Ki-67, Bcl-2 and p53 expression in primary and metastatic melanoma

The aim of this study was to clarify the roles of the tumour proliferation marker Ki-67, the anti-apoptotic protein Bcl-2 and the cell cycle regulator p53 in primary cutaneous and metastatic melanoma. One hundred and seventeen primary melanomas and 18 metastatic tissue samples were analysed for immunohistochemical expression of Ki-67, Bcl-2 and p53. The staining results were correlated with disease progression and clinical outcome. The patient population comprised patients diagnosed with melanoma between 1988 and 1991. The clinical follow-up period for disease recurrence was 4.6 years (median; range, 0.2-7.5 years) and the follow-up period for overall survival was 10.0 years (median; range, 8.6-15.6 years). Ki-67 expression was not a prognostic factor in primary melanoma. High Bcl-2 expression was associated with such adverse prognostic factors as male gender, old age of the patient and tumour ulceration. High Bcl-2 expression was also associated with an adverse prognosis in intermediate-thickness (1.01-4.0 mm) melanomas (n=52) for disease-free (P=0.09) and overall (P=0.08) survival. In multivariate analysis, tumour thickness was the strongest prognostic factor for disease-free survival (P<0.01). High p53 expression indicated a poorer prognosis (P=0.05). In metastatic melanoma, the expression levels of Bcl-2 and p53 were lower than those in their primary counterparts (P=0.08 for each). Ki-67 expression showed no remarkable changes. It can be concluded that high p53 expression in tumour cells is associated with a poorer prognosis in primary melanoma, and high Bcl-2 expression in tumour cells is an adverse prognostic marker in intermediate-thickness primary melanoma.

Human primary adenotonsillar naïve phenotype CD45RA CD4 T lymphocytes undergo apoptosis upon stimulation with a high concentration of CD3 antibody

Young children need to develop immune tolerance to harmless foreign antigens such as digested nutrients and various inhaled airborne antigens. Because of its anatomical location, pharyngeal adenotonsillar tissue is a potential site for the establishment of this immune tolerance. To characterize possible mechanisms of peripheral immune tolerance, we studied human primary adenotonsillar naïve phenotype CD45RA(+) CD4(+) T cells, which represent cells that have not previously encountered foreign antigens. It was found that these CD45RA(+) CD4(+) T cells expressed higher levels of the activation marker CD69 as compared with peripheral blood CD45RA(+) CD4(+) T cells. Upon stimulation with a high concentration of CD3 antibody, which mimics the encounter of a high antigen dose, adenotonsillar CD45RA(+) CD4(+) T lymphocytes, but not peripheral blood CD45RA(+) CD4(+) T cells, underwent apoptosis. After 6 h stimulation with a high concentration of CD3 antibody, over 25% of the cells were apoptotic. Interfering with the Fas-FasL interaction with recombinant Fas or an antibody against Fas-ligand partially inhibited apoptosis. Our study results suggest that high concentrations of antigens, such as various nutrients and airborne antigens, may induce peripheral immune tolerance by selectively deleting naïve phenotype CD45RA(+) CD4(+) T cells via T-cell receptor-triggered apoptosis in human adenotonsillar tissue.

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.

Indium-111-bleomycin complex in squamous cell cancer xenograft tumors of nude mice

INTRODUCTION

Labeling of bleomycin with Auger-emitter Indium-111 increases cytotoxicity in squamous cell cancer (SCC) cell lines, as we have reported earlier. In this study, we investigated whether (111)In- BLMC is toxic and effective in vivo among SCC-xenografted mice. The influence of (111)InBLMC on the squamous cell carcinoma cell cycle stimulated interest.

MATERIALS AND METHODS

In an animal experiment, 10 SCC-xenografted mice were used, two for demonstrating targeting in gamma-camera images, eight for intraperitoneally receiving NaCl, BLM, or (111)InBLMC as therapy. After a 2-week follow-up, the tumors were analyzed for proliferation (mitoses, Ki-67). DNA flow cytometric analysis was carried out from tumor samples and three UT-SCC cell lines.

