Structural equation modelling of viral tropism reveals its impact on achieving viral suppression within 6 months in treatment-naive HIV-1-infected patients after combination antiretroviral therapy.

OBJECTIVES: To evaluate the role of pre-treatment co-receptor tropism of plasma HIV on the achievement of viral suppression (plasma HIV RNA 1.69 log10 copies/mL) at the sixth month of combination antiretroviral therapy (cART) in a cohort of naive patients using, for the first time in this context, a path analysis (PA) approach. PATIENTS AND METHODS: Adult patients with chronic infection by subtype B HIV-1 were consecutively enrolled from the start of first-line cART (T0). Genotypic analysis of viral tropism was performed on plasma and interpreted using the bioinformatic tool Geno2pheno, with a false positive rate of 10%. A Bayesian network starting from the viro-immunological data at T0 and at the sixth month of treatment (T1) was set up and this model was evaluated using a PA approach. RESULTS: A total of 262 patients (22.1% bearing an X4 virus) were included; 178 subjects (67.9%) achieved viral suppression. A significant positive indirect effect of bearing X4 virus in plasma at T0 on log10 HIV RNA at T1 was detected (P = 0.009), the magnitude of this effect was, however, over 10-fold lower than the direct effect of log10 HIV RNA at T0 on log10 HIV RNA at T1 (P = 0.000). Moreover, a significant positive indirect effect of bearing an X4 virus on log10 HIV RNA at T0 (P = 0.003) was apparent. CONCLUSIONS: PA overcame the limitations implicit in common multiple regression analysis and showed the possible role of pre-treatment viral tropism at the recommended threshold on the outcome of plasma viraemia in naive patients after 6 months of therapy.

Tick-borne encephalitis in north-east Italy: a 14-year retrospective study, January 2000 to December 2013.

Italy is considered at low incidence of tick-borne encephalitis (TBE), and the occurrence of human cases of TBE appears to be geographically restricted to the north east of the country. However, most information to date derives from case series, with no systematic data collection. To estimate incidence rates (IR) and spatial distribution of TBE cases, we conducted a retrospective study in north-eastern Italy. Data were collected through the infectious disease units and public health districts of three regions (Friuli Venezia Giulia, Trentino Alto Adige and Veneto) between 2000 and 2013. Overall, 367 cases were identified (IR: 0.38/100,000). The cases' median age was 56 years and 257 (70%) were male. Central nervous system involvement was reported in 307 cases (84%). Annual fluctuations in case numbers occurred, with peaks in 2006 and in 2013, when 44 and 42 cases were respectively observed. A strong seasonality effect was noted, with the highest number of cases in July. In terms of geographical location, three main endemic foci with high TBE IR (>10/100,000) were identified in three provinces, namely Belluno (Veneto region), Udine (Friuli Venezia Giulia) and Trento (Trentino Alto-Adige). When investigating the whole study area in terms of altitude, the IR between 400 and 600 m was greater (2.41/100,000) than at other altitudes (p<0.01). In conclusion, the incidence of TBE in Italy is relatively low, even considering only the three known affected regions. However, three endemic foci at high risk were identified. In these areas, where the risk of TBEV infection is likely high, more active offer of TBE vaccination could be considered.

A stable CC-chemokine receptor (CCR)-5 tropic virus is correlated with the persistence of HIV RNA at less than 2.5 copies in successfully treated naïve subjects.

BACKGROUND: To determine if tropism for CXCR4 or CCR5 correlates with cellular HIV DNA load, residual viraemia and CD4 count in 219 successfully treated naive subjects with HIV infection enrolled in five infectious diseases units in Northeastern Italy. METHODS: A subset of subjects, achieving plasma HIV RNA level <50 copies/ml after initiation of first-line therapy and maintaining it until follow-up time points, was retrospectively selected from a prospective cohort. Blood samples were collected before the beginning of therapy (T0), at the first follow-up time (T1) and, when available, at a second (T2) follow-up time. RESULTS: HIV DNA, CD4 count and plasma viraemia were available from all 219 patients at T0 and T1, and in 86 subjects at T2, while tropism determinations were available from 109 subjects at T0, 219 at T1, and from 86 subjects at T2. Achieving residual viraemia <2.5 copies/ml at T1 correlated with having the same condition at T2 (p = 0.0007). X4 tropism at T1 was negatively correlated with the possibility of achieving viraemia<2.5 copies/ml at T2 (p = 0.0076). T1-T2 tropism stability was significant (p <0.0001). T0 tropism correlated with T1 and T2 tropism (p < 0.001); therefore the stability of the tropism over the two follow-up periods was significant (p = 0.0003). An effective viremic suppression (viraemia<2.5 copies/ml) correlated with R5 coreceptor affinity (p= 0.047). CONCLUSIONS: The tropism of archived virus was stable during an effective treatment, with 15-18% of subjects switching over time, despite a viraemia<50 copies/ml. R5 tropism and its stability were related to achieving and maintaining viraemia<2.5 copies/ml.

