Both nailfold videocapillaroscopy (NVC) and digital thermal monitoring (DTM) can be used complementarily as investigative tools in the quantification of vasculopathy in systemic sclerosis (SSc)-Raynaud phenomenon (RP), according to study results published in The Journal of Rheumatology. Researchers observed that increased advanced vasculopathy and structural abnormalities correlated to reduced microvascular function as detected by DTM and NVC, respectively.
Raynaud phenomenon is typically the earliest symptom of SSc and presents in nearly all patients with SSc. While NVC is the gold standard for quantification of vascular abnormalities in SSc-RP, DTM helps in the evaluation of microvascular functional dysfunction related to thermoregulation. In the present study, investigators explored the correlation of NVC patterns and DTM variables in patients with SSc.
Participants enrolled in a single center SSc registry who underwent NVC and DTM were included in the study. Researchers recorded the clinical features of SSc and obtained DTM of both hands. Doppler ultrasound hyperemic, low frequency, blood velocity of radial artery, and fingertip vascular function were assessed for DTM, and a vascular reactivity index (VRI) measurement was automated. Researchers performed NVC to classify patients into 1 of the 3 qualitative patterns of SSc microangiopathy: early, active, or late. Parameters, including number of capillaries/mm, number of enlarged and giant capillaries, microhemorrhages, and avascular score, were analyzed in 8 fingers of the hands (excluding the thumbs). Nonparametric tests were used to evaluate the correlation of the NVC and DTM variables.
The study included 31 patients with SSc with interpretable NVC and DTM performed on the same day. A total of 30 patients (91%) were women, with a mean age of 58±12 years. Mean durations from RP and first non-RP symptom of SSc were 13.1±5 years and 10.8±8 years, respectively. Results showed that VRI was progressively higher in patients with SSc with the early, active, and late NVC patterns of microangiopathy (Kruskal-Wallis test; P <.0001), which indicated that more advanced vasculopathy and structural abnormalities may be associated with reduced microvascular function. Furthermore, a significant negative correlation was noted between VRI and microhemorrhages score (Spearman’s rank correlation; r=-0.363; P =.044), which suggested no correlation with thermoregulation. In addition, no significant correlation was observed between VRI and number of capillaries/mm, number of enlarged and giant capillaries, or avascular score.
Study limitations included the use of a single center study with a small sample size and the enrollment of an ethnically similar population with cutaneous SSc.
Investigators concluded, “NVC and DTM may provide different aspects of vasculopathy quantification and complement each other as investigative tools.”
Thomas J, Radic M, Tucker JR, Overbury R, Frech T. Raynaud’s phenomenon in systemic sclerosis: Does digital thermal monitoring correlate to specific nailfold videocapillaroscopy abnormalities? [published online June 2020]. J Rheumatol. doi:10.3899/jrheum.191371