Encephalitis and aseptic meningitis: short-term and long-term outcome, quality of life and neuropsychological functioning.

For those surviving encephalitis, the influence on daily life of patients and their relatives may be substantial. In contrast, the prognosis after aseptic meningitis (ASM) is considered good. In this prospective study in patients with encephalitis (n = 20) and ASM (n = 46), we show that both groups experienced reduced Health Related Quality of Life (HRQoL) at two months after discharge, and that workability was reduced in 37% of the patients with ASM. However, 12 months after discharge no neuropsychological deficits were detected in the ASM group, whereas patients with encephalitis had lower scores on tests of fine motor and psychomotor skills as well as on learning and memory. We also found that for patients with encephalitis, neopterin, as a marker of Th1 cell induced macrophage activation, and a putatively neurotoxic ratio of the kynurenine pathway (KP) measured during the acute phase was associated with lower HRQoL. Our data show that not only encephalitis, but also ASM has substantial short-term influence on HRQoL and workability. For patients with encephalitis we suggest a link between immune activation and activation of the KP during the acute phase with impaired HRQoL.

To what extent can clinical characteristics be used to distinguish encephalitis from encephalopathy of other causes? Results from a prospective observational study.

BACKGROUND: Recognizing patients with encephalitis may be challenging. The cardinal symptom, encephalopathy, has a wide array of differential diagnoses. In this prospective study we aimed to explore the etiology of encephalitis and to assess the diagnostic accuracy of symptoms and clinical findings in patients with encephalitis in an encephalopathic population. METHODS: Patients with acute onset of encephalopathy (n = 136) were prospectively enrolled from January 2014-December 2015 at Oslo University Hospital, Ullevaal. Clinical and biochemical characteristics of patients who met the case definition of encephalitis were compared to patients with encephalopathy of other causes. RESULTS: Among 136 patients with encephalopathy, 19 (14%) met the case-definition of encephalitis. For 117 patients other causes of encephalopathy were found, infection outside the CNS was the most common differential diagnosis. Etiology of encephalitis was confirmed in 53% (4 bacterial, 4 viral, 1 parasitic, and 1 autoimmune). Personality change, nausea, fever, focal neurology, recent travel history, and low inflammation markers were significantly more abundant in patients with encephalitis, but the diagnostic accuracy for individual parameters were low (area under the curve (AUC) < 0.7). The combination of fever (OR = 6.6, 95% CI, 1.6-28), nausea (OR = 8.9, 95% CI, 1.7-46) and a normal level of ESR (erythrocyte sedimentation rate < 17 mm/hr, OR = 6.9, 95% CI, 1.5-33) was significant in multivariate analysis with an AUC (area under the curve) of 0.85 (95% CI, 0.76-0.94). Moderately increased pleocytosis in CSF (5-100 × 106/L) further increased the diagnostic accuracy of this combination, AUC 0.90 (95% CI, 0.81-0.98). CONCLUSIONS: There is a wide diversity in differential diagnoses in patients with encephalopathy, and no single symptom or finding can be used to predict encephalitis with high accuracy in this group. The combination of fever, nausea and a low ESR in an encephalopathic population, increased the diagnostic accuracy of encephalitis compared to solitary parameters. The triad could be a useful clinical tool for early diagnosis of encephalitis, and these patients should be considered for further diagnostics such as lumbar puncture (LP).

High neopterin and IP-10 levels in cerebrospinal fluid are associated with neurotoxic tryptophan metabolites in acute central nervous system infections.

