Background: The aim of this study was to assess the clinical presentation, complications and serological analysis of mixed connective tissue disease (MCTD) at King Faisal Specialist Hospital & Research Centre (KFSH&RC), and to determine the long-term clinical and immunologic outcomes.
Patients and methods: This was a retrospective study with prospective follow-up of 18 patients with MCTD who were followed at KFSH&RC between 1982 and 1999.
Results: The age at onset of the disease ranged from 6 to 44 years, with a mean age of 17.9 years. The female to male ratio was 2.5:1, and the mean follow-up time was 5 years. The most frequent presenting symptoms were arthralgia in all patients, Raynaud's phenomenon in 16 patients (88%) and swollen hands in 11 patients (61%). Arthritis was seen in 12 patients (67%) and definite myositis in 10 patients (58%). The most common skin rashes encountered included lupus-like rash in 8 patients (44%), scleroderma-like rash in 8 patients (44%), and cutaneous vasculitis in 5 patients (28%). Pulmonary hypertension occurred in 4 patients (22%). Other clinical manifestations encountered were esophageal hypomotility in 10 patients (56%), myocarditis in 2 patients (11%) and proteinuria in 2 patients (11%), while various neurological manifestations were present in 7 patients (39%). All patients exhibited high titer of ANA and anti-nRNP antibodies. Five of the 18 patients (28%) had marked reduction in the anti-nRNP during remission. Following treatment, features of inflammation as well as Raynaud's phenomenon and esophageal hypomotility diminished, while pulmonary hypertension persisted. A favorable outcome was observed in 12 patients (67%); 3 patients (17%) had continued active disease, while 3 patients (17%) died, with death related to pulmonary hypertension occurring in two patients (11%).
Conclusion: The studied patients demonstrated the typical clinical and serological findings of MCTD, which support the correlation between anti-nRNP antibody specificities and MCTD. Autoantibody reactivity against nRNP polypeptides tends to regress during prolonged disease remission. The majority of our patients had favorable outcomes, with pulmonary hypertension being the most frequent disease-associated cause of morbidity and mortality.