Immunosuppressive therapy in patients with connective tissue disease‐associated pulmonary arterial hypertension: A systematic review

It is currently accepted that inflammation plays an important role in the pathogenesis of connective tissue disease-associated pulmonary arterial hypertension (CTD-PAH). However, the efficacy of immunosuppressive therapy remains anecdotal. The objective of this systematic review was to evaluate the efficacy of immunosuppressive therapy in patients with CTD-PAH and to further assess whether response differs between CTD subtypes and clinical features.We systematically searched studies reporting the treatment response of immunosuppressants and biological agents in CTD-PAH from PUBMED, EMBASE, the Cochrane Library, and Scopus. Studies had to report treatment regime and response criteria. The risk of bias was assessed using the Newcastle-Ottawa scale.Seven independent cohorts, 1 trial, and 1 case-series encompassing 439 patients with CTD-PAH were included. Patients were divided into 2 groups according to the therapeutic regimen. There were 146 patients in the immunosuppressants group with better heart function at baseline and 52.1% (76/146) of them were responders. There were 236 patients treated with immunosuppressants combined with PAH-specific therapy who showed more severity at baseline and 41.1% (97/236) of them were responders. Among different CTD subtypes, patients with systemic lupus erythematosus-associated PAH (SLE-PAH) showed a better response to immunosuppressants (response rate 48.1%). What is more, 1 randomized controlled trial showed the potential therapeutic value of rituximab (n = 57) in CTD-PAH patients.Current studies support the use of immunosuppressive therapy in CTD-PAH, especially in SLE-PAH. Further studies on biological agents and the therapeutic effect of different immunosuppressants are still needed.