Phosphate levels are associated with a slew of cardiovascular and renal complications, with hyperphosphatemia serving as a direct stimulus to vascular calcification in CKD patients. As phosphate begins to build up, our mineral homeostasis goes off course – resulting in capillaries being clogged and our bones breaking down. Currently, there is no point-of-care method for phosphate detection, with blood analysis being the main clinical diagnostic tool. Other biomarker abnormalities like elevated potassium, FGF23, and PTH are also associated with CKD. A weak kidney may lead to other problems like vascular calcification and bone abnormalities – resulting in serious illness and eventually death. After speaking with nephrologists, many CKD patients are diabetic, so glucose is also a valuable biomarker to detect for patient car
Why is CKD diagnostics so important? Because the dietary changes a patient makes in response to their biomarkers can improve their quality of life and disease course. Having a patient know their potassium level is high may save their life due to the sudden risk of heart attack. But more importantly – as we age, all of our kidneys weaken, and CKD is referred to as the silent killer. Without diagnostics monitoring these biomarkers sudden death and illness will remain high. About 14% of the United States has CKD, that’s over 45 million people, with rates higher in the Mexican-American and African-American communities.
Age-Adjusted Prevalence of CKD Stages 1-4 by Gender 1999-2012
The limits of clinical phosphate detection were further discussed in a meeting with Dr. Rachel Holden (Division of Nephrology, Department of Medicine) and Dr. Michael Adams (former Head of the Department of Biomedical and Molecular Sciences) who spoke to the numerous limitations of blood testing for phosphate detection while strongly supporting our project and the significance it can have in the clinic. According to Dr. Holden, phosphate levels of CKD patients are taken approximately once every 6 weeks, which provide little insight into the state of CKD. She discussed a need for real-time and fast detection of phosphate levels, which is what our project aims to provide. By giving physicians and patients the ability to measure their own phosphate levels quickly, accurately, and continuously, our project can truly make a difference in the lives of CKD patients around the world.
Measuring in vivo levels of phosphate, potassium, FGF23, PTH, and glucose daily will save lives.
Using a minimally invasive microneedle patch on the arm we can take a patient’s interstitial fluid, and with fluorescent binding proteins measure the levels of CKD biomarkers, in our portable fluorometer style device. Our smartphone application may alert a physician and patient of abnormal biomarker levels preventing catastrophe.
Our fluorescent binding protein system is modular and has a high specificity for our biomarkers. And with our custom cysteine coiled-coil anchoring technique, we can easily bind other proteins, to detect other metabolites. We see it as building a doll house, CKD patients use it to build their health.
Webster AC, Nagler EV, Morton RL, Masson P. Chronic Kidney Disease. Lancet Lond Engl. 2017 25;389(10075):1238–52.
Chen TK, Knicely DH, Grams ME. Chronic Kidney Disease Diagnosis and Management: A Review. JAMA. 2019 01;322(13):1294–304.
Centers for Disease Control and Prevention. Age-adjusted prevalence of CKD Stages 1-4 by Gender 1999-2012. Chronic Kidney Disease (CKD) Surveillance Project website. https://nccd.cdc.gov External link. Accessed December 6, 2016.
Centers for Disease Control and Prevention. Age-adjusted prevalence of CKD Stages 1-4 by Race/Ethnicity 1999-2012. Chronic Kidney Disease (CKD) Surveillance Project website. https://nccd.cdc.gov External link. Accessed December 6, 2016.