The use of trough ribavirin concentration to predict sustained virological response and haematological toxicity in HIV/HCV-co-infected patients treated with ribavirin and pegylated interferon.

OBJECTIVES: To study the association between trough ribavirin concentration (C(trough)) with sustained virological response (SVR) and haemoglobin (Hb) decrease in HIV/hepatitis C virus (HCV)-co-infected (HIV+/HCV+) patients treated with anti-HCV therapy. METHODS: HIV+/HCV+ patients treated with ribavirin and pegylated interferon were prospectively evaluated. Qualitative and quantitative HCV-RNA, Hb levels and ribavirin C(trough) were measured at baseline and weeks 2, 4, 12, 24, 36 and 48 during therapy. HCV-RNA was also measured at 24 weeks after the end of therapy. Efficacy analysis was performed on patients with a definitive virological outcome (SVR, relapser and non-responder), whereas for toxicity analysis, dropouts were considered until the last available observation. RESULTS: Fifty-two patients (54.7% with genotype 1 or 4) were included. Overall, no correlation between ribavirin C(trough) and early virological response (EVR) nor SVR was found. However, in patients with genotype 1 or 4, ribavirin C(trough) was independently associated with EVR (P = 0.036) and SVR (P = 0.046). A ribavirin C(trough) cut-off of 1600 ng/mL was found to be associated with both EVR (chi(2) = 5.69, P = 0.028) and SVR (chi(2)=4.2, P = 0.04). Higher ribavirin C(trough) correlated with Hb decrease (R = -0.361, P = 0.009) and was independently associated with an Hb decrease of >4 g/dL (P = 0.009). Receiver operating characteristic (ROC) analysis indicated that a ribavirin C(trough) of >2300 ng/mL was associated with an Hb decrease of >4 g/dL (chi(2) = 8.08, P = 0.01). CONCLUSIONS: Our study confirmed a relationship between ribavirin exposure and both efficacy and toxicity. Moreover, we found ribavirin C(trough) cut-offs for both SVR in genotypes 1 and 4 and overall haematological toxicity. These findings deserve further clinical evaluation.

Antiretroviral activity of pegylated interferon alfa-2a in patients co-infected with HIV/hepatitis C virus.

OBJECTIVES: To evaluate the early anti-HIV activity of pegylated interferon (PEG-IFN) alfa-2a and ribavirin in HIV/hepatitis C virus (HCV) co-infected patients not receiving antiretroviral therapy. PATIENTS AND METHODS: In 19 patients with baseline plasma HIV load (HIV-RNA) >1000 copies/mL treated with PEG-IFN alfa-2a and ribavirin, HIV-RNA and T-cell subsets were measured at baseline and 2, 4 and 12 weeks after initiation of anti-HCV therapy. RESULTS: We observed a significant HIV-RNA decrease (>1 log(10) copies/mL) through week 12 of anti-HCV treatment. The magnitude of HIV-RNA decline was associated with baseline HIV-RNA, CD4 count and PEG-IFN weight-adjusted dose. CONCLUSIONS: A significant early anti-HIV activity of PEG-IFN alfa-2a was observed. Such an effect warrants further clinical evaluation in the management of co-infected patients.

Penetration of didanosine in semen of HIV-1-infected men.

OBJECTIVES: The disposition of antiretroviral agents into genital tissue and fluids is one of the factors implicated in the control of viral replication within the male genital tract and should be an objective of highly active antiretroviral therapy. We have investigated didanosine penetration in seminal plasma of 16 HIV-infected patients. PATIENTS AND METHODS: A total of 16 patients on didanosine (200 mg every 12 h or 400 mg once daily) participated in the pharmacokinetic study. After the didanosine morning dose, peripheral blood plasma and semen plasma were collected within the intervals 0-4, 4-8 and 8-12 h in the twice-daily regimen and 0-4, 4-12 and 12-24 h in the once-daily regimen. RESULTS: Within each sampling time interval didanosine concentrations in seminal plasma were higher than in blood. The interquartile range of concentrations in seminal plasma was 292-1217 ng/mL, compared with 50-150 ng/mL in blood plasma. Didanosine could be detected in 14 of the 16 semen samples analysed and in 8 of the 16 blood samples. CONCLUSIONS: We have demonstrated that didanosine penetrates into the seminal plasma in higher concentrations than in blood plasma.

Nevirapine plasma exposure affects both durability of viral suppression and selection of nevirapine primary resistance mutations in a clinical setting.

