Intact provirus and integration sites analysis in acute HIV-1 infection and changes after one year of early antiviral therapy.

Background and objectives: HIV-1 provirus integration in host genomes provides a lifelong reservoir of virally infected cells. Although not able to generate viral progeny, the expression of defective proviruses has been associated with activation. Provirus integration may influence host gene transcription and shifts may occur during disease progression or antiretroviral therapy (ART). The study aimed to analyze intact/defective provirus and sites of provirus integration in acute infections: changes after 48 weeks of early therapy were also evaluated. Methods: DNA from peripheral blood lymphomonocytes of 8 acute HIV-1 infections at serodiagnosis (T0) and after 48 weeks of therapy (T1) was used to quantify intact and defective provirus by digital-droplet PCR and to analyze provirus integration sites, by next-generation sequencing of libraries derived from ligation-mediated PCR. Results: A high variability in the amount of intact proviral DNA was observed at both T0 and T1, in the different subjects. Although the ratio of intact/total proviral HIV-1 DNA did not dramatically change between T0 (8.05%) and T1 (9.34%), after early therapy both intact and total HIV-1 DNA declined significantly, p = 0.047 and p = 0.008, respectively. The median number of different (IQR) integration sites in human chromosomes/subject was 5 (2.25-13.00) at T0 and 4 (3.00-6.75) at T1. Of all the integration sites observed at T1, 64% were already present at T0. Provirus integration was observed in introns of transcriptionally active genes. Some sites of integration, among which the most represented was in the neuregulin 2 gene, were shared by different patients, together with the orientation of the insertion. Provirus integration was also observed in intergenic regions, with median (IQR) % of 15.13 (6.81-21.40) at T0 and 18.46 (8.98-22.18) at T1 of all read matches. Conclusions: In acute HIV-1 infection, the amount of intact proviral DNA in peripheral lymphomonocytes did not exceed 10% of total HIV-1 DNA, a percentage that was not substantially changed by early administrated ART. Provirus displayed a relatively small number of recurrent integration sites in introns of transcriptionally active genes, mainly related to cell-cycle control. Consideration should be given to therapeutic strategies able to target the cells harboring defective proviruses, that are not reached by conventional antiviral drugs, these potentially also impacting on replicative competent integrated provirus.

Virological and Immunological Outcomes of an Intensified Four-Drug versus a Standard Three-Drug Antiretroviral Regimen, Both Integrase Strand Transfer Inhibitor-Based, in Primary HIV Infection.

The optimal therapeutic approach for primary HIV infection (PHI) is still debated. We aimed to compare the viroimmunological response to a four- versus a three-drug regimen, both INSTI-based, in patients with PHI. This was a monocentric, prospective, observational study including all patients diagnosed with PHI from December 2014 to April 2018. Antiretroviral therapy (ART) was started, before genotype resistance test results, with tenofovir/emtricitabine and either raltegravir plus boosted darunavir or dolutegravir. Cumulative probability of virological suppression [VS] (HIV-1 RNA< 40 cp/mL), low-level HIV-1 DNA [LL-HIVDNA] (HIV-1 DNA < 200 copies/106PBMC), and CD4/CD8 ratio ≥1 were estimated using Kaplan−Meier curves. Factors associated with the achievement of VS, LL-HIVDNA, and CD4/CD8 ≥ 1 were assessed by a Cox regression model. We enrolled 144 patients (95.8% male, median age 34 years): 110 (76%) started a four-drug-based therapy, and 34 (24%) a three-drug regimen. Both treatment groups showed a comparable high probability of achieving VS and a similar probability of reaching LL-HIVDNA and a CD4/CD8 ratio ≥1 after 48 weeks from ART initiation. Higher baseline HIV-1 RNA and HIV-1 DNA levels lowered the chance of VS, whereas a better preserved immunocompetence increased that chance. Not statistically significant factors associated with LL-HIVDNA achievement were found, whereas a higher baseline CD4/CD8 ratio predicted the achievement of immune recovery. In PHI patients, the rapid initiation of either an intensified four-drug or a standard three-drug INSTI-based regimen showed comparable responses in terms of VS, viral reservoir size, and immunological recovery.

