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.

Effect of Alloiococcus otitidis and three pathogens of otitis media in production of interleukin-12 by human monocyte cell line

Alloiococcus otitidis is detected in middle ear effusion of otitis media with effusion (OME). Only a limited number of studies are available concerning the immunological profile of A. otitidis. We have studied the ability of A. otitidis and three other representative pathogens of otitis media to stimulate the production of interleukin-12 (IL-12) from a monocytic cell line THP-1. Viable A. otitidis induced the production of IL-12 in THP-1 cells but IL-12 production was reduced if glutaraldehyde-fixed bacteria were used as stimulants. When viable bacteria were physically separated from THP-1 cells during the stimulation period, remarkable reductions of IL-12 secretion were shown after challenge with gram-positive bacteria A. otitidis and S. pneumoniae. When stimulated with soluble extracts of A. otitidis, THP-1 secreted IL-12 in a dose-dependent manner. The subfraction with a molecular mass over 100 kDa showed a strong ability to induce IL-12 production. Our results show that A. otitidis has immunostimulatory capacity with regard to IL-12 production. We also show that soluble antigen(s) of A. otitidis can modulate the immune response in OME.

Adenoids provide a microenvironment for the generation of CD4(+), CD45RO(+), L-selectin(-), CXCR4(+), CCR5(+) T lymphocytes, a lymphocyte phenotype found in the middle ear effusion

Adenoidectomy in children with otitis media with effusion reduces inflammation in the middle ear by an unknown mechanism. Potentially, the adenoids of these children may serve as a site for the differentiation of lymphocytes, which after entering blood circulation eventually extravasate in the middle ear mucosa and thereby contribute to excessive inflammation. During lymphocyte extravasation various adhesion molecules and chemokines play a crucial role. To evaluate possible connections between the adenoids and middle ear inflammation, the expression of the chemokine receptors CXCR4 and CCR5 and the lymphocyte homing receptor L-selectin were analyzed in adenoidal and middle ear lymphocytes. It was found that most CD4(+) T lymphocytes in the middle ear effusion express the memory phenotype marker CD45RO and the chemokine receptors CXCR4 and CCR5, but are negative for the lymphocyte homing receptor L-selectin. This cell phenotype was rare in peripheral blood but was found much more frequently in the adenoids. The results suggest that the adenoids provide a microenvironment for the generation for CD4(+), CD45RO(+), L-selectin(-), CXCR4(+) and CCR5(+) T lymphocytes. Further, these cells may include cells that have the capacity to home to the middle ear mucosa. As the adenoidal CD4(+) memory phenotype CD45RO(+) T cells expressed the activation antigen CD69 and included cells expressing the HIV co-receptors CXCR4 and CCR5 at a high level, they may be permissive for HIV infection.

Thoracic duct cyst: a case report and review of 29 cases

Cysts of the thoracic duct are rare. We report a case of a cervical thoracic duct cyst and review 29 thoracic duct cysts reported previously (19 mediastinal, 9 cervical, and 1 abdominal). The mean age of the patients was 47.6 years (range 17 to 86 years). Fourteen (46.7%) of the patients were asymptomatic. When symptoms were present, they ranged from retrosternal pain, dysphagia, and dyspnea to respiratory insufficiency and superior vena cava compression. Diagnosis of the cyst can be made after computed tomography or ultrasonography. The cystic fluid contains T lymphocytes and triglycerides in excess. The symptoms in a patient with a thoracic duct cyst are related to compression of adjacent structures. The most profound symptoms are likely to be produced by mediastinal cysts above the aortic arch. Treatment consists of surgical removal of the cyst and ligation of all lymphatics connected to the cyst.

Differentiation of T lymphocytes in the human adenoid as measured by the expression of CD45 isoforms

Encounter of antigen by T lymphocyte on antigen-presenting cells results in changes in the expression of several cell surface molecules, including the abundant cell surface glycoprotein CD45. We have characterized the expression of the CD45 isoforms CD45RA and CD45RO in CD4+ and CD8+ T lymphocytes in the adenoids and peripheral blood of young children. We found that the relative proportions of CD45RA-,CD45RO+ antigen-experienced T cells was higher in the adenoids than in peripheral blood, and that the proportion of naive or resting CD45RA+,CD45RO- T cells was lower in the adenoids than in peripheral blood. The frequency of bright double-positive CD45RA+,CD45RO+ T cells, which represent cells in transition from the CD45RA+ to CD45RO+ phenotype, was higher in the adenoids than in peripheral blood. The frequency of another double-positive cell population, but with unknown ontogeny, expressing both CD45RA and CD45RO at a low level, was higher in peripheral blood than in adenoidal T cells. It was found that the frequency of adenoidal antigen-experienced CD45RA-,CD45RO+ T lymphocytes increased with increasing age of the child. These results are consistent with the model that the adenoids serve as a site for conversion of CD45RA+ to CD45RO+ T lymphocytes, and that the maturation of the immune system in young children is associated with phenotypic changes in T lymphocytes residing in secondary lymphoid organs.

