Routine lab tests are not reliable for diagnosing Long COVID, according to a new study. The research found that no clinical lab values could serve as biomarkers, highlighting the need to focus on symptoms for diagnosis.
A new study found that most routine laboratory tests are not reliable for diagnosing Long COVID, also known as Post-Acute Sequelae of SARS-CoV-2 infection (PASC).
The study, published in Annals of Internal Medicine, found no reliable biomarker among 25 routine clinical laboratory values for prior infection, PASC, or specific types of PASC clusters. This suggests none of these routine labs can serve as a clinically useful biomarker of PASC.
“Our study shows patients can have severe Long COVID with normal lab results. This suggests doctors should not focus on the results of blood panels to diagnose Long COVID but should focus more on symptoms and ways to help patients get relief by treating their symptoms,” said the study’s first author, Kristine Erlandson, MD, a professor in the Division of Infectious Diseases at the University of Colorado Anschutz Medical Campus.
Seven percent of all adults in the U.S., nearly 18 million people, currently have long COVID, according to the Agency for Healthcare Research and Quality’s Medical Expenditure Panel Survey.
“Our challenge is to discover biomarkers that can help us quickly and accurately diagnose long COVID to ensure people struggling with this disease receive the most appropriate care as soon as possible,” said David Goff, MD, PhD, director for the Division of Cardiovascular Sciences at the NIH’s National Heart, Lung, and Blood Institute. “Long COVID symptoms can prevent someone from returning to work or school, and may even make everyday tasks a burden, so the ability for rapid diagnosis is key.”
Large-Scale Study and Findings
This study was funded by the National Institutes of Health’s (NIH) Researching COVID to Enhance Recovery (RECOVER) Initiative. The RECOVER initiative includes multiple research studies that involve thousands of participants from across the country. In Colorado, these studies take place at the Colorado Clinical and Translational Sciences Institute (CCTSI) at CU Anschutz.
To investigate clinical laboratory markers of SARS-CoV-2 and PASC, the researchers examined data from nearly 10,000 adults with and without SARS-CoV-2 infection. The researchers recruited from over 80 enrolling sites across 33 U.S. states plus Washington, DC, and Puerto Rico, making it one of the largest and most diverse studies of its kind.
The study compared results in several ways: between participants with and without prior SARS-CoV-2 infection at six months after infection, between participants with and without PASC, and between participants with each of the four most common PASC symptom phenotypes and those unlikely to have PASC.
Modest Differences, But No Clear Biomarkers
They found participants with prior SARS-CoV-2 infection showed modest increases in HbA1c (a marker of long-term blood sugar levels) and urinary albumin-to-creatinine ratio (uACR), along with small decreases in platelet counts.
“While these differences are statistically significant, these associations are generally small and not reliable enough to serve as diagnostic biomarkers for PASC,” Erlandson says.
The researchers suggest this data shows the complexity of PASC as a condition that may involve multiple physiological pathways beyond simple laboratory markers, such as those for inflammation, anemia, or other markers.
“Long COVID has been very elusive; numerous possible symptoms, no definite cause, and no clear treatment. We hear from patients that their concerns are dismissed by providers because their lab tests are normal. In this study, even the exhaustive list of routine blood tests could not help in making a PASC diagnosis. This is an important observation in PASC research as prior smaller studies showed inconsistent abnormalities in some blood tests. Until a reliable biomarker is found, the best diagnostic modality for PASC remains the old-fashioned history taking and clinical assessment,” Grace McComsey, MD, senior author of the paper, professor and vice dean of clinical and translational research at Case Western Reserve University.
The researchers also note that it’s still important to do routine laboratory tests to rule out other conditions during the process of diagnosing PASC.
Reference: “Differentiation of Prior SARS-CoV-2 Infection and Postacute Sequelae by Standard Clinical Laboratory Measurements in the RECOVER Cohort” by Kristine M. Erlandson, Linda N. Geng, Caitlin A. Selvaggi, Tanayott Thaweethai, Peter Chen, Nathan B. Erdmann, Jason D. Goldman, Timothy J. Henrich, Mady Hornig, Elizabeth W. Karlson, Stuart D. Katz, C. Kim, Sushma K. Cribbs, Adeyinka O. Laiyemo, Rebecca Letts, Janet Y. Lin, Jai Marathe, Sairam Parthasarathy, Thomas F. Patterson, Brittany D. Taylor, Elizabeth R. Duffy, Monika Haack, Boris Julg, Gabrielle Maranga, Carla Hernandez, Nora G. Singer, Jenny Han, Priscilla Pemu, Hassan Brim, Hassan Ashktorab, Alexander W. Charney, Juan Wisnivesky, Jenny J. Lin, Helen Y. Chu, Minjoung Go, Upinder Singh, Emily B. Levitan, Paul A. Goepfert, Janko Ž. Nikolich, Harvey Hsu, Michael J. Peluso, J. Daniel Kelly, Megumi J. Okumura, Valerie J. Flaherman, John G. Quigley, Jerry A. Krishnan, Mary Beth Scholand, Rachel Hess, Torri D. Metz, Maged M. Costantine, Dwight J. Rouse, Barbara S. Taylor, Mark P. Goldberg, Gailen D. Marshall, Jeremy Wood, David Warren, Leora Horwitz, Andrea S. Foulkes and Grace A. McComsey, 13 August 2024, Annals of Internal Medicine.
