Diego Ripamonti

Similar Adherence Rates Favor Different Virologic Outcomes for Patients Treated with Nonnucleoside Analogues or Protease Inhibitors

BACKGROUND This prospective study verified the effect of adherence on the risk of virologic failure. METHODS At enrollment in the study, a total of 543 patients who were following a steady (duration, >or=6 months) and effective (viral load, <50 human immunodeficiency virus [HIV] RNA copies/mL) regimen of highly active antiretroviral therapy (HAART) completed a self-reported questionnaire derived from the Adult AIDS Clinical Trials Group Adherence Follow-up Questionnaire. Patients were followed up for the subsequent 6 months to document virologic failure, which was defined as 2 consecutive viral load measurements of >500 HIV RNA copies/mL. RESULTS Only the type of treatment and the adherence rate at baseline were significantly associated with the virologic end point. Among patients who reported an adherence rate of <or=75%, the rate of virologic failure was 17.4%; this rate decreased to 12.2% for patients whose adherence rate was 76%-85%, to 4.3% for patients whose adherence rate was 86%-95%, and to 2.4% for patients whose adherence rate was >95%. When analysis was adjusted according to the type of regimen received, patients who were receiving protease inhibitor (PI)-based HAART and who had an adherence rate of up to 85% had a virologic failure rate of >20%, whereas, only for patients who were receiving nonnucleoside reverse-transcriptase inhibitor (NNRTI)-based HAART and who had an adherence rate of <or=75%, the virologic failure rate was >10%. For the comparison of NNRTI-treated patients and PI-treated patients with an adherence rate of 75%-95%, the odds ratio was 0.157 (95% confidence interval, 0.029-0.852). The number of pills and daily doses received correlated with the reported adherence rate. CONCLUSIONS Patients receiving NNRTIs report a higher rate of adherence than do patients receiving PIs. Adherence is significantly influenced by the number of pills and daily doses received. Low adherence is a major determinant of virologic failure; however, different therapies have different cutoff values for adherence that determine a significant increment of risk.

Effect of prolonged discontinuation of successful antiretroviral therapy on CD4 T cells: a controlled, prospective trial

Objective: To compare continuous highly active antiretroviral therapy with a CD4 cell count-driven structured treatment interruption (STI) strategy. The primary end-point was the proportion of subjects maintaining CD4 cell count > 400 × 106 cells/l. Secondary end-points were to identify the dynamic and predictive variables of CD4 cell loss. Methods: The BASTA study is a randomized, controlled, prospective trial. Patients with CD4 cell counts > 800 × 106 cells/l were enrolled and the immunological threshold to resume therapy was set to the lower normal limit of CD4 cells for HIV-uninfected adults. Results: Sixty-nine patients were randomized and followed for 64 weeks. At baseline, all had undetectable plasma HIV RNA and their mean CD4 cell count was 1077 × 106 cells/l. None of the patients showed a disease progression or any AIDS-defining event. At each time point, the proportion of subjects in the STI group that had a CD4 cell count < 400 × 106 cells/l was not statistically different from the control group. In all cases, the 95% confidence interval for this difference was smaller than ±10%. However, 57% of patients with nadir CD4 cell count 200–350 × 106 cells/l reached a CD4 cell count < 400 × 106 cells/l. This was statistically different (P = 0.02) from the nearly 90% of patients with a nadir CD4 cell count 350–500 × 106 cells/l who maintained a CD4 cell count of > 400 × 106 cells/l. Conclusions: Prolonged STI in patients with fully suppressed virus and marked immune reconstitution is generally safe. The main predictor of CD4 cell decline is the nadir CD4 cell count. Pulse therapy warrants further careful prospective evaluation to investigate virological and clinical outcomes over a very long period.

Severe hepatotoxicity during combination antiretroviral treatment: Incidence, liver histology, and outcome

Objectives: To assess incidence, risk factors, histology, and outcome of severe hepatotoxicity (SH) during antiretroviral treatment (ART). Methods: Seven hundred fifty‐five HIV‐seropositive patients consecutively prescribed new ART were selected. Liver function tests were assessed at baseline, after 1 month, and every 4 months thereafter. Liver biopsy was recommended in case of SH (i.e., increase in liver enzymes ≥10 times the upper limit of normal or 5 times baseline if markedly abnormal). Results: Twenty‐six cases of SH were observed with an incidence of 4.2% personyears. Liver failure (LF) was rarely seen (1.1 per 100 person‐years). Liver damage was invariably observed in patients with chronic viral hepatitis. Liver histology showed exacerbation of viral hepatitis in all 16 patients for whom a liver biopsy was available at the time of SH. A direct correlation was found between alanine aminotransferase increase and increase in CD4+ T‐cell count in patients with SH (r = 0.53, p < .001). Death occurred during follow‐up in 7 of 26 (27%) patients, all of whom showed LF and baseline CD4+ count less than 200 cells/mm3 (7/7 patients = 100% vs. 8/19 patients without LF; p < .01). Relapse of SH was observed after ART was recommenced in 7 of 17 (41%) patients. Five of these 7 patients did not show further SH relapse after treatment with interferon. Conclusions: This study provides estimates of SH and LF in a large populationbased setting where hepatitis C virus coinfection is highly prevalent and provides indications that liver damage may be caused by immune reconstitution and related exacerbation of viral hepatitis. A strict follow‐up for hepatotoxicity is mandatory when ART is initiated in patients with <200 CD4+ T cells/mm3. Antihepatitis pre‐ or comedication could be an effective preventive or curative measure.

