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

Dendritic cells and lymphocyte subpopulations of the adenoid in the pathogenesis of otitis media with effusion

OBJECTIVE

To assess dendritic cells and lymphocyte subpopulations of adenoid and peripheral blood in patients with adenoid hypertrophy and otitis media with effusion (OME). To explain the influence of immunological status of adenoid on the development of OME.

METHODS

The examined group covered 123 surgically treated patients due to adenoid hypertrophy (39 children with coexisting OME). Preoperative clinical examination included anamnesis and otorhinolaryngological examination with nasofiberoscopy, videootoscopy and assessment of the hearing organ. The material of the study were surgically removed adenoids and peripheral blood samples prepared and then analyzed by the means of tri-colour flow cytometry. The obtained results were statistically analyzed.

RESULTS

Significant differences between patients with adenoid hypertrophy with coexisting OME and children without OME concerning CD19+CD69+, CD3+CD69+, CD4+CD69+CD8+CD69+ and CD19+CD25+ cells were observed. No statistical differences were revealed in the blood of patients with and without OME. Several statistical differences were noted between the adenoid and peripheral blood in patients with otitis media with effusion concerning BDCA-2+/CD123+ cells, CD3+ and CD19+ lymphocytes with the markers of their activation.

CONCLUSIONS

The adenoid is involved in local immune response regardless of constitutional immunological mechanisms in patients with OME coexisting with adenoid hypertrophy. Significantly lower percentage of CD3+CD69+, CD4+CD69+, CD8+CD69+ and CD19+CD69+ cells of adenoid in patients with OME attests to reduced T-cells activation of the adenoid in relation to patients without OME.

Difference in cytokine production and cell activation between adenoidal lymphocytes and peripheral blood lymphocytes of children with otitis media

We evaluated the immunological potential of adenoidal lymphocytes from children with recurrent otitis media. Interleukin-4 release and CD69 expression were lower in adenoidal lymphocytes than in peripheral blood lymphocytes (PBL). Our results suggest that there may be a difference between the immunological potential of adenoidal lymphocytes and that of PBL in children with otitis.

Lymphocyte subpopulations in middle ear effusions: flow cytometry analysis

OBJECTIVE

The aim of this study was to identify lymphocyte subpopulations in middle ear effusions, peripheral blood, and adenoids in children suffering from otitis media with effusion.

SETTING

Tertiary referral center.

PATIENTS

Thirty-three children (55 ears) undergoing myringotomy for otitis media with effusion.

METHODS

CD3, CD4, CD8, CD19, and natural killer cell populations were investigated in middle ear effusion, peripheral blood, and adenoids using a three-color monoclonal antibody and flow cytometry method for quantitative estimation.

RESULTS

T cells (CD3) are dominating lymphocytes in middle ear effusion. Among T lymphocytes, the majority are those of the helper type (CD4). The dominating isoform among CD4 lymphocytes are memory cells (CD4CD45RO); among CD8 lymphocytes, naive cells (CD8CD45RA). The percentage of CD4 cells, CD8 cells, and the CD4/CD8 ratio was significantly higher in middle ear effusions than in blood. The percentage of memory CD4 lymphocytes and naive CD8 lymphocytes was significantly lower in the middle ear effusion. Lymphocyte subsets were compared between 22 pairs of effusions from each patient. The percentage of each type of cell did not differ significantly.

CONCLUSION

The results of this study indicate local regulation of the lymphocyte profile in middle ear effusions and the same phase of immune response in two ears of the same patient.

Lymphocyte subpopulations in hypertrophied adenoid in children

Adenoid hypertophy is a common feature of childhood. It is currently accepted that it is caused by the antigen-stimulated increased activity of lymphocyte B (D. Bani, O. Gallo, O. Fini-Storchi, Intraepithelial lymphocyte subpopulations and dendritic accessory cells in normal and hypertrophic adenoids, Laryngoscope 10 (1994) 869-873). The adenoid decreases its size with age but the accompanying function alterations are not fully understood (L. Zawadzka-Glos, M. Chmielik, M. Wasik, Cell mediated response in hypertrophied tonsils in children, Nowa Pediatr. 4 (1997) 12-13). The understanding of the adenoid structure that undergoes some changes during the growth period is essential for evaluation of indications for adnoidectomy and assessment of its potential results. The aim of this study was to evaluate lymphocyte subpopulations in adenoid according to age. The analysed material was adenoids removed on the grounds of hypertrophy, which caused obstructive symptoms and/or otitis media with effusion onset. In the present study, we did not find any statistically significant differences among lymphocytes B, Th, and Ts subpopulations, respectively, in the adenoids of any of the age groups. We have found a statistically significant CD3(+) HLA-DR(+) cell percentage decrease in the group of children from 5 to 10 and above 10 years of age, respectively. We have also found a statistically significant increase in the percentage of NK (CD3(-) CD16(+) 56(+)) lymphocytes in relation to age. On the grounds of the current study, it may be stated that some changes in lymphocyte subpopulations in the adenoid take place with age.

