The Physiology and Immunology of the Pharyngeal Lymphoid Tissue

A Comparative Analysis of Outcomes of Conventional Cold Dissection Versus Laser Tonsillectomy in Pediatric Cases in a Tertiary Care Hospital in Haryana

Tonsillectomy is one of the commonest ENT procedures done in paediatric population, the technique of which has evolved over years to decrease the morbidity associated with the surgery. This prospective randomized comparative study is done to evaluate the efficacy of two different techniques of this surgery, conventional cold dissection and laser tonsillectomy based on operative time, blood loss, post-operative pain and occurrence of secondary complications. The study was done in 68 patients of paediatric age group, 34 in each group underwent cold dissection and laser tonsillectomy. Operative time and bleeding were significantly low for laser group. Pain score was comparable in early post-operatives days, but was high towards the end of first week. Our study reported only one incidence of complication in the form of a secondary bleeding.

Evaluation of carotid intima-media thickness and carotid arterial stiffness in children with adenotonsillar hypertrophy

BACKGROUND

Adenotonsillar hypertrophy can produce cardiopulmonary disease in children. However, it is unclear whether adenotonsillar hypertrophy causes atherosclerosis. This study evaluated carotid intimamedia thickness and carotid arterial stiffness in children with adenotonsillar hypertrophy.

METHODS

The study included 40 children with adenotonsillar hypertrophy (age: 5-10 years) and 36 healthy children with similar age and body mass index. Systolic blood pressure, diastolic blood pressure, and pulse pressure were measured in all subjects. Carotid intima-media thickness, carotid arterial systolic diameter, and carotid arterial diastolic diameter were measured using a high-resolution ultrasound device. Based on these measurements, carotid arterial strain, carotid artery distensibility, beta stiffness index, and elasticity modulus were calculated.

RESULTS

Carotid intima-media thickness was greater in children with adenotonsillar hypertrophy (0.36±0.05 mm vs. 0.34±0.04 mm, P=0.02) compared to healthy controls. Beta stiffness index (3.01±1.22 vs. 2.98±0.98, P=0.85), elasticity modulus (231.39±99.23 vs. 226.46±83.20, P=0.88), carotid arterial strain (0.17±0.06 vs. 0.17±0.04, P=0.95), and carotid artery distensibility (13.14±3.88 vs. 12.92±3.84, P=0.75) were similar between children with adenotonsillar hypertrophy and the healthy controls.

CONCLUSIONS

The present study revealed increased carotid intima-media thickness in children with adenotonsillar hypertrophy. The risk of subclinical atherosclerosis may be higher in children with adenotonsillar hypertrophy.

Tonsillar hyperplasia and recurrent tonsillitis: clinical-histological correlation

Hypertrophy and recurrent tonsillitis are common indications of tonsillectomy. However, the pathological reports are similar, regardless of clinical aspects.

Objective

Search for histopathological changes that differentiate palatine tonsils operated because of hypertrophy vis-à-vis those operated because of recurrent tonsillitis.

Method

A prospective cross-sectional descriptive study involving 46 children divided into group I - 22 with hypertrophy; and group II - 24 with recurrent tonsillitis, in the period between 2010 and 2012, in a public hospital. We evaluated clinical and histopathological features (lymph follicles, germinal centers, fibrosis, necrosis, reticulation, infiltration by plasma cells and neutrophils).

Results

The patients' ages ranged between 2 and 11 years (5.17 ± 2.28). In group I, half of the patients had had the latest infection at seven months or more, and all with obstruction degree greater than 3 (≥ 50%). In group II, all had had the latest infection at less than seven months, and most with obstruction degree below 4 (≤ 75%). There was a statistically significant difference in the degree of obstruction (p = 0.0021) and number of germinal centers (p = 0.002) was higher in group I.

Conclusion

This study suggests that the number of germinal centers is the only histopathological criterion that can be used to differentiate the two groups.

Short and long term impact of adenotonsillectomy on the immune system

Palatine and pharyngeal tonsils are immune reactive lymphoid organs that manifest specific antibodies and B/T-cell activity to respond to a variety of antigens. They perform humoral and cellular immune functions. The possible effects of adenotonsillectomy upon the immune system remain controversial.

Objective

To study the short and long-term impacts of tonsillectomy upon the cellular and humoral immunity of children.

