Mixed connective tissue disease.

A study was done that involved 46 patients with high-titer serum antibody to ribonucleoprotein (RNP). Common cutaneous manifestations included swollen hands or sclerodactyly (50 percent), cutaneous lupus erythematosus (48 percent), periungual telangiectasia (46 percent), alopecia (46 percent), dyspigmentation (28 percent), photosensitivity (28 percent) and vasculitis (22 percent). Frequent systemic characteristics included Raynaud phenomenon (93 percent), arthritis or arthralgia (91 percent), adenopathy (43 percent), vascular headaches (35 percent), serositis (35 percent), hoarseness (28 percent), myositis (26 percent), sicca syndrome (24 percent), renal disease (17 percent) and central nervous system disease (9 percent). Associated laboratory findings included antinuclear antibodies (100 percent), epidermal nuclear lgG deposition (91 percent), hypergammaglobulinemia (78 percent), esophageal dysmotility (61 percent), abnormal pulmonary function (59 percent), rheumatoid factor (57 percent), lupus erythematosus cells (37 percent), positive lupus band test (34 percent), hypocomplementemia (28 percent) and elevated anti-nDNA (21 percent). It appears that patients with high-titer anti-RNP (without appreciable amounts of "anti-Sm") have a high prevalence of Raynaud phenomenon and a low prevalence of progressive renal insufficiency and severe central nervous system disease.