Increasing evidence suggests an important role for cytokines in the regulation of eosinophilic inflammation. In the present study we investigated the distribution of leukocytes, lymphocyte subsets, their activation state, and the cytokine profile present in BAL fluid from patients with various lung diseases associated with eosinophilia. For this purpose, we analyzed the levels of IL-1 beta, IL-2, IL-4, IL-5, IL-6, IL-8, GM-CSF, TNF-alpha, and IFN-gamma, as well as soluble IL-2 and TNF receptors, in concentrated bronchoalveolar lavage (BAL) fluid obtained from clearly defined patients with allergic and nonallergic asthma, eosinophilic pneumonia, allergic bronchopulmonary aspergillosis (ABPA), hypersensitivity pneumonitis, and idiopathic pulmonary fibrosis. BAL fluid from normal individuals and sarcoidosis patients was analyzed as noneosinophilic controls. BAL cytokine levels were compared with the cellular infiltrate and the activation state of CD4+ and CD8+ T cells as measured by the expression of IL-2 receptors (CD25), HLA-DR, and the very late activation antigen VLA-1. Beside the characteristic leukocyte infiltrate in the various lung diseases, all patients demonstrated significantly increased numbers of activated CD4 and CD8 T cells compared with normal individuals. The analysis of the cytokine profile present in BAL fluid revealed a T helper type 2 (Th2) cell cytokine pattern, with elevated IL-4 and IL-5 but normal levels of IL-2 or IFN-gamma in allergic asthma. ABPA patients demonstrated significantly increased levels of IL-4 and IL-5, with low but significantly elevated concentrations of IL-2 and IFN-gamma. In contrast, the analysis of the cytokine profile in sarcoidosis patients revealed a Th1 cell cytokine pattern characterized by increased concentrations of IL-2 and IFN-gamma but normal levels of IL-4 or IL-5. All other patient groups showed a cytokine pattern incompatible with a pure Th1 or Th2 cell response, because IL-5, IL-2, and IFN-gamma were found to be significantly increased. The BAL fluid analysis of the other, mainly non-T cell-derived cytokines and soluble receptors showed increased levels in all patients compared with normal individuals and may represent the ongoing inflammatory responses. In conclusion, whereas increased IL-4 levels were found only in diseases characterized by increased IgE production, IL-5 was elevated in all patients with increased numbers of eosinophils. The close correlation between IL-5 levels, number of eosinophils, and activated T cells further supports a role for IL-5 in causing tissue eosinophilia.

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One hundred and seventy-two competitors of the Swiss Alpine Marathon, Davos, Switzerland, 1988, volunteered for this research project. Of these volunteers 170 (158 men, 12 women) finished the race (99%). The race length was 67 km with an altitude difference of 1,900 m between the highest and lowest points. Mean age was 39 (SEM 0.8) years. Average finishing times were 8 h 18 min (men) and 8 h 56 min (women). Loss of body mass averaged 3.4% body mass [mean 3.3 (SEM 0.2)%; 4.0 (SEM 0.4)%; men and women, respectively]. Blood samples from a subgroup of 89 subjects (6 women and 83 men) were taken prior to and immediately after completion of the race. Changes in haemoglobin (9.3 mmol.l-1 pre-race, 9.7 mmol.l-1 post-race) and packed cell volume (0.44 pre, 0.48 post-race) were in line with the moderate level of dehydration displayed by changes in body mass. Mean plasma volume decreased by 8.3%. No significant changes in plasma osmolality, sodium, or chloride were observed but plasma potassium did increase by 5% (4.2 mmol.l-1 pre-race, 4.4 mmol.l-1 post-race). Mean fluid consumption was 3290 (SEM 103) ml. Forty-three percent of all subjects, and 33% of those who gave blood samples, complained of gastro-intestinal (GI) distress during the race. No direct relationship was found between the quantity or quality of beverage consumed and the prevalence of GI symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

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Human pulmonary alveolar macrophages synthesized and secreted several characteristic high molecular weight proteins for at least 7 d in vitro. Immunoprecipitates of medium and cell lysates from metabolically labeled cultures with specific anti-human plasma fibronectin IgG contained one major labeled polypeptide of molecular weight 440,000 (unreduced) or 220,000 (reduced) . An identical polypeptide in conditioned medium from radiolabeled macrophages bound specifically to gelatin-Sepharose, demonstrating that alveolar macrophages synthesized and secreted a molecule immunologically and functionally similar to fibronectin . Fibronectin was the major newly synthesized and secreted polypeptide of freshly harvested alveolar macrophages. Pulse-chase experiments revealed that newly synthesized fibronectin was rapidly secreted into medium, -50% appearing by 1 h and 80% by 8 h. Immunoperoxidase staining using antifibronectin F(ab') 2-peroxidase conjugates revealed the majority of immunoreactive fibronectin to be intracellular, localized to endoplasmic reticulum and Golgi apparatus. No extracellular matrix fibronectin was visualized, and cell surface staining was rarely seen, usually appearing only at sites where cells were closely apposed and not at sites of macrophage-substrate attachment. Similar immunostaining of fibroblast cultures revealed cell surface-associated fibrillarfibronectin . Ultrastructural localization of fibronectin during binding and phagocytosis of gelatin-coated and plain latex particles revealed fibronectin only on gelatin-latex beads and at their cell binding sites. Neither plain latex beads nor their cell membrane binding sites stained for fibronectin . These results demonstrate that fibronectin is a major product of human alveolar macrophages, is rapidly secreted, and is localized at cell membrane binding sites for gelatin-coated particles. In view of the known binding properties of fibronectin, it may serve as an endogenous opsonic factor promoting the binding of Staphylococcus, denatured collagen, fibrin, or other macromolecules to macrophages in the lower respiratory tract. In the lung, alveolar macrophages (PAM) play a key role in the uptake of particulate debris and microorganisms from the terminal airways and alveoli (14). However, unlike blood monocytes and peritoneal macrophages, PAM residing in their