Baseline cellular HIV DNA load predicts HIV DNA decline and residual HIV plasma levels during effective antiretroviral therapy.

Cellular human immunodeficiency virus type 1 (HIV-1) DNA may be considered a marker of disease progression with significant predictive power, but published data on its correlation with plasma HIV RNA levels and CD4 counts in acute and chronic patients are not conclusive. We evaluated a cohort of 180 patients naïve for antiretroviral therapy before the beginning of treatment and after a virological response in order to define the indicators correlated with HIV DNA load decrease until undetectability. The following variables were evaluated as continuous variables: age, CD4 cell count and log(10) HIV DNA level at baseline and follow-up, and baseline log(10) HIV RNA level. Primary HIV infection at the start of therapy, an HIV RNA level at follow-up of <2.5 copies/ml, origin, gender, and transmission risk were evaluated as binary variables. The decline of HIV DNA values during effective therapy was directly related to baseline HIV DNA and HIV RNA values, to an increase in the number of CD4 cells, and to the achievement of an HIV RNA load of <2.5 copies/ml. An undetectable cellular HIV DNA load was achieved by 21.6% of patients at the follow-up time point and correlated significantly with lower baseline cellular HIV DNA values and with being in the primary stage of infection when therapy started. In conclusion, early treatment facilitated the achievement of undetectable levels of plasma viremia and cellular HIV DNA and a better recovery of CD4 lymphocytes. HIV DNA levels before and during highly active antiretroviral therapy may be used as a new tool for monitoring treatment efficacy.

Epidemiology, aetiology and treatment of skin and soft tissue infections: final report of a prospective multicentre national registry.

Skin and soft tissue infections (SSTIs) represent a heterogenous group of pathological conditions involving the skin or the underlying subcutaneous tissues, fascia and muscle, characterised by a considerable variety of clinical presentations, severity and possible aetiological pathogens. Although previous analyses on restricted types of SSTIs and population have already been published, we conducted a large nationwide surveillance program on behalf of the Italian Society of Infectious and Tropical Diseases to assess the clinical and microbiological characteristics of the whole SSTI spectrum, from mild to severe life-threatening infections, in both inpatients and outpatients and their management. Twenty-nine Infectious Diseases (ID) Centres throughout Italy collected prospectively data concerning both the clinical and microbiological diagnosis of patients affected by SSTIs via an electronic case report form. We included in our database all cases managed by ID specialists participating to the study, independently from their severity or the setting of consultation. Here, we integrated previous preliminary results analysing and reporting data referring to a 3-year period (October 2016-October 2019). During this period, the study population included 478 adult patients with diagnosis of SSTI. The type of infection diagnosed, the aetiological agent involved and some notes on antimicrobial susceptibilities were collected and reported herein. We also analysed the most common co-morbidities, the type and duration of therapy executed, before and after ID intervention and the length of stay. The results of our study provide information to better understand the national epidemiologic data and the current clinical management of SSTIs in Italy.

KSHV DNA viremia correlates with low CD4+ cell count in Italian males at the time of diagnosis of HIV infection.

To evaluate the relevance and the virological and immunological markers of Kaposi sarcoma herpesvirus 8 (KSHV) viremia in Italian male patients at the time of diagnosis of infection with HIV-1, 481 men infected with HIV were recruited consecutively. The presence of KSHV DNA was evaluated in peripheral blood mononuclear cells (PBMCs) and in plasma and correlated with demographic and viro-immunological parameters. Seventy-four patients had KSHV DNA detected in PBMCs. By univariate analysis, the presence of KSHV DNA was associated significantly with unprotected homosexual relationships (P=0.003) and it was significantly higher in patients with CD4+ cell <350 (P=0.025). By multivariate analysis, homosexual relationships were associated independently with KSHV DNA in PBMCs (OR: 3.25; 95% CI: 1.1-9.7; P=0.035). Among the 74 patients with KSHV DNA detected in PBMCs, plasma samples from 60 were analyzed and 33 were positive for KSHV DNA. The CD4+ cell counts and percentages were significantly lower in patients with KSHV DNA in both PBMCs and plasma as compared to patients with only KSHV DNA in PBMCs (P=0.006 and P=0.019, respectively). Among the patients with KSHV DNA detected in PBMCs, all 13 patients with CD4+ cells count <200 had detectable levels of KSHV in their plasma. By multivariate analysis adjusted for the epidemiologic and virological parameters, low CD4+ cell count was the only independent variable associated with the presence of KSHV DNA in plasma (OR, 0.001; 95% CI: <0.001-0.001; P=0.03). In HIV-positive antiretroviral therapy-naïve males, KSHV active replication as detected by KSHV DNA in plasma was associated significantly with low CD4+ cell count.

