How do you diagnose sjogrens syndrome for sure?

See below. You must have symptoms plus antibodies or a minor salivary biopsy plus symptoms.
Bx and lab. I do minor salivary gland bx, and really heavily on lab tests, looking for the presence of ss-a and ss-b autoantibodies. Almost 50% of sjogren's patients have a positive rf. Eelvations of gammaglobulins are common, especially IgG and igm. There is some heredebiity to this condition, albeit weaker than many forms of arthritis.