Comparison of hormone transfer to pleural and synovial exudates

Local effects of hormones on immune and connective tissues could play some role in the development of local inflammation processes. The aim of this study was to investigate the levels of selected hormones in pleural exudates of patients with pleurisy and lung tumours, and compare these levels with hormone concentration in knee synovial fluid.

Eleven patients with pleural exudate (mean age 62+/-3) and l9 subjects with rheumatoid arthritis (of the same mean age) participated in the observations. Plasma, pleural exudates and synovial fluid levels of cortisol, prolactin, aldosterone, testosterone, 17-beta-estradiol, dehydroepiandrosterone, progesterone, insulin and C-peptide were determined by specific radioimmunoassay.

It was noted that all estimated hormones are transferred into pleural exudates and synovial fluid. Higher levels of dehydroepiandrosterone and C-peptide were observed in pleural exudates as compared to plasma. The concentrations of testosterone, prolactin and estradiol in males were lower in exudates as compared to plasma. Mean levels of cortisol, aldosterone, progesterone and insulin in plasma were similar to these found in pleural exudates. The comparison of hormone levels in pleural exudates and synovial fluid showed that the levels of cortisol, progesterone and dehydroepiandrosterone tended to be higher in the exudates as compared to synovial fluid. However, the levels of insulin, testosterone and estradiol in exudates were lower than these in inflammatory synovial fluid from patients with rheumatoid arthritis.

This study showed the presence of hormones in pleural exudates. The differences in hormone concentrations in pleural exudates and synovial fluid were observed suggesting a specificity of hormone transfer from plasma to these exudates.