Markers of response to zidovudine monotherapy among treated HIV seroconverters. Italian Seroconversion Study

The aim of the study was to evaluate indicators of response to zidovudine monotherapy in terms of progression to AIDS and death in a cohort of human immunodeficiency virus (HIV) seroconverters. From a larger observational epidemiological cohort of 1,024 HIV seroconverters we identified 315 persons on zidovudine monotherapy. In this treated cohort, age, sex, risk group, constitutional symptoms, CD4 cell count, and p24 antigen levels at initiation of treatment and 6 months later were examined separately for two outcomes, AIDS and death, using standard survival methods. The variables measured at the visit at which zidovudine monotherapy was initiated that predicted more rapid progression to AIDS were CD4 cell count (RH = 2.61); constitutional symptoms (RH = 2.56); p24 antigenaemia level (RH = 2. 17); and subsequent change in CD4 cell count (> 30% decline) contributed additional predictive information (RH = 2.70). Results were similar for mortality, and did not vary significantly by risk group. In a tested subset of patients, p24 antigenaemia was associated with high levels of plasma RNA viral load. The median number of HIV RNA copies was about 28,000 copies/ml among p24 antigen-positive individuals and about 7,700 copies/ml among participants who were persistently negative for p24 antigenaemia. CD4 cell count, symptoms and p24 antigenaemia at the start of therapy and CD4 cell decline after initiation of treatment are early indicators of disease progression in zidovudine-treated patients. The combined use of these indicators may help to better predict who will respond to zidovudine or to other antiretroviral therapies.     

Pharmacokinetic evaluations of low- and high-dose zidovudine plus high-dose acyclovir in patients with symptomatic human immunodeficiency virus infection.

The pharmacokinetics of zidovudine were evaluated in 41 patients with Centers for Disease Control HIV class IVA infection. The patients were assigned escalating doses of zidovudine (300, 600, or 1,500 mg daily) and were randomized to receive either zidovudine alone or zidovudine with a high dose of acyclovir (4,800 mg per day). Single and multiple intravenous- and oral-dose pharmacokinetic studies were performed on days 1 and 7 and weeks 6 and 12 of therapy. Zidovudine concentrations were analyzed by high-pressure liquid chromatography. Pharmacokinetic parameters were estimated by noncompartmental methods. Zidovudine concentrations in serum declined in a biphasic manner, with half-lives ranging from 1 to 2 h, and were independent of acyclovir administration or length of zidovudine therapy. The median time of peak concentrations in serum following oral doses was 0.75 h (range, 0.25 to 3 h). Accumulation of zidovudine in serum was not observed, but the maximum concentration of drug in serum (Cmax) and the area under the concentration-time curve increased proportionally with increased zidovudine doses. Mean day 7 oral Cmax values were 0.20 +/- 0.12, 0.55 +/- 0.33, and 1.0 +/- 0.5 micrograms/ml for 17 patients receiving total daily doses of, respectively, 300, 600, and 1,500 mg of zidovudine alone, whereas Cmax values were, respectively, 0.27 +/- 0.18, 0.43 +/- 0.33, and 1.2 +/- 0.80 micrograms/ml for 15 comparably treated recipients of zidovudine plus acyclovir (P was not significant). The median bioavailability of oral zidovudine was 67% (42 to 120%) and did not vary with dosage. Absolute and apparent total body clearances were similar among the patients given the various zidovudine doses regardless of whether there was concomitant acyclovir therapy. Drug-related toxicities were observed more frequently in the subjects who received high doses of zidovudine than they were in those who received median and low doses of zidovudine (P=0.03). Overall, acyclovir did not influence the disposition of zidovudine over a wide range of zidovudine doses. No unusual toxicities could be attributed to the zidovudine and high-dose acyclovir combination during the 12-week observation period.     

