Objective: To determine the natural history and timing of severe involvement of the kidney, heart, lung, gastrointestinal (GI) tract, and skin in patients with systemic sclerosis (SSc) and diffuse cutaneous involvement.
Methods: This study used the Pittsburgh Scleroderma Databank and included patients with diffuse scleroderma who were seen between January 1, 1972 and December 31, 1995. Patients had frequent follow-ups, and a 95% accountability for these patients was maintained. Severe organ involvement was defined as the presence of any of the following: 1) in the kidney, scleroderma "renal crisis"; 2) in the heart, cardiomyopathy, symptomatic pericarditis, or an arrhythmia requiring treatment; 3) in the lung, pulmonary fibrosis on chest radiograph and a forced vital capacity of <55% of predicted; 4) in the GI tract, malabsorption, repeated episodes of pseudoobstruction, or severe problems requiring hyperalimentation; and 5) in the skin, a modified Rodnan skin score >40. The timing from disease onset to survival for each case of severe organ involvement was determined.
Results: Of the 953 patients with diffuse scleroderma, kidney involvement developed in 177 (19%), heart involvement in 143 (15%), lung involvement in 151 (16%), GI tract involvement in 74 (8%), and skin involvement in 233 (24%). Severe skin and kidney involvement occurred during the first 3 years in 70% of those who ever developed these problems throughout a mean of 10 years of followup. Severe heart, lung, and GI tract involvement developed during the first 3 years in 45-55% of those who were ever affected. The survival of patients with severe organ involvement was poor. The 9-year cumulative survival rate of all patients with severe organ involvement was 38%, compared with 72% in patients without such involvement (P < 0.0001).
Conclusion: This study demonstrates that severe organ involvement in SSc patients with diffuse scleroderma most often occurs early in the course of the disease. Survival for patients with severe organ involvement is markedly reduced. Patients should therefore be monitored very closely during the first 3 years of disease for signs and symptoms that may signal the subsequent development of severe organ damage. Potential disease-modifying therapies must be initiated early to modify the natural history of SSc and to improve survival. Patients who survive the first few years without developing severe organ involvement are less likely to develop such life-threatening involvement later in the disease course.