Changing antibodies

[Kikime]

Two years ago I was diagnosed with MCTD . My ANA was positive , alongside my RNP. I had the panel retested, and Anti-SM is now positive alongside RNP and ANA. Does anyone know why?

[whisperit]

According to the Johns Hopkins Lupus centre website, anti-Smith (SM) is "found almost exclusively in people with lupus" but doesn't seem to correlate with either lupus renal disease or disease flares. hopkinslupus.org/lupus-test...

I'm not sure that it is considered diagnostic of lupus, however, as anti-SM alone is not sufficient for a lupus diagnosis, nor does it seem to indicate a particular treatment course academic.oup.com/rheumatolo...

Sorry I can't offer anything more definitive x

[Kikime in reply to whisperit]

Thank you for your help. I will call my doctor tomorrow to get some clarity .