Immunological mechanisms involved in the genesis of the immune response against viral infections take into account the activation of both innate adaptative response. Innate immune defenses trigger a rapid local response, which is often sufficient to control viral infection, and promotes the subsequent activation of specific immune defenses. Natural killer (NK) cells that constitute a subpopulation of lymphocyte-related cells are a key factor of innate immune response and play a role in defense against viral infections by killing infected cells or by producing cytokines and interacting with adaptative immune system's cells. Killer immunoglobulin-like receptors (KIRs) regulate the activation of NK cells through their interaction with human leukocyte antigens (HLA). KIRs and HLA loci are highly polymorphic and certain HLA-KIRs combinations have been found to protect against viral infections. In this study we review how the KIRs/HLA repertoire may influence the course of hepatitis B virus (HBV), hepatitis C virus (HCV), cytomegalovirus (CMV) and Herpes Simplex Virus 1 (HSV-1) infection. Results of our study suggest that a combination of KIRs/HLA gene/alleles is able to predict the outcome of viral infection and allows to plan successful customized therapeutic strategies.

BACKGROUND: In Western Europe, a previously subtype B HIV-1 restricted area, BC recombinants have been rarely reported. OBJECTIVE: To describe an outbreak of HIV-1 BC recombinants in southern Italy. STUDY DESIGN: We analyzed pol (protease/reverse transcriptase) sequences from 135 newly diagnosed HIV-1-infected patients during the years 2009-2011. For phylogenetic relationships, sequences were aligned to the most recent reference data set from the Los Alamos database using BioEdit (version 7.1.3). The resulting alignment was analyzed with the Phylip package (version 3.67) building a neighbor-joining tree based on the Kimura two-parameter substitution model. The reliability of the tree topology was assessed through bootstrapping using 1000 replicates. The recombination pattern was characterized using SimPlot 3.5.1 and SplitsTree 4. RESULTS: At phylogenetic analysis, 22 (16.2%) isolates whose sequences were not unequivocally assigned to a pure subtype or known CRF, formed a distinct monophyletic clade (100% of bootstrap value). For these isolates, the recombination analysis identified a BC mosaic pattern with two breakpoints at positions 2778±5 and 3162±8 (HXB2 numbering) which differed from those of known BC CRFs. All patients from whom these sequences were derived were highly educated youth Italians, 91% males and 82% MSM. Sequences of pol integrase, gp120 and gp41 from these same patients were classified as C subtype. CONCLUSIONS: This outbreak which further reflects the increasing heterogeneity of HIV epidemic in our country is the first report of an Italian outbreak of a BC recombinant, possibly a novel candidate CRF

The aim of the study was to quantify the risk of a drop in CD4 counts below 200 cells/μL after reaching values >350 cells/μL on antiretroviral therapy (ART) (or after starting ART with CD4 count >350 cells/μL) in the absence of virological failure.

In HIV-infected patients a low CD4:CD8 ratio can persist despite CD4 recovery with long-term antiretroviral treatment (ART). As CD4:CD8 inversion is considered a marker of immune-senescence, we aimed to assess if it was associated with the chronic inflammation state in aging patients with HIV. A total of 112 patients with a >15 year history of HIV infection and ART were included, 85 of whom were suppressed. All subjects were tested for interleukin (IL)-6, high-sensitivity (hs)-PCR, and D-dimer levels. Complete clinical, therapeutic, and hematochemical data were retrieved. Coreceptor tropism based on HIV-DNA gp120 genotyping was also available within the past 6 months. A progressive increase in the CD4:CD8 ratio over time was observed without reaching a plateau. Based on the CD4:CD8 ratio at the time of testing, patients were classified into group A (normal ratio ≥0.9) and group B (<0.9). A normal ratio was observed in 37% of patients. Variables associated with an inverted CD4:CD8 ratio were older age, nadir CD4, and detectable HIV viremia. No association between HIV subtype, coreceptor tropism, cytomegalovirus (CMV), hepatitis B virus (HBV), and hepatitis C virus (HCV) coinfections and CD4:CD8 ratio was observed. Group B patients showed a trend for a higher frequency of diabetes and hypertriglyceridemia compared to group A patients, but they did not differ in IL-6, hs-PCR, and D-dimer levels or in frequency of severe non-AIDS-associated events. In conclusion, CD4:CD8 ratio normalization occurs rarely, even after several years of ART. Chronic inflammation in patients aging with HIV does not seem to be directly dependent on the CD4:CD8 ratio. However, the persistent immune dysregulation expressed by a CD4:CD8 inversion might be linked to a higher risk of non-AIDS events, especially metabolic disorders.