BACKGROUND: The host response to intruders in the central nervous system (CNS) may be beneficial but could also be harmful and responsible for neurologic symptoms and sequelae in CNS infections. This immune response induces the activation of the kynurenine pathway (KP) with the production of neuroactive metabolites. Herein, we explored cytokine and KP responses in cerebrospinal fluid (CSF) and serum in patients with encephalitis, aseptic, and bacterial meningitis. METHODS: Cytokines were measured in CSF and serum by multiplex assay in adult patients with encephalitis of infectious, autoimmune or unknown etiology (n = 10), aseptic meningitis (ASM, n = 25), acute bacterial meningitis (ABM, n = 6), and disease control patients with similar symptoms but without pleocytosis in CSF (n = 42). Liquid chromatography-tandem mass spectrometry (LC-MS/ MS) was used to measure KP metabolites in CSF and serum. RESULTS: A characteristic pattern of increasing cytokine levels and KP metabolites was found in CSF from encephalitis to ASM, with the highest levels in ABM. In ASM and ABM, most inflammatory mediators, including IL-6, IL-8, and IFN-inducible protein-10 (IP-10), showed markedly elevated levels in CSF compared with serum, indicating production within the CNS. In contrast to most mediators, the highest level of IP-10 was found in the ASM group, suggesting a potential role for IP-10 in aseptic/viral meningitis. Neopterin and IP-10 were associated with marked changes in KP metabolites in CSF with increasing kynurenine/tryptophan ratio reflecting indoleamine 2,3-dioxygenase activity. Neopterin, a marker of IFN-γ activity, was associated with an unfavorable balance between neuroprotective and neurotoxic tryptophan metabolites. CONCLUSION: We show that parenchymal and meningeal inflammations in CNS share a characteristic cytokine profile with a general immune response in the CSF with limited influence from the systemic circulation. IFN-γ activity, assessed by neopterin and IP-10 levels, may play a role in the activation of the KP pathway in these patients, potentially mediating neurotoxic effects.

Pneumococcal sepsis requiring mechanical ventilation: Cohort study in 38 patients with rapid progression to septic shock.

BACKGROUND: The aim was to study the course of severe pneumococcal sepsis in patients who rapidly developed septic shock with multiorgan failure. METHODS: Combined retrospective and prospective cohort study of all patients with pneumococcal sepsis requiring mechanical ventilation admitted to our Medical Intensive Care Unit at Oslo University Hospital Ullevaal, during an 8-year period (01 January 2006 to 31 December 2013). The inclusion criteria were growth of Streptococcus pneumoniae in blood culture and respiratory failure treated with invasive mechanical ventilation. RESULTS: Thirty-eight patients were included. Median age was 57 years (interquartile range 49-68, range 22-79). For 84% (32/38), it took <24 hours from the first medical evaluation until they were in septic shock. Initial clinical features were variable; none were treated with antibiotics before hospital admission. Median Sequential Organ Failure Assessment (SOFA) score at admission was 11 (range 1-15) and maximum 15 (range 5-22), all patients developed multiorgan failure. Mutilating complications were seen in 47% (18/38) of the patients: six with amputations, 11 had adverse neurological complications and one patient both. In-hospital mortality was 40% (15/38), 20% (8/38) survived with sequelae and 40% (15/38) returned to their habitual state. Poor outcome was associated with meningitis, disseminated intravascular coagulation, and gastrointestinal symptoms. CONCLUSION: In this patient cohort with pneumococcal sepsis and respiratory failure rapid development of septic shock was seen in all cases, even in young healthy individuals. Initial clinical features were variable; none were treated with antibiotics before admission. Mortality was high (40%), as was morbidity with limb amputations and neurological complications.

Where is the greatest impact of uncontrolled HIV infection on AIDS and non-AIDS events in HIV?

OBJECTIVE: The extent to which controlled and uncontrolled HIV interact with ageing, European region of care and calendar year of follow-up is largely unknown. METHOD: EuroSIDA participants were followed after 1 January 2001 and grouped according to current HIV progression risk; high risk (CD4 cell count ≤350/µl, viral load ≥10 000 copies/ml), low risk (CD4 cell count ≥500 cells/µl, viral load <50 copies/ml) and intermediate (other combinations). Poisson regression investigated interactions between HIV progression risk, age, European region of care and year of follow-up and incidence of AIDS or non-AIDS events. RESULTS: A total of 16 839 persons were included with 136 688 person-years of follow-up. In persons aged 30 years or less, those at high risk had a six-fold increased incidence of non-AIDS compared with those at low risk, compared with a two-to-three-fold increase in older persons (P = 0.0004, interaction). In Eastern Europe, those at highest risk of non-AIDS had a 12-fold increased incidence compared with a two-to-four-fold difference in all other regions (P = 0.0029, interaction). Those at high risk of non-AIDS during 2001-2004 had a two-fold increased incidence compared with those at low risk, increasing to a five-fold increase between 2013 and 2016 (P < 0.0001, interaction). Differences among high, intermediate and low risk of AIDS were similar across age groups, year of follow-up and Europe (P = 0.57, 0.060 and 0.090, respectively, interaction). CONCLUSION: Factors other than optimal control of HIV become increasingly important with ageing for predicting non-AIDS, whereas differences across Europe reflect differences in patient management as well as underlying socioeconomic circumstances. The differences between those at high, intermediate and low risk of non-AIDS between 2013 and 2016 likely reflects better quality of care.