RESULTS

Tumors were observed on gamma-camera images in xenografted mice after a (111)InBLMC injection. The UT-SCC-19A-xenografted mouse had a T/non-T uptake of 7.54 at 4 hours after the injection. At the end of the therapeutic trial, the mice were alive. In spite of a small number of animals, our findings indicate that BLM and (111)InBLMC seem to be more effective than NaCl in reducing tumor size. The proliferative activity was strong in BLM and in (111)InBLMC groups, indicating regrowth of the tumors. In DNA analysis, the percentages of cells in the G2/M-phases increased after exposure to BLM and particularly to (111)InBLMC in all three cell lines.

CONCLUSIONS

The effect of BLM is preserved after the adding of Auger-emitter In-111. Tumor-seeking (111)InBLMC can be administered safely at tumor-decreasing concentrations in xenograft head and neck cancers. To demonstrate the antitumor effect of (111)InBLMC, the experiments should be extended to include a larger number of mice. BLM, and especially (111)InBLMC, seems to induce alteration in the cell cycle by producing a G2/M block. The verification of the result requires repeated in vitro experiments.

Analysis of risk factors for childhood persistent middle ear effusion

Although exposure to infectious agents and parental smoking are known to influence the overall risk of otitis media, these risk factors do not appear to be linked with the tendency to develop chronic otitis media with effusion (COME) instead of recurrent acute otitis media (RAOM). The genetic inflammatory response type of the child appears to influence the risk of persistent middle ear effusion in COME. Two different clinical presentations of childhood otitis media are encountered: RAOM; and COME, which is associated with persistent effusion in the middle ear. The objective of this study was to assess putative factors that may regulate the development of persistent middle ear effusion in COME. In total, 159 children with RAOM and their parents (n=304), and 55 children with COME and their parents (n=110) were evaluated. All the children with COME or RAOM were aged <4 years. There was no difference in the frequency of attendance at day care outside the home, number of siblings or parental smoking between children with RAOM and those with COME. The frequency of parental allergy and asthma was lower among children with COME than those with RAOM.

Adenoidectomy does not significantly reduce the incidence of otitis media in conjunction with the insertion of tympanostomy tubes in children who are younger than 4 years: a randomized trial

OBJECTIVE

To evaluate the efficacy of adenoidectomy in reducing the incidence of otitis media among children who are younger than 4 years and receive tympanostomy tubes.

METHODS

A randomized trial was conducted at a tertiary center clinic. A total of 217 children who were aged 12 to 48 months and had recurrent acute otitis media (>3 episodes during the past 6 months) or chronic otitis media with effusion, no obstructive symptoms as a result of adenoid enlargement, and no previous surgical intervention were enrolled in the study. Adenoidectomy in conjunction with the insertion of tympanostomy tubes or insertion of tympanostomy tubes without adenoidectomy was studied. The number of otitis media episodes during the follow-up period of 12 months was measured.

RESULTS

During the follow-up, the mean number of otitis media episodes was 1.7 among children who underwent adenoidectomy with concurrent insertion of tympanostomy tubes and 1.4 among children who received tympanostomy tubes only. The risk for recurrent otitis media (>or=3 episodes) could not be reduced by adenoidectomy (odds ratio: 1.66; 95% confidence interval: 0.80-3.46).

CONCLUSION

Adenoidectomy does not significantly reduce the incidence of acute otitis media in otitis prone children who are younger than 4 years and receive tympanostomy tubes.

A randomised public-health trial on automation-assisted screening for cervical cancer in Finland: performance with 470,000 invitations

Our objective was to evaluate automation-assisted screening, in comparison to the conventional method, in a routine population-based cervical cancer-screening programme. Our study is based on an individually randomised design involving approximately 160,000 invitees and 110,000 attendees every year. From 1999 to 2001, 471,297 women were invited to attend and 330,445 smears were screened (attendance rate 70.1%), of which 220,254 were tested conventionally and 110,191 were tested using the automation-assisted method. Cytologic Papanicolaou group II findings were reported slightly more often (RR = 1.04) in the automation-assisted method than in the conventional screening arm. There were 1,291 cases of histologically confirmed dysplasia or carcinoma (0.4% of the screened), one-third of which were severe dysplasia or a more severe finding (CIN3+). The detection rates of histologically verified findings were similar between the 2 screening arms. In Finland, the screening programme has been effective. As the detection rates, particularly of CIN3+, were similar between the screening arms, we will continue the automation-assisted method in the routine screening programme. Further follow-up for interval cancer incidence is required, however, to measure if the effect of screening is the same between the arms. A similar evaluation design is feasible to any other major or competing modification of the screening test or other element in the programme.