Role of pretreatment variables on plasma HIV RNA value at the sixth month of antiretroviral therapy including all first line drugs in HIV naïve patients: A path analysis approach.

BACKGROUND AND AIMS: We investigated the conditioning roles of viral tropism and other variables on plasma HIV RNA levels after 6 months of combination antiretroviral therapy (cART) in an HIV-infected Italian naïve population using regression tree, random forest regression, and path analysis (PA). Patients in this multicenter observational study were treated with all antiviral drugs that are currently recommended as first-line therapies. METHODS: Adult patients with chronic HIV infection were enrolled at the beginning of first-line cART (T0). The main variables were age, gender, tropism, "lcd4_0" and "lcd4_6" (log10 CD4+counts at T0 and after 6 months of cART, respectively), and "lrna0" (log10 HIV RNA at T0). Regression tree and random forest analyses were applied. The predictive effect on lrna6 (log10-transformed plasma HIV RNA after 6 months of cART) was also investigated via PA (x4->lcd4_0->lrna0->lrna6) with a treatment selection step included as a dependent (mediator) variable for each third drug and, as predictive covariates, age, female, x4_10, x4_5, lcd4_0, and lrna0. Tropism was assessed in plasma using the Geno2pheno algorithm with 2 false positive rate (FPR) cut-offs: 5% (x4_5) and 10% (x4_10). RESULTS: The study included 571 subjects (21% x4_10 and 10.7% x4_5). The only important predictor of lrna6 was lrna0, and a positive indirect effect of bearing X4 virus in plasma was suggested. A significant direct positive effect of protease inhibitors on lrna6 was found (p = 0.022), and a significant negative effect of integrase strand transfer inhibitor (INSTI) was also detected (p = 0.003 for FPR ≤ 5% and p = 0.01 for FPR < 10%). PA predicted mean residual viremias of 40 copies/mL without INSTI and 3 copies/mL with INSTI. CONCLUSIONS: PA indicated a possible indirect role of HIV tropism on lrna6 with both FPR < 10% and ≤ 5%. Patients treated with INSTI had a predicted residual viremia of 3 copies/mL.

Epidemiology and Microbiology of Skin and Soft Tissue Infections: Preliminary Results of a National Registry.

Skin and soft tissue infections (SSTIs) represent a wide range of clinical conditions characterized by a considerable variety of clinical presentations and severity. Their aetiology can also vary, with numerous possible causative pathogens. While other authors previously published analyses on several types of SSTI and on restricted types of patients, we conducted a large nationwide surveillance programme on behalf of the Italian Society of Infectious and Tropical Diseases to assess the clinical and microbiological characteristics of the whole SSTI spectrum, from mild to severe life-threatening infections, in both inpatients and outpatients. Twenty-five Infectious Diseases (ID) Centres throughout Italy collected prospectively data concerning both the clinical and microbiological diagnosis of patients affected by SSTIs via an electronic case report form. All the cases included in our database, independently from their severity, have been managed by ID specialists joining the study while SSTIs from other wards/clinics have been excluded from this analysis. Here, we report the preliminary results of our study, referring to a 12-month period (October 2016-September 2017). During this period, the study population included 254 adult patients and a total of 291 SSTI diagnoses were posed, with 36 patients presenting more than one SSTIs. The type of infection diagnosed, the aetiological micro-organisms involved and some notes on their antimicrobial susceptibilities were collected and are reported herein. The enrichment of our registry is ongoing, but these preliminary results suggest that further analysis could soon provide useful information to better understand the national epidemiologic data and the current clinical management of SSTIs in Italy.

Drug resistance in B and non-B subtypes amongst subjects recently diagnosed as primary/recent or chronic HIV-infected over the period 2013-2016: Impact on susceptibility to first-line strategies including integrase strand-transfer inhibitors.

