Characterisation of mixed connective tissue disease - abstract

ABSTRACT

Of sixteen patients with MCTD, 10 62 percent) presented with the clinical features of systemic lupus erythematosus (SLE) and 6 (37 percent) with SLE-scleroderma. Ninety-four per cent had a speckled antinuclear factor pattern and 100 percent had IgG deposits in a speckled pattern within the epidermal cell nuclei of the skin. Seventy per cent of these patients had nRNP antibodies. These characteristics are more typical of the mixed connective tissue syndrome than of SLE or scleroderma. The low incidence of Raynaud's phenomenon in our group of patients (18 percent) with MCTD is probably due to the tropical climate. The IgM deposits in the skin of a significant number (67 percent) of the patients with the clinical picture of SLE-scleroderma probably represent an early stage in the development of the disease. The significance of high serum IgA in the clinically diagnosed SLE group is not understood and is now being further investigated. This study strongly suggests that laboratory investigations are of primary importance in distinguishing MCTD from SLE and other forms of collagen vascular diseases (AU)