Activation of macrophages and cytotoxic cells during cytomegalovirus pneumonia complicating lung transplantations.

The functional status of immune cells within human transplanted lungs was analyzed during cytomegalovirus (CMV) pneumonia complicating lung and heart-lung transplantations. The expression of interleukin-1 beta (IL-1 beta) and interleukin-6 (IL-6) genes is a marker for the activation of macrophages as is that of serine esterase B (SE-B) gene for cytotoxic cells. The levels of expression of these genes by bronchoalveolar lavage (BAL) cells were determined by in situ hybridization. Eight cases of CMV pneumonia were included in this study. BAL cells from either rejection episodes (eight cases) or control transplanted patients experiencing neither infection nor allograft rejection (eight cases) were analyzed in parallel. In the control patients, virtually no cells expressed the IL-1 beta, the IL-6, or the SE-B genes. In contrast, these three genes were all expressed in samples from patients with CMV pneumonia. IL-1 beta gene-expressing cells were abundant in all infected patients (mean +/- SEM: 898 +/- 449 positive cells per 10(4) cells, p less than 0.001, compared with those in control patients). IL-6 gene-expressing cells were less numerous (92 +/- 74 positive cells per 10(4) cells) and present in five of the eight cases of CMV pneumonia. Activated cytotoxic cells were detected in seven of the eight cases of CMV pneumonia (36.5 +/- 19 SE-B gene-expressing cells per 10(4) cells, p less than 0.001). During allograft rejections (eight cases) IL-1 beta gene-expressing cells were present in all but one patient.(ABSTRACT TRUNCATED AT 250 WORDS)