Quantification of cells expressing markers of proliferation and apoptosis in chronic tonsilitis

During chronic tonsillitis, the relationship between proliferation and apoptosis of lymphocytes in tonsillar follicles can be disturbed, which gives rise to attenuation of tonsil immunocompetence and diminishing its contribution in systemic immunity. In this study, we have quantified the cells expressing the markers of proliferation and apoptosis in the follicles of the palatine tonsil. Six tonsils from patients aged 10-29 years with hypertrophic tonsillitis and five tonsils from patients aged 18-22 years with recurrent tonsillitis were studied. The sections of paraffin blocks of tonsillar tissue were stained by the immunohistochemical LSAB/HRP method with the utilisation of antibodies for: Ki-67 antigen-cell marker of proliferation; Bcl-2 and survivin anti-apoptotic factors and Fas/CD95, caspase-3 and Bax pro-apoptotic factors. The size of lymphoid follicles, i.e. mean follicle area and number of lymphoid follicle immunopositive cells per mm2 of a slice area, i.e. numerical areal density were determined by the quantitative image analysis. The localisation of Ki-67, Bcl-2, survivin, Fas/CD95, caspase-3 and Bax- immunopositive cells inside the palatine tonsil was similar in both types of tonsillitis. The number of Ki-67 immunopositive cells was significantly (p < 0.01) larger in the tonsils with hypertrophic tonsillitis (14681.4 ± 1460.5) in comparison to those with recurrent tonsillitis (12491.4 ± 2321.6), although the number of survivin and caspase-3 immunopositive cells was significantly (p < 0.05) larger in recurrent tonsillitis (survivin, 406.9 ± 98.4; caspase-3, 350.4 ± 119.4) when compared to those with hypertrophic tonsillitis (survivin, 117.4 ± 14.5; caspase-3, 210 ± 24). Our results show that the rate of the proliferation and apoptosis of follicular lymphocytes is different in various types of tonsillitis. This suggests that the immunological potential of the palatine tonsil varies in patients with hypertrophic and recurrent tonsillitis, which in practice poses a dilemma over the choice of conservative or surgical treatment.