Age-associated changes in the cellular composition of the human adenoid

Histological investigations suggest that the size and number of lymphoid follicles of the adenoids and tonsils decrease during ageing. The mechanisms underlying the histological changes are unknown. The authors have analysed the frequency of lymphocyte subpopulations in the adenoids by flow cytometry. The proportion of B lymphocytes decreased and the proportion of T lymphocytes of all mononuclear cells increased with age. Of all B lymphocytes the proportion of CD38+, surface IgD- B lymphocytes representing the germinal centre cell phenotype, decreased and the proportion of CD38-, IgD- B lymphocytes representing the mature B lymphocyte phenotype, increased with age. The expression of CD23, a cell surface molecule associated with activation of follicular mantle IgD+ B lymphocytes, did not change with increasing age. The results imply that the involution of the adenoid is associated with a decreased germinal centre reaction and relative accumulation of mature B cells in the adenoidal tissue, as analysed by three-colour flow cytometry.

Function of lymphocyte homing-associated adhesion molecules on human natural killer and lymphokine-activated killer cells

We have analyzed the ability of fresh and rIL-2-activated human NK cells to interact with high endothelial venules (HEV) that are known to support physiologic lymphocyte extravasation, and examined the role of different adhesion molecules in this process. In in vitro HEV-binding assays, NK cells bound to both peripheral lymph node (pLN) and mucosal HEV. Activation by rIL-2 slightly decreased adherence to pLN HEV, but increased adherence to mucosal high endothelium. Markedly fewer NK cells than PBL expressed L-selectin, and the expression was diminished further upon treatment with rIL-2. Inhibition studies showed, however, that L-selectin was the most important single molecule to mediate adhesion to pLN HEV. Binding to mucosal HEV was mediated mainly by CD44 and alpha 4 integrin, and the expression level of these molecules was increased by rIL-2, paralleling the results in HEV-binding assays. Higher m.w. forms of CD44, representing differentially glycosylated/variant forms of CD44, were more abundant on large granular lymphocytes than on unseparated PBL. We conclude that, despite weak recirculatory capacity, NK cells or a subpopulation of NK cells with the correct adhesion molecules can interact with and bind to high endothelial cells. Lymphokines can modulate the expression of adhesion molecules that NK cells utilize for HEV binding. Our results suggest that activation of NK cells with IL-2 may facilitate the extravasation of lymphokine-activated killer cells, especially to mucosal sites, whereas homing to peripheral lymphoid tissues may be diminished. This should be taken into consideration when procedures for lymphokine-activated killer cell immunotherapy are planned.

Function of lymphocyte homing-associated adhesion molecules on human natural killer and lymphokine-activated killer cells

We have analyzed the ability of fresh and rIL-2-activated human NK cells to interact with high endothelial venules (HEV) that are known to support physiologic lymphocyte extravasation, and examined the role of different adhesion molecules in this process. In in vitro HEV-binding assays, NK cells bound to both peripheral lymph node (pLN) and mucosal HEV. Activation by rIL-2 slightly decreased adherence to pLN HEV, but increased adherence to mucosal high endothelium. Markedly fewer NK cells than PBL expressed L-selectin, and the expression was diminished further upon treatment with rIL-2. Inhibition studies showed, however, that L-selectin was the most important single molecule to mediate adhesion to pLN HEV. Binding to mucosal HEV was mediated mainly by CD44 and alpha 4 integrin, and the expression level of these molecules was increased by rIL-2, paralleling the results in HEV-binding assays. Higher m.w. forms of CD44, representing differentially glycosylated/variant forms of CD44, were more abundant on large granular lymphocytes than on unseparated PBL. We conclude that, despite weak recirculatory capacity, NK cells or a subpopulation of NK cells with the correct adhesion molecules can interact with and bind to high endothelial cells. Lymphokines can modulate the expression of adhesion molecules that NK cells utilize for HEV binding. Our results suggest that activation of NK cells with IL-2 may facilitate the extravasation of lymphokine-activated killer cells, especially to mucosal sites, whereas homing to peripheral lymphoid tissues may be diminished. This should be taken into consideration when procedures for lymphokine-activated killer cell immunotherapy are planned.