Results of an interventional HIV testing programme in the context of a mpox (formerly monkeypox) vaccination campaign in Latium Region, Italy, August to October 2022.

HIV testing was offered to 2,185 people receiving mpox (formerly monkeypox) vaccination, who reported not being HIV positive. Among them 390 were current PrEP users, and 131 had taken PrEP in the past. Of 958 individuals consenting testing, six were newly diagnosed with HIV. Two patients had symptomatic primary HIV infection. None of the six patients had ever taken PrEP. Mpox vaccination represents an important opportunity for HIV testing and counselling about risk reduction and PrEP.

Molecular Transmission Dynamics of Primary HIV Infections in Lazio Region, Years 2013-2020.

Molecular investigation of primary HIV infections (PHI) is crucial to describe current dynamics of HIV transmission. Aim of the study was to investigate HIV transmission clusters (TC) in PHI referred during the years 2013-2020 to the National Institute for Infectious Diseases in Rome (INMI), that is the Lazio regional AIDS reference centre, and factors possibly associated with inclusion in TC. These were identified by phylogenetic analysis, based on population sequencing of pol; a more in depth analysis was performed on TC of B subtype, using ultra-deep sequencing (UDS) of env. Of 270 patients diagnosed with PHI during the study period, 229 were enrolled (median follow-up 168 (IQR 96-232) weeks). Median age: 39 (IQR 32-48) years; 94.8% males, 86.5% Italians, 83.4% MSM, 56.8% carrying HIV-1 subtype B. Of them, 92.6% started early treatment within a median of 4 (IQR 2-7) days after diagnosis; median time to sustained suppression was 20 (IQR 8-32) weeks. Twenty TC (median size 3, range 2-9 individuals), including 68 patients, were identified. A diagnosis prior to 2015 was the unique factor associated with inclusion in a TC. Added value of UDS was the identification of shared quasispecies components in transmission pairs within TC.

Latent tuberculosis infection screening in persons newly-diagnosed with HIV infection in Italy: A multicentre study promoted by the Italian Society of Infectious and Tropical Diseases.

BACKGROUND: The Italian Society of Infectious and Tropical Diseases performed a survey on the application of guidelines for the management of persons living with HIV (PLWH), to evaluate current practice and the yield of screening for latent tuberculosis infection (LTBI) in newly-diagnosed PLWH; in addition, the offer of preventive therapy to LTBI individuals and the completion rate were analysed. MATERIALS AND METHODS: Newly-diagnosed PLWH in nine centres were evaluated retrospectively (2016/2017) using binary and multinomial logistic regression to identify factors associated with LTBI diagnostic screening and QuantiFERON (QFT) results. RESULTS: Of 801 patients evaluated, 774 were studied after excluding active TB. LTBI tests were performed in 65.5%. Prescription of an LTBI test was associated with being foreign-born (odds ratio (OR) 3.19, p < 0.001), older (for 10-year increments, OR 1.22, p = 0.034), and having a CD4 count <100 cells/mm3 vs ≥500 cells/mm3 (OR 2.30, p = 0.044). LTBI was diagnosed in 6.5% of 495 patients evaluated by QFT. Positive results were associated with being foreign-born (relative risk ratio (RRR) 30.82, p < 0.001), older (for 10-year increments, RRR 1.78, p = 0.003), and having a high CD4 count (for 100 cells/mm3 increments, RRR 1.26, p < 0.003). Sixteen LTBI individuals started TB preventive therapy and eight completed it. CONCLUSIONS: LTBI screening is inconsistently performed in newly-diagnosed PLWH. Furthermore, TB preventive therapy is not offered to all LTBI individuals and compliance is poor.

