Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT01897909 |
Other study ID # |
HHECO |
Secondary ID |
|
Status |
Completed |
Phase |
|
First received |
|
Last updated |
|
Start date |
November 2011 |
Est. completion date |
July 29, 2021 |
Study information
Verified date |
July 2021 |
Source |
Bernhard Nocht Institute for Tropical Medicine |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Observational
|
Clinical Trial Summary
The main objective of the study is to investigate the impact of H. pylori infection on immune
activation and clinical outcome in HIV patients.
Other specific study objectives are:
1. To investigate the effects of H. pylori infection on immune activation and the T-cell
profile in HIV positive patients and compare those with HIV negative controls.
2. To assess the influence of H. pylori infection on virological and immune parameters, and
on clinical progression of HIV infection (WHO stage, opportunistic infections).
3. To assess the prevalence of H. pylori infection among HIV patients in the Komfo Anokye
Teaching Hospital.
4. To assess the prevalence of gastrointestinal symptoms in HIV patients in Kumasi.
5. To assess the association of H. pylori infection with gastrointestinal symptoms and
pathology in HIV patients.
6. To compare the clinical and immunological response to antiretroviral therapy and in
HIV-patients with and without concomitant H. pylori infection.
Description:
Study design:
Observational case control study with longitudinal follow up
Recruitment:
1000 HIV patients regularly attending to the KATH HIV clinic will be screened for H. pylori
infection and other parasitic gastrointestinal infections (as possible confounders).
Demographic, clinical and immunological data of those patients will be documented by study
physicians.
Two groups with each 100 patients with H. pylori infection and 100 patients without H. pylori
infection are then selected, matched according to sex, age, baseline HIV viral load, CD4 cell
count and other confounders.
100 healthy blood donors without HIV infection are equally screened for H. pylori and other
gastrointestinal infections and serve as a control group.
Study procedures:
Baseline:
Eligible patients will be recruited after the study procedure and potential risks associated
with participating in the study have been explained and written informed consent has been
obtained. The inclusion into the study shall in no way affect the decision to initiate HAART
or the choice of antiretroviral drugs. Patients may withdraw consent to participate in part
or in full at any time during the study without giving reasons. The withdrawal of consent
will in no way negatively affect the further management. Recruitment will begin after ethical
approval has been obtained from the appropriate authorities.
Baseline demographic, clinical and socioeconomic data, as well as the medical history will be
documented by the attending physicians involved in HIV services, who are blinded to
immunological parameters (except CD4 cell count) and stool test results. Routine laboratory
parameters will be extracted from patient's folders, including CD4 cell count, full blood
count as well as liver and kidney function tests.
Stool sample:
Patients are asked to provide a fresh stool sample to be tested for worm eggs, protozoa and
H. pylori. After concentration and preparation with sodium acetate-acetic acid-formalin
(SAF), specimens are stained with iodine and kinyoun solution for microscopy. Untreated fresh
stool is frozen at -80°C for H. pylori testing using a commercially available H. pylori stool
antigen test (Premier Platinum HpSA Plus, Meridian) according to the specifications of the
manufacturer.
Blood sample:
A venous blood sample (2x 8ml CPT tube, Becton Dickinson) is taken together with the blood
collection for the routine laboratory investigations. Plasma is separated for the analysis of
cytokines by Elisa or cytometric bead arrays (CBA) and the remaining plasma is stored at
-80°C. Peripheral blood mononuclear cells (PBMC) are isolated according to the manufacturer's
specifications and prepared for further testing by flow cytometry. A proportion of PBMC will
be stored in liquid nitrogen for later analysis. Plasma samples will be mainly used to assess
the cytokine profile (inflammatory and TH1/TH2 cytokines) by ELISA and multi-bead flow
arrays. PBMC will be analysed by flow cytometry to determine the frequency and phenotype of
Treg, defined as CD4+, CD25+, FoxP3+ cells, and the activation status and T-cell profile
(e.g. CD3, CD4, CD8, CD45RA, CD38, CD39, CD69), as well as apoptosis markers. Ex vivo
intracellular cytokine assay for IL-2, IL-4, IL-10 and IL-17 will be performed on
unstimulated and stimulated PBMC. FACS analyses will be conducted in the KATH immunology
laboratory, using the FACSCalibur flow cytometer (Becton Dickinson) and the CellQuest Pro
software.
Follow-up:
After baseline evaluation, patients are followed up for one year. 12 months after the
baseline evaluation, a venous blood sample (2x8ml CPT) is taken and the immunological
parameters are repeated as specified for the baseline evaluation. Patients who receive
treatment of intestinal pathogens, or who are started on antiretroviral therapy, according to
clinical indication, will be asked to provide an additional blood sample for immunological
evaluation three months after initiation of treatment. In case of treatment for an intestinal
pathogen, a stool sample will also be collected after three months to confirm eradication.
End points:
Primary end points:
1. Frequency and activation status of T-cell subsets in HIV positive patients with versus
without H. pylori infection
2. Change of CD4 cells and HIV viral load in HIV positive patients with versus without H.
pylori infection during follow-up
3. Incidence of clinical events in HIV positive patients with versus without H. pylori
infection during follow-up
Secondary end points:
1. Prevalence of H. pylori infection in HIV patients in Kumasi, Ghana, compared to blood
donors
2. Prevalence of infection with helminth and other gastrointestinal parasites in HIV
patients in Kumasi, Ghana, compared to blood donors
3. Prevalence and risk factors for gastrointestinal infections in HIV patients in Kumasi,
Ghana
4. Association of gastrointestinal infections with gastrointestinal symptoms
5. Association of gastrointestinal infections with nutrition status, wasting and anemia in
HIV patients in Kumasi, Ghana
Treatment regimens:
The management of the HIV infection will be carried out according to national and
institutional guidelines and will not be influenced by the study participation. Patients
found to be infected with pathogen parasites (e. g. Ascaris lumbricoides) will be offered
treatment. Patients with H. pylori infection and pertinent symptoms will be offered
eradication therapy according to national guidelines. If treatment costs are not covered by
the National Health Insurance Scheme (NHIS), costs will be covered by the study budget.
Interventions:
No interventions are carried out within this study.
Sample size calculation:
Calculations on the planned sample size were done but not quoted since not well
substantiated. Since there exist no data on the alterations of T-cell populations during H.
pylori infection, a substantiated sample-size analysis is not possible. We assume a
difference of the frequency of regulatory T cells (Treg), as one key end point, in the range
of 1-2%, as the minimum to be clinically significant. To demonstrate a significant difference
of 1% between the groups with a statistical power of 0.9 and α=0.05, using the unpaired,
2-sided t-test, a sample size of 380 patients would be needed. No reliable data exist on the
prevalence of H. pylori infection among HIV patients in Ghana. According to data from other
African countries, we assume a prevalence of 60-80%. To be sure to obtain sufficient H.
pylori negative patients and to be able to select a matched group of H. pylori uninfected
patients, we still suggest screening 1000 HIV infected patients. All patients recruited and
screened for H. pylori will be analysed for clinical progression of HIV disease. Likewise,
there exist no data to estimate the consequences for the clinical course. However, such
differences are difficult to identify due to the high variability of the clinical course of
HIV disease, and the multiplicity of confounders.
Statistical analysis:
Continuous variables are to be compared by paired Student's t-tests or Wilcoxon signed rank
test depending on statistical distributions. Linear regression analysis and Fisher's
transformation test will be used for continuous variables. Proportions will be compared by
chi-square tests. Multiple regression analysis and logistic regression analysis will be
performed as appropriate in order to correct for confounders. A p-value <0.05 will be
considered statistically significant.