Hairy Cell Leukemia: Preliminary Results with Alpha2 (r) Interferon

Ten patients with hairy cell leukemia are being treated at our institution with a therapeutic schedule of α2(r) interferon (2 × 106 IU/m2 s.c. three times per week). Five patients underwent splenectomy from 4 to 108 months before treatment; nonsplenectomized patients had spleens palpable 6 to 12 cm UCM. According to Quesada's response criteria, at the sixth month of therapy, one patient was considered a complete responder, 8 partial responders and one a minor responder, with no differences between splenectomized and nonsplenectomized patients. In nonsplenectomized patients the spleen returned to normal. Our data confirm that interferon, even at low dosages, is a very effective approach for hairy cell leukemia. No evidence was found to contraindicate such therapy.

In vitro Selection of Human Immunodeficiency Virus Type 1 Resistant to Ro 31-8959 Proteinase Inhibitor

Human immunodeficiency virus type I (HIV-1) resistant to the proteinase inhibitor Ro 31–8959 has been obtained by growing HIV-IIIB in C8166 cell cultures in the presence of inhibitory concentrations of the drug.

Ro 31-8959-resistant HIV-1 obtained after five passages in the presence of the drug was capable of replicating, as measured by infectious virus yield, in the presence of concentrations of Ro 31-8959 able to inhibit completely the replication of the parental HIV-IIIB.

Cloning of the Ro 31–8959-resistant viral preparations revealed that a number of different strains of HIV-1 with various degrees of sensitivity to Ro 31–8959 emerged during propagation of HIV-IIIB in C8166 cells in the presence of the drug. The most resistant strain shows an ID50 value of 21.8 nM that is 13.2 fold higher than the value observed in HIV-IIIB infected C8166 cells.

Drug Combination of AZT and ddl: Synergism of Action and Prevention of Appearance of AZT-Resistance

Both 3′-azido-3′-deoxythymidine (AZT) and 2′,3′-dideoxynosine (ddl) strongly inhibit the replication of human immunodeficiency virus type 1 (HIV-1). Here, it is shown that combination of AZT and ddl at concentrations that are readily achievable in vivo synergistically inhibit HIV-1 replication in C8166 cells and peripheral blood mononuclear cells. The synergism is significant even when the effect of AZT and ddl alone was negligible.

Our findings show that AZT-resistance is less likely to occur when a combination of AZT and ddl is used. Particularly, generation of AZT-resistant strains by in vitro selection is prevented, or delayed, by the combination of AZT plus ddl.

Taken together these observations provide a rationale for combination of AZT and ddl in the therapy of AIDS patients.

What is the practical significance of antibodies to interferons?

Interferons are generally recognised as the treatment of choice in some infectious diseases, such as chronic hepatitis B and C. Since the early clinical trials it was documented that the therapeutic use of interferons could be complicated by the development of antibodies able to neutralise or to bind to the interferon molecule. This finding is not surprising if one considers that natural or therapy-induced antibodies to interleukin (IL)-1, IL-2, IL-6, IL-10, granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, insulin and recombinant factor VIII have been reported in humans. Since hormones, cytokines, biological response modifiers and homeostatic agents are being used for the therapeutic management of many infectious, autoimmune and neoplastic diseases, the possibility that therapy-induced antibodies can develop in humans should be considered. In this article we summarise what is currently known about the clinical significance of antibodies to interferons in interferon-treated patients. The presence of circulating antibodies may affect the response to interferon. Antibody development may be clinically significant, depending on the titre and the time of appearance. In particular, the response to interferon therapy may be affected by antibodies when they appear early in therapy and at high titre.

Markers of human papillomavirus infection and their correlation with cervical dysplasia in human immunodeficiency virus-positive women

Human papillomavirus (HPV) genotypes and HPV DNA load were analysed in cervical smears from 76 human immunodeficiency virus (HIV)-positive and 54 HIV-negative women. The prevalence of genotypes was similar for all women, with the exception of HPV62, which was over-represented in HIV-positive samples. HIV-positive women showed a higher prevalence of multiple genotypes that correlated neither with CD4(+) T-cell counts nor with cervical dysplasia. No significant differences were observed in terms of total or single-type HPV DNA load. The HPV DNA load in both HIV-positive and HIV-negative women was significantly higher in squamous intra-epithelial lesions than in negative Pap smears.

Influence of GBV-C infection on the endogenous activation of the IFN system in HIV-1 co-infected patients

BACKGROUND

GB virus C (GBV-C) co-infection is associated with a better prognosis in HIV-infected persons. Since interferon activation can be one of the possible mechanisms involved in GBV-C-driven protection against HIV, we compared the endogenous activation of the interferon system in PBMC from GBV-C-positive and -negative patients infected with HIV-1.

METHODS

The expression of interferon related genes was analyzed in 20 GBV-C positive and 20 GBV-C-negative HIV-infected patients, comparable in terms of CD4 cell counts and HIV viral loads. The levels of mRNA for interferon-related genes (2-5-OAS, MxA, interferon AR-1 and PKR) in PBMC were measured by real time RT-PCR, using B-actin as internal control.

