Artykuły w Czytelni Medycznej o SARS-CoV-2/Covid-19

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© Borgis - New Medicine 1/2001, s. 58-61
Elzbieta Maciorkowska1, Beata Szynaka2, Maciej Kaczmarski1, Andrzej Kemona2
Helicobacter pylori and chronic urticaria in children
1 IIIrd Department of Paediatrics, Medical Academy of Bialystok, Poland
Head: Professor Maciej Kaczmarski MD, PhD
2 Institute of Pathological Anatomy, Medical Academy of Bialystok, Poland
Head: Professor Boguslaw Musiatowicz MD, PhD
The authors carried out an ultrastructural evaluation of the gastric and duodenal mucosa in H. pylori-infected children with co-existing urticaria. In all cases, inflammatory cells such eosinophils and neutrophils, plasmocytes, lymphocytes and mast cells were found in the mucosal membrane under the epithelium, in the vicinity of vessels. The surface of mast cells subjected to degranulation had significantly fewer processes than the surface of undamaged cells. Granulocytes and plasmocytes were noticed in the vicinity of mast cells subjected to degranulation. There was a segmental loss in the endothelial lining and only the basement membrane determined the vessel continuity.
The majority of studies indicate the significant role of H. pylori in the pathogenesis of chronic active gastritis and duodenitis (10, 11). The administration of H. pylori to volunteers causedhistologically-defined gastritis (4). Its eradication led to a regression of symptoms, while re-infection resulted in frequent recurrence of clinical ailments (5, 9). Although the precise mechanism through which H. pylori infection affects mucosa is not clear, this bacterium is considered to produce and release substances activating and attracting neutrophils which then cause tissue damage (4, 11, 23). The observation supporting this hypothesis proves that the severity of H. pylori infection depends on the size of a neutrophilic infiltration and the extent of mucosal damage (2).
Mai and Craig report that H. pylori extracts contain substances causing chemotactic activity in neutrophils and monocytes (7,16) and its water extracts enable leukocyte adhesion and their migration from the mesenteric veins (24). These phenomena suggest that H. pylori infection may lead to gastrointestinal mucosa damage through the initiation of an acute inflammatory reaction. Gastrointestinal inflammation is accompanied by changes in the structure and function of vessels, manifested in the increased microvascularpermeability of fluid and proteins (14).
Kurose et al. showed that microvascular malfunction in the inflamedmucosa is not only associated with leucocyte adhesion and migration butother myelocytessuch as mast cells and platelets, as well. They cause an increase in the permeability (14).
Kurose was the first to find out that H. pylori extracts may induce perivascular mast cell degranulation (14). This degranulation was already advanced10 minutes after the exposureof the mesenteric cells to H. pylori hydric extract.
The authors evaluated the significant influence of Ketotifen, which limitedthe degranulation of H. pylori hydric extract-induced mast cells and prevented early vascular albumin exudate.
Activated mast cells release pro-inflammatoryagents that can enhance microvascular permeability. They include platelet activating factor (PAF), leukotrienes (B4), histamine and tryptase. However, Bechi et al.prove that H. pylori extracts have no influence on the isolated mast cell, indicating that themechanism of mast cell degranulation in vivo is still unknown and needs further investigation (3).
Pink or porcelain urticarial wheals appearing rapidly and resolving within severalhours without any sign, result from the release of various mediators by degranulating mast cells in H. pylori - inflamed gastric mucosa. Urticarial changes are accompanied by itching.
An urticarial wheal is produceddue to the enhanced permeability of vessels and swelling caused by the release of histamine and other mediators including neuropeptides.
The purpose of our study was the ultrastructural evaluation of the gastric and duodenal mucosa in H. pylori - infected children with chronic urticaria.
The studies were performed in 7 children aged 11-18 years (mean age 14.4 years) with chronic urticaria and dyspeptic symptoms of the gastrointestinal tract. There were 4 girls and 3 boys, and 2 children constituted controls. Children were hospitalised in the IIIrd Department of Paediatrics or treated in the Outpatient Gastrology Department. Endoscopic examinations of the upper gastrointestinal tractwere performed in all patients with chronic symptoms. During endoscopy the urease test (CLO-test) was made and mucuswas taken from the duodenum to exclude Giardia lamblia infection.
To evaluate gastric mucosa morphologically in each patient, 2 sampleswere obtainedfrom the pyloric segment at a distance of 2-3 cm from the pylorus, and from the corpus about 8 cm from the antrum. Two samples of mucosa were taken from the extra bulbar part of the duodenum. The samples were placed in 10% neutralized formalin.
Additionally, biopsy specimens were taken from antrum, corpus and duodenum for ultrastructural examination. They were fixed in 3.6% glutaraldehyde at 4o C for 2 hrs and postfixed in 2% osmium tetroxide for 1hrs. After dehydration in alcohol, they were washed in propylene oxide and embedded in Epon 812. The ultrathin sections were cut on a Reichert ultramicrotome, doubly stained with uranyl acetate and lead citrate, and examined using an electron microscope EM 900 PC (OPTON West Germany).
All examinations were carried out with the consent of the children´s parents and approved by the Committee of Ethics and Supervision over Human and Animal Examinations, Medical Academy of Bialystok.
Results and discussion
Many reports describe relationships between H. pylori infection and other diseases which are not related to the gastrointestinal tract, particularly H. pylori infection and vascular diseases (1,18). Some authors suggest a correlation between H. pylori infection and the occurence of urticaria and acne erythematosa (18).
All substances produced in H. pylori infection may play a role in the pathogenesis of diseases not associated with the gastrointestinal tract (1,18).
Helicobacter pylori infection may have a direct or indirect effect by triggering immune andinflammatory responses (1). Cytokines and other cell mediators of an acute stage can be especially connected with vasomotor disorders.
In 1972, when H. pylori and its association with gastric mucosa inflammation were unknown,von Gloor showed gastric dysfunction in patients with chronic urticaria (25).
Juhlin et al. in 1981 described dyspeptic symptoms in 44% of patients with recurrent chronic urticaria (12).
In 1994 Kolibasova et al (13) associated the regression of dyspeptic symptoms with H. pylori eradication, and Tebbe (1996) notedcomplete regression of urticaria in 47% and partial in 35% of patients after eradication therapy (21).
Liutu was the next author to relate H. pylori infected gastric mucosa inflammation to urticaria (1998); 43 of a total of 53 patients with urticaria had H. pylori infection. After successful H. pylori eradication in 32 patients urticaria symptoms did not reappear in 78%during the 6 months´follow-up (15).

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New Medicine 1/2001
Strona internetowa czasopisma New Medicine