Demographics of HIV survival revisited

HIV mortality among blacks, women, and injection drug users is disproportionately high in comparison to other HIV-infected populations. It has been noted that differential survival may be related to access to care. A team at Johns Hopkins followed 1,372 patients at a single urban HIV clinic over 1.6 years. During this time, 427 patients died. After adjusting for CD4 counts, there was not a significant difference in survival between men and women, blacks and whites, injection drug users and non-users, and people with annual incomes above and below $5,000. Predictors of mortality included initial CD4 counts below 350 cells/mm3, prior antiretroviral therapy, and older age; and indicators of survival included employment at enrollment, antiretroviral therapy after enrollment, and PCP prophylaxis. These findings indicate that access to care needs to be improved, since demographic differences in survival disappear when care and other factors are held constant.     

Effect of dipyridamole on zidovudine pharmacokinetics and short-term tolerance in asymptomatic human immunodeficiency virus-infected subjects.

Zidovudine delays the progression of infection and prolongs the survival of human immunodeficiency virus (HIV)-infected patients, but these benefits are limited by dose-related toxicity and the cost of the drug. Dipyridamole, in micromolar concentrations, acts synergistically with zidovudine, reducing the anti-HIV 95% inhibitory concentration of zidovudine 5- to 10-fold in vitro. We sought to establish a well-tolerated dose of dipyridamole for use in combination with zidovudine and to detect clinically significant pharmacokinetic interactions. Both objectives are essential for planning studies of the efficacy of the zidovudine-dipyridamole combination. Eleven asymptomatic HIV-infected subjects (median CD4+ cell count, 311 cells per mm3), 10 of whom had been on zidovudine at 500 mg/day for at least 6 months, were admitted to the study. Zidovudine pharmacokinetics were measured on day 1. Dipyridamole was then begun at 600 mg/day (subjects 1 to 3) or 450 mg/day (subjects 4 to 11), and zidovudine and dipyridamole pharmacokinetics were measured on day 5. All subjects given 600 mg of dipyridamole per day developed headache or nausea, or both. Six of eight subjects given dipyridamole at 450 mg/day developed headache or mild nausea that resolved after a median of 2 days. The area under the zidovudine concentration-time curve was not significantly different on day 1 in comparison with that on day 5 (P = 0.11). Symptoms were significantly correlated with the maximum zidovudine concentrations, which were achieved when dipyridamole was dosed concomitantly (p = 0.03). Total (free and protein-bound) dipyridamole trough concentrations were near those demonstrating synergy with zidovudine against HIV in vitro. Dipyridamole was highly protein bound, with a median free/total dipyridamole ratio of 0.7%; the percent free/total dipyridamole ratio was inversely correlated with alpha 1 acid glycoprotein concentrations (r2 =0.66). Results of the study indicate that adjustment of the zidovudine dose was not required to achieve equivalent zidovudine concentrations when zidovudine was administered in combination with dipyridamole at the doses studied. In the short study described here, the zidovudine-dipyridamole combinations was well tolerated in asymptomatic HIV-infected subjects after the occurrence of mild transient symptoms.     

Antiretroviral therapy based on protease inhibitors as a protective factor against liver fibrosis progression in patients with chronic hepatitis C

Cohort studies have shown that highly active antiretroviral therapy (HAART) can improve liver-related mortality in HIV/hepatitis C virus (HCV)-coinfected patients. A reduction in the accelerated liver fibrosis progression observed in HIV infection induced by HAART could explain these findings. A few studies have assessed the impact of HAART on liver fibrosis, but with contradictory results. Therefore, we evaluated the associations between the use of different antiretroviral drug classes and HAART combinations, and liver fibrosis in HIV-infected patients with chronic hepatitis C. Six hundred and eighty-three HIV/HCV-coinfected patients, who underwent a liver biopsy and who had not received anti-HCV treatment were included. Age at HCV infection < 23years (adjusted odds ratio [AOR] = 0.7, 95% confidence interval [95% CI] = 0.3-0.9, P = 0.05) and protease inhibitor (PI)-based HAART versus no use of HAART (AOR = 0.5, 95% CI = 0.3-0.9, P = 0.01) were negatively associated with advanced fibrosis (> or = F3). PI-based HAART versus no use of HAART (AOR = 0.4, 95% CI = 0.2-0.7, P = 0.001) was negatively associated with fibrosis progression rate > or = 0.2 units/year and independently of age at HCV infection and CD4+ T-cell counts. Fifteen (17%) patients treated only with PIs and zidovudine plus lamivudine showed > or = F3, compared with 65 (37%) patients without HAART (P = 0.001). Forty (31%) patients on PI and stavudine plus lamivudine showed > or = F3 (P = 0.3, when compared with patients with no HAART). The use of PI-based HAART in HIV/HCV-coinfected patients is associated with less severe fibrosis and slower progression of fibrosis. The nucleoside analogue backbone in a HAART regimen may influence this association.     

