Hey @bayhorse - here’s my understanding of UCTD based on a pretty extensive review of available evidence (Medscape, UpToDate, and many many peer reviewed journal articles. I am a healthcare provider (but I do not work in rheumatology). Basically, a whole bunch of rheumatologists from around the world have come together and put together “classification criteria” for many rheumatologic (autoimmune) diseases. The classification criteria are strict and are used to include (or exclude) people from research studies. In real life (not research studies), individual rheumatologists have to use their best judgment about the patient’s overall condition/picture to determine if a diagnosis seems right (like lupus).

I’m both over-simplifying (and being a little tongue-in-cheek), but UCTD typically looks like a “mild” version of lupus, or RA, or Sjögren’s (or a combo of those). I think that the “mild” mostly refers to not often having severe damage to internal organs (like the kidneys) and not to the person’s symptoms. Unfortunately, that international group of rheumatologists has NOT gotten together to clearly define either “classification” criteria (for research) or diagnostic criteria (for real-world providers). Most providers and researchers use this definition of UCTD: positive ANA sustained over 3 years plus at least one symptom of a “defined” connective tissue disease (lupus, RA, Sjögren’s, etc.). Then, over the next 3-5 (or up to 15) years, one of three things usually happens: 1) symptoms go away completely 2) symptoms stay steady or 3) the person accumulates enough symptoms or new auto-antibodies to update the diagnosis to lupus or RA or Sjögren’s or MCTD, etc.

I see that you initially posted in 2018. If you have developed new symptoms or new auto-antibodies, that might be why your provider feels you have tipped into a specific category.