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.

Peripheral gamma delta T cell receptor-bearing lymphocytes are increased in children with celiac disease

The percentages of gamma delta T cell receptor-bearing (TCR+) cells in the peripheral blood and jejunal mucosa of patients with celiac disease were measured before treatment, during a gluten free-diet, and after a gluten challenge. The percentages of the different cell types were evaluated by flow cytometry, and immunohistochemical staining of the jejunal specimen was used to identify lymphocyte surface markers. Nineteen blood samples and intestinal specimens from 13 children with celiac disease (eight samples taken before treatment, six during gluten-free diet, and five after gluten challenge) and samples from nine controls were studied. The proportion of gamma delta TCR+ lymphocytes was significantly higher both in the peripheral blood and the jejunal mucosa of the patients with celiac disease. A significant correlation was found between the percentage of peripheral gamma delta TCR+ cells and the density of gamma delta TCR+ cells in the lamina propria.

Contact of lymphocytes with Helicobacter pylori augments natural killer cell activity and induces production of gamma interferon

We studied the capacity of glutaraldehyde-fixed Helicobacter pylori to stimulate natural killer (NK) cell activity. Bacteria were incubated overnight with peripheral blood lymphocytes enriched for large granular lymphocytes (LGL), the mediators of non-major histocompatibility complex-restricted cellular cytotoxicity. Then, the cytolytic activity of LGL was tested against various tumor target cells. We observed that efficient cytolytic activity was generated against resistant and nonresistant tumor target cell lines. Nine local clinical isolates of H. pylori and the reference strain NCTC 11637 were tested, and they all were equally effective in inducing NK cell activity. However, flagellin antigen, glycine extract, urease, and lipopolysaccharide prepared from H. pylori NCTC 11637 all failed to induce significant NK cell activity. The supernatants which were collected after coincubation of bacteria with LGL contained a factor(s) which could activate resting LGL into efficient cytolytic activity. The supernatants were also analyzed for interferon (IFN) activity. We observed that high titers of IFN were produced and that IFN activity was neutralized with anti-gamma interferon (IFN-gamma) antiserum, but not with anti-IFN-alpha antiserum. Thus, contact of lymphocytes with H. pylori leads to efficient stimulation of NK cell activity and the production of IFN-gamma.

Involvement of beta 2-integrins in the migration of human natural killer cells

Human large granular lymphocytes with the NK cell phenotype (CD16+ or CD56+CD3-) were greatly enriched among the cells which migrated spontaneously through untreated or albumin-coated, 3-microns pore size polycarbonate filters for 1 to 8 h. Three days of rIL-2 treatment (300 IU/ml) and 3 to 5 wk of rIL-2 treatment (100 IU/ml) generated a 2.7 +/- 0.9-fold and 5.6 +/- 0.8-fold increase in cell migration, respectively. The adhesion and subsequent migration of freshly isolated NK cells was mainly mediated by CD11b/CD18, because migration could be inhibited by 80 +/- 8% anti-CD11b (Mac-1) antibodies but not with antibodies against CD11a (LFA-1) or CD11c (p150,95), the other alpha-chains of the beta 2-integrins. After rIL-2 activation, however, CD11a/CD18 was the major receptor utilized in migration, inasmuch as anti-CD11a antibody caused a 69 +/- 8% reduction in the number of migrated cells. Anti-CD11b antibody decreased migration by 43 +/- 12%, and together these antibodies inhibited migration by 82 +/- 7%. Anti-CD11a alone did not have any effect on adhesion, but CD11a/CD18 cooperated in the adhesion because anti-CD11b decreased adhesion by 40 +/- 11% and together these antibodies inhibited adhesion by 74 +/- 6%. The ability of large granular lymphocytes to rapidly utilize beta 2-integrins and unidentified ubiquitous ligands for binding and migration may be significant for their capacity to function in the first line of immune defense under highly variable conditions.