Naïve/Effector CD4 T cell ratio as a useful predictive marker of immune reconstitution in late presenter HIV patients: A multicenter study.

A significant proportion of HIV-infected patients experiencing a late diagnosis highlights the need to define immunological protocols able to help the clinicians in identifying patients at higher risk for immunological failure. The aim of the study was to evaluate the feasibility of easy cytometric tests in defining the effect of antiretroviral treatment (cART) on immunological homeostasis and in identifying predictive markers of early immune recovery. Chronic HIV infected patients (n = 202) were enrolled in a prospective multicentric study, and their immunological profile was studied before (w0) and after 24 weeks (w24) of antiretroviral treatment (cART) using a standardized flow cytometric panel. Based on CD4 T cell count before treatment, patients were divided in late (LP: CD4 <350/mmc), intermediate (IP: 350/mmc500/mmc) presenters. In all groups, cART introduction increased CD4 and CD4/CD8 T cell ratio, naïve T cell (CD4 and CD8) and CD127-expressing CD4 T cells. In parallel, cART significantly reduced effector memory T cells (CD4 and CD8) and T cell activation (CD38+CD8 and CD95+CD4 T cells). Moreover, the frequency of Naïve and Effector CD4 T cells before treatment correlated with several immune parameters key associated with the pathogenesis of HIV, thus mirroring the health of immune system. Interestingly, we identified the Naïve/Effector CD4 T cell ratio (N/EM) at w0 as a marker able to predict early immune recovery. Specifically, in LP, N/EM ratio was significantly higher in immunological responder patients (CD4>500/mmc at w24) when compared to immunological non responder (CD4 T cells <500/mmc at w24). Finally, a multivariate analysis indicates that after 24w patients with N/EM ratio higher than 1.86 at w0 recovered 96 CD4 T cells more than those with N/EM ratio lower than 0.46. Altogether, our data define an easy protocol able to define reliable immunological markers useful for the characterization of immune profile in viremic HIV patients and identify the naïve/effector CD4 T cell ratio as a new tool able to predict an early immune reconstitution potential.

Characterisation of HIV-1 molecular transmission clusters among newly diagnosed individuals infected with non-B subtypes in Italy.

OBJECTIVE: We evaluated the characteristics of HIV-1 molecular transmission clusters (MTCs) in 1890 newly diagnosed individuals infected with non-B subtypes between 2005 and 2017 in Italy. METHODS: Phylogenetic analyses were performed on pol sequences to characterise subtypes/circulating recombinant forms and identify MTCs. MTCs were divided into small (SMTCs, 2-3 sequences), medium (MMTCs, 4-9 sequences) and large (LMTCs, ≥10 sequences). Factors associated with MTCs were evaluated using logistic regression analysis. RESULTS: 145 MTCs were identified and involved 666 individuals (35.2%); 319 of them (16.9%) were included in 13 LMTCs, 111 (5.9%) in 20 MMTCs and 236 (12.5%) in 112 SMTCs. Compared with individuals out of MTCs, individuals involved in MTCs were prevalently Italian (72.7% vs 30.9%, p<0.001), male (82.9% vs 62.3%, p<0.001) and men who have sex with men (MSM) (43.5% vs 14.5%, p<0.001). Individuals in MTCs were also younger (median (IQR) years: 41 (35-49) vs 43 (36-51), p<0.001) and had higher CD4 cell count in comparison with individuals out of MTCs (median (IQR): 109/L: 0.4 (0.265-0.587) vs 0.246 (0.082-0.417), p<0.001). The viral load remained stable between the two groups (median (IQR) log10 copies/mL: 4.8 (4.2-5.5) vs 5.0 (4.3-5.5), p=0.87). Logistic regression confirmed that certain factors such as being MSM, of Italian origin, younger age and higher CD4 cell count were significantly associated with MTCs. CONCLUSIONS: Our findings show that HIV-1 newly diagnosed individuals infected with non-B subtypes are involved in several MTCs in Italy. These MTCs include mainly Italians and MSM and highlight the complex phenomenon characterising the HIV-1 spread. This is important especially in view of monitoring the HIV epidemic and guiding the public health response.

