Researchers in Libya compared two blood tests used to diagnose rheumatoid arthritis, a disease where the body’s immune system attacks joints. They tested 70 people with arthritis and 70 healthy people. One test, called anti-CCP, correctly identified arthritis in about 79% of patients and never gave false alarms in healthy people. The older test, called rheumatoid factor, only caught 64% of cases and sometimes incorrectly flagged healthy people as having arthritis. This study suggests doctors should use the anti-CCP test more often because it’s more accurate at finding who really has the disease.

The Quick Take

  • What they studied: Whether a newer blood test (anti-CCP) is better than an older blood test (rheumatoid factor) at correctly identifying people who have rheumatoid arthritis
  • Who participated: 140 people total: 70 with confirmed rheumatoid arthritis and 70 healthy people without the disease, all from Libya, matched by age and sex
  • Key finding: The anti-CCP test correctly identified arthritis in 79% of patients and never gave false positives in healthy people, while the older rheumatoid factor test only caught 64% of cases and sometimes incorrectly flagged healthy people
  • What it means for you: If you’re being tested for rheumatoid arthritis, asking your doctor for the anti-CCP test may give you a more accurate answer about whether you have the disease. However, this study was done in Libya, so results may vary in other populations, and you should discuss test options with your healthcare provider

The Research Details

This was a case-control study, which is like comparing two groups side-by-side. Researchers took blood samples from 70 people already diagnosed with rheumatoid arthritis and 70 healthy people who didn’t have the disease. They made sure both groups were similar in age and sex so the comparison would be fair. Then they measured specific proteins in the blood (anti-CCP and rheumatoid factor) and other markers of inflammation like CRP and ESR. They also collected information about each person’s symptoms, family history, and other health conditions.

This type of study design is useful for figuring out which tests work best at telling the difference between people who have a disease and people who don’t. By comparing the same blood tests in both groups, researchers can see which test is more accurate. This matters because getting the right diagnosis quickly helps people start treatment sooner, which can prevent permanent joint damage from arthritis.

The study had equal numbers of patients and controls, which is good for fair comparison. The researchers measured multiple blood markers, not just one, which gives a more complete picture. However, this study only included people from Libya, so the results might not apply equally to all populations around the world. The study was published in a peer-reviewed journal, meaning other experts reviewed the work before publication.

What the Results Show

The anti-CCP test was positive in 79% of people with rheumatoid arthritis but was negative in all 70 healthy controls. This means it correctly identified most arthritis cases without any false alarms in healthy people. In comparison, the rheumatoid factor test was positive in 64% of arthritis patients but also showed up in some healthy people, meaning it gave false alarms. The anti-CCP test was also more strongly connected to signs of active disease, like swollen and tender joints, high inflammation markers (CRP and ESR), and higher disease activity scores. People with positive anti-CCP tests were more likely to be female, have a family history of arthritis, have lower vitamin D levels, and have other autoimmune conditions like type 1 diabetes.

The study found that anti-CCP positivity was linked to several blood cell changes, including higher neutrophil-to-lymphocyte ratios (a sign of inflammation), higher platelet counts, and changes in red blood cell size. Interestingly, people who had received COVID-19 vaccinations and those with a history of smoking also showed associations with anti-CCP positivity. These secondary findings suggest that anti-CCP is connected to broader immune system changes in arthritis patients, not just the presence of the disease itself.

Previous research has suggested that anti-CCP is more specific than rheumatoid factor, meaning it’s better at correctly identifying people who actually have arthritis. This study confirms those earlier findings in a Libyan population. The anti-CCP test can sometimes detect arthritis years before symptoms appear, which is valuable for early intervention. The rheumatoid factor test, while useful, has been known to give false positives in other conditions and in some healthy people, which this study also confirmed.

This study only included people from Libya, so the results might not apply the same way to other populations with different genetic backgrounds or environmental factors. The study was relatively small with 140 total participants. The researchers didn’t follow patients over time to see how the test results changed with treatment, so we don’t know how useful these tests are for monitoring disease progress. The study didn’t include people with other diseases that might also cause positive results, so we can’t fully compare how specific the tests are in real-world situations.

The Bottom Line

If you’re being evaluated for rheumatoid arthritis, ask your doctor about getting the anti-CCP test as part of your diagnostic workup. This test appears to be more accurate than the older rheumatoid factor test alone. However, no single blood test can diagnose arthritis by itself—doctors use blood tests along with physical exams, imaging, and symptom history. If you already have arthritis, discussing anti-CCP testing with your rheumatologist may help with monitoring your disease. Confidence level: Moderate, as this study was done in one specific population.

This research is most relevant for people being evaluated for rheumatoid arthritis, especially those with joint pain and swelling. Rheumatologists and primary care doctors should consider this when choosing which blood tests to order. People with a family history of arthritis might benefit from knowing about this more accurate test. This is less relevant for people without joint symptoms or those already diagnosed and stable on treatment, though it may still be useful for monitoring.

Blood test results come back within days, so you’ll know quickly if the anti-CCP test is positive or negative. However, a positive test doesn’t mean you’ll definitely develop arthritis symptoms—some people have the antibodies for years before symptoms appear. If you do have arthritis and start treatment based on these test results, it typically takes 6-12 weeks to see improvement in joint pain and swelling.

Want to Apply This Research?

  • If you have rheumatoid arthritis, track your anti-CCP test results and dates in the app. Record the numerical value (not just positive/negative) and note any changes in your disease activity, joint pain scores (0-10 scale), and medication adjustments around the time of testing. This helps you and your doctor see patterns over time.
  • Use the app to set reminders for regular blood work appointments to monitor your anti-CCP levels and other inflammation markers. Create a symptom log that you can share with your doctor at each test appointment, noting which joints hurt most, morning stiffness duration, and how your symptoms correlate with test results.
  • Establish a baseline by recording your initial anti-CCP result and disease activity level. Then track results every 3-6 months (or as recommended by your doctor) to see if your levels are trending up or down with your current treatment. Compare these trends with your symptom diary to understand how well your treatment is working and whether adjustments might help.

This research summary is for educational purposes only and should not replace professional medical advice. The study was conducted in Libya and results may vary in other populations. If you have symptoms of rheumatoid arthritis or are concerned about your joint health, consult with a qualified healthcare provider or rheumatologist. Blood tests are one tool among many used to diagnose arthritis—they should be interpreted by a medical professional in the context of your complete medical history, physical examination, and imaging studies. Do not make treatment decisions based solely on this summary.