RESULTS

The endogenous levels of all the Interferon-related genes in HIV/GBV-C co-infected patients were higher than in HIV mono-infected subjects. The difference was statistically significant for PKR mRNA. Direct positive correlation was found between PKR and all the other interferon-related genes, suggesting a coordinated activation of the interferon system.

CONCLUSIONS

Enhanced activation of the interferon system occurs in GBV-C-positive, as compared to GBV-C-negative patients harbouring HIV-1. These data may be relevant to understand the GBV-C-driven protection against HIV, suggesting that the endogenous activation of the interferon system can contribute to the control of HIV replication.

Key questions in antiretroviral therapy: Italian Consensus Workshop (2005)

A panel of leading Italian specialists in infectious diseases, virologists and immunologists met in Rome in 2005 to review critical data and discuss recommendations for each of the key questions in antiretroviral therapy today: When to start treatment? How to start? When to switch? What to switch to? Whether to stop or not to stop treatment, and how? The method of a nominal group meeting was used and recommendations were graded for their strength and quality using a system based on the one adopted by the Infectious Diseases Society of America. Main conclusions are summarized and critically discussed in this consensus statement, as well as some of the most recent data supporting these recommendations are provided.

Evolution of HVR-1 Quasispecies after 1-Year Treatment in HIV/HCV-Coinfected Patients According to the Pattern of Response to Highly Active Antiretroviral Therapy

Hepatitis C virus (HCV) variability is mainly attributed to the ability of the virus to respond to host immune pressure, acting as a driving force for the evolution of quasispecies. This study was aimed at studying the changes in HVR-1 heterogeneity and the evolution of HCV quasispecies in HIV/HCV-coinfected patients according to the pattern of response to highly active antiretroviral therapy (HAART).

Sixteen HIV/HCV-coinfected patients harbouring HCV genotype 1 and who had been on HAART for at least 1 year, 8 showing increasing CD4+T-cell counts (immunological responders) and 8 showing a stable or decreasing CD4+ T-cell counts (immunological non-responders), were selected from a prospective cohort study.

After 1 year of HAART, 11 patients showed HIV viral load <2.6 log10 cp/ml (virological responders), and 5 showed HIV viral load above this value (virological non-responders). Plasma samples, collected before starting therapy and after 1 year of HAART, underwent clonal sequence analysis for HVR-1 region of HCV. Non-synonymous/synonymous substitutions ratio (Ka/Ks), aminoacidic complexity (normalized Shannon entropy) and diversity (p-distance), were considered as parameters of quasispecies heterogeneity. After 1 year of HAART, heterogeneity of HVR-1 quasispecies significantly decreased in virological non-responders, whereas the heterogeneity tended to increase in virological responders. The differences in the evolution were less stringent, when considering immunological response. On the other hand, profound qualitative modifications of HVR-1 quasispecies were observed only in patients with both immunological and virological HAART response.

On the whole, these findings suggest that, in patients undergoing HAART, the extent of HCV variability and the evolution of HVR-1 quasispecies is influenced by the pattern of response to antiretroviral therapy.

Considerations on the development of serum antibodies to interferon-beta

The phenomenon of antibodies to interferon (IFN) beta in patients with multiple sclerosis has attracted the attention of numerous research groups over the years, and has been examined from various different points of view. In this review we describe and discuss some of the aspects that we believe to be most worthy of consideration. The main considerations are as follows: There is a lack of substantial information on the biological/immunological phenomenon of neutralising antibodies in vivo development. Nevertheless, sufficient experimental data are available to provide a rationale for monitoring the presence of anti-IFN antibodies in patients treated with IFN beta; A standardised quantitative assay to detect antibody to IFNs must be agreed. Only when results can be compared, both in terms of the qualitative presence and quantitative measurement of antibodies, will it be possible to monitor fully the ability of antibodies to cause a relapse during treatment; Although there is increasing evidence to indicate that the development of antibodies to IFN beta may be associated with a failure of the beneficial effects of the therapy, the use of the seropositivity for neutralising antibodies to IFN beta as the only surrogate marker for clinical and therapeutic decision-making is questionable.

Cell membrane proteins and quasispecies compartmentalization of CSF and plasma HIV-1 from aids patients with neurological disorders

