Dante Bassetti

Mother to child transmission of HIV infection in the era of highly active antiretroviral therapy

BACKGROUND Very low rates of mother-to-child transmission (MTCT) of human immunodeficiency virus (HIV) are achievable with use of highly active antiretroviral therapy (HAART). We examine risk factors for MTCT in the HAART era and describe infants who were vertically infected, despite exposure to prophylactic MTCT interventions. METHODS Of the 4525 mother-child pairs in this prospective cohort study, 1983 were enrolled during the period of January 1997 through May 2004. Factors examined included use of antiretroviral therapy during pregnancy, maternal CD4 cell count and HIV RNA level, mode of delivery, and gestational age in logistic regression analysis. RESULTS Receipt of antenatal antiretroviral therapy increased from 5% at the start of the HAART era to 92% in 2001-2003. The overall MTCT rate in this period was 2.87% (95% confidence interval [CI], 2.11%-3.81%), but it was 0.99% (95% CI, 0.32%-2.30%) during 2001-2003. In logistic regression analysis that included 885 mother-child pairs, MTCT risk was associated with high maternal viral load (adjusted odds ratio [AOR], 12.1; P=.003) and elective Caesarean section (AOR, 0.33; P=.04). Detection of maternal HIV RNA was significantly associated with antenatal use of antiretroviral therapy, CD4 cell count, and mode of delivery. Among 560 women with undetectable HIV RNA levels, elective Caesarean section was associated with a 90% reduction in MTCT risk (odds ratio, 0.10; 95% CI, 0.03-0.33), compared with vaginal delivery or emergency Caesarean section. CONCLUSIONS Our results suggest that offering an elective Caesarean section delivery to all HIV-infected women, even in areas where HAART is available, is appropriate clinical management, especially for persons with detectable viral loads. Our results also suggest that previously identified risk factors remain important.

Nosocomial epidemic of active tuberculosis among HIV-infected patients.

In an investigation of a nosocomial outbreak of tuberculosis, 18 HIV-infected inpatients were found to have been exposed to Mycobacterium tuberculosis; active tuberculosis developed in 8, 7 within 60 days of diagnosis of the index case. The patients with lower total lymphocyte and CD4 lymphocyte counts were more likely to get the disease than were those with higher counts. A low score on multiple antigen skin testing was also associated with the development of active tuberculosis. 4 of the 18 patients had a positive tuberculin skin test before exposure to M tuberculosis; none of them subsequently got the disease.

Identification of hepatitis A virus as a trigger for autoimmune chronic hepatitis type 1 in susceptible individuals

To identify factors contributing to the pathogenesis of autoimmune chronic active hepatitis (CAH) healthy relatives of 13 patients with the disorder were followed prospectively for 4 years. 58 relatives were monitored for various serological markers and for T-lymphocyte migration inhibitory activity every 2 months. 3 cases of subclinical acute hepatitis A occurred during the study. In 2 of the 3 subjects, before hepatitis A virus (HAV) infection, there was a defect in suppressor-inducer T lymphocytes specifically controlling immune responses to the asialoglycoprotein receptor, an antigen expressed on the hepatocyte surface. In these 2 subjects, specific helper T cells and antibodies to the asialoglycoprotein receptor persisted and increased after acute hepatitis A, and autoimmune CAH type 1 developed within 5 months. Thus, in susceptible individuals HAV is a trigger for autoimmune CAH.

The relationship between ritonavir plasma levels and side-effects: implications for therapeutic drug monitoring

OBJECTIVES To assess whether the neurological or gastrointestinal adverse effects of ritonavir correlate with parameters of ritonavir systemic exposure. METHODS Peak (Cmax) and trough (Cmin) ritonavir plasma levels were compared in 11 patients experiencing side-effects (group A) versus 10 patients without side-effects (group B). Ritonavir was administered with the following escalation dosing scheme: 300, 400, 500 mg twice a day for 3, 4, and 5 days, respectively, then the full dose of 600 mg twice a day. Blood sampling was done in group A within 24 h of the occurrence of side-effects and in group B after at least 3 days of the full dosage regimen. RESULTS Both Cmax and Cmax were significantly higher (Mann-Whitney U test) in patients with side-effects. Cmax was [median (interquartile range)] 26.7 (22.7-33.3) mg/l versus 16.2 (13.4-17.0) mg/l (P = 0.001) and Cmin was 12.6 (9.1-13.9) versus 7.5 (4.9-8.6) mg/l (P = 0.002). CONCLUSION Patients with higher ritonavir concentrations are at a higher risk of experiencing neurological or gastrointestinal side-effects. Individualization of the dosage regimen, e.g. a downward titration of the ritonavir dose in patients with side-effects, guided by plasma level monitoring, may result in a substantial increase in the percentage of patients tolerating ritonavir without increasing the risk of treatment failure as a result of suboptimal systemic exposure.

