To confirm local production of IgE, and evaluate role of immunoglobulins on eosinophil activation in nasal polyp (NP) tissue, we measured IgG, IgA, secretory IgA(sIgA), total (tIgE) and specific IgE (sIgE) to Dermatophagoides pteronyssinus(DP) by ELISA in NP tissue homogenates from 51 subjects. They were classified according to skin reactivity to DP: group I, 15 highly atopic subjects; group II, 18 weakly atopic subjects; and group III, 18 non-atopic subjects. Eosinophil cationic protein (ECP) level was measured by CAP system. Highest level of DP-sIgE was noted in group I, followed by group II and III (p<0.05). Nine (60%) of group I and 4 (22%) of group II subjects had detectable level of DP-sIgE with no significant differences in IgA, sIgA, and IgG. All of NP tissue had eosinophilic infiltration with no significant difference in activated eosinophil count or ECP level among 3 groups. A significant correlation was noted between EG2+ cell count and tIgE (r=0.55, p<0.05), and DP-sIgE level (r=0.60, p<0.05). A significant correlation was also noted between ECP and IgG (r=0.51, p<0.05) and DP-sIgE level (r=0.47, p<0.05) with no significant correlation with IgA or sIgA. These results suggest that DP-sIgE was detectable in NP tissue from weakly atopic subjects as well as highly atopic subjects. IgG and sIgE may have potential roles in eosinophil degranulation in NP tissue.
Blood Proteins/analysis ; Cell Degranulation/immunology ; Dermatophagoides pteronyssinus/immunology ; Eosinophil Granule Proteins ; Eosinophils/immunology ; Humans ; Immunoglobulin A/analysis/immunology ; Immunoglobulin E/analysis/immunology ; Immunoglobulin G/analysis/immunology ; Immunoglobulins/analysis/*immunology ; Nasal Polyps/*immunology/pathology ; *Ribonucleases

It has been suggested that dendritic cells (DCs) are critical antigen presenting cells for eosinophilic airway inflammation in a mouse model of asthma, and cysteinyl leukotrienes may play a role in DC trafficking in asthmatics. We investigated whether the number of DCs is increased in the induced sputum of both atopic and nonatopic asthmatics and is related to activated eosinophil count in the sputum. Sputum was induced by inhalation of hypertonic saline in 9 atopic and 12 nonatopic asthmatics and 10 nonatopic normal controls, and differential cell counts were performed. DCs and activated eosinophils were identified by immunocytochemistry with monoclonal antibodies (anti-CD1a and EG2, respectively). There were significantly higher percentages of eosinophils, EG2+ cells, and CD1a+ DC in the sputum of atopic and nonatopic asthmatics compared with normal controls, respectively. In asthmatics, the percentage of CD1a+ DC was significantly correlated with that of EG2+ cells (Rs=0.62, p=0.004). We demonstrated that the increased number of DCs was evident in the induced sputum of both atopic and nonatopic asthmatics, and the DC number was related to the activated eosinophil count, which suggests that DCs may contribute to the ongoing eosinophilic inflammation in asthmatic airways, and vice versa.
Adult ; Aged ; Antigens, CD1/analysis ; Asthma/*immunology/pathology ; Comparative Study ; Dendritic Cells/*immunology ; Eosinophil Granule Proteins/analysis ; Eosinophils/cytology/*immunology ; Female ; Humans ; Immunohistochemistry ; Leukocyte Count ; Male ; Middle Aged ; Research Support, Non-U.S. Gov't ; Sputum/cytology/*immunology