Cell membrane protein (CMP) profile of HIV-1 from cerebrospinal fluid (CSF) and plasma of five AIDS patients with neurologic disorders was analyzed and compared with viral quasispecies composition in these body compartments. To this aim, paired CSF and plasma samples from AIDS subjects with HIV-related neurological diseases (three HIV-1 encephalopaty (HIVE) and two primary CNS lymphoma (PCNSL)) underwent immobilized antibody capture (IAC) assay to determine the profile of CMP acquired by HIV-1. The considered CMPs were CD45RO, CD26, CD36, glut-R, N-CAM, VCAM-1, ELAM-1, CD44 and CD58, representing lymphomonocyte, neuronal and adhesion molecules. Cloning and sequencing of env and gag regions was performed to predict coreceptor usage and to analyze quasispecies compartmentalization. The results indicated that CD44 and CD58 were the most represented molecules on HIV-1 from CSF, whereas CD36 was the most abundant molecule on plasma HIV-1. V3 env aminoacidic sequences and net charge were consistent with M-R5 phenotype in all CSF and in most plasma clones. The degree of genetic heterogeneity (both complexity and diversity) in p17 gag was significantly lower in CSF-HIV than that in plasma-HIV for three patients, higher for one patient, and not significantly different for one patient, suggesting compartmentalization for all but the latter patient. When considering the pattern of CMP, the most abundant CMP observed in HIV from plasma and CSF was different in patients showing compartmentalization, while was the same in the patient without significant differences in CSF and plasma quasispecies. In conclusion, the present data on CMP pattern, V3 loop aminoacidic signature and genetic heterogeneity of HIV-1 quasispecies from CSF and plasma of HIVE patients, are consistent with a compartmentalized virus replication, at least in some patients, and with a possible different source of HIV in the two body sites, even though in a context of a largely prevalent M-R5 phenotype.

Response to Haart and Gb Virus Type C Coinfection in a Cohort of Antiretroviral-Naive HIV-Infected Individuals

The prognostic role of GB virus type C (GBV-C) viraemia in HIV-infected subjects treated with highly active antiretroviral therapy (HAART) is still undefined, The aim of this analysis is to assess the relationship between GBV-C infection and response to antiretroviral therapy among HIV-infected subjects initiating HAART when antiretroviral-naive.

A prospective, observational study of 400 HIV-infected patients with measurements of GBV-C RNA, hepatitis C virus (HCV) antibodies and HCV RNA determined from plasma stored prior to HAART initiation, Time to virological (achieving HIV RNA ≤500 copies/ml) and immunological success (a CD4+ count increase of ≥200cells/μl), and the time to virological relapse (confirmed HIV RNA >500 copies/ml) were assessed by Kaplan-Meier methods and Cox proportional hazard regression model.

Of the subjects, 117 (29.3%) were GBV-C positive and, overall, 351 (87.8%) patients achieved virological success, After controlling for a number of confounders including HCV RNA, GBV-C viraemic patients experienced a significantly lower risk of HIV rebound than those who were GBV-C negative [relative hazard (RH)=0.56, 95% CI: 0.34–0.93, P=0.03], Conversely, the probability of achieving initial virological success or CD4+ count response after HAART did not differ between GBV-C-negative and -positive subjects, These results suggest that GBV-C coinfection may play a role in determining the rate of HIV rebound possibly by competing with HIV replication after HIV load has been successfully suppressed by HAART.

Increased sensitivity of SARS-coronavirus to a combination of human type I and type II interferons

There is currently an urgent need to identify effective antiviral agents that will prevent and treat severe acute respiratory syndrome coronavirus (SARS-CoV) infection. In this study, we have investigated and compared the antiviral effect of different interferons (IFNs) on SARS-CoV replication in the epithelial kidney monkey Vero cell line. The results showed that SARS-CoV grown in Vero cells is moderately sensitive to IFN-beta and only weakly sensitive to IFN-alpha and IFN-gamma, in comparison to other IFN-sensitive viruses, such as those for encephalomyocarditis, vesicular stomatitis and Newcastle disease. Simultaneous incubation of Vero cells with IFN-beta and IFN-gamma indicated that they may act synergistically against SARS-CoV replication. The IFN-induced MxA protein was detected in the IFN-treated Vero cells. The data, however, suggest that the antiviral activity of IFN against SARS-CoV virus is independent of MxA expression.

Increased Sensitivity of Sars-Coronavirus to a Combination of Human Type I and Type II Interferons

There is currently an urgent need to identify effective antiviral agents that will prevent and treat severe acute respiratory syndrome coronavirus (SARS-CoV) infection. In this study, we have investigated and compared the antiviral effect of different interferons (IFNs) on SARS-CoV replication in the epithelial kidney monkey Vero cell line. The results showed that SARS-CoV grown in Vero cells is moderately sensitive to IFN-β and only weakly sensitive to IFN-α and IFN-γ, in comparison to other IFN-sensitive viruses, such as those for encephalomyocarditis, vesicular stomatitis and Newcastle disease. Simultaneous incubation of Vero cells with IFN-β and IFN-γ indicated that they may act synergistically against SARS-CoV replication. The IFN-induced MxA protein was detected in the IFN-treated Vero cells. The data, however, suggest that the antiviral activity of IFN against SARS-CoV virus is independent of MxA expression.