Puberty in perinatal HIV-1 infection: a multicentre longitudinal study of 212 children

Objective To define age at entry into Tanner stages in children with perinatal HIV-1 infection. Design Multicentre longitudinal study including 212 perinatally HIV-1-infected children (107 girls and 105 boys) followed-up during puberty (from 8 and 9 years onwards in girls and boys, respectively). Healthy children (843 girls and 821 boys) provided reference percentiles. P2 or B2 stages in girls and P2 or G2 stages in boys defined onset of puberty. Methods The cumulative probability [95% confidence limit (CI)] of entry into each stage at different ages was estimated by the Kaplan–Meier product-limit method; differences were evaluated by log rank test. Relationships were tested using the Spearmans rank correlation coefficient. Results Ages of girls [years (95%CI)] at P2 [12.9 (12.6–13.2)], P3 [13.4 (13.0–13.8)], P4 [14.6 (14.0–15.2)], B2 [12.7 (12.2–13.2)], B3 [13.3 (12.8–14.0)] and B4 [14.6 (14.0–15.2)] stages were > 97th percentile (⩾ 21 month delay) of controls. Ages of boys [years (95%CI)] at P2 [12.6 (12.1–13.1)], P3 [13.9 (13.4–14.4)], P4 [14.9 (14.2–15.6)], G2 [12.1 (11.5–12.7)], G3 [13.6 (13.1–14.1)] and G4 [14.9 (14.1–15.7)] stages were at the 75–97th percentiles (⩽ 15 month delay). Age at onset of puberty was not related to clinical and immunological condition, antiretroviral treatment, weigh for height and age at onset of severe disease or immune suppression. Conclusion Perinatal HIV-1 infection interferes with sexual maturation. The mechanisms by which this occurs should be elucidated and intervention strategies designed. Intervention could save much psychological distress, since associated linear growthfailure can exacerbate adolescents’ feelings of being different and unwell.

In vitro activity of a Combretum micranthum extract against herpes simplex virus types 1 and 2

The authors demonstrate in vitro antiviral activity of a methanolic extract of Combretum micranthum leaves against HSV-1 and HSV-2. This activity is present only in the extract dissolved 7 days before the assay, but not in the freshly prepared extract, thus indicating the presence of inactive precursors which undergo spontaneous transformations into active compounds. The alkaline autooxidation of the methanolic extract promotes this rapid transformation. The precursors have been identified as condensed catechinic tannins, which, under alkaline conditions, suffer rapid cleavage, intramolecular rearrangement to catechinic acid and autooxidation. The alkaline autooxidation products of the methanolic extract of C. micranthum and those of the synthetic catechinic acid show similar I.R. and U.V. absorption curves, as well as similar anti-HSV-1 and -HSV-2 activities. EC50s of catechinic acid autooxidation products against HSV-1 and HSV-2 replication were 2 micrograms/ml and 4 micrograms/ml, respectively, when cell cultures were treated with the compound during virus infection.

Transmission of HIV-Associated Tuberculosis to Healthcare Workers

OBJECTIVE A retrospective investigation was made to compare the occupational risk of tuberculosis in personnel assisting human immunodeficiency virus (HIV)-infected and uninfected subjects with active tuberculosis. DESIGN We retrospectively reviewed 6 years of hospital activity in 3 units where HIV-infected patients with tuberculosis are hospitalized and in 2 units where non-HIV-infected tuberculosis patients are hospitalized. The risk of occupational tuberculosis in healthcare workers who assisted HIV-infected and non-HIV-infected patients with tuberculosis was investigated. PARTICIPANTS The risk of occupational tuberculosis in healthcare workers was studied by considering the numbers of potential source cases (hospitalized patients with tuberculosis) in the two conditions investigated (HIV-positive and HIV-negative). Both potential source cases and cases of tuberculosis in healthcare workers had to be microbiologically proven in order to be considered. RESULTS Seven cases of tuberculosis occurred in persons who cared for 85 HIV-infected subjects with tuberculosis, while only 2 cases occurred in staff members who took care of 1,079 HIV-negative tuberculosis patients over the same period (relative risk = 44.4; 95% confidence interval = 8.5-438). CONCLUSIONS Tuberculosis seems no longer to be a neglectable risk in healthcare workers assisting patients with HIV infection. Further study is urgently needed to see whether such unexpectedly high dissemination of tuberculosis also is demonstrable in the community.

