Performance evaluation of a self-administered point-of-care test for anal HPV screening in PrEP users: data from a community-based PrEP service.

OBJECTIVES: In this study, we compared the performance of a self-administered point-of-care test (POCT) for anal human papillomavirus (HPV) screening with laboratory gold-standard test in pre-exposure prophylaxis (PrEP) users and evaluated its feasibility. METHODS: We enrolled PrEP users from a local community-based PrEP service. Each participant self-collected an anal swab to test anal HPV with a PCR POCT capable of detecting 14 high-risk HPV genotypes. Anonymous questionnaires on self-sampling feasibility were completed. Participants were then referred to local clinics to undergo standard viral genotyping. Concordance between POCT and gold-standard test was measured with absolute agreement and Cohen's kappa. Receiver operating characteristic (ROC) curves were used to calculate POCT sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). RESULTS: 179 subjects got a valid POCT result, most of them men (98.3%) and men who have sex with men (90.4%). 68.2% tested positive for at least one high-risk HPV genotype on POCT. 150 feasibility questionnaires were collected: 92.7% of compilers found the self-swab easy to perform. For 178 subjects, a gold-standard test valid result was also available: 77% tested positive for at least one high-risk HPV genotype. The median time elapsed between the two tests was 9.8 months, due to COVID-19-related service interruptions. Agreement between POCT and gold-standard test was 79.3% (Cohen's kappa=0.49). POCT showed a sensitivity of 81.0%, a specificity of 73.8%, a PPV of 91.0% and an NPV of 54.4%. CONCLUSIONS: POCT showed a moderate agreement with gold-standard test and a discrete sensitivity and specificity, suggesting that it could be a useful and feasible additional tool for HPV screening, especially in low-resource and community-based settings.

Do we Still Need Eligibility Criteria to Recommend PrEP? Impact of National Prescribing Requirements on Retention in Care and Sexually Transmitted Infections Acquisition.

Italian guidelines recommend HIV pre-exposure prophylaxis (PrEP) only upon satisfying strict eligibility criteria. The objective of this study is to evaluate if PrEP candidates attending a community-based service comply with these criteria and whether these prescribing conditions affect retention in care and sexually transmitted infections (STIs) acquisition. A retrospective analysis was performed on PrEP candidates evaluated from January 2019 to June 2022. Data were collected from self-administered questionnaires and clinical files. The population was divided in subjects with 0/1 (0/1 C) and ≥ 2 (≥ 2 C) criteria. Descriptive statistics and non-parametric tests were employed to describe study population. Incidence of PrEP discontinuation and of STIs was estimated per 100 persons-year of follow up (PYFU), and incidence rate ratio (IRR) was calculated. Univariate and multivariable Cox regression analyses were used to evaluate the association strength between PrEP drop out and other variables. The analyses enrolled 659 individuals: 422 individuals were included in 0/1 C, 237 in ≥ 2 C group, respectively. Inconsistent condom use was the most reported prescribing criteria (399 individuals, 60.6%), followed by a previous STI (186 individuals, 28.2%). 0/1 C exhibited lower STIs incidence. PrEP discontinuation was 29% in 0/1 C and 38% in ≥ 2 C (p = 0.031). Cox model revealed that inconsistent condom use was the only prescribing criteria associated to PrEP persistence. The majority of PrEP candidate did not comply with prescribing conditions. Eligibility criteria failed to identify individuals with better retention in care. Our results suggest that Italian guidelines should be updated removing barriers to prescription.

Detection of Asymptomatic Mpox Carriers among High-Ri Men Who Have Sex with Men: A Prospective Analysis.

Mpox is traditionally considered a zoonotic disease with endemic circulation in Africa, but the 2022-2023 outbreak reached an unprecedented high number of cases in non-endemic countries, so that it was declared a public health emergency of international concern. The reasons for this extensive global spread, characterized by sexual transmission amongst men who have sex with men (MSM), have not been fully clarified. The existence of asymptomatic carriers with viable viral shedding might be an explanation and is under-debated after retrospective studies suggested that infection without symptoms might have a prevalence of 6.5%. We aimed to prospectively assess the presence of mpox infection in asymptomatic high-risk MSM using HIV pre-exposure prophylaxis and living with HIV. We selected individuals with no signs of active infection nor suggestive symptoms in the previous 21 days. Eligible individuals collected oral and anal swabs to undergo point-of-care testing for mpox and completed a 21-days follow-up. Seventy-two individuals were enrolled, and none tested positive for mpox infection nor developed symptoms during follow-up. We selected a high-risk population with a significant history of sexual exposure, but we failed to detect any asymptomatic infection. This observation might have important consequences in terms of contact management and epidemic control.