Variability in the Interpretation of Transmitted Genotypic HIV-1 Drug Resistance and Prediction of Virological Outcomes of the Initial Haart by Distinct Systems

High level HIV-1 drug resistance in recently infected treatment-naive individuals correlates with sub-optimal virological responses to highly active antiretroviral therapy (HAART). To determine whether genotypic HIV-1 drug resistance in chronic naive patients, as interpreted by various systems, could predict the virological outcomes of HAART, isolates from patients enrolled in a prospective observational cohort (ICoNA) prior to treatment start were genotyped. Genotypic susceptibility scores (GSS) assigned to the initial HAART regimens using the interpretations of pre-therapy resistance mutations by 13 systems were related to virological outcomes. Of 415 patients, 42 (10%) had at least one major resistance mutation. According to the different interpretations, 1.9–20.5% of patients had some level of resistance to at least one drug in the initial regimen. In multivariable analysis, GSS from two systems significantly predicted the time to virological success: Rega 5.5, for each unit increase in GSS adjusted relative hazard (RH) 1.86 [95% confidence intervals (95% CI): 1.15–3.02] and hivresistanceWeb v3, RH 1.87 (95% CI: 1.00–3.48). With three other systems, GSS showed a trend towards a significant prediction of success: Retrogram 1.6, RH 2.33 (95% CI: 0.98–5.53), Menéndez 2002, RH 2.36 (95% CI: 0.97–5.72) and Stanford hivdb, RH 2.06 (95% CI: 0.94–4.49). Genotypic resistance testing coupled with adequate interpretation in chronic naive patients can usefully identify those at risk of sub-optimal virological response to HAART.

The Management of Hepatitis B Virus/HIV-1 Co-Infected Patients Starting Their First Haart Regimen. Treating Two Infections for the Price of One Drug?

We examined the impact of a lamivudine-containing highly active antiretroviral therapy (HAART) regimen on 164 hepatitis B virus/HIV co-infected individuals starting their first HAART. Lamivudine-treated patients (accounting for 73% of the study population) showed a significantly lower level of alanine aminotransferase over follow-up [–81.1 mU/ml mean difference; 95% confidence intervals (95% CI): –30.3; –131.7, P=0.003] and a significantly reduced risk of liver-related morbidity/mortality [Relative hazard (RH)=0.07; 95% CI: 0.01–0.38, P=0.002] than those starting a lamivudine sparing-regimen.

Serum interferon (IFN)-neutralizing antibodies and bioactivities of IFNs in patients with severe type II essential mixed cryoglobulinemia

The efficacy of alpha interferon (IFN-alpha) in the treatment of severe type II essential mixed cryoglobulinemia (EMC) has been reported previously. In some patients, the development of neutralizing antibodies to recombinant IFN-alpha (rIFN-alpha) can affect the clinical response achieved with rIFN-alpha; a second treatment with natural IFN-alpha preparations may reinduce the clinical response. In the present study the ability of leukocyte IFN (LeIFN) to restore the response was investigated from a pharmacodynamic viewpoint. Specifically, the pharmacodynamic profiles of different IFN-alpha preparations were studied by measuring the serum neopterin levels and the levels of expression of protein MxA mRNA in in vivo peripheral blood mononuclear cells in two patients with EMC whose resistance to rIFN-alpha2a treatment increased concomitantly with the development of neutralizing antibodies. These markers were measured before injection and at 24 and 48 h after a single injection of rIFN-alpha2a, consensus IFN [(C)IFN], or LeIFN. No increase or only a slight increase in MxA mRNA levels was detectable after administration of rIFN-alpha2a or (C)IFN, whereas a significant increase (>/=10-fold) in MxA mRNA expression was recorded following administration of LeIFN. The neutralizing antibodies to rIFN-alpha2a cross-react with (C)IFN. Sera from these patients neutralized most but not all of the subtypes present in the natural IFN-alpha (LeIFN) mixture, and no significant increase in neopterin levels was observed after these patients were switched to LeIFN treatment. In summary, the data demonstrate that the problem of neutralizing antibodies still exists and that LeIFN may induce an increase in the level of MxA mRNA expression but not an increase in neopterin levels in patients who are resistant to treatment with rIFN-alpha2a or (C)IFN.

Is human immunodeficiency virus RNA load composed of neutralized immune complexes?

During acute human immunodeficiency virus (HIV) infection, both virus load (HIV RNA) and infectivity are high (10(3)-10(7) RNA copies/mL or TCID(50)/mL) until antibody is produced, which may reduce the HIV infectivity. In HIV carriers, the HIV RNA load is elevated (10(3)-10(5) copies/mL), but infectivity is low (10(0)-10(2) TCID(50)/mL). The low infectivity in carriers could be due to neutralization by antibody in serum, resulting in immune complexes (ICs). We demonstrated that ICs in plasma, prepared with protein A beads, contained HIV RNA (80%-100%) in association with immunoglobulin G (IgG). In comparison, ICs from patients with acute HIV infection and little or no antibody contained virtually no HIV RNA. Moreover, ICs prepared by ultrafiltration contained IgG and specifically and irreversibly neutralized HIV, which indicates that the ICs contained neutralizing antibody. These findings indicate that the HIV RNA in the plasma of carriers is frequently composed of antibody-neutralized HIV as ICs.