Involvement of beta 2-integrins in the migration of human natural killer cells

Human large granular lymphocytes with the NK cell phenotype (CD16+ or CD56+CD3-) were greatly enriched among the cells which migrated spontaneously through untreated or albumin-coated, 3-microns pore size polycarbonate filters for 1 to 8 h. Three days of rIL-2 treatment (300 IU/ml) and 3 to 5 wk of rIL-2 treatment (100 IU/ml) generated a 2.7 +/- 0.9-fold and 5.6 +/- 0.8-fold increase in cell migration, respectively. The adhesion and subsequent migration of freshly isolated NK cells was mainly mediated by CD11b/CD18, because migration could be inhibited by 80 +/- 8% anti-CD11b (Mac-1) antibodies but not with antibodies against CD11a (LFA-1) or CD11c (p150,95), the other alpha-chains of the beta 2-integrins. After rIL-2 activation, however, CD11a/CD18 was the major receptor utilized in migration, inasmuch as anti-CD11a antibody caused a 69 +/- 8% reduction in the number of migrated cells. Anti-CD11b antibody decreased migration by 43 +/- 12%, and together these antibodies inhibited migration by 82 +/- 7%. Anti-CD11a alone did not have any effect on adhesion, but CD11a/CD18 cooperated in the adhesion because anti-CD11b decreased adhesion by 40 +/- 11% and together these antibodies inhibited adhesion by 74 +/- 6%. The ability of large granular lymphocytes to rapidly utilize beta 2-integrins and unidentified ubiquitous ligands for binding and migration may be significant for their capacity to function in the first line of immune defense under highly variable conditions.

Migration of recombinant IL-2-activated T and natural killer cells in the intercellular space of human H-2 glioma spheroids in vitro. A study on adhesion molecules involved

The migration of rIL-2-activated T and NK cells into the intercellular space of glioma tissue was studied using multicellular spheroids grown from the human H-2 glioblastoma cell line as targets. Lymphocytes of all analyzed subtypes migrated into the spheroids, but CD56+ cells were particularly migratory. Lymphocytes and the H-2 tissue expressed adhesion molecule subunits for the following potential cell-cell or cell-matrix interactions: alpha 3 beta 1 (VLA-3) to fibronectin, laminin, and collagen; alpha 4 beta 1 (VLA-4) and alpha 5 beta 1 (VLA-5) to fibronectin; alpha 6 beta 1 (VLA-6) to laminin; alpha 4 beta 1 to VCAM-1; alpha L beta 2 (Leu-CAMa/LFA-1) to CD54 (ICAM-1); CD44 to fibronectin, collagen, laminin, hyaluronate; CD2 to CD58 (LFA-3); and CD56 (N-CAM) to CD56. In the H-2 tissue, CD54 and VCAM-1 were expressed as a gradient. The expression of CD54 was weak in the peripheral zone and the expression was stronger in the quiescent deeper zone, whereas the distribution of VCAM-1 showed an inversed pattern. The low expression of CD54 was up-regulated along the frontier of migrating lymphocytes. The migration was almost totally prevented by the anti-CD18 (beta 2) mAb IB4 and TS1/18, and also strongly inhibited by the anti-CD54 mAb LB-2. Instead, mAb known to inhibit the binding of beta 1 integrins to fibronectin were not significantly inhibitory. However, a combination of the GPEILDVPST and GRGDS peptides, which compete for the binding of alpha 4 beta 1 and alpha 5 beta 1 to fibronectin and may also affect other adhesion systems, partially prevented migration.

Migration of recombinant IL-2-activated T and natural killer cells in the intercellular space of human H-2 glioma spheroids in vitro. A study on adhesion molecules involved

The migration of rIL-2-activated T and NK cells into the intercellular space of glioma tissue was studied using multicellular spheroids grown from the human H-2 glioblastoma cell line as targets. Lymphocytes of all analyzed subtypes migrated into the spheroids, but CD56+ cells were particularly migratory. Lymphocytes and the H-2 tissue expressed adhesion molecule subunits for the following potential cell-cell or cell-matrix interactions: alpha 3 beta 1 (VLA-3) to fibronectin, laminin, and collagen; alpha 4 beta 1 (VLA-4) and alpha 5 beta 1 (VLA-5) to fibronectin; alpha 6 beta 1 (VLA-6) to laminin; alpha 4 beta 1 to VCAM-1; alpha L beta 2 (Leu-CAMa/LFA-1) to CD54 (ICAM-1); CD44 to fibronectin, collagen, laminin, hyaluronate; CD2 to CD58 (LFA-3); and CD56 (N-CAM) to CD56. In the H-2 tissue, CD54 and VCAM-1 were expressed as a gradient. The expression of CD54 was weak in the peripheral zone and the expression was stronger in the quiescent deeper zone, whereas the distribution of VCAM-1 showed an inversed pattern. The low expression of CD54 was up-regulated along the frontier of migrating lymphocytes. The migration was almost totally prevented by the anti-CD18 (beta 2) mAb IB4 and TS1/18, and also strongly inhibited by the anti-CD54 mAb LB-2. Instead, mAb known to inhibit the binding of beta 1 integrins to fibronectin were not significantly inhibitory. However, a combination of the GPEILDVPST and GRGDS peptides, which compete for the binding of alpha 4 beta 1 and alpha 5 beta 1 to fibronectin and may also affect other adhesion systems, partially prevented migration.

