Mayo Clinic Lab Director explains how the ELF Test supports liver fibrosis patient management with a simple blood draw

Hello, I'm Nikola Baumann, and I am the Vice Chair of Quality in the Department of Laboratory Medicine and Pathology at the Mayo Clinic. I also serve as the CLIA Laboratory Director and the Director of the Central Clinical Lab and Central Processing Area.

It's very important to have tests such as ELF, the Enhanced Liver Fibrosis Test, available in the core laboratory and also available in reference laboratories, because these tests are so important in the management of MASLD, or metabolic dysfunction-associated steatotic liver disease. These patients are also worked up through elastography, but we know that that's not always available to patients. They're often referred to hepatologists, which is also a specialty area, and there are long waits for those appointments. So having information available to providers through something as simple as a blood collection or a blood draw is highly valuable for these patients and really improves patient care.

Long-term patient outcomes could really be improved by having accessible laboratory testing for MASLD. We know that in the United States, there are 80 to 100 million people impacted by this disease, and yet they're not always being diagnosed. They're being missed, and sometimes they're not even being screened during the visits where they should be. So again, having a patient come in, and they can even get a blood draw before their appointment, means they can have that information available. Having that information as a laboratory test also means that we're ensuring accuracy, reliability and reproducibility over time. That result is in the electronic medical record, and it can be acted upon.

The other important thing about MASLD is that while it's progressive, it's also reversible. So the earlier we can detect and diagnose this disease, the earlier patients can take the necessary interventions, whether that's a medication, a lifestyle change, more regular monitoring, coming in more frequently or seeing a specialist. All of those will improve outcomes for these patients. It's really important that the earlier we can detect this disease and give prognosis to these patients, the more providers and patients can make the right decisions.

Bringing a novel diagnostic into the clinical laboratory is not trivial. We really have two options in the clinical laboratory. We have laboratory-developed tests, in which the burden of analytical validity and clinical validity both fall upon the laboratory. Or we have, in the U.S., FDA-authorized tests, where the clinical validity is established by the manufacturer of the assay and the burden on the clinical lab is ensuring analytical validity. FDA-approved tests are easier to implement, there is less regulatory burden, and they are usually easier to maintain because we have manufacturer specifications to work from.

As a lab director, when I'm thinking about a laboratory test, I'm thinking that I need the physician to be able to easily order it. I want to know that in my lab, I'm providing accurate, reproducible results, with very little variability over time between reagent lots, so stability of the assay is important. And then I need to know that the interpretive reporting we're providing is valuable to both the physician and the patient.

Patients often see their test results before the provider does, so those three steps are really important. First is analytical validity: I need to know that the test is accurate and reliable, and that decisions can be made from it. Then there is integration into the electronic health record, so that the test is orderable by a physician, as well as consideration of the reporting.

Finally, there is collaboration with our healthcare providers, so that we are talking to hepatologists and primary care physicians, telling them what testing is available, how they can get it and how they can use those results to improve patient care.

I think engaging physicians in the process of developing and delivering novel diagnostic tests is really important. We're a team. Even though I always think of the laboratory as sometimes the black box that patients don't see and providers often don't see, we are a healthcare team providing care for the patient.

My philosophy is: make good friends with your hepatologists and your primary care physicians. When we were launching the ELF test, I sat down with our hepatologist who specializes in MASLD, and we developed the interpretive reporting together, thinking about what would be helpful to primary care physicians and what would be helpful for a patient when they saw their own report. And what would trigger (I think this might be the most important point) the right next decision? Whether that's follow-up, monitoring, intervention, a referral or imaging. So making sure that the test report really triggers the right next step for the patient is key to improving patient care.