Elevated mRNA levels of CTLA-4, FoxP3, and granzyme B in BAL, but not in blood, during acute rejection of lung allografts.
BACKGROUND
Regulatory T cells (Tregs) have been related to acute rejection as have the cytotoxic T cells, their immunological counterpart. High expression of cytotoxic markers has been related to acute rejection incidents following both kidney and intestine transplantation, while the correlation between FoxP3 expression and acute rejection is still being debated. Some studies have been performed on blood samples from lung-transplanted patients, while others have investigated the local immune response in the lungs by analysing broncho-alveolar-lavage (BAL) fluids or biopsies. Biopsies are considered the gold standard in diagnosis of acute rejection.


OBJECTIVE
The aim was to measure the expression of both Treg (FoxP3, CD25 and CTLA-4) and cytotoxic (granzyme B, granulysin, and perforin) markers in BAL and blood samples from lung-transplanted patients to investigate the possible relation of expression and acute rejection incidents in order to develop a non-invasive diagnostic method for acute rejection.


METHODS
24 lung-transplanted patients were included in this 6-month cross-section study. BAL and blood samples were analysed for FoxP3, CD25, CTLA-4, granzyme B, granulysin, perforin, CD4 and CD8 mRNA by QRT-PCR with glyceraldehyde 3-phosphate dehydrogenase (GAPDH) as primary reference.


RESULTS
We demonstrate that the mRNA levels in BAL relative to GAPDH of nearly all markers are elevated during acute rejection; CTLA-4, FoxP3, and granzyme B significantly, while a strong tendency is seen among the others. No significant differences were detected in blood.


CONCLUSIONS
CTLA-4, FoxP3 and Granzyme B mRNA levels are elevated during acute rejection in BAL, but not in blood, following lung transplantation, indicating that evaluation of Treg and cytotoxic marker expression in BAL can be used in the assessment of allograft rejection state.
Madsen
Caroline B
CB
The Tissue Type Laboratory, The University Hospital of Copenhagen, Copenhagen Ø, Denmark.
Nørgaard
Astrid
A
Iversen
Martin
M
Ryder
Lars P
LP
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry* / Q000276:immunology; D060908:CTLA-4 Antigen; D005260:Female; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism; D006084:Graft Rejection / Q000097:blood / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D053804:Granzymes / Q000235:genetics / Q000378:metabolism; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000235:genetics / Q000378:metabolism; D008168:Lung / Q000473:pathology; D016040:Lung Transplantation; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D014184:Transplantation, Homologous
D015703:Antigens, CD; D015415:Biomarkers; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D053645:Interleukin-2 Receptor alpha Subunit; D012333:RNA, Messenger; D053804:Granzymes