Question on blood tests

[Dbrock]

I'm going in to see the doctor and am wondering what blood tests I should request.  I have many of the Sjogren's symptoms and have had high CRP levels and high MPO levels in the past.  All other tests (SED rate, ANA, etc.) come back negative.  It's so very frustrating and I'm trying to be patient, but don't want to leave any stone unturned.  Thank you.

[Linda196]

Myeloperoxidase (MPO) can be confusing. High levels with high CRP are usually more of a reference for cardiac risk, not autoimmunity, while MPO deficiency is more indicative of genetic predisposition to autoimmunity, and MPO antibodies can actually be used to diagnose some autoimmunities.

If, when you got your normal ANA results, there was no breakdown to individual antibodies like anti-SSA (Ro) or anti-SSB (La), you could ask for an ENA Panel. It is possible for the overall ANA to be within normal range but some component antibodies to be elevated.

If your doctor or ophthalmologist has access to the novel antibody test for Sjogren's, developed in 2011, it may show positive results even though standard results are negative, but unfortunately it has not been fully accepted by the Rheumatologist Association, and therefore may not be recognised as definitive. http://www.sciencedirect.com/science/article/pii/S1521661612002392

[Dbrock]

Thank you for explaining this.  It's very helpful