Changes in causes of death in systemic sclerosis, 1972-2002.
Posted Nov 12 2010 4:46am
Survival of scleroderma has changed since the renal crisis treatment has become possible. Aims: To document the changes in survival and organ system causes of mortality in systemic sclerosis (SSc) over the past 25 years in patients from a single medical centre.
Consecutive patients evaluated at the University of Pittsburgh, Pittsburgh, Pennsylvania, USA between 1 January 1972 and 31 December 1996 were studied. Survival was determined in five 5-year time periods between 1972 and 1997.
Causes of death included scleroderma-related (scleroderma renal crisis, pulmonary arterial hypertension, pulmonary fibrosis (PF) , gastrointestinal (GI), heart and multiorgan failure) and non-scleroderma-related (cancer, atherosclerotic cardiovascular or cerebrovascular disease, infection, sudden death, other and unknown) causes.
The 10-year survival improved steadily from 54% to 66% during each of the time intervals. There was a significant improvement in survival for patients during 1982-91 compared with those during 1972-81 (p<0.001), even when patients with renal crisis were excluded (p<0.005). The frequency of deaths due to renal crisis significantly decreased over the 30-year time period, from 42% to 6% of scleroderma-related deaths (p<0.001), whereas the proportion of patients with scleroderma who died of PF increased from 6% to 33% (p<0.001). The frequency of pulmonary hypertension, independent of PF, also significantly increased during this time period (p<0.05). There were no changes in scleroderma GI- and heart-related deaths, nor in any of the non-scleroderma-related causes, although patients with scleroderma were less likely to die from scleroderma-related problems in the past 15 years. CONCLUSION:
The change in the pattern of scleroderma-related deaths over the past 30 years demonstrates that the lung (both pulmonary hypertension and PF ) is the primary cause of scleroderma-related deaths today. It is important that aggressive searches continue to develop better therapies for these severe pulmonary complications of SSc.
A recent study shows that a loss of antioxidants in the endothelial cells that line blood vessels in the lungs contributes to the loss of vasodilator effects and, ultimately, to the development of pulmonary hypertension. The findings appear in Clinical and Translational Science.
The study, led by Serpil Erzurum of the Cleveland Clinic, evaluated antioxidant activities in patients with idiopathic pulmonary arterial hypertension (IPAH), a fatal disease characterized by progressive increase in pulmonary artery pressure and vascular resistance.
Erzurum's study found that the inactivation of these oxidants inside the cell is achieved mainly by the cell's own line of defense against oxidants. Additionally, the researchers determined that this process may contribute to low levels of nitric oxide, identified in IPAH and a fundamental component in the pathogenesis of pulmonary hypertension.
According to Dr. Erzurum, there is a potential long-term benefit to the care of patients with IPAH due to the study's findings. "Antioxidant augmentation in patients might be used to increase nitric oxide vasodilator effects, reduce pulmonary artery pressures and potentially improve clinical outcomes," she said.