Induction of CD69 expression and Th1 cytokines release from human peripheral blood lymphocytes after in vitro stimulation with Alloiococcus otitidis and three middle ear pathogens

Alloiococcus otitidis is a recently discovered pathogen of otitis media. However, only a limited number of studies are available about the pathogenic and immunological role of A. otitidis. The aim of this study was to investigate the activation and the cytokine production of human peripheral blood lymphocytes at the early immune response after stimulation with A. otitidis. After stimulation of whole human peripheral blood lymphocytes for 18 h with whole killed A. otitidis or the three major middle ear pathogens (Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis), the expression of CD69 and the production of cytokines were analyzed. The expression of CD69 on T cells and B cells was dose-dependently enhanced after stimulation with A. otitidis. The release of interleukin (IL)-12 was induced after stimulation with A. otitidis, whereas the release of IL-4 was not induced after stimulation with A. otitidis. In addition, the release of interferon (IFN)-gamma was induced after stimulation with A. otitidis. Although the release of IFN-gamma started within 18 h after stimulation with A. otitidis, intracellular production of IFN-gamma was not observed in either CD4+ T cells or CD8+ T cells within 18 h upon stimulation. The patterns of CD69 expression and T helper-type 1 (Th1)-promoting cytokines production were similarly shown when human peripheral blood lymphocytes were stimulated with the other three major pathogens. Our results suggest that A. otitidis has sufficient immunogenic potential to modulate a host immune response, like the other three major middle ear pathogens, and also suggest that the immunogenicity of A. otitidis is very similar, at the early immune response, to that of the three major middle ear pathogens.

Platelet endothelial cell adhesion molecule-1 is expressed in adenoidal crypt epithelial cells

The adenoidal epithelial crypt is a potential site of antigen transport from pharyngeal lumen to adenoidal tissue. The base of the crypt is consistently infiltrated with leucocytes, forming a reticular lymphoepithelial structure. To evaluate mechanisms that possibly mediate leucocyte infiltration, expressions of leucocyte adhesion molecules, such as platelet endothelial cell adhesion molecule-1 (PECAM-1) (CD31), vascular cell adhesion molecule-1 (VCAM-1) (CD106) and intercellular adhesion molecule-1 (ICAM-1) (CD54), were studied in the adenoidal epithelial crypt. Epithelial cells in the outer opening of the adenoidal crypt were positive for VCAM-1, whereas epithelial cells at the base of the crypt were positive for PECAM-1. Isolated ICAM-1-expressing cells were found throughout the epithelial crypt. Double immunofluorescence staining revealed that the epithelial cells positive for PECAM-1 or VCAM-1 were positive for cytokeratin. The expression of PECAM-1 in the base and VCAM-1 at the orifice of the adenoidal epithelial crypt implies that the base and the orifice of the crypt have a distinct ability to recruit leucocytes. Epithelial cells expressing PECAM-1 may have a role in the formation of the reticular lymphoepithelial structure in the epithelial crypt.

