Exaggerated TNFalpha release of alveolar macrophages in corticosteroid resistant sarcoidosis.

BACKGROUND AND AIM OF WORK: The aim of the present study was to determine the TNFalpha release of cultured alveolar macrophages (AM) and the bronchoalveolar lavage (BAL) cellular profile in 35 patients suffering from long lasting sarcoidosis. METHODS: The AM TNFalpha release and the BAL cellular profile of 35 patients with a mean duration of sarcoidosis of 10.4 +/- 1.3 years at the time of BAL was compared to 35 healthy controls. RESULTS: The BAL profile of 12 sarcoid patients with a stable disease was similar to that known from acute sarcoidosis. Sarcoid patients with progressive disease (n = 12) and sarcoid patients with corticosteroid resistant disease (n = 11) were characterised by a normal CD4/CD8 ratio and a significant increase of BAL neutrophils (2.7 +/- 1.0% and 3.8 +/- 1.1%, respectively). The AM TNFalpha release of sarcoid patients with stable disease did not differ significantly from controls (523 +/- 124 pg/ml vs. 410 +/- 104 pg/ml). In contrast, we observed a significantly elevated TNFalpha release in sarcoid patients with progressive (2,124 +/- 550 pg/ml; p < 0.01) as well as in those with a corticosteroid resistant disease (1,585 +/- 520 pg/ml; p < 0.01) compared to controls. CONCLUSION: Chronic sarcoid patients in a progressive phase of the disease and those with a corticosteroid resistant disease are characterised by a significantly increased TNFalpha release of cultured AM. Our results support the usage of chimeric anti-TNFalpha antibodies as an alternative therapeutic regimen in chronic corticosteroid resistant sarcoidosis.

The P2Y14 receptor of airway epithelial cells: coupling to intracellular Ca2+ and IL-8 secretion.

Uridine nucleotides and UDP-glucose are endogenous molecules, which are released into the extracellular environment in a lytic manner after cell damage, as well as by regulated nonlytic mechanisms. Recently, a UDP-glucose-specific G(i) protein-coupled P2Y receptor, namely P2Y(14), has been cloned. In this study, we demonstrated expression of the P2Y(14) mRNA in human lung epithelial cells and in the epithelial cell lines A549 and BEAS-2B. Evidence of functional expression of the P2Y(14) receptor in these cell lines was provided by calcium measurements after stimulation with uridine 5'-diphosphoglucose (UDP-glc). Experiments with pertussis toxin and the Ca(2+)-chelator EGTA revealed participation of pertussis toxin-sensitive G(i/o)-proteins in the mobilization of Ca(2+)-ions from intracellular stores by UDP-glc. Moreover, UDP-glc increased secretion of the potent neutrophil chemoattractant CXCL8/IL-8 in A549 and BEAS-2B cells in a pertussis toxin-sensitive manner. Moreover, reverse transcription and quantitative polymerase chain reaction revealed that UDP-glc modulated mRNA levels of IL-8/CXCL8. However, stimulation of A549 and BEAS-2B cells with UDP-glc neither modified basal nor cytokine-induced secretion of the CXC-chemokines CXCL9/MIG, CXCL10/IP-10, and CXCL11/I-TAC. In addition, UDP-glc did not affect proliferation of the two cell lines. In summary, our data provide evidence for a distinct physiologic role of P2Y(14) in the selective release of specific chemokines from human airway epithelial cells.

Systemic immune cell activation in a subgroup of patients with idiopathic pulmonary fibrosis.

BACKGROUND: The prognosis of idiopathic pulmonary fibrosis (IPF/UIP) is poor and its immunopathogenesis is insufficiently understood. OBJECTIVES: The aim of our study was to elucidate the compartmentalization of cell activation and the influence of corticosteroid therapy upon this activation in IPF/UIP. We determined the concentrations of proinflammatory cytokines released by bronchoalveolar lavage (BAL) cells and peripheral blood mononuclear cells (PBMNC) in treated and untreated patients with IPF/UIP. We chose tumor necrosis factor-alpha (TNFalpha) since it is a cytokine predominantly secreted by cells of the monocyte/macrophage lineage and interleukin-2 (IL-2) exclusively by T lymphocytes. METHODS: The release of TNFalpha and IL-2 by BAL cells and PBMNC was measured in cell culture supernatants of 72 treated and untreated IPF/UIP patients. Additionally, in the blood compartment serological parameters reflecting the monocyte/macrophage and lymphocyte activation, such as neopterin and soluble IL-2 receptor (sIL-2R), were determined. RESULTS: The TNFalpha release by BAL cells was significantly elevated in both groups compared to controls but did not differ between treated and untreated patients with IPF/UIP. In 7 of 19 untreated patients with IPF, PBMNC were activated and released increased amounts of TNFalpha. In only 1 of 17 treated patients with IPF, TNFalpha release by PBMNC could be found. The serum level of neopterin, a marker of cell activation of the monocyte/macrophage lineage did not differ between treated and untreated patients. The BAL lymphocyte and PBMNC IL-2 release was significantly elevated in IPF/UIP patients without therapy compared to controls (p < 0.05). In contrast, no IL-2 release of BAL cells or PBMNC was observed in treated IPF/UIP patients. Lymphocyte activation was furthermore identified in untreated IPF patients by elevated soluble IL-2 receptor serum concentrations (p < 0.0001). CONCLUSIONS: Cells of the monocyte/macrophage lineage and T lymphocytes are activated in BAL cells and PBMNC of patients with IPF/UIP. During treatment, the systemic and local activation of T cells is suppressed. BAL macrophages, however, maintain their activated status, which might be the cause for the frequent chronic progression of the disease.