Dengue fever (DF), an arbovirosis caused by Dengue viruses (DV, serotypes 1-4), is responsible for an increasing number of travel-related acute febrile illnesses due to population growth, climate changes, spreading by viremic travellers, and improved laboratory diagnosis. The presence of efficient vectors (mosquito Aedes albopictus) has also been described in temperate regions including Italy which is considered the most heavily infected European country. Normally characterized by non-specific signs and symptoms, DF incidence is probably underestimated, especially in non-endemic countries, but the risk of severe forms is substantial. Between August and November 2013, five DF patients (4 males, age 23-38) were observed in the Infectious Disease Clinic (University of Bari, Southern Italy). All had just returned from DF endemic areas (2 French Polynesia, 3 Dominican Republic); 4/5 were hospitalized. Common clinical features included acute febrile syndrome, headache (2 with retro-orbital pain), rash (all patients), two with bleeding manifestations and one with gum bleeding. Laboratory tests demonstrated leukopenia (4 patients), elevated liver enzymes (3 patients), and thrombocytopenia (1 patient). Serum samples for DV antibodies and RNA detection were analyzed by the Regional Arbovirosis Reference Laboratory. Viral RNA was identified in 2/5 patients (DV-4) and seroconversion in the remaining cases. All patients made a complete recovery. Recent literature was reviewed, focusing on epidemiology and vector distribution (especially European and Italian territories), pathogenesis, clinical features, diagnosis, and treatment including vaccine strategies. The occurrence of 5 DF cases during the period of highest vector activity (June-November) in Italy emphasizes the risk of local outbreaks in temperate regions. This paper highlights the importance of clinical alert for dengue also in non-endemic countries.

Although HIV/HCV co-infected individuals were historically considered a "difficult to treat" population in the era of Interferon (IFN)-based anti-HCV treatment, the introduction of direct-acting antivirals, characterized by excellent efficacy and good safety profile, has widely revolutionized the HCV treatment scenario. Recent real life studies reported excellent sustained virological response rates in HIV/HCV co-infected subjects, thus confirming data obtained in randomized clinical trials. However, certain issues have recently emerged in this population. In fact, high rates of acute HCV infection and reinfections were documented in several studies, particularly in HIV-positive men who have sex with men. Moreover, drug-drug interactions with ART or other co-medications may require careful considerations as well as the management of HIV/HCV co-infected subjects with chronic kidney disease and advanced liver disease in the course of a DAA-based treatment. Hence, we aim to review DAA efficacy studies performed in HIV/HCV co-infected patients in both randomized clinical trials and real-world cohorts. In addition, current challenges and future perspectives are discussed in order to optimize management strategies for HIV/HCV co-infected subjects and their access to care in clinical practice.

