The Role Of Microcirculation Examination In The Diagnosis And Evaluation Of Systemic Sclerosis

BackgroundSystemic sclerosis is an autoimmune disease with uncertain etiology. It characterized with fibrosis, vasculopathy, and autoantibodies targeting multiple antigens of the cell. The typical clinic manifestation is skin swelling, followed by thickening and sclerosis. Besides that, the disease also involves vascular, lung, gastrointestinal tract, kidney, heart, etc. Nailfold vediocapillaroscopy is an noninvasive test to the microvascular, and has been widely applied internationally to evaluate the microvasculopathy, monitor the change of severity of the disease and also evaluate the effect of the therapy. In2013, American College of Rheumatology/European League Against Rheumatism took abnormal nailfold capillaries as an item in the new classification criteria for systemic sclerosis. But currently in our country, nailfold videocapillaroscopy is not well accepted or applied in rheumatology. The research focused on the contribution of nailfold videocapillaroscopy to the diagnosis of systemic sclerosis and evaluation of the severity of the disease. The research included the validation of the2013classification criteria and exploring the potential correlation of the nailfold videocapillaryscopy results, the clinical manifestation, and the serum cytokine (endothelin-1, interleukin-6) level.MethodsRecruit patients diagnosed with systemic sclerosis, patients diagnosed with other connective diseases while once having systemic sclerosis to rule out as disease control, and healthy adults as healthy control. Gather the clinical data of all the patients, perform the nailfold videocapillaroscopy test on all the subjects, and detect the serum cytokine (endothelin-1, interleukin-6) level of them. Assess all the patients with both the classification criteria. Calculate and compare the sensitivity and specificity of the two classification criteria. Analyze the correlation of the nailfold videocapillaroscopy results, clinical manifestation and serum cytokine (endothelin-1, interleukin-6) level.ResultsIn this research, the sensitivity of the2013classification criteria for systemic sclerosis of American College of Rheumatology/European League Against Rheumatism (95%,95%CI90%-99%) is better than the1980classification criteria(70%,95%CI60%-79%)(P=0.000). But there is no significant difference between the specificity of the two classification criteria (95%,95%CI89%～100%and97%,95%CI92%～100%respectively, P=1.000).In systemic sclerosis, the nailfold videocapillaroscopy results are correlated with the Rodnan modified score and the vasculopathy. The density decrease of the nailfold capillaries, irregularly enlarged capillaries and capillary disorganization are relevant index. As for Raynaud’s phenomenon, patients used to with it have more sever density decrease compared with patients who never suffer it in their whole history. Patients with Raynaud’s phenomenon currently not only have more sever density decrease, but also have more rregularly enlarged capillaries and worse capillary disorganization, compared with patients without Raynaud’s phenomenon now. Patients with digital ulcer are worse in all these three index. Patients with telangiectasia and patients with pulmonary artery hypertension have more sever density decrease.In our systemic sclerosis patients, some nailfold videocapillaroscopy indexes are in correlation with serum endothelin-1or interleukin-6level. Low density decrease of the nailfold capillaries is correlated with higher serum endothelin-1level (P=0.020). Worse capillary disorganization is correlated with higher serum endothelin-1level (P=0.014), and correlated with higher serum interleukin-6level (P=0.003).In this research, the serum endothelin-1or interleukin-6level is not significantly correlated the vasculopathy. However, patients suffering with higher Rodnan modified scores tend to have higher serum interleukin-6level.ConclusionsNailfold videocapillaroscopy is a useful tool in diagnosis of systemic sclerosis and evaluation of the severity of the disease. With nailfold videocapillaroscopy, the sensitivity of the2013classification criteria for systemic sclerosis of American College of Rheumatology/European League Against Rheumatism is better than the1980classification criteria. But there is no significant difference between the specificity of the two classification criteria. In systemic sclerosis, the nailfold videocapillaroscopy results are correlated with the Rodnan modified score and the manifestation of vasculopathy. including Raynaud’s phenomenon, digital ulcer, telangiectasia and pulmonary artery hypertension. The density decrease of the nailfold capillaries, irregularly enlarged capillaries and capillary disorganization are relevant indexes. Some nailfold videocapillaroscopy indexes are in correlation with serum endothelin-1or interleukin-6level. But the serum endothelin-1or interleukin-6level is not significantly correlated the vasculopathy. However, patients suffering with higher Rodnan modified scores tend to have higher serum interleukin-6level.