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.
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.
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.
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.