BACKGROUND: In HIV/HCV co-infected patients, HIV-1 gp120 activates human hepatic stellate cells (HSCs) which play a key role in fibrosis pathogenesis. It is still unclear whether pro-fibrogenic effects are more attributable to X4 or R5 strains in vivo. OBJECTIVE: To assess if HIV-1 X4 or R5 variants are associated with a different progression of fibrosis. STUDY DESIGN: A total of 105 HIV/HCV co-infected patients were submitted to gp120 sequencing on proviral DNA and classified as X4 or R5 based on g2p (20% false positive rate). The fibrosis evolution was retrospectively determined by means of APRI and FIB-4 scores at 3-month intervals from the first anti-HCV-positive test. The association of co-receptor tropism with increased fibrosis scores was evaluated by linear mixed models. RESULTS: X4 variants were found in 41 patients (39%). The median observation period was similar in X4 and R5 patients (17 years). No difference was observed between the two groups of patients, except for nadir CD4 which was lower in X4 compared to R5 (percentage, p=0.005, and absolute number, p=0.005). X4 and R5 patients did not significantly differ for FIB-4 and APRI score over time (p=0.5, and p=0.1, respectively). No association between HCV-RNA levels over time and co-receptor tropism was noted (p=0.9). Conversely, a significant correlation of fibrosis scores with gamma-glutamyl transferase levels, lower current CD4 count, HIV viremia and use of antiretrovirals was observed. CONCLUSIONS: This retrospective analysis of fibrosis evolution did not support the evidence of a differing pro-fibrogenic activity for X4 and R5 HIV-1 variants in HIV/HCV co-infected patients.

BACKGROUND: The continuing migration of individuals from geographic areas with high/medium endemicity has determined the arrival of new chronic hepatitis B virus (HBV) carriers in Italy. The magnitude of this phenomenon and clinical/virological features of HBsAg-positive migrants remain not very well defined. AIMS: To evaluate the proportion of HBsAg-positive immigrants enrolled in this multicenter Società Italiana di Malattie Infettive e Tropicali (SIMIT) cross-sectional study and to compare the characteristics of chronic hepatitis B infection in migrants to those of Italian carriers. METHODS: From February 1 to July 31 2008, anonymous data were obtained from all HBsAg-positive patients aged ≥ 18 years observed at 74 Italian centers of infectious diseases. RESULTS: Of the 3,760 HBsAg-positive subjects enrolled, 932 (24.8 %) were immigrants, with a prevalent distribution in central to northern Italy. The areas of origin were: Far East (37.1 %), Eastern Europe (35.4 %), Sub-Saharan Africa (17.5 %), North Africa (5.5 %), and 4.5 % from various other sites. Compared to Italian carriers, migrants were significantly younger (median age 34 vs. 52 years), predominantly female (57.5 vs. 31 %), and most often at first observation (incident cases 34.2 vs. 13.3 %). HBeAg-positives were more frequent among migrants (27.5 vs. 14 %). Genotype D, found in 87.8 % of Italian carriers, was present in only 40 % of migrants, who were more frequently inactive HBV carriers, with a lower prevalence of chronic hepatitis, cirrhosis, and hepatocellular carcinoma (HCC). Only 27.1 % of migrants received antiviral treatment compared to 50.3 % of Italians. CONCLUSIONS: Twenty-five percent of all HBV carriers examined at Italian centers was composed of immigrants with demographic, serological, and virological characteristics that differed from those of natives and appeared to have an inferior access to treatment.

HIV coreceptor tropism (CTR) testing is a prerequisite for prescribing a coreceptor antagonist. CTR is increasingly deduced by analyzing the V3 loop sequence of gp120. We investigated the impact of mutations outside V3 on CTR as determined by the enhanced-sensitivity Trofile assay (ESTA). Paired ESTA and gp120 sequencing (population sequencing; from codon 32 of the conserved C1 to the variable V5 domains) were obtained from 60 antiretroviral treatment (ART)-naïve patients (15 with AIDS) infected with subtype B HIV-1. For gp120 sequence analysis, nucleotide mixtures were considered when the second highest electropherogram peak was >25%; sequences were translated into all possible permutations and classified as X4, dual/mixed (DM), and R5 based on coincident ESTA results. ESTA identified R5 and DM viruses in 72 and 28% of patients, respectively; no pure X4 was labeled. Forty percent of AIDS patients had R5 strains. Thirty-two positions, mostly outside V3, were significantly (P < 0.05) different between R5 and DM sequences. According to multivariate analysis, amino acid changes at 9 and 7 positions within the C1 to C4 and V1 to V5 regions, respectively, maintained a statistical significance, as did the net charge of V3 and C4. When analyzing only R5 sequences, 6 positions in the variable regions were found which, along with the V4 net charge, were significantly different for sequences from early- and end-stage disease patients. This study identifies specific amino acid changes outside V3 which contribute to CTR. Extending the analysis to include pure X4 and increasing the sample size would be desirable to define gp120 variables/changes which should be included in predictive algorithms.

