Annelie Möller

Inhibition of cytokine secretion from human leukemic mast cells and basophils by H1- and H2-receptor antagonists

Abstract: H1‐type antihistamines have recently been reported to inhibit cytokine secretion from human and murine mast cells and basophils. In order to confirm and expand these studies, we have compared several H1‐blockers and the H2‐blocker ranitidine for their effect on TNF‐α, IL‐3, 6, 8 and GM‐CSF release from human leukemic mast (HMC‐1) and basophilic (KU812) cells, compared to dexamethasone. Cells were stimulated for 24 h with phorbol myristate acetate (25 ng/ml) and calcium ionophore A 23187 (2.5×10−7 M) alone or with the drugs added at 10−4 to 10−15 M, and production of cytokines was measured by ELISA. All antihistamines caused a dose‐dependent inhibition of TNF‐α release from HMC‐1 cells, with maximal effects at 10−12 M for azelastine, 10−9 M for loratadine and cetirizine, and 10−8 M for ranitidine. The inhibitory potency of H1‐blockers on cytokines from HMC‐1 cells was TNF‐α >IL‐8≥IL‐6≥IL‐3, with no significant effects on GM‐CSF. In KU812 cells which failed to secrete TNF‐α and GM‐CSF, the sequence was IL‐6 >IL‐8 after preincubation. Dexamethasone inhibited all cytokines, but ranitidine only TNF‐α and IL‐3. Antihistamines had no effect on calcium flux in resting or stimulated cells. At the mRNA level, inhibition was only seen with KU812 cells and IL‐8 in the presence of azelastine at 10−10 M. These data show thus distinct inhibitory patterns for different antihistamines during cytokine production from human mast cells and basophils which may contribute to the anti‐inflammatory effects of these drugs during treatment of allergic diseases.

Pharmacological modulation of IL‐6 and IL‐8 secretion by the H1‐antagonist decarboethoxy‐loratadine and dexamethasone by human mast and basophilic cell lines

Abstract Mast cells and basophils are central effector cells of allergic reactions and are involved in inflammatory diseases. These cell types produce an array of mediators including a broad spectrum of cytokines. In order to examine whether antiallergic drugs modulate the release of these mediators, we have investigated the influence of dexamethasone and decarboethoxy‐loratadine (DEL), the active metabolite of the H1‐blocking agent loratadine, on the release of IL‐6 and IL‐8 by the human mast cell line HMC‐1 and the human basophilic cell line KU812 by ELISA. Dexamethasone (10−6‐10−11 M) or Del (10−5‐10−14 M) were added to the cells either 1 h prior to or simultaneously with PMA and Ca‐ionophore A23187. When preincubated with the cells, DEL dose‐dependently suppressed IL‐6 release by up to 40% and IL‐8 release by up to 50%. Dexamethasone potently suppressed secretion of both cytokines if simultaneously added to the cells with the stimuli by up to 60% and after preincubalion by up to 80%. Since both antihistamines and glucocorticoids are used for treatment of allergic diseases, the findings reported here indicate that these drugs may modulate allergic reactions via inhibition of cytokine release from mast cells and basophils.

Epidemiologie und Klinik der Kälteurtikaria

ZusammenfassungUm einen Einblick in Häufigkeit und Klinik der Kälteurtikaria in Mitteleuropa zu erhalten, wurde eine Analyse der in den Jahren 1984–94 betreuten Patienten einer Universitätspoliklinik bzw. einer Hautarztpraxis anhand von Patientenakten und teilweise auch durch Nachuntersuchungen vorgenommen. Die Inzidenz der Kälteurtikaria betrug danach 0,05%. Von insgesamt 56 betroffenen Patienten (31 Frauen, 25 Männer) litten 49 an der idiopathischen Form der Erkrankung. Das mittlere Lebensalter betrug 41,0±15,6 Jahre, die mittlere Krankheitsdauer 7,9±5,8 Jahre. Bei 46,4% der Patienten bestand eine Atopie, 23,2% litten an anderen Urtikariaformen (cholingerische, chronische idiopathische, dermographische, aquagene und Wämeinduzierte Urtikaria). Laboruntersuchungen waren nur in Einzelfällen positiv. 44 Patienten wurden mit Antihistaminika behandelt, mit meist nur mäßiger symptomatischer Besserung. Während einer Behandlung mit Antibiotika (Penicillin 1–2 Mio IE/d über 2–4 Wochen, n=18 bzw. Tetrazykline 2 g/d über 2 Wochen, n=10) erfolgte bei 13 Patienten eine Vollremission und es wurde bei 8 eine Besserung erzielt. Bei 20 der symptomatischen Patienten (46,5%) erfolgte über eine 6,5jährige Nachbeobachtungszeit eine Spontanremission. Die überraschend guten Behandlungserfolge mittels Antibiotikatherapie unterstreichen die Notwendigkeit einer weiteren Aufklärung der Pathogenese dieser Erkrankung, auch im Hinblick auf eine mögliche infektiöse Ursache.SummaryTo study the frequency and clinical aspects of cold urticaria in Central Europe, patient data from a university dermatology clinic and a private dermatology office between 1984–94 were analysed and the patients reexamined if possible. The incidence of cold urticaria was found to be 0.05%. Of the 56 patients with cold urticaria (31 women, 25 men), 49 had idiopathic cold urticaria. The mean age was 41.0±15.6 year, the mean duration of disease 7.9±5.8 years. Atopy was found in 46.5% of patients, and 23.2% of the patients suffered from other types of urticaria (cholinergic, chronic idiopathic, dermographic, aquagenic and heat-induced). Laboratory examinations were only rarely abnormal. 44 patients were treated with antihistamines, with generally only moderate symptomatic improvement. Treatment with antibiotics (penicillin, 1–2 mil IU/d over 2–4 weeks, n=18, or tetracyclines, 2 g/d over 2 weeks, n=10) induced full remission in 13 patients and symptomatic improvement in 8. During an average of 6.5 year-follow-up, 20 of 43 symptomatic patients went into spontaneous remission. The good therapeutic response to antibiotics in this study underlines the need for a better elucidation of the cause of cold urticaria, in view of possible infectious causes.