The relationship between nevirapine plasma concentrations and the durability of both viral suppression (VS) and selection of nevirapine primary resistance mutations (PRMs) was evaluated. A nevirapine trough concentration (Ctrough) of >4,300 ng/ml was found to predict longer VS. Patients with nevirapine Ctrough s ranging from 3,100 to 4,300 ng/ml had higher probabilities of developing PRMs than those with nevirapine Ctrough s below and above this concentration interval.

Longitudinal analysis of the 90K glycoprotein in the Italian HIV-seroconversion study: temporal trend and predictability of the maturity of HIV infection.

OBJECTIVES: To evaluate the level of 90K as a predictor of AIDS; to describe 90K levels over time after HIV serconversion; and to evaluate the 90K level as a marker of the maturity of infection. DESIGN: Prospective incident cohort of HIV-infected individuals with documented dates of seroconversion. METHODS: Cox models were applied to estimate the crude and adjusted relative hazards (RH) of AIDS by level of 90K. Regression models were applied to describe the temporal trend and the correlates of the level of 90K over time after HIV-seroconversion. Logistic models were applied to evaluate the probability of a sample of 90K having been taken within a certain time period after HIV-seroconversion. RESULTS: The study population consisted of 150 participants of the Italian Seroconversion Study. A total of 429 measurements of 90K were taken. Both early and later measurements of 90K were highly predictive of AIDS, also when adjusting for CD4 lymphocyte count and HIV load. The 90K level (U/ml) increased by 10% annually (95% CI: 7%-13%); the increase over time was linear. IDUs had higher 90K levels than heterosexuals and homosexuals over the course of HIV disease. High 90K levels were highly predictive of distant seroconversions (age-adjusted probability, 74%), whereas were poorly predictive of recent seroconversions (age-adjusted probability, 5%); the results were similar for the predictability of CD4 lymphocyte count. CONCLUSIONS: The level of 90K is a useful prognostic tool for clinical purposes. As a marker of the maturity of infection, 90K is similar to the CD4 lymphocyte count, with the advantage of being able to use serum instead of fresh whole blood. It has a good capacity to identify distant infections.

Clinical pharmacology of antiretroviral therapy.

Antiretroviral therapy represents by all means a new branch of anti-infective chemotherapy, and in order to describe the mode of action of antiretrovirals, a series of inferences from anti-bacterial chemotherapy were made. The currently available antiretroviral agents can be classified as time-dependent drugs, and therefore the key pharmacokinetic parameter adopted in their clinical-pharmacological assessment is the concentration at the end of the dosing interval (Ctrough). By focusing on this parameter, the application of Therapeutic Drug Monitoring (TDM) allows for the successful individual tailoring of the drug dosage in some clinical circumstances, such as treatment of drug-resistant infections, drug-drug interactions and side effects. While this procedure has now been sufficiently standardized for protease inhibitors (PIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs), no clinical applications are yet recognized for nucleoside/nucleotide reverse transcriptase inhibitors (N/NtRTIs) and fusion inhibitors. The main unfavourable peculiarity of HIV infection, such as the need for lifelong treatment, is one of the reasons why increasing attention is being paid to pharmacological aspects of antiretroviral therapy. Issues like treatment potency, maintenance over time of the immunovirological benefit and long-term side effects require intensive pharmacological investigation in order to obtain the information on which basing the most convenient strategy to be adopted for the therapeutical management of this condition.

Culture proven Legionella pneumophila pneumonia in a HIV-infected patient: case report and review.

We report the first culture proven case of Legionella pneumonia in a HIV-positive patient in Italy. The laboratory diagnosis was obtained by isolation of Legionella pneumophila serogroup 1, serology, urinary antigen detection and PCR. Culture first allowed diagnosis of the infection, that probably would have been unrecognized. Since Legionellosis in HIV-positive patients with respiratory symptoms is rare and difficult to confirm, we strongly suggest that all available laboratory tests, and particularly culture, should be performed. A review of literature on culture proven cases is also provided.

Successful simplification of HAART in patients with acute primary HIV infection.

