Reviewer's report
Title:Evaluation of a new fluorescence quantitative PCR test for diagnosing
Helicobacter pylori infection in children
Version: 1Date:24 August 2012
Reviewer: Giulia Martina Martina Cavestro
Reviewer's report:
A new fluorescence quantitative PCR (fqPCR) accuracy to detect HP urease A
gene is discussed in the paper by Ou et al.
138 children gastritis biopsy specimens were sent for histological examination,
rapid urease test (RUT), 13C-urea breath test and fqPCR. Gastric fluids and
dental plaques were also collected in order to perform fqPCR for the HP urease
A gene detection analysis. Results showed 27.5% of the patients were
Hp-positive infection by reference standard. Gastric mucosa fqPCR not only
detected all 38 Hp-positive patients but also detected 8% of the reference
standard negative children or 10.7% of the histology-negative samples.
Therefore, gastric mucosa fqPCR identified 33.3% children with Hp infection,
significantly higher than reference standard or histology (p<0.01). Both gastric
fluid and dental plaque fqPCR only detected 23.2% and 21.7% children with Hp
infection respectively and was significantly less sensitive than mucosa fqPCR
(p<0.05). Authors concluded gastric mucosa fqPCR for the HP urease A gene
detection was more sensitive than histology, RUT, 13C-urea breath test alone or
in combination to detect H. pylori infection in children with chronic gastritis. Either
gastric fluid or dental plaque PCR is as reliable as 13C-urea breath test for Hp
detection.
Recently, assays based on PCR technology were employed to detect the
presence of H. pylori DNA using several gene targets including urease A gene,
the 26-kDa species-specific antigen (SSA) gene, the phosphosamine mutase
(glmM) and the cagA gene (UreC PCR).
The question posed by the authors is narrowed, methods are appropriate and
pinned down and manuscript adheres to the relevant standards for reporting and
data deposition.
The largest limitation of the work is not clearly stated and therefore an accurate
revision is required. (Major Compulsory Revision)
Authors made no mention of immunohistochemical stain for Hp infection.
Immunohistochemical stain is readily available in routine histology laboratories
and it is a cost effective way of demonstrating bacteria with the highest
sensitivity, specificity and interobserver agreement.
In order to assess fqPCR higher accuracy in comparison to histology, I suggest
to perform in all gastric biopsy specimens the immunohistochemical stain for Hp
infection too.
Authors concluded fqPCR is more sensitive than histology and it could be a new
gold standard for Hp detection. Indeed, the comparison between fqPCR and
histology has to be performed also with immunohistochemical stain method.
Finally, I would suggest to add in the statistical analysis confidence intervals and
p value corrections (if applied).
Level of interest: An article of limited interest
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
None
Reviewer's report
Title:Evaluation of a new fluorescence quantitative PCR test for diagnosing
Helicobacter pylori infection in children
Version: 1Date:24 August 2012
Reviewer: Giulia Martina Martina Cavestro
Reviewer's report:
A new fluorescence quantitative PCR (fqPCR) accuracy to detect HP urease A
gene is discussed in the paper by Ou et al.
138 children gastritis biopsy specimens were sent for histological examination,
rapid urease test (RUT), 13C-urea breath test and fqPCR. Gastric fluids and
dental plaques were also collected in order to perform fqPCR for the HP urease
A gene detection analysis. Results showed 27.5% of the patients were
Hp-positive infection by reference standard. Gastric mucosa fqPCR not only
detected all 38 Hp-positive patients but also detected 8% of the reference
standard negative children or 10.7% of the histology-negative samples.
Therefore, gastric mucosa fqPCR identified 33.3% children with Hp infection,
significantly higher than reference standard or histology (p<0.01). Both gastric
fluid and dental plaque fqPCR only detected 23.2% and 21.7% children with Hp
infection respectively and was significantly less sensitive than mucosa fqPCR
(p<0.05). Authors concluded gastric mucosa fqPCR for the HP urease A gene
detection was more sensitive than histology, RUT, 13C-urea breath test alone or
in combination to detect H. pylori infection in children with chronic gastritis. Either
gastric fluid or dental plaque PCR is as reliable as 13C-urea breath test for Hp
detection.
