Intrapulmonary Autoantibodies to HSP72 Are Associated with Improved Outcomes in IPF

Area of Science:

• Immunology
• Pulmonology
• Pathogenesis of Fibrotic Lung Disease

Background:

• Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease with unknown causes.
• Both innate and adaptive immune responses are implicated in IPF pathogenesis.
• Heat shock proteins (Hsp) and anti-Hsp antibodies are potential therapeutic targets and prognostic biomarkers in IPF.

Purpose of the Study:

• To investigate the relationship between Hsp72 expression, anti-Hsp72 antibodies, and disease progression in IPF patients.
• To determine the prognostic value of anti-Hsp72 antibodies in IPF.
• To explore the role of anti-Hsp72 antibodies in the immune response within the lungs.

Main Methods:

• Developed a novel indirect ELISA for anti-Hsp72 IgG detection.
• Measured Hsp72 antigen, anti-Hsp72 IgG, IgGAM, and total immunoglobulin in serum and bronchoalveolar lavage fluid (BALf) from IPF and other interstitial lung disease (ILD) patients.
• Utilized immunohistochemistry to detect Hsp72 in lung tissue and measured cytokine expression from macrophages.

Main Results:

• Anti-Hsp72 IgG was detected in the serum and BALf of IPF and ILD patients.
• IPF patients showed an excessive adaptive immune response in BALf compared to other ILDs and healthy controls.
• Higher concentrations of anti-Hsp72 antibodies in BALf were associated with improved patient survival (adjusted HR 0.62, p = 0.003).

Conclusions:

• Intrapulmonary anti-Hsp72 antibodies are associated with better outcomes in IPF.
• These antibodies may be natural autoantibodies contributing beneficially to IPF pathogenesis.
• Further research is needed to elucidate the exact mechanism of action for anti-Hsp72 antibodies in IPF.