Potentiation of human natural killer cell cytotoxicity by Salmonella bacteria is an interferon- and interleukin-2-independent process that utilizes CD2 and CD18 structures in the effector phase

Incubation of large granular lymphocytes (LGL) with glutaraldehyde-fixed bacteria stimulated in the supernatant the production of interferon (IFN), which proved to be mainly IFN-gamma. Even though IFN-gamma was produced upon exposure of LGL to bacteria, anti-IFN-gamma antibodies failed to interfere with induction of cytotoxicity by bacterial contact. Anti-IFN-gamma receptor antibodies had no effect on the induction of activated killing by bacterial contact either. We also tested the effect of anti-IFN-alpha antibody, but it failed to interfere with induction of cytotoxicity by bacterial contact. No interleukin-2 (IL-2) was detected in the culture supernatant of bacterially activated LGL by the mouse HT2 cell assay, nor did we detect any IL-2 mRNA in bacterially activated LGL by Northern RNA blot assay. Neutralizing anti-IL-2 antiserum had no effect on the induction of activated killing by bacterial contact, and recombinant IL-4 did not interfere with the induction of activated killing. We then studied the membrane structures involved in bacterially activated killing. Anti-CD18 monoclonal antibody did not interfere with the induction phase of bacterially activated killing. However, both anti-CD18 and anti-CD2 antibodies inhibited the effector phase of bacterially activated killing. The effector pathways utilized by activated LGL depended on the mode of activation in that even though bacterially activated LGL were sometimes blocked by anti-CD2 monoclonal antibody, recombinant-IL-2-stimulated LGL were not. In conclusion, our present results suggest that there may be mediators other than exogenously secreted IFNs and IL-2 which are responsible for the induction of activated killing after bacterial contact. CD18 and CD2 structures were shown to be involved in the effector phase of bacterially activated killing.

Bacterial activation of human natural killer cells. Characteristics of the activation process and identification of the effector cell

We showed previously that contact of human peripheral blood lymphocytes with glutaraldehyde-fixed Salmonella bacteria augmented their cytotoxic capacity against NK-sensitive targets. We have now analyzed the characteristics of the activation and also identified the subsets of lymphocytes responding to bacterial contact. Blocking of protein synthesis with cyclohexamide totally abrogated bacterial induction of activated killing (AK), whereas inhibition of DNA synthesis with mitomycin C did not significantly affect the capacity of lymphocytes to respond to bacterial contact. Both the induction and the effector phase of AK were radioresistant. The AK cells exhibited efficient lytic activity, comparable to that induced by recombinant IL 2 (rIL 2), against NK-resistant targets (including both hematopoietic and solid tumor cell lines). All inducible cytotoxic activity was contained within the subset of lymphocytes expressing Leu-19 (NKH-1) antigen. Leu-19- lymphocytes exhibited no significant NK activity and could not be further stimulated by bacterial contact, rIL 2, or IFN-alpha. Within the Leu-19+ lymphocyte subset, two distinct cell types were present; CD3-, Leu-19+ NK cells and CD3+. Leu-19+ T cells. The CD3+, Leu-19+, T cells mediated low levels of non-MHC-restricted cytotoxicity against K562, but did not respond to bacterial contact, even though rIL 2 could augment their lytic activity slightly. However, the cytotoxic activity of CD3-, Leu-19+ NK cells was significantly augmented by bacterial contact. Within the CD3-, Leu-19+ NK cell population both CD16+ and CD16- cells responded to bacterial activation. The CD3-, CD16-, Leu-19+ cells constituted 1 to 4% of the Percoll-fractionated low buoyant density lymphocytes and accounted for the activation seen within the CD16- lymphocyte population. Thus bacterial stimulation of NK activity seems to be mediated for the most part via CD16+, Leu-19+ cells, and a minor overall contribution is mediated via CD3-, CD16-, Leu-19+ cells. No apparent involvement of T cells was seen in the lytic response of lymphocytes to bacterial contact.