Aggressive treatment has been advocated for the management of primary HIV infection (PHI), but the composition and the optimal duration of therapy are still to be determined. In addition, time to undetectable viral load (VL), rate and duration of VL suppression as well as subsequent therapeutic choices remain issues widely debated. We evaluated the rate and duration of VL suppression in 12 consecutive patients with PHI given triple-drug treatment with zidovudine, lamivudine and indinavir (highly active antiretroviral therapy, HAART) at onset of the acute illness and subsequently switched to a simplified 2-NRTI-based regimen once VL suppression was maintained for at least 6 months. Throughout the study, no patient discontinued treatment because of symptoms attributed to the study medications. In the study population, undetectable VL was achieved after a median of 84 days (range: 67-135) on HAART and was maintained for a median of 194 days (range: 179-205) before simplification. After switching to simplified maintenace, undetectable VL was maintained in all patients for at least 6 months. Only one patient experienced virological failure, plasma HIV-RNA remaining suppressed for a median foliow-up of 33 months (15-54) and T-CD4+ being steadily higher than 500/mL in the remaining patients. Our results suggest that simplification of HAART in patients promptly treated during PHI and maintaining undetectable VL for at least 6 months before simplification may be a valid option capable of controlling viral replication and maintaining an optimal immunological profile for a prolonged time.

Response to highly active antiretroviral therapy according to duration of HIV infection.

OBJECTIVE: To evaluate whether duration of HIV-1 infection influences the response to highly active antiretroviral therapy (HAART). DESIGN: Prospective study of individuals (Italian Seroconversion Study cohort) with well-estimated dates of HIV-1 seroconversion. METHODS: This analysis included 277 participants who began HAART (defined as three antiretroviral drugs used in combination). Cox regression models were used to evaluate the association between duration of infection (as categorical variable [7.5 years from seroconversion] or continuous variable) and an immunologic (rise in CD4 count >100 cells/mm3) and a virologic (decline in plasma HIV-RNA to unquantifiable levels) outcome. All analyses were stratified by center of recruitment and adjustment, when used, was for gender, age at inception of HAART, injection drug use, previous antiretroviral therapy, lag-time between positive and negative HIV test result, year of starting HAART, clinical stage, CD4 count, and HIV-RNA at time of HAART. RESULTS: HAART was initiated a median of 6.4 years after seroconversion. There was a median follow-up of 1.6 years after starting HAART to the calendar cut-off (November 1999). One-hundred-eighty-one (65.3%) patients experienced a decline in viral load to below quantifiable levels and 184 (66.4%) experienced a rise in CD4 >100 cells/mm3. In the Cox models, by 1-year increase in duration of infection, we estimated a lower crude hazard of achieving a CD4 count increase >100 cells (relative hazard [RH], 0.96; 95% confidence interval [CI], 0.92-1.01; p =.09), and a lower hazard of reaching an unquantifiable level of plasma HIV-RNA (RH, 0.97; 95%CI, 0.93-1.02; p =.20). After adjustment, these values became 0.99 (95%CI, 0.93-1.04; p =.62) and 0.98 (95%CI, 0.93-1.04; p =.48), respectively. When duration of HIV infection was considered as a categorical variable, the results were consistent with those already described. CONCLUSIONS: These results suggest that the duration of HIV infection does not seem to play an important independent role in determining the virologic and immunologic responses to HAART.

A case of flare syndrome.

The authors describe a case of severe CMV retinitis in a young adult AIDS patient who recovered following first a course of ganciclovir and then HAART. Six months after the initial episode while still under successful HAART, the patient developed an acute episode of retinitis despite a persistent significant improvement in the immunological picture and a very low level of CMV reactivation. The acute episode can be related to an enhanced individual reactivity to minor CMV replication.

Lung carcinoma in 36 patients with human immunodeficiency virus infection. The Italian Cooperative Group on AIDS and Tumors.

BACKGROUND: The current study describes the clinicopathologic characteristics of 36 patients with lung carcinoma and human immunodeficiency virus (HIV) infection observed within the Italian Cooperative Group on AIDS and Tumors (GICAT). METHODS: Patients with lung carcinoma and HIV infection collected by the GICAT between 1986-1998 were evaluated retrospectively. As a control group, the authors analyzed 102 patients age < 60 years with lung carcinoma but without HIV infection who were seen at the CRO, National Cancer Institute, Aviano, Italy between 1995-1996. RESULTS: Patients with lung carcinoma and HIV infection were younger (38 years vs. 53 years) and previously smoked more cigarettes per day (40 vs. 20) than the control group. The main histologic subtype was adenocarcinoma. TNM Stage III-IV disease was observed in 53% of the patients. The median CD4 cell count was 150/mm(3). The median overall survival was significantly shorter in the patients with HIV compared with the control group (5 months vs. 10 months; P = 0.0001). CONCLUSIONS: The results of the current study demonstrate that lung carcinoma in the HIV setting affects mainly young individuals with a history of heavy tobacco smoking and a moderately advanced immunodeficiency status. Lung carcinoma is associated with a more adverse outcome in HIV patients and represents the cause of death in the majority of these patients.