HIV-Indicator Condition Guided Testing in a Hospital Setting.

Late diagnosis is still a major issue in HIV infection management, leading to important consequences for both patients and community. In this perspective, HIV screening targeted on some clinical conditions (HIV indicator conditions-HIVICs) emerged as a useful strategy, also involving patients not considered at high behavioral risk. We organized an in-hospital HIVICs guided screening campaign named ICEBERG in Milan, Italy, between 2019 and 2021. Among the 520 subjects enrolled, mainly presenting with viral hepatitis or mononucleosis-like syndrome, 20 resulted HIV positive (3.8% prevalence). A significant proportion of them had multiple conditions and advanced immunosuppression, with 40% being AIDS-presenters. As adherence to the screening campaign was modest for non-ID specialists, educational interventions to raise clinicians' sensitivity are urgently needed. HIV-ICs guided testing was confirmed as a useful tool, but a combined approach with other screening strategies seems to be essential for early HIV diagnosis.

Gamma-Delta T-Cell Phenotype and Function in DAA-Treated HIV-HCV Co-Infected and HCV-Mono-Infected Subjects.

HIV-HCV co-infected subjects are at risk of liver fibrosis which may be linked to immune imbalances. Direct-acting antivirals (DAAs) represent the mainstay of HCV treatment in co-infected individuals, yet their effects on immune cell populations playing a role in fibrogenesis is unknown. We assessed γδ T-cell phenotype and function, Treg and Th17 frequencies, as well as γ-globulins and B-cell activation in 47 HIV-HCV co-infected and 35 HCV mono-infected individuals prior to and following DAA treatment (SVR12). Γδ T-cell activation decreased in both groups yet persisted at higher levels in the HIV-HCV co-infected subjects. No differences were registered in terms of γδT-cell function. Of note, the Vδ2/Th17 ratio, inversely linked to liver damage, increased significantly in the two groups upon treatment, yet a negative correlation between the Vδ2/Th17 ratio and liver function enzymes was found in the co-infected subjects alone. B-cell activation and γ-globulin levels decreased in both settings, yet B-cell activation remained higher in the HIV-HCV co-infected individuals. In HIV-HCV co-infected and HCV mono-infected participants, the effect of DAA was limited to γδ T- and B-cell activation as well as γ-globulin concentrations and the Vδ2/Th17 ratio, with no changes in γδ T-cell function and Treg frequencies. Importantly, γδ T- and B-cell activation remained at higher levels in the co-infected individuals than in those with HCV mono-infection alone. The persistence of such alterations within these cell subsets may be associated with the risk of hepatic and extrahepatic complications.

Real World Estimate of Vaccination Protection in Individuals Hospitalized for COVID-19.

Whether vaccination confers a protective effect against progression after hospital admission for COVID-19 remains to be elucidated. Observational study including all the patients admitted to San Paolo Hospital in Milan for COVID-19 in 2021. Previous vaccination was categorized as: none, one dose, full vaccination (two or three doses >14 days before symptoms onset). Data were collected at hospital admission, including demographic and clinical variables, age-unadjusted Charlson Comorbidity index (CCI). The highest intensity of ventilation during hospitalization was registered. The endpoints were in-hospital death (primary) and mechanical ventilation/death (secondary). Survival analysis was conducted by means of Kaplan-Meier curves and Cox regression models. Effect measure modification by age was formally tested. We included 956 patients: 151 (16%) fully vaccinated (18 also third dose), 62 (7%) one dose vaccinated, 743 (78%) unvaccinated. People fully vaccinated were older and suffering from more comorbidities than unvaccinated. By 28 days, the risk of death was of 35.9% (95%CI: 30.1−41.7) in unvaccinated, 41.5% (24.5−58.5) in one dose and 28.4% (18.2−38.5) in fully vaccinated (p = 0.63). After controlling for age, ethnicity, CCI and month of admission, fully vaccinated participants showed a risk reduction of 50% for both in-hospital death, AHR 0.50 (95%CI: 0.30−0.84) and for mechanical ventilation or death, AHR 0.49 (95%CI: 0.35−0.69) compared to unvaccinated, regardless of age (interaction p > 0.56). Fully vaccinated individuals in whom vaccine failed to keep them out of hospital, appeared to be protected against critical disease or death when compared to non-vaccinated. These data support universal COVID-19 vaccination.