Human in vivo-activated CD45R0(+) CD4(+) T cells are susceptible to spontaneous apoptosis that can be inhibited by the chemokine CXCL12 and IL-2, -6, -7, and -15

The number of T cells that have undergone proliferation after antigen stimulation in vivo must be controlled to prevent excessive accumulation of T cells, autoimmunity, and T cell neoplasia. We describe here that primary human adenotonsillar memory phenotype CD45R0(+) CD4(+) T cells, but not adenotonsillar naive-phenotype CD45RA(+) CD4(+) T cells, or peripheral blood naive or memory CD4(+) T cells, express high levels of activation-associated antigens CD38, CD69, CD71, and HLA-DR. These in vivo-activated CD45R0(+) CD4(+) T cells were susceptible to spontaneous and rapid apoptosis in vitro. Apoptosis could not be inhibited by the disruption of Fas-Fas ligand engagement or by the pan-caspase inhibitor ZVAD. Cross-linking of the T cell antigen receptor did not rescue cells from apoptosis. Apoptosis could be partially inhibited by the chemokine CXCL12/SDF-1, by IL-6, and by the IL-2 receptor common gamma chain-signaling cytokines IL-2, -7, and -15. Inhibitors of phosphatidylinositol 3-kinase accelerated apoptosis. We conclude that after in vivo activation of CD45R0(+) CD4(+) T cells, the cells experience a period of intrinsically elevated sensitivity to apoptosis and that multiple external signals control their survival.

Lymphoproliferative disease after allogeneic stem cell transplantation--pre-emptive diagnosis by quantification of Epstein-Barr virus DNA in serum

BACKGROUND

Lymphoproliferative disease (PTLD) is a life-threatening complication of organ transplantation. In matched, allogeneic, non-T-cell-depleted stem-cell transplantations (SCT) the disease develops early but has been thought to be rare.

OBJECTIVES

We determined by strict histopathological criteria the incidence of fatal Epstein-Barr-virus (EBV)-related PTLD in a large number of SCT, and assessed the diagnostic value of a real-time quantitative polymerase chain reaction (qPCR) for EBV-DNA in serum specimens.

STUDY DESIGN

Of the 257 SCT performed in Helsinki during 1994-1999, 132 (51%) recipients were alive and 125 (49%) had succumbed by June 2001. The necropsies were analyzed for EBV-related PTLD as evidenced by disseminated lymphocytic infiltrates labeled histochemically for antigens and RNA (EBER 1 and 2) detectable by in situ technology. From a subset of the PTLD cases (N=12) and a series of corresponding stem-cell recipient controls (N=36), consecutive samples of serum (N=103 and 364, respectively) were studied by qPCR for EBV-DNA, and the clinical data were reviewed.

RESULTS

The post-mortem analysis revealed 18 cases of PTLD (14% of the deceased), all of whom had received intensive immunosuppressive treatment including anti-thymocyte globulin for treatment or prophylaxis of graft versus host disease (GVHD). By using qPCR all the PTLD patients became EBV-DNA positive, in progressively rising copy numbers. EBV-DNA was first detectable 70 (median; range 24-154) days after SCT or 23 (4-86) days before death; i.e. earlier than the symptoms which appeared 15 (2-85) days before death. Among the SCT controls, EBV-DNA occurred sporadically (in only 3.9% sera).

CONCLUSIONS

qPCR for EBV-DNA in serum is a highly sensitive (100%) and specific (96%) diagnostic approach. Intensely immunosuppressed stem-cell recipients are at a great risk of developing PTLD, and should be carefully monitored for EBV-DNA, for pre-emptive treatment of this life-threatening disorder.

Adenoidectomy during early life and the risk of asthma

The objective of the study was to evaluate the risk of asthma in children who had undergone an adenoidectomy, an operation frequently performed on children with glue ear or recurrent otitis media. Two surveys were carried out, a nation-wide questionnaire returned by 483 individuals (survey A) and a survey of hospital discharge records involving 1616 children who had undergone an adenoidectomy and 161 control children who had undergone probing of the nasolacrimal duct due to congenital obstruction (survey B). The questionnaire (survey A) showed that an adenoidectomy before the age of 4 years was associated with asthma (OR 3.19, 95% CI 1.25; 8.13) and with allergy to animal dust (OR 2.50, 95% CI 1.27; 4.95). In survey B, asthma diagnosis was retrieved from the national asthma register. It showed also that adenoidectomy at an early age was associated with an increased risk of asthma (OR 6.74, 95% CI 2.99; 15.2). There was an association between asthma and adenoidectomy, even before adenoidectomy had actually been performed. The risk of asthma was highest among children who had had adenoidectomy because of recurrent otitis media. The observed association between an adenoidectomy and asthma may be explained by an underlying factor predisposing to both recurrent otitis media and asthma.

