Giacomo Giannini

Vaginal transmission of HIV-1 in hu-SCID mice: a new model for the evaluation of vaginal microbicides.

ObjectiveTo develop an animal model of vaginal transmission of HIV-1 for the evaluation of vaginal microbicides. DesignVaginal infection was performed in SCID mice reconstituted with 4 × 107 human peripheral blood lymphocytes (hu-PBL) by non-invasive vaginal administration. The hu-PBL were previously infected in vitro with a non-syncytium (NSI) strain of HIV-1 (SF162) (hu-PBL-SCID). Lymphocyte migration in vivo was examined using fluorescently labelled human lymphocytes. MethodsThe percentage of CD4 T cells, plasma viral load and p24 antigen were evaluated using fluorescent activated cell sorting (FACS), the Amplicor HIV-1 monitor kit and enzyme-linked immunosorbent assay, respectively. Polymerase chain reaction (PCR) analysis was performed on DNA extracted from spleen and lymph nodes. For in vivo migration of labelled lymphocytes, the mice were sacrified after 4, 24 and 48 h; vaginae and local lymph nodes were removed, snap frozen with OCT, sectioned and examined by fluorescent microscopy and FACS. ResultsHIV transmission was established using virus-infected cells inoculated vaginally, as shown by FACS, HIV viral load, p24 and PCR results. Labelled cells were easily located within the vaginal tissues after 4 h. However, few or no cells could be identified after 24 or 48 h at the vaginal level, whereas labelled cells could be detected at the level of regional lymph nodes. ConclusionsBecause of its simplicity and practical features compared with other animal models, the vaginal HIV-infected hu-SCID mouse model may prove useful to test the activity of compounds against cell-associated HIV and, possibly, other sexually transmitted diseases.

Quality of life outcomes of combination zidovudine- didanosine-nevirapine and zidovudine-didanosine for antiretroviral-naive advanced HIV-infected patients.

ObjectivesTo evaluate the quality of life outcomes in antiretroviral-naive patients randomized to zidovudine plus didanosine versus zidovudine plus didanosine plus nevirapine for treatment of advanced HIV disease (the Istituto Superiore di Sanità 047 trial). DesignA 48-week randomized, double-blind trial. MethodsSixty patients were enrolled and evaluated over 24 weeks. Quality of life was assessed using a modified version of the Medical Outcomes Study-HIV Health Survey. For analysis, we calculated two summary scores reflecting the physical (PHS) and the mental (MHS) components of health. ResultsAlthough the three-drug combination was superior at inducing immunologic and virologic responses, the two-drug regimen was superior for both PHS and MHS, especially at week 8 where differences were both statistically and clinically significant (5.8 and 9.2 points, respectively, P < 0.02 for both). Quality of life changes paralleled trends in body weight and Karnofsky performance status score. ConclusionAlthough a three-drug antiretroviral therapy regimen was superior in terms of short term virologic/immunologic response, the two-drug regimen was better in terms of quality of life. In general, triple therapy remains the most effective treatment option. However, quality of life assessments can yield results that may be discordant with and complementary to those obtained using conventional endpoints. Comparative trials should collect a comprehensive range of outcome measures, including patient-reported quality of life, in order to provide clinicians and patients with additional information that may influence treatment decisions.

HIV phenotype switching during antiretroviral therapy: emergence of saquinavir-resistant strains with less cytopathogenicity.