Method

This longitudinal prospective study included 29 children referred to adenotonsillectomy for adenotonsillar hypertrophy. Serum IgA, IgM, and IgG and lymphocyte counts were analyzed at three points in time: before surgery, 1-2 months after surgery (short term), and 12-14 months after surgery (long term).

Results

TCD4+ cell counts were significantly increased shortly after surgery. IgA and IgG values were significantly reduced in the long run, but were within normal ranges for this age group.

Conclusion

This study indicated that adenotonsillectomy does not pose negative short or long term impacts upon the cellular and humoral immunity of children submitted to the procedure.

Tonsillitis, peritonsillar and lateral pharyngeal abscesses

Oral and maxillofacial surgeons are occasionally called on to diagnose, treat, and rule out peritonsillar abscesses. In this article, the anatomy of the peritonsillar area, its contents, surgical approaches, and possible complications are discussed.

Evaluation of long-term impacts of tonsillectomy on immune functions of children: a follow-up study

OBJECTIVE

The purpose of this follow-up study was to investigate the long-term effects of tonsillectomy in comparison with their short-term results.

PATIENTS AND METHODS

We successfully retrieved 20 out of our previously reported 37 patients who underwent tonsillectomy in our clinic 54 months ago. The blood levels of CD3+, CD4+, CD8+, CD19+, CD25+ and CD16++56+ (cellular immunity), and IgG, IgA, IgM, C3 and C4 (humoral immunity) were determined and compared with their previously reported short-term respective values.

RESULTS

There were no statistically significant differences between the short-term (1 month) and long-term (54 months) values of IgA, IgG, IgM and C4 levels of the patients (P>0.05). There was a slight but statistically significant decrease in complement factor C3 value compared to its the early-stage value (P<0.05) but this was not significantly different from age-matched healthy controls (P>0.05). The levels of CD4+ and CD19+ were higher and the levels of CD16++56+ and CD25+ were lower in the late-stage (54 months) compared to their early-stage values (P<0.05). When the long-term immune parameters of the tonsillectomized patients were compared with aged-match healthy controls, there were no significant differences between the levels of immunoglobulins, complements and lymphocytes (IgA, IgG, IgM, C3, C4, CD3+, CD4+, CD8+, CD19+, CD25+, CD16++56+) (P>0.05).

CONCLUSION

The results of this long-term follow-up study indicate that tonsillectomy do not compromise the immune functions of children as humoral and cellular immunity of patients recovered compared to their early-stage immune status (1 month), as they have similar immune capacity compared to their age-matched healthy controls at both early- and late-stages. Although a small sample of patients enrolled, our results are of importance with respect to the reassuring in settling the widely held urban myth that tonsillectomy compromises life long immunity.

Distribution of leucocyte subsets in the canine pharyngeal tonsil

This report describes the distribution and nature of lymphoid tissue in the nasopharyngeal mucosa of six puppies (mean age+/-SD, 0.3+/-0.25 years) and eight adult dogs (mean age+/-SD, 8.8+/-2.67 years) without respiratory disease. A non-encapsulated area of organized mucosa-associated lymphoid tissue was observed in the caudal part of the posterior wall of the nasopharynx, distal to the openings of the auditory tubes. This structure was consistent with the pharyngeal tonsil and was microscopically more extensive in puppies than in adult dogs. Histochemistry and immunohistochemistry were used to characterize and enumerate the leucocyte subsets in this part of the nasopharynx. Mast cells were found immediately beneath the respiratory epithelium but were also scattered in the glandular and muscular tissue. IgA(+) plasma cells outnumbered IgG(+) and IgM(+) plasma cells, especially in the glandular tissue. All classes of plasma cells were present in significantly greater numbers in adults than in puppies. MHC class II(+) cells were mainly observed in areas containing diffuse and follicular aggregates of lymphoid cells. Both MHC class II(+) cells and CD1c(+) cells with a dendritic morphology were predominantly found immediately beneath or within the epithelium, and cells expressing these markers were more abundant in puppies than in adult dogs. The anti-L1 marker labelled low numbers of cells with a neutrophilic morphology, which were significantly more abundant in puppies than in adult dogs. The majority of lymphoid cells were CD3(+) T lymphocytes and these were particularly abundant in areas containing aggregates of lymphoid cells; CD4(+), CD8(+) and TCR alphabeta(+) cells had the same distribution as the CD3(+) cells. CD4(+) cells were more numerous than CD8(+) cells. The quantitative and qualitative data obtained will enable comparisons to be made with similar studies in dogs suffering from nasopharyngeal diseases, or when the local immune system needs to be investigated.

