Early Seropositivity in Sjogren's Syndrome

Autoimmunity diagram found here. 

I've read in a variety of sources that many times the symptoms of Sjogren's syndrome can be present for years before the level of auto antibodies is detectable on a blood test. But I found the results of this study interesting in that it concluded:

...Autoantibodies are found up to 18-20 years before diagnosis of pSS, but we cannot exclude even earlier seropositivity, as most patients were positive in the earliest analysed sample.

Twenty years BEFORE.

Abstract
OBJECTIVE: Autoantibodies are highly characteristic of primary Sjögren's syndrome (pSS) and represent important tools to study its pathogenesis. Nonetheless, thus far no systematic investigations have assessed the presence of autoantibodies before diagnosis. We analysed how early and in which order these appear, how predictive they are for pSS and if they identify disease subsets.

You can read the complete abstract of this study published in the American College of Rheumatology's journal Arthritis & Rheumatology here.