Performance characteristics of Allele-Specific PCR (ASPCR) in detecting drug resistance mutations among non-B HIV-1 Variants

Allele-Specific Polymerase Chain Reaction (ASPCR) is an affordable point-mutation assay whose validation could improve the detection of HIV-1 drug resistance mutations (DRMs) in resource-limited settings (RLS). We assessed the performance of ASPCR onforty-four non-B HIV-1 plasma samples from patients who were ARV treated in failure in N'Djamena-Chad. Viral RNA was reverse-transcribed and amplified using LightCycler® FastStart DNA MasterPLUS SYBR Green I. Detection of six major DRMs (K70R, K103N, Y181C, M184V, T215F, T215Y) was evaluated on Roche LightCycler®480 automated system (with dilutions 0.01-100%). ASPCR-results were compared to Sanger-sequencing (gold-standard). Correlations of mutation curves were excellent (R2 >0.97); all DRMs were detected with desirable mutant/wild-type threshold differences (ΔCt≥9) except K70R(ΔCtK70R=6; ΔCtK103N=13; ΔCtM184V=9; ΔCtT215F=12; ΔCtT215Y=12; ΔCtY181C=9) and positive controls were below required thresholds. Also, ASPCR reproducibility on DRMs was assessed by using dilutions of intra-assay and inter-assay coefficient of variations respectively with a threshold of less than 50(i.e.<0.50 variation) which are;: K70R (0.02-0.28 vs. 0.12-0.37), K103N (0.08-0.42 vs. 0.12-0.37), Y181C (0.12-0.39 vs. 0.31-0.37), M184V (0.13-0.39 vs. 0.23-0.42), T215F (0.05-0.43 vs. 0.04-0.45) and T215Y (0.13-0.41 vs. 0.19-0.41). DRM detection-rate by ASPCR vs Sanger was respectively: M184V (63.6% vs. 38.6%); T215F (18.1% vs. 9.1%); T215Y (6.8% vs. 2.3%); K70R (4.5% vs. 2.3%). K103N (22.7% vs. 13.6%); Y181C (13.6% vs. 11.4%). Correlations of mutation curves were excellent (R2 >0.97); all DRMs were detected with desirable mutant/wild-type threshold differences (ΔCt≥9) except K70R(ΔCtK70R=6; ΔCtK103N=13; ΔCtM184V=9; ΔCtT215F=12; ΔCtT215Y=12; ΔCtY181C=9) and positive controls were below required thresholds. Also, ASPCR reproducibility on DRMs was assessed by using dilutions of intra-assay and inter-assay coefficient of variations respectively with a threshold of less than 50(i.e.<0.50 variation) which are;: K70R (0.02-0.28 vs. 0.12-0.37), K103N (0.08-0.42 vs. 0.12-0.37), Y181C (0.12-0.39 vs. 0.31-0.37), M184V (0.13-0.39 vs. 0.23-0.42), T215F (0.05-0.43 vs. 0.04-0.45) and T215Y (0.13-0.41 vs. 0.19-0.41). DRM detection-rate by ASPCR vs Sanger was respectively: M184V (63.6% vs. 38.6%); T215F (18.1% vs. 9.1%); T215Y (6.8% vs. 2.3%); K70R (4.5% vs. 2.3%). K103N (22.7% vs. 13.6%); Y181C (13.6% vs. 11.4%). ASPCR appears more efficient for detecting DRMs on diverse HIV-1 non-B circulating in RLS like Chad.

Prevalence and evolution of transmitted HIV drug resistance in Belgium between 2013 and 2019

Background

To assess the prevalence and evolution of transmitted drug resistance (TDR) in Belgium, a total of 3708 baseline human immunodeficiency virus (HIV)-1 polymerase sequences from patients diagnosed between 2013 and 2019 were analyzed.

Methods

Protease and reverse-transcriptase HIV-1 sequences were collected from the 7 national Aids Reference Laboratories. Subtype determination and drug resistance scoring were performed using the Stanford HIV Drug Resistance Database. Trends over time were assessed using linear regression, and the maximum likelihood approach was used for phylogenetic analysis.

Results

A total of 17.9% of the patients showed evidence of TDR resulting in at least low-level resistance to 1 drug (Stanford score  ≥15). If only the high-level mutations (Stanford score ≥60) were considered, TDR prevalence dropped to 6.3%. The majority of observed resistance mutations impacted the sensitivity for nonnucleoside reverse-transcriptase inhibitors (NNRTIs) (11.4%), followed by nucleoside reverse-transcriptase inhibitors (6.2%) and protease inhibitors (2.4%). Multiclass resistance was observed in 2.4%. Clustered onward transmission was evidenced for 257 of 635 patients (40.5%), spread over 25 phylogenetic clusters.

Conclusions

The TDR prevalence remained stable between 2013 and 2019 and is comparable to the prevalence in other Western European countries. The high frequency of NNRTI mutations requires special attention and follow-up. Phylogenetic analysis provided evidence for local clustered onward transmission of some frequently detected mutations.

Impact of switch from tenofovir disoproxil fumarate-based regimens to tenofovir alafenamide-based regimens on lipid profile, weight gain and cardiovascular risk score in people living with HIV

Background

As cardiovascular diseases represent the main cause of non-AIDS related death in people living with HIV (PLWH) with undetectable viral load, we evaluated lipid profile, weight gain and calculated cardiovascular risk change after switching from tenofovir disoproxil fumarate (TDF)-based regimens to tenofovir alafenamide (TAF)-based regimens.

Methods

For this retrospective study, we selected HIV-infected patients with suppressed viral load who fitted in one of the two groups below: First group (TDF/TDF): Patients treated continuously with TDF-based regimens. Second group (TDF/TAF): Patients treated with TDF-regimens during at least 6 months then switched to TAF-regimens while maintaining other drugs unchanged. Available data included date of birth, gender, ethnicity, lymphocyte T CD4⁺ count, weight, height, blood pressure, current/ex/non-smoker, diabetes mellitus, familial cardiovascular event, lipid profile, duration and nature of antiretroviral therapy. Lipid parameters, weight and calculated cardiovascular risk using 5-year reduced DAD score algorithm [Friis-Møller et al. in Eur J Cardiovasc Prev Rehabil 17:491–501, 2010] were analyzed in each groups.

Results

Switching from TDF to TAF resulted in a significant increase in triglycerides levels, total cholesterol and HDL cholesterol. LDL cholesterol and total cholesterol/HDL ratio did not show significant changes. Calculated cardiovascular risk increased after switch from TDF- to TAF-based therapy.

Conclusions

Together with favorable outcomes at the bone and kidney levels, potential negative impact of TAF on lipid profile should be included in the reflection to propose the most appropriate and tailored ARV treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06479-9.

Impact of the COVID-19 pandemic situation on HIV care in Liège, Belgium

BACKGROUND

Background: The COVID-19 pandemic and associated containment measures dramatically affected the health care systems including the screening of human immunodeficiency virus and the management people living with HIV around the world by making the access to preventive care services and specific medical monitoring more difficult.

OBJECTIVE

Objective: To study the impact of the COVID-19 pandemic on the holistic care of people living with HIV in Liège (Belgium).

METHODS

Methods: In this retrospective observational study conducted in Liège University Hospital, we compared the out-patient follow-up of HIV-infected individuals as well as the number of new HIV diagnoses between 2019 and 2020 and between the different waves of the COVID-19 pandemic in 2020.