Declining Mortality Rate of Hospitalised Patients in the Second Wave of the COVID-19 Epidemics in Italy: Risk Factors and the Age-Specific Patterns.

BACKGROUND: Mortality rate from COVID-19 in Italy is among the world's highest. We aimed to ascertain whether there was any reduction of in-hospital mortality in patients hospitalised for COVID-19 in the second-wave period (October 2020-January 2021) compared to the first one (February-May 2020); further, we verified whether there were clusters of hospitalised patients who particularly benefitted from reduced mortality rate. METHODS: Data collected related to in-patients' demographics, clinical, laboratory, therapies and outcome. Primary end-point was time to in-hospital death. Factors associated were evaluated by uni- and multivariable analyses. A flow diagram was created to determine the rate of in-hospital death according to individual and disease characteristics. RESULTS: A total of 1561 patients were included. The 14-day cumulative incidence of in-hospital death by competing risk regression was of 24.8% (95% CI: 21.3-28.5) and 15.9% (95% CI: 13.7-18.2) in the first and second wave. We observed that the highest relative reduction of death from first to second wave (more than 47%) occurred mainly in the clusters of patients younger than 70 years. CONCLUSIONS: Progress in care and supporting therapies did affect population over 70 years to a lesser extent. Preventive and vaccination campaigns should focus on individuals whose risk of death from COVID-19 remains high.

The importance of patients' case-mix for the correct interpretation of the hospital fatality rate in COVID-19 disease.

OBJECTIVE: We aimed to document data on the epidemiology and factors associated with clinical course leading to death of patients hospitalised with COVID-19. METHODS: Prospective observational cohort study on patients hospitalised with COVID-19 disease in February-24th/May-17th 2020 in Milan, Italy. Uni-multivariable Cox regression analyses were performed. Death's percentage by two-weeks' intervals according to age and disease severity was analysed. RESULTS: A total of 174/539 (32.3%) patients died in hospital over 8228 person-day follow-up; the 14-day Kaplan-Meier probability of death was 29.5% (95%CI: 25.5-34.0). Older age, burden of comorbidities, COVID-19 disease severity, inflammatory markers at admission were independent predictors of increased risk, while several drug-combinations were predictors of reduced risk of in-hospital death. The highest fatality rate, 36.5%, occurred during the 2nd-3rd week of March, when 55.4% of patients presented with severe disease, while a second peak, by the end of April, was related to the admission of older patients (55% ≥80 years) with less severe disease, 30% coming from long-term care facilities. CONCLUSIONS: The unusual fatality rate in our setting is likely to be related to age and the clinical conditions of our patients. These findings may be useful to better allocate resources of the national healthcare system, in case of re-intensification of COVID-19 epidemics.

A Comparison of Tenofovir Predose Concentrations in Generic Pre-exposure Prophylaxis Formulations: A Short Communication.

BACKGROUND: There is extensive evidence to show that pre-exposure prophylaxis (PrEP) using tenofovir disoproxil fumarate (TDF)-based formulations dramatically reduces the risk of HIV acquisition among individuals without HIV infection. Here, the authors aim to compare tenofovir plasma predose concentrations in subjects taking PrEP daily versus on demand and using different TDF-based generic formulations. METHODS: Subjects providing informed signed consent for the measurement of tenofovir plasma levels were included in the study. Predose drug concentrations were stratified according to PrEP administration and the type of TDF-based formulation. The control group consisted of patients with HIV infection who were matched for renal function and were administered branded TDF that was not combined with boosted-antiretroviral drugs. RESULTS: The study consisted of 100 subjects (mean age, 39 ± 10 years; body weight, 77 ± 11 kg). A wide distribution in tenofovir predose concentrations was observed, with values ranging from 17 to 297 ng/mL (coefficient of variation 77%). No significant differences were noted in tenofovir predose concentrations between subjects who were administered PrEP daily (n = 75) or on demand (n = 25) [94 (35-255) versus 104 (37-287) ng/mL; P = 0.476]. Comparable tenofovir predose concentrations were found between patients with HIV infection (n = 220) who were administered branded TDF and those without HIV infection who were treated with 5 different generic TDF-based formulations with generics-to-branded ratios. These were always within the range of 80%-125% and were used to define bioequivalence. CONCLUSIONS: The marketed generic formulations of TDF delivered tenofovir plasma predose concentrations comparable with those delivered by branded formulations.