Extracellular activity in Cryptococcus neoformans strains isolated from AIDS patients and from environmental sources.

Nineteen Cryptococcus neoformans strains isolated from AIDS patients and 16 from bird droppings were tested for their extracellular activity. Typical enzymatic activity that was different from other medically important yeasts was found. The results obtained may indicate that there are new extracellular enzymatic activities that imply a relationship between C. neoformans and its virulence. A correlation among the different enzymatic activities was also investigated and according to the results obtained no relationship was observed among any of the recorded extracellular enzymatic activities. Research on C. neoformans extracellular enzymatic activity is useful not only to better understand its metabolism but in particular to establish a possible relationship between its virulence and pathogenicity.

Antiretroviral therapy in HIV-infected individuals in clinical practice: are the criteria for initiating and choosing the type of drug regimen based only on immunologic and virologic values?

OBJECTIVES: To determine factors associated with beginning antiretroviral therapy and with the number of drugs used. METHODS: Longitudinal study of 3169 HIV-infected individuals naïve from antiretroviral drugs at enrollment in 65 infectious disease clinics in Italy. Initiation of antiretroviral therapy and number of drugs used (i.e., < 3 vs. > or = 3 drugs) were the main outcome measures. Adjusted odds ratios were calculated by logistic models to establish cofactors of these two measures. RESULTS: From January 1997 to December 1998, 1288 (40.6%) individuals started therapy, 58.0% of whom were given a triple combination regimen. This regimen became more frequent over time. By multivariate analysis, high levels of HIV-RNA and low CD4 counts were the most important independent predictors of starting any type of therapy. A significant association was also found with HIV exposure category, reason for being antiretroviral-naïve, presence/absence of liver disease, presence/absence of a new AIDS-defining disease, and clinical centre. High levels of HIV-RNA and low CD4 counts were also the most important predictors of starting with > or = 3 drugs, compared to < 3 drugs, and men had an independent higher probability of starting with > or = 3 drugs, compared to women. The probability of starting with > or = 3 drugs significantly increased with calendar time. CONCLUSIONS: CD4 and HIV-RNA were the main cofactors of initiating both any type of therapy and therapy with > or = 3 drugs. The large variability among clinical centres suggests that clinicians are uncertain as to the exact timing of beginning therapy and the specific regimen, especially among women.

Therapy of non-small-cell lung cancer (NSCLC) in patients with HIV infection. GICAT. Cooperative Group on AIDS and Tumors.

Incidence and mortality of AIDS patients have significantly declined in the developed countries due to the very active anti-HIV combination therapy available today. Because of the prolongation of the survival expectancy of these patients, other non-AIDS defining tumours have been recently reported in several cohort studies with increased frequency. We want to report the clinico-pathological features and the outcome of 39 patients with lung cancer and HIV infection, collected by the Italian Cooperative Group on AIDS and Tumors (GICAT) between 1986 and December 1997. As a control group, we decided to evaluate patients, less than 60 years of age, with lung cancer but without HIV infection seen at the CRO, Aviano, during 1995 and 1996. The median age of the study group patients was 38 years (range 28-58) and 90% of them were males. Sixty-nine percent of patients were intravenous drug users and HIV infection was asymtomatic in 41% of patients. NSCLC was observed in 78% of patients, SCLC in 13% and mesothelioma in 8%. Among NSCLC, adenocarcinoma was the most frequently observed histological subtype (48%). No differences were found as regards the stage of disease at diagnosis and the histologic subtype in comparison with the control group. The median overall survival was significantly shorter for patients with HIV infection when compared to that of the control group (5 months vs. 10 months, P < 0.0001). In conclusion, the outcome of patients with SNCLC and HIV infection seems worse than that of the general population, suggesting a synergistic and/or addictive adverse effect of HIV on the outcome of lung cancer.

Temporal changes in the rate of progression to death among Italians with known date of HIV seroconversion: estimates of the population effect of treatment. Italian HIV Seroconversion Study (ISS).

