Blood levels of leukotrienes (LTC4, D4, E4, B4) and synthesis of leukotriene B4 by peripheral leukocytes in children with acute A and B hepatitis

Leukotrienes (LTs) are cell-membrane derived lipid inflammatory mediators, synthesized and eliminated by the liver. LTs have effects on liver cells in some pathological conditions. In this study, we measured plasma endogenous and liberated leukotriene (LT) concentration in peripheral blood leukocytes stimulated in vitro by the calcium ionophore (CaA23187) and platelet-activating factor (PAF). Production of LTs was measured in type A (n=37) and type B (n=10) acute hepatitis patients and control subjects (n=10). LTs levels were measured by high performance liquid chromatography (HPLC) and radioimmunoassay (RIA). The concentration of LTB4 measured in plasma and stimulated peripheral blood leukocyte supernatants of children with hepatitis A infection was found to be statistically elevated and in positive correlation with serum alanine aminotransferase (ALT) levels. In plasma samples of hepatitis B patients, LTC4 and LTE4 were measured in significantly elevated concentrations. These results suggest that LTB4 may be a critical mediator of hepatitis A virus-induced hepatocellular injury.

Sublingual immunotherapy and influence on urinary leukotrienes in seasonal pediatric allergy

Sublingual immunotherapy has been suggested for the treatment of respiratory allergies. Many controversial studies have been reported on the efficacy of sublingual immunotherapy. The aim of this prospective study was to evaluate whether sublingual immunotherapy was effective according to clinical and laboratory results in pediatric allergies. Thirty-nine allergic, grass pollen sensitive children were admitted into the study. Sublingual immunotherapy was given over a 12-month period to 21 children (mean age 10.5 +/- 3.3 years), 10 of whom had seasonal allergic rhinitis and 11 seasonal allergic asthma. During the same period, 18 children (mean age 11.1 +/- 2.5 years), 10 with seasonal allergic rhinitis and eight with seasonal allergic asthma, received placebo. Symptom scores and drug requirements were recorded and urine samples were collected to detect urinary levels of leukotrienes (Uc-LTB4 and Uc-LTE4). In patients who received sublingual immunotherapy, the symptom scores of seasonal allergic rhinitis significantly decreased, but no statistically significant changes were observed in terms of symptoms of seasonal allergic asthma. Uc-LTE4 and Uc-LTB4 levels of seasonal allergic rhinitis, with a geometric mean and 95% confidence interval (CI), were significantly decreased from 216 (103-464) and 61 (22-198) pmol/mmol creatinine to 78 (29-159) and 35 (12-118) pmol/mmol creatinine, respectively (p < 0.05 and p < 0.05). On the other hand, Uc-LTE4 and Uc-LTB4 levels for seasonal allergic asthma were 180 (92-355) and 78 (44-258) pmol/mmol creatinine and decreased to 156 (72-402) and 69 (32-254) pmol/mmol creatinine, respectively. These changes were not statistically significant (p > 0.05). According to our clinical results and urinary levels of leukotrienes, which are mediators showing the severity of allergic inflammation, it can be suggested that sublingual immunotherapy may be useful in the treatment of seasonal allergic rhinitis but not of seasonal allergic asthma.

Increased gastric juice leukotriene B4, C4 and E4 concentrations in children with Helicobacter pylori colonization

During recent years, the role of inflammatory lipid mediators in the pathophysiology of Helicobacter pylori (H. pylori) infections has been investigated in several studies. The concentrations of leukotrienes (LTs) in gastric juice from H. pylori positive (n = 13) and negative (n = 18) children with recurrent abdominal pain were studies in order to determine whether these lipid inflammatory mediators are involved in local and systemic biological actions. Gastric juice samples and biopsy specimens of mucosa were obtained endoscopically from 31 patients with recurrent abdominal pain for assessment of LTs and histopathological examination. In this study, all children with recurrent abdominal pain were investigated by rapid urease test and histological assessment for H. pylori colonization. Leukotriene levels were measured by high performance liquid chromatography (HPLC) and radioimmunoassay (RIA) in gastric juice samples. Gastric juice LTB4, LTC4, and LT4 levels were significantly higher in patients with H. pylori colonization than in children without H. pylori colonization. These results indicate that increased gastric content of proinflammatory mediators (LTB4, LTC4, and LT4) may be related to the pathogenesis of H. pylori-associated gastritis.

The role of PAF and leukotrienes in bioincompatibility of cuprophane membranes in hemodialysis

Inflammatory lipid mediators, PAF and leukotrienes (LTs), are thought to have an important role in biocompatibility in hemodialysis. PAF, LTB4 and LTC4 were studied both in controls (n: 12) and in 11 children on regular hemodialysis (150 minutes) with cuprophane dialyzers. Blood samples were collected initially (0'-precapillary), at first minute (1'-postcapillary) and at one hour after the hemodialysis sessions (210'-venous). Presence of LTs and high levels of PAF in 0' samples compared to levels in controls and significant increases in 1' samples suggested the alterations in PAF and LTs likely originated from the peripheral leukocyte activation. In 210' samples, PAF and LTs levels were decreased but still higher than the levels in 0' samples. This study suggested that PAF and LTB4 may be the control elements in biocompatibility in hemodialysis with cuprophane membranes, and demonstrated that the effects of activation last until the following session.