Comparison of three therapeutic regimens for genotype-3 hepatitis C virus infection in a large real-life multicentre cohort.

BACKGROUND & AIMS: In the direct-acting antiviral era, treatment of genotype-3 HCV (HCV-GT3) is still challenging. Real-life comparisons between recommended regimens, sofosbuvir (SOF)+daclatasvir (DAC), SOF/velpatasvir (VEL), glecaprevir/pibrentasvir (GLE/PIB), are scarce. We aimed at filling this data gap. METHODS: Sustained virological response 12 weeks after treatment completion (SVR12) was assessed for all HCV-GT3 patients consecutively treated within the Lombardia web-based Navigatore HCV-Network; differences in SVR12 across regimens were evaluated by logistic regression. RESULTS: Of the 2082 subjects with HCV-GT3, 1544 were evaluable for comparisons between regimens: SOF + DAC (1023, 66.2%), SOF/VEL (369, 23.9%), GLE/PIB (152, 9.8%). Patients treated with former regimens were more frequently male, cirrhotic, HIV-positive, pretreated, used ribavirin in their regimen, and had lower baseline HCV-RNA. SVR12 was similar across groups: 94.8% in SOF + DAC, 97.6% in SOF/VEL, 96.7% in GLE/PIB (P = .065). At univariate analysis, SVR12 was associated with female gender (97.9% vs 94.8%, P = .007) and lower median pretreatment Log10 HCV-RNA (5.87 vs 6.20, P = .001). At multivariate logistic regression analysis, treatment with SOF/VEL was associated with a higher likelihood of SVR12 than SOF + DAC, but only in the absence of ribavirin (98% vs 90.3%). Female gender and lower pretreatment HCV-RNA were independently associated with SVR12. CONCLUSIONS: In a large real-life setting of HCV-GT3-infected patients with a high proportion of cirrhosis, the success rate was remarkable. The slight advantage of SOF/VEL on SOF + DAC was significant only without ribavirin. The current prescription shift towards novel regimens (ie SOF/VEL and GLE/PIB) in easier-to-treat patients allows ribavirin-free and shorter schedules without mining SVR12 in this <> genotype.

Real-world effectiveness and safety of glecaprevir/pibrentasvir in 723 patients with chronic hepatitis C.

BACKGROUND AND AIMS: The efficacy and safety of glecaprevir/pibrentasvir (G/P) for patients infected with hepatitis C virus (HCV) have only been investigated in clinical trials, with no real-world data currently available. The aim of our study was to investigate the effectiveness and safety of G/P in a real-world setting. METHODS: All patients with HCV consecutively starting G/P between October 2017 and January 2018 within the NAVIGATORE-Lombardia Network were analyzed. G/P was administered according to drug label (8, 12 or 16 weeks). Fibrosis was staged either histologically or by liver stiffness measurement. Sustained virological response (SVR) was defined as undetectable HCV-RNA 12 weeks after the end of treatment. RESULTS: A total of 723 patients (50% males) were treated with G/P, 89% for 8 weeks. The median age of our cohort was 58 years, with a median body mass index of 23.9 kg/m2, and median liver stiffness measurement of 6.1 kPa; 84% were F0-2 and 16% were interferon-experienced. Median HCV-RNA was 1,102,600 IU/ml, and 49% of patients had HCV genotype 1 (32% 1b), 28% genotype 2, 10% genotype 3 and 13% genotype 4. The median estimated glomerular filtration rate was 90.2 ml/min, platelet count 209x103/mm3 and albumin 4.3 g/dl. The SVR rates were 94% in intention-to-treat and 99.3% in per protocol analysis (8-week vs. 12 or 16-week: 99.2% vs. 100%). Five patients failed therapy because of post-treatment relapse; a post-treatment NS5A resistance-associated substitution was detected in 1 case. SVR rates were lower in males (p = 0.002) and in HCV genotype-3 (p = 0.046) patients treated for 8 weeks, but independent of treatment duration, fibrosis stage, baseline HCV-RNA, HIV co-infection, chronic kidney disease stage and viral kinetics. Mild adverse events were reported in 8.3% of the patients, and 0.7% of them prematurely withdrew treatment. Three patients died of drug-unrelated causes. CONCLUSIONS: In a large real-world cohort of Italian patients, we confirmed the excellent effectiveness and safety of G/P administered for 8, 12 or 16 weeks. LAY SUMMARY: A large number of patients with hepatitis C virus have been treated with glecaprevir/pibrentasvir (G/P) within the NAVIGATORE-Lombardia Network, in Italy. This is the first real-world study evaluating effectiveness and safety of G/P in patients with hepatitis C virus treated according to international recommendations. This study demonstrated excellent effectiveness (with sustained virological response rates of 99.3%) and safety profiles.