RESULTS

Results: In 2020, when compared to 2019, we observed a significant decrease in the number of new HIV diagnoses, especially during the first wave of the pandemic, and in the number of consultations undertaken by sexual health services, psychologists and specialists in infectious diseases at our HIV clinic. We also observed a decrease in the number of viral load assays and blood CD4 + T-cells count analyses performed, although we found less patients with HIV plasma viral load above 400 copies per mL in 2020. Finally, we noted a significant reduction in terms of screening of our HIV-infected patients for hepatitis C, syphilis, colorectal and anal cancers and hypercholesterolemia.

CONCLUSIONS

Conclusions: Our experience exhibits the deleterious impact of the COVID-19 pandemic on the HIV care and the need to implement new strategies to guarantee its continuum.

Chronic and Early Antiretroviral Therapy Impact Human Immunodeficiency Virus (HIV) Serological Assay Sensitivity, Leading to More False-Negative Test Results in HIV Diagnosis

This retrospective study evaluated the reactivity of 3 human immunodeficiency virus (HIV) confirmatory assays (INNO-LIA, Geenius, and MP) and 7 HIV rapid tests on samples from 2 different study populations in Belgium. For the early-treated cohort (83 HIV-1 adult patients treated within 3 months after infection), HIV-1 diagnosis was not obtained in at least 1 confirmatory assay in 12.0% (10/83) and in an HIV rapid test in 31.3% (26/83). Confirmation assay sensitivities ranged from 87.5% to 95.2%, whereas rapid test assay sensitivities ranged from 75.9% to 100%. The time to treatment initiation or the length of time on treatment did not have a statistical influence on the probability to obtain a false-negative test result. The fastest reversion was demonstrated after 4 months of treatment. Among the long-term treated cohort (390 HIV-1 patients with ≥ 9 years of undetectable viral load), false-negative test results were found in at least 1 HIV confirmatory assay for 2.1% (8/390) of the patients and in a HIV rapid test for 4.9% (19/390). Confirmation assay sensitivities ranged from 98.1% to 99.5%, whereas rapid test sensitivities ranged from 96.2% to 100%. Longer treatment increased nonreactivity of the HIV rapid tests (P = .033). Undetectable viral load decreases the sensitivities of HIV diagnostic tests, and further monitoring of the performance of serological assays is advised.

[The COVID-19 breaker : PCR to the rescue !]

Chronicle of a crisis management at the Clinical Microbiology Laboratory of CHU Liège The SARS-CoV-2 outbreak in December 2019 in China and its expansion across the world and Europe have requested the participation of clinical laboratories as major players in the diagnosis of COVID-19, to perform PCR tests mainly on nasopharyngeal swabs. In Belgium, the first confirmed COVID-19 patient was diagnosed in early February, the first of many, especially travelers returning from winter sports. In order to meet the ever-increasing demands for testing, the Clinical Microbiology Laboratory of the CHU of Liege had to adapt to this situation: firstly, by developing manual PCR tests and then automated solutions, permitting to increase the number of analyzes by ensuring a short turnaround time of results. Then, a system for the communication of results on a large scale has been set up, and finally solutions to deal with the lack of sampling devices have been found. This first wave of the pandemic has also highlighted an unprecedented solidarity within the institution. In this article, we recount the chronology of the management of this unprecedented health crisis within the Clinical Microbiology Laboratory of the CHU of Liege.

Evolution of Drug Interactions With Antiretroviral Medication in People With HIV

Background

Polypharmacy and drug interactions are important issues for HIV-infected individuals. The number and nature of those interactions are continuously evolving with the use of new antiretroviral drugs and the aging of HIV-infected individuals. We aimed to analyze this evolution over time.

Methods

This retrospective cohort study was conducted in the University Hospital of Liège (Belgium). Treatments of HIV-infected outpatients attending Liège University Hospital were collected and analyzed in 2012 and 2016. The University of Liverpool HIV drug interactions database was used to determine drug interactions.

Results

We included 1038 patients in 2016, of whom 78% had 1 comedication. Polypharmacy was seen in 20% of the cohort. Four percent of the patients presented red flag interactions, and 38% had orange flag interactions. Nonantiretroviral (non-ARV) therapeutic classes involved in drug interactions were mostly cardiovascular and central nervous system drugs. They were followed by hormone drugs and dietary supplements for orange flag interactions. Two factors significantly contributed to both red and orange flag interactions: the number of non-ARV comedications and protease inhibitor–based ARV regimens. The proportion of patients with red or orange flag interactions remained stable from 2012 to 2016.

Conclusions

This study highlights the persistence of an alarming number of contraindicated drug interactions and a high prevalence of potential drug interactions over time. Identification, prevention, and management of drug interactions remain a key priority in HIV care.

[Hurdles to HIV cure. Part 2 : ongoing HIV replication despite therapy]

The antiretroviral therapy (ART) has proven its effectiveness in improving the life expectancy of people infected with human immunodeficiency virus (HIV). Based on the inhibition of HIV replication, ART ensures the reduction of plasma viral load to undetectable levels on long-term. Unfortunately, once ART is interrupted, the viral load rises up. Consequently, the therapy remains not curative. The reasons for this failure lie in the presence of latent reservoirs of the virus and/or the presence of ongoing replication, responsible for the persistence of the virus. This ongoing replication despite ongoing therapy has been demonstrated in sanctuary sites where the penetration of antiretroviral drugs is suboptimal. Moreover, some treatment intensification studies, mostly through addition of an integrase inhibitor, transiently resulted in increases in HIV replication by-products, highlighting that such strategies could reduce ongoing replication. Although the debate is still open, confirming the presence of this ongoing replication and finding strategies to eliminate it would be part of the key to a cure for HIV.

[Hurdles to HIV cure. Part 1 : the latent reservoirs]

The human immunodeficiency virus (HIV), responsible for acquired immunodeficiency syndrome or AIDS, is a major public health problem. In Belgium, 2 to 3 new cases are diagnosed every day. Since the advent of combined antiretroviral treatments in 1996, the life expectancy and quality of life of infected patients have greatly improved. However, to date there is no cure for HIV. Individuals infected with HIV must remain on antiretroviral treatment for life. One of the reasons for the difficulty in finding a cure for HIV is that the virus can remain in a latent form, i.e. dormant, in some of the cells it infects. These latent reservoirs are not recognized by the immune system and can reactivate and thus restart the infection if the patient stops the treatment. These latent reservoirs are therefore a major obstacle to cure HIV and a great deal of research is being conducted by the scientific community to find an eradication strategy. In this article, we will present the different characteristics of these latent reservoirs and the different strategies put in place to identify and eliminate them.

Impact of coronavirus pandemic and containment measures on HIV diagnosis

During the last months and following the implementation of containment measures in the context of coronavirus disease 2019 (COVID-19) pandemic, the number of new human immunodeficiency virus (HIV) diagnoses radically decreased in Liege AIDS Reference Center, Belgium. The number of HIV screening tests has also dramatically dropped down to an unprecedented level. This decline of HIV diagnosis is caused by missed diagnoses of individuals infected before the establishment of such measures and to the reduction of high-risk sexual behaviours during the COVID-19 pandemic.