Profile of hospitalizations due to otorhinolaryngologic morbidity requiring surgical treatment. Brazil, 2003

Aim

To analyze the profile of the surgical procedures related to otorhinolaryngology in Brazil in the year 2003.

Study Design

This was an observational, descriptive, cross-sectional study.

Methods

We analyzed 80,030 surgical procedures performed in 27 Brazilian States during the period from January to December 2003. The data were obtained from the Hospital Information System of the Ministry of Health. The inclusion factor was a surgical procedure in otorhinolaryngology (ORL). All files were processed with the TABWIN software.

Results

In 2003, 80,030 ORL-related surgical procedures were performed in Brazil. The Southeast region had the largest number of procedures (53.08%), followed by the South and Northeast regions (19.6% and 15.6%, respectively). Regarding the group of procedures, surgeries of the pharynx represented 45% of ORL procedures. Procedures of high complexity were more numerous in the ear surgery group. Regarding the distribution of the type of attending institution, the highest concentration of surgical procedures occurred in philanthropic hospitals, followed by state and university public hospitals. The table adopted by SUS for payment of ORL surgical procedures has not been updated for the procedures currently performed, with the consequent inappropriate notification of some types of surgery.

Conclusion

Knowledge about the profile of surgical hospitalizations related to ORL permits the identification of the peculiarities of the different regions that can help health-managing authorities to make decisions in order to guarantee the principles recommended by SUS regarding access to health services.

Adenoidectomy and/or tonsillectomy in childhood is not associated with atopic disease later in life

OBJECTIVE

To investigate the association between adenoidectomy and/or tonsillectomy in childhood and asthma, allergic rhinitis (AR), and eczema in adolescence.

METHODS

Longitudinal birth cohort study of 1328 members born in the city of Nijmegen. Information on ear-nose-throat surgery was documented at 2, 4, and 8 years of age. In 1055 cohort members the incidence of asthma, AR, and eczema at 21 years of age was determined using the International Study of Asthma and Allergic disease in Childhood Core Questionnaire. To analyse the association between adenoidectomy and/or tonsillectomy in childhood and asthma, AR, and eczema at age 21 years, relative risks (RR) were calculated.

RESULTS

Six hundred and ninety-three (66%) members completed the questionnaire at age 21 years, of whom 104 (15%) had undergone adenoidectomy and/or tonsillectomy and 262 (38%) reported atopic disease. Children who underwent adenoidectomy and/or tonsillectomy before the age of 8 years were not more likely to develop asthma, AR, or eczema at the age of 21 years than children who did not; RR 0.93 (95% confidence limits (CL) 0.52-1.64), RR 0.94 (CL 0.68-1.30), and RR 1.00 (CL 0.59-1.68), respectively.

CONCLUSIONS

Our data show no association between adenoidectomy and/or tonsillectomy in childhood and the incidence of atopic disease in young adults.

Palatine tonsils in smoker and non-smoker patients: a pilot clinicopathological and ultrastructural study

BACKGROUND

Tobacco smoke is a well-known source of toxic, mutagenic and carcinogenic agents. The aim of the present preliminary study was to investigate the effects of cigarette smoking on lymphoid and non-lymphoid tonsillar tissue.

METHODS

The study group consisted of 12 smoker and 10 non-smoker patients complaining recurrent tonsillitis. Clinical data, histological findings and scanning electron microscopic analyses were considered. To the best of our knowledge, such an approach has not been previously adopted in a similar experimental model.

RESULTS

Smoker patients showed a longer history of recurrent tonsillitis, difficulties in clinical management and evident morphostructural changes than non-smokers.

CONCLUSIONS

These preliminary results suggest a possible interference of cigarette smoking with the therapy response as well as a possible role of tobacco smoke in impairment of inflammatory response. Results are critically analysed and discussed. Literature data on this subject are reviewed.

Early stage impacts of tonsillectomy on immune functions of children

OBJECTIVE

The purpose of this study was to investigate the changes in the humoral and cellular immunity of patients with chronic tonsillitis before and 1 month after tonsillectomy.