Atazanavir plus low-dose ritonavir in pregnancy: pharmacokinetics and placental transfer.

Background:Adequate antiretroviral exposure during pregnancy is critical to prevent the vertical transmission of HIV and for maternal health. Pregnancy can alter drug kinetics. We assessed the pharmacokinetics of atazanavir/ritonavir (300/100 mg a day) during pregnancy. Methods:An intensive steady-state 24-h pharmacokinetic profile of atazanavir was performed in the third trimester of pregnancy and postpartum. Maternal and umbilical cord blood samples were obtained at delivery. We measured atazanavir by reverse-phase high-performance liquid chromatography. Results:Seventeen women completed the study. Antepartum, the atazanavir geometric mean area under the plasma concentration-time curve from 0 to 24 h (AUC0–24) was 28 510 ng·h/l, the maximum observed plasma concentration (Cmax) was 2 591 ng/ml and the 24-h postdose concentration (Ctrough) was 486 ng/ml. The same postpartum parameters were 30 465 ng·h/l, 2 878 ng/ml and 514 ng/ml, respectively. The antepartum to postpartum ratio for AUC0–24 was 0.94 and for Ctrough was 0.96, indicating equivalence, whereas Cmax values were slightly although not significantly lower. The ratio of cord blood/maternal atazanavir concentration in 14 paired samples was 0.13. Conclusion:Atazanavir exposure during the third trimester of pregnancy is similar to that observed in the non-pregnant period. Over the whole dosing interval, therapeutic drug concentrations well above the wild-type HIV 90% inhibitory concentration are maintained. Atazanavir crosses the placenta, potentially providing further protection for the newborn. As pregnancy does not appear to alter atazanavir exposure, no dose adjustment is required in pregnant women. Results suggest that atazanavir is a reasonable component of HAART during pregnancy.

Factors associated with the failure of HIV-positive persons to return for scheduled medical visits

Abstract PURPOSE: To assess in an HIV-positive cohort the cumulative probability of failing to return for scheduled medical visits and to address the factors associated with follow-up discontinuation. METHOD: This was a hospital-based cohort study conducted from January 1985 through September 1999. Out of 3,300 HIV-1 infected patients, 1,680 patients with CD4 count <500 cells/mL or with AIDS diagnosis were included in the analysis because they received scheduled medical visits for follow-up at our center. Baseline visit was the first visit when patients met the criteria for enrollment. The main outcome measure was failure to return for scheduled medical visits for at least 12 consecutive months. RESULTS: The probability of returning decreased rapidly in the first months after the baseline visit. After 1 year since enrollment, 25% of patients failed to return and after 2 years 34% of patients failed to return. Most patients who failed to return for visits (78%) discontinued their follow-up within 6 months since enrollment. In multivariate analysis, patients in the intravenous drug use (IDU) category were most likely to fail to return for scheduled appointments, as were patients with higher CD4 count (CD4 >50 cells/μL) or patients without AIDS diagnosis. Patients with shorter follow-up had a higher risk of failing to return (odds ratio [OR]: 0.12, 0.36, 0.45, and 0.74 for >36, 24-36, 12-24, and 6-12 months of follow-up respectively vs. <6 months). Patients who were enrolled in more recent years had a higher compliance to follow-up visits (OR: 0.33, 0.63, and 0.61 for ≥1997, 1995-1996, and 1988-1994 vs. <1988). CONCLUSION: Patients in the IDU category, patients without AIDS diagnosis, or patients with higher CD4 counts are more likely to miss medical appointments and discontinue their follow-up. More recently enrolled patients have a lower risk of failing to return. It is possible that the recent and more effective anti-HIV treatment played a major role in increasing adherence to follow-up.

African Sleeping Sickness in Tourists Returning from Tanzania: The First 2 Italian Cases from a Small Outbreak among European Travelers

A recent cluster of cases of African trypanosomiasis in humans (HAT) has been reported in tourists (most of whom were European) returning from Tanzania; we describe the first 2 patients (both of whom were Italian travelers) with HAT, who have been treated successfully. Because neither vaccine nor drug prophylaxis is currently recommended and/or available for persons traveling to areas of endemicity, physicians should be alerted about this uncommon but potentially life-threatening disease.