Exploring HIV-1 Transmission Dynamics by Combining Phylogenetic Analysis and Infection Timing

HIV-1 pol sequences obtained through baseline drug resistance testing of patients newly diagnosed between 2013 and 2017 were analyzed for genetic similarity. For 927 patients the information on genetic similarity was combined with demographic data and with information on the recency of infection. Overall, 48.3% of the patients were genetically linked with 11.4% belonging to a pair and 36.9% involved in a cluster of ≥3 members. The percentage of early diagnosed (≤4 months after infection) was 28.6%. Patients of Belgian origin were more frequently involved in transmission clusters (49.7% compared to 15.3%) and diagnosed earlier (37.4% compared to 12.2%) than patients of Sub-Saharan African origin. Of the infections reported to be locally acquired, 69.5% were linked (14.1% paired and 55.4% in a cluster). Equal parts of early and late diagnosed individuals (59.9% and 52.4%, respectively) were involved in clusters. The identification of a genetically linked individual for the majority of locally infected patients suggests a high rate of diagnosis in this population. Diagnosis however is often delayed for >4 months after infection increasing the opportunities for onward transmission. Prevention of local infection should focus on earlier diagnosis and protection of the still uninfected members of sexual networks with human immunodeficiency virus (HIV)-infected members.

Distribution of HCV genotypes in Belgium from 2008 to 2015

Background

The knowledge of circulating HCV genotypes and subtypes in a country is crucial to guide antiviral therapy and to understand local epidemiology. Studies investigating circulating HCV genotypes and their trends have been conducted in Belgium. However they are outdated, lack nationwide representativeness or were not conducted in the general population.

Methods

In order to determine the distribution of different circulating HCV genotypes in Belgium, we conducted a multicentre study with all the 19 Belgian laboratories performing reimbursed HCV genotyping assays. Available genotype and subtype data were collected for the period from 2008 till 2015. Furthermore, a limited number of other variables were collected: some demographic characteristics from the patients and the laboratory technique used for the determination of the HCV genotype.

Results

For the study period, 11,033 unique records collected by the participating laboratories were used for further investigation.

HCV genotype 1 was the most prevalent (53.6%) genotype in Belgium, with G1a and G1b representing 19.7% and 31.6%, respectively. Genotype 3 was the next most prevalent (22.0%). Further, genotype 4, 2, and 5 were responsible for respectively 16.1%, 6.2%, and 1.9% of HCV infections. Genotype 6 and 7 comprise the remaining <1%. Throughout the years, a stable distribution was observed for most genotypes. Only for genotype 5, a decrease as a function of the year of analysis was observed, with respectively 3.6% for 2008, 2.3% for 2009 and 1.6% for the remaining years.

The overall M:F ratio was 1.59 and was mainly driven by the high M:F ratio of 3.03 for patients infected with genotype 3. Patients infected with genotype 3 are also younger (mean age 41.7 years) than patients infected with other genotypes (mean age above 50 years for all genotypes). The patients for whom a genotyping assay was performed in 2008 were younger than those from 2015.

Geographical distribution demonstrates that an important number of genotyped HCV patients live outside the Belgian metropolitan cities.

Conclusion

This national monitoring study allowed a clear and objective view of the circulating HCV genotypes in Belgium and will help health authorities in the establishment of cost effectiveness determinations before implementation of new treatment strategies.

This baseline characterization of the circulating genotypes is indispensable for a continuous surveillance, especially for the investigation of the possible impact of migration from endemic regions and prior to the increasing use of highly potent direct-acting antiviral (DAA) agents.

Cameron lesions: A still overlooked diagnosis. Case report and systematic review of literature

Cameron lesions are erosive-ulcerative alterations of gastric mucosa occurring in patients with large hiatal hernia, potentially causing gastrointestinal bleeding and iron deficiency anaemia. Diagnosis may be challenging, and not infrequently erosions are overlooked at endoscopy, so that repeated and unnecessary diagnostic procedures are performed, particularly in those patients with chronic anaemia. We described two peculiar cases of patients with iron deficiency anaemia in whom Cameron lesions were either overlooked or misinterpreted. By reviewing data of 22publications reporting endoscopic and clinical data of 140patients, we noted a large prevalence of females (75%). The most frequent presenting symptoms were anaemia (62%) and overt gastrointestinal bleeding (36%). Noteworthy, as many as 69% of patients underwent one or more previous upper endoscopy before diagnosis of Cameron lesion was achieved. Patients were mainly treated with proton pump inhibitor (PPI) therapy and iron supplementation. Moreover, endoscopic haemostasis was performed in 10% of case, blood transfusion was required in one third of cases, and a similar quote of patients underwent a surgical approach for hiatal hernia repair. The observation that as many as 60% patients were already receiving standard PPI therapy when diagnosis was performed would suggest that either long-term treatment with adequate dose PPI or surgical approach for hiatal hernia repair is required. In conclusion, Cameron lesion is still an overlooked diagnosis in patients with iron deficiency anaemia in whom a 5-9.2% prevalence has been reported.

Impact of primary antibiotic resistance on the effectiveness of sequential therapy for Helicobacter pylori infection: lessons from a 5-year study on a large number of strains

BACKGROUND

The increasing prevalence of strains resistant to antimicrobial agents is a critical issue in the management of Helicobacter pylori (H. pylori) infection.

AIMS

(1) To evaluate the prevalence of primary resistance to clarithromycin, metronidazole and levofloxacin (2) to assess the effectiveness of sequential therapy on resistant strains (3) to identify the minimum number of subjects to enrol for evaluating the effectiveness of an eradication regimen in patients harbouring resistant strains.

METHODS

Consecutive 1682 treatment naïve H. pylori-positive patients referred for upper GI endoscopy between 2010 and 2015 were studied and resistances assessed by E-test. Sequential therapy was offered, effectiveness evaluated and analysed.

RESULTS

H. pylori-primary resistance to antimicrobials tested was high, and increased between 2010 and 2015. Eradication rates were (estimates and 95% CIs): 97.3% (95.6-98.4) in strains susceptible to clarithromycin and metronidazole; 96.1% (91.7-98.2) in strains resistant to metronidazole but susceptible to clarithromycin; 93.4% (88.2-96.4) in strains resistant to clarithromycin but susceptible to metronidazole; 83.1% (77.7-87.3) in strains resistant to clarithromycin and metronidazole. For any treatment with a 75%-85% eradication rate, some 98-144 patients with resistant strains need to be studied to get reliable information on effectiveness in these patients.

CONCLUSIONS

H. pylori-primary resistance is increasing and represents the most critical factor affecting effectiveness. Sequential therapy eradicated 83% of strains resistant to clarithromycin and metronidazole. Reliable estimates of the effectiveness of a given regimen in patients harbouring resistant strains can be obtained only by assessing a large number of strains.

Decision tree for accurate infection timing in individuals newly diagnosed with HIV-1 infection

Background

There is today no gold standard method to accurately define the time passed since infection at HIV diagnosis. Infection timing and incidence measurement is however essential to better monitor the dynamics of local epidemics and the effect of prevention initiatives.

Methods

Three methods for infection timing were evaluated using 237 serial samples from documented seroconversions and 566 cross sectional samples from newly diagnosed patients: identification of antibodies against the HIV p31 protein in INNO-LIA, SediaTM BED CEIA and SediaTM LAg-Avidity EIA. A multi-assay decision tree for infection timing was developed.

Results

Clear differences in recency window between BED CEIA, LAg-Avidity EIA and p31 antibody presence were observed with a switch from recent to long term infection a median of 169.5, 108.0 and 64.5 days after collection of the pre-seroconversion sample respectively. BED showed high reliability for identification of long term infections while LAg-Avidity is highly accurate for identification of recent infections. Using BED as initial assay to identify the long term infections and LAg-Avidity as a confirmatory assay for those classified as recent infection by BED, explores the strengths of both while reduces the workload. The short recency window of p31 antibodies allows to discriminate very early from early infections based on this marker. BED recent infection results not confirmed by LAg-Avidity are considered to reflect a period more distant from the infection time. False recency predictions in this group can be minimized by elimination of patients with a CD4 count of less than 100 cells/mm3 or without no p31 antibodies. For 566 cross sectional sample the outcome of the decision tree confirmed the infection timing based on the results of all 3 markers but reduced the overall cost from 13.2 USD to 5.2 USD per sample.