Increased occurrence of IgE+ and FcepsilonRI+ cells in adenoids from atopic children

BACKGROUND

To examine the influence of atopy on the different cell populations in adenoids, we investigated the presence of IgE+ cells, cells expressing the high-affinity receptor for IgE (Fc(epsilon)RI), and various other cell populations in adenoid tissue, in atopic and nonatopic children with otitis media with effusion (OME) or adenoid hyperplasia (AH).

METHODS

Cryostat sections of adenoids from 14 atopic and 16 nonatopic children suffering from long-lasting OME (n=15) or obstructive AH (n=15) were investigated with immunohistochemical markers for T-cell subsets, mast cells, eosinophils, plasma cells, CD25, CD1a, IgE, and Fc(epsilon)RI.

RESULTS

Sensitization to allergens was correlated to an increase of IgE+ cells in the epithelium (P<0.01), the extrafollicular area (P<0.0001), and the follicles (P<0.001) of the adenoids and an increase of Fc(epsilon)RI+ cells in the extrafollicular area (P<0.01). A minority of the IgE+ cells were plasma cells. No significant differences in cells stained for IgE, Fc(epsilon)RI, or the other markers were observed between patients with OME and AH.

CONCLUSIONS

Atopy is associated with increased numbers of IgE+ and Fc(epsilon)RI+ cells in adenoids irrespective of whether the child has OME or AH.

Increased levels of IL-5 positive peripheral blood eosinophils and lymphocytes in mild asthmatics after allergen inhalation provocation

BACKGROUND

In allergic inflammation eosinophils and TH2-like lymphocytes are supposed to be the major effector cells and considered to contribute as cellular source of the key cytokine interleukin (IL)-5.

OBJECTIVE

The purpose of this study was to enable detection of IL-5 containing leucocytes and to investigate whether the number of these cells in the blood circulation differed between healthy and asthmatics before and after allergen provocation.

METHODS

The distribution of intracellular IL-5 in human peripheral blood eosinophils (PBE) and lymphocytes (PBL) has been investigated using fixation and cell membrane permeabilization with octyl-glucopyranoside, the FOG-method, and flow cytometry. The intracellular staining was performed on leucocytes without any prior purification and in vitro stimulation. The specificity of IL-5 binding to intracellular compartment of both PBE and PBL was confirmed by complete inhibition with human recombinant IL-5.

RESULTS

Preformed intracellular IL-5 was detected in the main population of PBE (> 70%) in both healthy individuals and asymptomatic patients. Moreover, preformed intracellular IL-5 was also detected in 4.8% and 2.4% of PBL from healthy individuals and asymptomatic patients, respectively. There was a correlation between the absolute number of PBE and IL-5 positive PBE. In patients with pollen-related asthma, the number of IL-5 positive PBE and PBL increased significantly 24 h after an allergen inhalation provocation (P < 0.05). In the healthy control group no differences regarding IL-5 positive PBE and PBL were obtained pre- and post-allergen challenge.

CONCLUSIONS

In patients with mild allergic asthma, but not in healthy individuals, allergen provocation induces an increased absolute number of IL-5 positive PBE and PBL. The reason for the relatively high number of IL-5 positive PBL is unclear, but a plausible explanation might be that other lymphocyte subsets besides CD4+ TH2 can produce IL-5. However, enumeration of IL-5 positive leucocytes may be used as an activity marker and also be a useful tool in monitoring the inflammation in asthma.

Immune responses of adenoidal lymphocytes specific to Haemophilus influenzae in the nasopharynx

OBJECTIVES

Investigate immune responses of adenoidal lymphocytes against outer-membrane protein P6 purified from nontypeable Haemophilus influenzae (HI). Clarify the role of adenoids in regulating the colonization of HI in the nasopharynx.

STUDY DESIGN

Microbiological and immunological examinations of adenoids obtained from 21 children, 15 boys and five girls, from 1 to 13 years of age (median, 5 y), suffering from adenoidal hypertrophy complicated by otitis media with effusion (OME).

