Multiple ANA Tests May Be Needed to Diagnose Lupus
New research highlights the potential importance of ordering more than one type of antinuclear antibody (ANA) test when clinicians are screening for lupus. ANAs are a type of antibody that are found in the blood of lupus patients, and ANA blood tests are often used to help diagnose lupus or classify it in research studies. However, previous studies have found different ANA tests can produce different results, leaving clinicians unsure of their value when making a lupus diagnosis.
In the latest study, researchers found that there was a high degree of agreement between the three different ANA blood tests performed: indirect immunofluorescence assay (IFA)1, IFA2 and ANA enzyme-linked immunosorbent assay (ELISA). Particularly at the time of study enrollment, nearly all participants had a positive ANA test result regardless of which ANA test was performed:
- IFA1: 96.1%
- IFA2: 98.3%
- ANA ELISA: 96.6%
Overall, there was more than 91% agreement between the three tests at all study time points. However, there was modest variation between the tests where, as lupus evolved over the five-year study period, there was an observed increase in the number of negative ANA test results. For this reason, the researchers concluded that clinicians should consider performing more than one type of ANA test if initial test results come back negative for a person they suspect has lupus.
This study was led by Lupus Foundation of America Gary S. Gilkeson Career Development Awardee May Choi, MD, MPH. Learn more about Dr. Choi and her research efforts.
“This is the largest multinational study where ANA tests were systematically performed on lupus patients over 5 years of disease from diagnosis. The results help clarify some of the important questions about the ANA test that researchers and clinicians have been wondering about ever since the test was discovered over 60 years ago.” says Dr. May Choi lead study author and Medical-Scientific Advisory Council member with the Lupus Foundation of America.
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