Outcome of 2 Simplification Strategies for the Treatment of Human Immunodeficiency Virus Type 1 Infection

In a prospective, open-label, 104-week study, patients who were infected with human immunodeficiency virus type 1 (virus load, <50 copies/mL) and who were receiving protease inhibitor-based therapy were randomly assigned to continue treatment with a protease inhibitor or to replace it with abacavir or efavirenz. Treatment failure, defined as virological failure (virus load, >500 copies/microL) or any clinical or biochemical adverse event with a grade of >or=3 (on the basis of the World Health Organization [WHO] or American Heart Association [AHA] scales), was the primary outcome measurement. Failure rates were more frequent in the group treated with protease inhibitors (P<.01), and there were no significant differences in the rate of treatment failure between the group treated with efavirenz and the group treated with abacavir. Tolerability was better in the groups treated with abacavir or with efavirenz versus those treated with protease inhibitors. Fewer patients who received efavirenz experienced viral rebound. Among all groups, the mean increase in the CD4 cell count was 131 cells/microL (P<.001), with no significant difference between groups. This switching strategy maintains optimal levels of virological suppression and may improve lipid profiles in most patients.

CD4 cell-guided scheduled treatment interruptions in HIV-infected patients with sustained immunologic response to HAART.

OBJECTIVE To compare continuous HAART with a CD4 cell-driven scheduled treatment interruption (STI) strategy. METHODS LOng Term Treatment Interruption study is a randomized, controlled, prospective trial. Patients with CD4 cell counts more than 700 cells/microl were eligible, and the immunologic threshold to resume HAART was 350 cells/microl. The primary end point was the development of an opportunistic disease, death from any cause or the occurrence of diseases, other than opportunistic, requiring hospital admission. Secondary end points were major adverse effects, virologic failures and therapeutic costs. RESULTS Three hundred and twenty-nine patients were randomized 1: 1. Total follow-up was 1388 person-years (mean 4.2 years). Patients in the STI group stopped therapy for a total of 241 STI cycles, their mean off-therapy period was 65.3% of the follow-up. The primary end point occurred in 12.1% of patients on STI and in 11.6% of controls [odds ratio 1.05; 95% confidence interval 0.54-2.05]. A higher proportion of patients in the STI arm were diagnosed with pneumonia (P = 0.037), whereas clinical events influencing the cardiovascular risk of patients were significantly (P < 0.0001) more frequent among controls. Eight patients (4.8%) in the STI group and 11 (6.7%) controls developed viral resistance [odds ratio 0.79, 95% confidence interval 0.27-1.81]. The mean daily therapeutic cost was 20.29 euro for controls and dropped to 9.07 euro in the STI arm (P < 0.0001). CONCLUSION The two strategies may be considered clinically equivalent. CD4 cell-guided STIs seem a possible alternative for chronically infected individuals responding to HAART provided that CD4 cell decrements would be steadily maintained above a safe threshold.

Exposure-related effects of atazanavir on the pharmacokinetics of raltegravir in HIV-1-infected patients.

Raltegravir (RAL) is primarily metabolized by uridine diphosphate-glucorunosyl transferase 1A1 (UGT1A1). Atazanavir (ATV), a strong inhibitor of UGT1A1, has been shown to increase plasma concentrations of RAL by approximately 50% in healthy volunteers. However, the extent of this interaction has not been studied in HIV-infected patients. A pharmacokinetic study was performed in 22 HIV-infected adults treated with 400 mg RAL plus 300 mg ATV 300 twice a day. Both drugs showed high pharmacokinetic variability (RAL AUC0-12 7649 ± 4862 ng*h/mL; ATV AUC0-12 = 19237 ± 13136 ng*h/mL). Notably, RAL trough concentrations were significantly higher compared with those measured in HIV subjects (n = 24) on RAL plus nucleoside reverse transcriptase inhibitors (506 ± 411 versus 177 ± 262 ng/mL, P < 0.01). A significant correlation was found between RAL and ATV area under the curve (AUC) (r = 0.611, P = 0.005). Notably, patients with ATV AUC0-12 above the mean or with concentrations exceeding the half maximal inhibitory concentration for UGT1A1 had twofold higher RAL AUCs compared with patients with lower ATV exposure. Coadministration of ATV significantly increased plasma concentrations of RAL, especially in HIV-1-infected patients exposed to high concentrations of the protease inhibitor. This pharmacokinetic drug interaction could be handled by routine measurements of ATV trough concentrations and by the assessment of plasma RAL concentrations 2 to 3 hours after the morning drug intake.

Severe lactic acidosis and thiamine administration in an HIV-infected patient on HAART

Severe lactic acidosis has been increasingly reported as a potentially fatal complication of HIV treatment. We report on an asymptomatic HIV-infected woman treated with stavudine, lamivudine and indinavir for one year. She was hospitalized because of progressive dispnoea, oedema, cyanosis and severe lactic acidosis. Arterial blood pH was 6.98, bicarbonate 4.4 mmol/l (normal value 22-26), blood lactate: 29.7 mmol/l (normal value <2.2). Hepatic function was normal. She had an impressively rapid response (within a few hours) to empirical treatment with thiamine (100 mg i.v.). No evidence of sepsis or malabsorption were identified and vitamin B1 level was not tested before thiamine infusion. Three months later she was re-started successfully on nelfinavir plus nevirapine. The rapid response to thiamine infusion deserves a careful attention and such an approach should be considered in similar cases as a support treatment of this potentially life-threatening complication of HIV therapy.