High incidence of PTLD after non-T-cell-depleted allogeneic haematopoietic stem cell transplantation as a consequence of intensive immunosuppressive treatment

The occurrence of post-transplant lymphoproliferative disorder (PTLD) in relation to immunosuppressive treatment was determined in 257 patients treated with non-T-cell-depleted allogeneic stem cell transplantation from an HLA-matched sibling (173 patients) or unrelated donor (84 patients). The conditioning consisted of total body irradiation and cyclophosphamide (myeloablative conditioning, 250 patients), or fludarabine combined with cyclophosphamide or a single 2 Gy dose of TBI (nonmyeloablative conditioning, seven patients). In transplantations from an unrelated donor, the patients also received antithymocyte globulin (ATG). The prophylaxis against graft-versus-host disease (GVHD) consisted of cyclosporine A, methotrexate, and methylprednisolone. The autopsy reports of deceased patients were systematically reviewed, and the autopsy materials of cases suggestive of PTLD were re-examined histologically for Epstein-Barr virus (EBV). Nineteen patients with EBV-positive PTLD were identified, of whom six had been transplanted from a sibling donor and 13 from an unrelated donor. All the patients who developed PTLD had been given ATG either for the treatment of steroid-resistant acute GVHD (all PTLD patients with a sibling donor and one with an unrelated donor), or as part of the conditioning (all patients with an unrelated donor). In conclusion, in transplantations from an HLA-identical donor with a non-T-cell-depleted graft, the risk of PTLD correlated strongly with the intensity of the immunosuppressive treatment.

Prospective and randomised public-health trial on neural network-assisted screening for cervical cancer in Finland: results of the first year

Our objective was to evaluate the feasibility and relative validity of interactive neural network assisted screening (Papnet) in primary mass screening for cervical cancer as a public health policy (routine screening). A randomized, ongoing trial involved 152,969 invitees and 108,686 attendees in the organized mass screening in Finland in 1999. Drawing invitations from the population registry, women were randomized 2:1 at an individual level to have their smear analyzed either conventionally or with Papnet. The distribution of smears to different cytological categories, detection rates of dysplasias, in situ carcinomas and cancers were estimated with smears analyzed either conventionally (72,461) or by Papnet (36,225). A total of 108,686 smears were screened and 449 were histologically confirmed as dysplasias and carcinomas. The detection rates for histologically verified carcinoma in situ/severe dysplasia, moderate and mild dysplasias were 0.14%, 0.14% and 0.13% with conventional and 0.14%, 0.14% and 0.11% with Papnet, respectively. The detection rate of invasive cancer was 0.06 per thousand (n = 4) with conventional method and 0.08 per thousand (n = 3) with Papnet. None of the differences were statistically significant (p > 0.05). Papnet was able to identify 92.5% of healthy women (normal cytology), and the specificity of conventional smear was 92.9%. The positive predictive value (Pap Classes III-V) of Papnet was slightly but not significantly better (55% vs. 51%). Papnet screening was feasible as a part of routine screening and performed equally well compared to conventional one methods used in Finland. Organized mass screening was practiced very successfully in the last 38 years. We are going to continue the trial to study the potential trends in cervical cancer incidence in both study arms.

Quality improvement project in cervical cancer screening: practical measures for monitoring laboratory performance

BACKGROUND

We conducted a quality improvement project in a cervical cancer screening programme in Helsinki in order to see if detection of precancerous lesions could be influenced by external (participation rate) and internal (laboratory praxis) quality measures.

METHODS

In order to increase the participation rate, a second personal invitation to Pap-test was mailed to nonparticipants of the first call. In order to improve the quality of screening, the cytotechnicians monitored their performance longitudinally by recording the number of slides reviewed per day, the pick-up rate of abnormal smears, the report of the consulting cytopathologist, and the number of histologically verified lesions detected from the cases that they had screened. Regular sessions were held to compare the histological findings with the cytological findings of all cases referred for colposcopy. No pressure was applied on the cytotechnicians to ensure that they felt comfortable with their daily workload.