To compare clinical characteristics and therapeutic management of newly HIV-diagnosed immigrants to natives. Patients with a first HIV diagnosis from 1996 to 2010 were included. Of 716 new diagnoses, 85 (12 %) were immigrants. Migrants were younger, more frequently females and sexually infected, less likely to voluntarily request testing, and less HCV-coinfected. Late presenters (CD4 <350 or AIDS) were 76 % among migrants versus 56 % in natives (p = 0.006) with an increasing trend over time. HAART was initiated in 76.5 % of natives and 72.4 % of immigrants; the number/type of adverse events and treatment discontinuation were similar. Immigrants received more NNRTIs-based regimens. A similar proportion of patients reached virological suppression at month 1-3-6 after HAART initiation, but 43 % of immigrants versus 27 % of natives resulted lost to follow-up (p < 0.001). Diagnosis of HIV was often delayed among migrants, who also presented a higher rate of lost to follow-up.

Objective: To develop sustainable recipes, using local food resources, as a possible solution to manage children malnutrition and nutritional lack in Mozambique, thus preventing infectious diseases. Methods: Our work was based on the Dietary Reference Intake (DRI) reports for children aged 4-8 years old. After having listed more than 60 commonly consumed local foods in Mozambique, we developed some recipes, indicating composition, energy and nutrients values. Information on nutrients concentrations was taken from the National Nutrient Database for Standard References, the Food Composition Tables for Mozambique and the Research Center for Aliments and Nutrition. In the recipes, the traditional way of listing ingredients was reported, which were then turned into international, standardized values. Results: We elaborated some different local food recipes, easy to prepare, at low cost and useful in a systematic approach in order to fight malnutrition in Sofala Province, Mozambique. Each recipe included functions and daily Recommended Dietary Allowance (RDA) of: water, proteins, lipids, carbohydrates, fibers, sodium, potassium, iron, calcium, phosphorus and vitamins. We suggested recipes richer in vitamins and micro/macro nutrients for breakfast, while those providing high caloric intake were more indicated for the main meal. The resulting recipes have been made understandable, for both local and international population, thanks to the coexistence of traditional and international description of ingredients. Conclusion: Local recipes approach is a possible promising tool among the most cost-effective/high impact interventions against child malnutrition and mortality from infectious diseases in Mozambique.

We investigated the association between persistent low-level viraemia, measured as viraemia copy-years (VCY), and all-cause mortality.

Patients co-infected with hepatitis C virus (HCV) and human immunodeficiency virus (HIV) are at high risk of liver disease progression. We report a favorable safety profile and SVR12 rates of 96.7% among HIV/HCV co-infected patients participating in an Italian compassionate-use program of ombitasvir/paritaprevir/ritonavir + dasabuvir (OBV/PTV/r + DSV) ± ribavirin (RBV).

Objective: The DIVA study is aimed at setting up a standardized genotypic tropism-testing on proviral-DNA for the routine clinical diagnostic-laboratory. Methods: Twelve local centres and 5 reference centres (previously cross-validated) were identified. For inter-center validation-procedure, 60 peripheral-blood mononuclear cells (PBMCs) aliquots from 45 HAART-treated patients were randomly chosen for population V3 sequencing on proviral-DNA at local HIV centre and at reference-laboratory. Viral tropism was predicted by Geno2Pheno algorithm (False Positive Rate [FPR] = 20%) as proposed by the European-Guidelines. Quantification of total HIV-1 DNA was based on a method described by Viard (2004). Results: Quantification of HIV-1 DNA was available for 35/45 (77.8%) samples, and gave a median value of 598 (IQR:252- 1,203) copies/10 PBMCs. A total of 56/60 (93.3%) samples were successfully amplified by both the reference and the local virological centers. The overall concordance of tropism prediction between local and reference centers was 54/56 (96.4%). Results of tropism prediction by local centers were: 33/54 (61.1%) R5 and 21/54 (38.9%) X4/DM. Conclusion: There was high concordance in the genotypic tropism prediction based on proviral DNA among different virological centers throughout Italy. Our results are in line with other European studies, and support the use of genotypic tropism testing on proviral DNA in patients with suppressed plasma HIV-1 RNA candidate to CCR5-antagonist treatment.