Bacterial activation of human natural killer cells. Characteristics of the activation process and identification of the effector cell

We showed previously that contact of human peripheral blood lymphocytes with glutaraldehyde-fixed Salmonella bacteria augmented their cytotoxic capacity against NK-sensitive targets. We have now analyzed the characteristics of the activation and also identified the subsets of lymphocytes responding to bacterial contact. Blocking of protein synthesis with cyclohexamide totally abrogated bacterial induction of activated killing (AK), whereas inhibition of DNA synthesis with mitomycin C did not significantly affect the capacity of lymphocytes to respond to bacterial contact. Both the induction and the effector phase of AK were radioresistant. The AK cells exhibited efficient lytic activity, comparable to that induced by recombinant IL 2 (rIL 2), against NK-resistant targets (including both hematopoietic and solid tumor cell lines). All inducible cytotoxic activity was contained within the subset of lymphocytes expressing Leu-19 (NKH-1) antigen. Leu-19- lymphocytes exhibited no significant NK activity and could not be further stimulated by bacterial contact, rIL 2, or IFN-alpha. Within the Leu-19+ lymphocyte subset, two distinct cell types were present; CD3-, Leu-19+ NK cells and CD3+. Leu-19+ T cells. The CD3+, Leu-19+, T cells mediated low levels of non-MHC-restricted cytotoxicity against K562, but did not respond to bacterial contact, even though rIL 2 could augment their lytic activity slightly. However, the cytotoxic activity of CD3-, Leu-19+ NK cells was significantly augmented by bacterial contact. Within the CD3-, Leu-19+ NK cell population both CD16+ and CD16- cells responded to bacterial activation. The CD3-, CD16-, Leu-19+ cells constituted 1 to 4% of the Percoll-fractionated low buoyant density lymphocytes and accounted for the activation seen within the CD16- lymphocyte population. Thus bacterial stimulation of NK activity seems to be mediated for the most part via CD16+, Leu-19+ cells, and a minor overall contribution is mediated via CD3-, CD16-, Leu-19+ cells. No apparent involvement of T cells was seen in the lytic response of lymphocytes to bacterial contact.

Bacterial induction of human activated lymphocyte killing and its inhibition by lipopolysaccharide (LPS)

Peripheral blood lymphocytes were incubated with glutaraldehyde-fixed Salmonella bacteria. This resulted in rapid activation of nonspecific cytotoxic potential of the lymphocytes. Both originally noncytotoxic, high-density Percoll-fractionated cells, and cytotoxic natural killer (NK) cell-enriched low-density cells were activated. The induction of originally noncytotoxic cells into activated killer (AK) cells was apparently independent of interferon (IFN), whereas the activation of the NK cell-enriched fractions also involved IFN production. Neither the AK nor NK activity were associated with significant bactericidal activity. The IFN-independent induction of AK activity was not dependent on the O-antigenic polysaccharide part of the lipopolysaccharide (LPS) on the bacterial cell surface, because both smooth (S) strains with differing O-antigenic structures (S-4,12 and S-6,7) and a rough (Re) strain without O-antigen were effective inducers. Isolated LPS, and especially alkali-hydrolyzed (O-deacylated, detoxified) LPS (ALPS) interfered with the induction of cytotoxicity. At concentrations of 10 to 30 micrograms/ml, ALPS totally inhibited the induction of AK activity without affecting the endogenous NK activity. Thus contact with bacteria can lead to the emergence of AK cells, and a bacterial product can effectively block this activation. These phenomena stress the complexity of interactions with host defenses that can take place during bacterial infection.