PATIENTS AND METHODS

37 patients scheduled for tonsillectomy were enrolled in this study. The levels of CD3+, CD4+, CD8+, CD19+, CD25+ and CD16+ + 56+ were measured for cellular immunity, and levels of IgG, IgA, IgM, C3 and C4 were measured for humoral immunity in blood samples taken from these patients before and 1 month after the operation.

RESULTS

The levels of CD3+, CD8+ and CD19+ were reduced in post-operative period as compared to pre-operative period but this was not statistically significant (P > 0.05). However it was found that the level of CD4+ was significantly increased while the level of CD25+ was reduced (P < 0.05) in the post-operative period. There were statistically significant differences between pre- and post-operative levels of immunoglobulins, C3 and C4, which were decreased after tonsillectomy (P < 0.05), but these levels were comparable with those of the control group.

CONCLUSION

The results from the present study indicate that humoral and cellular immunity of patients undergoing tonsillectomy were decreased in the early period and came to normal later. The cellular and humoral immune responses are stimulated in patients with tonsillitis, and tonsillectomy removes this stimulus without negatively affecting the patient's immune functions.

Is immune system influenced by adenotonsillectomy in children?

OBJECTIVE

Tonsils and adenoids are lymphoid tissues that are located in the pharynx and play an important role against invading antigens of the upper respiratory tract. The present study analyses serum immunoglobulin levels and peripheral blood (PB) lymphocyte subsets in children, 24-48 h prior to and 4-6 weeks after adenotonsillectomy, in order to determine early effects of adenotonsillectomy on the immune system.

METHODS

The study population consists of 15 children (aged 4-10 years) who underwent adenotonsillectomy because of adenoidal hypertrophy and chronic tonsillitis and 15 age-matched healthy children without a history of adenotonsillectomy. Serum IgG, IgA and IgM levels were measured by nephelometry. PB lymphocyte subsets were analysed by using monoclonal antibodies and flow cytometry.

RESULTS

Children with chronic tonsillitis have increased levels of CD19+ B lymphocytes compared to healthy controls in the pre-operative period. The percentage of B lymphocytes bearing CD23 was found to be significantly higher in patients, most likely representing in vivo B lymphocyte activation due to chronic antigenic stimulation. After the adenotonsillectomy, despite ongoing B lymphocyte activation, CD8+ T lymphocyte levels increased and B cell levels returned to normal. A slight decrease in serum IgG, IgA and IgM levels was detected in the post-operative period compared to prior levels.

CONCLUSION

Adenotonsillectomy performed in children leads to alterations that may reflect a compensatory response of the developing immune system after the removal of the lymphoid tissue in the setting of chronic antigenic stimulation. However, these changes do not cause significant immune deficiency.

Implication of immunological abnormalities after adenotonsillotomy

The adenoids and tonsils are thought to be essential parts of the system protecting organism against pathogens invading the upper respiratory tracts. Human adenoids and tonsils are known to be immunologically reactive lymphoid organs, which manifest specific antibodies and B and T cells activity in response to variety of antigens carrying out the functions of humoral and cellular immunity. The purpose of the study was to observe the changes in systemic immunity in children with hypertrophy of adenoids and tonsils treated in Department of Laryngology, Children's Hospital in Warsaw in period 1994-1999. The study comprised 80 patients (33 girls and 47 boys, aged from 3 to 14 years, mean age 6.8 years) with diagnosed hypertrophy of adenoids and tonsils. The diagnosis of hypertrophy of adenoids and tonsils was based on characteristic history and laryngological examination. All patients were scheduled for adenotonsillotomy. The control group comprised 40 people (14 girls and 26 boys, aged from 3 to 15 years, mean age 7.6 years) without history of the recurrent upper tract infections. In all patients we carried out following examinations: serum levels of immunoglobulins A, G, M (humoral immunity); percentage of T lymphocytes (CD3); percentage of T helper (CD4) and T cytotoxic (CD8) lymphocytes (cellular immunity) and delayed cutaneous hypersensitivity-Multitest CMI (cell mediated immunity). Our study demonstrate that in children with hypertrophy of adenoids and tonsils exist changes in the immunological parameters. The observed changes appear not only locally but also generally. In the early period after adenotonsillotomy there was statistically significant decrease of the values of humoral and cellular immunity parameters. However, 6 months after operation we observed normalization of examined immunological parameters. We think that the examinations of parameters of immunological system (humoral and cellular) are necessary before planned adenotonsillotomy.

