Earlier reports showed that the leading cause of death in MCTD is pulmonary arterial .. Accepted for publication February 11. Mixed connective tissue disease (MCTD) is a rare autoimmune disorder that . MCTD, visit the Mayo Foundation for Medical Education and Research Web site. Mixed connective tissue disease (MCTD) is a rare connective tissue disorder combining clinical features of systemic lupus Français (, pdf) Classification(s) (5) · Gene(s) (0) · Publications in PubMed · Other website (s) (8) The documents contained in this web site are presented for information purposes only.