Discrepancy between mRNA expression and production of IL-2 and IL-4 by cultured graft infiltrating cells propagated from endomyocardial biopsies.

We studied whether acute rejection correlated with the cytokine production pattern and mRNA expression of interleukin-2 (IL-2) and interleukin-4 (IL-4) in lymphocyte cultures derived from endomyocardial biopsies (EMB) that were stimulated with B cell lines of donor origin. Unstimulated biopsy cultures neither expressed mRNA nor produced IL-2 or IL-4. All stimulated biopsy cultures contained mRNA transcripts for IL-2 and IL-4. In contrast, we found different IL-2 and IL-4 production patterns. Within the first 90 days after heart transplantation (HTx), higher levels of IL-4 were measured in cultures derived from EMB with myocytolysis than in cultures from EMB without signs of myocytolysis. More than 90 days after HTx, this phenomenon was reversed and more IL-4 was produced in cultures derived from EMB without myocytolysis. These differences were not detected for IL-2 production.