Immunologic response of adenoidal lymphocytes to respiratory syncytial virus

Low-dose multicomponent medication modulates humoral and cellular immune response in an ex-vivo study on children subjected to adenoid surgery

Respiratory infections, mainly in children, are a demanding challenge for physicians. Commonly, a relative immune-defect sustains their recurrence. At present, there is no standardized treatment for their prevention acting on the immune system. Citomix is a low-dose multicomponent medication largely used in this issue. The current study evaluated its ex vivo effect on adenoidal mononuclear cells recovered from children operated for adenoid hypertrophy. B cell phenotype, and IFN-γ, IL-6, IL-10, IgG, IgA, IgM in culture supernatants were evaluated. Citomix was able to significantly increase the expression of B memory cells, IFN-γ, IL-6, IgA and IgM, and significantly decrease IL-10 and IgG. The current outcomes could be consistent with a strategy deputed to improve the early immune response to pathogens. In conclusion, the present ex vivo study suggests that Citomix might be a promising medication in preventing and early treating respiratory infections.

Impact of passive smoke and/or atopy on adenoid immunoglobulin production in children

The adenoids are exposed to a wide number and variety of microbes, environmental pollutants, and food antigens. Atopy and passive smoke may significantly affect immune responses, mainly in children. The aim of the present study was to investigate whether passive exposure to tobacco smoke and/or atopy could affect immunoglobulin production by adenoidal lymphocytes in a cohort of children presenting with adenoid hypertrophy. A total of 277 children (151 males and 126 females; median age 5.5 years), with adenoidal hypertrophy requiring adenoidectomy and or adeno-tonsillectomy, were consecutively enrolled in the study. Adenoid mononuclear cells were in vitro stimulated with LPS or CpG. When considering both the presence of smoke exposure and atopy, we observed that the CpG-induced decrease in IgA and IgM production was significantly associated with this combination of risk factors. In the T-independent immunoglobulin production assay we found a positive association between the two risk factors and IgA and IgM production. In particular, the presence of both risk factors, showed a significant increase in IgA and IgM production after stimulation. In conclusion, this is the first study that investigated the in vitro adenoidal B cell response after different stimuli in children, also evaluating possible exposure to passive smoke and/or an atopic condition.

Microbiological profile of adenoid hypertrophy correlates to clinical diagnosis in children

Objective. Adenoid hypertrophy is a common condition in childhood, which may be associated with recurring acute otitis media (RAOM), otitis media with effusion (OME), and obstructive sleep apnea syndrome (OSAS). These different clinical characteristics have some clinical overlap; however, they might be explained by distinct immunologic and infectious profiles and result in various histopathologic findings of adenoid specimens. Methods. A total of 59 children with adenoid hypertrophy undergoing adenoidectomy were studied. Three series of identical adenoid specimens were processed to hematoxylin-eosin (H.E.) and Gram staining and to respiratory virus specific real-time PCR, respectively. Results. According to the clinical characteristics, patients were recruited into three groups: RAOM (n = 25), OME (n = 19), and OSAS (n = 15). Bacterial biofilms were detected in 21 cases, while at least one of the studied respiratory viruses was detected in 52 specimens. RAOM cases were significantly associated with biofilm existence (n = 20, P < 0.001). In contrast, OME group was characterized by the absence of bacterial biofilm and by normal mucosa. Showing a statistically significant correlation, all OME cases were positive for human bocavirus (HBoV, P < 0.001). Conclusions. Bacterial biofilms might contribute to the damage of respiratory epithelium and recurring acute infections resulting in RAOM. In OME cases persisting respiratory viruses, mainly HBoV, can cause subsequent lymphoid hyperplasia leading to ventilation disorders and impaired immunoreactivity of the middle ear cleft.