Unawareness of HCV serostatus among persons newly diagnosed with HIV.

Treatment of chronic HCV infection with direct acting antivirals can achieve high rates of sustained viral response in persons with HIV. In the perspective of HCV elimination in this population, high rates of HCV detection will be needed. We evaluated the unawareness of HCV infection in 2927 persons newly diagnosed with HIV during 2004-2015 in Rome, Italy. Two-hundred-fifty persons (8.5%) were anti-HCV positive. The proportion of HCV-unaware individuals at the time of HIV diagnosis was 58.0% (145/250), without significant variations over time, 17.2% showed an advanced fibrosis stage. The absence of previous HIV testing was significantly associated with HCV unawareness.

The HIV-1 reverse transcriptase polymorphism A98S improves the response to tenofovir disoproxil fumarate+emtricitabine-containing HAART both in vivo and in vitro.

The impact of baseline HIV-1 reverse transcriptase (RT) polymorphisms on response to first-line modern HAART containing tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) was evaluated. The impact of each RT polymorphism on virological success (VS) was evaluated in 604 HIV-1 subtype B-infected patients starting TDF+FTC-containing HAART. TDF and FTC antiviral activity was also tested in PBMCs infected by mutagenised HIV. Structural analysis based on docking simulations was performed. A98S was the only mutation significantly correlated with an increased proportion of patients achieving VS at 24 weeks (94.0% vs. 84.3%; P=0.03). Multivariate regression and Cox model analyses confirmed this result. At concentrations close to the minimal concentration achieved in patient plasma, TDF and FTC exhibited higher potency in the presence of A98S-mutated virus compared with wild-type (IC90,TDF, 8.6±1.1 vs. 19.3±3.5nM; and IC90,FTC, 12.4±7.7 vs. 16.8±9.8nM, respectively). The efficacy of FTC, abrogated by M184V, was partially restored by A98S (IC90,FTC, 5169±5931nM for A98S+M184V vs. 18477±12478nM for M184V alone). Docking analysis showed the higher potency of TDF and FTC in the presence of A98S-mutated virus was mainly due to higher binding affinity between drugs and mutated RT compared with wild-type. In the presence of FTC, A98S also partially restored the RT binding affinity impaired by M184V alone. A98S polymorphism improves virological response to TDF+FTC-containing HAART. This may help clinicians in the choice of the optimal NRTI backbone aimed at achieving maximal virological inhibition.

Recent Transmission Clustering of HIV-1 C and CRF17_BF Strains Characterized by NNRTI-Related Mutations among Newly Diagnosed Men in Central Italy.

BACKGROUND: Increased evidence of relevant HIV-1 epidemic transmission in European countries is being reported, with an increased circulation of non-B-subtypes. Here, we present two recent HIV-1 non-B transmission clusters characterized by NNRTI-related amino-acidic mutations among newly diagnosed HIV-1 infected men, living in Rome (Central-Italy). METHODS: Pol and V3 sequences were available at the time of diagnosis for all individuals. Maximum-Likelihood and Bayesian phylogenetic-trees with bootstrap and Bayesian-probability supports defined transmission-clusters. HIV-1 drug-resistance and V3-tropism were also evaluated. RESULTS: Among 534 new HIV-1 non-B cases, diagnosed from 2011 to 2014, in Central-Italy, 35 carried virus gathering in two distinct clusters, including 27 HIV-1 C and 8 CRF17_BF subtypes, respectively. Both clusters were centralized in Rome, and their origin was estimated to have been after 2007. All individuals within both clusters were males and 37.1% of them had been recently-infected. While C-cluster was entirely composed by Italian men-who-have-sex-with-men, with a median-age of 34 years (IQR:30-39), individuals in CRF17_BF-cluster were older, with a median-age of 51 years (IQR:48-59) and almost all reported sexual-contacts with men and women. All carried R5-tropic viruses, with evidence of atypical or resistance amino-acidic mutations related to NNRTI-drugs (K103Q in C-cluster, and K101E+E138K in CRF17_BF-cluster). CONCLUSIONS: These two epidemiological clusters provided evidence of a strong and recent circulation of C and CRF17_BF strains in central Italy, characterized by NNRTI-related mutations among men engaging in high-risk behaviours. These findings underline the role of molecular epidemiology in identifying groups at increased risk of HIV-1 transmission, and in enhancing additional prevention efforts.

