[LTB4-metabolism and histamine liberation by granulocytes in the disease pattern of cystic fibrosis (CF)]. / LTB4-Metabolismus und Histaminfreisetzung durch Granulozyten im Krankheitsbild der zystischen Fibrose (CF).

We determined the generation and liberation of LTB4 in peripheral granulocytes and the histamine release from basophils in patients suffering from cystic fibrosis (CF, median 17.2 years of age, n = 12). We compared the data with an age matched group of healthy donors (n = 12). All patients suffered from an exacerbation of a chronic pulmonary infection caused by P. aeruginosa. Peripheral granulocytes were stimulated at different days before, during and after antiinfectious treatment with Ca-Ionophore, opsonized zymosan and arachidonic acid. The granulocytes from patients with CF as compared to the control group showed an increased omega-Oxidation of the synthesized LTB4 into 20-COOH- and 20-OH-LTB4 after stimulation with Ca-Ionophore and opsonized zymosan (Ca-Ionophore: ratio of LTB4 versus omega-oxidated products (CF): 0.77 +/- 0.007 mean +/- S.E.M., n = 12, control group: 1.07 +/- 0.1, n = 12, p less than 0.01). Stimulation of the cells with Ca-Ionophore combined with arachidonic acid led to a significantly increased formation of lipoxygenase products in the patient group. No significant differences in the basophil counts were determined between both populations. However, the absolute histamine content per basophil was elevated in the CF group (2.4 +/- 0.3 versus 1.6 +/- 0.2 mean +/- S.E.M., n = 12/12, p less than 0.04). Stimulation of basophils with Ca-Ionophore and anti-IgE leads to a significant higher release of histamine per basophil in CF patients (Ca-Ionophore: 2.6 +/- 0.2 versus 1.3 +/- 0.8 pg/basophil, mean +/- S.E.M., p less than 0.05). These data indicate that basophils in CF may have a greater potential to release mediators. During the antiinfectious treatment a normalization of the altered pattern was observed. Within the CF-groups a strong correlation between the release of LTB4, its metabolites, the histamine release per basophil, the total histamine content and clinical (e.g. pO2 FEV1) and laboratory findings (e.g. IgE and IgG levels, CRP) was established. Our data suggest that the inflammatory process in patients with CF is associated with an alteration of the lipoxygenase pathway and histamine releasability of granulocyte subpopulations which correlates with the clinical signs of inflammation.

Generation and metabolism of leukotrienes in granulocytes of patients with cystic fibrosis.

We studied the generation and metabolism of lipoxygenase products in peripheral granulocytes from children suffering from cystic fibrosis (CF). Peripheral granulocytes were stimulated at different times (days) before and during anti-infectious treatment with the Ca ionophore (7.5 microM, 5 and 20 min), opsonized zymosan (2 mg) and arachidonic acid (50 microM); the amount of lipoxygenase products in the cell supernatants was determined by high performance liquid chromatography. Granulocytes from patients with CF, compared to an age-matched control group, showed an increased omega-oxidation of the synthesized leukotriene (LTB4) into 20-OH- and 20-COOH-LTB4 after stimulation with the Ca ionophore (ratio of LTB4 versus omega-oxidated products in patients with CF: 0.77 +/- 0.07, mean +/- SEM, n = 11; control group: 1.07 +/- 0.1, n = 11, p less than 0.01) whereas the combined amounts of LTB4 and its omega-oxidated products did not differ significantly. A comparable profile was observed with opsonized zymosan. Stimulation of the cells with the Ca ionophore combined with arachidonic acid led to a significantly increased formation of lipoxygenase products in the patient group, whereas only a slight enhancement was observed in the control group. During the 14-day anti-infectious treatment a normalization of the altered pattern was observed. 12-Hydroxyeicosatetraenoic acid (12-HETE) production from platelets within the granulocyte fraction was significantly depressed in the CF group compared to the controls (38.5 +/- 12.5 versus 339 +/- 93 ng/5 +/- 10(6) cells, p less than 0.005). Within the CF group a strong correlation between the release of LTB4 and its metabolites, the production of 12-HETE and clinical (e.g. pO2, FEV1) and laboratory findings (e.g. IgE and IgG levels, C-reactive protein) was established. Our data suggest that the inflammatory process in patients with CF is associated with an alteration of the lipoxygenase pathway of granulocytes which correlates with the clinical signs of inflammation.

Histamine release from basophils in cystic fibrosis.

We determined the histamine release from basophils in patients suffering from cystic fibrosis (CF) (median 17.2 years of age) and compared the data with an age-matched group of healthy donors. No significant differences in the basophil counts were determined between the CF and control groups. However, the absolute histamine content per basophil was elevated in the CF group (2.6 +/- 0.4 pg/basophil versus 1.4 +/- 0.2, mean +/- s.e.m., n = 15/10, P less than 0.004). Stimulation of basophils with the Ca ionophore (7.5 microM) and anti-IgE (10(-2) of a stock preparation) leads to a significantly higher release of histamine per basophil in CF patients as compared to healthy donors (Ca ionophore: 1.6 +/- 0.2 versus 0.9 +/- 0.2, mean +/- s.e.m., P less than 0.008; anti-IgE: 0.45 +/- 0.007 versus 0.28 +/- 0.04, P less than 0.02). These data indicate that basophils in CF may have a greater potential to release mediators although their releasability, expressed as the percentage of histamine release of the total histamine content, does not differ significantly compared to the healthy donors (62.1 +/- 8.3% versus 60.2 +/- 13%, mean +/- s.e.m.). Within the 14-day period of intravenous antibiotic treatment of the pulmonary infection (in 14 out of 15 cases P. aeruginosa was isolated from sputa samples) histamine release per basophil and total histamine content decreased to normal levels (day 1 2.6 +/- 0.3 versus 1.8 +/- 0.3, P less than 0.05). This decline was accompanied by an improvement of the clinical condition of the patient and reduction of P. aeruginosa isolates in sputa (n = 8). In contrast, in three patients with sustained P. aeruginosa colonization of the upper airways and impaired lung function histamine levels remained elevated. Our data demonstrate that the histamine content of basophils, as well as the release of histamine, is increased in patients with cystic fibrosis and correlates with the clinical signs of the chronic infection.