Lab Test Results

[pj]

I was just wondering if anyone else has had positive ANA and positive antiproteinase 3 (pr3) tests with MS. I have had MS for 12 years and recently these other tests have come back positive for Sjogrens SS-b 2.0 and the pr3 at 6.7. I have had raynauds syndrome in my toes and fingers for about a year, also some symptoms that have not really been the norm for my MS, which is what prompted the blood work. I can't seem to find any info on pr3 in any diseases except Wegeners and a few vascular diseases. My ANCA titers show <1:20 which would be negative, but my pr3 is positive, so my question is how could I be neg ANCA, but pos pr3. Any help on this would be great, because I am about researched out!

[Redwings]

Hi pj:
To answer (sort of) your questions, there are a couple of underlying issues that have to be considered. The first is that people aren’t generally screened for vascular diseases unless there are indications that they may have one. MS isn’t a vascular disease (although there are vascular components), so people with MS, or who are being worked up for MS, generally aren't screened for vascular diseases without suspicion, so may not be able to respond to your question (they may not even know whether they were screened). As in your own case, you weren’t tested until you had indications of something going on that isn’t typical of MS.

Second, there’s a theory (with some good evidence) that the underlying disease is "autoimmunity," and all of the various autoimmune conditions are just “flavors” of it. That theory explains why people who have one autoimmune condition are likely to also have at least one other. There’s evidence that the same genes are associated with several autoimmune conditions. The theory also explains why some antibodies or findings that are typical of one condition can “cross over” and be found in other conditions. I’ll get back to that in a minute.

ANA is somewhat nonspecific and can be abnormal in several conditions. ANA can also be elevated in people who are known to be perfectly healthy. Sometimes it can be abnormal without a full understanding of why. My ANA is not only abnormal, but sky high when I’m not taking immunosuppressants, and it’s my only abnormal antibody. (I’ll spare you the rest of the story, but as it turned out, I have a demyelinating disease that isn’t MS.)

As for your other lab tests, maybe it will clear things up for you a bit to know that PR3 is a form of ANCA. So it’s possible for your PR3 to be abnormal/equivocal while other ANCA tests are normal. And here’s where that “crossover” of antibodies becomes important. PR3 can also be abnormal in other conditions, including rheumatoid arthritis and ulcerative colitis/Crohn’s disease and peripheral neuropathy. [Another example of autoimmune disease crossover is that the other approved use of Tysabri besides MS is for Crohn’s disease. Also, BG-12 (dimethyl fumarate), which is in the pipeline as an MS treatment, has been investigated as a treatment for rheumatoid arthritis and is used in Europe as a treatment for plaque psoriasis.]

So if you research PR3 in those other diseases, you might get some answers for your questions. Or it might raise more new questions than answers because some of this autoimmunity stuff can be nonspecific, and the crossover can make it unclear about which disease(s) the antibodies indicate.

Ultimately, your rheumatologist will have to figure it all out. That’s why specialists get paid the big buck$.

[pj]

Thank you so much redwing. Wow that answers alot of my questions. Sometimes all of it becomes so confusing, it gets frustrating. I have a hard time anymore trying to figure out what symptoms come from what. I' gonna stick with autoimmunity period. I appreciate your help!!! So tricky, all of these diseases.