Diagnostic Significance Of Microcirculation Examination In Patients With Systemic Sclerosis And Its Correlation With Disease

Background & ObjectivesSystemic sclerosis is an autoimmune disease of uncertain etiology. Besides typical skin manifestations, multiple internal organ involvement is another prominent feature of the disease, leading to a poor prognosis. Systemic sclerosis is characterized by alterations of the microvasculature. As a noninvasive test, nailfold vediocapillaroscopy has been widely applied world-wide to evaluate the microvasculopathy. However, it is poorly applied in rheumatology clinics in China. In 2013, American College of Rheumatology/European League Against Rheumatism developed a new classification criteria for systemic sclerosis adding "abnormal nailfold capillaries" as one of the items. In 2014, a clinical research of our hospital demonstrated that the 2013 classification criteria had a higher sensitivity than the 1980 criteria with no significant difference in the aspect of specificity. On this basis, we want to expand the sample size as well as the disease spectrum of the disease control group to further explore the contribution of nailfold videocapillaroscopy to the diagnosis of systemic sclerosis in Chinese population. Some researches demonstrated that microvasculopathy mainly affects peripheral blood vessel, skin, lung and heart in systemic sclerosis, suggesting the potential correlation of nailfold videocapillaroscopy results with the clinical manifestations. We want to investigate the correlation in this research.Serum soluble CD 146 is suspected to be associated with vascular lesions by some researches. However, there have been no reports regarding the serum sCD146 level of patients with systemic sclerosis to date. This research aims to investigate the potential correlation between nailfold videocapillaroscopy results, the clinical manifestations and serum soluble CD 146 level.MethodsThis research is based on the European League Against Rheumatism Scleroderma Trials and Research (EUSTAR) database.Subjects:Patients diagnosed with systemic sclerosis, as well as patients diagnosed with other diseases similar to systemic sclerosis and healthy adults were included. Methods:Nailfold videocapillaroscopy tests were performed on all of the subjects. Clinical data were gathered and serum was collected from all of the patients. Both of the classification criteria were assessed to compare the sensitivity and specificity (including data from the research in 2014). Serum soluble CD 146 levels were measured for patients with systemic sclerosis and healthy controls from medical examination center. The correlation between the nailfold videocapillaroscopy results, clinical manifestations and serum soluble CD146 level was analyzed.ResultsIn this research (including data from the research in 2014), the sensitivity of the 2013 classification criteria for systemic sclerosis of American College of Rheumatology/European League Against Rheumatism is higher than the 1980 classification criteria(95.10% VS 72.03%, P<0.001). But still, there is no significant difference between the specificity of the two classification criteria (97.70% VS 94.25%, P=0.375). In systemic sclerosis, the nailfold videocapillaroscopy results are more correlated with vasculopathy. Patients with Raynaud’s phenomenon or digital ulcers in the course of disease have a decreased number of nailfold capillaries (P<0.001 & P=0.001 respectively). Patients with telangiectasia in the course of disease have not only a decreased number of nailfold capillaries (P=0.006) but also more disorganized capillaries (P=0.022). Nailfold videocapillaroscopy results, especially capillary number reduction, are also correlated with lung, heart and gut involvement. Patients with gastric involvement in the course of disease have not only a decreased number of nailfold capillaries (P=0.007) but also more disorganized capillaries(P=0.039). Patients with systemic sclerosis-associated pulmonary arterial hypertension(PAH) in the course of disease have a decreased number of nailfold capillaries than those without (P=0.037). The score for nailfold capillary number is associated with tricuspid valve regurgitation velocity(r=0.586,P=0.017) as well as pulmonary artery systolic pressure (r=0.542, P=0.030). Patients with abnormal diffusing capacity of the lung have a decreased number of nailfold capillaries (P=0.018). The score for nailfold capillary number is also associated with DLCO (r=-0.331, P=0.014). Nevertheless, no clear correlation between interstitial lung disease and nailfold videocapillaroscopy results is found. Serum soluble CD146 is elevated in systemic sclerosis (P<0.001), and is correlated with both the score for nailfold capillary number (r=0.316, P=0.026) and capillary ramifications (r=0.333, P=0.018), implying its potential correlation with vasculopathy.ConclusionsNailfold videocapillaroscopy is a useful tool in the diagnosis of systemic sclerosis. We demonstrated that the sensitivity of the 2013 classification criteria is higher than the 1980 classification criteria. But we could not find any significant difference between the specificity of the two classification criteria. The nailfold videocapillaroscopy results are correlated with vasculopathy, as well as lung, heart and gut involvement. Decreased nailfold capillary number can better reflect the severity of clinical manifestations. Serum soluble CD146 is elevated in systemic sclerosis, implying its potential correlation with vasculopathy.