Acute HIV infection (AHI) in a specialized clinical setting: case-finding, description of virological, epidemiological and clinical characteristics.

INTRODUCTION: Diagnosis of HIV infection during early stages is mandatory to catch up with the challenge of limiting HIV viral replication and reservoirs formation, as well as decreasing HIV transmissions by immediate cART initiation. OBJECTIVES: Aims were to describe (a) virological characteristics of AHI identified, (b) epidemiological and clinical factors associated with being diagnosed with AHI. METHODS: Cross-sectional, retrospective study. All individuals diagnosed with AHI according to Fiebig's staging between Jan 2013 and Mar 2014 at the INMI "L. Spallanzani" were included. Serum samples reactive to a fourth generation HIV-1/2 assay (Architect HIV Ag/Ab Combo, Abbott) were retested with another fourth generation assay (VIDAS DUO HIV Ultra, Biomérieux) and underwent confirmation with HIV-1 WB (New Lav I Bio-Rad) and/or with Geenius confirmatory assay (Bio-Rad). WHO criteria (two env products reactivity) were used to establish positivity of confirmatory assays. In case of clinically suspected AHI, HIV-1 RNA (Real time, Abbott) and p24 assay (VIDAS HIV P24 Bio-Rad) were also performed. Avidity test was carried out, on confirmed positive samples lacking p31 reactivity, to discriminate between recent (true Fiebig V phase) and late infections; to avoid possible misclassifications, clinical data were also used. Demographic, epidemiological, clinical and laboratory data are routinely, and anonymously recorded in the SENDIH and SIREA studies. RESULTS: During the study period, we observed 483 newly HIV diagnosed individuals, of whom 40 were identified as AHI (8.3%). Fiebig classification showed: 7 stage II/III, 13 stage IV, 20 stage V. Demographic, epidemiological, and clinical characteristics of patients are shown in the Table. Overall, the study population had a median S/Co ratio at fourth generation EIA (Architect) of 49.50 (IQR, 23.54-98.05): values were significantly lower in Fiebig II-IV than in Fiebig V (38.68 [IQR, 20.08-54.84] vs 75.72 [IQR, 42.66-249.80], p=0.01). Overall, median HIV-1 RNA was 5.44 log copies/mL (IQR, 4.29-6.18) and the value observed in Fiebig phase II-IV was higher than that found in Fiebig stage V (6.10 [IQR, 5.49-7.00] vs 4.69 [3.71-5.44], p<0.001). Median CD4+ cell count was 596/mmc (IQR, 410-737). cART was started in 26 patients: TDF/FTC/DRV/r/RAL=18; TDF/FTC/DRV/r=2; TDF/FTC/ATV/r=2; TDF+FTC+EFV=2; TDF/FTC/RAL=1; DRV/r+RAL=1. CONCLUSIONS: Integration of careful epidemiological investigation, partner notification, and technical advances in virological testing are key elements in AHI case-finding. Significant differences were found between Fiebig stages II-IV and Fiebig V with regard to virological exams.

Early discharge of infectious disease patients: an opportunity or extra cost for the Italian Healthcare System?