Decay of HIV type 1 DNA and development of drug-resistant mutants in patients with primary HIV type 1 infection receiving highly active antiretroviral therapy

The present study was aimed at describing the effect of highly active antiretroviral therapy (HAART) in 10 patients with primary HIV infection (PHI). Clearance rates of HIV RNA and HIV DNA in peripheral blood as well as the preexistence and the emergence of drug-resistant strains of HIV were determined over 52 weeks of treatment. The data indicate that HAART is able to induce a suppression of plasma viral load together with a significant decrease, but not a suppression, of peripheral blood mononuclear cell-associated proviral DNA in PHI subjects. Analysis of drug-resistant strains revealed that three PHI patients, showing a complete virologic response, developed mutations in the pol gene, thus suggesting that a persistent residual virus replication exists despite a sustained suppression of plasma viremia.

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.

Changes in host cell molecules acquired by circulating HIV-1 in patients treated with highly active antiretroviral therapy and interleukin-2

OBJECTIVE

To analyse cell membrane proteins (CMP) acquired by HIV-1 present in the plasma of asymptomatic patients, and their modifications after a cycle of highly active antiretroviral therapy (HAART) and interleukin (IL)-2.

DESIGN AND METHODS

Plasma samples from eight drug-naive asymptomatic subjects underwent immobilized antibody capture (IAC) to detect CMP on the surface of circulating HIV-1. The CMP considered were lymphocyte subset markers (CD45RA, CD45RO), activation markers (HLA-DR), adhesion molecules (LFA-3), costimulatory proteins (B7-2), lymph-node homing receptors (CD62L) and pro-apoptosis molecules (FasL). This analysis was repeated after one cycle of HAART + IL-2, after virus rebound.

RESULTS

LFA-3, followed by CD45RO and HLA-DR, are the most represented CMP on the surface of circulating virions in naive asymptomatic patients; CD45RA, CD62L, B7-2 and FasL are detected only occasionally. After rebound, a significant reduction of CD45RO and HLA-DR, but not of LFA-3, is observed on virions, whereas CD45RA and CD62L, as well as other molecules, are not affected, remaining almost undetectable.

CONCLUSIONS

Assuming that CMP on HIV-1 reflect the cellular origin of virions, activated T cells expressing CD45RO, HLA-DR, and LFA-3 may be the main source of HIV-1 in asymptomatic patients. After a cycle of HAART + IL-2, followed by therapy interruption, CD45RA and CD62L are detected on virions rarely, indicating that even during virus rebound, expanded naive T cells do not become a major target of virus replication. Furthermore, the presence of HLA-DR on rebound HIV-1 is decreased, consistent with decreased activation of the HIV-producing cells. More extensive investigation may clarify the significance of these findings with respect to pathogenesis.

Activation of signal transduction and apoptosis in healthy lymphomonocytes exposed to bystander HIV-1-infected cells

Persistent activation of the immune system is one of the hallmarks of HIV-1 infection. In this study we analysed the induction of factors involved in cytokine signal transduction, such as STAT 1 proteins and IRF-1 mRNA, in normal peripheral blood mononuclear cells (PBMC) exposed to HIV-infected cells, and the induction of apoptosis. Western blot analyses and reverse transcriptase-polymerase chain reaction results indicate that both cells infected with a X4 strain and cells infected with a R5 strain are able to increase intracellular levels of STAT 1alpha and beta proteins as well as IRF-1 mRNA. This effect was prevented by neutralizing antibodies against interferon-alpha (IFN-alpha). HIV-1-infected cells dose-dependently induced apoptotic commitment in normal PBMC, as revealed by DNA fragmentation analysis, but this was not accompanied by an increase of caspase-3 activity, even if a slight up-regulation of IL-1beta-converting enzyme mRNA was detected. Apoptosis induction could be abrogated mainly by antibodies against tumour necrosis factor-alpha (TNF-alpha) and, to a lesser extent, by antibodies against IFN-gamma. All these findings suggest that uninfected PBMC can undergo activation of signal transduction and apoptosis after exposure to bystander HIV-infected cells, subsequent to the induction of cytokines such as IFNs and TNF-alpha.

Cellular factors involved in the induction of resistance of HIV to antiretroviral agents

Long-term treatment of HIV-1 infected patients with antiretroviral agents may result in failure of therapy due to the emergence of resistant virus mutants with decreased susceptibility to the therapeutic agents. Several authors have asked whether cellular factors, other than viral mutation may contribute to the declining efficiency of chemotherapy including nucleoside analogues and protease inhibitors (PI). Prolonged treatment with AZT may induce a defect of thymidine kinase activity in vitro and in vivo. Long-term treatment with other nucleoside analogues, such as d4T and 3TC, is also able to induce in host cells, a decreased sensitivity to the antiviral activity of these compounds. It is suggested that antiviral activity of PI could be modified by the expression of a protein P-gp that has been demonstrated to be able to bind PI and is involved in extrusion of anticancer agents.

Plasma viral load concentrations in women and men from different exposure categories and with known duration of HIV infection. I.CO.N.A. Study Group

CONTEXT

According to recent studies, women have lower plasma HIV RNA concentrations than men. However, these studies did not take into account the duration of HIV infection.

