IgG4-related interstitial lung disease: a new and evolving concept

Area of Science:

• Pulmonology
• Immunology
• Pathology

Background:

• Immunoglobulin G4-related disease (IgG4-RD) is an evolving fibroinflammatory condition.
• IgG4-related interstitial lung disease (IgG4-ILD) is a newly recognized manifestation of IgG4-RD.
• Understanding the clinical, pathological, diagnostic, and therapeutic aspects of IgG4-ILD is crucial.

Purpose of the Study:

• To review recent advances in the understanding of IgG4-related interstitial lung disease (ILD).
• To examine the clinical, pathological, diagnostic, and therapeutic features of IgG4-ILD.
• To synthesize current knowledge on this emerging lung disorder.

Main Methods:

• Literature review of recent studies on IgG4-related interstitial lung disease.
• Analysis of case series and retrospective studies.
• Examination of diagnostic criteria and imaging findings.

Main Results:

• A case series suggested IgG4-ILD can resemble lymphomatoid granulomatosis, with IgG4-positive plasma cells being key.
• Pulmonary involvement was observed in patients with autoimmune pancreatitis, with elevated IgG4 and Krebs von den Lungen-6 levels potentially predictive.
• Radiological and pathological analyses identified specific computed tomographic features of IgG4-related sclerosing inflammation in the lung interstitium.

Conclusions:

• IgG4-related ILD is an emerging and evolving clinical entity.
• This lung disease can manifest independently or alongside systemic IgG4-related disease.
• Further large-scale studies are needed to fully understand the mechanisms and clinical spectrum of IgG4-ILD.