In order to assess the economic benefits of an early discharge (ED) programme for patients with complicated skin and soft tissue infections (cSSTIs) in terms of hospital and regional authority costs, an economic analysis was conducted comparing two possible alternatives: standard hospital management vs. an ED strategy followed by a period of outpatient management. Utilization of resources and costs were derived from the literature and expert panel evaluation. Patients were classified into four groups: low-intensity non-walking (LINW), low-intensity walking (LIW), high-intensity non-walking (HINW) and high-intensity walking (HIW). The overall costs (inpatient/outpatient) of hospitalization with ED for cSSTIs range from Euros 2,079 for LIW to Euros 2,193 for HINW, with the most expensive regimen (HINW) being 50% lower than the costs for 12.6 days of hospitalization alone (Euros 4,619). The weighted average Diagnosis Related Group (DRG) reimbursement for cSSTIs (Euros 2,042) does not cover the costs of such hospitalization. In conclusion, when a patient's conditions allow for early discharge there is an economic advantage for the hospital with an outpatient management plan, especially for patients requiring low-intensity care. However, this could be disadvantageous in terms of regional costs if outpatient management has to be paid in addition to payment by the DRG.

Temporal trend and characteristics of recent HIV-1 infections: application of an algorithm for the identification of recently acquired HIV-1 infections among newly diagnosed individuals over a 10-year period.

Identification of recent infections (RI) may contribute to improve the quality of human immunodeficiency virus (HIV) surveillance, monitoring ongoing transmission and planning and evaluating prevention programs. Our study applied an algorithm combining clinical and serological information to identify RI in individuals newly diagnosed with HIV in Rome, during the years 1999-2008, in order to describe the trend and characteristics of recently infected individuals. RI were documented seroconverters, or people with an HIV avidity index (AI)<0.80. Individuals with advanced infection (CD4 count <200 cells/?L or AIDS-defining illness) or with AI ?0.80 were considered long-standing infections. Overall, we observed 2,563 new HIV diagnoses. The algorithm was applied in 2124/2563 (82.9%). Of these, 355 were RI (16.7%). RI was found independently associated with calendar year (adjusted odds ratio [aOR]= 1.06, 95% confidence intervals [CI]=[CI 1.02-1.11], for every year of increase), HIV-risk category (men having sex with men: aOR=1.44, [CI 1.04-1.98]; injecting drug users: aOR=1.58, [CI 1.03-2.42] vs. heterosexuals), country of origin (foreign-born: vs Italians: aOR=0.46, [CI 0.33-0.62]), and recruitment site (inpatient vs outpatient clinic: aOR=0.49, [CI 0.37-0.66]). By the application of our algorithm we could characterize the pattern of ongoing HIV transmission, identifying groups needing more urgent prevention programs.

The potential impact of routine testing of individuals with HIV indicator diseases in order to prevent late HIV diagnosis.

BACKGROUND: The aim of our work was to evaluate the potential impact of the European policy of testing for HIV all individuals presenting with an indicator disease, to prevent late diagnosis of HIV. We report on a retrospective analysis among individuals diagnosed with HIV to assess whether a history of certain diseases prior to HIV diagnosis was associated with the chance of presenting late for care, and to estimate the proportion of individuals presenting late who could have been diagnosed earlier if tested when the indicator disease was diagnosed. METHODS: We studied a large cohort of individuals newly diagnosed with HIV infection in 13 counselling and testing sites in the Lazio Region, Italy (01/01/2004-30/04/2009). Considered indicator diseases were: viral hepatitis infection (HBV/HCV), sexually transmitted infections, seborrhoeic dermatitis and tuberculosis. Logistic regression analysis was performed to estimate association of occurrence of at least one indicator disease with late HIV diagnosis. RESULTS: In our analysis, the prevalence of late HIV diagnosis was 51.3% (890/1735). Individuals reporting at least one indicator disease before HIV diagnosis (29% of the study population) had a lower risk of late diagnosis (OR = 0.7; 95%CI: 0.5-0.8) compared to those who did not report a previous indicator disease. 52/890 (5.8%) late presenters were probably already infected at the time the indicator disease was diagnosed, a median of 22.6 months before HIV diagnosis. CONCLUSIONS: Our data suggest that testing for HIV following diagnosis of an indicator disease significantly decreases the probability of late HIV diagnosis. Moreover, for 5.5% of late HIV presenters, diagnosis could have been anticipated if they had been tested when an HIV indicator disease was diagnosed.However, this strategy for enhancing early HIV diagnosis needs to be complemented by client-centred interventions that aim to increase awareness in people who do not perceive themselves as being at risk for HIV.

