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Stefano Vella

Publications and source records attributed to Stefano Vella.

46 records · Page 3Linked to original sources
PubMed2002

Discordant response to antiretroviral therapy: HIV isolation, genotypic mutations, T-cell proliferation and cytokine production.

OBJECTIVE: To study virologic and immunologic factors associated with discordant treatment response in HIV-infected patients receiving highly active antiretroviral therapy (HAART). DESIGN: Study participants included a total of 27 patients: (a) 10 discordant patients (mean CD4+ cell count, 396.1 x 10 cells/l; mean HIV-RNA, 5.4 log copies/ml); (b) seven responder patients (mean CD4+ cell count, 997.5 x 10 cells/l); and (c) 10 failing patients (mean CD4+ cell count 66.5 x 10 cells/l; mean HIV-RNA, 5.4 log copies/ml).(10) (10) METHODS: The HIV-1 isolation rate and biological phenotype, drug resistance genotypic mutations of HIV-1 strains, recall and HIV-1-specific antigen lymphocyte proliferation (LP), and interleukin (IL)-15 production were studied. RESULTS: Virus isolation was obtained in 30% of discordant patients, and in 100% of failing patients. A higher replication constant was reported in discordant patients. No difference in the number of drug resistance mutations and biological phenotypes of HIV-1 was found in discordant patients with respect to failing patients. Discordant patients developed positive LP responses to and HIV-1 p24. LP in response to, HIV-1 p24 and gp160 was positive in responder patients. No significant LP was found in failing patients. Increased levels of IL-15 after stimulation with lipopolysaccaride (LPS) and were found in both discordant patients and responder patients. Conversely, a strong reduction of IL-15 levels was observed in failing patients. CONCLUSION: The present results suggest that decreased virus isolation rate, restoration of both lymphocyte proliferation and IL-15 production are factors involved in the discordant antiretroviral therapy response of HIV-infected patients.

Adult↗
PubMed2002

In vitro and in vivo modulation of MDR1/P-glycoprotein in HIV-infected patients administered highly active antiretroviral therapy and liposomal doxorubicin.

P-glycoprotein (P-gp) transports a wide range of structurally unrelated drugs, such as HIV protease inhibitors (PIs) and cytotoxic compounds such as anthracyclines. Because modification of P-gp phenotype and function is an important underlying mechanism of drug interactions, the current study was conducted in order to evaluate whether highly active antiretroviral therapy (HAART), HIV plasma viral load (VL), or cancer chemotherapy may induce in vivo changes of P-gp phenotype in peripheral blood mononuclear cells (PBMCs) from HIV-infected treatment-naive and -experienced subjects at different stages of HIV infection and/or disease, including patients with HIV-associated Kaposi sarcoma (KS). Our results show that neither HAART nor HIV VL, nor the stage of HIV infection and/or disease, significantly alter P-gp expression on PBMCs. In particular, surface P-gp expression is expressed at low levels by T-cell subsets, B cells, and NK cells, whereas almost all monocytes are double positive and these results are not modified by HIV PI-containing regimens. By contrast, a significant phenotype modification is detected in PBMCs from AIDS/KS patients after challenge with the liposomal formulation of the anthracycline doxorubicin (L-DOX) with the higher expression reached 24 hours after the end of the drug infusion. In addition, accumulation of L-DOX is unaffected by P-gp-mediated drug efflux as documented by in vitro experiments, in sharp contrast to the kinetic of free DOX, based on HIV PI blockade experiments. Finally, P-gp expression was found in KS spindle cells from HIV-infected treatment-naive AIDS/KS patients. We conclude that P-gp phenotype in PBMCs and specific subsets is not altered by HAART and/or HIV, whereas a significant increase is induced by specific anticancer drugs such as L-DOX. Moreover, HIV PIs possess an inhibitory effect on P-gp function that may improve DOX sensitivity in KS spindle cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2002

Antiretroviral treatment for adult HIV infection in 2002: updated recommendations of the International AIDS Society-USA Panel.

OBJECTIVE: New information warrants updated recommendations for the 4 central issues in antiretroviral therapy: when to start, what drugs to start with, when to change, and what to change to. These updated recommendations are intended to guide practicing physicians actively involved in human immunodeficiency virus (HIV)- and acquired immunodeficiency syndrome (AIDS)-related care. PARTICIPANTS: In 1995, physicians with specific expertise in HIV-related basic science and clinical research, antiretroviral therapy, and HIV patient care were invited by the International AIDS Society-USA to serve on a volunteer panel. In 1999, others were invited to broaden international representation. The 17-member panel met regularly in closed meetings between its last report in 2000 and April 2002 to review current data. The effort was sponsored and funded by the International AIDS Society-USA, a not-for-profit physician education organization. EVIDENCE AND CONSENSUS PROCESS: The full panel was convened in late 2000 and assigned 7 section committees. A section writer and 3 to 5 section committee members (each panel member served on numerous sections) identified relevant evidence and prepared draft recommendations. Basic science, clinical research, and epidemiologic data from the published literature and abstracts from recent (within 2 years) scientific conferences were considered by strength of evidence. Extrapolations from basic science data and expert opinion of the panel members were included as evidence. Draft sections were combined and circulated to the entire panel and discussed in a series of full-panel conference calls until consensus was reached. Final recommendations represent full consensus agreement of the panel. CONCLUSIONS: Because of increased awareness of the activity and toxicity of current drugs, the threshold for initiation of therapy has shifted to a later time in the course of HIV disease. However, the optimal time to initiate therapy remains imprecisely defined. Availability of new drugs has broadened options for therapy initiation and management of treatment failure, which remains a difficult challenge.