Conclusions

A step-wise multi assay decision tree allows accurate timing of the HIV infection at diagnosis at affordable effort and cost and can be an important new tool in studies analyzing the dynamics of local epidemics or the effects of prevention strategies.

Virological response, HIV-1 drug resistance mutations and genetic diversity among patients on first-line antiretroviral therapy in N'Djamena, Chad: findings from a cross-sectional study

Background

The national antiretroviral therapy in the Republic of Chad provides free of charge antiretroviral regimens and therapeutic monitoring for patients receiving antiretroviral therapy nationwide. For a successful programmatic uptake, these efforts merit to be supported by thorough assessments of antiretroviral therapy response and HIV-1 drug resistance surveillance, especially with risks of cross-resistance due to the gradual stavudine phasing out in such national settings. We therefore evaluated the virological response to antiretroviral therapy, HIV-1 drug resistance emergence and circulating HIV-1 clades in a Chad context. A cross-sectional and prospective study was conducted among 116 patients (41 [δ ± 6.87] years, 59% female) receiving first-line antiretroviral therapy for ≥ 6 months in Ndjamena, Chad, in 2011–2012, enrolled consecutively. To ensure accuracy, plasma viral load was concomitantly measured using Abbott Real-Time and Cobas AmpliPrep/TaqMan (v2.0), and virological failure defined as ≥ 1000 HIV-1 RNA copies/ml. Plasma from patients experiencing virological failure were processed for sequencing of HIV-1 protease-reverse transcriptase using the ANRS-AC.11 resistance testing protocol; drug resistant mutations were interpreted using the ANRS-AC11 algorithm; and phylogenetic analysis was performed using MEGA.v.6.

Results

Majority of patients was receiving zidovudine plus lamivudine plus nevirapine (46%), stavudine plus lamivudine plus nevirapine (41%) and tenofovir plus emtricitabine plus efavirenz (11%), for a median time-on-treatment of 5 [IQR 4–7] years. The rate of virological failure was 43% (50/116), with 86% (43/50) sequencing performance. Overall, 32% (37/116) patients presented ≥ one major drug resistant mutation(s), with 29% (34/116) to nucleos(t)ide reverse transcriptase inhibitors (67% [29/43] M184V/I, 30% [13/43] T215Y/F, 19% [8/43] V75A/F/I/L/M, 9% [4/43] K70P/R/W, 9% [4/43] K219E/N/Q and 5% [2/43] A62V); 86% (37/43) to non-nulceos(t)ide reverse transcriptase inhibitors (30% [13/43] K103N/S/E, 26% [11/43] Y181C/V/F/L, 2% [1/43] L100I, 2% [1/43] F227L, 2% [1/43] P225H); and 2% (1/43) to protease inhibitors (M46I, I54V, V82S). Six HIV-1 subtypes were found: 30% circulating recombinant form (CRF02_AG), 30% J, 16% G, 9% A, 9% D, 5% F.

Conclusions

In Chad, almost half of patients are failing first-line antiretroviral therapy after 5 years, with considerable drug resistant mutations at failure. Absence of K65R supports the use of tenofovir-containing regimens as preferred first-line and as suitable drug for second-line combinations, in this setting with significant HIV-1 genetic diversity.

Electronic supplementary material

The online version of this article (10.1186/s13104-017-2893-1) contains supplementary material, which is available to authorized users.

Transmission of HIV Drug Resistance and the Predicted Effect on Current First-line Regimens in Europe

Transmitted human immunodeficiency virus drug resistance in Europe is stable at around 8%. The impact of baseline mutation patterns on susceptibility to antiretroviral drugs should be addressed using clinical guidelines. The impact on baseline susceptibility is largest for nonnucleoside reverse transcriptase inhibitors.

Background. Numerous studies have shown that baseline drug resistance patterns may influence the outcome of antiretroviral therapy. Therefore, guidelines recommend drug resistance testing to guide the choice of initial regimen. In addition to optimizing individual patient management, these baseline resistance data enable transmitted drug resistance (TDR) to be surveyed for public health purposes. The SPREAD program systematically collects data to gain insight into TDR occurring in Europe since 2001.

Methods. Demographic, clinical, and virological data from 4140 antiretroviral-naive human immunodeficiency virus (HIV)–infected individuals from 26 countries who were newly diagnosed between 2008 and 2010 were analyzed. Evidence of TDR was defined using the WHO list for surveillance of drug resistance mutations. Prevalence of TDR was assessed over time by comparing the results to SPREAD data from 2002 to 2007. Baseline susceptibility to antiretroviral drugs was predicted using the Stanford HIVdb program version 7.0.

Results. The overall prevalence of TDR did not change significantly over time and was 8.3% (95% confidence interval, 7.2%–9.5%) in 2008–2010. The most frequent indicators of TDR were nucleoside reverse transcriptase inhibitor (NRTI) mutations (4.5%), followed by nonnucleoside reverse transcriptase inhibitor (NNRTI) mutations (2.9%) and protease inhibitor mutations (2.0%). Baseline mutations were most predictive of reduced susceptibility to initial NNRTI-based regimens: 4.5% and 6.5% of patient isolates were predicted to have resistance to regimens containing efavirenz or rilpivirine, respectively, independent of current NRTI backbones.

Conclusions. Although TDR was highest for NRTIs, the impact of baseline drug resistance patterns on susceptibility was largest for NNRTIs. The prevalence of TDR assessed by epidemiological surveys does not clearly indicate to what degree susceptibility to different drug classes is affected.

Late presentation to HIV testing is overestimated when based on the consensus definition

Objectives

In 2011, a consensus was reached defining “late presenters” (LPs) as individuals presenting for care with a CD4 count < 350 cells/μL or with an AIDS‐defining event, regardless of CD4 count. However, a transient low CD4 count is not uncommon in recent infections. The objective of this study was to investigate how measurements of late presentation change if the clinical stage at the time of diagnosis is taken into account.

Methods

Case surveillance data for newly diagnosed patients in Belgium in 1998–2012 were analysed, including CD4 count at diagnosis, the presence of AIDS‐defining events, and recent infections (< 6 months) as reported by clinicians in the case of acute illness or a recent negative test. First, proportions of LPs were calculated according to the consensus definition. Secondly, LPs were reclassified as “nonlate” if infections were reported as recent.

Results

A total of 7949 HIV diagnoses were included in the study. Recent infections were increasingly reported over time, accounting for 8.2% of new infections in 1998 and 37.5% in 2012. The consideration of clinical stage significantly modified the proportion of LPs: 18.2% of men who have sex with men (MSM) diagnosed in 2012 would be classified as LPs instead of 30.9% using the consensus definition (P < 0.001). The proportion of patients misclassified as LPs increased significantly over time: 5% in MSM in 1998 vs. 41% in 2012.

Conclusions

This study suggests that low CD4 counts in recent infections may lead to overestimation of late presentation when applying the consensus definition. The impact of transient CD4 count on late presentation estimates should be assessed and, if relevant, the introduction of clinical stage in the definition of late presentation should be considered.

