Gioacchino Angarano

Insights into the reasons for discontinuation of the first highly active antiretroviral therapy (HAART) regimen in a cohort of antiretroviral naive patients

Objective:To evaluate the frequency of discontinuation of the first highly active antiretroviral regimen (HAART) and the factors predictive of discontinuing for toxicity and failure in a population-based cohort of HIV-positive individuals in Italy, naïve from antiretrovirals at enrolment. Methods:The study population consisted of individuals who initiated HAART and had at least one follow-up visit. The primary end-points were discontinuation of any component of HAART for drug toxicity and discontinuation for failure. Survival analyses were performed to identify predictive factors for reaching the two end-points. Results:Eight hundred and sixty-two individuals initiated HAART; in 727 of them (84.3%) this consisted of two nucleoside reverse transcriptase inhibitors (NRTI) and one protease inhibitor (PI). Over a median follow-up of 45 weeks, 312 patients (36.2%) discontinued therapy: 182 (21.1%) discontinued due to toxicity, 44 (5.1%) due to failure. The probability of discontinuing HAART at 1 year was 25.5% [95% confidence interval (CI), 21.9–28.9] due to toxicity and 7.6% (95% CI, 4.9–10.3) due to failure. Independent factors associated with discontinuation for toxicity were: gender [relative hazard (RH) = 0.51; 95% CI, 0.32–0.80 for men versus women], type of treatment (indinavir-containing regimens, RH = 1.94; 95% CI, 1.10–3.41 and ritonavir-containing regimens, RH = 3.83; 95% CI, 2.09–7.03 versus hard-gell saquinavir) and time spent on treatment (RH = 0.89; 95% CI, 0.80–0.98 for each additional month). Discontinuation due to failure was independently associated with the most recent HIV-RNA (RH = 3.20; 95% CI, 1.74–5.88 for log10 copies/ml higher), and with type of treatment (indinavir-containing regimens, RH = 0.21; 95% CI, 0.06–0.78 and ritonavir-containing regimens, RH = 0.23; 95% CI, 0.04–1.26 versus hard-gell saquinavir). Conclusions:If the current HAART regimen caused no toxicity, less than 10% of naïve patients discontinue their first HAART regimen because of failure after 1 year from starting therapy.

Prevalence of Drug-Resistant HIV-1 Variants in Untreated Individuals in Europe: Implications for Clinical Management

BACKGROUND Infection with drug-resistant human immunodeficiency virus type 1 (HIV-1) can impair the response to combination therapy. Widespread transmission of drug-resistant variants has the disturbing potential of limiting future therapy options and affecting the efficacy of postexposure prophylaxis. METHODS We determined the baseline rate of drug resistance in 2208 therapy-naive patients recently and chronically infected with HIV-1 from 19 European countries during 1996-2002. RESULTS In Europe, 1 of 10 antiretroviral-naive patients carried viruses with > or = 1 drug-resistance mutation. Recently infected patients harbored resistant variants more often than did chronically infected patients (13.5% vs. 8.7%; P=.006). Non-B viruses (30%) less frequently carried resistance mutations than did subtype B viruses (4.8% vs. 12.9%; P<.01). Baseline resistance increased over time in newly diagnosed cases of non-B infection: from 2.0% (1/49) in 1996-1998 to 8.2% (16/194) in 2000-2001. CONCLUSIONS Drug-resistant variants are frequently present in both recently and chronically infected therapy-naive patients. Drug-resistant variants are most commonly seen in patients infected with subtype B virus, probably because of longer exposure of these viruses to drugs. However, an increase in baseline resistance in non-B viruses is observed. These data argue for testing all drug-naive patients and are of relevance when guidelines for management of postexposure prophylaxis and first-line therapy are updated.

Premature lesions of the carotid vessels in HIV-1-infected patients treated with protease inhibitors.