DOI: 10.7326/M24-0737
News
World First: Stem Cell Transplant Restores Vision in Multiple People
A radical stem cell transplant has significantly improved the blurry vision of three people with severe damage to their cornea. The clinical trial, which took place in Japan, is the first of its kind in the world, [...]
Clinical Trial: Mushroom Supplement May Halt Prostate Cancer Growth
The bidirectional research examines both laboratory findings and human clinical trial data, revealing that the medicinal use of white button mushrooms reduces the type of cells that suppress the immune system and facilitate the [...]
Scientists propose drug-free method to combat antibiotic-resistant bacteria
Recent estimates indicate that deadly antibiotic-resistant infections will rapidly escalate over the next quarter century. More than 1 million people died from drug-resistant infections each year from 1990 to 2021, a recent study reported, with [...]
New study shows how salmonella tricks gut defenses to cause infection
A new UC Davis Health study has uncovered how Salmonella bacteria, a major cause of food poisoning, can invade the gut even when protective bacteria are present. The research, published in the Proceedings of the National Academy [...]
Chlamydia vaccine shows early promise in mice
An experimental vaccine has shown promise in protecting against the sexually transmitted disease chlamydia, researchers report. Lab mice given the vaccine were able to rapidly clear subsequent chlamydia infections, and were less likely to [...]
Contradictory Discovery: Our Innate Immune System May Fuel Cancer Development
MSK researchers discovered that the innate immune system’s chronic activation due to issues in the Mre11 complex can lead to cancer, highlighting new therapeutic targets. In addition to defending against pathogens, the body’s innate [...]
New study links circadian gene variants to winter depression
Findings suggest that PER3 gene variants prevent adrenal adaptation to winter daylight, leading to serotonin disruption and depression-like behaviors. A recent study in Nature Metabolism used humanized mice with modified PERIOD3 gene variants (P415A and H417R) [...]
Quantum Leap for MRI: Atomic Sensors Unlock New Imaging Potential
New atomic sensor technology enhances MRI quality control by tracking hyperpolarized molecules in real-time, with potential benefits for various scientific fields. Magnetic resonance imaging (MRI) is a fundamental tool in modern medicine, offering detailed [...]
MethylGPT unlocks DNA secrets for age and disease prediction
By harnessing advanced AI, MethylGPT decodes DNA methylation with unprecedented accuracy, offering new paths for age prediction, disease diagnosis, and personalized health interventions. In a recent study posted to the bioRxiv preprint* server, researchers developed a [...]
“Astonishing” – Scientists Unveil First Blueprint of the Most Complex Molecular Machine in Human Biology
Researchers unveil the inner mechanisms of the most intricate and complex molecular machine in human biology. Scientists at the Centre for Genomic Regulation (CRG) in Barcelona have developed the first comprehensive blueprint of the [...]
Breakthrough research reveals how to target malignant DNA in aggressive cancers
Scientists have discovered a way to target elusive circular fragments of DNA that drive the survival of some of the most aggressive cancers, paving the way for future treatments. In three groundbreaking papers published [...]
How bacteria trigger colon cancer
In a recent study published in Nature, scientists used murine models to investigate how certain bacteria, such as Escherichia coli strains that contain a polyketide synthase (pks) island encoding enzymes that produce colibactin genotoxin, could increase the [...]
Nanoparticles designed to trap and neutralise large amounts of SARS-CoV2
(Nanowerk News) Researchers from the IBB-UAB have developed a new class of nanostructures capable of trapping and neutralising large quantities of the SARS-CoV2 virus particles, both in liquid solutions and on the surface of [...]
Nanodiscs: What Are They and How Are They Shaping the Future of Medicine?
Nanodiscs are synthetic phospholipid particles with a distinct morphology and size that enhance their efficiency in drug delivery applications.1 First developed by Sligar et al. in the early 2000s, these model membrane systems measure around 10 [...]
New Discovery Reveals How Ovarian Cancer Starves Immune Cells
Researchers discovered that ovarian tumors hinder T cells’ energy supply by trapping a key protein, blocking lipid uptake. A new approach to reprogram T cells could enhance immunotherapy for aggressive cancers. Researchers at Weill Cornell [...]
Innovative Drug-Design Strategies to Overcome Antibacterial Resistance
Antibacterial resistance occurs when antibiotics fail to treat bacterial infections. This incidence is considered one of the top global health threats, stemming from the misuse or overuse of antibiotics in humans and animals.1 The [...]