Adjuvants, Immunologic↗
PubMed2002

Association of virus load, CD4 cell count, and treatment with clinical progression in human immunodeficiency virus-infected patients with very low CD4 cell counts.

This study prospectively assessed the impact of treatment modality, virus load, and CD4 cell count of <50 cells/mm(3) on human immunodeficiency virus disease progression. The incidence rate of new AIDS disease or death was 54.8 (95% confidence interval, 48.7-59.9) per 100 person-years of follow-up. Independent predictors related to progression were latest CD4 cell count (relative risk [RR], 0.84/10 mm(3) higher; P<.0001), latest hemoglobin level (RR, 0.79/g/L higher; P<.0001), Pneumocystis carinii pneumonia prophylaxis (RR, 0.49; P<.0001), latest body mass index (RR, 0.93/kg/m(2) higher; P=.002), latest virus load (RR, 1.11/log(10) higher; P=.03), and intensity of treatment (RR, 1.82, P=.004; RR 2.27, P<.0001; RR 2.46, P=.0001; RR 2.33 P<.0006; 5.10, P<.0001, respectively, for 4, 3, 2, 1, or no drugs vs. >or=5 drugs). Although reverse causality cannot be excluded, more intense antiviral treatment appears to decrease the risk of progression in immunocompromised patients.

Adult↗
PubMedDate not supplied

[DREAM project early results (drug resources enhancement against AIDS in Mozambique)].

This study is aimed at assessing the outcomes of home care treatment for people living with AIDS in Mozambique. The authors have analysed data from 62 adult patients undergoing a Home Care Program carried out by the Sant'Egidio Community, Italy and the Sue Ryder Care in Matola, Mozambique. The above-mentioned program complies with the WHO guidelines and provides for free antiretroviral therapies and laboratory exams. After hardly two-year treatment, the mortality rate of the sub-sample examined dropped by nearly 80%. Both compliance and adverse reactions have shown to be similar to the reported levels in developed countries. This program is unprecedented in Mozambique and has proved extremely effective for the affected population.

English Abstract↗
PubMedDate not supplied

Treatment for adult HIV infection: 2006 recommendations of the International AIDS Society--USA panel.

CONTEXT: Guidelines for antiretroviral therapy are important for clinicians worldwide given the complexity of the field and the varied clinical situations in which these agents are used. The International AIDS Society-USA panel has updated its recommendations as warranted by new developments in the field. OBJECTIVE: To provide physicians and other human immunodeficiency virus (HIV) clinicians with current recommendations for the use of antiretroviral therapy in HIV-infected adults in circumstances for which there is relatively unrestricted access to drugs and monitoring tools. The recommendations are centered on 4 key issues: when to start antiretroviral therapy; what to start; when to change; and what to change. Antiretroviral therapy in special circumstances is also described. DATA SOURCES AND STUDY SELECTION: A 16-member noncompensated panel was appointed, based on expertise in HIV research and patient care internationally. Data published or presented at selected scientific conferences from mid 2004 through May 2006 were identified and reviewed by all members of the panel. DATA EXTRACTION AND SYNTHESIS: Data that might change previous guidelines were identified and reviewed. New guidelines were drafted by a writing committee and reviewed by the entire panel. CONCLUSIONS: Antiretroviral therapy in adults continues to evolve rapidly, making delivery of state-of-the-art care challenging. Initiation of therapy continues to be recommended in all symptomatic persons and in asymptomatic persons after the CD4 cell count falls below 350/microL and before it declines to 200/microL. A nonnucleoside reverse transcriptase inhibitor or a protease inhibitor boosted with low-dose ritonavir each combined with 2 nucleoside (or nucleotide) reverse transcriptase inhibitors is recommended with choice being based on the individual patient profile. Therapy should be changed when toxicity or intolerance mandate it or when treatment failure is documented. The virologic target for patients with treatment failure is now a plasma HIV-1 RNA level below 50 copies/mL. Adherence to antiretroviral therapy in the short-term and the long-term is crucial for treatment success and must be continually reinforced.

Journal Article↗