Time-dependence of survival predictions based on markers of HIV disease. Swiss HIV Cohort Study.

OBJECTIVE: To determine whether the ability of baseline clinical stage, viremia, and CD4 cell counts to predict mortality in HIV-1-infected patients changes with duration of follow-up. METHODS: Three hundred ninety-four patients were followed for an average of 29 months by the Swiss HIV Cohort Study, a practice-based registry of HIV-1-infected patients in Switzerland. Predictor variables were the baseline clinical stage, CD4 cell count, circulating HIV-1 RNA level, and the RNA/CD4 ratio; the outcome was death. The changes in relative risks of death over time were examined using survival models that extend the Cox model to allow for nonproportionality of hazards. RESULTS: During 949 person-years of follow-up, 169 patients died (mortality rate 17.8 per 100 person-years). Compared with clinical stage A, patients in stages B and C at baseline had much higher mortality rates in the subsequent year. The prognostic ability of stage C decayed over time (P = 0.03). By contrast, the relative risks associated with a 2-fold difference in CD4 counts remained remarkably stable, at approximately 0.6 (P = 0.81 for the time-dependence test). Relative hazards associated with a 10-fold difference in HIV RNA per milliliter and in HIV RNA per CD4 cell both tended to increase over time, but this trend failed to reach statistical significance (P = 0.21 and P = 0.08, respectively). CONCLUSIONS: Time-dependence patterns of prognostic ability varied widely among predictors, displaying gradual decay (clinical stage), stability (CD4 cells), and a trend to progressive increase (viremia). These results may affect clinical monitoring of HIV-infected patients and the interpretation of cohort studies of HIV-infected patients.     

非小细胞肺癌合并人类免疫缺陷病毒阳性患者29例的外科治疗分析

目的评价手术治疗非小细胞肺癌(NSCLC)合并人类免疫缺陷病毒(HIV)阳性患者的临床效果。方法回顾性分析收集1998年9月至2006年4月莫桑比克马普托中心医院胸外科手术治疗的NSCLC合并HIV阳性患者29例(HIV阳性组),并选择同期34例HIV检测呈阴性NSCLC患者作为对照组(HIV阴性组)。分析两组患者的手术时间、术中出血量、术后引流量、手术后胸腔引流量、手术后肺部和伤口感染率、手术后住院日、HIV阳性组CD4计数,并随访生存时间等临床指标。结果两组患者手术在死亡率上的差异没有统计学意义;HIV阳性组手术后肺部感染发生率比HIV阴性组高(31.03%vs5.88%,P=0.009),前者发生手术后肺部感染的危险比后者增加7倍以上(OR=7.200;95%可信区间(1.409,36.779));HIV阳性患者不同CD4计数手术后肺部感染发生率的差异有统计学意义(P=0.040),CD4计数与手术后肺部感染发生率呈负相关(r=-0.501;P=0.014);HIV阳性组与HIV阴性组患者在生存时间上差异无统计学意义(P=0.248)。结论 NSCLC合并HIV阳性患者手术后并发肺部感染危险增加且与患者CD4细胞计数呈负相关,但不会增加手术死亡率;伴随高效抗逆转录病毒治疗(HAART)的实行,其手术后生存期与HIV阴性者相似。对于非艾滋病发作期的该类患者,均应考虑积极地治疗。     