Structural modifications induced by specific HIV-1 protease-compensatory mutations have an impact on the virological response to a first-line lopinavir/ritonavir-containing regimen.

OBJECTIVES: This study evaluates the impact of specific HIV-1 protease-compensatory mutations (wild-type amino acids in non-B subtypes) on virological response to a first-line lopinavir/ritonavir-containing regimen in an HIV-1 subtype B-infected population. PATIENTS AND METHODS: The prevalence of protease-compensatory mutations from 1997 to 2011 was calculated in 3063 drug-naive HIV-1 B-infected patients. The role of these mutations on virological outcome is estimated in a subgroup of 201 patients starting their first lopinavir/ritonavir-containing regimen by covariation and docking analyses. RESULTS: The number of HIV-1 B-infected patients with at least one protease-compensatory mutation increased over time (from 86.4% prior to 2001 to 92.6% after 2009, P = 0.02). Analysing 201 patients starting first-line lopinavir/ritonavir, the median time to virological failure was shorter in patients with at least one protease-compensatory mutation than in patients with no protease-compensatory mutations. By covariation and docking analyses, specific mutations were found to affect lopinavir affinity for HIV-1 protease and to impact virological failure. Specifically, the L10V + I13V + L63P + I93L cluster, related to fast virological failure, correlated with a decreased drug affinity for the enzyme in comparison with wild-type (ΔGmut = -30.0 kcal/mol versus ΔGwt = -42.3 kcal/mol). CONCLUSIONS: Our study shows an increased prevalence of specific protease-compensatory mutations in an HIV-1 B-infected population and confirms that their copresence can affect the virological outcome in patients starting a lopinavir/ritonavir-containing regimen.

IP-10 is an additional marker for tuberculosis (TB) detection in HIV-infected persons in a low-TB endemic country.

OBJECTIVE: In Indian HIV-infected patients, IP-10 response to QuantiFERON-TB Gold In tube (QFT-IT) antigens has been associated to tuberculosis (TB). However, specificity for active TB was lower than that reported by QFT-IT, making accuracy for TB detection questionable. To investigate this uncertainty, likely due to India being highly endemic for TB, and to better identify TB correlates, we evaluated the IP-10-based assay in HIV-infected subjects in Italy, a low-TB endemic country. METHODS: 195 individuals were prospectively enrolled; 118 were HIV-infected (21 with active TB, 97 without active TB, and distinguished as high/low-TB-risk). QFT-IT was performed and IP-10 was evaluated by ELISA. RESULTS: Among the HIV-infected individuals, sensitivity for active TB was 66.7% by IP-10-based test and 52.4% (p = 1) by QFT-IT. IP-10-based assay showed a lower dependence on mitogen-response and CD4 counts than QFT-IT. Among subjects without active TB, a higher proportion of IP-10 responders was shown in high-TB-risk subjects than low-TB-risk subjects (40.0% vs 12.9%), similar to QFT-IT (37.1% vs 4.8%). Low-TB risk subjects showed 87.1% specificity for active TB by IP-10-based test vs 95.2% by QFT-IT. CONCLUSIONS: In a low-TB endemic country, besides IFN-γ, IP-10 response to QFT-IT is associated with active TB and TB risk factors in HIV-infected patients with lower dependence on mitogen-response and CD4 counts.