Tonsillar hyperplasia and recurrent acute tonsillitis in children: Immunohistochemical evaluation of the lymphatic tissue

Simple hypertrophic tonsils have more active innate immune and inflammatory responses than hypertrophic tonsils with recurrent inflammation in children

Background

Tonsil hypertrophy has negative impact on children’s health, but its pathogenesis remains obscure despite the fact that numerous bacteriological studies have been carried out. Understanding the innate immune and inflammatory states of hypertrophic tonsils with different clinical manifestations is of great significance for defining the pathogenesis of tonsil hypertrophy and establishing treatment strategies. The present study was undertaken to examine the characteristics of innate immunity and inflammation in children with hypertrophic palatine tonsils and different clinical manifestations.

Methods

Tonsil tissues were surgically removed from the patients and classified based on the patients’ clinical manifestations. The patients were divided into three groups: 1) Control group; 2) Tonsil Hypertrophy (TH) group; and 3) Tonsil Hypertrophy combined with Recurrent Infection (TH + RI) group. The immune and inflammatory statuses of these tissues were characterized using qRT-PCR and ELISA methods.

Results

Viral protein 1 (VP1) was highly expressed in TH group, but not in TH + RI group. In TH group, elevated expression was observed in the innate immune mediators, including retinoic acid-inducible gene I (RIG-I), interferon alpha (IFN-α), mitochondrial antiviral-signaling protein (MAVS), NLR family pyrin domain containing 3 (NLRP3), toll-like receptor (TLR) 4 and TLR7. Consistent with the innate immune profile, the expression of inflammatory markers (IL-1β, NF-κB and IL-7) was also significantly elevated in TH group. Meanwhile, the COX-2/PGE2/EP4 signaling pathway was found to be involved in the inflammatory response and the formation of fibroblasts.

Conclusions

Innate immune and inflammatory responses are more active in simple hypertrophic tonsils, rather than hypertrophic tonsils with recurrent inflammation. A local relative immune deficiency in the hypertrophic tonsils may be a causative factor for recurrent tonsillitis in TH + RI. These differences, together with the patient’s clinical manifestations, suggest that tonsillar hypertrophy might be regulated by diverse immune and/or inflammatory mechanism through which novel therapeutic strategies might be created.

Lingual salivary gland hypertrophy and decreased acinar density in chagasic patients without megaesophagus

Although the salivary glands present several functions, there are few studies evaluating these glands in Chagas disease (CD). This study aimed to compare the percentage of collagen, the presence of inflammation, the density of chimase and tryptase mast cells, the area and density of lingual salivary gland acini in autopsied individuals with and without (CD). We analyzed 400 autopsy reports performed in a tertiary public hospital from 1999 to 2015 and selected all the cases in which tongue fragments were collected (27 cases), 12 with chronic CD without megaesophagus (CH) and 15 without CD (non-chagasic - NC). The histological sections of the tongue were stained by Picrosirius red for collagen evaluation and Hematoxylin-eosin for morphometric evaluation of salivary gland acini and inflammation. Anti-chimase and anti-tryptase antibodies were used for the immunohistochemical evaluation of mast cells. The chagasic patients presented higher volume and lower density of salivary glands acini. There was no difference in the collagen percentage, inflammation and density of mast cell chymase and tryptase between the groups. Although we did not observe a significant difference between the groups regarding the collagen percentage, inflammatory process and mast cell density, our results suggest that even without megaesophagus, chagasic patients present hypertrophy of the lingual salivary glands and lower acinar density probably due to mechanisms independent of the esophagus-glandular stimulus.