Long term effectiveness of once-daily unboosted atazanavir plus abacavir/lamivudine as a switch strategy in subjects with virological suppression.

BACKGROUND: Use of unboosted atazanavir (ATV400) is approved in the US but not in Europe (1). Due to pharmacokinetic interactions it should not be used with tenofovir but can be used with abacavir/lamivudine (ABC/3TC) (1, 2) (3). Effectiveness data of ATV400+ABC/3TC as a switch strategy in clinical routine however are scant. METHODS: We evaluated treatment outcomes of ATV400+ABC/3TC in pre-treated subjects in the EuroSIDA cohort with undetectable HIV-1 RNA, and previous ABC experience or assumed previous HLA B57*01 testing. We performed a time to loss of virologic response (TLOVR below 50 c/mL) and a snapshot analysis at 48, 96 and 144 weeks. Virological failure (VF) was defined as a confirmed plasma HIV-1 RNA >50 c/mL. RESULTS: We included 258 subjects: 176 (68%) male, median age 46 (IQR 41, 53) y, 225 (87.2%) white, hepatitis virus co-infection 36%, median baseline CD4 at switch 540 cells (360, 700), time with VL≤ 50 c/mL 45 (24, 69) months. The median calendar year of switching was 2008 (2006, 2010). The 3rd drug in previous regimen was ATV/r in 70 (27.1%), other PI/r in 25 (9.7%), and other 163 (63.2%); 85 (32.9%) had previously failed with a PI. The virological response at 48/96/144 weeks was, respectively, 89.5 [95% CI 85.1, 92.9]/88 [83.4, 91.7]/86.3% [81.6, 90.4] (TLOVR, composite endpoint failure or stop for any reason) and the risk of VF was 8.3/7.6/7.6%. In the snapshot analysis HIV-RNA was below 50 c/mL in 72.5/65.9/51.6%, respectively, and >50 c/mL in 6.6/5.4/4.3%. Only 0.8/1.9/3.5% discontinued due to adverse events. There was a high rate of discontinuations due to other reasons or with VL missing in window. In a multivariate adjusted analysis, we observed an association between VF and nadir CD4 count (RH 0.60 [0.39, 0.93] per 100 cells higher), time with VL≤50 c/mL (RH 0.89 [0.81, 0.98] per 6 months longer) and previous failure with a PI (3.04 [1.36, 6.80]). There was no association with gender, age, hepatitis virus co-infection, CD4 count at time of switching or third drug used in the previous regimen. CONCLUSIONS: A switch to ATV400+ABC/3TC in selected subjects with HIV-RNA below 50 c/mL is associated with relatively low rates of VF and discontinuation due to adverse events. Use might be considered in those with long-term suppression and without prior PI failure. Larger cohorts are required to further define the appropriate selection criteria.

Deteriorating renal function and clinical outcomes in HIV-positive persons.