OBJECTIVES

To analyze the relationship between viral load and gender among individuals with known date of seroconversion.

SETTING

Sixty infectious disease clinics in Italy.

DESIGN

Cross-sectional analysis of data collected at enrollment in a cohort study.

PARTICIPANTS

Injecting drug users and heterosexual contacts naive to antiretroviral therapy at enrollment (245 men; 170 women).

MAIN OUTCOME MEASURES

Plasma HIV RNA concentrations, measured using quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) or signal amplification b-DNA assays before antiretroviral therapy.

RESULTS

Plasma HIV RNA concentrations were similar by age and exposure category (p =.80 and p =.39, respectively). Median viral load among women was roughly half that of men (p =.002). The association between viral load and gender remained significant after fitting a two-way analysis of variance (p =.03) and after adjusting for CD4 count, modality of HIV transmission, and age at enrollment in a regression model. Viral load was 0.27 log10 copies/ml (95% confidence interval, 0.05-0.40; p =.01) lower in women (i.e., 50% lower in the raw scale).

CONCLUSIONS

Plasma HIV RNA concentrations were found to be lower among women, even when considering the duration of HIV infection. Compared with men, it is possible women should be given highly aggressive antiretroviral therapy at lower HIV-RNA concentrations.

Anti-HIV antiviral activity of stavudine in a thymidine kinase-deficient cellular line

Stavudine (d4T) is a potent inhibitor of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase. It is known that stavudine is metabolized in cells to the mono-, di- and triphosphate nucleotides but the enzymes responsible for its phosphorylation are as yet unidentified. In particular, there are conflicting results concerning the role of thymidine kinase 1 (TK1) in stavudine metabolism. To gain new insights into this phenomenon we analysed the antiviral activity of stavudine in a TK1-deficient, resistant cell line. The results indicate that TK1 is responsible for the phosphorylation of stavudine but it is not the only enzyme involved in its activation. The other enzyme(s) that might be involved in the metabolism of stavudine, however, are not able to phosphorylate stavudine with the same efficiency as TK1. Since it has been shown that prolonged treatment with zidovudine may induce an in vivo defect in TK1 activity, it is tempting to speculate that patients treated for a long time with zidovudine could be resistant to further treatment with stavudine.

The number of HIV DNA-infected mononuclear cells is reduced under HAART plus recombinant IL-2. IRHAN Study Group

It is common opinion that, in addition to potent antiretroviral regimens which effectively reduce plasma viremia, new strategies should be developed to ensure the reduction of cell-associated HIV DNA load together with HIV RNA plasma levels. The present study explored whether the number of provirus-infected cells can be reduced by combined antiviral and immunomodulatory regimens. Thus, 14 naive patients (with CD4 > 400/microl and plasma HIV RNA copies > 5000/ml) were randomly assigned to receive highly active antiretroviral therapy (HAART) alone or HAART plus rIL-2. Plasma viremia (measured by a commercial RT-PCR assay) and the number of provirus-infected cells (measured by an endpoint cell dilution PCR assay) were monitored at the enrollment and after 12 weeks of treatment. The results indicate that while HAART and HAART plus rIL-2 are both able to significantly reduce plasma viremia after 12 weeks of treatment, a significant reduction of the number of provirus-infected cells can be achieved only by treatment with HAART plus rIL-2.

Significant reduction in HIV-1 plasma viral load but not in proviral infected cells during sub-optimal antiretroviral therapy

Attempts to eradicate HIV infection through highly active antiretroviral therapy (HAART) in the very early stages of the infection have failed due to the resumption of viral replication from unknown reservoirs. It has been postulated that antiretroviral therapy capable of suppressing viral replication, as shown by reduction of HIV-RNA copies in plasma and lymph nodes, should have less effect on the number of HIV-DNA carrying cells in the same districts. To test this hypothesis, plasma viremia and the proportion of provirally infected cells in peripheral blood and in lymph nodes were measured in patients at 3 and 6 months of treatment with zidovudine plus lamivudine. All patients showed a significant decrease in plasma viremia at 3 months that was maintained at 6 months (mean values of 1.6 +/- 0.6 log10 from baseline). Conversely the proportion of HIV-DNA carrying cells slightly declined at 3 months but remained substantially stable thereafter both in peripheral blood and in lymph nodes. Taken together these data suggest that this therapeutic regimen, although sub-optimal, is effective in significantly reducing the virus production by productively infected cells but does not seem to substantially affect the load of provirally infected cells.

