Helicobacter pylori infection rates in dyspeptic Serbian HIV-infected patients compared to HIV-negative controls.

Helicobacter pylori infection does not belong to the spectrum of opportunistic infections in people living with HIV (PLHIV). To evaluate the Helicobacter pylori infection prevalence rate trends in HIV co-infected individuals in comparison to the HIV-negative population, we compared histopathological findings of H. pylori positive gastritis (gastritis topography and histopathology) between 303 PLHIV and 2642 HIV-negative patients who underwent esophagogastroduodenoscopy (EGD) between 1993 and 2014 due to dyspeptic symptoms. The prevalence of H. pylori infection was significantly higher in HIV-negative controls than in PLHIV (50.2% vs. 28.1%). A significantly positive linear trend of H. pylori co-infection in PLHIV was revealed in the observed period (b = 0.030, SE = 0.011, p = 0.013), while this trend was significantly negative in HIV-negative patients (b = - 0.027, SE = 0.003, p < 0.001). Patients with HIV/H. pylori co-infection had significantly higher CD4+ T cell counts and more often had undetectable HIV viremia, due to successful anti-retroviral therapy (ART). Stomach histopathological findings differed between HIV co-infected and H. pylori mono-infected patients. Our findings confirm that the ART has changed the progression of HIV infection, leading to a significant increase in the prevalence of H. pylori infection in dyspeptic PLHIV over time. Our data also suggests that a functional immune system may be needed for H. pylori-induced human gastric mucosa inflammation.

Exploring Evolutionary and Transmission Dynamics of HIV Epidemic in Serbia: Bridging Socio-Demographic With Phylogenetic Approach.

Previous molecular studies of Serbian HIV epidemic identified the dominance of subtype B and presence of clusters related HIV-1 transmission, in particular among men who have sex with men (MSM). In order to get a deeper understanding of the complexities of HIV sub-epidemics in Serbia, epidemic trends, temporal origin and phylodynamic characteristics in general population and subpopulations were analyzed by means of mathematical modeling, phylogenetic analysis and latent class analysis (LCA). Fitting of the logistic curve of trends for a cumulative annual number of new HIV cases in 1984-2016, in general population and MSM transmission group, was performed. Both datasets fitted the logistic growth model, showing the early exponential phase of the growth curve. According to the suggested model, in the year 2030, the number of newly diagnosed HIV cases in Serbia will continue to grow, in particular in the MSM transmission group. Further, a detailed phylogenetic analysis was performed on 385 sequences from the period 1997-2015. Identification of transmission clusters, estimation of population growth (Ne), of the effective reproductive number (Re) and time of the most recent common ancestor (tMRCA) were estimated employing Bayesian and maximum likelihood methods. A substantial proportion of 53% of subtype B sequences was found within transmission clusters/network. Phylodynamic analysis revealed Re over one during the whole period investigated, with the steepest slopes and a recent tMRCA for MSM transmission group subtype B clades, in line with a growing trend in the number of transmissions in years approaching the end of the study period. Contrary, heterosexual clades in both studied subtypes - B and C - showed modest growth and stagnation. LCA analysis identified five latent classes, with transmission clusters dominantly present in 2/5 classes, linked to MSM transmission living in the capital city and with the high prevalence of co-infection with HBV and/or other STIs.Presented findings imply that HIV epidemic in Serbia is still in the exponential growth phase, in particular, related to the MSM transmission, with estimated steep growth curve until 2030. The obtained results imply that an average new HIV patient in Serbia is a young man with concomitant sexually transmitted infection.

Successful treatment of chronic hepatitis C in a hemodialysis.

We present the first case of successful direct acting antiviral therapy of chronic hepatitis C in a hemodialysis patient in Serbia. The patient infected with genotype 1a has been successfully treated with Paritaprevir/Ritonavir/Ombitasvir/Dasabuvir and Ribavirin. There are only a few real world reports regarding this therapeutic option in hemodialysis patients.

FIB-4 and APRI scores for predicting severe fibrosis in chronic hepatitis C - a developing country's perspective in DAA era.

INTRODUCTION: Chronic Hepatitis C Virus (HCV) infection leads to progressive fibrosis making fibrosis staging necessary in the evaluation of such patients. Different fibrosis scores are emerging as possible non-invasive alternatives for liver biopsy. The Fibrosis-4 Index (FIB-4) and AST to Platelet Ratio Index (APRI) scores are the most widely used and the most extensively tested. This study aims to determine if it was possible to accurately use these to identify patients that are unlikely to have severe fibrosis. METHODOLOGY: One hundred and forty-two patients with chronic hepatitis C infection who underwent liver biopsy since January 1st 2014 until May 31st 2017 at the Hospital for Infectious and Tropical Diseases in Belgrade were analyzed. The FIB-4 and APRI scores were calculated for each patient and compared to histologically determined fibrosis stage. RESULTS: A comprehensive statistical analysis was conducted in order to compare patients with and without severe fibrosis and to evaluate the accuracy of the fibrosis scores. Patients with non-severe fibrosis were younger, had higher platelet counts and lower transaminase levels. FIB-4 had an AUC of 0.875 and the APRI score had an AUC of 0.861. No patients with severe fibrosis or cirrhosis had a FIB-4 lower than 1.08. FIB-4 was superior to APRI in identifying patients with severe fibrosis in the study cohort. CONCLUSION: FIB-4 was superior to APRI in the recognition of severe fibrosis. FIB-4 may prove very useful in identifying patients without advanced liver disease, especially if other non-invasive methods are inaccessible.