OBJECTIVES: To determine the relationship between measures of renal function [current estimated glomerular filtration rate (eGFR) and proportion of follow-up with a low eGFR (%FU ≤60 ml/min)] and fatal/ nonfatal AIDS, non-AIDS events and all-cause mortality. DESIGN: An observational, longitudinal cohort study of 12 155 persons from EuroSIDA. METHODS: Persons with at least one eGFR measurement after 1 January 2004, using the CKD-EPI formula, were included. Poisson regression analyses were used to determine whether current eGFR or %FU of 60 ml/min or less were independent prognostic markers for clinical events. RESULTS: During 61 425 person-years of follow-up (PYFU), the crude incidence of deaths was 11.1/1000 PYFU [95% confidence interval (CI) 10.0-12.1] at current eGFR more than 90 ml/min and 199.6 (95% CI 1144.3-254.3/1000 PYFU) when current eGFR was 30 ml/min or less. Corresponding figures for AIDS were 12.2 (11.1-13.3) and 63.9 (36.5-103.7) and for non-AIDS were 16.0 (14.8-17.3) and 203.6 (147.7-259.5). After adjustment, current eGFR of 30 ml/min or less was a strong predictor of death [adjusted incidence rate ratios (aIRR) 4.35; 95% CI 3.20-5.91] and non-AIDS events (3.63; 95% CI 2.57-5.13), although the relationship with AIDS was less strong (1.45; 95% CI 1.01-2.08). After adjustment, %FU of 60 ml/min or less was associated with a 22% increased incidence of death (aIRR 1.22 per 10% longer; 95% CI 1.18-1.27), a 13% increased incidence of non-AIDS events (95% CI 1.08-1.18) and a 15% increased incidence of AIDS events (95% CI 1.06-1.24). CONCLUSION: Both current eGFR and %FU of 60 ml/min or less were associated with death and non-AIDS events in HIV-positive persons. Our findings highlight the association between underlying renal dysfunction and morbidity and mortality in HIV infection, although reverse causality cannot be excluded.

Lopinavir/ritonavir, atazanavir/ritonavir, and efavirenz in antiretroviral-naïve HIV-1-infected individuals over 144 weeks: an open-label randomized controlled trial.

BACKGROUND: The objective of this study was to compare the efficacy of ritonavir boosted atazanavir versus ritonavir boosted lopinavir or efavirenz, all in combination with 2 nucleoside analogue reverse transcriptase inhibitors (NRTIs), over 144 weeks in antiretroviral-naïve HIV-1-infected individuals. METHODS: A prospective open-label randomized controlled trial was conducted at 29 sites in Sweden and Norway between April 2004 and December 2009. Patients were randomized to receive either efavirenz 600 mg once daily (EFV), or atazanavir 300 mg and ritonavir 100 mg once daily (AZV/r), or lopinavir 400 mg and ritonavir 100 mg twice daily (LPV/r). The primary endpoints were the proportion of patients with HIV-1 RNA < 50 copies/ml at 48 and 144 weeks. RESULTS: Of 245 patients enrolled, 243 were randomized and 239 received the allocated intervention: 77 EFV, 81 AZV/r, and 81 LPV/r. Median (interquartile range) CD4 cell counts at baseline were 150 (80-200), 170 (80-220), and 150 (90-216) per microlitre, respectively. At week 48 the proportion (95% confidence interval (CI)) of patients achieving HIV-1 RNA < 50 copies/ml was 86 (78-94)% in the EFV arm, 78 (69-87)% in the AZV/r arm and, 69 (59-78)% in the LPV/r arm in the intention-to-treat analysis. There was a significant difference between the EFV and LPV/r arm (p = 0.014). At week 144, the proportion (95% CI) of patients achieving HIV-1 RNA < 50 copies/ml was 61 (50-72)%, 58 (47-69)%, 51 (41-63)%, respectively (p = 0.8). Patients with CD4 cell counts of ≤ 200/µl or HIV-1 RNA > 100,000 copies/ml at baseline had similar response rates in all arms. CONCLUSION: EFV was superior to LPV/r at week 48, but there were no significant differences between the 3 arms in the long-term (144 weeks) follow-up.

External validation of the bilirubin-atazanavir nomogram for assessment of atazanavir plasma exposure in HIV-1-infected patients.

Atazanavir increases plasma bilirubin levels in a concentration-dependent manner. Due to less costly and readily available assays, bilirubin has been proposed as a marker of atazanavir exposure. In this work, a previously developed nomogram for detection of suboptimal atazanavir exposure is validated against external patient populations. The bilirubin nomogram was validated against 311 matching bilirubin and atazanavir samples from 166 HIV-1-infected Norwegian, French, and Italian patients on a ritonavir-boosted regimen. In addition, the nomogram was evaluated in 56 Italian patients on an unboosted regimen. The predictive properties of the nomogram were validated against observed atazanavir plasma concentrations. The use of the nomogram to detect non-adherence was also investigated by simulation. The bilirubin nomogram predicted suboptimal exposure in the patient populations on a ritonavir-boosted regimen with a negative predictive value of 97% (95% CI 95-100). The bilirubin nomogram and monitoring of atazanavir concentrations had similar predictive properties for detecting non-adherence based on simulations. Although both methods performed adequately during a period of non-adherence, they had lower predictive power to detect past non-adherence episodes. Using the bilirubin nomogram for detection of suboptimal atazanavir exposure in patients on a ritonavir-boosted regimen is a rapid and cost-effective alternative to routine measurements of the actual atazanavir exposure in plasma. Its application may be useful in clinical settings if atazanavir concentrations are not available.

