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Updated: May 26, 2026
Development of Obliterative Bronchiolitis in a Murine Model of Orthotopic Lung Transplantation
Published on: July 10, 2012
Bronchoalveolar lavage for supporting acute cellular rejection in lung transplant recipients: A retrospective
Carolin Steinack1,2, Anna Hillinger1,2, Jan H Rüschoff3
1Department of Pulmonology, University Hospital Zurich, Zurich, Switzerland.
Insights
Bronchoalveolar lavage (BAL) lymphocytosis aids in early detection of acute cellular rejection (ACR) in lung transplant recipients. BAL cytology offers accuracy for ACR surveillance, complementing traditional biopsies.
Area of Science:
- Pulmonary Medicine
- Transplant Surgery
- Diagnostic Cytology
Background:
- Early detection of acute cellular rejection (ACR) is crucial for lung transplant recipients (LTRs).
- Transbronchial biopsies are standard, but bronchoalveolar lavage (BAL) offers a less invasive alternative.
- This study evaluates BAL's cytological and microbiological features for ACR detection.
Purpose of the Study:
- To assess the correlation between BAL findings and ACR diagnosed by transbronchial cryobiopsy.
- To compare pathology and hematology methods for BAL sample analysis.
- To determine the value of mucosal biopsies for ACR detection.
Main Methods:
- Retrospective analysis of transbronchial biopsies and BALs from 143 LTRs (January 2020 - March 2024).
- ACR diagnosis based on ISHLT histopathological criteria using cryobiopsy.
- Mixed-effects analysis to assess associations between BAL parameters and ACR.
Main Results:
- ACR was diagnosed in 17.9% of procedures.
- Microbiological findings and mucosal biopsies were not associated with ACR.
- BAL relative lymphocyte counts (median 3%) significantly correlated with ACR (OR 1.07, p=0.004) and severity (r=0.385, p<0.001).
- A lymphocyte threshold of 5.7% yielded an ROC AUC of 0.715.
Conclusions:
- BAL lymphocytosis can support the diagnostic process for ACR in LTRs.
- BAL cytology, particularly microscopic assessment, provides relevant accuracy for ACR detection.
- Incorporating BAL lymphocyte analysis into routine surveillance may improve early ACR detection.
Background:
Early detection of acute cellular rejection (ACR) is vital for improving long-term outcomes in lung transplant recipients (LTRs). Transbronchial biopsies are the gold standard for diagnosing ACR, but bronchoalveolar lavage (BAL) offers a less invasive alternative for early detection. This study examines the cytological and microbiological features of BAL, its correlation with ACR diagnosed via transbronchial cryobiopsy, and compares the effectiveness of pathology and hematology methods in analyzing BAL samples. Additionally, it assesses the value of mucosal biopsies for ACR detection.
Methods:
Transbronchial biopsies and corresponding BALs from January 2020 to March 2024 were analyzed retrospectively. ACR was diagnosed using cryobiopsy according to ISHLT histopathological criteria. Associations between BAL parameters and ACR were assessed using mixed-effects analysis.
Results:
Among 240 procedures from 143 LTR, 17.9% were diagnosed with ACR. Microbiological findings and mucosal biopsy analyses were not associated with ACR. In contrast, the relative lymphocyte counts in BAL (median 3% [IQR 2-5%]) was significantly associated with ACR (OR 1.07 [95% CI 1.02-1.12], p=0.004). A significant correlation between lymphocyte proportion and ACR severity was observed (r=0.385, p<0.001). A threshold of 5.7% lymphocytes achieved an ROC AUC of 0.715 (95% CI 0.613-0.817), with a positive predictive value of 66.7% and a negative predictive value of 76.5%.
Conclusion:
BAL lymphocytosis could support the diagnostic process of ACR. While mucosal biopsies and microbiological testing did not aid in ACR detection, BAL cytology provided relevant accuracy, particularly when assessed microscopically. These findings support incorporating BAL lymphocyte analysis into routine surveillance strategies for early ACR.
