Background: Despite of morphologic differences between non-rejection (0 due to ISHLT scale) and moderate focal cellular rejection (1a, ISHLT) i.e.  lymphocytes aggregation, the genetic and clinical differences in CARGO studies were not shown. Therefore the aim of the study was to compare the expression of selected antigens associated with apoptosis in heart transplant (HTx) recipients in the context of 0 and 1a cellular rejection. The expression of Annexin V, Bcl-2 (protective apoptotic activity), Bcl-xL (antiapoptotic activity) and Bcl-xS/L (other antiapoptotic mechanism) were assessed.
Material/Methods: 17 heart transplant patients were retrospectively included  into the trial (2 women and 15 men, mean age 46.2±13.9 yr, BMI 25.7±3.2). 10 biopsies presented rejection 0 and next 10-1a (due to ISHLT scale) - group A and B, respectively. Endomyocardial biopsy specimens were processed using routine immunohistochemical method. The frozen sections were incubated with adequate anti-human antibodies from BioVision and Santa Cruz Biotechnology. The expression was assessed according to IHC method i.e. 0 - the lack of expression, 1 - trace, 2 - distinct and 3 - strong. The correlation was analyzed between particular molecules expression. Results: The significant increase of Bcl-2 expression together with rejection was observed. The expression of other antigens was also shown but without signs of any significant tendency. No correlation in group A was noted, on the contrary, in group B the significant strong and negative correlation between Bcl-2 and Bcl-xS/L was revealed.
Conclusions: Bcl-2 expression responds to the morphologic progression of
graft rejection and is opposing to Bcl-xS/L activity.

Keywords: Heart Transplantation