Infectious encephalitis: a description of a Norwegian cohort.

BACKGROUND: Prompt recognition and rapid initiation of adequate treatment are important for the outcome of encephalitis. Despite extensive diagnostic testing, the causative agent often remains unknown. The aim of this study was to investigate in how many patients the causative agent was found. METHODS: Adults (≥ 18 y) diagnosed with ICD codes indicating encephalitis between 2000 and 2009 at Oslo University Hospital, Ullevål were retrospectively studied. Causative agents, clinical presentation, and demographic characteristics were registered. Those with an identified causative agent were compared to those for whom no agent could be found. RESULTS: Of 136 registered patients, 70 were included in the study. Sixty-six did not fulfil our inclusion criteria or were diagnosed with other, more probable conditions. The causative agent was found in 30/70 (43%) patients; herpes simplex type 1 (10/70, 14%) and varicella zoster virus (6/70, 9%) were the most frequently identified agents. A bacterial cause was found in 6/70 (9%). Patients with an identified agent were more often men and had been ill longer than those for whom no agent could be found. Computed tomography and magnetic resonance imaging were more likely to be abnormal in those patients where a causative agent was found. Five of the 70 (7%) patients died of the infection. The identification rate did not increase during the study period. CONCLUSIONS: The diagnosis of encephalitis remains a challenge, and in many patients no causative agent is found. Clinically, immune-mediated encephalitis cannot be differentiated from infectious encephalitis and represents an important differential diagnosis. More knowledge is needed to improve our diagnostic skills.

Non-linear mixed effects modeling of antiretroviral drug response after administration of lopinavir, atazanavir and efavirenz containing regimens to treatment-naïve HIV-1 infected patients.

The objective of this analysis was to compare three methods of handling HIV-RNA data below the limit of quantification (LOQ) when describing the time-course of antiretroviral drug response using a drug-disease model. Treatment naïve Scandinavian HIV-positive patients (n = 242) were randomized to one of three study arms. Two nucleoside reverse transcriptase inhibitors were administrated in combination with 400/100 mg lopinavir/ritonavir twice daily, 300/100 mg atazanavir/ritonavir once a day or 600 mg efavirenz once a day. The viral response was monitored at screening, baseline and at 1, 2, 3, 4, 12, 24, 48, 96, 120, and 144 weeks after study initiation. Data up to 400 days was fitted using a viral dynamics non-linear mixed effects drug-disease model in NONMEM. HIV-RNA data below LOQ of 50 copies/ml plasma (39%) was omitted, replaced by LOQ/2 or included in the analysis using a likelihood-based method (M3 method). Including data below LOQ using the M3 method substantially improved the model fit. The drug response parameter expressing the fractional inhibition of viral replication was on average (95% CI) estimated to 0.787 (0.721-0.864) for lopinavir and atazanavir treatment arms and 0.868 (0.796-0.923) for the efavirenz containing regimen. At 400 days after treatment initiation 90% (76-100) of the lopinavir and atazanavir treated patients were predicted to have undetectable viral levels and 96% (89-100%) for the efavirenz containing treatment. Including viral data below the LOQ rather than omitting or replacing data provides advantages such as better model predictions and less biased parameter estimates which are of importance when quantifying antiretroviral drug response.

Bilirubin-a potential marker of drug exposure in atazanavir-based antiretroviral therapy.