Leishmania infection can hamper immune recovery in virologically suppressed HIV-infected patients.

An HIV-infected patient started combination antiretroviral therapy with 13 CD4+ cells/microL. Despite sustained virological suppression over the following four years, the anemia did not resolve, and the CD4+ cell counts always remained below 200/microL until co-infection with Leishmania was diagnosed in October 2006 when the patient started complaining of persistent mild fever and asthenia. Once treatment for leishmaniasis was started with miltefosine, CD4+ cell count rose above 400/microL. A new drop in CD4+ cell count was observed when Leishmania DNA turned out again to be positive, but treatment with liposomal amphotericin-B restored immune recovery.

Rate of cirrhosis progression reduced in HIV/HCV co-infected non-responders to anti-HCV therapy.

This is a retrospective longitudinal follow-up study of 25 HIV/HCV positive cirrhotic patients not responding to peg-IFN plus ribavirin, and 25 untreated controls matched for age (+/-5 years), gender and Child-Pugh score. The primary endpoint of the study was the incidence of cirrhosis progression (CP) defined as the occurrence of at least one of the following events: death, ascites, jaundice, encephalopathy, gastrointestinal bleeding and hepatocellular carcinoma (HCC). During the median follow-up of 54 months (34-89), four treated (16%) and 13 untreated patients (52%) experienced CP (p = 0.02). Poisson's regression model showed that the independent predictors of CP were Peg-IFN therapy (p = 0.016), positive HIV-RNA (p = 0.024), and altered ALP values (p = 0.012). Peg-IFN therapy seems to slow down the rate of cirrhosis progression also in HIV/HCV co-infected patients nonresponders to anti-HCV therapy, in comparison with untreated patients.

Liver function parameters in HIV/HCV co-infected patients treated with amprenavir and ritonavir and correlation with plasma levels.

Acute liver toxicity is a frequent adverse event that occurs during antiretroviral therapy and was observed in 6-30% of the patients on treatment, especially in presence of HCV coinfection (Cooper et al., 2002, Maida et al., 2006, Sulkowski et al., 2000). A correlation between HCV-associated liver-fibrosis severity and the risk of HAART associated hepatoxicity has been demonstrated (Aranzabal et al., 2005, Sulkowski et al., 2004). This high liver toxicity rate might be due to increased drug exposure in patients with liver disease (Veronese et al., 2000). It has been reported that patients with chronic hepatitis C show significantly reduced CPY3A4 and CYP2D6 activity in comparison with healthy volunteers (Becquemont et al., 2002). The aim of this study was to evaluate the liver function tests in HCV-co-infected patients treated with fos-amprenavir and ritonavir.

Amprenavir and ritonavir plasma concentrations in HIV-infected patients treated with fosamprenavir/ritonavir with various degrees of liver impairment.