Minocycline attenuates HIV-1 infection and suppresses chronic immune activation in humanized NOD/LtsZ-scidIL-2Rγ(null) mice

More than a quarter of a century of research has established chronic immune activation and dysfunctional T cells as central features of chronic HIV infection and subsequent immunodeficiency. Consequently, the search for a new immunomodulatory therapy that could reduce immune activation and improve T-cell function has been increased. However, the lack of small animal models for in vivo HIV study has hampered progress. In the current study, we have investigated a model of cord blood haematopoietic progenitor cells (CB-HPCs) -transplanted humanized NOD/LtsZ-scidIL-2Rγ(null) mice in which progression of HIV infection is associated with widespread chronic immune activation and inflammation. Indeed, HIV infection in humanized NSG mice caused up-regulation of several T-cell immune activation markers such as CD38, HLA-DR, CD69 and co-receptor CCR5. T-cell exhaustion markers PD-1 and CTLA-4 were found to be significantly up-regulated on T cells. Moreover, increased plasmatic levels of lipopolysaccharide, sCD14 and interleukin-10 were also observed in infected mice. Treatment with minocycline resulted in a significant decrease of expression of cellular and plasma immune activation markers, inhibition of HIV replication and improved T-cell counts in HIV-infected humanized NSG mice. The study demonstrates that minocycline could be an effective, low-cost adjunctive treatment to regulate chronic immune activation and replication of HIV.

The RIAD peptidomimetic inhibits HIV-1 replication in humanized NSG mice

BACKGROUND

Increased intracellular concentration of cyclic AMP (cAMP) in T cells is associated with various immunodeficiency conditions including human immunodeficiency virus (HIV) infection. Several reports indicate a critical role of activated protein kinase A (PKA) in the susceptibility of cells to HIV infection. We have used a cell permeable, stable peptidomimetic version (P3) of the RI-anchoring disruptor (RIAD), which prevents PKA interaction with A-kinase-anchoring proteins (AKAPs). It is known that RIAD peptide abrogates effects of localized cAMP signalling through anchored type I PKA in lymphocytes and prevents murine AIDS (MAIDS) infection when expressed as a transgene in mice.

METHODS AND RESULTS

In vitro HIV-infected human peripheral blood mononuclear cells (PBMCs) show reduced levels of p24 and intracellular cAMP in T cells when treated with RIAD peptidomimetic (RIAD-P3). Humanized NOD/SCID/IL2γnull (NSG) mice infected with HIV-1 JRCSF and treated with RIAD-P3 (3·5 mg) once every 2 weeks showed significantly reduced levels of viral load at +28, +42 and +56 days and increased CD4 numbers at +56 days after the start of treatment. RIAD-P3-treated humanized mice had lower levels of intracellular cAMP in T cells sorted from splenocytes.

CONCLUSIONS

Treatment with RIAD-P3 limits HIV-1 viral replication and stabilizes CD4 levels by mechanisms involving cAMP/PKA-I pathway in human PBMCs and humanized NSG mice.

Epidemiological profiles of human immunodeficiency virus and hepatitis C virus infections in Malian women: Risk factors and relevance of disparities

AIM: To document the epidemiologic patterns and risk factors of human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infections in Mali in order to develop prevention means for both diseases.

METHODS: Two prospective studies were conducted in Bamako in 2009 among 1000 pregnant women (i.e., young women) who consulted six reference health centers, and in 2010, among 231 older women who attended general practice in two hospitals. Antibody tests and molecular analysis (performed only for HCV) were used to quantify the frequencies of both infections. The data were collected from patients recruited through a questionnaire. Transmission risk factors of both diseases were identified by univariate and multivariate analysis.

RESULTS: HCV seroprevalence was 0.2% for young and 6.5% for older women. HIV prevalence was similar in both populations (4.1% vs 6.1%). In older women, the analysis of risk factors highlighted an association between HCV infection and episodes of hospitalization (P < 0.01). The study did not show an association between HIV infection and the variables such as hospitalization, transfusion, tattoo, dental care, and endoscopy. A significant decrease of HIV seroprevalence was detected in young women who used condoms for contraception more than for other purposes (P < 0.01). By contrast, HIV seroprevalence was significantly increased in young women using condoms mainly to prevent sexual infections rather than for contraception (P < 0.01). No HCV/HIV coinfection was detected in our study.

CONCLUSION: Risk factors and epidemiologic data of HIV and HCV as well as the absence of co-infection strongly suggest epidemiological disparities between these diseases.

Prevalence of HIV and HCV infections in two populations of Malian women and serological assays performances

AIM

To estimate the prevalence of human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infections in women in Mali and to evaluate the performance of serological assays.

METHODS

Two prospective studies were conducted in 2009 and 2010 in Mali. They concerned first, 1000 pregnant women attending six reference health centers in Bamako (Malian capital) between May 26 and June 16, 2009; and secondly, 231 women over 50 years who consulted general practitioners of two hospitals in Bamako between October 25 and December 24, 2010. Blood samples were collected and kept frozen in good condition before analysis. All samples depicted as positive using HIV/HCV enzyme immuno-assay screening assays were submitted to confirmation analysis. Molecular markers of HCV were characterized.

RESULTS

The seroprevalence of HIV and HCV in the population of pregnant women was 4.1% and 0.2% respectively. Among older women the seroprevalence was higher and similar for HIV and HCV (6.1% vs 6.5%). The anti-HIV prevalence was not different in young and older women (4.1% vs 6.1%). In contrast, the anti-HCV prevalence was higher in older compared to younger women (6.5% vs 0.2%, P < 0.01). Of 2 pregnant women who were HCV seropositive, only one was polymerase chain reaction (PCR) reactive and infected by genotype 2, with a viral load of 1600 IU/mL. Regarding older women who were HCV seropositive, 13 out of 15 were PCR reactive, infected by genotype 1 or 2. Globally HCV genotype 2 was predominant. The positive predictive value (PPV) measured with VIKIA HIV test in young women was 100% therefore significantly higher than the 87.5% measured in older women (P < 0.05). Conversely, the PPV measured with Monolisa HCV assay in older women was 88.2% and higher than the 14.3% measured in younger women (P < 0.01).

CONCLUSION

Whereas HIV prevalence was similar in both subpopulations HCV was more frequent among older women (P < 0.01). The PPV of screening assays varied with the age of the subjects.

Review article: bismuth-based therapy for Helicobacter pylori eradication in children

BACKGROUND

Because of the decrease in the Helicobacter pylori eradication rate after standard triple therapy with a proton pump inhibitor and two antibiotics, bismuth-based therapy has recently been recommended as alternate first-line regimen in children.

AIM

To comprehensively review the clinical, pharmacologic and microbiologic properties of bismuth salts, and to summarise the evidence for the therapeutic efficacy of bismuth-based therapy for H. pylori eradication in children.

METHODS

Bibliographical searches were performed in MEDLINE. Results on the efficacy of bismuth-containing regimens on H. pylori eradication were combined using the inverse variance method.

RESULTS

Bismuth monotherapy showed a very low efficacy. Overall, the mean eradication rate with bismuth-based dual therapy was 68% (95% CI, 60-76%) (intention-to-treat analysis-ITT) and 73% (95% CI, 64-81%) (per protocol-PP). In case series, the overall percentages of children with successful eradication for triple therapy containing bismuth were 82% (95% CI, 76-88%) and 86% (95% CI, 80-92%) according to ITT and PP respectively. In comparative studies, H. pylori eradication rates ranged between 69% and 85% according to ITT and between 74% and 96% PP. Side effects included dark stools, urine discoloration, black tongue, burning tongue, and marked darkness of the gums.

CONCLUSIONS

The evidence in favour of bismuth compounds for treating infected children is still not clear. Well-designed, randomised, multi-centre studies of H. pylori eradication trials in children comparing bismuth-based triple therapy with the best available recommended first-line therapies are needed. The evidence obtained from audited case series that produce an eradication rate of >95% on PP analysis should also be considered.

