Nailfold Capillaroscopy in Early Stages of Mixed Connective Tissue Disease in a Sample of Egyptian Patients

Abstract

Introduction: Mixed connective tissue disease (MCTD) is a systemic autoimmune disease with a high titer of anti-U1 small nuclear ribonucleoprotein particles and a number of clinical pictures, mainly Raynaud's phenomenon. Nailfold capillaroscopy (NFC) is a noninvasive diagnostic tool for patients with different connective tissue diseases that permit detection of local microvascular changes that correlate with systemic vascular involvement. Aim of the Study: The aim of this study was to compare the results of NFC in patients with systemic sclerosis (SSc) and MCTD to determine the chief characteristics of skin microangiopathy in early MCTD and attempt to describe a characteristic MCTD pattern in Egyptian patients. Methodology: This cross-sectional study included forty patients diagnosed with MCTD according to Alarcón-Segovia and Villareal criteria and twenty patients with confirmed systemic sclerosis according to the American College of Rheumatology and the European League against Rheumatism classification criteria for Systemic Sclerosis. Nailfold examination for the study subjects was performed describing architectural derangement, capillary density changes, mega capillary and enlarged loops, microhemorrhages, and angiogenesis. Results: Of the sixty patients studied, 49 (81.7%) patients were females and 11 were males with a mean age of 31 years with a median of 29.5 and range 16–52 years. Three of the twenty patients diagnosed with systemic sclerosis had arthritis. Out of sixty patients, 53.3% had thickened skin, 19 patients exhibited puffy fingers, six patients showed rash, and none had swollen joints. The skin was significantly thicker in systemic sclerosis patients (85%) compared to 37.5% in the MCTD population. Patients presented with various features, the most common of which was fatigue (26.7%) and myositis (23% of patients). There is a significant negative correlation of −0.508 (P = 0.022) between the enlargement scores and illness duration in systemic sclerosis patients. Those patients also exhibited a statistically significant positive correlation of 0.520 (P = 0.019) between hemorrhage score and the number of tender joints. Alternatively, patients diagnosed with MCTD exhibited a significant positive correlation between the architectural changes scores of their joints and both the duration of their illness (0.347; P = 0.028) and the number of swollen joints (0.424; P = 0.006). MCTD patients also showed a significant correlation of 0.423 (P = 0.007) between their hemorrhage scores and their age at the time of the study. Conclusion: In this study, the results obtained were qualitatively satisfactory for clear delineation of the nailfold capillaries features in MCTD. Therefore, it aids in the recognition of alternations in nailfold capillaries making an early prediction of course of illness in MCTD patients possible and suggests a potential ability to differentiate from early SSc, thus helps in preventing morbidities and sequelae of the disease.