Common diabetes test could miss the condition in people with sickle cell trait

Breaking research featured at ADLM 2026 meeting

ANAHEIM, Calif., July 28, 2026 /PRNewswire/ -- People with sickle cell trait — those who have one sickle cell gene but do not experience sickle cell disease — may need specific laboratory monitoring for blood sugar in order to detect and treat pre-diabetes and diabetes, researchers in Ghana have found.

Immunoturbidimetry, a common laboratory assay used to measure the concentration of specific proteins in a sample, significantly underestimated hemoglobin A1c (HbA1c) blood sugar levels in people with sickle cell trait compared to high-performance liquid chromatography (HPLC), a technique that separates and quantifies specific components in liquids, investigators found. Relying on immunoturbidimetry therefore could lead to an underclassification of pre-diabetes and failure to detect diabetes in these individuals. The study was presented today at ADLM 2026 in Anaheim, California.

"We have a high prevalence of sickle cell disease — about 2% of all newborns — and sickle cell trait in about 30% of the Ghanaian population. However, the influence of hemoglobin variants on HbA1c testing hasn't been well characterized in our region," said lead study author Dr. Elikem Kumahor, a specialist laboratory physician at Korle Bu Teaching Hospital in Accra, Ghana. "Our study indicates that relying on immunoassays alone likely contributes to a significant underdiagnosis of diabetes. We recommend adopting other laboratory methods that factor in hemoglobin variants, like HPLC or mandatory reflex testing algorithms, for accurate diabetes assessments in high-risk populations."

Dr. Kumahor and colleagues conducted a retrospective study using 1,283 consecutive HbA1c tests from patients ages 18 and older at a tertiary hospital in Accra in January and February 2026. Initial measurements were performed on an HPLC platform that automatically detects hemoglobin variants. Then, 256 samples with suspected variants were reanalyzed using immunoturbidimetric assays. Investigators confirmed the sickle cell trait using hemoglobin electrophoresis, a technique that separates hemoglobin protein variants based on their size and charge.

They categorized 1,027 patients as HbAA (normal) and 198 as HbAS (having the sickle cell trait). About 58 individuals with other hemoglobin variants were excluded from further study. Investigators then calculated the mean HbA1c differences between the two laboratory methods and compared the classification of patients to either pre-diabetes (HbA1c 5.7%) or diabetes (HbA1c 6.5%) categories.

Among the total samples screened, hemoglobin variants were detected in 256 people (20% of the sample), with HbAS confirmed in 198 (15.4%) of the total. In the HbAA group, mean HbA1c by immunoassay and HPLC showed minimal bias. However, in the HbAS group, the immunoassay significantly underestimated HbA1c compared to HPLC (5.1% vs. 5.9%).

Using immunoassay, only 11.1% (22 of the 198) HbAS participants were classified as pre-diabetic, compared to 34.5% (68 of the 198) using HPLC. Additionally, 4% (8 of the 198) of HbAS individuals met the diabetes criteria using HPLC, while none were classified as diabetic using immunoassay.

"From this preliminary study, we noted that HbA1c results measured in participants carrying the sickle cell trait were significantly decreased compared to participants with normal hemoglobin when results from HPLC were compared to results from immunoturbidimetry," Dr. Kumahor said.

"HbA1c testing is currently being accessed by clinicians as a non-fasting glucose test for the diagnosis and monitoring of diabetes; however, its clinical utility may not be universally applicable in regions with a high prevalence of hemoglobin variants," he added, noting that people who are diabetic or who are routinely screened for diabetes should have their hemoglobin genotype tested. "Understanding the limitations of testing, especially with immunoassays, has the benefit of guiding protocols and policies on the use of this testing in Ghana and other areas of West Africa."

Session information

ADLM 2026 registration is free for members of the media. Reporters can register online here: https://xpressreg.net/register/adlm0726/media/landing.asp

Abstract A-150: The hidden burden of diabetes mellitus: Impact of sickle cell trait on HbA1c measurement by immunoassay vs. HPLC in a West African Population will be presented during:

Scientific poster session
Tuesday, July 28
9:30 a.m. – 5 p.m. (presenting authors in attendance from 1:30 – 2:30 p.m.)

The session will take place in the Poster Hall on the Expo show floor of the Anaheim Convention Center in Anaheim, California.

About ADLM 2026
ADLM 2026 offers 5 days packed with opportunities to learn about exciting science from July 26-30 in Anaheim, California. Plenary sessions will explore landmark diabetes studies, the role of laboratory medicine in keeping astronauts healthy, the connection between Alzheimer's and Down syndrome, advances in cervical cancer screening, and the search for new cancer biomarkers using mass spectrometry.

At the ADLM 2026 Clinical Lab Expo, more than 700 exhibitors will fill the show floor of the Anaheim Convention Center, with displays of the latest diagnostic technology, including but not limited to artificial intelligence, point-of-care, and automation.

About the Association for Diagnostics & Laboratory Medicine (ADLM)
Dedicated to achieving better health for all through laboratory medicine, ADLM unites more than 70,000 clinical laboratory professionals, physicians, research scientists, and business leaders from 110 countries around the world. Our community is at the forefront of laboratory medicine's diverse subdisciplines, including clinical chemistry, molecular diagnostics, mass spectrometry, clinical microbiology, and data science, and is comprised of individuals holding the spectrum of lab-related professional degrees, certifications, and credentials. Since 1948, ADLM has championed the advancement of laboratory medicine by fostering scientific collaboration, knowledge sharing, and the development of innovative solutions that enhance health outcomes. For more information, visit www.myadlm.org.

Christine DeLong
ADLM
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Bill Malone
ADLM
Senior Director, Strategic Communications
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SOURCE Association for Diagnostics & Laboratory Medicine (ADLM)