Role of Antigen-Induced Cytokine Release in Atopic Pruritus

In order to further evaluate the role of cytokines in the induction of atopic pruritus, leukocytes from 10 atopic eczema patients or 10 nonallergic controls were stimulated in vitro with mite or birch pollen antigen for 1 and 4 days. Subjects were prick-tested with the supernatants, and whealing and itching were evaluated 20 and 60 min later. The supernatants were also examined for the contents of GM-CSF, IL-2, IL-6 and IL-8 by ELISA and TNFα. Two hours prior to testing, the antihistamine cetirizine (20 mg) or a placebo tablet were given to the patients according to a randomized, double-blind study protocol. After pricking with antigen-stimulated leukocyte supernatants, 6 of 10 patients but no controls reacted mostly at 20 min with whealing and/or pruritus. In the cetirizine-treated group, no decrease in these skin reactions was seen compared to placebo. Analysis for cytokines showed increased levels of IL-8 in allergen-stimulated samples, with no correlation to the induction of itching or whealing by these supernatants. IL-6 levels were low and variable, and GM-CSF, IL-2 and TNFα levels were always below standard values. These data show that leukocytes selectively release IL-8 in response to in vitro antigen stimulation. They furthermore provide additional support for the concept that as yet to be identified products play a role in atopic pruritus.

Glucocorticoid-induced modulation of cytokine secretion from normal and leukemic human myelomonocytic cells.

Since glucocorticoid effects on inflammatory processes may be mediated via modulation of cytokine release, different types of myelomonocytic cells were stimulated in vitro with lipopolysaccharide (50 ng/ml) or phorbol myristate acetate (25 ng/ml) plus the ionophore A23187, 2 x 10(-7) M, and release of interleukin (IL)-1 beta, IL-8 and tumor necrosis factor (TNF)-alpha was measured after 24 h by ELISA. Peripheral blood mononuclear cells from two allergic and two normal human donors released similarly large quantities of IL-8 and lower amounts of IL-1 beta and TNF-alpha. This also held for myelomonocytic cell lines, with THP-1 cells being most active, followed by U-937 and HL-60 cells. All potent glucocorticoids studied caused a dose-dependent inhibition of cytokine release from donor cells, being most marked for IL-1 beta and lowest for IL-8. Inhibition of cytokine release was also noted with U-937 cells, with clear differences in potency between the glucocorticoids, whereas release was enhanced in all experiments with THP-1 cells. These results were confirmed with Northern blot analysis. Modulating effects of glucocorticoids on cytokine release are thus complex, and are particularly dependent on the cell type studied.

Modulation of in vitro Cytokine Release from Human Leukemic Mast Cells (HMC-1) by Glucocorticoids

Mast cells are well known effector cells not only in allergic but also in diverse acute and chronic inflammatory diseases. We have shown previously that these cells produce a broad spectrum of cytokines which might contribute to mast cell-dependent pathology. In the present study, we have investigated the influence of four potent glucocorticoids, methylprednisolone-aceponate, methylprednisolone-17-propionate, prednicarbate, and betametasone valerate (10(-5) M-10(-9) M), on the IL-1 beta, IL-3, IL-8, and tumor necrosis factor alpha secretion of the HMC-1 mast cell line as measured by ELISA. All four glucocorticoids caused a comparable dose- and time-dependent inhibition of cytokine release from HMC-1 cells stimulated for 24 h with phorbol 12-myristate 13-acetate 25 ng/ml and calcium ionophore 2 x 10(-7) M. These results shed further light on the mechanisms involved in antiinflammatory effects of glucocorticoids in allergic inflammation.