Nailfold Capillaroscopic Features in Children with Juvenile Systemic Sclerosis

Abstract

Aim. To identify the nailfold capillaroscopic features in children with confirmed juvenile systemic sclerosis (JSSc) and the parameters associated with decreased capillary density. Design. Two-center retrospective cohort study. Materials and methods. The study included 43 patients with confirmed JSSc (35 girls, 8 boys; median age of 14 (10; 15) years). The diagnosis was established according to the Paediatric Rheumatology European Society/American College of Rheumatology/European Alliance of Associations for Rheumatology (2007) criteria. Nailfold capillaroscopy (NFC) was performed according to the European Alliance of Associations for Rheumatology standard. The capillary density, maximum apical diameter, morphology, the presence of giant capillaries, microhemorrhages, avascular areas, perivascular edema, and extravasates were assessed. Since there is no convincing evidence that scleroderma patterns can be defined in children, individual quantitative and qualitative NFC parameters were assessed rather than using a pattern-based classification system. Results. Decreased capillary density (< 7 capillaries per 1 mm) was detected in 35 (81.4%) of 43 patients; the median density was 5 (4; 6) capillaries per 1 mm. Capillary dilation was noted in 41 (95.4%) of 43 children, giant capillaries in 20 (46.5%), abnormal morphology in 40 (93%), perivascular edema in 24 (55.8%), and microhemorrhages in 15 (34.9%). The median maximum apical capillary diameter was 45 (36, 68) μm. When comparing children with normal (n = 8) and decreased (n = 35) capillary density, patients with decreased density were older (with a median age of 14 vs. 10 years; p = 0.008), and they had a significantly higher prevalence of Raynaud's phenomenon (68.6% vs. 25%; p = 0.042; odds ratio (OR) = 6.5; 95% confidence interval (CI): 1.1 to 37.8) and arborized capillaries (74.3% vs. 25%; p = 0.014; OR = 8.7; 95% CI: 1.5 to 50.9). Giant capillaries and perivascular edema occurred exclusively in this group: 57.1% (p = 0.004; OR = 22.5; 95% CI: 1.2 to 420.0) and 68.6% (p < 0.001; OR = 39.7; 95% CI: 2.1 to 752.0), respectively. In contrast, hairpin capillaries were more often observed with normal density (87.5% vs. 40%; p = 0.021; OR = 0.095; 95% CI: 0.01 to 0.86). There was no statistically significant association between decreased capillary density and the presence of interstitial lung disease (54.3% vs. 37.5%; p = 0.457). The analysis was descriptive; no correction for multiple comparisons was applied. Conclusion. In children with JSSc, decreased capillary density, dilated and giant capillaries, abnormal morphology, and perivascular edema were common. Decreased capillary density was associated with age, Raynaud's phenomenon, and qualitative parameters such as giant capillaries, arborized capillaries, and perivascular edema. The findings justify the need to develop age-specific reference values for NFC and further prospective studies to clarify the prognostic value of individual capillaroscopic parameters in JSSc. Keywords: juvenile systemic sclerosis, nailfold capillaroscopy, microcirculation, capillary density, children.