Effects of the human CD38 glycoprotein on the early stages of the HIV-1 replication cycle

CD38 displays lateral association with the HIV-1 receptor CD4. This association is potentiated by the HIV-1 envelope glycoprotein gp120. The aim of this work was to evaluate the CD38 role in T cell susceptibility to HIV-1 infection. Using laboratory X4 HIV-1 strains and X4 and X4/R5 primary isolates, we found that CD38 expression was negatively correlated to cell susceptibility to infection, evaluated as percentage of infected cells, release of HIV p24 in the supernatants, and cytopathogenicity. This correlation was at first suggested by results obtained in a panel of human CD4(+) T cell lines expressing different CD38 levels (MT-4, MT-2, C8166, CEMx174, Supt-1, and H9) and then demonstrated using CD38 transfectants of MT-4 cells (the line with the lowest CD38 expression). To address whether CD38 affected viral binding, we used mouse T cells that are non-permissive for productive infection. Gene transfection in mouse SR.D10.CD4(-).F1 T cells produced four lines expressing human CD4 and/or CD38. Ability of CD4(+)CD38(+)cells to bind HIV-1 or purified recombinant gp120 was significantly lower than that of CD4(+)CD38(-) cells. These data suggest that CD38 expression inhibits lymphocyte susceptibility to HIV infection, probably by inhibiting gp120/CD4-dependent viral binding to target cells.-Savarino, A., Bottarel, F., Calosso, L., Feito, M. J., Bensi, T., Bragardo, M., Rojo, J. M., Pugliese, A., Abbate, I., Capobianchi, M. R., Dianzani, F., Malavasi, F., and Dianzani, U. Effects of the human CD38 glycoprotein on the early stages of theHIV-1 replication cycle.

Further study on the specificity and incidence of neutralizing antibodies to interferon (IFN) in relapsing remitting multiple sclerosis patients treated with IFN beta-1a or IFN beta-1b

The development of neutralizing antibodies (NAbs) to interferon (IFN) is a common phenomenon of IFN beta therapy for relapsing-remitting multiple sclerosis (RRMS) patients. Here we examine the specificity of NAbs developed during therapy for RRMS with recombinant interferon (rIFN) beta-1a or rIFN beta-1b, and study the effect of switching from rIFN beta-1a to rIFN beta-1b on the incidence and specificity of NAbs. The relative ability to neutralize rIFN beta-1a and beta-1b was assayed in sera positive for NAbs derived from RRMS patients treated with either rIFN beta-1a (N=9) or rIFN beta-1b (N=16), while the incidence and specificity of NAbs to IFN beta developed during therapy were studied in 50 RRMS patients who were treated for two years with rIFN beta-1a followed by a further year either switching to rIFN beta-1b (N=34) or continuing treatment with rIFN beta-1a (N=16). The results show that all positive sera, independent of the source, may recognize both forms of rIFN beta and that a further year of treatment does not significantly affect the incidence and specificity of the NAbs developed during the first two years of treatment even if treatment is switched to a different type of IFN beta. The data then suggests that it is unlikely that the administration of rIFN beta-1b to anti-rIFN beta-1a NAbs-positive patients can overcome the inhibitory effect exerted by the serum antibodies (and vice versa), and that a further period of treatment with IFN beta-1b in patients previously treated with rIFN beta-1a does not significantly change the pattern of antibody response to IFN beta.

Development of antibodies to interferon beta in patients: technical and biological aspects

There are now several papers describing the development of antibodies to interferons (IFN) in patients undergoing IFN therapy. Moreover, there is increasing evidence to indicate that the development of antibodies to IFN may be associated with a failure of the beneficial effects of the therapy. This paper will review and discuss what is currently known about the technical, and biological aspects of antibodies to IFN, with particular reference to antibodies to IFN beta that develop during therapy. Three main considerations arise from the data. Firstly, a standardized quantitative assay to detect antibody to IFN must be agreed upon. Only when results can be compared, both qualitatively and quantitatively, will it be possible to monitor fully the ability of antibodies to cause a relapse during treatment. Secondly, sufficient data are now available to provide a rationale for monitoring the presence of anti-IFN antibodies in patients treated with IFN. This approach may allow a better understanding of the disease reactivation state observed in numerous patients treated with IFN. Finally, approaches aimed at limiting the immunogenicity of IFN preparations and/or strategies designed to circumvent antibody-mediated resistance to IFN treatment are required.

Antigenic characterization of recombinant, lymphoblastoid, and leukocyte IFN-alpha by monoclonal antibodies

To gain more insight into similarities of different interferon-alpha (IFN-alpha) species, we evaluated neutralization and immunoactivity of a variety of IFN preparations with various monoclonal antibodies (IFN-alpha mAb). Nine IFN-alpha mAb obtained through immunization with recombinant IFN-alpha (rmAb), lymphoblastoid IFN-alpha (LY mAb), and leukocyte IFN-alpha (LE mAb) were tested. The IFN-alpha mAb were evaluated for their ability to neutralize the antiviral activity of 11 recombinant IFN-alpha subtypes, two recombinant IFN-alpha hybrids, and lymphoblastoid and leukocyte IFN-alpha preparations. The same IFN-alpha mAb were also used in immunoblotting, and some of them were used in immunoaffinity chromatography. The results of the neutralization assay reveal that the IFN-alpha mAb significantly differ in their ability to neutralize the individual IFN-alpha species. Interestingly, none of the IFN-alpha mAb was able to neutralize all the IFN-alpha species. In particular, rmAb were unable to neutralize LE-IFN-alpha or LY-IFN-alpha, whereas LE mAb and LY mAb efficiently neutralized rIFN-alpha2. In some cases, the epitopes to which IFN-alpha mAb are directed were identified through the use of synthetic fragments of IFN-alpha2 or by evaluating the selectivity in binding to IFN-alpha subtypes.

