Systemic Sclerosis and Systemic Lupus Erythematosus Overlap Syndrome with Pulmonary Arterial Hypertension Successfully Treated with Immunosuppressive Therapy and Riociguat

We report the case of a 40-year-old patient with systemic sclerosis (SSc) and systemic lupus erythematosus (SLE) overlap syndrome with pulmonary arterial hypertension (overlap-PAH) that was successfully treated with a combination of immunosuppressive therapy and the soluble guanylate cyclase stimulator riociguat. She was diagnosed with mixed connective tissue disease (MCTD) two years prior to admission. She was admitted to our hospital with dyspnea on exertion and progressive skin sclerosis. She fulfilled both SLE and SSc classification criteria and was re-diagnosed with overlap syndrome. The tricuspid valve pressure gradient (TRPG) on echocardiography was 64 mmHg at admission. On right heart catheterization, mean pulmonary arterial pressure (mPAP) was 43 mmHg and pulmonary capillary wedge pressure was 15 mmHg. We diagnosed her with SSc-SLE overlap-PAH and started treatment with corticosteroids and intravenous cyclophosphamide. We also started treatment with riociguat because we speculated she had a component of SSc-PAH and that immunosuppressive therapy alone may be insufficient. We chose riociguat because of its favorable treatment effect on SSc-PAH. Two months after treatment, her TRPG improved to 33 mmHg and the skin sclerosis improved dramatically, suggesting the efficacy of multi-drug treatment and the importance of early intervention.