The value of interleukin-12 as an activity marker of pulmonary sarcoidosis.
BACKGROUND
Sarcoidosis is characterized by hyperactivity of T-helper lymphocytes and recent studies showed that they were mainly Th1 cells. IL-12 is a major cytokine inducing Th1 differentiation of naive T cells. This study was performed to test whether IL-12 can be a marker for disease activity and possibly a prognosis in sarcoidosis.


METHODS
IL-12 levels of BALF (BALF-IL-12) and conditioned medium of alveolar macrophages (AM) were measured by ELISA in 36 patients with pulmonary sarcoidosis (14 males and 22 females, mean age: 39.6 +/- 11.0 years) and eleven normal controls. Clinically, 16 patients had active sarcoidosis and 20 had an inactive disease.


RESULTS
BALF-IL-12 of sarcoidosis patients (41.3 +/- 43.9 pg/ml) was significantly higher than that of normal controls (2.5 +/- 0.4 pg/ml) (p < 0.001). The patients with active disease (71.3 +/- 54.3 pg/ml) had a higher BAL-IL-12 level than those with inactive disease (17.3 +/- 13.8 pg/ml) (p = 0.0001). It had a significant correlation with the number of T4 cells (p = 0.0001), total cell number, number and percentage of lymphocytes (p = 0.0001) and AM (p = 0.001) in BALF. It was also significantly correlated with soluble ICAM-1 levels in serum (p = 0.0001) and BALF (p = 0.002), and ICAM-1 expression of AM (p = 0.001). Furthermore the patients whose condition worsened without therapy had a significantly higher initial BALF-IL-12 level than the patients whose condition improved spontaneously. The AM of sarcoidosis secreted significantly more IL-12 (133 +/- 177 pg/ml) than AM of controls (68.3 +/- 43.7 pg/ml) (p = 0.038).


CONCLUSIONS
Our data suggest that the BALF-IL-12 level can be used as a marker of the activity of pulmonary sarcoidosis and possibly prognosis.
Kim
D S
DS
Department of Pulmonary Medicine, Asan Medical Center, University of Ulsan, School of Medicine, Seoul, Korea. dskim@www.amc.seoul.kr
Jeon
Y G
YG
Shim
T S
TS
Lim
C M
CM
Lee
S D
SD
Koh
Y
Y
Kim
W S
WS
Kim
W D
WD
D000328:Adult; D015415:Biomarkers / Q000097:blood; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000097:blood*; D018664:Interleukin-12 / Q000097:blood*; D016676:Macrophages, Alveolar / Q000737:chemistry; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012016:Reference Values; D017565:Sarcoidosis, Pulmonary / Q000097:blood* / Q000175:diagnosis; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric
D015415:Biomarkers; D018799:Intercellular Adhesion Molecule-1; D018664:Interleukin-12