A randomized controlled trial to enhance antiretroviral therapy adherence in patients with a history of alcohol problems

OBJECTIVE: To assess the effectiveness of an individualized multicomponent intervention to promote adherence to antiretroviral therapy (ART) in a cohort of HIV-infected individuals with a history of alcohol problems. DESIGN: We conducted a randomized controlled trial to compare the usual medical follow-up with an adherence intervention. SETTING: The principal enrolment site was Boston Medical Center, a private, not-for-profit, academic medical institution. SUBJECTS: HIV-infected patients with a history of alcohol problems on ART. A total of 151 were enrolled and 141 (93%) were assessed at follow-up. Intervention: A nurse, trained in motivational interviewing, completed the following over 3 months in four encounters: addressed alcohol problems; provided a watch with a programmable timer to facilitate pill taking; enhanced perception of treatment efficacy; and delivered individually tailored assistance to facilitate medication use. MAIN OUTCOME MEASURES: Prior 30-day adherence > or =95%, prior 3-day adherence of 100%, CD4 cell count, HIV RNA and alcohol consumption, each at both short- and long-term follow-up. RESULTS: At follow-up, no significant differences in medication adherence, CD4 cell count, HIV RNA or alcohol consumption were found (all P values >0.25). CONCLUSIONS: A multicomponent intervention to enhance adherence among HIV-infected individuals with a history of alcohol problems was not associated with changes in medication adherence, alcohol consumption or markers of HIV disease progression. The failure to change adherence in a group at high risk for poor adherence, despite utilizing an intensive individual-focused patient intervention, supports the idea of addressing medication adherence with supervised medication delivery or markedly simplified dosing regimens.     

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 < or =500 copies/ml) and immunological success (a CD4+ count increase of > or =200 cells/microl), 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.     

Decreasing CD4+ T-cell count during suppressed or low-level viraemia in patients with HIV infection

BACKGROUND: Suboptimal improvement in CD4+ T-cell count is not uncommon in HIV-infected patients with suppressed plasma HIV RNA levels, and a decrease in CD4+ T-cell count in patients with suppressed or low-level viraemia has been observed. METHODS: Our objectives were to identify the prevalence of decreasing CD4+ T-cell counts during suppressed or low-level viraemia, to determine the frequency of clinical events during and immediately after such decreases, and to examine for associations with individual variables. A matched case-control study was undertaken using the Duke Infectious Diseases Clinic database (n = 3,949). Cases had at least two consecutive significant decreases in either CD4+ absolute count or CD4+ percentage, while also having plasma HIV RNA levels < 1,000 copies/ml. RESULTS: The prevalence of decreasing CD4+ T-cell counts during suppressed or low-level viraemia was 1.22%. Only three HIV-associated clinical events occurred. The majority of cases had an increase in the CD4+ T-cell count immediately following the study period. The use of either zidovudine or stavudine was weakly associated with decreasing CD4+ T-cell counts in a multivariable analysis, but this association was not present in cases with only a decrease in CD4+ T-cell percentage. CONCLUSIONS: Decreasing CD4+ T-cell counts during suppressed or low-level viraemia are rare, typically transient, and not associated with an increase in HIV-associated clinical events.     

