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Biomedical subjects

Stefano Rusconi

Publications and source records attributed to Stefano Rusconi.

10 recordsLinked to original sources
PubMed2025

Genomic Epidemiology of the Main SARS-CoV-2 Variants Circulating in Italy During the Omicron Era.

Since early 2022 the Omicron variant has rapidly spread worldwide, becoming the dominant variant to date. The study aimed to investigate the clinical and epidemiological characteristics of COVID-19 patients and reconstruct the genomic epidemiology of main SARS-CoV-2 Omicron sublineages in Italy in 2022. A total of 8970 SARS-CoV-2 samples were studied, and phylogenetic analyses were focused on BA.1, BA.2, and BA.5 subvariants. More than half of subjects received three doses of vaccine and experienced a reinfection. A significant larger proportion of unvaccinated subjects presented reinfection compared with vaccinated. Clusters presented a tMRCA between September-November 2021 (BA.1), November 2021-January 2022 (BA.2), and October 2021-May 2022 (BA.5). Re values showed the highest level between September-October, January-February 2022, and May 2022 for BA.1, BA.2 and BA.5, respectively. Limited number of studied variant sequences are included in clusters. The spread rate of the studied variant exceeded its evolutionary rate. No single sublineage had sufficient time to differentiate into large clusters, but only into small and fragmented groups sharing the same recent ancestor. These analyses dissect the epidemiological dynamics of Omicron sublineages in Italy over a period of great epidemiological changes in the COVID-19 epidemic.

Humans↗
PubMed2003

Processivity and drug-dependence of HIV-1 protease: determinants of viral fitness in variants resistant to protease inhibitors.

OBJECTIVE: To investigate the role of processivity and drug-dependence of HIV-1 protease as fitness determinants in variants resistant to protease inhibitors (PI). DESIGN AND METHODS: HIV-1 protease sequences from 32 infected subjects (27 patients who failed PI-treatments and five PI-naive controls) were evaluated using a recombinant method. The HIV-1 phenotype to seven PI was analysed together with the replication capacity of recombinants and the processivity and drug-dependence of the HIV-1 proteases. Protease mutants (positions 10, 46, 54, 82, 84, 90, and combinations thereof) were generated in vitro and studied under identical experimental conditions. RESULTS: In the absence of PI, 24 of 27 (89%) resistant proteases from treated subjects showed decreased processivity compared with the wild type. Processivity was lower in sequences bearing fewer mutations, than in more mutated ones. Twelve sequences (44%) conferred slower replication kinetics to the recombinant viruses. Seven sequences (26%) showed higher processivity levels in the presence of PI than in their absence, suggesting that drug-dependence influences PI-resistant variants. Among the mutants generated in vitro, mutations 82A and 90M determined broad cross-resistance to PI in association with 10I. A drop of processivity was observed for the 82A+90M variants; 10I allowed partial recovery for 82A and 84V, and marked recovery for 90M mutants. CONCLUSIONS: A decrease in HIV-1 protease processivity parallels early selection of primary mutations, whereas its recovery is driven by compensatory mutations. Furthermore, a PI may select drug-dependent, besides resistant, HIV-1 protease variants. Changes in processivity and drug-dependence of HIV-1 proteases have implications in the replication capacity of PI-resistant viruses.

Cloning, Molecular↗
PubMed2003

Low expression of inhibitory natural killer receptors in CD8 cytotoxic T lymphocytes in long-term non-progressor HIV-1-infected patients.

We investigated whether a different pattern of HLA-specific inhibitory natural killer receptor (iNKR) expression on peripheral blood mononuclear cells (PBMC) of long-term non-progressor (LTNP) patients explained their benign course of HIV-1 infection. The surface expression of p70, p140 and CD94/NKG2A in their CD3+CD8+ PBMC was comparable to that of uninfected donors. The lack of iNKR-mediated functional inhibition of HIV-1-specific cytotoxic T lymphocytes in vitro could provide an additional mechanism for the efficient control of virus spread in LTNP patients.

Adult↗
PubMed2003

Immunovirological outcomes in 70 HIV-1-infected patients who switched to lopinavir/ritonavir after failing at least one protease inhibitor-containing regimen: a retrospective cohort study.

The immunovirological outcome of lopinavir/ritonavir was evaluated in 70 antiretroviral-experienced HIV patients; at baseline, median CD4+ cell count was 218 cells/mm(3) and median plasma viraemia 4.58 log(10) copies/mL. After 12 months, we observed an increase in CD4+ cell count to 322 cells/mm(3) (P = 0.0001) and a decrease in plasma viraemia to 2.35 log(10) copies/mL (P = 0.0001). Four patients discontinued lopinavir/ritonavir during observation. Among metabolic parameters, only triglyceride concentrations increased during treatment (P = 0.02). Twenty-six patients had a genotypic resistance test at baseline; four had > or =6 mutations known to reduce susceptibility to lopinavir/ritonavir. Undetectable plasma viraemia was obtained only in patients with < or =5 mutations (61.9%).

