Abstract
A case of systemic lupus erythemaosus with an unusual complication of pulmonary hypertension leading to cor pulmonale is reported. Lung biopsy showed an interstitial pneumonitis with pulmonary vascular narrowing causing pulmonary hypertension. These changes appeared to be immunologically mediated by the utilization of IgG and C3. Microtubular virus-like particles were present in the endothelial cell cytoplasm of both lung and kidney.