NVC Imaging Technique May Offer Way of Foreseeing Risk to Organs
Nailfold videocapillaroscopy (NVC), a technique to detect small changes in circulation, may be a promising biomarker of likely severe organ involvement in people with systemic sclerosis (SSc) although more data is needed, according to a recent study.
“The generation of consistent high-quality research in this area may lead to the future integration of NVC as a predictive biomarker into daily SSc practice, to timely initiate and/or escalate treatment in specific high-risk subgroups,” the researchers wrote.
The study, “Nailfold capillaroscopy in SSc: innocent bystander or promising biomarker for novel severe organ involvement/progression,” was published in the journal Rheumatology.
While some people with SSc (also known as scleroderma) develop only mild symptoms, others can experience severe disease progression, with dysfunction in organs that include the heart, lungs, and vascular system as well as the skin. In such cases, early identification is key for close monitoring and targeted treatment.
Nailfold videocapillaroscopy is a noninvasive imaging technique that detects small and detailed changes in the skin’s circulation, or its microvasculature. Previous data showed that NVC could detect early microvascular damage caused by SSc, and it was proposed as a diagnostic tool for identifying the disease.
More recently, it has been suggested that NVC may be a biomarker for disease progression in SSc.
To determine whether NVC has predictive value for the development of severe organ involvement in SSc, researchers across Europe evaluated data from 334 adult SSc patients at seven European centers between 2008 and 2016.
At the study’s start, or baseline, 242 patients (72.5%) had an NVC pattern consistent with scleroderma. Among those, 189 were considered to have “severe” NVC patterns.
During two years of follow-up, 257 patients (76.9%) developed severe organ involvement, including 199 women. Ninety cases were classified as diffuse SSc and 159 were classified as limited forms of SSc.
Severe NVC patterns occurred significantly more often in patients who later developed severe organ involvement (61.4%) than in those who did not (42.9%).
Accordingly, severe NVC patterns correlated with the future development of severe organ involvement or progression during follow-up. Specifically, patients with severe NVC patterns were more likely to develop peripheral vascular involvement — affecting the blood vessels and circulatory system — and progressive skin symptoms.
The skin finding is “particularly important, as skin fibrosis [scarring] is not only a prominent debilitating clinical manifestation of SSc but is also of prognostic importance as the rate and degree of progression appear to correlate with organ involvement and mortality,” the researchers wrote.
Normal capillary density, or the number of small blood vessels, was associated with fewer cases of severe organ involvement.
Microhemorrhages, or small blood vessel bleeds, were associated with fewer occurrences of pulmonary hypertension — a lung disorder marked by increased pressure in the arteries supplying blood to the lungs. This result was in contrast to previous findings that microhemorrhages indicate greater disease activity, according to the team.
While prior data suggested that NVC may be a promising biomarker of lung involvement in SSc, including pulmonary arterial hypertension and interstitial lung disease (a group of disorders that generally involve progressive scarring of lung tissue), that finding was not reported in this study.
Researchers suggested this could be explained by a low occurrence of these complications in the study group, perhaps partly due to a relatively short follow-up time.
To confirm their overall observations, more data will be needed, including a larger number of patients from all disease stages and NVC measures taken more than once in each patient, the researchers noted.
“This study provides additional evidence for a future shift towards the use of NVC as an optional indicator of more severe disease in SSc, with important clinical implications in its overall management,” the team wrote.
They noted, however, that “it should not be overlooked that NVC is currently not widely used outside academic centres in Europe, nor in most centres in the United States, thus limiting its potential feasibility as a biomarker (at this time).”