OBJECTIVE: The goal of the OSCAR programme is to evaluate the performances of genotypic HIV-1 tropism testing in clinical practice using the enhanced sensitivity version of Trofile (ESTA) as reference-assay. METHODS: HIV-1 coreceptor-usage was assessed using plasma samples from 406 HIV-1 infected patients by ESTA and by gp120 V3 population-sequencing followed by Geno2pheno (set at a False Positive Rate [FPR] of 10% and 5%). RESULTS: ESTA was successful in 365 (89.9%) samples indicating R5 in 254 (69.6%), and DM/X4 in 111 (30.4% of samples (104 [28.5%] DM and 7 [1.9%] X4). Genotypic-testing successfully assessed viral tropism for all 406 samples, including the 41 with undetermined result by ESTA. Genotypic-tropism testing at a FPR of 5% and 10% was 81.1% and 78.4% concordant with ESTA, respectively. Despite a sensitivity of 48.7% and 55.9% at a FPR of 5% and 10%, respectively, a high concordance (specificity: 95.3% for FPR of 5% and 88.2% for FPR of 10%) between genotypic-tropism testing and ESTA was reached in the detection of R5-tropic viruses. CONCLUSION: Our results are in line with other European studies, and support the routine use of genotypic tropism testing in clinical-settings for monitoring of HIV-1 infected patients candidate to or failing CCR5-antagonists.

Background: Mozambique presents a very high prevalence of both malaria and HIV infection, but the impact of co-cancel infection on morbidity in this population has been rarely investigated. The aim of this study was to describe the prevalence and clinical characteristics of malaria in hospitalized adult HIV-positive patients, treated and untreated with combination anti-retroviral therapy (ART) and cotrimoxazole (CTX)-based chemoprophylaxis, compared to HIV negatives. Methods: From November to December 2010, all adult patients consecutively admitted to the Department of Internal Medicine of Beira Central Hospital, Sofala Province, Mozambique, were submitted to HIV testing, malaria blood smear (MBS) and, in a subgroup of patients, also to the rapid malaria test (RDT). Socio-demographical and clinical data were collected for all patients. The association of both a positive MBS and/or RDT and diagnosis of clinical malaria with concomitant HIV infection (and use of CTX and/or ART) was assessed statistically. Frequency of symptoms and hematological alterations in HIV patients with clinical malaria compared to HIV negatives was also analysed. Sensitivity and specificity for RDT versus MBS were calculated for both HIV-positive and negative patients. Results: A total of 330 patients with available HIV test and MBS were included in the analysis, 220 of whom (66.7%) were HIV-positive. In 93 patients, malaria infection was documented by MBS and/or RDT. RDT sensitivity and specificity were 94% and 96%, respectively. According to laboratory results, the initial malaria suspicion was discarded in about 10% of cases, with no differences between HIV-positive and negative patients. A lower malaria risk was significantly associated with CTX prophylaxis (p=0.02), but not with ART based on non nucleoside reverse-transcriptase inhibitors (NNRTIs). Overall, severe malaria seemed to be more common in HIV-positive patients (61.7%) compared to HIV-negatives (47.2%), while a significantly lower haemoglobin level was observed in the group of HIV-positive patients (9.9±2.8mg/dl) compared to those HIV-negative (12.1±2.8mg/dl) (p=0.003). Conclusions: Malaria infection was rare in HIV-positive individuals treated with CTX for opportunistic infections, while no independent anti-malarial effect for NNRTIs was noted. When HIV and malaria co-infection occurred, a high risk of complications, particularly anaemia, should be expected.