Human nasopharyngeal-associated lymphoreticular tissues. Functional analysis of subepithelial and intraepithelial B and T cells from adenoids and tonsils

Subepithelial and intraepithelial lymphocytes of human adenoids and tonsils were characterized and directly compared to determine the potential contribution of these tissues to mucosal and systemic immune responses. The distribution of T and B cell subsets, cytokine patterns, and antibody (Ab) isotype profiles were similar for adenoids and tonsils. Both tissues contained predominantly B cells ( approximately 65%), approximately 5% macrophages, and 30% CD3(+) T cells. The T cells were primarily of the CD4(+) subset ( approximately 80%). Tonsillar intraepithelial lymphocytes were also enriched in B cells. The analysis of dispersed cells revealed a higher frequency of cells secreting IgG than IgA and the predominant Ig subclass profiles were IgG1 > IgG3 and IgA1 > IgA2, respectively. In situ analysis also revealed higher numbers of IgG- than IgA-positive cells. These IgG-positive cells were present in the epithelium and in the subepithelial zones of both tonsils and adenoids. Mitogen-triggered T cells from tonsils and adenoids produced both Th1- and Th2-type cytokines, clearly exhibiting their pluripotentiality for support of cell-mediated and Ab responses. Interestingly, antigen-specific T cells produced interferon-gamma and lower levels of interleukin-5. These results suggest that adenoids and tonsils of the nasopharyngeal-associated lymphoreticular tissues represent a distinct component of the mucosal-associated lymphoreticular tissues with features of both systemic and mucosal compartments.

Immunoglobulin-secreting cells in the surface secretion on the pharyngeal tonsils

As B-lymphocytes on the pharyngeal tonsils constitute a considerable part of the leukocytes in the surface secretion, and their biological role is obscure, we explored their possible function with respect to immunoglobulin production. Twenty children scheduled for routine adenoidectomy participated. Surface secretion from 10 children was analysed for presence of plasma cells and cells from the secretions of the other 10 children were tested in enzyme-linked immunosorbent spot assays (ELISPOT-assays) for their capacity to secrete and produce IgA, IgM and IgG. Plasma cells and cells that secreted IgA, IgM and IgG respectively were present in the secretions of all tested children. In eight of ten children the IgG immunocytes, Ig-producing blasts and plasma cells. outnumbered the IgA immunocytes. The number of immunoglobulin secreting cells (ISCs) was reduced by half or more in cell suspensions exposed to the reversible protein synthesis inhibitor cycloheximide. It is concluded that immunocytes that produce and secrete immunoglobulin are present in the surface secretion on the pharyngeal tonsils. The production represents an addition to the immunoglobulins transported to the secretion by the poly-Ig receptor and by passive diffusion. The results shed new light on the pathogenesis of mucosal infections in the upper airways.

Nasopharyngeal tonsil's provision of the surface secretions with immunocytes, a property additional to antigen processing

As we recently found that IgA, IgM, and IgG are produced and secreted by immunocytes present in nasopharyngeal secretions, we tested the hypothesis that B- and T-lymphocytes in the surface secretions are derived from the nasopharyngeal tonsil in an active process. By immunohistochemistry, we found that numerous B- and T-lymphocytes were often accumulated in restricted areas in the epithelium, and some of these cells were demonstrated just beneath the epithelial surface or could be observed protruding into the lumen. A portion of these cells were Ki-67+, indicating clonal expansion and/or immunoglobulin class switching. Analyses of the surface secretions by immunocytochemistry also demonstrated B- and T-lymphocytes, as well as Ki-67+ cells--a finding that indicates that immunologically active cells are transported into the surface secretions. The results imply that there is a substantial migration from the nasopharyngeal tonsil of immunologically active cells into the surface secretions.

Sore throat, tonsillitis, and adenoiditis

Diseases of the adenoids and tonsils are a frequent cause for patients to seek medical attention. A thorough understanding of the disease processes reflected in the adenoids and tonsils and their diagnosis and treatment is an important part of routine care delivery. Diagnostic methodologies and timing of surgical intervention are reviewed along with general considerations relating to the differential diagnosis in adult and pediatric patients.