OBJECTIVE: To evaluate changes in survival among HIV-positive individuals with known date of seroconversion (SC). DESIGN: Prospective cohort study. METHODS: Follow-up lasted from SC to death or to the end of 1997. A multivariate Cox model was applied to estimate relative hazards (RH) of death. The year of SC (as a categoric fixed variable) and calendar year (as a time-dependent variable) were considered to evaluate, respectively, cohort and prevalent changes in the rate of death. A separate Cox model was used to assess the association between survival and new combination therapies, using an "intention to treat" approach. RESULTS: The study included 1535 individuals (53.9% injecting drug users, 25.3% homosexuals, 19.5% heterosexuals); 75.8% seroconverted between 1980 and 1991, and 24.2% seroconverted between 1992 and 1997. When adjusting for year of SC, the RH of death (and that of AIDS) was significantly lower in 1997, compared with before 1991 (RH = 0.54; 95% confidence interval, 0.30-0.98). Adjusted RHs of death were significantly lower for combination antiretroviral therapy, compared with no therapy. When combining the two Cox models, the 1997 reduction in risk of death was largely due to antiretroviral therapies; similar results were obtained when the endpoint was AIDS. CONCLUSIONS: A reduction in the risk of death, probably due to combination antiretroviral therapy, was observed in 1997 after having adjusted for age at SC and year of SC.

Longitudinal human immunodeficiency virus type 1 load in the italian seroconversion study: correlates and temporal trends of virus load.

A prospective study of 149 human immunodeficiency virus type 1 (HIV-1) seroconverters was conducted to describe trends and correlates of HIV-1 load after seroconversion and over time. HIV-1 load was quantified from frozen sera by reverse transcriptase-polymerase chain reaction. High early virus load was associated with lower CD4 cell counts and male sex but not with age at seroconversion or injection drug use. Early virus load predicted progression to clinical AIDS and AIDS/<200 CD4 cells/microL. Virus load exhibited a decline of 52% by 18 months after seroconversion then increased 23% annually (95% confidence interval, 13%-33%). Men and those developing AIDS during follow-up had higher virus loads over the course of disease. Persons who developed AIDS had a steeper virus load slope than those who were AIDS-free (P=.01). In long-term follow-up, virus load exhibited a gradual and sustained increase over time. Virus load and annual increase are strong predictors of disease progression.

Longitudinal analysis of serum chemokine levels in the course of HIV-1 infection.

OBJECTIVES: To investigate the correlation between the serum levels of the CC-chemokines RANTES, macrophage inflammatory protein (MIP)-1alpha and MIP-1beta, and the progression of HIV-1 disease. DESIGN: Retrospective analysis of serial serum samples from HIV-1 seroconverters selected according to clinical outcome. METHODS: Twenty-one patients, derived from a cohort recruited between 1985 and 1996 for a prospective study of the natural history of HIV infection, were analysed. All patients had at least one HIV-1-seronegative sample within 1 year prior to the first seropositive test and were followed longitudinally throughout the course of HIV-1 infection (mean follow-up, 73.5 months). Nine were rapid progressors (RP; patients who developed AIDS within 60 months of antibody seroconversion), seven were slow progressors (SP; patients who developed AIDS after 60 months), and five were long-term asymptomatic (LTA; patients with circulating CD4+ cells higher than 400 x 10(6)/l, no signs of HIV disease, no antiretroviral therapy for more than 96 months). A total of 339 serum samples was studied (mean, 16.1 per patient). The levels of RANTES, MIP-1alpha and MIP-1beta were measured by enzyme-linked immunosorbent assay and correlated with different immunological and clinical parameters. RESULTS: Over the entire follow-up period, the geometric mean of serum RANTES was significantly higher in RP [68.6 ng/ml; 95% confidence interval (CI), 56.9-82.7] than in SP (23.7 ng/ml; 95% CI, 20.0-28.2; P < 0.001) and LTA (19.5 ng/ml; 95% CI, 15.5-24.5; P < 0.001). This difference was already significant during the early clinical stages, when patients had peripheral blood CD4+ cell counts still greater than 400 x 10(6)/l (P < 0.001). By contrast, the mean serum levels of MIP-1alpha and MIP-1beta did not differ significantly between the three study groups. Multivariate analysis using the Cox proportional hazard model demonstrated that the mean serum concentration of RANTES before the development of AIDS was independently associated with the time to AIDS (relative risk, 4.5; 95% CI, 1.1-18.2; P = 0.035). In patients with low versus high mean serum RANTES before the fall of CD4+ cells below 400 x 10(6)/l, the median AIDS-free time was 117.5 and 42.7 months, respectively (P = 0.037). CONCLUSION: These data suggest that an elevation of serum RANTES predicts a rapid progression of the disease since the early stages of HIV-1 infection.