Definitions and prognosis of ALAD and BLAD are not settled

Summary

A 2025 review for ISHLT expert groups states that the definitions and real significance of acute lung allograft dysfunction (ALAD) and baseline lung allograft dysfunction (BLAD) are not yet fully established and many uncertainties remain. Mechanistic studies of ALAD are small: a single-cell pilot included 20 participants across four groups, and a lavage mass cytometry study found CD4+CD57+PD1+ T cells predicted ALAD, CLAD and death. An earlier lavage sequencing study of 45 recipients separated ALAD with later decline from ALAD that recovered. ISHLT consensus documents on ALAD and on BLAD were published in 2026 but only their titles are indexed in PubMed, so they could not be read for this record.

Details

barrier type

definition

Sources and links

• The ABC of transplant: ALAD, BLAD, CLAD (DOI) (primary)
• Persistent and progressive ALAD, single-cell pilot (DOI)
• Senescent CD4 T cells before failure (DOI)

Related

Links from this record

• evidence: The ABC of transplant: ALAD, BLAD, and CLAD: definition and significance
• evidence: Persistent and progressive acute lung allograft dysfunction is linked to cell compositional and transcriptional changes in small airways
• evidence: Emergence of a senescent and inflammatory pulmonary CD4+ T cell population prior to lung allograft failure
• evidence: Macrophage and CD8 T cell discordance are associated with acute lung allograft dysfunction progression
• affects: Acute lung allograft dysfunction (ALAD)
• affects: Molecular endotypes of CLAD (proposed framework)
• affects: Airway transcriptomic signatures

Known gaps in this record

• content of the 2026 ISHLT consensus documents on ALAD and BLAD (abstracts not indexed; not read)
• validated ALAD criteria and timing