Characterization of smoking-induced nasopharyngeal lymphoid hyperplasia

The frequency of smoking-induced nasopharyngeal lymphoid hyperplasia in heavy smokers and its potential clinical implications are still unknown. Precise criteria to differentiate this entity from other types of nasopharyngeal lymphoid hyperplasia are needed. A prospective clinicopathological study of smoking-induced nasopharyngeal lymphoid hyperplasia was conducted in 17 heavy smokers. Ten nonsmoking patients, five of them with chronic sinusitis, three with adult-onset adenoid hypertrophy, and two children with adenoidal hypertrophy served as a control group. Both in smokers and in nonsmokers, lymphocytic infiltration of the mucosa was characterized immunohistochemically as T cells. In smokers, semithin (1 micron) sections revealed deformed and migrating cytotoxic lymphocytes in the nasopharyngeal mucosa. The lymphocytes were attached to epithelial, ciliated, and goblet cells, resulting in cell damage. Transmission electron microscopy of biopsies from smokers revealed emperipolesis, characterized by mucosal invasion and epithelial cell damage by an unusual population of migrating T lymphocytes that penetrate them. These findings confirm a direct effect of smoking on the nasopharyngeal lymphoid tissue, which forms part of the immune system. It is concluded that the diagnostic evaluation and therapeutic approach of heavy smokers with otological and airway symptoms should be based on thorough endoscopic examination of the nasopharynx. When the diagnosis is not clear-cut, selective tele-endoscopic biopsy and electron microscopic examination are recommended. This entity should be added to the list of known clinical manifestations of the smoking habit.

The relationship between SIgA and chronic granular pharyngitis

A survey of the SIgA content in saliva, serum and pharyngeal mucosa with lymphoid tissue (PMLT) of chronic granular pharyngitis patients was conducted by a double antibody PEG radio-immune method. These data were compared with those from a healthy control group. Result shows that SIgA in patients with chronic granular pharyngitis had dissociation of saliva, serum and PMLY. There was low salivary SIgA level but higher levels in serum and PMLT. These data suggest that the saliva and serum immunoglobulin pools are under separate regulation.

Development and immunophenotyping of the pharyngeal tonsil (adenoid) in cattle

Immunoperoxidase staining and electron and light microscopy were used to characterize the development of the pharyngeal tonsil in 98 cattle aged between 30 days of gestation and 12 years. The rugae of the pharyngeal tonsil were poorly formed before 95 days of gestation. Microvillous (M) cells associated with intra-epithelial leucocytes (lympho-epithelium) were scattered among ciliated and goblet cells covering most of the surface in post-natal animals. Intra-epithelial leucocytes were rare in fetuses, but ciliated and M cells could be distinguished. Leucocytes of the lamina propria started to accumulate at approximately 120 days of gestation. A loose accumulation of mononuclear cells progressed into a B-cell rich upper and T-cell rich lower layer, with typical lymphoid tissue organization in post-natal animals and lymphoid involution in aged cattle. Primary lymphoid follicles formed at 5 months of gestation, but germinal centres did not form until 2 to 4 weeks after birth. Except for null cells, the relative number of cells staining for each leucocyte phenotype or MHC class II antigen increased with age, especially during the neonatal period. The early development, strategic location and specialized structure of the pharyngeal tonsil suggest an important role in modulating inhaled antigens in cattle. Fetal and neonatal calves had minimal lymphoid tissue priming, as indicated by lack of secondary follicles, low MHC class II expression and few intra-epithelial leucocytes. The phenotypic differences may be relevant to the increased susceptibility of calves to infectious diseases shortly after birth.

Bovine herpesvirus-1-induced pharyngeal tonsil lesions in neonatal and weanling calves

The potential involvement of the pharyngeal tonsil in the pathogenesis of bovine herpesvirus-1 (BHV-1) infection was examined in neonatal and weanling calves infected by intranasal aerosol. Calves were monitored from days 1 to 5, and on day 6 (neonates) or 8 (weanlings) and, in a second trial at day 4.5, by histology, electron microscopy, immunocytochemistry and virus isolation. Mucosal lesions of neonates were similar to, but less extensive than, those of weanling calves. Loss of microvilli and goblet cells, with minimal epithelial erosions as early as day 1, progressed to necrosis of epithelium and adjacent lymphoid tissue, and leucocyte exudation. Lesions and clinical disease were progressive up to and including day 6 in neonates, but resolving in weanlings on days 5 and 8. By transmission electron microscopy, the physical characteristics of the phagocytic cells appeared similar in both age groups, and viral replication was not identified in leucocytes. Virus was isolated from, or found by immunocytochemistry in, the pharyngeal tonsil of all calves examined, except for two weanlings on days 1 and 8. Virus as detected by immunocytochemistry was restricted to epithelium and superficial lymphoid tissue in neonates, but was found in deep lymphoid tissue around germinal centres in weanlings. The study showed that the pharyngeal tonsil is readily infected with BHV-1 and may be an important lymphoid tissue for early anti-viral responses. The delayed inflammatory response and reduced viral clearance may contribute to the increased susceptibility of neonatal calves to fatal BHV-1 infections.

