Background Systemic sclerosis (SSc) is an autoimmune disease characterized by immunological features, microvascular disturbances and fibrosis as a consequence of a massive production of extracellular matrix.
Objectives The aim of this study was to analyse the alterations of the capillary nailfold bed and describe their correlation with clinical variables.
Methods 134 patients were selected with SSc according to LeRoy and Medsger diagnostic criteria from the Hospital Universitari Vall d'Hebron cohort. Patients underwent an echocardiogram, pulmonary function test and nailfold videocapillaroscopy (NVC) within a 3 months period. NVC was performed from 2nd to 5th finger of both hands. NVC features were quantitatively measured. Informed consent was obtained by all the participants. SPSS 20.0 were used for statistical analysis. A P-value <0.05 was considered as significant.
Results Female was the predominant gender (113, 84.3%). The most common cutaneous subtypes were limited SSc, diffused SSc (88, 65.7% and 28, 20.9%, respectively). Almost 80% of patients met the ACR/EULAR 2013 classification criteria. The age (± standard deviation) at NVC was 38.5 (± 15.7) years, and the interval from the first SSc symptom and NVC was 16 (± 12.6) years. Anti-centromere antibodies (ACA) were the most frequent in 36.6% of patients, followed by anti-topoisomerase I in 23.1%. Regarding organ involvement, 62 (46.3%) patients suffered from digital ulcers, 58 (43.3%) interstitial lung disease (ILD), 11 (8.2%) pulmonary hypertension, 110 (82.1%) gastrointestinal disturbances and 103 (76.9%) some cardiac alterations. The forced vital capacity was 80.8 (± 20.1) % and diffusion capacity for carbon monoxide (DLCO) was 66.2 (± 23.7) %. Regarding echocardiography results, the tricuspid regurgitation velocity (TRV) was 2.8 (± 0.3) m/s and the right ventricular systolic pressure 30.7 (± 12.0) mmHg. NVC findings were described as follows: the median of number of capillaries was 5.4 /mm, enlarged capillaries 0.8/mm, giant capillaries 0.2 /mm, microhemorragies 0.1 /mm, ramified capillaries 0.3 /mm, tortuous capillaries 0.6 /mm and disorganized capillaries 0.0 /mm. SSc-ILD patients presented lower capillary density 4.8 /mm compared with 5.8 /mm in the other group (P=0.005), and also more frequent ramified capillaries 0.3 /mm compared with 0.2 /mm (P=0.013). With respect to the correlations, the number of capillaries was related with the DLCO (rho =0.26, P=0.003) but negatively with the RVSP (rho = - 0.21, P=0.03). Giant capillaries were correlated with LVEF (rho =0.27, P=0.001) and greater tricuspid annular plane systolic excursion (TAPSE) (rho =0.21, P=0.01). Microhemorraghies were associated with LVEF (rho =0.29, P=0.001) although negatively with age at NVC (rho = - 0.25, P=0.003) and time from first symptom (rho = - 0.25, P=0.003). Disorganized capillaries were related with age at NVC (rho =0.17, P=0.04) but negatively with DLCO (rho = - 0.18, P=0.035).
Conclusions The existence of a correlation between NVC features and clinical variables suggests that microvascular alterations may play a role as a pathogenic link with the cardiopulmonary SSc manifestations.
Acknowledgements Guillen-Del Castillo A. is a researcher supported by the Contratos Predoctorales de Formaciόn en Investigaciόn (PFIS) grant from Instituto de Salud Carlos III [FI14/00643].
Disclosure of Interest None declared