Blood samples obtained by finger-stick (capillary blood) have become routine for monitoring blood glucose levels in diabetics. Similarly, capillary blood is often used for clinical testing in pediatric patients. Use of capillary blood for clinical testing has been limited by methods which entail several preparation steps which require a significant volume of blood to produce the final testing component. TMS BioScience utilizes cutting edge mass spectrometry technology for monitoring transplant medications which does not require extensive sample preparation and, thus, can use very low volumes of whole blood. This process has been shown to be feasible and reliable by the University of Manchester transplant program. In conjunction with the Tulane Abdominal Transplant Institute, TMS BioScience sponsored a study to demonstrate the accuracy and reliability of using finger-stick small volume blood samples for monitoring immunosuppressant drug levels. As can be reviewed on the website, it is evident that capillary blood obtained by finger-stick is interchangeable with venous blood samples in monitoring transplant patients’ immunosuppressant levels. The difference in results of traditional venous large volume blood samples vs. small volume capillary blood samples is negligible with less 3% difference at the greatest average deviation and generally ≤ 1% for drug levels by tandem mass spectrometry testing. Based on this evidence, in conjunction with additional instrument implementation, TMS BioScience pioneered HomeTrak for monitoring transplant patients. HomeTrak provides accurate immunosuppressant drug levels to guide dosing along with essential kidney and liver function data all from a small volume blood sample obtained at-home by finger-stick performed by the patient. These samples are mailed to TMS BioScience laboratory and results are promptly reported to the attending transplant team for guidance in maintaining post-transplant therapy.
Multiple assays performed on simultaneously acquired blood samples from individual study subjects show very high correlation in side-by-side comparison of immunosuppressant levels as determined by tandem mass spectrometry in the TMS BioScience laboratory. The results are clinically equivalent in determining dosage for maintenance immunosuppression.