Comparison of diazepam and midazolam for sedation during local anaesthesia for bronchoscopy

Bronchoscopy was performed in 76 outpatients using local anaesthesia plus diazepam 0.2 mg kg-1 i.v. or midazolam 0.05 or 0.1 mg kg-1 i.v. Patient co-operation and ease of bronchoscopy were good in all patients. Two hours after injection, 67% (diazepam 0.2 mg kg-1), 36% (midazolam 0.05 mg kg-1) and 75% (midazolam 0.1 mg kg-1) of the patients failed to recall the insertion of the bronchoscope. Similarly, when asked on the following day, only 22%, 52% and 8%, respectively, of the patients remembered bronchoscopy. Two hours after sedation, the patients' performances in three psychomotor tests were similar to those measured before sedation in each group, but the patients' ability to stand steadily and walk along a straight line reverted to normal significantly (P less than 0.05) more slowly in patients receiving midazolam 0.1 mg kg-1 than in the patients given diazepam. The results suggest that midazolam offers no advantage over diazepam in terms of speed of recovery of psychomotor function, when doses of similar potency are given for bronchoscopy.

Adjuvant postoperative radiotherapy, chemotherapy, and immunotherapy in stage III breast cancer

One hundred twenty pathologically confirmed operable Stage III (T3N0-2) breast cancer patients were randomized to receive either postoperative radiotherapy or chemotherapy, or a combination of these, with or without levamisole immunotherapy. Radiotherapy was given to regional lymph node areas and chest wall. Chemotherapy consisted of 6 cycles of Adriamycin (doxorubicin) (45 mg/m2), vincristine (1.2 mg/m2) intravenously, and cyclophosphamide (200 mg/m2 for 5 days) perorally every 4 weeks. Peroral levamisole, 150 mg a day, 2 days weekly, was given as an immunotherapy. The 3-year results are described in this article. The effect of levamisole on the prognosis cannot be evaluated yet because of the short follow-up period. The disease-free survival was almost equal in each patient group, however, some benefit was achieved by levamisole (a shift of disease-free survival from 12 to 18 months). The patients receiving radiotherapy alone had the poorest prognosis: 68% had a recurrent tumor, and 57% were alive. In the chemotherapy group, the figures were 53% and 72%, respectively. Patients who received a combined treatment had the best prognosis: 13% had a recurrent tumor, and 90% survived 3 years. There was a statistically significant difference in the recurrence rate between any single therapy and the combined treatment (radiotherapy to combined treatment, P less than 0.001, chemotherapy to combined treatment, P less than or equal to 0.01 chi-square test). In overall survival, a statistically significant difference was reached between radiotherapy and combination treatment groups (P less than 0.01, chi-square test). Radiotherapy gave a good local control of the tumor, and chemotherapy decreased the number of metastases. The nonmetastatic axillary lymph node status and secondary amenorrhea or severe menstrual disturbances were of positive prognostic value. The side effects due to radiotherapy and chemotherapy were moderate and tolerable. The dose of Adriamycin had to be reduced only in four patients. All of the patients receiving chemotherapy had a transient total alopecia. Three of them had nonlethal arrhythmias, and one had skin rash. Levamisole was found very toxic with 9 cases of transient agranulocytosis, leading to the discontinuation of immunotherapy in 22 of 59 patients. Our results show that radiotherapy controls the tumor only locally and chemotherapy systematically, but the best patient-saving results are achieved with a combination of radiotherapy and chemotherapy. The disease-free and overall survival are statistically significant, and favor the combined therapy.

Caldwell-Luc operation in the treatment of childhood bronchial asthma

A follow-up study was carried out in 15 children with severe bronchial asthma. Chronic infection of the paranasal sinuses was connected with the unfavorable course of their bronchial asthma. As adenoidectomy and intranasal antrostomy had failed to cure the sinusitis, the Caldwell-Luc operation was performed at the age of 6-16 years. The follow-up examination was done 3-12 years after the radical operation of the maxillary sinuses. The majority of the patients had normal working capacity, and the need of medical treatment was reasonable. It is concluded that the Caldwell-Luc operation is indicated in children with severe bronchial asthma, when repeated respiratory infections are associated with asthmatic attacks and adenoidectomy and intranasal antrostomy have proved ineffective.