Country-specific forecasts of the growing non-communicable disease (NCD) burden in ageing HIV-positive patients will be key to guide future HIV policies. We provided the first national forecasts for Italy and the Unites States of America (USA) and quantified direct cost of caring for these increasingly complex patients.

Single nucleotide polymorphisms (SNPs) rs12979860 and rs8099917 near the interleukin 28B gene are predictors of virological response (SVR) to IFN-based therapy for monoinfected chronic hepatitis C patients. We retrospectively evaluated the impact of IL28B SNPs and other factors on SVR in a cohort of 102 HIV-1/HCV-coinfected patients treated with pegylated interferon-? (peg-INF?) and ribavirin. Data on baseline features and virological response at different time-points were collected. Overall, 89/102 patients (87%) were males, 44 (43%) of whom infected with HCV genotype 1; SVR was achieved by 50 patients (49%). A univariate logistic regression analysis demonstrated that rs129679860 SNP genotype CC (p<0.034), rs8099917 SNP genotype TT (p<0.01), HCV genotype 2 or 3 (p<0.0001), low HCV viral load (p<0.028) and RVR (rapid virological response) (p<0.0001) were associated with a higher likelihood of SVR. Multivariate analysis confirmed only RVR and HCV genotype as independent predictors of SVR. In a real life setting, the importance of RVR and IL28B SNPs was confirmed as predictive of SVR to identify patients with a higher likelihood of SVR to Peg-INF?+RBV, and also to designate a deferred therapy for patients with a low likelihood of SVR for whom it is preferable to wait for more successful options.

Dual therapy refers to combinations of two antiretroviral drugs applied in different clinical settings; they are considered and studied due to possibly reduced drug toxicities. In antiretroviral-naive patients, dual combinations have lower virologic efficacy than standard therapy; the sole efficacious regimen is lamivudine plus lopinavir/ritonavir. Due to a higher possibility of virologic failure, these regimens are generally not allowed in this clinical setting. In antiretroviral-experienced patients, dual regimens are examined in studies with a small sample size, centered on clinical practice, and should be ritonavir-boosted protease inhibitor-based. These combinations have a good virological efficacy; combinations with the integrase inhibitor raltegravir have small sample size and demonstrated efficacy only with etravirine. Virological aspects involving dual therapy should always consider genetic barriers, particularly in simplification strategies, and ritonavir-boosted protease inhibitors are mandatory. As far as immunological aspects are concerned, nucleoside reverse transcriptase inhibitor-sparing regimens have some encouraging data, probably due to the bone marrow toxicity of this class. Combinations with maraviroc were effective in reducing inflammation, but data about immunological recovery are conflicting. The choice of regimen should focus on specific class toxicity since dual regimens are studied in particular for improving safety and tolerability. This review will analyze different dual regimens in the clinical setting, with a peculiar focus on ameliorating toxicities and improving quality of life.

OBJECTIVES: We studied survival and associated risk factors in an Italian nationwide cohort of HIV-infected individuals after an AIDS-defining cancer (ADC) or non-AIDS-defining cancer (NADC) diagnosis in the modern cART era. METHODS: Multi-center, retrospective, observational study of HIV patients included in the MASTER Italian Cohort with a cancer diagnosis from January 1998 to September 2012. Malignancies were divided into ADC or NADC on the basis of the Centre for Disease Control-1993 classification. Recurrence of cancer and metastases were excluded. Survivals were estimated according to the Kaplan-Meier method and compared according to the log-rank test. Statistically significant variables at univariate analysis were entered in a multivariate Cox regression model. RESULTS: Eight hundred and sixty-six cancer diagnoses were recorded among 13,388 subjects in the MASTER Database after 1998: 435 (51%) were ADCs and 431 (49%) were NADCs. Survival was more favorable after an ADC diagnosis than a NADC diagnosis (10-year survival: 62.7%±2.9% vs. 46%±4.2%; p = 0.017). Non-Hodgkin lymphoma had lower survival rates than patients with Kaposi sarcoma or cervical cancer (10-year survival: 48.2%±4.3% vs. 72.8%±4.0% vs. 78.5%±9.9%; p<0.001). Regarding NADCs, breast cancer showed better survival (10-year survival: 65.1%±14%) than lung cancer (1-year survival: 28%±8.7%), liver cancer (5-year survival: 31.9%±6.4%) or Hodgkin lymphoma (10-year survival: 24.8%±11.2%). Lower CD4+ count and intravenous drug use were significantly associated with decreased survival after ADCs or NADCs diagnosis. Exposure to cART was found to be associated with prolonged survival only in the case of ADCs. CONCLUSIONS: cART has improved survival in patients with an ADC diagnosis, whereas the prognosis after a diagnosis of NADCs is poor. Low CD4+ counts and intravenous drug use are risk factors for survival following a diagnosis of ADCs and Hodgkin lymphoma in the NADC group

