Immunosuppressive therapy in connective tissue diseases-associated pulmonary arterial hypertension.

Study Objective: Immune and inflammatory mechanisms could play a significant role in pulmonary arterial hypertension (PAH) genesis or progression, especially in patients with connective tissue diseases. Immunosuppressive therapy should be better evaluated in this setting.
Study Design: Monocentric retrospective study.
Patients: We reviewed the clinical and hemodynamic effects of immunosuppressants administered as first-line monotherapy to 28 consecutive patients with connective tissue disease-associated PAH.
Interventions: All patients received a monthly IV bolus of cyclophosphamide, 600 mg/m2, for at least 3 months, and 22 of 28 patients received systemic glucocorticosteroids. Responders to immunosuppressive therapy were defined as patients who remained in New York Heart Association (NYHA) functional class I or II with sustained hemodynamic improvement after at least 1 year of immunosuppressive therapy without addition of prostanoids, phosphodiesterase type 5 inhibitors, or endothelin receptor antagonists.
Results: Eight of 28 patients (systemic lupus erythematosus [SLE], n = 5; mixed connective tissue disease [MCTD], n = 3) [29%] were responders. These patients had a significantly improved 6-min walking distance (available in five patients) and a significant improvement in hemodynamic function. No patients with systemic sclerosis responded, while 5 of 12 patients with SLE and 3 of 8 patients with MCTD did respond. Survival analysis indicated that responders had a better survival than nonresponders. Patients with a lower baseline NYHA functional class and better baseline pulmonary hemodynamics (p < 0.05) were more likely to benefit from immunosuppressive therapy.
Conclusion: PAH associated with SLE or MCTD might respond to a treatment combining glucocorticosteroids and cyclophosphamide.