Hepatitis C of genotype 2: the role of medical invasive exams

BACKGROUND AND AIM

Hepatitis C virus genotype 2 is the third in order of frequency in Belgium. The aim of this study was to better define the genotype 2 carriers' epidemiology characteristics.

METHODS

In a database comprising 1726 viremic hepatitis C virus patient from the south part of Belgium, the files of 98 genotype 2 carriers were reviewed.

RESULTS

There was a strong association between genotype 2 and the mode of transmission. The rate of contamination by invasive medical exams was very high (23%), and statistically different from the one of the others genotypes. Eligibility for antiviral therapies and the rate of sustained viral response were high.

CONCLUSION

HCV genotype 2 was highly associated with transmission by invasive medical exams.

Comparison of phenotypic and genotypic tropism determination in triple-class-experienced HIV patients eligible for maraviroc treatment

Background

Determination of HIV-1 tropism is a pre-requisite to the use of CCR5 antagonists. This study evaluated the potential of population genotypic tropism tests (GTTs) in clinical practice, and the correlation with phenotypic tropism tests (PTTs) in patients accessing routine HIV care.

Methods

Forty-nine consecutive plasma samples for which an original Trofile^TM assay was performed were obtained from triple-class-experienced patients in need of a therapy change. Viral tropism was defined as the consensus of three or more tropism calls obtained from the combination of two independent population PTT assays (Trofile Biosciences, San Francisco, CA, USA, and Virco, Beerse, Belgium), population GTTs and GTTs based on ultra-deep sequencing. If no consensus was reached, a clonal PTT was performed in order to finalize the tropism call. This two-step approach allowed the definition of a reference tropism call.

Results

According to the reference tropism result, 35/49 samples were CCR5 tropic (R5) (patients eligible for maraviroc treatment) and 14/49 were assigned as non-R5 tropic. The non-R5 samples [patients not eligible for maraviroc treatment according to the FDA/European Medicines Agency (EMEA) label] group included both the CXCR4 (X4) samples and the dual and mixed CCR5/CXCR4 (R5/X4) samples. Compared with Trofile^TM population PTTs, population GTTs showed a higher sensitivity (97%) and a higher negative predictive value (91%), but almost equal specificity and an equal positive predictive value.

Conclusions

In line with recent reports from clinical trial data, our data support the use of population genotypic tropism testing as a tool for tropism determination before the start of maraviroc.

HIV-1 V3 envelope deep sequencing for clinical plasma specimens failing in phenotypic tropism assays

Background

HIV-1 infected patients for whom standard gp160 phenotypic tropism testing failed are currently excluded from co-receptor antagonist treatment. To provide patients with maximal treatment options, massively parallel sequencing of the envelope V3 domain, in combination with tropism prediction tools, was evaluated as an alternative tropism determination strategy. Plasma samples from twelve HIV-1 infected individuals with failing phenotyping results were available. The samples were submitted to massive parallel sequencing and to confirmatory recombinant phenotyping using a fraction of the gp120 domain.

Results

A cut-off for sequence reads interpretation of 5 to10 times the sequencing error rate (0.2%) was implemented. On average, each sample contained 7 different V3 haplotypes. V3 haplotypes were submitted to tropism prediction algorithms, and 4/14 samples returned with presence of a dual/mixed (D/M) tropic virus, respectively at 3%, 10%, 11%, and 95% of the viral quasispecies. V3 tropism prediction was confirmed by gp120 phenotyping, except for two out of 4 D/M predicted viruses (with 3 and 95%) which were phenotypically R5-tropic. In the first case, the result was discordant due to the limit of detection for the phenotyping technology, while in the latter case the prediction algorithms were not computing the viral tropism correctly.

Conclusions

Although only demonstrated on a limited set of samples, the potential of the combined use of "deep sequencing + prediction algorithms" in cases where routine gp160 phenotype testing cannot be employed was illustrated. While good concordance was observed between gp120 phenotyping and prediction of R5-tropic virus, the results suggest that accurate prediction of X4-tropic virus would require further algorithm development.

Accuracy of a new ultrafast rapid urease test to diagnose Helicobacter pylori infection in 1000 consecutive dyspeptic patients

BACKGROUND

Rapid diagnostic tools for Helicobacter pylori are important in endoscopy.

AIMS

To assess the accuracy of a new 5 min rapid urease test (UFT300, ABS Srl, Cernusco sul Naviglio, Milan, Italy) and to compare it with the 1 h Pyloritek (Serim Laboratories, Elkhart, IN, USA) and the 24 h CLO test (Kimberly-Clark Ballard Medical Products, Roswell, GA, USA).

METHOD

Consecutive dyspeptic patients referred to our unit for endoscopy were prospectively studied. All patients underwent a (13)C-urea-breath test, histology and the UFT300 (ABS Srl; Cernusco sul Naviglio, Milan, Italy). In a sub-set of patients (n = 375), two additional RUTs were performed. Patients were deemed infected if both (13)C-UBT and histology were positive. RUTs were read at 1, 5, and 60 min.

RESULTS

Of 1000 enrolled patients 45.3% were infected with H. pylori. The sensitivity of the UFT 300 was 90.3%, 94.5% and 96.2% at 1, 5 and 60 min respectively (specificity 100%). The Pyloritek and the UFT were comparable, but the CLO test was not reliable at 5 and 60 min.

CONCLUSION

The UFT 300 test is comparable to the Pyloritek test, but the CLO test is significantly less sensitive at early time points. Reading test results at 1 min may increase false negative results, thereby decreasing sensitivity.

Synergistic activation of HIV-1 expression by deacetylase inhibitors and prostratin: implications for treatment of latent infection

The persistence of transcriptionally silent but replication-competent HIV-1 reservoirs in Highly Active Anti-Retroviral Therapy (HAART)-treated infected individuals, represents a major hurdle to virus eradication. Activation of HIV-1 gene expression in these cells together with an efficient HAART has been proposed as an adjuvant therapy aimed at decreasing the pool of latent viral reservoirs. Using the latently-infected U1 monocytic cell line and latently-infected J-Lat T-cell clones, we here demonstrated a strong synergistic activation of HIV-1 production by clinically used histone deacetylase inhibitors (HDACIs) combined with prostratin, a non-tumor-promoting nuclear factor (NF)- κB inducer. In J-Lat cells, we showed that this synergism was due, at least partially, to the synergistic recruitment of unresponsive cells into the expressing cell population. A combination of prostratin+HDACI synergistically activated the 5′ Long Terminal Repeat (5'LTR) from HIV-1 Major group subtypes representing the most prevalent viral genetic forms, as shown by transient transfection reporter assays. Mechanistically, HDACIs increased prostratin-induced DNA-binding activity of nuclear NF-κB and degradation of cytoplasmic NF-κB inhibitor, IκBα . Moreover, the combined treatment prostratin+HDACI caused a more pronounced nucleosomal remodeling in the U1 viral promoter region than the treatments with the compounds alone. This more pronounced remodeling correlated with a synergistic reactivation of HIV-1 transcription following the combined treatment prostratin+HDACI, as demonstrated by measuring recruitment of RNA polymerase II to the 5'LTR and both initiated and elongated transcripts. The physiological relevance of the prostratin+HDACI synergism was shown in CD8⁺-depleted peripheral blood mononuclear cells from HAART-treated patients with undetectable viral load. Moreover, this combined treatment reactivated viral replication in resting CD4⁺ T cells isolated from similar patients. Our results suggest that combinations of different kinds of proviral activators may have important implications for reducing the size of latent HIV-1 reservoirs in HAART-treated patients.