中国HIV早期感染者CD+4CD+25Foxp3+调节性T淋巴细胞变化研究

目的 研究1年以内感染HIV的感染者(早期感染者,EHI)体内CD+4 CD+25 Foxp3+调节性T淋巴细胞水平及其与疾病进展相关性.方法 随机选取51例HIV感染者,依据感染时间及CD+4 T淋巴细胞水平分为3组:EHI组30例、HIV组15例、AIDS组6例,20名健康人作为对照组,各组对象的年龄、性别具有可比性.用EDTA抗凝管采集全血,应用FACSAria流式细胞仪及Foxp3染色试剂盒,检测外周血单个核细胞CD+4CD+25Foxp3+调节性T淋巴细胞表达水平,分析EHI者及全部HIV感染者CD+4 CD+25Foxp3+调节性T淋巴细胞表达水平与CD+4T淋巴细胞数量、病毒调定点、病毒载量及淋巴细胞活化水平间的相关性.结果 健康对照组、EHI组、HIV组及AIDS组CD+4C+25Foxp3+T淋巴细胞百分率逐级上升,其中EHI组CD+4CD+25Foxp3+T淋巴细胞百分率[3.79(2.11～5.43)%]低于AIDS组[8.09(4.90～8.90)%],差异有统计学意义(Z=-2.29,P=0.022);EHI组CD+4 CD+25Foxp3+T淋巴细胞百分率与病毒调定点正相关(r=0.479,P=0.038),与CD4T淋巴细胞计数呈负相关(r=-0.455,P=0.011),与CD+3 HLA+T淋巴细胞呈正相关(r=0.533,P=0.002).结论 中国EHI者CD+4 CD+25Foxp3+调节性T淋巴细胞百分率高与高病毒调定点及低CD+4 T淋巴细胞数量相关,提示CD+4 CD+25Fox3+调节性T淋巴细胞是加速HIV感染早期疾病进展的因素之一.     

Zidovudine, trimethoprim, and dapsone pharmacokinetic interactions in patients with human immunodeficiency virus infection.

Zidovudine is widely prescribed for the treatment of human immunodeficiency virus (HIV) infection. Trimethoprim and dapsone are commonly used in the management of Pneumocystis carinii pneumonia in HIV-infected patients. To examine the pharmacokinetic interactions among these drugs, eight HIV-infected patients (26 to 43 years old) with a mean CD4 count of 524.4 +/- 405.7 cells per mm3 received zidovudine (200 mg), trimethoprim (200 mg), and dapsone (100 mg) as single agents and in two- and three-drug combinations. Blood and urine samples were collected at a specified time and analyzed for zidovudine, zidovudine-glucuronide, trimethoprim, dapsone, and monoacetyl-dapsone concentrations under single-dose and steady-state conditions. Zidovudine did not influence the pharmacokinetic disposition of dapsone or trimethoprim. Dapsone had no effect on the pharmacokinetic disposition of zidovudine. Trimethoprim significantly decreased the renal clearance of zidovudine by 58% (5.0 +/- 1.8 versus 2.1 +/- 0.5 ml/min/kg of body weight [P < 0.05]). There was a concurrent 54% decrease in the mean urinary recovery of zidovudine (11.7 +/- 3.5 versus 5.4 +/- 3.0 [P < 0.05]), and the metabolic ratio was decreased by 78% (0.32 +/- 0.4 versus 0.07 +/- 0.05 [P < 0.05]). The mean area under the concentration-time curve from 0 to 6 h of the zidovudine-glucuronide/ zidovudine ratio was unchanged. We conclude that zidovudine, trimethoprim, and dapsone can be coadministered to patients with AIDS without significant pharmacokinetic interaction. However, in AIDS patients with liver impairment and impaired glucuronidation, doses of zidovudine may need to be decreased.     

Risks of non-accidental mortality by baseline CD4+ T-cell strata in hepatitis-C-positive and -negative individuals initiating highly active antiretroviral therapy