ObjectivesTo evaluate the presence of premature atherosclerotic lesions of epiaortic vessels in HIV-1-infected protease inhibitor-(PI) treated patients compared with PI-naive patients and healthy individuals. DesignOne-hundred and two HIV-1-positive patients, including 55 treated with PI for at least 12 months and 47 either naive or treated with PI-sparing regimens, were subjected to epiaortic vessel ultrasonography. These data were compared with those obtained from 104 healthy individuals. MethodsIntima characteristics, pulsation and resistance indexes, and minimal, peak and mean speed were evaluated using a colour power doppler. Atherosclerotic plaques were described. Independent risk factors and values for glycaemia, cholesterolaemia and triglyceridaemia were considered. Statistical analysis included the chi-square test, Mantel–Haenszel test, odds ratio and logistic regression analysis. ResultsOf the PI-treated patients, 29 out of 55 (52.7%) presented acquired lesions of the vascular wall at ultrasonography, whereas similar lesions were found in seven out of 47 (14.9%) PI-naive patients. Of the 104 healthy individuals, seven cases (6.7%) of intimal medial thickness were noted. A slightly significant correlation was found between carotid lesions and age, male sex and hypercholesterolaemia, whereas cigarette smoking, hypertriglyceridaemia and Centers for Disease Control and Prevention stage significantly increased the risk of vascular lesions (P = 0.022, P = 0.017 and P = 0.079 respectively). However, the highest significance regarded use of PI (P = 0.011). These results were confirmed by logistic regression analysis. ConclusionsThese data demonstrate a higher than expected prevalence of premature carotid lesions in the PI-treated compared with PI-naive patients. If confirmed, a periodic ultrasonographic study of the vascular wall should be included in the follow-up of HIV infected patients.

Man-to-woman sexual transmission of HIV: longitudinal study of 343 steady partners of infected men.

To study incidence and risk factors of heterosexually transmitted HIV infection, we followed a cohort of 343 seronegative women, stable, monogamous partners of infected men whose only risk of acquiring HIV was sexual exposure to the infected partner. Nineteen seroconversions occurred in 529.6 person years (py) of observation, yielding an incidence rate of 3.6 per 100 py. The incidence rate was 7.2 per 100 py among women who did not always use or never used condoms and 1.1 among those who always used them [relative risk (RR) 6.6, 95% confidence interval (CI) 1.9-21.9]. Anal sex was associated with a risk increase in only those women not always using condoms (RR 1.4, 95% CI 0.4-4.8). No seroconversions were observed among 22 women using oral contraceptives. One of the women using intrauterine devices seroconverted. In couples who did not always use condoms, seroconversions occurred more frequently in partners of men with symptomatic diseases, with a low CD4+ cell number (< 400 per mm3) or with a detectable p24 antigen. In couples not always using condoms and where the man had a low CD4+ cell count, the joint presence of blood viral antigens and AIDS symptoms conditioned a fivefold increased risk of seroconversion of the woman (RR 5.4, CI 1.4-20.3). At multivariate analysis, women with longer relationships (> or = 1 year) showed a lower risk of seroconversion (RR 0.3, CI 0.1-0.8), and those partners of men positive for p24 antigen in serum had an increased risk of seroconversion (RR = 4.0, CI 0.1-0.8).

Gender differences in antiretroviral drug-related adipose tissue alterations. Women are at higher risk than men and develop particular lipodystrophy patterns.

Adipose tissue alterations (ATAs) were clinically assessed in 2258 HIV-1–infected outpatients consecutively observed in 6 Italian clinical centers and were found to be present in 29.5% of the men and 41.9% of the women. A logistic regression model including age, HIV disease Centers for Disease Control stage, CD4 cell counts, HIV RNA load, the duration of antiretroviral therapy, the number of drugs taken, and the use of d4T showed that men had a 0.47 adjusted risk of presenting with ATAs (95% CI: 0.38–0.58, P < 0.0001). The risks of having ATAs (except circumscribed lipomas) in any body region, presenting with fat accumulation, or being affected by combined forms of ATA were also lower in men, whereas the risk of developing pure lipoatrophy was similar in the 2 genders. Our results indicate that women are at higher risk of developing antiretroviral treatment–related ATAs and show a particular and complex ATA pattern.

