBS).

Conclusion

The study established that remote (home) dried blood spot testing (DBS) is a logistically possible method of monitoring both creatinine and immunosuppression levels on the same card when the expected creatinine concentration is less than 1.5 mg/dL. Detecting sudden increases in creatinine may result in more immediate actions prolonging the life of the graft. Eliminating barriers to timely lab draws may improve adherence, decrease costs, and improve overall quality of life. Results greater than 1.5 mg/dl should be confirmed with venous plasma method. Further investigation is on-going to improve the method’s accuracy at high creatinine concentrations.
1. Dickerson, J.A.; Sinkey, M.; Jacot, K.; Stack, J.; Sadilkova, K.; Law, Y.M.; Jack, R.M. Tacrolimus and sirolimus in capillary dried blood spots allows for remote monitoring. Ped Trans. 2015, 19(1): 101-6.