[A fixed dose anti-HIV combination for the poor? Triomune]

Despite a relative global stabilization of its incidence, HIV infection remains a major threat for public health, principally in Africa where it concerns more than 22 million people and constitutes the first cause of death on the continent. To face the emergency of the HIV/AIDS epidemics on the African continent, the primary goal is to make available to all patients free and efficient antiretroviral medications. Such a goal cannot be dissociated from large scale prevention campaigns. In 2000, Triomune, one of the first fixed dose combinations of three antiretrovirals (stavudine, lamivudine & nevirapine) was launched by the Indian drug company Cipla, specialized in the production of low cost medications. Its convenient pill burden (one pill twice a day) and its very low cost (around 30 US $ per month) make Triomune an appealing solution for the treatment of HIV/AIDS in Africa. Unfortunately, Triomune presents several drawbacks (low genetic barrier, frequent side effects) and one of its constituents is not used in Europe anymore. Other first line treatments are urgently needed.

Duplicate breath testing to confirm eradication of Helicobacter pylori: incremental benefit and cost in 419 patients

BACKGROUND

Current standards for establishing a cure of H. pylori infection require two breath tests taken at least 4 weeks apart, to be negative.

AIM

To determine the incremental cost and accuracy of repeating a urea breath test (UBT) in clinical practice.

METHODS

We identified 419 patients with documented Helicobacter pylori infection who received eradication therapy and then had two breath tests, one 4 weeks and the second at least 8 weeks after the completion of treatment. H. pylori infection was documented at baseline by a positive rapid urease test and histology.

RESULTS

In patients with successful eradication of H. pylori infection (n = 317), the mean +/- standard deviation delta over baseline (DOB) value before treatment was 43 +/- 29 ppm. Following treatment, the mean DOB in cured was 0.56 +/- 2.1 ppm at 1 month and was similar to the value obtained at the second breath (0.68 +/- 1; P = 0.39), which was performed 60 +/- 71 days after the first UBT. In patients remaining infected (n = 102), the mean DOB at baseline was 47 +/- 20 ppm. Four weeks after treatment, the DOB was 40 +/- 32 ppm. The second UBT was performed 94 +/- 72 days after the first and the DOB was significantly greater than the first (47 +/- 28; P = 0.040). There was no discordant result between the first breath test and second breath test. At a cost of 30 euros/breath test, the incremental cost of a second breath test was 12 570 euros in this cohort with no incremental clinical benefit.

CONCLUSIONS

A single UBT, 4 weeks after treatment is as effective as two serial breath tests in confirming H. pylori eradication. The incremental cost of the second breath test is very high with no incremental clinical benefit.

Failure of first-line eradication treatment significantly increases prevalence of antimicrobial-resistant Helicobacter pylori clinical isolates

OBJECTIVES

Helicobacter pylori infection is a major health problem worldwide, and effective eradication of the infection is mandatory. The efficacy of recommended eradication regimens is approximately 70%. To avoid treatment failure and the consequent development of secondary resistance(s), it is important to choose the most appropriate first-line treatment regimen. This choice should also be made based on the knowledge of the antimicrobial resistance peculiar to a given geographical area. We evaluated the prevalence of antimicrobial-resistant H pylori strains isolated from naive patients and from patients with previous unsuccessful treatments.

METHODS

This study examined 109 H pylori-infected subjects (Group 1) who had never received an eradication treatment and 104 H pylori-infected subjects (Group 2) who had failed one or more eradication treatments. Resistance to amoxicillin (AMO), tetracycline (TET), clarithromycin (CLA), metronidazole (MET) and levofloxacin (LEV) was determined using the epsilometer test. The significance of differences was evaluated by the chi2 test.

RESULTS

The prevalence of antimicrobial resistance was 0% versus 3.1% to AMO, 0% versus 2% to TET, 27% versus 41.3% to MET (p<0.05), 18% versus 45.8% to CLA (p<0.05) and 3% versus 14.6% to LEV (p<0.05) in Group 1 vs Group 2, respectively. In Group 2, there was an increased prevalence of H pylori strains resistant to multiple antimicrobials.

CONCLUSIONS

This study confirms the high prevalence of H pylori strains resistant to CLA and MET, and indicates that unsuccessful treatments significantly increase resistance. Choosing eradication regimens other than standard triple therapy as a first-line therapy should be advisable in areas with high primary antimicrobial resistance prevalence.

Prevalence and epidemiology of HIV type 1 drug resistance among newly diagnosed therapy-naive patients in Belgium from 2003 to 2006

This study is the first prospective study to assess the prevalence, epidemiology, and risk factors of HIV-1 drug resistance in newly diagnosed HIV-infected patients in Belgium. In January 2003 it was initiated as part of the pan-European SPREAD program, and continued thereafter for four inclusion rounds until December 2006. Epidemiological, clinical, and behavioral data were collected using a standardized questionnaire and genotypic resistance testing was done on a sample taken within 6 months of diagnosis. Two hundred and eighty-five patients were included. The overall prevalence of transmitted HIV-1 drug resistance in Belgium was 9.5% (27/285, 95% CI: 6.6-13.4). Being infected in Belgium, which largely coincided with harboring a subtype B virus, was found to be significantly associated with transmission of drug resistance. The relatively high rate of baseline resistance might jeopardize the success of first line treatment as more than 1 out of 10 (30/285, 10.5%) viruses did not score as fully susceptible to one of the recommended first-line regimens, i.e., zidovudine, lamivudine, and efavirenz. Our results support the implementation of genotypic resistance testing as a standard of care in all treatment-naive patients in Belgium.

Levofloxacin-based triple therapy for Helicobacter pylori re-treatment: role of bacterial resistance

BACKGROUND

First-line Helicobacter pylori therapy fails in more than 20% of patients. Quadruple therapy is the suggested second-line therapy, but bismuth salts are not anymore available worldwide. This study aimed to assess the efficacy of a levofloxacin-amoxycillin triple therapy as a second-line treatment, and the role of primary levofloxacin resistance.

METHODS

Forty patients, in whom first treatment with either standard 10-day triple or sequential therapy had failed, received 10-day triple therapy with rabeprazole (20mg b.d.), levofloxacin (250mg b.d.), and amoxycillin (1g b.d.). Cure rates were evaluated by the (13)C-urea breath test. Primary levofloxacin resistance was detected by culture.

RESULTS

Bacterial culture was available in 33 (82.5%) out 40 patients, and primary levofloxacin resistance was detected in 10 (30.3%) patients. Overall, 33 of 40 patients accepted to participate in this study, and all returned for follow-up after therapy. Compliance to the therapy was safe except 1 patient only who stopped earlier the treatment due to side effects (oral candidiasis). H. pylori infection was eradicated in 24 patients, accounting for a 72.7% (95% CI: 57-88) eradication rate at both intention-to-treat and per protocol analyses. The eradication rate was higher in patients harbouring levofloxacin-susceptible than resistant strains (75% versus 33.3%; P=0.074).

CONCLUSIONS

The eradication rate achieved by a levofloxacin-based re-treatment seems to be decreasing, and its efficacy is reduced in presence of levofloxacin resistance.

