Title: Risk and characteristics of tuberculosis after anti-tumor necrosis factor therapy for
inflammatory bowel disease: A hospital-based cohort study from Korea
Version: 1 Date: 06 Jul 2021
Reviewer's report:
The message of the paper, that persons with LTBI should be treated before undergoing anti TNF
therapy is not new.  That the incidence of TB increases with age in the study population is also
to be expected, in keeping with the epidemiology of TB in South Korea.
1. The definition of LTBI used in this report (ie. "an abnormal chest X-ray in a patient who had
never completed TB or a positive TST or IGRA")  is unconventional. LTBI is usually defined
as a positive TST or IGRA test in the absence of clinical / radiological signs of active disease.
2. Were the patients on other immunosuppressive treatment besides the anti-TNF-alpha therapy?
If so, this information should have been included in the analysis.
3. Did the patients have other co-morbidities, eg. diabetes, end-stage renal failure, HIV which
also predisposed to TB?  This information should also have been included.
4. It is interesting that 3 cases who tested negative for LTBI and who developed active TB did so
within 2 months of starting anti-TNF therapy. Were they on other immunosuppressive therapy
which might have affected the IGRA performance? Could they already have had active disease
before starting anti-TNF therapy?
5. The patients who developed active TB many years after testing IGRA negative before starting
anti TNF alpha therapy were likely infected after testing negative. This gives support to inclusion
of LTBI testing in the regular surveillance of these persons such that LTBI treatment can be
given (after exclusion of active disease) in those who convert their IGRA test.
Title: Risk and characteristics of tuberculosis after anti-tumor necrosis factor therapy for
inflammatory bowel disease: A hospital-based cohort study from Korea
Version: 1 Date: 06 Jul 2021
Reviewer's report:
The message of the paper, that persons with LTBI should be treated before undergoing anti TNF
therapy is not new.  That the incidence of TB increases with age in the study population is also
to be expected, in keeping with the epidemiology of TB in South Korea.
1. The definition of LTBI used in this report (ie. "an abnormal chest X-ray in a patient who had
never completed TB or a positive TST or IGRA")  is unconventional. LTBI is usually defined
as a positive TST or IGRA test in the absence of clinical / radiological signs of active disease.
2. Were the patients on other immunosuppressive treatment besides the anti-TNF-alpha therapy?
If so, this information should have been included in the analysis.
3. Did the patients have other co-morbidities, eg. diabetes, end-stage renal failure, HIV which
also predisposed to TB?  This information should also have been included.
4. It is interesting that 3 cases who tested negative for LTBI and who developed active TB did so
within 2 months of starting anti-TNF therapy. Were they on other immunosuppressive therapy
which might have affected the IGRA performance? Could they already have had active disease
before starting anti-TNF therapy?
5. The patients who developed active TB many years after testing IGRA negative before starting
anti TNF alpha therapy were likely infected after testing negative. This gives support to inclusion
of LTBI testing in the regular surveillance of these persons such that LTBI treatment can be
given (after exclusion of active disease) in those who convert their IGRA test.
Please review this paper.
user
Title: Risk and characteristics of tuberculosis after anti-tumor necrosis factor therapy for
inflammatory bowel disease: A hospital-based cohort study from Korea
Version: 1 Date: 06 Jul 2021
Reviewer's report:
The message of the paper, that persons with LTBI should be treated before undergoing anti TNF
therapy is not new.  That the incidence of TB increases with age in the study population is also
to be expected, in keeping with the epidemiology of TB in South Korea.
1. The definition of LTBI used in this report (ie. "an abnormal chest X-ray in a patient who had
never completed TB or a positive TST or IGRA")  is unconventional. LTBI is usually defined
as a positive TST or IGRA test in the absence of clinical / radiological signs of active disease.
2. Were the patients on other immunosuppressive treatment besides the anti-TNF-alpha therapy?
If so, this information should have been included in the analysis.
3. Did the patients have other co-morbidities, eg. diabetes, end-stage renal failure, HIV which
also predisposed to TB?  This information should also have been included.
4. It is interesting that 3 cases who tested negative for LTBI and who developed active TB did so
within 2 months of starting anti-TNF therapy. Were they on other immunosuppressive therapy
which might have affected the IGRA performance? Could they already have had active disease
before starting anti-TNF therapy?
5. The patients who developed active TB many years after testing IGRA negative before starting
anti TNF alpha therapy were likely infected after testing negative. This gives support to inclusion
of LTBI testing in the regular surveillance of these persons such that LTBI treatment can be
given (after exclusion of active disease) in those who convert their IGRA test.
assistant