Autoimmunity Is a Significant Feature of Idiopathic Pulmonary Arterial Hypertension.


Type
Article
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Authors
Groves, Emily 
Zalewska, Kasia I 
Swietlik, Emilia M 
Abstract

Rationale: Autoimmunity is believed to play a role in idiopathic pulmonary arterial hypertension (IPAH). It is not clear whether this is causative or a bystander of disease and if it carries any prognostic or treatment significance. Objectives: To study autoimmunity in IPAH using a large cross-sectional cohort. Methods: Assessment of the circulating immune cell phenotype was undertaken using flow cytometry, and the profile of serum immunoglobulins was generated using a standardized multiplex array of 19 clinically validated autoantibodies in 473 cases and 946 control subjects. Additional glutathione S-transferase fusion array and ELISA data were used to identify a serum autoantibody to BMPR2 (bone morphogenetic protein receptor type 2). Clustering analyses and clinical correlations were used to determine associations between immunogenicity and clinical outcomes. Measurements and Main Results: Flow cytometric immune profiling demonstrates that IPAH is associated with an altered humoral immune response in addition to raised IgG3. Multiplexed autoantibodies were significantly raised in IPAH, and clustering demonstrated three distinct clusters: "high autoantibody," "low autoantibody," and a small "intermediate" cluster exhibiting high concentrations of ribonucleic protein complex. The high-autoantibody cluster had worse hemodynamics but improved survival. A small subset of patients demonstrated immunoglobulin reactivity to BMPR2. Conclusions: This study establishes aberrant immune regulation and presence of autoantibodies as key features in the profile of a significant proportion of patients with IPAH and is associated with clinical outcomes.

Description
Keywords
BMPR2, IPAH, autoantibodies, autoimmune, pulmonary arterial hypertension, Autoantibodies, Autoimmunity, Cross-Sectional Studies, Familial Primary Pulmonary Hypertension, Humans, Hypertension, Pulmonary
Journal Title
Am J Respir Crit Care Med
Conference Name
Journal ISSN
1073-449X
1535-4970
Volume Title
Publisher
American Thoracic Society
Sponsorship
Medical Research Council (MC_UU_00002/4)
Wellcome Trust (220788/Z/20/Z)
Wellcome Trust (107881/Z/15/Z)
Medical Research Council (MR/K020919/1)
British Heart Foundation (None)
British Heart Foundation (None)
British Heart Foundation (PG/17/1/32532)
British Heart Foundation (PG/17/58/33134)
British Heart Foundation (SP/18/10/33975)
British Heart Foundation (FS/SBSRF/20/31005)