Determination of a CD4+CD25+ Foxp3+T cells subset in Egyptian Colorectal Cancer Patients.

Human tumors including colorectal cancers (CRC) are often infiltrated by immune cells predominantly T lymphocytes especially regulatory T (Treg) cells expressing the forkhead box protein 3 (Foxp3). It has been suggested that CD25+CD4+Foxp3+ regulatory T cells (Tregs) might hamper effective immunosurveillance of emerging cancer cell. The aim of this study was to measure the frequency of total CD4+CD25+ Tregs & CD4+CD25+Foxp3+ subset of Treg cells in peripheral blood of Egyptian CRC patients and their correlation with the tumor stage, histopathology of the tumor and lymph node affection. A total of 31 CRC patients were enrolled in the study. The tumor was categorized using a TNM staging system. Peripheral blood samples were collected within the first 24 h of surgery. The frequency of total CD4+CD25+ Tregs & CD4+CD25+ Foxp3+ subset of Treg cells in peripheral blood mononuclear cells (PBMCs) were measured by flow cytometry and absolute count was determined. High frequency of Tregs was detected in cancer patients with distal margin involvement (44-48 cells/µL) compared with those with free distal margin (5-32 cells/µL). Similarly, higher frequency of Tregs were detected (16-44 cells/µL) in cancers with lymph node involvement compared with cancers without lymph node involvement (5-32 cells/µL). Higher frequency of CD4+CD25+Foxp3+ Tregs were found in mucinous adenocarcinomas than in other histopathological types, although both observations were statistically insignificant. The median value for total absolute lymphocyte count/ µL was 639, out of which CD4+CD25+ subset constituted 35 cells, and about half of this subset were Foxp3+Tregs. In conclusion, CD4+CD25+Foxp3+ Tregs may be a useful marker for predicting invasion, metastasis, and prognosis of colorectal cancer in Egyptian patients.

Role of IL-13 in the pathogenesis of bronchial asthma.

Asthma is a chronic inflammatory disease of the lung. Although it is multifactorial in origin, the inflammatory process is believed to be a result of inappropriate immune responses to common aeroallergens in genetically susceptible individuals. As such, it has been reported that Th2 cytokines play a pivotal role in the pathogenesis of disease. The aim of this study was to evaluate the role of IL-13 in the pathogenesis of bronchial asthma. The study was carried out on 71 subjects out of which 54 were asthmatic patients and 17 were normal controls. Patients with bronchial asthma were further classified according to the National Asthma Education and Prevention Program (NAEPP) into 4 groups: intermittent, mild persistent, moderate persistent and severe persistent. IL-13 serum levels were estimated in patients and controls by ELISA. Asthmatic patients showed a statistical significant elevation of serum IL-13 levels (mean = 78.5 +/- 64.5 pg/ml) as compared to controls (mean = 51.8 +/- 24.9 pg/ml). When patients with different degrees of severity were compared, a significant increase in serum IL-13 was found in patients with intermittent asthma (mean = 106 +/- 105 pg/ml) as compared to those with mild (mean = 63.6 +/- 14.7 pg/ml) and severe persistent asthma (mean = 64.9 +/- 29.1 pg/ml). Only patients with intermittent asthma showed a highly significant increase in serum IL-13 than controls. No statistically significant difference was found between patients not on steroids, patients on inhaled steroids and those on systemic steroids. A statistically significant increase in IL-13 serum levels was observed in patients not on steroids compared to normal controls. A significant increase in blood eosinophil counts was found in patients during acute asthmatic attacks as compared to those who were stable. In conclusion, IL-13 is a key cytokine with critical role in the immunopathogenesis of bronchial asthma. Steroids can downregulate IL-13, but inhaled steroids alone might not be able to abolish the airway remodeling process in asthmatics. Although patients with intermittent asthma are asymptomatic in between exacerbations, inflammation and remodeling are ongoing in their lungs.