Bloods tests false positive? Help!

[epedder]

Hiya! I have been dealing with various lupus like symptoms for over 3 years, and have been passed to countless doctors. I was recently referred to a rheumatologist after a 7 month wait, and lupus bloods were done for the first time(!). The letter I got containing my results says this in the summary, and I was wondering if anyone knows why this was a false positive and what this means? I’m very confused as I have many of the classic symptoms including Raynauds, malar rash, kidney problems, sun sensitivity rash, chronic fatigue and joint and muscle pain, to name a few! Any help appreciated

[PMRpro]

As far as the test is concerned, they found a positive result using the standard test but when they used the high sensitivity Crithidia test it was negative - so the standard test was a "false positive

ltd.aruplab.com/Tests/Pub/2...

where they say

"Positivity for anti-double stranded DNA (anti-dsDNA) IgG antibody is a diagnostic criterion of systemic lupus erythematosus (SLE). The presence of the anti-dsDNA IgG antibody is identified by IFA titer (Crithidia luciliae indirect fluorescent test [CLIFT]). CLIFT is highly specific for SLE with a sensitivity of 50-60 percent.

Some patients with early or inactive SLE may be positive for anti-dsDNA IgG by ELISA but negative by CLIFT. If the CLIFT result is negative but the patient has a positive ELISA and clinical suspicion remains, consider antinuclear antibody (ANA) testing by IFA."

Many of the symptoms are common to other autoimmune disorders - and the rheumy seems to think you have a post-viral syndrome of some sort.

[epedder in reply to PMRpro]

Thank you! I have been trying to get some solid answers for so long I get frustrated when it’s not clear! Thank you for helping

[PMRpro in reply to epedder]

My pleasure! It is all too easy to imagine that lab tests are clear and unambiguous - sometimes they are, all too often they aren't. In autoimmune disorders in particular the picture is very complicated and they are looking at a range of tests and trying to identify patterns,

All the best.

[Hidden]

As Pro says many autoimmune diseases cause these symptoms but as far as I’m aware ME/ CFS isn’t classed as autoimmune and many are misdiagnosed with ME, Fibromyalgia or FND when they actually have a connective tissue disease that presents less classically.

These boxes so many of us don’t quite fit - but also do fit somewhat - don’t take into consideration that we humans are extremely complex and neither we, nor these diseases, always fit into boxes.

I would say that if CFS doesn’t feel like a good fit to you then you might try looking at Lupus related diseases such as Sjögren’s. This is a good link and maybe shows why it’s often misdiagnosed as CFS/ ME. info.sjogrens.org/conquerin...

[PMRpro in reply to Hidden]

Emerging evidence says that at least a subset of ME is a/i

sciencedirect.com/science/a...

[Hidden in reply to PMRpro]

Such an interesting link thanks Pro - I will share it with a couple of friends with ME.