Can rheumatoid arthritis cause blood tests that resemble lupus?

Question

Hello doctor,

I am 51 years old and suffer from rheumatoid arthritis. According to my rheumatologist, one of my blood tests indicated results that resemble lupus, which scares me because I am now worried about possibly having lupus alongside my RA.

My joints are definitely causing issues, but I do not seem to have all the symptoms of lupus that I have read about. Can rheumatoid arthritis cause such readings in blood tests?

Please advise.

Answer 1

Hello,

Welcome to icliniq.com.

I understand your concerns.

If the ANA (antinuclear antibody) test came back positive, you can rest assured that this test is not specific for lupus; it can be positive in up to 30% of rheumatoid arthritis cases and usually does not indicate much beyond secondary ocular or oral dryness.

However, we will need to conduct more specific tests, such as anti-dsDNA (double-stranded DNA), anti-Smith, and a 24-hour urine protein analysis, to rule out lupus, as there is still a possibility of overlap between lupus and rheumatoid arthritis.

Even if we determine that this is an overlap syndrome, or if lupus presents itself with a rheumatoid arthritis-like pattern, if the only system affected is the musculoskeletal system, the management will essentially be the same. There is no need to worry.

Just complete your workup, and regardless of whether this is lupus overlapping with rheumatoid arthritis or simply rheumatoid arthritis with a positive ANA test, there is nothing we cannot manage. The treatment plan will remain the same until a definitive diagnosis is confirmed, with follow-up scheduled after lab results are received.

Hope the above information is helpful.

Best wishes.