Viral isolation and V3 sequencing were performed for 52 patients with non-subtype B viruses. The HIV-1 isolation rate was 93%, and 98% of isolates were characterized as NSI. V3 sequences corresponding to NSI isolates were compared to non-subtype B sequences with corresponding SI isolates from the Los Alamos database. The two sequence groups significantly differed in number of sequences with 35 amino acids, net charge, Brigg's coefficient, loss of NGS at positions 6-8, and 11/25 genotype (p < 0.0001). Substantial discrepancies in V3 variability were also observed. Basic amino acids at positions 8, 21, 23, and 24 were more frequent in SI sequences as were uncharged amino acids at positions 5, 6, 7, 8, 12, 13, 25, and 34. When characterizing paired viral isolates and V3 sequences from patients with non-subtype B HIV-1, current V3 sequence-based criteria from subtype B appeared to discriminate well between NSI and SI sequences from non-subtype B patients.

Background: Co-receptor tropism (CRT) in patients with a long history of HIV-1 infection and antiretroviral treatment has been rarely investigated to date. The aim of this study was to determine the prevalence of X4 and R5 strains in patients with a >15-year follow-up and to investigate the demographical, viral, immunological, clinical and therapeutic determinants of CRT in this population. The possible influence of CRT on the inflammation state related to chronic HIV infection was also examined. Methods: A total of 118 HIV-1 infected patients with an initial HIV-1-positive test before 1997, and still on follow-up, were enrolled and consecutively submitted to blood sampling. Of these, 111 were on antiretroviral therapy and 89/111 (80.2%) had a plasma viral load (pVL) <25 copies/ml at testing. HIV-1 DNA was extracted and amplified from PBMCs for env gp120 sequencing. CRT was assigned by using geno2pheno and isolates were classified as X4 (FPR ≤20%) or R5 (FPR >20%). Level of serological inflammation biomarkers including IL-6, hsPCR, and D-dimers were measured. Results: An X4 virus was evidenced in HIV-1 proviral DNA of 50 patients (42%) while the remaining 68 patients were classified as R5. The median follow-up was 19 years (range 15–25). No association was observed between CRT and sex, age, nationality, subtype, HIV risk factor, HBV/HCV co-infection, baseline CD4+ cell count and pVL, overall duration of antiretroviral therapy, past exposure to mono-or dual therapies, and duration of NNRTI or PI-based therapy. The presence of an X4 strain was associated with CD4 nadir (p = 0.005), CD4 absolute count over time (p < 0.001), and cumulative positive (copy/years) viremia (p <0.001) during the whole patient history. No differences were found between R5 and X4 patients regarding inflammation marker levels including Il-6, hsPCR and D-dimers. Conclusions: An archived X4 virus was demonstrated in 42% of patients with a >15-year-history of HIV infection. This presence was clearly associated with a greater exposure to positive viremia and a poorer CD4 trend over time compared to R5, independent of type and duration of antiretroviral treatment. CRT does not seem to influence the inflammation rate of patients aging with HIV.