TNF-ALPHA MESSENGER-RNA, BUT NOT IL-1-BETA, IS DIFFERENTIALLY EXPRESSED IN LUNG MACROPHAGES OF PATIENTS WITH ACTIVE PULMONARY SARCOIDOSIS

In pulmonary sarcoidosis or experimental granuloma formation, interleu kin-1beta(IL-1beta) or tumor necrosis factor alpha(TNFalpha) seem to p lay important roles during the inflammatory process. In order to exami ne whether IL-1beta or TNFalpha mRNA expression in lung macrophages re lates to disease activity or clinical course, ten cases with pulmonary sarcoidosis were divided into two groups: five cases with disease dur ation of more than 10 years (14.6+/-4.4 yrs; group A), and 5 cases wit h a duration of less than 3 years (1.7+/-1.1 yrs; group B). All cases showed both abnormal chest X-rays and elevated serum angiotensin conve rting enzyme activities. We compared these ten cases with 12 healthy s ubjects (6 nonsmokers: NS and 6 current smokers: S), and 5 cases with idiopathic pulmonary fibrosis (IPF) as disease control. Lavage macroph ages were purified using the rosette forming method followed by plasti c adhesion for one hour. Thereafter, RNA was extracted according to th e AGPC method and amplified by the reverse transcription-polymerase ch ain reaction (RT-PCR). The results showed that IL-1beta mRNA was detec ted in all samples studied, but TNFalpha mRNA expression was different among the groups: 5/5 (100%) in group A, 1/5 (20%) in group B, 5/5 (1 00%) in IPF, and 12/12 (100%) in healthy subjects. A constitutive expr ession was seen in healthy controls. On the other hand, no detection o f TNFalpha mRNA was shown in pulmonary sarcoidosis. This fact may rela te to a spontaneous regression of inflammation in sarcoidosis, as a su bstantial number of cases in group B may in time regress spontaneously .