Objectives:The aim of the study was to investigate changes in virological characteristics of HIV strains isolated from 38 HIV-seropositive subjects during antiretroviral therapy. Design and methods:Patients with a CD4+ cell count ≤ 300 × 106/l were treated with zidovudine (12 individuals) and saquinavir (10 individuals) alone or in combination (16 individuals). CD4+ cell count, viral load, HIV biological phenotype and drug resistance were evaluated during the study period. Results:After 52 weeks, 28 subjects (74%) harboured drug-resistant strains. In patients with a syncytium-inducing (SI) strain, a decline of CD4+ cell count and an increase of viral load were observed aside from the emergence of drug resistance. Conversely, at the emergence of antiretroviral resistance, an immunological and virological deterioration was observed only in patients who had a non-syncytium-inducing (NSI) strain. During the study, a phenotype switching of HIV isolates was detected in eight (21%) patients and a temporal correspondence between the appearance of phenotype switching and the emergence of drug resistance was found in seven cases. Three patients harbouring saquinavir-resistant strains showed a switch from SI to NSI variants associated with a moderate increase in CD4+ cell count. Conclusions:The emergence of resistant strains during antiretroviral therapy may be associated with the selection of viral strains with less cytopathogenicity, while it could become a poor prognostic sign in patients with NSI isolates.

Risk factors and occurrence of rash in HIV-positive patients not receiving nonnucleoside reverse transcriptase inhibitor: data from a randomized study evaluating use of protease inhibitors in nucleoside-experienced patients with very low CD4 levels (<50 cells/microL).

Most of the studies evaluating rash in HIV‐positive patients have focused on nonnucleoside reverse transcriptase inhibitors (NNRTI), particularly nevirapine, and little is known about the occurrence of rash and the risk factors for its development in patients receiving regimens not based on NNRTI.

HIV‐related morbidity and mortality in patients starting protease inhibitors in very advanced HIV disease (CD4 count of < 50 cells/µL): an analysis of 338 clinical events from a randomized clinical trial*

AIDS defining events occur infrequently in the presence of CD4 counts above 200 cells/µL. It is, however, uncertain for most of the AIDS defining conditions whether this threshold can be considered equally safe in patients with a previously very low CD4 nadir.

Plasma HIV-1 copy number and in vitro infectivity of plasma prior to and during combination antiretroviral treatment.

Some studies on untreated patients have shown a general correlation between plasma HIV copy number and plasma infectivity in in vitro models. Recent observations also indicate that HIV-RNA level is an important predictor of perinatal transmission and may also have a role in heterosexual transmission. To further analyse the correlation between HIV viral load and plasma infectivity, we studied the relationship between HIV-1 plasma copy number and plasma infectivity prior to and during treatment with antiretroviral combination regimens in HIV-1 infected adults. Plasma infectivity was assessed in vitro by coculture of plasma from HIV-positive patients with PHA-stimulated fresh PBMC from uninfected donors. A positive plasma isolation, in almost all cases (43/45) and irrespective of treatment status, was associated with an HIV viral load higher than 100000 copies per ml, with higher plasma HIV-1 RNA values in isolation-positive samples compared with isolation-negative samples (median values, 710000 vs. 37500 copies per ml, respectively). SI and NSI strains had similarly high viral load values (470000 vs. 790000 copies per ml), but CD4 counts were lower in the SI phenotype group. Our data indicate that low levels of viral load are only exceptionally associated with isolation from plasma in the in vitro model we used. This observation confirms indirectly the presence of an association between viral load and infectivity. The requisite of a high plasma viral load in order to obtain infectivity (i.e. positivity of HIV isolation from plasma) also seems maintained under antiretroviral treatment, adding confidence in the conclusion that reductions in viral load translate into reduction of plasma infectivity. Due to the extreme complexity of factors determining transmission, a very prudent interpretation of the results is essential when information from experimental studies has to be transferred to clinical situations requiring assessment of risks or clinical decisions.

Hospitalizations and Costs of Treatment for Protease Inhibitor-Based Regimens in Patients with Very Advanced HIV-Infection (CD4 < 50/mm3)