BACKGROUND: Patients coinfected with hepatitis C virus (HCV) and HIV experience higher mortality rates than patients infected with HIV alone. We designed a study to determine whether risks for later mortality are similar for HCV-positive and HCV-negative individuals when subjects are stratified on the basis of baseline CD4+ T-cell counts. METHODS: Antiretroviral-naive individuals, who initiated highly active antiretroviral therapy (HAART) between 1996 and 2002 were included in the study. HCV-positive and HCV-negative individuals were stratified separately by baseline CD4+ T-cell counts of 50 cell/microl increments. Cox-proportional hazards regression was used to model the effect of these strata with other variables on survival. RESULTS: CD4+ T-cell strata below 200 cells/microl, but not above, imparted an increased relative hazard (RH) of mortality for both HCV-positive and HCV-negative individuals. Among HCV-positive individuals, after adjustment for baseline age, HIV RNA levels, history of injection drug use and adherence to therapy, only CD4+ T-cell strata of <50 cells/microl (RH=4.60; 95% confidence interval [CI] 2.72-7.76) and 50-199 cells/microl (RH=2.49; 95% CI 1.63-3.81) were significantly associated with increased mortality when compared with those initiating therapy at cell counts >500 cells/microl. The same baseline CD4+ T-cell strata were found for HCV-negative individuals. CONCLUSION: In a within-groups analysis, the baseline CD4+ T-cell strata that are associated with increased RHs for mortality are the same for HCV-positive and HCV-negative individuals initiating HAART. However, a between-groups analysis reveals a higher absolute mortality risk for HCV-positive individuals.     

Meta-analysis of five randomized controlled trials comparing continuation of zidovudine versus switching to didanosine in HIV-infected individuals

A meta-analysis of the original data from 2411 patients in the ACTG 116A, ACTG116B/117, ACTG175, BMS010 and CTN002 trials was conducted to improve the estimate of the effect of switching from zidovudine to didanosine on rates of clinical progression, to better quantify the rates of neurological events (including AIDS dementia and peripheral neuropathy) and to examine the effects of switching from zidovudine to didanosine among women and racial subgroups. In total, 1012 patients received zidovudine therapy, 557 received high-dose didanosine and 842 received didanosine. The median duration of follow-up was 15 months. Ninety-one percent of patients were male, 78% were white, mean age was 36.5 years. The median CD4 count was 195 cells/mm3 (range: 0-762) and the median duration of prior zidovudine therapy was 14 months (range: 0.1-94). There were 336 deaths and 686 new AIDS-defining illnesses (ADIs) or deaths. After stratification by study and adjusting for baseline CD4 count and presence of an AIDS diagnosis prior to baseline, the relative risks of death associated with switching from zidovudine to high-dose didanosine or to didanosine were 0.94 (P = 0.64) and 0.77 (P = 0.07), respectively. The relative risks of a new ADI or death associated with switching from zidovudine to high-dose didanosine and didanosine were 0.78 (P = 0.01) and 0.66 (P = 0.0001), respectively. There were 21 documented cases of AIDS dementia complex (ADC) during the entire follow-up period. The rates per 100 person years of follow-up were 0.70, 0.65 and 0.41 for the zidovudine, high-dose didanosine and didanosine arms, respectively. There were no significant differences in risks of ADC between treatment arms (zidovudine versus high-dose didanosine: P = 0.30, zidovudine versus didanosine: P = 0.97, didanosine versus high-dose didanosine: P = 0.41). Our data confirm a clinical benefit and CD4 increase associated with a switch from zidovudine to didanosine therapy. No statistical differences were detected between doses of didanosine with respect to survival or progression to a new ADI or death. Furthermore, there was no statistical difference in the frequency of ADC between treatment arms.     

Histoplasmosis in HIV-infected patients in a southern regional medical center: poor prognosis in the era of highly active antiretroviral therapy

Histoplasmosis is an important opportunistic infection among HIV-infected patients in endemic areas, and clinical outcomes are often poor. Additional data on factors associated with outcomes are needed to better identify patients who may require aggressive care. Using a cohort of 46 HIV-infected patients with histoplasmosis from an underserved city endemic for histoplasmosis, we explored epidemiology, outcomes, and prognostic factors. Histoplasmosis was the 1st recognized manifestation of HIV infection in 12 (26.1%) of 46 patients. Death occurred in 18 (39%) patients within 3 months of diagnosis of histoplasmosis. Fungemia (odds ratio [OR], 12.1; 95% confidence interval [CI], 1.9-76; P=0.008), renal insufficiency (OR, 11.3; 95% CI, 1.7-77.2; P=0.01), and age (OR, 0.9; 95% CI, 0.8-0.98; P=0.02) were independent predictors of poor prognosis. Histoplasmosis in HIV patients is associated with poor outcomes. Identification of prognostic factors may be helpful in identifying patients who require more aggressive care.     