The objective of this work was to examine the atazanavir-bilirubin relationship using a population-based approach and to assess the possible application of bilirubin as a readily available marker of atazanavir exposure. A model of atazanavir exposure and its concentration-dependent effect on bilirubin levels was developed based on 200 atazanavir and 361 bilirubin samples from 82 patients receiving atazanavir in the NORTHIV trial. The pharmacokinetics was adequately described by a one-compartment model with first-order absorption and lag-time. The maximum inhibition of bilirubin elimination rate constant (I(max)) was estimated at 91% (95% CI, 87-94) and the atazanavir concentration resulting in half of I(max) (IC50) was 0.30 µmol/L (95% CI, 0.24-0.37). At an atazanavir/ritonavir dose of 300/100 mg given once daily, the bilirubin half-life was on average increased from 1.6 to 8.1 h. A nomogram, which can be used to indicate suboptimal atazanavir exposure and non-adherence, was constructed based on model simulations.

HIV type-1 drug resistance testing on dried blood spots is feasible and reliable in patients who fail antiretroviral therapy in rural Tanzania.

BACKGROUND: HIV type-1 (HIV-1) drug resistance testing is rarely available in resource-limited settings because of high costs and stringent requirements for storage and transport of plasma. Dried blood spots (DBS) can be a convenient alternative to plasma, but the use of DBS needs validation under field conditions. We assessed the performance of DBS in genotypic resistance testing of patients who failed first-line antiretroviral therapy (ART) in rural Tanzania. METHODS: A total of 36 ART-experienced patients with viral loads >1,000 copies/ml (median 15,180 copies/ml [range 1,350-3,683,000]) and with various HIV-1 subtypes were selected for resistance testing. DBS were stored with desiccant at ambient temperature for a median of 29 days (range 8-89). Samples were amplified using an in-house reverse transcriptase-nested PCR method and sequenced using the ViroSeq™ assay (Abbott Molecular, Des Plaines, IL, USA). DBS-derived genotypes were compared with genotypes from plasma. RESULTS: Overall, 34 of 36 (94%) DBS specimens were successfully genotyped. In the protease region, of 142 polymorphisms found in plasma, 132 (93%) were also detected in DBS. In the reverse transcriptase region, of 57 clinically relevant mutations present in plasma, 51 (89%) were also detected in DBS. A total of 30 of 34 (88%) patients had identical resistance profiles to antiretroviral drugs in plasma and DBS. CONCLUSIONS: Genotyping was successful in the vast majority of DBS specimens stored at ambient temperature for up to 3 months, and there was high concordance between mutations found in DBS and plasma. Our study suggests that DBS can be a feasible and reliable tool to monitor HIV-1 drug resistance in patients on ART in resource-limited settings.

Amnesia following herpes simplex encephalitis: diffusion-tensor imaging uncovers reduced integrity of normal-appearing white matter.

PURPOSE: To explore white matter (WM) and gray matter tissue integrity in the apparently unaffected hemisphere of patients with herpes simplex encephalitis (HSE) who have gross unilateral medial temporal lobe (MTL) lesions and both verbal and visuospatial memory deficits. MATERIALS AND METHODS: This study had institutional ethics committee approval and included written informed consent. Magnetic resonance (MR) imaging was performed in five patients who had recovered from HSE (one woman, four men; median age, 32 years; interquartile range, 28.5-37 years) and 51 age-matched controls (30 women, 21 men; median age, 32 years; interquartile range, 28-37 years). As markers of microstructural WM integrity, fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity, and radial diffusivity (RD) derived from diffusion-tensor (DT) imaging were used. An automated regional brain segmentation approach yielded estimates of subcortical volumes, including hippocampus, and cortical thickness. Group differences were evaluated by using permutation tests. RESULTS: Examination of standard MR images found unilateral lesions in all patients. The patients with HSE showed reduced FA and increased MD and RD in several WM tracts contralateral to lesions (P < .05, corrected for multiple comparisons). Affected tracts included connections between the MTLs and other parts of the brain. No significant group differences were observed in subcortical volume or cortical thickness. CONCLUSION: These results suggest that patients with HSE have reduced microstructural integrity of normal-appearing WM contralateral to grossly visible lesions. These subtle lesions, detectable at DT imaging, probably contribute to the memory impairment manifested by these patients. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.10100179/-/DC1.

Drug resistance is widespread among children who receive long-term antiretroviral treatment at a rural Tanzanian hospital.

