A new assay that is highly sensitive and specific for detecting all members of the Helicobacteraceae family found none of the bacteria in 78 specimens of hyperplastic adenoids, according to a report in the October issue of the Archives of Otolaryngology – Head & Neck Surgery.
"We believe that our findings show that adenoid tissue does not serve as a reservoir for species of the Helicobacteraceae family. This suggests that colonization of the tissue by these bacteria is not a factor contributing to adenoid hyperplasia," said Damian J. Hussey, Ph.D., of the department of surgery, Flinders Medical Center, Adelaide (Australia), and his associates.
When other researchers found evidence that gastric contents could reach the middle ear via the nasopharynx and eustachian tubes, it was hypothesized that gastroesophageal or laryngopharyngeal reflux might cause inflammatory changes that could eventually lead to adenoid hyperplasia. There have been several reports that H. pylori was detected in hyperplastic adenoids in children, but the detection rate has been extremely variable.
This is most likely because different methods of detection were used in each case, because until now no single method of identifying H. pylori in this tissue has proved to be very accurate, the investigators said.
Dr. Hussey and his colleagues developed a highly sensitive and specific reverse transcription–polymerase chain reaction (PCR) assay to detect all Helicobacter organisms. Their assay is capable of detecting the equivalent of a single Helicobacteraceae bacterium within a sample.
They then tested the assay in 78 biopsy specimens taken from children aged 2-10 years who underwent adenoidectomy for sleep-disordered breathing at two pediatric hospitals in Adelaide. They also examined specimens of normal adenoids collected from 15 children undergoing routine dental surgical procedures.
The assay readily detected H. pylori in positive control samples, but did not detect H. pylori in any of the hyperplastic or normal adenoid samples. One organism – Candidatus Wolinella africanus – was the only Helicobacteraceae family member identified, and it was found in only one hyperplastic adenoid (Arch. Otolaryngol. Head and Neck Surg. 2011;137:998-1004).
In addition, an experienced histopathologist who was blinded to the assay results examined a subset of 27 tissue samples to identify any micro-organisms that might have been present. "Special attention was paid to the crypts of the epithelium because this is where H. pylori is often detected in gastric biopsy specimens," the researchers noted.
Overall, "we found surprisingly few bacteria in our hyperplastic adenoid specimens." Only two rod-like bacterial organisms were detected in a single specimen, and they were not consistent with H. pylori.
"We conclude that H. pylori and other Helicobacteraceae family members are not major contributors to the development of hyperplastic adenoids in children," Dr. Hussey and his associates said.
"However, the detection of Candidatus W. africanus in a hyperplastic adenoid sample indicates that gastric contents can reach the adenoid, so occasional reflux episodes may form part of the pathophysiologic characteristics of this disease."
This study was supported in part by the Channel 7 Children’s Research Foundation. No financial conflicts of interest were reported.