Introduction: Severe acute rejection (AR) after lung transplantation (LT) increases the risk of bronchiolitis obliterans syndrome with subsequent impairment in patient and graft survival. The identification of biomarkers to minimize AR rate and improve long term graft survival should be a priority in transplant field. Previously, the CD8 effector memory T (TEM) cells have been identified as a potential biomarker of acute rejection in patient awaiting for a lung transplantation(1). The aim of the study was to correlate CD8 TEM with severity of acute rejection after LT.
Material and Methods: 76 patients with end-stage lung disease were recruited from 2010 in our institution and prospectively followed after LT. Flow cytometry and monoclonal antibodies to identify CD8 T cell subsets in peripheral blood were used. Protocol biopsy at 21 day post transplantation was performed to identify acute rejection.
Results and discussion: A total of 41 (54%) of LT recipients had acute rejection and 9 of them were severe (grade A3 or A4). Before transplant, the patients with severe acute rejection had significantly higher CD8 TEM/mm³ than no AR group (median 328.5; IQR: 187.2-507.6) vs (median 70.2; IQR: 49.3-123.8); p=0.027, whereas the levels of CD8 TEM in mild AR group are reduced compared with severe AR (median 95.4; IQR: 45.8 – 189.8); p=0.0748. The CD8 TEM levels pre-LT are increased in those with subsequent severe AR.
Conclusion: Monitoring the levels of CD8 TEM prior lung transplantation could identify patients at risk of suffering severe acute rejection. This biomarker should be validated in larger multicentre studies before be used in clinic.
Reference: San Segundo, D et al. PLoS One. 2013 Nov 13;8(11):e80601