Downregulation of CD94/NKG2A inhibitory receptors on CD8+ T cells in HIV infection is more pronounced in subjects with detected viral load than in their aviraemic counterparts

The CD94/NKG2A heterodimer is a natural killer receptor (NKR), which inhibits cell-mediated cytotoxicity upon interaction with MHC class I gene products. It is expressed by NK cells and by a small fraction of activated CD8+ T lymphocytes. Abnormal upregulation of the CD94/NKG2A inhibitory NKR on cytotoxic T cells (CTLs) could be responsible for a failure of immunosurveillance in cancer or HIV infection. In this study, CD94/NKG2A receptor expression on CD8+ T lymphocytes and NK cells was assessed in 46 HIV-1-infected patients (24 viraemic, 22 aviraemic) and 10 healthy volunteers. The percentage of CD8+ T lymphocytes expressing the CD94/NKG2A inhibitory heterodimer was very significantly decreased in HIV-1-infected patients in comparison with non-infected controls. Within the HIV infected patients, the proportion of CD8+ T lymphocytes and NK cells expressing CD94/NKG2A was higher in subjects with undetectable viral loads in comparison with their viraemic counterparts. No significant difference was detected in the proportion of CD8+ T lymphocytes expressing the activatory CD94/NKG2C heterodimer between the HIV-1 infected patients and the healthy donors, nor between the vireamic and avireamic HIV-1 infected patients. In conclusion, chronic stimulation with HIV antigens in viraemic patients leads to a decreased rather than increased CD94/NKG2A expression on CD8+ T lymphocytes and NK cells.

Primary antibiotic resistance in Helicobacter pylori strains isolated in northern and central Italy

BACKGROUND

Helicobacter pylori resistance to antibiotics is increasing worldwide, and it reduces the efficacy of therapy.

AIM

To assess current primary antibiotic resistance in H. pylori strains isolated in Italy.

METHODS

Between June 2004 and June 2006, H. pylori strains were isolated consecutively in the two participating centres (Bologna, northern Italy; Rome, central Italy) from patients never previously treated for the infection. Isolated strains were tested for primary clarithromycin, metronidazole and levofloxacin resistance using as break point the minimal inhibitory concentration >/=1, >/=8 and >/=1 mg/L for the three antibiotics, respectively.

RESULTS

Overall, 255 H. pylori strains were evaluated. The resistance rate was 16.9% for clarithromycin, 29.4% for metronidazole and 19.1% for levofloxacin. Clarithromycin resistance was significantly higher in non-ulcer dyspepsia than in peptic ulcer patients (19.1% vs. 0%, P = 0.02), metronidazole resistance was higher in foreign than Italian patients (50% vs. 22.9%, P = 0.0004) and levofloxacin resistance was higher in old than younger patients (28.4% vs. 14.4%, P = 0.048). Levofloxacin resistance was also more frequent in those strains with either clarithromycin or metronidazole resistance.

CONCLUSION

A very high rate of primary resistance towards the tested antibiotics was detected in our study.

Primary antibiotic resistance in Helicobacter pylori strains isolated in northern and central Italy

BACKGROUND

Helicobacter pylori resistance to antibiotics is increasing worldwide, and it reduces the efficacy of therapy.

AIM

To assess current primary antibiotic resistance in H. pylori strains isolated in Italy.

METHODS

Between June 2004 and June 2006, H. pylori strains were isolated consecutively in the two participating centres (Bologna, northern Italy; Rome, central Italy) from patients never previously treated for the infection. Isolated strains were tested for primary clarithromycin, metronidazole and levofloxacin resistance using as break point the minimal inhibitory concentration >/=1, >/=8 and >/=1 mg/L for the three antibiotics, respectively.

RESULTS

Overall, 255 H. pylori strains were evaluated. The resistance rate was 16.9% for clarithromycin, 29.4% for metronidazole and 19.1% for levofloxacin. Clarithromycin resistance was significantly higher in non-ulcer dyspepsia than in peptic ulcer patients (19.1% vs. 0%, P = 0.02), metronidazole resistance was higher in foreign than Italian patients (50% vs. 22.9%, P = 0.0004) and levofloxacin resistance was higher in old than younger patients (28.4% vs. 14.4%, P = 0.048). Levofloxacin resistance was also more frequent in those strains with either clarithromycin or metronidazole resistance.

CONCLUSION

A very high rate of primary resistance towards the tested antibiotics was detected in our study.

Meta-analysis: the efficacy of proton pump inhibitors for laryngeal symptoms attributed to gastro-oesophageal reflux disease

BACKGROUND

Many investigators have proposed an association between gastro-oesophageal reflux disease and laryngo-pharyngeal symptoms, suggesting that medical or surgical therapy for reflux may be useful.

AIM

To perform a meta-analysis assessing the effectiveness of medical or surgical therapy for reflux disease in adult patients with laryngeal or pharyngeal symptoms presumed to be due to gastro-oesophageal reflux disease.

METHODS

Randomized controlled trials comparing medical or surgical treatments for gastro-oesophageal reflux disease against placebo were identified by searching MEDLINE (1966-September 2005), EMBASE (1974-September 2005), the CCRCT (until September 2005) and abstracts from gastroenterology and ENT meetings. The relative risks of reporting symptomatic improvement or resolution of symptoms was evaluated using a random-effects model.

RESULTS

Five studies using high-dose proton pump inhibitor as intervention met the inclusion criteria and were included in the meta-analysis. No surgical studies met inclusion criteria. The pooled relative risk was 1.18 (95% confidence interval: 0.81-1.74). There was no heterogeneity between studies but evidence of significant publication bias. Sub-group analysis performed evaluating Jadad scores and symptom type, did not change the relative risk.

CONCLUSIONS

Therapy with a high-dose proton pump inhibitor is no more effective than placebo in producing symptomatic improvement or resolution of laryngo-pharyngeal symptoms. Further studies are necessary to identify the characteristics of patients that may respond to proton pump inhibitor therapy.

[New approaches to the treatment of the HIV-infected patient]

HIV infection remains a major problem of public health in Belgium as well as globally. The number of new diagnosies of HIV infection in Belgium remains between two and three daily. Given the dramatic effect of antiretroviral therapy on the mortality due to HIV infection, the number of patients is constantly increasing. The different problems related to HIV care are also changing. Aging of the patients and chronic exposure to antiretroviral medications have induced new complications. We will present in this brief article several new experimental and clinical approaches in which our centre has participated during the last two years.

HCV genotype 4 in Belgium: three distinct patterns among patients from European and African origin

BACKGROUND

Considered uncommon in western countries some years ago, hepatitis C virus of genotype 4 is now spreading in some areas of Europe. This is assumed to be due to immigration from a region of high prevalence for this genotype and to propagation among drug users. In the south of Belgium, genotype 4 currently accounts for 10% of hepatitis C virus patients and its prevalence is increasing with time.

OBJECTIVE

To better define the genotype 4 carriers' characteristics.

METHODS

In a database comprising 1726 viraemic hepatitis C virus patients, the files of 85 genotype 4 carriers were reviewed.

RESULTS

Beside the African (58%) and European drug user (15%) subgroups classically described, a third subgroup consisting of European nondrug users (26%) was identified as peculiar: these patients were older, had been mostly contaminated sporadically, presented a great diversity of subtypes, and were mainly of Italian origin. In this subgroup, contamination was supposed to be ancient, having occurred probably in Italy before immigration into Belgium. By contrast, European drug users were infected with only two subtypes (4c/4d and 4), an observation in favour of recent spread. Africans had a great diversity of subtypes, were young, and were mostly contaminated sporadically in their home countries. Despite their epidemiological differences, the clinical management, and in particular the rates of eligibility for treatment, were similar for these three groups.

CONCLUSIONS

Three different patterns of genotype 4 carriers were observed, corresponding to three different spreading profiles. They did not induce, however, different clinical management.