1Ayoub AA, 1El–Sayed
SA, 1Soad E. Abdel Rehim, 3Abu Naglah A. and
2Abu El-Eneen SS
Departments
of 1Microbiology and 2Internal Medicine, Faculty of
Medicine for Girls, Al-Azhar University and 3Chest Department,
Faculty of Medicine, Al-Azhar University, Cairo, Egypt.
Interleukin-6 (IL-6) is a
multifunctional cytokine whose abnormal production was previously reported in
pleural effusion. The clinical significance of soluble IL-6 receptors (sIL-6R)
in pleural effusion is still not understood. In the present study, IL-6 and
sIL-6R were measured using ELISA in exudative pleural effusion of tuberculous,
malignant and postpneumonic origins and in transudative effusion secondary to
heart failure, liver cirrhosis and nephropathy, to determine their diagnostic
value and whether either or both could be helpful for differential diagnosis.
Both IL-6 and sIL-6R were detectable in all pleural effusion with significantly
higher levels in exudative compared to transudative effusion. Non significant
differences in IL-6 levels were detected between exudative effusion of
different origins while levels of sIL-6R were significantly higher in malignant
and postpneumonic effusion compared to tuberculous effusion (P< 0.001,
<0.001 respectively). Nonsignificant differences were observed between
levels in effusion due to mesothelioma compared to levels in effusion due to
metastasis. It was striking in this study to observe significant differences in
levels of IL-6 and sIL-6R in tuberculous effusion collected from patients who
did not start antituberculous treatment compared to those who started treatment
(P< 0.001, <0.001 respectively). It is concluded that IL-6 and
sIL-6R levels in pleural fluids are sensitive parameters to differentiate
exudates from transudates and that sIL-6R can differentiate between exudative
effusion of different origins.