Adenoidectomy and otitis media

Adenoid enlargement has traditionally been considered a factor in otitis media; adenoid size, however, does not appear to be correlated with otitis media occurrence. Presence of pathogenic bacteria in the adenoids of children with otitis media has been shown, and adenoidectomy appears to affect the middle ear primarily by removal of the source of infection in the nasopharynx. Three recent randomized, controlled studies showed the efficacy of adenoidectomy in the treatment of chronic secretory otitis media. In one study comparing no treatment, adenoidectomy, and adenotonsillectomy, a significant benefit was seen with adenoidectomy that was not enhanced by tonsillectomy. Another study that compared adenoidectomy, tympanostomy tubes, and a combination of the two showed a significant reduction in effusion time and less surgical retreatment over 2 years in the two adenoidectomy groups. The third study demonstrated the effect of adenoidectomy in children with recurrent chronic otitis media with effusion after failure of tympanostomy tube insertion. All three studies showed that the effect of adenoidectomy was independent of adenoid size. This review discusses current concepts of adenoid physiology and pathology, the major adenoidectomy studies, and indications for the procedure.

Localization of rhinovirus replication in vitro with in situ hybridization

To facilitate understanding of human rhinovirus (HRV) pathogenesis, methods were developed for detection of HRV infection in vitro using in situ hybridization (ISH). HRV-14 RNA probes and oligonucleotide probes representing conserved sequences in the 5'-non-translated region were labeled with 35S and used to detect infected HeLa or WI-38 strain human embryonic lung cells in cytological preparations. ISH was shown to be specific for detection of HRV on a single-cell basis. Subsequently, in human nasal polyps infected in vitro, both oligonucleotide- and ribo-probes produced a strong signal in association with ciliated epithelial cells. In human adenoids infected in vitro, a signal was observed in non-ciliated epithelial cells. This study shows that HRV replicates in ciliated cells in the epithelium of human nasal polyps infected in vitro, and the presence of viral RNA in non-ciliated cells of the human adenoid infected in vitro suggests that other cell types may also support rhinovirus replication.

Iatrogenic influences on the heritability of childhood tonsillectomy: cohort differences in twin concordance

In 1980-82, a mailed questionnaire was completed by 3,810 pairs of adult twins enrolled on the Australian NH&MRC Twin Register. Twins were asked whether they had had their tonsils out and, if so, at what age. The sample was divided into four birth cohorts of approximately equal size, and only childhood tonsillectomy (to the age of 18) was considered. The prevalence of tonsillectomy differed markedly between cohorts, being highest in those born in the 1940s and early 1950s. Within each cohort, the prevalence was very similar in MZ and DZ twins, yet concordance was much higher in MZ twins, indicating the importance of genetic factors in predisposition to tonsillectomy. However, the proportions of variance in liability due to genetic and shared environmental factors differed markedly between cohorts. In the 1950s, when tonsillectomy was fashionable, shared environment accounted for 60% of variance and genetic factors for only 29%. However, by the early 1960s, when tonsillectomy was going out of fashion, heritability was up to 0.82 and shared environment accounted for only 10% of variance. Our results illustrate, once again, that heritability is not a constant, but depends on the precise characteristics of the population and the time at which it is studied.

Modern assessment of tonsils and adenoids

Modern assessment of the tonsils and adenoids is based on an appreciation of new concepts pertaining to the pathogenesis of tonsil and adenoid disease. Recognition of the emergence of beta-lactamase-producing and encapsulated anaerobic bacteria in the tonsils and adenoids should lead to a reconsideration of present therapeutic recommendations for antibiotic therapy in infectious tonsil and adenoid disease. The performance of a precise history, use of a standardized physical examination, and judicious use of laboratory evaluation are all necessary for appropriate patient management and improved communication between the pediatrician and otolaryngologist. Thus, appropriate recommendation for tonsillectomy and adenoidectomy will enhance their benefits, and the result will be happier and healthier children.