Secondary Mutations in the Protease Region of Human Immunodeficiency Virus and Virologic Failure in Drug-Naive Patients Treated with Protease Inhibitor-Based Therapy

The role of mutations in protease (PR) and reverse-transcriptase (RT) of human immunodeficiency virus (HIV) in predicting virologic failure was assessed in 248 antiretroviral-naive HIV-positive patients who began a PR inhibitor-containing antiretroviral regimen. Genotypic testing was performed on plasma samples stored before the start of therapy. Twenty-seven patients (10.9%) had mutations in the RT, 5 (2%) carried primary mutations in the PR, and 131 (52.8%) showed only secondary PR mutations. Virologic failure at week 24 occurred in 62 (25.0%) of 248 patients. There was a statistically significant correlation between virologic failure and the number of PR mutations (P= .04, chi(2) test). Mutations at codons 10 and 36 of PR (present in 39.3% and 40.0% of patients in whom treatment failed, respectively) were identified by stepwise logistic regression as the strongest predictors of virologic failure (odds ratio, 2.20; 95% confidence interval, 1.30-3.75; P= .004). If confirmed in independent studies, this result may justify the increased use of HIV genotyping in drug-naive patients requiring antiretroviral therapy.

Effect of Antiretroviral Therapy on Cryptosporidiosis and Microsporidiosis in Patients Infected with Human Immunodeficiency Virus Type 1

Abstract To better understand whether potent antiretroviral therapies can modify the natural history of HIV-1-associated microsporidiosis and cryptosporidiosis, the response to antimicrobial treatment of these opportunistic infections was evaluated in patients with or without antiretroviral treatment. Fifty patients with diarrhoea, all positive for Cryptosporidium parvum or Enterocytozoon bieneusi, were included in the study. Retrospective data were collected concerning demographics, clinical and microbiological characteristics of the parasitic infection, antiretroviral therapy and prophylaxis against opportunistic infections. Faecal samples were prepared using the Richie formalin-ethyl acetate method and stained using the modified Ziehl-Neelsen method for detection of Cryptosporidium parvum and Isospora belli, the modified trichrome and calcofluor white technique for detection of Enterocytozoon spp., and iodine for detection of ova, cysts or vegetative forms. Diarrhoea was defined as an abnormal increase in stool liquidity, an abnormal increase in stool frequency and a daily stool weight of more than 250 g for a period of at least 4 days. Patients treated with double antiretroviral therapy or protease inhibitors demonstrated an excellent response and a sustained therapeutic effect after follow-up (range, 5–36 months). The relapse of cryptosporidiosis in two patients who discontinued antiretroviral therapy suggests that the infection might remain in a latent stage. The resolution of the diarrhoea seems to be related to an increased CD4+ cell count rather than to the viral load. In conclusion, these data strongly support the hypothesis that combination antiretroviral therapy is able to greatly modify the course of cryptosporidiosis and microsporidiosis in patients infected with HIV-1.

The Calculated Genetic Barrier for Antiretroviral Drug Resistance Substitutions Is Largely Similar for Different HIV-1 Subtypes