Recently, assays based on PCR technology were employed to detect the
presence of H. pylori DNA using several gene targets including urease A gene,
the 26-kDa species-specific antigen (SSA) gene, the phosphosamine mutase
(glmM) and the cagA gene (UreC PCR).
The question posed by the authors is narrowed, methods are appropriate and
pinned down and manuscript adheres to the relevant standards for reporting and
data deposition.
The largest limitation of the work is not clearly stated and therefore an accurate
revision is required. (Major Compulsory Revision)
Authors made no mention of immunohistochemical stain for Hp infection.
Immunohistochemical stain is readily available in routine histology laboratories
and it is a cost effective way of demonstrating bacteria with the highest
sensitivity, specificity and interobserver agreement.
In order to assess fqPCR higher accuracy in comparison to histology, I suggest
to perform in all gastric biopsy specimens the immunohistochemical stain for Hp
infection too.
Authors concluded fqPCR is more sensitive than histology and it could be a new
gold standard for Hp detection. Indeed, the comparison between fqPCR and
histology has to be performed also with immunohistochemical stain method.
Finally, I would suggest to add in the statistical analysis confidence intervals and
p value corrections (if applied).
Level of interest: An article of limited interest
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
None
Please review this paper.
user
Reviewer's report
Title:Evaluation of a new fluorescence quantitative PCR test for diagnosing
Helicobacter pylori infection in children
Version: 1Date:24 August 2012
Reviewer: Giulia Martina Martina Cavestro
Reviewer's report:
A new fluorescence quantitative PCR (fqPCR) accuracy to detect HP urease A
gene is discussed in the paper by Ou et al.
138 children gastritis biopsy specimens were sent for histological examination,
rapid urease test (RUT), 13C-urea breath test and fqPCR. Gastric fluids and
dental plaques were also collected in order to perform fqPCR for the HP urease
A gene detection analysis. Results showed 27.5% of the patients were
Hp-positive infection by reference standard. Gastric mucosa fqPCR not only
detected all 38 Hp-positive patients but also detected 8% of the reference
standard negative children or 10.7% of the histology-negative samples.
Therefore, gastric mucosa fqPCR identified 33.3% children with Hp infection,
significantly higher than reference standard or histology (p<0.01). Both gastric
fluid and dental plaque fqPCR only detected 23.2% and 21.7% children with Hp
infection respectively and was significantly less sensitive than mucosa fqPCR
(p<0.05). Authors concluded gastric mucosa fqPCR for the HP urease A gene
detection was more sensitive than histology, RUT, 13C-urea breath test alone or
in combination to detect H. pylori infection in children with chronic gastritis. Either
gastric fluid or dental plaque PCR is as reliable as 13C-urea breath test for Hp
detection.
Recently, assays based on PCR technology were employed to detect the
presence of H. pylori DNA using several gene targets including urease A gene,
the 26-kDa species-specific antigen (SSA) gene, the phosphosamine mutase
(glmM) and the cagA gene (UreC PCR).
The question posed by the authors is narrowed, methods are appropriate and
pinned down and manuscript adheres to the relevant standards for reporting and
data deposition.
The largest limitation of the work is not clearly stated and therefore an accurate
revision is required. (Major Compulsory Revision)
Authors made no mention of immunohistochemical stain for Hp infection.
Immunohistochemical stain is readily available in routine histology laboratories
and it is a cost effective way of demonstrating bacteria with the highest
sensitivity, specificity and interobserver agreement.
In order to assess fqPCR higher accuracy in comparison to histology, I suggest
to perform in all gastric biopsy specimens the immunohistochemical stain for Hp
infection too.
Authors concluded fqPCR is more sensitive than histology and it could be a new
gold standard for Hp detection. Indeed, the comparison between fqPCR and
histology has to be performed also with immunohistochemical stain method.
Finally, I would suggest to add in the statistical analysis confidence intervals and
p value corrections (if applied).
Level of interest: An article of limited interest
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
None
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