Nasal carriage of superantigen producing Staphylococcus aureus and its role in pathogenesis of allergic rhinitis and bronchial asthma

Staphylococcal enterotoxins can act as allergens and stimulate production of specific IgE with subsequent development of allergic manifestations. In addition, they act as superantigens that induce cytokine secretion with more increase of IL-4/IFN-gamma ratio causing augmentation of allergic reactions. Herein we tested the hypothesis that exposure to Staphylococccus aureus and its enterotoxins induces immunological changes that contribute to the pathogenesis of allergic rhinitis and bronchial asthma. This study included 45 air way allergic patients, and 45 controls. The following were done: intradermal allergy skin testing, invitro effect of staphylococcal enterotoxin B [SEB] on cytokine secretion from separated peripheral blood mononuclear cells, detection of nasal carriage of S. aureus and its enterotoxin production by ELISA and serum levels of total IgE, SEB-specific IgE and eosinophil cationic protein [ECP] were measured. We found that nasal carriage of enterotoxin producing S. aureus in allergic patients was significantly higher than in control. Blood eosinophilia, total IgEand ECP levels were significantly higher in S. aureus nasal carrier than non-carrier patients. On in vitro exposure of PBMCs to [SEB], IFN-gamma secretion was significantly less in patients than control and IL-4 secretion was significantly more in patients than control. SEB-specific IgE was detected in 15.6% of patients and not detected in control. There was a significant positive correlation between SEB-specific IgE level in patients and markers of severity of allergic reaction including blood eosinophilia, ECP and total IgE level. This study suggests that nasal carriage of enterotoxin producing S. aureus has a potential role in the development and severity of allergic airway diseases

Diarrhea in neutropenic children with cancer: an Egyptian center experience, with emphasis on neutropenic enterocolitis

Diarrhea is a frequent complication in patients with cancer. It may be caused by several factors including conventional gastrointestinal pathogens, suppression of normal intestinal flora as well as noninfectious causes such as mucositis and bowel ischemia, with neutropenic enterocolitis [NE] being the most serious. To study diarrhea in neutropenic cancer patients in the pediatric age group, with its underlying etiologies and risk factors especially the bacterial causes with special concern on NE. The study was carried out at the Pediatric Hematology and Oncology Units, Zagazig University Hospitals, Egypt, from Januray 2009 to September 2010. Neutropenic cancer patients who developed diarrhea were grouped into 2 groups: group [1], with NE, and group [2], with neutropenic diarrhea rather than NE, On the first day of diarrhea, patients were subjected to: complete blood count, blood cultures [if febrile], stool microscopy [for red and white blood cells, ova and parasites], and stool culture [for specific pathogens]. Abdominal ultrasonography was carriad out within 3 days of the onset of diarrhea. A total of 200 children