Abstract Purpose: To describe the cost of hospitalization and treatment in patients with very advanced disease who tart different regimens based on a protease inhibitor (PI). Method: An observational retrospective analysis was performed on data from a 48-week randomized, multicenter study. Analysis was based on a subgroup of centers that were geographically defined. Costs of ordinary hospital admissions and of antiretroviral treatment were considered. Incidence of hospitalization and number of days free from hospitalization during the period of observation were calculated. Cost and hospitalization measures were compared among patients receiving three different therapeutic regimens: only PI, PI plus one nucleoside, or PI plus two nucleosides. A multivariate analysis was used to assess cost differences, controlling for variables potentially able to influence outcome. Results: Overall, among 166 patients starting PI (PI plus two nucleosides, 71; PI plus one nucleoside, 65; only PI, 30), 162 ordinary hospital admissions were observed during about 1 year of follow-up. Monthly rates of admission per person and incidence of first hospitalization on 100 person-months showed a clear inverse relationship with the number of drugs comprising the baseline treatment regimen, with the lower rates for the triple therapy group (0.06 and 3.9, respectively), intermediate values for the dual therapy group (0.10 and 8.1, respectively), and higher rates for the PI monotherapy group (0.15 and 13.7, respectively). The average number of days free from hospitalization per month was 29.5 in the triple therapy group, 28.6 in the dual therapy group, and 27.9 in the monotherapy group. The results of cost analysis showed, despite higher cost of antiretroviral treatment, that global costs were progressively lower using regimens of increasing potency: Compared to PI monotherapy, global cost (costs of antiretroviral treatment and of hospitalizations combined) per month per patient was 31.9% lower for the triple therapy group and 19.3% lower for the dual therapy. Global cost for the triple therapy was 15.7% lower compared to global cost for dual therapy. After adjustment for CD4 count, AIDS status, and Karnofsky score, both hospitalization costs and global costs were significantly lower for triple therapy compared to monotherapy (p = .002 and .039, respectively). Conclusion: In advanced and nucleoside-experienced patients, PI-containing regimens have a differential impact according to the overall strength of the regimen, with the best effects on both hospitalizations and treatment costs obtained using PI within potent combination regimens.

A Randomized Trial Comparing the Introduction of Ritonavir or Indinavir in 1251 Nucleoside-Experienced Patients with Advanced HIV Infection

ISS-IP1, a multicenter, randomized, 48-week open trial, was designed to compare the introduction of ritonavir or indinavir in patients with previous nucleoside experience and CD4+ cell counts below 50/mm3. Concomitant antiretroviral treatment with nucleoside analogs was allowed. Primary efficacy measures were survival and time to a new AIDS-defining event or death, analyzed through the whole period of observation by the intention-to-treat approach. Primary toxicity measures were time to treatment discontinuation and adverse events, grade at least 3/serious, analyzed by an on-treatment approach. Evaluation-of efficacy also included CD4+ cell and RNA response. The trial enrolled 1251 patients in 5 months. At baseline, mean CD4+ cell count was about 20 cells/mm3 and mean HIV RNA copy number was 4.9 log10/ml in both groups. Overall, 402 patients in the ritonavir group and 250 patients in the indinavir group permanently discontinued the assigned treatment (relative risk, 1.96; 95% CI, 1.68-2.30; p = 0.0001), with most of this difference dependent on a higher number of discontinuation for adverse events in the ritonavir group. After a mean follow-up of 307 days (ritonavir, 304; indinavir, 309), 124 deaths (ritonavir, 61; indinavir, 63; relative risk, 0.96; 95% CI, 0.67-1.36; p = 0.80) and 330 new AIDS-defining events (ritonavir, 170; indinavir, 160; relative risk, 1.05; 95% CI, 0.85-1.31; p = 0.60) were observed. CD4+ cell counts increased in both groups in patients still receiving treatment, with about 100 cells gained by week 24 and 150 cells gained by week 48. Body weight also increased over time in both groups. Analysis of RNA response showed a decrease of 1.5 log10 or higher in both treatment groups. Overall, 400 patients in the ritonavir group and 338 patients in the indinavir group developed at least one grade 3/serious new adverse event during follow-up (relative risk, 1.48; 95% CI, 1.28-1.72; p = 0.0001). Favorable CD4+ cell and RNA responses at 24 and 48 weeks were observed in both groups of patients remaining on treatment. Indinavir showed slightly better effects in sustaining RNA, CD4+ cell, and body weight responses. Ritonavir and indinavir results were comparable in terms of clinical outcome (survival and AIDS-defining events).