Background/Purpose: In systemic sclerosis (SSc), capillary abnormalities progress in a clearly defined sequence called the “scleroderma patterns” (Early, Active, Late) (1-3). On the contrary, characteristic nailfold capillary abnormalities are not present in mixed connective tissue disease (MCTD) (1,2). Until today, few studies described the main nailfold videocapillaroscopy (NVC) changes in MCTD (4,5). The aim of this retrospective study was to compare nailfold capillary abnormalities in MCTD and SSc patients at first NVC visit, and to monitor MCTD capillary changes over a three year follow-up.

Methods: Ten patients (mean age 50±19 years, mean disease duration 6.4±4.2 years) affected by MCTD (Kasukawa’s criteria) who performed their first NVC were enrolled. Main capillary parameters (scores of capillary ramifications, enlarged capillaries, giant capillaries, microhemorrhages, number of capillaries, as well as absolute number of normal and total capillaries per linear millimetre) were evaluated in MCTD patients by NVC at baseline (T0, first NVC), and during a three year follow-up. Furthermore, NVC parameters were compared at T0 with 10 random SSc patients with the same disease duration (6.4±4.2 years) and similar age (51±17 years). Statistical analysis was performed by non parametric tests. The patients were receiving different immunosuppressive treatments.

Results: The scores of enlarged capillaries, giant capillaries and microhemorrhages were found significantly higher in patients with SSc versus MCTD patients at T0 (2.50±0.5 vs 1.90±0.6 p=0.04, and 1.63±0.7 vs 0.70±0.7 p<0.02, 1.25±0.7 vs 0.70±0.7 p=0.05, respectively). Moreover, the absolute number of total capillaries and normal capillaries were found significantly lower in SSc patients versus MCTD patients (5.8±1.9 vs 7.6±1.6 p=0.04 and 0.45±1.0 vs 3.03±2.9 p= 0.009). On the contrary, no statistically significant difference was observed for the other capillary parameters (including capillary ramifications) between the two groups of patients. No statistically significant variation of the scores as well as of the absolute value of the above reported capillary parameters was observed during the 3 years of follow-up in MCTD patients. No statistically significant correlation was observed between capillary parameters and MCTD clinical aspects (Raynaud phenomenon, dysphagia, dyspnoea, sclerodactily, sicca syndrome, teleangectasias and artharlgia) at first visit and during follow-up.

Conclusion: In a limited cohort of MCTD patients with an average disease duration of 6.4 years and a follow-up of three years, the nailfold microangiopathy does not seem to be significantly progressive. Patients with MCTD seem to show less enlarged/giant capillaries, and larger absolute number of total and normal capillaries than SSc patients.

References. 1.Cutolo M. et al. Best Pract Res Clin Rheumatol 2008; 22:1093-108. 2.Cutolo M. et al. J Rheumatol. 2000; 27:155-60. 3.Sulli A et al. Arthritis Rheum. 2012;64:821-5. 4.De Holanda Mafaldo DA, et al. Lupus. 2007; 16:254–8. 5.Cappelli S. et al. Semin Arthritis Rheum. 2012; 41:589-98.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/comparison-of-nailfold-microvascular-damage-in-mixed-connective-tissue-disease-versus-systemic-sclerosis-patients-during-a-three-year-follow-up/