RESULTS

A total of 110 000 smears were screened for cervical cancer at the Helsinki City Hospital during 1996-99. Initially, the overall participation rate increased from 62% to 71%. The number of histologically confirmed precancerous lesions (CIN 1-3) more than doubled and their detection rate increased from 0.32% to 0.72%.

CONCLUSIONS

Continuous education and feedback from daily work performance were important, yet rather inexpensive means in increasing laboratory performance. Additional measures are needed to further increase the participation rate. Impact of the quality measures on cancer incidence needs to be assessed later on.

Effect of type of screening laboratory on population-based occurrence of cervical lesions in Finland

The incidence of cervical cancer decreased in Finland over a 30-year period because of an effective screening program, but in the beginning of the 1990s it began to increase. Reasons for such an increase are variable: changes in sexual habits, shortcomings in attendance for screening and possibly variation in laboratory quality. We evaluated the impact of 3 laboratories in the greater Helsinki area on screening performance and on the incidence of invasive cervical cancer and preinvasive cervical lesions in the target population. We studied time trends, geographic differences in attendance and detection rates from screening and the incidence of invasive cancer in the greater Helsinki area (population about 1 million) during the 1990s, when screening was reorganized from the Cancer Society of Finland laboratory to the municipal one (Helsinki) and to a private laboratory (Espoo), while in Vantaa screening remained with the same Cancer Society laboratory. The attendance rate for screening increased during the study period in all 3 cities. The numbers of cytologically suspected and histologically confirmed precancerous lesions found, including severe lesions, decreased significantly with the change of laboratory in Espoo; but in Helsinki and Vantaa, they increased. The overall incidence of invasive cervical cancer increased in all cities in the age groups screened but mostly in Espoo. The rather rapid changes and variation in trends in the number of screening findings cannot be explained by changes in etiologic factors or attendance. They may be related more to the quality of the laboratory performance and perhaps to the criteria used in cytology and colposcopy. A well-organized auditing system is proposed to maintain high quality in screening.

Predisposition to atopic symptoms to inhaled antigens may protect from childhood type 1 diabetes

OBJECTIVE

To assess the inverse association between type 1 diabetes and asthma to establish whether environmental and/or genetic factors predisposing to asthma or to atopic symptoms to inhaled antigens protect from diabetes. RESEACH DESIGN AND METHODS: Questionnaires were returned by 306 probands with childhood type 1 diabetes, their 506 nonaffected siblings, and 406 age- and sex-matched unaffected population control subjects. The main outcome measures were self-reported physician-diagnosed asthma and atopic symptoms to animal dust and pollen.

RESULTS

Risk of diabetes was inversely associated with asthma (odds ratio 0.49 [95% CI 0.24-1.00]), allergy to animal dust (0.67 [0.45-0.99]), and to a lesser degree to pollen (0.74 [0.51-1.07]) when the probands were compared with the population control subjects. Among the children of the families of an affected proband, the risk of diabetes appeared to be inversely associated with asthma (0.54 [0.27-1.09]) but not with allergy to animal dust (0.99 [0.66-1.47]) nor allergy to pollen (0.88 [0.62-1.27]).

CONCLUSIONS

The frequency of asthma and atopic symptoms to some inhaled antigens is decreased in individuals with childhood type 1 diabetes. Factors predisposing to atopic symptoms to inhaled antigens may protect from childhood type 1 diabetes.

Malignancies after heart transplantation: presence of Epstein-Barr virus and cytomegalovirus

The presence of Epstein-Barr virus (EBV), human papilloma virus (HPV), and cytomegalovirus (CMV) was studied in 20 patients who developed malignancies after heart transplantation in the Helsinki University Central Hospital. The tumors were analyzed for the presence of HPV by polymerase chain reaction and for EBV by in situ hybridization. Clinical CMV infection was verified by immunochemical quantitation of CMV antigen in peripheral blood cells. HPV was detected in one of the eight epithelial malignant tumors studied. Three of the six lymphomas were positive for EBV. Two (67%) of 3 patients with EBV-positive lymphomas and one (33%) of the other three lymphomas but only 2 (14%) of 14 patients who developed other malignancies had a history of a manifest post-transplantation CMV infection prior to the development of malignancy. These results confirm the presence of EBV in lymphomas of heart transplant recipients and suggest that CMV might have a contributory role in the development of EBV-associated lymphomas.