RANTES stimulates cell-mediated transmission of HIV-1 infection

We wished to determine the effects of the beta-chemokine RANTES in an established system of cell-mediated transmission of HIV-1, that is, normal human umbilical vein endothelial cells (HUVEC) nonproductively infected with HIV-1, cocultivated with CD4+ T cells to rescue productive infection. The results indicate that the addition of RANTES to HUVEC, either before or after HIV-1 infection, stimulates HIV-1 rescue by CD4+ T cells. However, viral DNA is not increased in HUVEC, suggesting that the stimulation exerted by RANTES could be mediated by events following HUVEC infection. The mechanisms of increase seem to be related to the rescue phase, involving membrane interaction of abortively infected HUVEC with permissive T cells. In fact, a strong upregulation and polarization of intercellular adhesion molecule-1 (ICAM-1) is induced in HUVEC by RANTES, and antibodies against ICAM-1 inhibit HIV-1 rescue by T cells. These results indicate that RANTES, similarly to other inflammatory cytokines, may favor HIV-1 spreading and crossing of blood-tissue barriers by indirect mechanisms involving membrane interactions between nonproductively infected and permissive cells.

Correlation of interferon-induced expression of MxA mRNA in peripheral blood mononuclear cells with the response of patients with chronic active hepatitis C to IFN-alpha therapy

MxA, a protein with selective activity against certain viruses, is an accepted specific indicator of type I interferon (IFN) activity. We have developed an internally controlled quantitative-competitive PCR to measure the amounts of MxA mRNA expressed in peripheral blood mononuclear cells (PBMC). This assay is more sensitive, quantitative, and easily applied to serial clinical samples than previously described methods. We have applied this assay retrospectively to 27 patients with chronic active hepatitis C given IFN-alpha2. Most such patients gain no sustained benefit but nevertheless suffer from the side effects, expense, and inconvenience of the treatment. Fourteen of the 27 had been classified on clinical grounds as responders and 13 as nonresponders at the end of a 6 month treatment period. We measured MxA mRNA in PBMC obtained before and after 8 weeks of IFN-alpha2 treatment. All the patients expressed some level of mRNA before treatment began, and after 8 weeks of treatment, the level rose in 19. This increase was significant (p < 0.001) only in patients classified as responders. This strongly suggests that hepatitis C virus (HCV) patients who express increased amounts of MxA mRNA in their PBMC during IFN-alpha treatment are most likely to obtain long-term benefit. If this finding is confirmed in future prospective studies, it will provide an extremely important predictive marker for managing IFN-alpha therapy in patients with HCV.

Effects of IFN alpha on late stages of HIV-1 replication cycle

IFN alpha causes a modest reduction of HIV-1 expression in chronically infected monocytoid U937 cells. However, the ratio between cell-associated and shed viral p24 antigen is altered, being the cell-associated fraction dose-dependently enhanced by IFN. Furthermore, a significant decrease of infectivity of both cell-associated and shed material is observed. Transmission electron microscopy of IFN-treated cells revealed virus assembly being strongly inhibited, with the production of morphologically altered (tear-drop shaped) virus particles. Proteolytic processing of gag proteins appeared to be normal in IFN-treated cultures. However, virions shed from IFN-treated cells showed a markedly reduced incorporation of virus-specific gp120 and cell-derived ICAM-1 by the virus envelope. Additionally, these particles showed a significantly decreased ability to become bound to CD4+ target cells, accounting for, at least in part, the observed decrease of infectivity. Taken together, the data suggest that, in chronically infected cells, IFN alpha can affect late stages of HIV-1 replication, by inhibiting virus assembly and release, and by reducing the infectivity of shed virions. The latter effect seems to be due, at least in part, to altered incorporation of surface glycoproteins and defective particle formation. The relationship between impaired gp120 incorporation and altered morphogenesis of HIV-1 virions is under investigation.

Development of neutralizing antibodies in patients with relapsing-remitting multiple sclerosis treated with IFN-beta1a

Sixty-eight patients with relapsing-remitting multiple sclerosis (RRMS) were treated with 3 million or 9 million i.u. of recombinant interferon-beta1a (recIFN-beta1a) s.c. three times a week for 2 years. Their sera were tested for antibodies neutralizing the IFN (NAb) in a bioassay. Sera with titers > or = 1:20 were considered positive. We detected NAb in 3.2%, 13.8%, and 15.9% of the patients in sera obtained at 3, 6, and 24 months, respectively. The incidence was not related to the IFN dose. Interestingly, during the 6 month baseline period before the start of the study, relapse rates, baseline disability, and the volume of lesions on T2-weighted images were significantly higher in patients who developed NAb during treatment. Because of interpatient variability, no definitive relationship was observed between NAb formation and loss of clinical or magnetic resonance imaging (MRI) response.