OBJECTIVES: The purpose of this study was to evaluate the steady-state pharmacokinetics of amprenavir and ritonavir in HIV-infected patients with different degrees of hepatic impairment. METHODS: HIV-positive patients receiving fosamprenavir/ritonavir (700/100 mg twice daily) were included. Patients were classified into three groups: (i) chronic hepatitis; (ii) liver cirrhosis; (iii) normal liver function. Serial blood samples for steady-state amprenavir and ritonavir pharmacokinetics (>14 days on treatment) were collected in the fasting state before the morning dose (C(trough)) and then 1, 2, 3, 4, 6, 8, 10 and 12 h after drug intake. Amprenavir and ritonavir plasma concentrations were determined by HPLC. RESULTS: Twenty-one HIV-infected patients were included. Seven had chronic hepatitis, eight had liver cirrhosis and six patients were in the control group. Amprenavir AUC(0-12), AUC(0-infinity), C(max) and C(ss) were increased by 50% to 60% in the cirrhotic group when compared with controls, whereas CL/F was decreased by 40%. Patients with chronic hepatitis showed a significant increase in AUC(0-12), C(max) and C(ss) values when compared with controls. Ritonavir pharmacokinetics was different only in cirrhotic patients when compared with controls. Liver function parameters at weeks 4, 12 and 24 were not different from baseline in any of the groups. Overall, a significant correlation between amprenavir AUC(0-12) and total bilirubin values on the day of pharmacokinetic analysis was found (r = 0.64, P = 0.003). CONCLUSIONS: On the basis of these data and also of data available in the literature, it seems reasonable to adapt the dose of fosamprenavir and/or ritonavir exclusively in the presence of adverse events, possibly related to protease inhibitors (i.e. liver toxicity), in subjects with high drug plasma levels. Therapeutic drug monitoring is advised in the management of these patients.

Naive HIV/HCV-coinfected patients have higher intrahepatic pro-inflammatory cytokines than coinfected patients treated with antiretroviral therapy.

In the era of antiretroviral therapy, liver disease has emerged as an important cause of morbidity and mortality in HIV/hepatitis C virus (HCV) coinfected patients. It is believed that HCV is a non-cytopathic virus and that T-cell-mediated events (including the production of pro-inflammatory cytokines) have an important role in promoting both liver damage and viral clearance. Whether HIV coinfection or antiretroviral therapies influence such events is still unclear. In the current study, we compared the expression of NKp46 (a natural killer cell marker), CD3 (a T-cell marker), interferon-gamma (IFN-gamma), tumour-necrosis factor-alpha (TNF-alpha; pro-inflammatory cytokines) and interleukin-10 (IL-10; an anti-inflammatory cytokine) mRNA in the liver of naive HIV/HCV-coinfected patients (group one, n=14), coinfected patients treated with antiretroviral therapy (group two, n=23) and naive HCV mono-infected patients (group three, n=24). All three groups had comparable HCV viremia, with coinfected patients showing similar and relatively high CD4+ T-cell counts and significantly different HIV vireamia. Interestingly, when compared to groups two and three, group one showed significantly higher intrahepatic mRNA levels for CD3, IFN-gamma and TNF-alpha, whereas the expression of NKp46 and IL-10 were comparable in all three groups. Further, higher histopathological grading scores within each group were independently associated with higher mRNA contents for CD3 and IFN-gamma and higher serum alanine aminotransferase levels at the time of liver biopsy. Together, these results suggest that HIV infection may exacerbate the immune-mediated inflammatory response in the liver of patients chronically infected with HCV and antiretroviral therapy may prevent this effect.

The 118I reverse transcriptase mutation is the only independent genotypic predictor of virologic failure to a stavudine-containing salvage therapy in HIV-1-infected patients.

Patients infected with HIV-1 with more than 1000 HIV-1 RNA copies/mL, who were genotyped within 3 months before starting stavudine and treated for at least 3 months with a stable stavudine-containing highly active antiretroviral therapy, were selected from our database to identify the determinants of response to stavudine. Nonresponse was defined as a failure to achieve HIV-1 RNA level of less than 400 copies/mL or a reduction of more than 2 log10 by week 12. Univariate logistic analysis was used to elicit the failure-associated reverse transcriptase mutations (scored 1 to develop a genotype score). Eighty-one patients were eligible for the analysis, including 75 (93%) who previously received zidovudine. Thirty-five (43%) were nonresponders. Univariate logistic analysis revealed the following failure-associated mutations: 41L (P = 0.0001), 44D (P = 0.02), 118I (P = 0.0006), 184V (P = 0.04), 210W (P = 0.0004), and 215Y (P = 0.002) for a median stavudine score of 2. Failure was observed in 7 (18.9%) of 37 patients with a score less than 2, compared with 28 (63.6%) of 44 patients with a score of 2 or greater (P < 0.0001). The multivariable analysis showed that the 118I mutation (P = 0.04) was the only independent genotypic predictor of failing on a stavudine- containing highly active antiretroviral therapy.