Cellular immune response of adenoidal and tonsillar lymphocytes to the P6 outer membrane protein of non-typeable Haemophilus influenzae and its relation to otitis media

Cellular immune responses to the P6 outer membrane protein of non-typeable Haemophilus influenzae (NTHi) were determined in vitro by measuring immunoglobulin (Ig) secreting cells and lymphocyte proliferation in adenoidal and tonsillar lymphocytes from 19 children. Preliminary tests showed that P6 did not stimulate naive cells such as cord blood lymphocytes, but did stimulate sensitized cells in adenoids and tonsils. Cellular proliferation was significantly higher in adenoidal lymphocytes than in tonsillar lymphocytes (median: quadratile of stimulation index = 3.7:2.3-5.5 vs. 1.2:1.0-2.1, p < 0.02). A comparison between children with or without otitis media revealed that proliferative responses to P6 of adenoidal lymphocytes from children with otitis media were significantly decreased (2.0:1.8-3.6 vs. 3.7:2.3-5.5, p < 0.04). P6-specific antibody secreting cells were identified in a total of 14 adenoids and the number of cells secreting IgA was decreased in the otitis media group compared to controls (median: quadratile/10(6) cells = 435:359-499 vs. 755:593-1870, p < 0.05). Cultivation with P6 stimulated IgA secretion in children without otitis media, while no response was seen in children with otitis media (median: quadratile/10(6) cells = 1323:915-2410 vs. 2240:1900-2830, p < 0.02). These preliminary data demonstrate that lymphocytes from adenoids and tonsils recognize P6 as a specific antigen and that the adenoid is the more reactive of the two organs. Impaired P6-specific cellular immune responses of adenoids in children with otitis media may explain the recurrent nature of otitis media due to NTHi in the otitis prone population.

Th1/Th2 cytokine profiles in the nasopharyngeal lymphoid tissues of children with recurrent otitis media

The cytokine profile in adenoidal lymphoid tissue was studied in 22 patients. Lymphocytes from adenoid tissues and peripheral blood were submitted for cytokine assays using an enzyme-linked immunosorbent assay kit for interferon-gamma, interleukin (IL)-2, IL-4, IL-5, IL-6, and IL-10. Adenoidal lymphocytes appear to produce significantly less Th1 cytokines (IL-2, interferon gamma) compared to the patient's peripheral blood lymphocytes, whereas IL-4 and IL-5 (Th2 cytokines) appear to be synthesized to the same extent as, if not slightly more than, in the homologous peripheral blood lymphocytes. Because the relationship between Th1 and Th2 cytokines is extremely important in modulating the immune response, it is advisable to determine the role of the cytokine profiles of T-lymphocytes in the nasopharynx and its relationship to the development of inflammation of the eustachian tube and middle ear.

Spontaneous immunoglobulin production by adenoidal and tonsillar lymphocytes in relation to age and otitis media with effusion

Spontaneous immunoglobulin (Ig) production by autologous adenoidal and tonsillar lymphocytes cultured without any mitogen was measured by an enzyme-linked immunosorbent assay (ELISA) in 18 children with or without otitis media with effusion (OME). Both IgG and IgA levels synthesized by adenoidal or tonsillar lymphocytes significantly increased with age. The average concentrations of IgG and IgA produced by adenoidal lymphocytes from children with OME were significantly lower than those from children without OME. Adenoidal lymphocytes produced IgG and IgM at significantly lower levels than autologous tonsillar lymphocytes did in children with OME. In contrast, no significant difference between adenoidal and tonsillar lymphocytes was seen on Ig production for any isotypes in children without OME. These results may indicate immunological impairment of the adenoids associated with OME.

Flow cytometric quantification of lymphocyte subpopulations and immunoglobulin-containing cells in adenoid tissue in relation to secretory otitis media and age

This study was designed to identify differences in the immunological reactions in adenoid tissue between children suffering from chronic secretory otitis media (SOM) and control children without ear disease. Cell populations were identified using monoclonal antibodies and flow cytofluorometry to facilitate quantitative comparisons. A modification of the FOG method was developed to quantify lymphocytes with intracellular IgG and IgA. Immunological screening was done in the first part of the study. No significant differences were found between the groups regarding cells positive for CD3, CD4, CD8, CD20 or CD25. A significantly higher number of PCA-1 positive cells (presumably plasma cells) were found in the SOM group. The second part of the study concentrated specifically on cells containing IgG or IgA. No statistically significant differences in number of positive cells were found between the groups. When we related the percentage of positive cells to age, a statistically significant decrease with age for IgA-positive cells was found in the SOM group but not in the control group. This result supports the hypothesis that SOM is associated with an immunological reaction that influences immunoglobulin production in adenoid tissue.