Microbiological profile of adenoid hypertrophy correlates to clinical diagnosis in children

Abstract

Objective: Adenoid hypertrophy is a common condition in childhood, which may be associated with recurring acute otitis media (RAOM), otitis media with effusion (OME), and obstructive sleep apnea syndrome (OSAS). These different clinical characteristics have some clinical overlap; however, they might be explained by distinct immunologic and infectious profiles and result in various histopathologic findings of adenoid specimens.

Methods: A total of 59 children with adenoid hypertrophy undergoing adenoidectomy were studied. Three series of identical adenoid specimens were processed to hematoxylin-eosin (H.E.) and Gram staining and to respiratory virus specific real-time PCR, respectively.

Results: According to the clinical characteristics, patients were recruited into three groups: RAOM (n = 25), OME (n = 19), and OSAS (n = 15). Bacterial biofilms were detected in 21 cases, while at least one of the studied respiratory viruses was detected in 52 specimens. RAOM cases were significantly associated with biofilm existence (n = 20, P < 0.001). In contrast, OME group was characterized by the absence of bacterial biofilm and by normal mucosa. Showing a statistically significant correlation, all OME cases were positive for human bocavirus (HBoV, P < 0.001).

Conclusions: Bacterial biofilms might contribute to the damage of respiratory epithelium and recurring acute infections resulting in RAOM. In OME cases persisting respiratory viruses, mainly HBoV, can cause subsequent lymphoid hyperplasia leading to ventilation disorders and impaired immunoreactivity of the middle ear cleft.

Figure 1

Graphic representation of respiratory virus specific real-time PCR results in different patient groups. RAOM: recurring acute otitis media; OME: otitis media with effusion; OSAS: obstructive sleep apnea syndrome.

Figure 2

Histopathologic representation of the respiratory epithelium in adenoid specimens of patients from OME and RAOM groups. (A1) At low magnification, regular columnar epithelium can be detected (black arrow, H.E.). (A2) Higher magnification view of the previous section. Black arrow indicates intact ciliated cells. (A3) Biofilm structures cannot be detected on the surface of epipharyngeal epithelium (Gram). (A4) Higher magnification view of the previous section. (B1) The epithelial layer is disintegrated and covered by a thick eosinophilic structure (black arrow, H.E.). (B2) At higher magnification, biofilm layer is a well identifiable structure (black arrow). (B3) Gram staining reveals a bacterial biofilm consisted of individual colonies of Gram-positive cocci (black arrow). (B4) Higher magnification view of the previous section. White arrow indicates Gram-positive cocci in a chain-pattern of streptococci.

Figure 3

Histopathologic representation of the stromal substance in adenoid specimens of patients from the OME and RAOM groups. (A1) Normal centrum germinativum (white arrow, H.E.). (A2) Higher magnification of the previous section. White arrow indicates large lymphocytes, while immunoblasts and centroblasts are shown by black arrow. (A3) Agarose gel electrophoresis of real-time PCR products of the identical specimen. Positive reactions were shown for Adenovirus (AdV), Human Bocavirus (hBoV), and for Rhinovirus-Enterovirus (RV/EV) serotypes. CC: cellular control. (B1) Disintegrated stromal substance without centrum germinativums (white arrow, H.E.). (B2) At higher magnification view, several polymorphonuclear cells (black arrow) and plasmocytes (white arrow) can be identified. (B3) Agarose gel electrophoresis of real-time PCR products of the identical specimen. The sample showed individual expression of Adenovirus (AV). CC: cellular control.