Background: The genetic barrier, defined as the number of mutations required to overcome drug-selective pressure, is an important factor for the development of HIV drug resistance. Because of high variability between subtypes, particular HIV-1 subtypes could have different genetic barriers for drug resistance substitutions. This study compared the genetic barrier between subtypes using some 2000 HIV-1 sequences (>600 of non-B subtype) isolated from anti-retroviral-naive patients in Europe. Methods: The genetic barrier was calculated as the sum of transitions (scored as 1) and/or transversions (2.5) required for evolution to any major drug resistance substitution. In addition, the number of minor protease substitutions was determined for every subtype. Results: Few dissimilarities were found. An increased genetic barrier was calculated for I82A (subtypes C and G), V108I (subtype G), V118I (subtype G), Q151M (subtypes D and F), L210W (subtypes C, F, G, and CRF02_AG), and P225H (subtype A) (P < 0.001 compared with subtype B). A decreased genetic barrier was found for I82T (subtypes C and G) and V106M (subtype C) (P < 0.001 vs subtype B). Conversely, minor protease substitutions differed extensively between subtypes. Conclusions: Based on the calculated genetic barrier, the rate of drug resistance development may be similar for different HIV-1 subtypes. Because of differences in minor protease substitutions, protease inhibitor resistance could be enhanced in particular subtypes once the relevant major substitutions are selected.

Augmented Serum Neutralizing Activity against Primary Human Immunodeficiency Virus Type 1 (HIV-1) Isolates in Two Groups of HIV-1-Infected Long-Term Nonprogressors

Neutralizing activity against primary human immunodeficiency virus type 1 (HIV-1) isolates from 17 persons who were long-term disease nonprogressors (LTNPs) and 13 persons who were fast progressors (FPs) was compared. Sera from LTNPs showed higher neutralizing activity both in titer and in host spectrum than did sera from FPs. However, LTNP sera had limited neutralizing activity against HIV-1 subtypes from different geographic areas. Sera collected 6 years earlier from both groups had limited neutralizing activity, indicating that early responses are not predictive for disease progression. LTNPs had very low virus loads, as reflected by only one positive isolation, which was an MT-2-negative phenotype. Virus was isolated from all FPs, and the isolates showed a phenotype switch from MT-2 negative to MT-2 positive. Development of high-titer, broadly cross-reactive neutralizing antibodies is associated with control of virus replication and low virus load in HIV-1-infected LTNPs.

Therapeutic immunization with hiv-1 tat reduces immune activation and loss of regulatory t-cells and improves immune function in subjects on HAART

Although HAART suppresses HIV replication, it is often unable to restore immune homeostasis. Consequently, non-AIDS-defining diseases are increasingly seen in treated individuals. This is attributed to persistent virus expression in reservoirs and to cell activation. Of note, in CD4+ T cells and monocyte-macrophages of virologically-suppressed individuals, there is continued expression of multi-spliced transcripts encoding HIV regulatory proteins. Among them, Tat is essential for virus gene expression and replication, either in primary infection or for virus reactivation during HAART, when Tat is expressed, released extracellularly and exerts, on both the virus and the immune system, effects that contribute to disease maintenance. Here we report results of an ad hoc exploratory interim analysis (up to 48 weeks) on 87 virologically-suppressed HAART-treated individuals enrolled in a phase II randomized open-label multicentric clinical trial of therapeutic immunization with Tat (ISS T-002). Eighty-eight virologically-suppressed HAART-treated individuals, enrolled in a parallel prospective observational study at the same sites (ISS OBS T-002), served for intergroup comparison. Immunization with Tat was safe, induced durable immune responses, and modified the pattern of CD4+ and CD8+ cellular activation (CD38 and HLA-DR) together with reduction of biochemical activation markers and persistent increases of regulatory T cells. This was accompanied by a progressive increment of CD4+ T cells and B cells with reduction of CD8+ T cells and NK cells, which were independent from the type of antiretroviral regimen. Increase in central and effector memory and reduction in terminally-differentiated effector memory CD4+ and CD8+ T cells were accompanied by increases of CD4+ and CD8+ T cell responses against Env and recall antigens. Of note, more immune-compromised individuals experienced greater therapeutic effects. In contrast, these changes were opposite, absent or partial in the OBS population. These findings support the use of Tat immunization to intensify HAART efficacy and to restore immune homeostasis. Trial registration ClinicalTrials.gov NCT00751595