A novel IL-1 family cytokine, IL-33, potently activates human eosinophils.

BACKGROUND: Eosinophils are likely key cells involved in the pathogenesis of asthma and allergic diseases; however, the mechanisms that regulate eosinophil dynamics and functions in mucosal tissues are incompletely understood. IL-33, which is produced by mucosal cells, is a new member of the IL-1 cytokine family. Mice injected with IL-33 display profound mucosal eosinophilia with associated pathologic changes. Although mast cells and T(H)2 cells express the IL-33 receptor, ST2, the roles of IL-33 and ST2 in eosinophil biology are unknown. OBJECTIVES: We investigated the effects of IL-33 on human eosinophils in vitro. METHODS: Eosinophils and neutrophils were isolated from blood of normal individuals and mildly atopic patients. Real-time RT-PCR and flow cytometry were used to detect ST2. Granulocyte responses to IL-33 were monitored by superoxide anion production and by degranulation; IL-5, IL-1beta, and TNF-alpha served as controls. Eosinophil survival and cytokine production were assessed by flow cytometry and ELISA, respectively. RESULTS: ST2 mRNA and protein were detected on eosinophils. IL-33 induced eosinophil superoxide anion production and degranulation as potently as IL-5. IL-33 also increased eosinophil survival and induced production of IL-8. Anti-ST2 inhibited eosinophil responses to IL-33. Neutrophils did not express ST2, nor did they respond to IL-33. CONCLUSION: IL-33 and its receptor, ST2, may play important roles in eosinophil-mediated inflammation; they may provide new therapeutic targets for controlling mucosal eosinophilic inflammation.

Chronic rhinosinusitis in adults.

There is no consensus on diagnostic criteria for chronic rhinosinusitis. By convention, the symptoms of chronic rhinosinusitis are similar to those of acute rhinosinusitis but last more than 8 weeks. Diagnosis is based on history, physical examination, and computed tomography scan of the sinuses or rhinoscopy. Treatment options are numerous and, for the most part, not evidence based. They include antibiotics, nasal or oral corticosteroids, antihistamines, naval lavage, decongestants, immunotherapy, and surgery. Which diagnostic and therapeutic options to exercise when, is the focus of this article.

Rectus sheath hematoma: review of 126 cases at a single institution.

Rectus sheath hematoma (RSH) is an uncommon condition characterized by abdominal pain and an abdominal wall mass. We reviewed the clinical features, treatment, and outcomes of 126 patients treated for RSH at Mayo Clinic from January 1, 1992, to December 31, 2002. Most patients (64%) were women and the mean +/- SD age was 67.9 +/- 16.5 years. Most patients (69%) were on some form of anticoagulation therapy. The mean international normalized ratio was 2.6 +/- 2.4, and mean activated partial thromboplastin time was 64.2 +/- 42.7 seconds. No patients were pregnant or had a peritoneal dialysis catheter at the time of diagnosis. Approximately half of the patients (48%) had nonsurgical abdominal trauma around the time of diagnosis, with 37 patients (29%) having a cough. The most common presenting signs and symptoms were abdominal pain (84%) and an abdominal wall mass (63%). CT of the abdomen and pelvis was the most commonly used method to establish the diagnosis (83%). Most patients (86%) were successfully treated with symptom management and blood transfusion. Ten patients (7.9%) underwent surgery or endovascular embolization of bleeding vessels, and 2 patients (1.6%) died as a result of RSH bleeding. Although RSH is rarely fatal, the clinician should be aware of important risk factors that lead to RSH including female sex, older age, anticoagulation therapy, and cough or other abdominal trauma. Rapid diagnosis with directed history, physical examination, and CT of the abdomen and pelvis may help decrease unnecessary laparotomy and lead to better triage of patients who present with RSH.