HAART tolerability: post-exposure prophylaxis in healthcare workers versus treatment in HIV-infected patients

The aim of our study is to compare the tolerability of zidovudine/lamivudine/indinavir when used in post-exposure prophylaxis (PEP) subjects and in HIV-infected patients. HIV-negative patients were enrolled as part of the surveillance protocol for professional exposure at the Luigi Sacco Hospital in Milan. HIV-positive patients were selected among all subjects undergoing treatment with zidovudine/lamivudine/indinavir from the CISAI cohort, an Italian cohort for the evaluation of adverse reactions to HAART. In both studies patients were followed prospectively and the severity of the reactions was evaluated using the AIDS Clinical Trial Group adverse experience grading scales. Up to September 1999, 37 HIV-seronegative subjects had undergone treatment with zidovudine/ lamivudine/indinavir. From a total of 1207 patients belonging to the CISAI cohort, 199 were identified as being treated with the same regimen. The frequency of adverse events in the PEP subjects was 70.3% compared to 11.1% for HIV-infected patients. In the first group, adverse events caused treatment interruption in 21 subjects (56.7%) versus 14 patients (7%) among the HIV-infected group. Only one case of a severe event (grade 3-4) was observed in the prophylaxis group against 12 in the treatment group. Our study shows that treatment interruption is eight times higher in HIV-negative subjects compared to HIV-seropositive patients, and that the incidence of adverse events is approximately six times higher, though such events, are for the most part, not severe.     

A randomized controlled trial of a protease inhibitor (saquinavir) in combination with zidovudine in previously untreated patients with advanced HIV infection

This study assessed the activity and tolerability of an HIV-protease inhibitor, saquinavir, alone or in combination with zidovudine. A total of 92 previously untreated HIV-infected patients with CD4 cell counts < 300 cells/mm3 participated in a parallel, randomized double-blind study. Patients were randomized to receive one of five treatments, each three times a day: 600 mg of saquinavir; 200 mg of zidovudine; 75, 200 or 600 mg of saquinavir in combination with 200 mg of zidovudine. The primary treatment period was 16 weeks, with monthly extensions in patients who did not show major disease progression or toxicity. The main measures of the efficacy of therapy used were changes in CD4 cell counts and in the concentration of HIV-1 RNA in the plasma (as determined by quantitative polymerase chain reaction). The 600 mg dose of saquinavir in combination with zidovudine induced a 1.6 log (after 4 weeks) and a 0.7 log (after 16 weeks) median reduction in plasma RNA concentration; this reduction was greater than those seen in the other four treatment groups. The combination of 600 mg of saquinavir with zidovudine also resulted in a larger and more sustained improvement in the CD4 cell count than either saquinavir or zidovudine monotherapy or the other combination therapies. In the group receiving 200 mg of saquinavir in combination with zidovudine, the maximal median change in CD4 cell count occurred at week 2 (85 cells/mm3), and by week 16 had fallen to 15 cells/mm3. In the group receiving 600 mg of saquinavir plus zidovudine, the median change in CD4 cell count remained high for the 16-week period (median change of 48 cells/mm3 at week 2 and 61 cells/mm3 at week 16). Saquinavir was safe and very well tolerated, either alone or in combination with zidovudine. The incidence of adverse events was greater in the four groups receiving zidovudine therapy, and all the most commonly reported adverse events have previously been associated with zidovudine therapy. Few changes in laboratory values occurred during the study, except for known zidovudine-associated toxicities. The most frequent abnormalities were raised aspartate aminotransferase and alanine aminotransferase levels, depressed calcium levels, and abnormally high or low phosphate levels. Despite the low oral bioavailability of saquinavir, combined virological and immunological data show definite antiviral activity in vivo for the combination of saquinavir at 600 mg plus zidovudine at 200 mg (each three times daily). The combination of drugs with different mechanisms of action represents an advance in the treatment of HIV infection.