Tonsillar hypertrophy is a frequent disease at a developmental age. Tonsils consist of many lymphatic follicles adhering to the epithelium which covers the oral cavity and the mucose tunica of the throat. This is the area where contact with antigens takes place. These antigens are most often of a bacterial nature and are carried there with air and with food. It is estimated that constant contact with antigens is an uninterrupted process of lymphocyte direct stimulation in the tonsil, and it may provoke the reaction of the whole immunology system. Apart from the bacterial etiology which was documented some time ago, the essential feature is attributed to the individual form of the child suffering from tonsillar hypertrophy immunology system. In spite of the fact that ATT and AT is frequently carried out on children, the amount of scientific research dealing with the immunology system´s state in estimation of children qualified for this treatment is relatively low. We also have little knowledge of phenotype tonsillar T and B lymphocyte subpopulations. From the few studies on this subject, it can be stated that the percentage of T and B tonsillar lymphocytes is similar and that most of the cells producing cytokines, and plasmocytes producing antibodies lie in the space behind follicles. In comparison with the peripheral blood cells, more clones of CD4 cells in tonsils produce cytokines such as IL-2, IL-4 and gamma-IFN. It is thought, that IL?6 synthetized by tonsillar macrophages induces B lymphocytes to antibody synthesis, whereas IL-2 stimulates cell proliferation. Our previous studies have dealt with the state of the main subpopulations of blood and tonsillar lymphocytes. These lymphocytes have been examined using monoclonal antibodies by immunoenzymatic techniques.

Our investigations are in progress because they reveal vital disturbances in the number and activity of the peripheral blood lymphocytes of ill children, in comparison with healthy children of the same age. In this study, the results of investigations into children, re-operated on because of recurrent tonsillar hypertrophy, are demonstrated.

On the day of operation the patient´s blood (1 ml) was taken for heparin.

After tonsillar resection the lymphocytes were isolated from the extracted tissue. The number of lymphocytes was counted in a previously-prepared suspension.Their vitality was checked by counting the percentage of dead cells, stained with trypan blue, under a microscope. The percentage of cellular pairs was also counted. Cells isolated from tonsil and nuclear cells in full blood were marked by monoclonal antibodies. Those antibodies were labelled by fluorochromes (Dako and Coulter Co.), which detected the following antigens: CD2/CD19, CD3/CD4/CD8, CD5/CD20, CD4/CD45RA, CD8//CD11a, CD4/CD29, CD8/CD56 and HLA-DR, DP, DQ (MHC II class). The cells were analysed by flow cytometry (Epics XL, Coulter Co). Five thousand cells were counted. Lymphocytes were located by using anti-CD45 and CD14 antibodies. In every study the appropriate isotype control was applied. The control group consisted of 10 healthy children whose age was similar to age of operated children. Samples of their blood were taken for morphology and examinations of the lymphocyte subpopulations were made. Where possible, the healthy child´s examination was accompanied by the with operated child´s examinations. Statistical analysis was done using an unparametrical Wilcoxon´s test. Individual results by patient were analysed in comparison with the control range of results (average result ? 2SD).

Table 1 shows a comparison of the average percentage of separate subpopulations of blood in the healthy group, who had been operated on because of tonsillar hypertrophy for the first time, and of those children who had been re-operated for the second or third time. In both groups of operated children an essential rise in the percentage of T CD8+ lymphocytes was observed. In the group of children operated for the first time there was also an essential increase in the percentage of lymphocytes types T CD4+ CD29+ percentage. An important statistical decrease in T CD2+ lymphocytes was only noticed in the group of re-operated children. The second table shows a comparison of percentage values of lymphocyte subpopulations which were isolated from the removed tonsillar tissue because of hypertrophy which had recurred. The results, related to those of the subpopulation content in tonsils which were being removed for the first time, showed a vital increase in the percentage of CD3+ CD4+ lymphocytes. In CD4+ lymphocytes the subpopulation percentage of cells showing an expression of antigen CD29 increased. In re-operated tonsils there were more B lymphocytes of the phenotype CD5 CD20. Because average results do not always show when changes occur in individual patients, in the third table we show the results of the examinations of peripheral blood lymphocytes taken from two patients with tonsillar hypertrophy. These examinations took place on the operation day and 6 months after the treatment. The results are shown in comparison with the results from healthy children. Patient no.1 (3rd re-operation) disturbances were connected with a small decrease in the number of CD4 lymphocytes and an increased expression of HLA-MHCII class antigens. After the operation a decrease in the expression of antigens characteristic of T and B lymphocytes occurred and a population of T CD4+ CD8+ lymphocytes appeared. This patient was periodically examined and after 18th months re-operated again. During this time he was vaccinated with BCG and in control examinations after the vaccination, an increase of TCD2+ lymphocytes from 9.3% to 73.9% and CD3+ from 15.6% to 64.3% was estimated. The percentage of CD4+ increased from 8.2% to 30,9% before the next re-operation. The results of examinations on the day of the next re-operation again showed small deviations from normal (results not shown). In patient no. 2 (first re-operation) disturbances after the operation were similar to those which had occured before the operation.

The results of the above examinations confirm our previous observations as well as those of other authors that there exist vital disturbances in the expression of surface antigens that occur in children with tonsillar hypertrophy (2, 3, 4, 7).

These disturbances are of more concern after lymphocyte T (table 1 and 3). In some patients they also occur in the B lymphocyte population (table 3). Quality changes in the composition of the subpopulation of peripheral blood lymphocytes last for a relatively long time in the period after the operation (4). Because of the fact that changes that occurred just before the following re-operation were less strong than those observed after the previous operation, it is suggested that in some children normalisation of the lymphocyte subpopulation is parallel to tonsillar tissue hypertrophy. Therefore it can be supposed that a weak expression of lymphocytic antigens might be con- nected with a lack of stimulating factors, released from proliferating tonsil cells under the influence of antigens.The fact that in re-operated tonsillar tissue there are more T lymphocytes in comparison with tonsils operated on for the first time may support the above suggestion, but it does not exclude the supposition that because of this fact these tonsils are subject to renewed hypertrophy. The first possibility, the lack of stimulating factors, is supported by the observation that the percentage of lymphocytes with expression CD2 and CD3 returns to normal in the re-operated patient no.1 case after vaccination with BCG. The normalisation of CD4 expression occurred in his case only after the period following tonsillar hypertrophy. In the light of these and our previously presented examinations concerning the vital decrease of expression of immunoglobulin markers in B lymphocytes in children after adenotonsillotomy (2, 4), it can be asked whether children who after adenotonsillotomy have disturbances of the expression of antigens on peripheral blood lymphocytes, could be helped by introducing a controlled stimulation. The results of some examinations confirm the positive influence of bacterial ribosome stimulation on the increase in number, of CD3+, CD4+, CD3+, and CD8+ lymphocytes (5) in children with a tendency to severe recurrent infections, as well as on the increase of B lymphocytes in peripheral blood and tonsils, which synthetise surface immunoglobulins (6). Examinations of the patient´s immunology system should be followed by planned immunotheraphy and the application of immunotheraphy should be monitored using periodicall-repeated control examinations.