Background Naifold videocapillaroscopy (NVC) is an useful diagnostic test for the early diagnosis and monitoring of Systemic sclerosis (SSc). The NVC semiquantitative evaluation (scleroderma pattern early, active and late) is widely used for its prognostic value of the organ involvement, particularly of the lung. Some authors have proposed quantitative measurements of the following capillaroscopic parameters (also called QNVC parameters): number of giant capillaries (M), number of capillaries in the distal row (N), maximum diameter of giant capillaries (D) and M:N ratio. Recently two scores were developed to assess the nailfold microvascular damage and the digital ulcers risk [1-2]. Interstitial lung disease related to SSc (ILD-SSc) can be assessed by pulmunary function test (PFTs) and by semiquantitative scores based on the extent of radiological lesions presented on pulmonary CT. Goh et al.  have proposed a semiquantitative grading system of ILD-SSc that provides discriminatory prognostic information.
Objectives To verify the correlation between QNVC parameters and ILD-SSc extent evaluated by pulmunary function tests and by Goh et al. semiquantitative grading system. Furthermore to compare the distribution of ILD-SSc extent and QNVC parameters in the groups of patients with different capillaroscopic pattern.
Methods 24 patients with SSc (all met the ACR/EULAR classification criteria for SSC) were examined in a period of three months with the following test: NVC, chest CT e PFTs. NVC was performed according to Sulli et al. . Two experienced rheumatologist in NVC (7 and 6 years) evaluate the images of each patient providing the following QNVC parameters: M, N, D, M:N. Chest CTs were evaluated by two radiologists with 15 and 6 years experience in ILD-SSc evaluation. Spearman rank test was used to verify the correlations between QNVC parameters, PFTs data and CT radiological assessment. Kruskal-Wallis test was used to assess QNVC parameters and CT radiological assessment differences between patients clustered according to capillaroscopic pattern. A p-value <0.05 was considered significant.
Results The following QNVC parameters correlate with CT radiological assessment: number of megacapillaries (r = -0,488; p=0,399), density of giant capillaries (p = -0,501; p=0,0343), maximum diameter of megacapillaries (r = -0,685; p=0,0017), M:N ratio (r = -0,502; p=0,0338). The only QNVC correlating with FVC is maximum diameter of megacapillaries (r =0,488; p=0,0212). All NVC parameters had a statistically different distribution between patients with early, late and active scleroderma pattern (p<0.05). Pulmonary fibrosis extent among the three groups, although different, has not reached statistical significance.
Conclusions In our study the ILD-SSc extent correlates with maximum diameter and number of giant capillaries. These findings suggest that the loss and dimensional change of giant capillaries could be indicative of a pulmonary evolution towards ILD. Hopefully with more numerous cohorts it might be developed a NVC score to predict ILD presence and/or extent.
Sulli A, et al. J Rheumatol. 2013 May;40(5):634-9.
Sebastiani M, et al. Arthritis Rheum. 2009 May 15;61(5):688-94
Goh NS et al, Am J Respir Crit Care Med. 2008 Jun 1;177(11):1248-54
Disclosure of Interest None declared
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