Adult↗
PubMed2003

Tipranavir.

Explore the source record for details and available documents.

Anti-HIV Agents↗
PubMed2003

Alovudine Medivir.

Medivir is developing alovudine, an anti-HIV compound for the potential treatment of drug-resistant HIV infection. A phase IIa trial involving patients with multiresistant HIV was initiated in October 2001 and by July 2002, the trial had been completed.

Clinical Trials, Phase I as Topic↗
PubMed2003

Simplification of protease inhibitor-containing regimens with efavirenz, nevirapine or abacavir: safety and efficacy outcomes.

OBJECTIVE: To describe the immunological and virological outcome, and the factors associated to discontinuation in patients switching to a regimen containing efavirenz (EFV), nevirapine (NVP) or abacavir (ABC) after long-term viral suppression under protease inhibitor-including HAART. DESIGN: Observational study at three outpatient clinics for HIV care in Italy. METHODS: Patients with HIV RNA <80 copies/ml and CD4 >200 cells/ml for at least 6 months on a protease inhibitor-containing treatment who switched to NVP, EFV or ABC were included in the study. End-points were immunological failure, virological failure and discontinuation due to toxicity. Survival analyses were performed to find out any independent variables predictive of reaching the end-points. RESULTS: 177 patients were enrolled; 85 started EFV, 54 NVP and 38 ABC as part of the simplification regimen. 16/159 patients experienced immunological failure: the variables associated to CD4 count decrease were HIV RNA set point value (HR 2.32 for each log10 copies more, P=0.040) and intolerance/toxicity as reason for simplification (HR 3.96, P=0.05). 13/151 subjects showed virological failure; an AIDS diagnosis (HR 6.04, P=0.021) and the use of NVP (HR 7.98, P=0.027) were associated to a worse virological outcome, while patients naive before HAART showed a lower risk of failure (HR 0.008, P=0.007). 16/177 patients discontinued simplification regimen due to toxicity; longer HAART duration before switch was associated to risk reduction (HR 0.92, P=0.004). CONCLUSIONS: Simplification is safe and effective, but it should be offered to patients with shorter treatment duration, and in good clinical and immunovirological conditions.

Alkynes↗
PubMed2003

Virological success of lopinavir/ritonavir salvage regimen is affected by an increasing number of lopinavir/ritonavir-related mutations.

We evaluated the virological outcome of lopinavir/ritonavir (LPV/RTV) in 224 HIV-1-infected and protease inhibitor (PI)-experienced patients showing virological failure to a highly active antiretroviral therapy (HAART) regimen and followed up for at least 3 months. At baseline, the median level of plasma viraemia was 4.61 log10 copies/ml (range 3-6.48) and the median CD4 cell count was 219 cells/mm3 (range 1-836). During a median follow-up of 272 days (range 92-635), we observed an increase in the number of CD4 cells (P=0.02) and a dramatic decrease in plasma viraemia levels (P=0.0001), which became undetectable in 122 patients (54.5%). The closely related predictive factors were baseline plasma viraemia levels and the number of mutations known to reduce susceptibility to LPV/RTV. Thirty-one patients (13.8%) discontinued LPV/RTV during the follow-up, and one AIDS event and three deaths were recorded. Of the 134 patients (59.8%) who underwent a baseline genotype resistance test, 22 (16.4%) had > or = 6 mutations known to reduce LPV/RTV susceptibility; plasma viraemia became undetectable in 76 patients (56.7%), only five of whom harboured > or = 6 mutations at baseline (P=0.0001). The independent predictive factors related to virological success were plasma viraemia levels and the number of mutations reducing susceptibility to LPV/RTV at baseline; each additional log10 copies/ml of HIV RNA reduced the probability of virological success by 34.0% and each extra mutation by 14.5%.

Adult↗
PubMed2002

HIV-1 protease inhibitors in development.

Several pharmaceutical companies have developed an increasing number of second generation protease inhibitors (PI) during the last few years. Many of these compounds have been in preclinical trials and some are now in clinical use. All drugs in this category have been designed to be well absorbed and overcome the crucial problem of cross-resistance within this class of compounds. Taking into account the rapid occurrence of PI cross-resistance, clinicians who are treating patients with the HIV-1 infection will need new active PIs in the near future. The clinical and antiviral efficacy of the new molecules versus the older PIs will be investigated through comparative trials that are likely to be completed over the next 12 months. These third-generation PIs currently in development will be the subject of our review.

Drug Design↗