Indinavir Pharmacokinetics and Parmacodynamics in Children with Human Immunodeficiency Virus Infection

ABSTRACT The indinavir dosage regimen currently used for human immunodeficiency virus (HIV)-infected children is not based on pharmacokinetic data obtained in the target patient population. The purpose of our study was to characterize indinavir pharmacokinetics and pharmacodynamics in HIV-infected children. Eleven children (age range, 9.0 to 13.6 years; weight range, 21.7 to 56.0 kg) receiving indinavir (500 mg/m2 every 8 h) in combination with lamivudine and stavudine were studied. The correlation of indinavir pharmacokinetic parameters and demographic parameters was evaluated. Also, the pharmacodynamic relationship between parameters of indinavir exposure and parameters of renal toxicity and immunologic recovery was studied. The area under the indinavir concentration-time curve (AUC) and patient body surface area (BSA) showed a significant negative correlation (r = 0.73; P = 0.012). Patients with smaller BSA had excessive indinavir AUC compared to adults. On the other hand, the median minimum drug concentration in plasma (Cmin) was lower than that reported for adults. The maximum indinavir concentration in serum was higher in patients with renal toxicity (5 out of 11 children), but the difference was not statistically significant (15.3 ± 8.2 versus 9.8 ± 4.4 mg/liter; P = 0.19). There was a trend toward higher immunologic efficacy in patients with greater indinavir exposure: the time-averaged AUC of the percentage of CD4+ lymphocytes over the baseline value for patients with indinavir Cmin > 95% inhibitory concentration (IC95) was higher than in patients withCmin < IC95(P = 0.068). Our study suggests that a dose reduction may be appropriate for children with small BSA and that a 6-h dosage regimen may be indicated for a substantial percentage of patients. Due to the low number of patients enrolled in this study, our results should be confirmed by a larger study.

Adherence to combination antiretroviral treatment in children.

Abstract Purpose: To assess the level of nonadherence to combination antiretroviral therapy of HIV-infected children and to identify the main problems faced by caregivers when giving medicines to children. Method: A questionnaire was administered to the caregivers of HIV-infected children who were under combination antiretroviral treatment and were followed at our institution. Results: We evaluated 44 children (mean age, 9.4 years); 13 were treated with a two-drug regimen, 30 with a three-drug regimen, and 1 with a four-drug regimen. Each child received a mean of 8.1 pills and/or syrup doses. In 54.5% of treatments, food restrictions were necessary. The mother was the main person giving medicines to the child (56.8%). A complete written schedule of the child’s treatment was present in 50% of families. About 20.5% and 31.8% of children had missed at least one dose of antiretroviral drugs in the last 3 days before assessment and since last visit (1-2 months earlier), respectively. Main problems reported by caregivers were: (a) too many medicines/ pills (34%); (b) difficulty in swallowing pills (29.5%); (c) taking medicines at school or out of home (27.3%); (d) child resisting/refusing therapy/spitting out (25%); and (e) food interactions (22.7%). Conclusion: The observed high level of nonadherence was similar to what was reported by other pediatric studies. Specific interventions aimed at improving compliance in pediatric patients were identified: improvement of anti-HIV drug formulations, better counselling for children and their families, and tailoring of antiretroviral treatment. However, caution is necessary in generalizing our results due to the small sample size and to the heterogeneity of the cohort.

Impact of an antimicrobial formulary and restriction policy in the largest hospital in italy

We have analysed the expenditure on antimicrobial drugs in the largest hospital in Italy; over this period, a committee prepared an antibiotic policy document. This formulary lists all antimicrobial drugs available in the hospital. Some drugs were removed from the list and others are only available on special request for a named patient. In the hope of optimising drug utilisation, we included all the reasons for the choice of agent in the document. The introduction of this formulary resulted in an immediate saving and perhaps in the future we shall also observe an improvement in bacterial resistance patterns.