ABSTRACT
To study the nature of endotoxin or lipopolysaccharide (LPS) induced inflammation, we developed a method of quantifying intracellular human neutrophil elastase (HNE) in lysed sputum polymorphs as a means to study the degranulation status of LPS-recruited neutrophils. Induced sputum, blood and exhaled nitric oxide (NO) were collected from 10 healthy non-atopic human subjects after inhaling a single 15 microg dose of Escherichia coil LPS in an open study. At 6 hours, LPS inhalation caused significant increase of sputum and blood neutrophils but without parallel increase in myeloperoxidase, HNE or interleukin-8 (IL-8) in sputum sol and blood, or exhaled NO. Intracellular HNE in lysed sputum polymorphs or purified blood neutrophils did not show any significant changes between inhaled LPS and saline, nor was there any appreciable change in percentage HNE release induced by N-Formyl-Met-Leu-Phe (fMLP) in vitro. We concluded that in healthy humans, the transient neutrophilic inflammation induced by a single dose of inhaled 15 microg LPS is mainly characterized by cell recruitment, not enhanced secretion of granular mediators or increased exhaled NO based on our experimental conditions.
Subject(s)
Administration, Inhalation , Adult , Cell Degranulation/drug effects , Cell Movement , Cytological Techniques/methods , Endotoxins/administration & dosage , Escherichia coli , Humans , Inflammation , Leukocyte Elastase/analysis , Lipopolysaccharides/administration & dosage , Male , Neutrophils/drug effects , Nitric Oxide/analysis , SputumABSTRACT
BACKGROUND: The presence of leukocytes, detected by peroxidase test in semen, can be a good indicator of infections in the male genital tract. Peroxidase positive cells have been positively correlated with elevated values of elastase, one of the major proteases liberated by granulocytes at the inflammation place. However, seminal granulocytes may not be adequately detected by the peroxidase test in comparison with immunological methods. AIM: To correlate the determination of peroxidase positive cells with the elastase level in the seminal plasma. MATERIAL AND METHODS: Seminal plasma from 64 patients with a high number of round cells (> 106/ml) in semen, was studied. Correlation analysis was done using the Pearson correlation coefficient. RESULTS: No correlation between the level of granulocyte elastase and the number of peroxidase positive cells (r = 0.2237, p > 0.05), or even the number of round cells (r = 0.03934, p > 0.05) was observed. CONCLUSIONS: Our results suggest that the determination of peroxidase positive cells is not a reliable indicator of leukocytes in the seminal plasma and their absence do not discard a silent genital tract infection.