OBJECTIVES: To characterize the prevalence of transmitted drug resistance mutations (TDRMs) by plasma analysis of 750 patients at the time of HIV diagnosis from January 1, 2013 to November 16, 2016 in the Veneto region (Italy), where all drugs included in the recommended first line therapies were prescribed, included integrase strand transfer inhibitors (InNSTI). METHODS: TDRMs were defined according to the Stanford HIV database algorithm. RESULTS: Subtype B was the most prevalent HIV clade (67.3%). A total of 92 patients (12.3%) were expected to be resistant to one drug at least, most with a single class mutation (60/68-88.2% in subtype B infected subjectsand 23/24-95.8% in non-B subjects) and affecting mainly NNRTIs. No significant differences were observed between the prevalence rates of TDRMs involving one or more drugs, except for the presence of E138A quite only in patients with B subtype and other NNRTI in subjects with non-B infection. The diagnosis of primary/recent infection was made in 73 patients (9.7%): they had almost only TDRMs involving a single class. Resistance to InSTI was studied in 484 subjects (53 with primary-recent infection), one patient had 143C in 2016, a total of thirteen 157Q mutations were detected (only one in primary/recent infection). CONCLUSIONS: Only one major InSTI-TDRM was identified but monitoring of TDRMs should continue in the light of continuing presence of NNRTI-related mutation amongst newly diagnosed subjects, sometime impacting also to modern NNRTI drugs recommended in first-line therapy.

Structural-equation-modelling of the tropism impact on achieving viral suppression within six months in naïve HIV patients.

INTRODUCTION: Aim of the study was to evaluate the relevance of baseline (BL) plasma tropism of HIV on the achievement of a viral suppression within six months of antiviral therapy (ARV) in naïve patients by a structural-equation-modelling. MATERIALS AND METHODS: Two-hundred and twenty-seven patients were enrolled; viral tropism on plasma was determined at baseline (BL) by sequencing and interpretation by genotopheno algorithm. Booster atazanavir or lopinavir , or efavirenz or nevirapine were used, in combination with either abacavir/lamivudine or tenofovir-emtricitabine. RESULTS: X4-tropism correlate negatively with CD4 cell count at BL and follow-up (FU), and CD4 correlate negatively with BL-plasma viremia (PLV). BL-PLV correlate positively with FU-PLV. We have developed the hypothesis that the variables BL-CD4 and BL-PLV represent a mediators chain among X4-tropism and outcome of plasma viraemia at six months. This model, after structural-equation-modelling (SEM, Stata13), is shown in Figure 1. The indirect effect of X4-tropism on Fup-PLV is significant (p<0.01) but about 10 fold lower than the direct effect by BL-PLV. X4-tropism also has a direct negative effect on BL-CD4 (p<0.001) and an indirect positive effect on BL-PLV (p<0.001), irrespective of the drug regimen. Path model explaining direct and mediated effects of "tro (tropism)," "gender," "age," "cd0 (BL-CD4)" and "lrna0 (BL-PLV)" on the final outcome ("lrna1-Fup-PLV)," where "tro," "gender," and "age" are exogenous, cd0 and lrna0 are endogenous (mediators). Numbers on the arrows indicate direct effects. Circles indicate residuals related to endogenous/dependent variables; numbers near to circles are the corresponding variances. CONCLUSIONS: This model shows the relevance of BL-tropism on the outcome of plasma viraemia in naïve patients after six months of therapy, irrespective of drug regimen used.

Decreasing trends of drug resistance and increase of non-B subtypes amongst subjects recently diagnosed as HIV-infected over the period 2004-2012 in the Veneto Region, Italy.

The present study was designed to prospectively monitor transmitted drug resistance mutations (TDRMs) in the Veneto Region, Italy. Genotypic resistance testing was conducted on the plasma of 1882 patients consecutively enrolled at the time of diagnosis of human immunodeficiency virus (HIV) infection from 2004 to 2012. TDRMs were defined according to the Stanford HIV database algorithm. In total, 214 (16.1%) B subtype-infected and 58 (10.5%) non-B subtype-infected individuals were identified as having a primary or recent HIV-1 infection. In subtype B-infected subjects in 2004-2006, the prevalence of TDRMs was 20.0% in chronic infections and 25.5% in recent infections; in 2007-2009 the rates were 11.5% and 5.3%, respectively; and in 2010-2012 they were 11.3% and 15.2%, respectively. In non-B subtype-infected subjects in 2004-2006, the prevalence of TDRMs was 18.0% in chronic infections and 16.5% in recent infections; in 2007-2009 the rates were 5.7% and 0%, respectively; and in 2010-2012 they were 6.2% and 8.7%, respectively. Protease inhibitor resistance and combined resistance to two or three classes of drugs declined during the three study periods. The observed decrease in TDRMs and a simplification of the resistance patterns may reflect a change over time in the characteristics of the infecting subjects who are often unaware of their infection and transmit a wild-type strain.