Optical Biopsies Using Probe-Based Confocal Laser Endomicroscopy for Autoimmune Pulmonary Alveolar Proteinosis

Area of Science:

• Pulmonology
• Medical Imaging
• Pathology

Background:

• Mild pulmonary alveolar proteinosis (PAP) diagnosis is challenging due to patchy lesions and limited biopsy samples.
• Pathological differences between mild and severe PAP require further elucidation.
• Increased chest CT use reveals more mild, asymptomatic PAP cases.

Purpose of the Study:

• To clarify pathological findings in mild PAP.
• To assess the diagnostic utility of optical biopsy using probe-based confocal laser endomicroscopy (pCLE).

Main Methods:

• Bronchoscopic optical biopsy with pCLE and tissue biopsy were performed on 5 PAP patients (3 mild, 2 severe).
• pCLE images were compared between mild and severe PAP, integrating clinical, pathological, and CT data.

Main Results:

• pCLE revealed giant cells, amorphous substances, and thin alveolar walls in PAP.
• Affected lesions in mild PAP showed pCLE images similar to severe PAP.
• Mild PAP cases showed spontaneous improvement or stability; all patients had anti-GM-CSF antibodies.

Conclusions:

• pCLE optical biopsy provides specific diagnostic findings for mild PAP.
• Similar pCLE findings in mild and severe PAP suggest comparable alveolar macrophage dysfunction levels.