S. Van Der Baan

Eosinophils in nasal polyps and nasal mucosa: An immunohistochemical study

Immunohistochemical staining was performed at the time of endoscopic sinus surgery (ESS), after 6 months, and after 1 year on nasal polyps and biopsy specimens of the macroscopically unaffected mucosa of the middle and inferior turbinate bones of 46 patients with nasal polyps. During the follow-up period the patients were treated with topical corticosteroids. At time of ESS significantly more BMK13+ and EG1+ (pan eosinophil markers) and EG2+ (activation marker) eosinophils were found in the polyps than in the macroscopically unaffected mucosa of the middle and inferior turbinate bones of the patients. In the middle and inferior turbinate bones of 10 healthy subjects no EG2+ (activated) eosinophils were detected, whereas low-to-moderate numbers of BMK13+ and EG1+ eosinophils were seen in these specimens. This emphasizes that eosinophils play a role in the pathogenesis of nasal polyps. Compared with numbers at ESS, after 6 months and 1 year of follow-up, lower numbers of BMK13+, EG1+, and especially of EG2+ eosinophils were found in recurrences of polyps and in the macroscopically unaffected mucosa of the middle and inferior turbinate bones of the patients. The decrease in number of EG2+ (activated) eosinophils is an indication of a reduced local inflammatory reaction, and could be an important factor in postponement of recurrences of nasal polyps.

Clinical aspects and distribution of immunologically active cells in the nasal mucosa of patients with nasal polyps after endoscopic sinus surgery and treatment with topical corticosteroids

SummaryClinical parameters of 72 patients who were operated upon for nasal polyps were evaluated as well as biopsy specimens of the mucosa of the middle and inferior turbinates of 41 of these patients. Biopsies were taken at the time of endoscopic sinus surgery (ESS), after 6 months and after 1 year in 23 patients. During the follow-up period the patients were treated with topical corticosteroids (budesonide). At the time of ESS significantly more CD8+ (suppressor/cytotoxic) cells than CD4+ (helper/inducer) cells were found in the middle and inferior turbinates. At 6 months significantly more CD4+ cells were found than at the time of ESS, whereas at 1 year the number of CD4+ cells had decreased and was lower than at 6 months. These data support the theory that the occurrence of nasal polyps is associated with T-cell-dependent disturbances. Clinical evaluation revealed that most of the patients with chronic airway obstruction had better pulmonary functions postoperatively or required less medication for lung disease. These findings show that ESS combined with topical corticosteroids has a positive effect on upper and lower respiratory tract pathology.

Lymphoid and non-lymphoid cells in the adenoid of children with otitis media with effusion : a comparative study

We characterized on immuno‐ and enzymecytochemical level the lymphoid and non‐lymphoid cells in the adenoid of children with upper respiratory tract infections (URI) and otitis media with effusion (OME) and compared these with the adenoid of children with URI without OME and with the adenoid of ‘healthy’ children and adults. Besides macrophages and dendritic cells we also showed the presence of MHC class II positive, ciliated, epithelial cells. These non‐lymphoid cells were present in all adenoids. However, their number was less than 1% of all cells. We found no difference in lymphocyte subsets from children with URI+OME compared with those from children with URI alone. These two groups showed a significant decrease of CD8‐positive (suppressor/cytotoxic) cells and a slight increase in CD22‐positive B cells in comparison to ‘healthy’ children. No difference was found in percentages of CD4‐positive (helper/inducer) cells. The localization of the lymphoid subsets in adenoids of children with URI and/or OME did not differ from those of ‘healthy’ children and adults.

Distribution of retroviral p15E-related proteins in neoplastic and non-neoplastic human tissues, and their role in the regulation of the immune response

In patients with head and neck carcinomas and in patients with chronic purulent upper airway infections, low molecular weight retroviral p15E‐like factors are found. These factors are responsible for partial defects in the cellular immune response. We studied the distribution of these p15E‐related proteins in neoplastic. inflamed and normal human tissues and related these findings with the presence of p15E‐like factors in patientss era. Demonstration of p15E‐like proteins in sera of patients with upper airway infections and of patients with head and neck carcinomas correlated exclusively with the presence of p15E in normal and pathologic epithelium of the upper respiratory tract, p15E was not demonstrated in epithelia of other localizations. Our results suggest that chronic stimulation or neoplastic transformation of the epithelia of the upper respiratory tract stimulates the production of p15E‐like proteins leading to their reported immunosuppressive actions.

Isolation and characterization of dendritic cells from adenoids of children with otitis media with effusion

Dendritic cells were enriched from adenoids of children with otitis media with effusion (OME) by density gradient centrifugation and culture techniques. An enrichment of 40–140‐fold was obtained for dendritic cells. These cells were identified using morphology, enzyme cytochemistry, immunocytochemistry and functional criteria. Dendritic cells could be easily distinguished from macrophages. It appeared that the MoAb EBM 11 (CD68) discriminated between dendritic cells and macrophages; in dendritic cells this activity was localized in a spot, whereas in macrophages it was found throughout the whole cytoplasm. The fractions enriched with dendritic cells showed a strong stimulatory effect on allogeneic T cells. These responses were MHC class II dependent since they could be blocked by anti‐HLA‐DR/DQ MoAbs. The data clearly show that dendritic cells from adenoids of children with OME still have functional capacities.