Chronic lung allograft dysfunction after lung transplantation: the moving target

Area of Science:

• Pulmonology
• Transplantation Immunology
• Clinical Medicine

Background:

• Chronic lung allograft dysfunction (CLAD) is a primary obstacle in long-term lung transplant recipient care.
• Both alloimmune and non-alloimmune factors contribute to CLAD development.
• The term 'chronic rejection' is often avoided by specialists but understood by patients.

Purpose of the Study:

• To delineate the different phenotypes of chronic lung allograft dysfunction.
• To characterize the clinical and pathological distinctions between these phenotypes.
• To discuss the prognostic implications and management strategies for CLAD.

Main Methods:

• Phenotypic classification of chronic lung allograft dysfunction.
• Clinical characterization of restrictive allograft syndrome (RAS) and bronchiolitis obliterans syndrome (BOS).
• Subtyping of BOS based on response to azithromycin and airway inflammation.

Main Results:

• RAS is characterized by restrictive physiology and peripheral inflammation/fibrosis.
• BOS exhibits obstructive physiology and small airway pathology.
• Neutrophilic reversible allograft dysfunction (NR-BOS) responds to azithromycin, while fibrous BOS does not.
• RAS generally has poorer survival than BOS; early-onset BOS has a worse prognosis than late-onset BOS.

Conclusions:

• CLAD encompasses diverse phenotypes with differing prognoses.
• Distinguishing between RAS and BOS subtypes is critical for patient management.
• Further research into preventive and therapeutic options for CLAD is essential.
• Early palliative care integration can improve the quality of life for lung transplant recipients experiencing CLAD.