Suppressor cells of the human NK activity: characterization of the cells and mechanism of action

The surface marker characteristics and mechanism of action of small- to medium-sized NK suppressor lymphocytes, which can be found in both umbilical cord blood and adult peripheral blood, have been studied. Evidence suggestive of T-cell origin of the lymphocytes consisted of E-rosette formation, reactivity with OKT3 monoclonal antibody, and dot-like acid alpha-naphthyl acetate esterase (ANAE) staining pattern typical of T cells. Furthermore, no reactivity was seen with OKT6 and OKM1 monoclonal antibodies and the presence of intracytoplasmic immunoglobulin was excluded by indirect immunofluorescence microscopy, making the involvement of monocytes, B cells, and thymocytes less likely. As regards the mechanism of action, the role of prostaglandins was unlikely since indomethacin had no effect on the level of suppression. The role of soluble mediators was further examined by blocking cell secretion with monensin. In these experiments monensin treatment of the suppressor cells did not unwind suppression, suggesting that mechanisms other than secretion of suppressive factors were operative. The importance of cell-to-cell contact was demonstrated by the following observations: (i) A short contact of effector lymphocytes with suppressor lymphocytes, followed by their physical separation, resulted in decreased cytotoxic activity of the effector cells. (ii) Suppression could be mediated through Nuclepore filters, which allowed cell processes to pass through the filter, but not through filters which did not allow cell-to-cell contact. The suppressor cells were resistant to irradiation (2500 rad) and treatment with dexamethasone and puromycin. Viable cells were not needed, since paraformaldehyde-fixed suppressor cells could also mediate inhibition of K562 killing.

Suppressor cells of natural killer activity in normal and tumor-bearing individuals

Suppressor cells of the human natural killer activity were found in normal peripheral blood and in the blood of patients with untreated primary carcinomas. When lymphocytes from healthy donors were fractionated by Percoll density gradient centrifugation, small lymphocytic, high-density cells inhibited K562 killing in 9/55 consecutively tested cases, and lymphocytes from tumor patients in 1/25 consecutively tested cases. Further fractionation of the suppressor cells was achieved by EA rosetting, since strong suppressor cell activity was seen in the population of cells forming EA rosettes with antibody-coated erythrocytes, whereas the nonrosette-forming cells did not generally suppress. Out of the 33 further fractionated samples from healthy donors, 20 rosette-forming lymphocytic cell fractions exerted strong suppression and out of the 7 samples from tumor patients 2 exerted suppression after EA rosetting. The increase in suppression after EA rosetting was partly due to enrichment of suppressor cells, and partly due to activation of FcR-positive suppressor cells after exposure to immune complexes. The involvement of soluble immune complexes, possibly retained on the suppressor cell surface, was ruled out by the following criteria (i) trypsin and pronase treatment of suppressor cells did not inhibit suppression, (ii) protein A had no effect on the level suppression, and (iii) suppression was also seen with cells which had not been exposed to immune complexes.

The effect of instrumentation with a telescope during bronchoscopy on arterial oxygen tension and acid-base balance

The effect of instrumentation with a telescope during bronchoscopy on the arterial oxygen tension and acid-base status was studied in 17 unselected, anaesthetized patients using a ventilating technique based on Sanders' method (1). After ventilating the patients with a bronchoscope and a telescope in the trachea, in the left main bronchus or in the right main bronchus, the PaO2 value was always statistically significantly higher than after ventilating only with a bronchoscope. During the course of the bronchoscopy as well as after 1 h in the recovery room, the arterial acid-base status was within normal limits and the mean PaO2 value during bronchoscopy ranged from 175 to 240 mmHg (23.3-31.9 kPa) and was 138 mmHg (18.4 kPa) in the recovery room when the patients breathed about 35% oxygen in air. The present results suggest that instrumentation with a telescope during bronchoscopy ameliorates rather than impairs the ventilation and oxygenation of the patients.

Interferon-induced autologous reactivity of human natural killer cells

The reactivity of human natural killer (NK) cells against normal autologous target cells was studied. The following major observations were made: (i) non-stimulated NK cells did not lyse autologous target cells, although allogeneic cells were killed to some extent. However, treatment of effector cells with interferon (IFN) resulted in induction of autologous cytotoxicity, and both autologous and allogeneic fibroblast targets were efficiently killed without preference. This was demonstrated both with unfractionated lymphocytes and with effector cells highly enriched in large granular lymphocytes (LGL). (ii) NK cells bound to autologous cells as efficiently as to allogeneic cells. The cells binding to autologous cells were able to lyse K562 cells, demonstrating their NK nature. After stimulation with IFN autologous cells were also killed. (iii) The exemption from autologous cytotoxicity by the non-stimulated NK cells seemed to result from a block at a post-binding stage, and there did not appear to be any need for accessory cells in the induction of autologous reactivity by IFN treatment of the LGLs. The results thus point to important post-binding-stage regulatory mechanisms saving normal cells from the cytotoxic action of circulating NK cells and may help to understand the suggested role of NK cells in certain autoimmune diseases.