METHODS

The incidence of HI in adenoids was compared with the number of P6-specific immunoglobulin (Ig) A-secreting cells in adenoids, determined by enzyme-linked immunoassay.

RESULTS

Quantitative culture assay showed significant correlation between the numbers of HI in adenoids and those in nasopharyngeal secretions (NS). In children aged 5 years and younger, the numbers of P6-specific IgA-secreting cells in adenoids were significantly correlated with IgA antibody titers in NS (r = 0.68, P < .05). The numbers of P6-specific IgG- and IgA-secreting cells were lower in children aged 6 years and older than in children aged 5 years and younger. Furthermore, the number of P6-specific IgA-secreting cells was significantly increased in HI-negative subjects when compared with HI-positive subjects (P < .05).

CONCLUSIONS

Adenoids play an important role as an effector site of the mucosal immune system in the upper respiratory tract. IgA immune responses in adenoids are responsible for the clearance of HI from the nasopharynx.

T-cell subsets in adenoids and peripheral blood related to age, otitis media with effusion and allergy

Adenoids and peripheral blood samples from 29 children (20-120 months of age) undergoing adenoidectomy for long-standing otitis media with effusion (OME) (n=16) or obstructive adenoid hyperplasia (n=13) were investigated by flow cytometry for their T-lymphocyte profile. Eleven of the enrolled children were allergic to inhalant and/or food allergens. For the whole group, the percentage of helper T cells belonging to the memory phenotype (CD4+/CD45RO+ cells) was significantly higher in adenoids than in blood (p<0.0001), while the same cell category increased with age in peripheral blood (p<0.01). A highly significant negative regression (p<0.001) was found between age and the percentage ratio of CD4+ cells that were CD45RO+ in adenoids and blood. Allergic children had a higher CD4+/CD8+ ratio for cells expressing CD45RO+ (p<0.05) in adenoids. The results of this study indicate that adenoids participate in the development of an immunological memory. Our findings support a relationship between allergy and memory cells in adenoids.

B- and T-lymphocyte subpopulations in the adenoids of children with otitis media

Adenoid hyperplasia is connected with the pathogenesis of otitis media in children, as implicated by the residence of pathogens causing otitis media in adenoids, and by the beneficial effect of adenoidectomy. We have quantitated the proportions of certain T- and B-lymphocyte subsets in the adenoids by three-color flow cytometry. Three groups were studied: 1) children with persistent effusion in the middle ear (pOME), 2) children with recurrent otitis media with no effusion in the middle ear at the time of surgery (rAOM), and 3) children with adenoid hyperplasia without otitis media (AH) presenting either with snoring or upper respiratory tract infections. B lymphocytes comprised on average 64, 66 and 58% of all mononuclear cells in the respective patient groups. The majority of the B lymphocytes were of the follicular mantle zone phenotype expressing surface IgD (on average 69, 67 and 70% of all B lymphocytes in the respective patient groups). Almost one third of the B lymphocytes were of the germinal center cell phenotype, expressing CD38 but negative for surface IgD (on average 29, 30 and 25% in the respective patient groups). CD3+ T lymphocytes comprised 33, 33 and 40%, respectively, of all mononuclear cells, and the average CD4+/CD8+ ratio was 5.2, 4.9 and 5.7, respectively. No statistically significant differences between the patient groups were seen in these T- and B-lymphocyte subpopulations. These results suggest that the relative sizes of the germinal center, follicular mantle and interfollicular compartments of the adenoids do not correlate with the disease status of the middle ear cavity.

Distribution of plasma cell markers and intracellular IgE in cell line U266

The IgE-producing plasma cell line U266 was used to study intracellular IgE and the distribution of the plasma cell markers CD38 and PCA-1. We found two separate clusters of U266 based on the differences in their light scatter properties in the flow cytometer. One cluster displayed high scatter signals (high SS), whereas the other showed low scatter signals (low SS). Most (75%) of the cells in the low SS cluster were positive for intracellular IgE. In contrast, high SS cells had a higher expression of surface IgE and a considerably lower proportion of these cells expressed intracellular IgE. Different patterns of expression of the plasma cell antigens CD38 and PCA-1 were observed. While the low SS cluster displayed a high (76%) expression of PCA-1 and a low (5%) CD38 expression, the high SS cluster expressed 21 and 42%, respectively. About 2/3 of the cells in the low SS cluster appeared to be in the G1 phase of the cell cycle while 1/3 were in the S/G2 phase. In the high SS cluster the opposite distribution (2/3 in S/G2) was observed. Taken together our results indicate an association between cell cycle stages, expression of intracellular IgE and plasma cell markers.