High Frequency of Human Leukocyte Antigen-B*57:01 Allele Carriers among HIV-Infected Patients in Serbia.

Abacavir is an effective antiretroviral drug and one of the most commonly used nucleoside reverse transcriptase inhibitors in Serbia. А percentage of the treated patients experience a potentially life-threatening hypersensitivity reaction, which was shown to be associated with the presence of the class I MHC allele, HLA-B*57:01; hence genotyping for HLA-B*57:01 prior to starting abacavir is nowadays recommended in international HIV treatment guidelines. In Serbia, this testing became available in 2013. This study was designed to estimate the prevalence of the HLA-B*57:01 allele in Serbian HIV-1-infected patients. The presence of the HLA-B*57:01 allele was analyzed in 273 HIV-1-infected patients aged 18 years or more, who were abacavir naïve. Buccal swab samples were obtained from all participants and assayed for the presence of HLA-B*57:01 using a commercially available HLA-B*57:01 real-time PCR kit. The presence of the HLA-B*57:01 allele was found in 22 of 273 tested individuals (8%; 95% CI 5.4-11.9%). This is the first study that estimated the HLA-B*57:01 prevalence among HIV-infected patients in Serbia. The very high prevalence of HLA-B*57:01 found in our study strongly supports HLA-B*57:01 genotyping, which should be implemented prior to the initiation of an abacavir-containing therapy to reduce the risk of potentially life-threatening hypersensitivity reactions.

The increasing prevalence of HIV/Helicobacter pylori co-infection over time, along with the evolution of antiretroviral therapy (ART).

Helicobacter pylori (H. pylori) is one of the most common human bacterial infections with prevalence rates between 10-80% depending upon geographical location, age and socioeconomic status. H. pylori is commonly found in patients complaining of dyspepsia and is a common cause of gastritis. During the course of their infection, people living with HIV (PLHIV) often have a variety of gastrointestinal symptoms including dyspepsia and while previous studies have reported HIV and H. pylori co-infection, there has been little data clarifying the factors influencing this. The aim of this case-control study was to document the prevalence of H. pylori co-infection within the HIV community as well as to describe endoscopic findings, gastritis topography and histology, along with patient demographic characteristics across three different periods of time during which antiretroviral therapy (ART) has evolved, from pre- highly active antiretroviral therapy (HAART) to early and modern HAART eras. These data were compared to well-matched HIV negative controls. Two hundred and twelve PLHIV were compared with 1,617 controls who underwent their first esophagogastroduodenoscopy (EGD) to investigate dyspepsia. The prevalence of H. pylori co-infection among PLHIV was significantly higher in the early (30.2%) and modern HAART period (34.4%) compared with those with coinfection from the pre-HAART period (18.2%). The higher rates seen in patients from the HAART eras were similar to those observed among HIV negative controls (38.5%). This prevalence increase among co-infected patients was in contrast to the fall in prevalence observed among controls, from 60.7% in the early period to 52.9% in the second observed period. The three PLHIV co-infected subgroups differed regarding gastritis topography, morphology and pathology. This study suggests that ART has an important impact on the endoscopic and histological features of gastritis among HIV/H. pylori co-infected individuals, raising the possibility that H. pylori-induced gastritis could be an immune restoration disease.

Intravenous drug use - an independent predictor for HCV genotypes 3 and 4 infection among HIV/HCV co-infected patients.

INTRODUCTION: About one quarter of human immunodeficiency virus (HIV) infected persons in Serbia have also been found to be hepatitis C virus (HCV) co-infected. In the general population, HCV genotype 1 has been shown to be the most prevalent one. Here, we present the first study on the distribution of HCV genotypes among HIV/HCV co-infected patients in Serbia, in relation to epidemiological and clinical features. MATERIAL AND METHODS: The study included HIV/HCV co-infected and a group of HCV mono-infected patients in the period 1998-2012, with collection of epidemiological, clinical, and behavioral data using a standardized questionnaire. The HCV genotyping to the level of pure genotype was performed by reverse hybridization. RESULTS: Intravenous drug use (IDU) was found to be significantly more prevalent among the co-infected patients (p < 0.01). HCV genotype 1 was detected in 87% of patients with mono-infection, compared to 46.3% of patients with co-infection (p < 0.01); genotypes 3 and 4 were significantly more common among co-infected patients (6% and 5%, vs. 27% and 25%, respectively). Multivariate logistic regression confirmed IDU, infection with non-1 HCV genotype and HCV viral load over 5 log to be predictors of HIV co-infection. CONCLUSIONS: The HCV genotypes 3 and 4 were found to be significantly more prevalent among HIV/HCV co-infected patients in Serbia, compared to HCV mono-infected patients, but also more prevalent compared to the European HIV/HCV co-infected cohort. History of IDU represents an independent predictor of HCV genotypes 3 and 4 infection, with important implications for treatment.

