The Bcl-2 protein expression in germinal centers of hypertrophied adenoids in children

Abstract

The aim of this study was to evaluate Bcl-2 expression in the germinal centers of adenoid in children on the assumption that it can be treated as a marker of adenoidal tissue function. The study involved 95 children. The patients were divided into three age groups: aged up to 5, 5-10 and above 10 years. The analysed material were adenoids removed on the grounds of hypertrophy. Immunohistochemical analyses were carried out using monoclonal antibodies (DAKO/Bcl-2, No. M0887) directed against human Bcl-2 protein. The presence of Bcl-2 positive lymphocytes within the lymphoid follicles and Bcl-2 immunostaining were scored. The immunohistochemical staining showed Bcl-2 positive lymphocytes in the examined sections of adenoidal tissue and their characteristic location, mainly within the mantle zone. Bcl-2 reactivity was widespread in hyperplastic lymphoid tissue, including germinal centers surroundings, scattered cells within the germinal centers and the T-cell areas in general. We have not found statistically significant correlation between Bcl-2 expression and clinical status and change in Bcl-2 expression level according to age. The apoptosis presence within the germinal centers and its lack in mantle zone, the manifestation of which is Bcl-2 expression, is a sign of a proper lymphocytes maturation within lymphoid follicles. It seems that these processes are not influenced by age, so the adenoid involution is probably associated with the changes in the number of lymphoid follicles rather than change or inhibition of the processes that take place in them.

The Bak protein expression in germinal centers of hypertrophied adenoids in children

“…We have not found however statistically significant correlation between Bak expression in adenoid tissue and clinical status. Similarly to Bcl-2 expression in mantle zone lymphocytes of lymphoid follicle [7], Bak expression within the germinal center seems not to be affected by the clinical status of the child. However, it is accepted that during an acute infection the proportion of germinal center cells may increase due to the introduction of foreign antigen [19].…”

“…Similarly to our previous paper [7], on the same assumption of Bak protein as a marker of adenoid function, we tried in the current study to correlate this with some clinical features, such as accompanied tonsillar hyperplasia, otitis media with effusion onset, rhinitis chronica and history of recurrent upper respiratory tract infections. We have not found however statistically significant correlation between Bak expression in adenoid tissue and clinical status.…”

“…In our former paper [7] we described Bcl-2 expression level in the adenoid tissue in children on the assumption that it can be treated as a marker of adenoidal tissue function.…”

“…The presence of apoptosis within the germinal centers of adenoid, the indication of which is Bak expression and its lack in the mantle zone [7] is the proper B cells maturation marker within lymphoid follicles. Our finding show that these processes are not influenced by age and support our thesis that adenoid involution is rather the effect of changes in the number of lymphoid follicles that changes in them.…”

“…Because of the lack of data considering apoptosis and its mediators and their potential association with mechanisms of adenoid involution, we tried in our former paper to evaluate anti-apoptotic Bcl-2 expression in the germinal centers of adenoid in children [7]. In the current study we aimed to evaluate pro-apoptotic Bak expression in the germinal centers of adenoid in children on the assumption of the potential usefulness of Bak as adenoid function marker.…”