Otitis media as a sign of Wegener's granulomatosis in childhood

Wegener's granulomatosis (WG) is a rare disease among paediatric patients. Chronic otitis media with or without facial nerve dysfunction is a known manifestation of the disease among adults. A case of a 15-year-old boy with WG, whose initial symptoms were acute otitis media and facial nerve paralysis, is presented. The otorhinolaryngological manifestations, as well as diagnostic and current treatment modalities in paediatric patients with WG, are discussed.

Causes of tonsillar disease and frequency of tonsillectomy operations

OBJECTIVE

To characterize the factors that influence the frequency of tonsillectomy and adenoidectomy operations.

DESIGN AND SETTING

Nationwide questionnaire. Analysis of patients undergoing tonsillectomy or adenoidectomy at Helsinki University Central Hospital, Helsinki, Finland.

PARTICIPANTS

Four hundred eighty-three of 819 individuals randomly selected from the Finnish National Public Registry. Two thousand two hundred thirty-one individuals younger than 30 years who underwent tonsillectomy (888 patients), adenotonsillectomy (294 patients), or adenoidectomy (1049 patients) at Helsinki University Central Hospital from January 1, 1997, through December 31, 1998.

MAIN OUTCOME MEASURES

Age of the individual at the time of operation. Indication for the operation.

RESULTS

The frequency of adenoidectomies was 24% (116 persons) and that of tonsillectomies 8% (39 persons) among the 483 individuals who returned the questionnaire. The frequency of tonsillectomy operations by age was multimodal; the frequency of tonsillectomies increased in preschool-aged children, declined thereafter, and increased again in teenagers. Tonsillar hyperplasia was the most frequent among children younger than 10 years, peritonsillar abscesses among teenagers, and chronic tonsillitis among individuals older than 20 years. The proportion of females was higher than males among teenaged patients. However, the cause and sex distribution could not explain the multimodality in the age-specific frequency. The age-specific frequency of tonsillectomies performed because of peritonsillar abscesses still followed a multimodal distribution.

CONCLUSIONS

Factors relating to respiratory tract infections, maturation of the immune system, and the onset of puberty contribute to the cause of tonsillar disease. Distinct indications for tonsillectomy should be defined for preschool-aged children, teenagers, and individuals older than 20 years.

Stimulation of adenoidal lymphocytes by Alloiococcus otitidis

Otitis media with effusion (OME) is characterized by persistent effusion in the middle ear cavity and by chronic inflammation in the middle ear mucosa. Alloiococcus otitidis, a gram-positive aerobic bacterium, has been isolated in middle ear effusion, and by means of sensitive polymerase chain reaction detection assays it has been detected in as many as 20% of middle ear aspirates of patients with OME. Because A otitidis may freely interact with leukocytes in the middle ear effusion, it may potentially modulate the inflammatory reaction in OME. To study the nature of these interactions, we applied an in vitro assay in which killed A otitidis bacteria were incubated with peripheral blood and adenoidal mononuclear cells. The expression of the proliferation-associated surface marker CD69 was then measured in B lymphocytes and in CD4+ helper and CD8+ cytotoxic-suppressor T lymphocytes by means of multicolor flow cytometry. Alloiococcus otitidis induced the expression of CD69 in both peripheral blood and adenoidal T and B cells. Among the T cells, the cytotoxic-suppressor T lymphocytes were preferentially activated. It was also tested whether A otitidis would have an effect in another cytotoxic and immunoregulatory system, namely, the induction of natural killer cell activity in peripheral blood mononuclear cells. However, the effect was minimal compared with that of Salmonella minnesota or Staphylococcus aureus. The results show that A otitidis has a unique immunostimulatory capacity in vitro that is mainly confined to CD8+ T lymphocytes.