Forensic application of phylogenetic analyses - Exploration of suspected HIV-1 transmission case.

Transmission of human immunodeficiency virus (HIV) between individuals may have important legal implications and therefore may come to require forensic investigation based upon phylogenetic analysis. In criminal trials results of phylogenetic analyses have been used as evidence of responsibility for HIV transmission. In Serbia, as in many countries worldwide, exposure and deliberate transmission of HIV are criminalized. We present the results of applying state of the art phylogenetic analyses, based on pol and env genetic sequences, in exploration of suspected HIV transmission among three subjects: a man and two women, with presumed assumption of transmission direction from one woman to a man. Phylogenetic methods included relevant neighbor-joining (NJ), maximum likelihood (ML) and Bayesian methods of phylogenetic trees reconstruction and hypothesis testing, that has been shown to be the most sensitive for the reconstruction of epidemiological links mostly from sexually infected individuals. End-point limiting-dilution PCR (EPLD-PCR) assay, generating the minimum of 10 sequences per genetic region per subject, was performed to assess HIV quasispecies distribution and to explore the direction of HIV transmission between three subjects. Phylogenetic analysis revealed that the viral sequences from the three subjects were more genetically related to each other than to other strains circulating in the same area with the similar epidemiological profile, forming strongly supported transmission chain, which could be in favour of a priori hypothesis of one of the women infecting the man. However, in the EPLD based phylogenetic trees for both pol and env genetic region, viral sequences of one subject (man) were paraphyletic to those of two other subjects (women), implying the direction of transmission opposite to the a priori assumption. The dated tree in our analysis confirmed the clustering pattern of query sequences. Still, in the context of unsampled sequences and inherent limitations of the applied methods, we cannot unambiguously prove that HIV-1 transmission occurred directly between two individuals. Further exploration of the known and suspected transmission cases is needed in order to define methodologies and establish their reliability.

Ten years survey of primary HIV-1 resistance in Serbia: the occurrence of multiclass resistance.

In Serbia, the first cases of HIV infection were reported in 1985, whereas antiretroviral (ARV) therapy has been in use since 1987. With this study we aimed to assess the occurrence and pattern of HIV resistance mutations among newly diagnosed patients in the period 2002-2011. The study prospectively included 181 adult patients. Genotypic HIV-1 drug resistance testing was performed and drug resistance was scored according to the 2009 WHO list for surveillance of drug resistance mutations (SDRMs). A bioinformatic approach was used to estimate the duration of infection by calculating the percentage of ambiguous basecalls per sequence, with a cutoff of 0.47% as the delimiter for recent infection. The overall prevalence of transmitted drug resistance (TDR) found in the study was 8.8% (16/181, 95% CI=5.5-13.8). Thirty-one percent of resistant samples contained multiple SDRMs. In particular, 5/16 patients with resistance carried viral strains with SDRMs to multiple ARV classes, hence one-third of resistant strains were multiclass resistant, including non-B strains. A total of 51.9% of samples (94/181) were classified as recent infection, with a significant increase in the second part of the study period. However, the prevalence of TDR in recent infection was 6.4% (6/94, 95% CI=2.9-13.2), not statistically different from that found in nonrecent infection. We showed a changing pattern of TDR mutations over the study period, with a substantial occurrence of multiclass resistance, across different HIV subtypes. Our results highlight the need for continued surveillance of primary resistance.

Molecular typing of the local HIV-1 epidemic in Serbia.

Worldwide HIV-1 pandemic is becoming increasingly complex, with growing heterogeneity of subtypes and recombinant viruses. Previous studies have documented HIV-1 subtype B as the predominant one in Serbia, with limited presence and genetic diversity of non B subtypes. In recent years, MSM transmission has become the most frequently reported risk for HIV infection among newly diagnosed patients in Serbia, but very little is known of the network structure and dynamics of viral transmission in this and other risk groups. To gain insight about the HIV-1 subtypes distribution pattern as well as characteristics of HIV-1 transmission clusters in Serbia, we analyzed the genetic diversity of the pol gene segment in 221 HIV-1-infected patients sampled during 2002-2011. Subtype B was found to still be the most prevalent one in Serbia, accounting for over 90% of samples, while greater diversity of other subtypes was found than previously reported, including subtypes G, C, A, F, CRF01 and CRF02. In total, 41.3% of analyzed subtype B sequences were found associated in transmission clusters/network, that are highly related with MSM transmission route.

The prognosis of late presenters in the era of highly active antiretroviral therapy in serbia.

To examine the prognosis of patients who present with very advanced HIV-induced immunodeficiency, and their response to highly active antiretroviral therapy (HAART), a series of 101 treatment naïve patients from the Serbian cohort of HIV infected patients, who presented with a CD4 count of