Causes of Raynaud's phenomenon and the predictive laboratory and capillaroscopy features for the evolution to a definite connective tissue disease.

Abstract

In patients with RP, capillaroscopy is useful for discriminating primary from secondary causes. There are certain capillaroscopy and lab values as predictive factors leading to a known CTD. We conducted the present study to evaluate the causes of RP in our area and followed the studied subjects to find prognostic factors indicating a definite CTD or remaining a UCTD. In this retrospective cohort study we included all adult patients with RP who were referred for capillaroscopy from 2010 to 2019. All the patients with primary and secondary RP with follow-up were evaluated for demography, laboratory results and capillaroscopy to find the risk factors of their progression to a CTD. A total of 760 of 776 patients were included, with 679 being female (89.3%) and 81 (10.7%) male. There were 660 subjects (90.8%) with secondary RP [mostly UCTD (48.2%) and then SSc (16.4%)] and 67 (9.2%) with primary RP; 109 patients were followed up and 42 (42%) of those with secondary RP developed a definite CTD. The scleroderma pattern and some capillary changes on capillaroscopy and/or positive ANA had statistically significant differences for CTD transition. We had a small number of patients with primary RP. The most prevalent causes of secondary RP in our patients were UCTD and SSc. Some capillaroscopy and laboratory results alone or in combination could be used as a predictive marker for the transition of patients with UCTD to CTD.