OBJECTIVES: To assess long-term virological efficacy and the emergence of drug resistance in children who receive antiretroviral treatment (ART) in rural Tanzania. PATIENTS AND METHODS: Haydom Lutheran Hospital has provided ART to HIV-infected individuals since 2003. From February through May 2009, a cross-sectional virological efficacy survey was conducted among children (<15 years) who had completed >or=6 months of first-line non-nucleoside reverse transcriptase inhibitor (NNRTI)-based ART. Genotypic resistance was determined in those with a viral load of >200 copies/mL. RESULTS: Virological response was measured in 19 of 23 eligible children; 8 of 19 were girls and median age at ART initiation was 5 years (range 2-14 years). Median duration of ART at the time of the survey was 40 months (range 11-61 months). Only 8 children were virologically suppressed (50% harboured drug resistance. Results for children were markedly poorer than for adults attending the same programme, underscoring the need for improved treatment strategies for children in resource-limited settings.

Differential effects of efavirenz, lopinavir/r, and atazanavir/r on the initial viral decay rate in treatment naïve HIV-1-infected patients.

Initial viral decay rate may be useful when comparing the relative potency of antiretroviral regimens. Two hundred twenty-seven ART-naïve patients were randomized to receive efavirenz (EFV) (n = 74), lopinavir/ritonavir (LPV/r) (n = 77), or atazanavir/ritonavir (ATV/r) (n = 79) in combination with two NRTIs. The most frequently used NRTI combinations in the EFV and ATV/r groups were the nonthymidine analogues tenofovir and emtricitabine or lamivudine (70% and 68%, respectively) and, in the LPV/r group, lamivudine and the thymidine analogue zidovudine (89%). HIV-1 RNA was monitored during the first 28 days after treatment initiation. Phase 1 and 2 decay rate was estimated in a subset of 157 patients by RNA decrease from days 0 to 7, and days 14 to 28. One-way ANOVA and subsequent Tukey's post hoc tests were used for groupwise comparisons. Mean (95% CI) HIV-1 RNA reductions from days 0 to 28 were 2.59 (2.45-2.73), 2.42 (2.27-2.57), and 2.13 (2.01-2.25) log(10) copies/ml for the EFV-, LPV/r-, and ATV/r-based treatment groups, respectively, with a significantly larger decrease in the EFV-based group at all time points compared with ATV/r (p < 0.0001), and with LPV/r at days 7-21 (p < 0.0001-0.03). LPV/r gave a greater RNA decrease compared with ATV/r from day 14 (p = 0.02). Phase 1 decay rate was significantly higher in the EFV group compared with LPV/r (p = 0.003) or ATV/r (p < 0.0001). No difference was found in phase 2 decrease. EFV-based treatment gave a more rapid decline in HIV-1 RNA than did either of the boosted protease inhibitor-based regimens. The observed differences may reflect different inherent regimen potencies.

The relation between treatment outcome and efavirenz, atazanavir or lopinavir exposure in the NORTHIV trial of treatment-naïve HIV-1 infected patients.

PURPOSE: The relation between treatment outcome and trough plasma concentrations of efavirenz (EFV), atazanavir (ATV) and lopinavir (LPV) was studied in a pharmacokinetic/pharmacodynamic substudy of the NORTHIV trial-a randomised phase IV efficacy trial comparing antiretroviral-naïve human immunodeficiency virus-1-infected patients treated with (1) EFV + 2 nucleoside reverse transcriptase inhibitors (2NRTI) once daily, (2) ritonavir-boosted ATV + 2NRTI once daily or (3) ritonavir-boosted LPV + 2NRTI twice daily. The findings were related to the generally cited minimum effective concentration levels for the respective drugs (EFV 1,000 ng/ml, ATV 150 ng/ml, LPV 1,000 ng/ml). The relation between atazanavir-induced hyperbilirubinemia and virological efficacy was also studied. METHODS: Drug concentrations were sampled at weeks 4 and 48 and optionally at week 12 and analysed by high-performance liquid chromatography with UV detector. When necessary, trough values were imputed by assuming the reported average half-lives for the respective drugs. Outcomes up to week 48 are reported. RESULTS: No relation between plasma concentrations of EFV, ATV or LPV and virological failure, treatment withdrawal due to adverse effects or antiviral potency (viral load decline from baseline to week 4) was demonstrated. Very few samples were below the suggested minimum efficacy cut-offs, and their predictive value for treatment failure could not be validated. There was a trend toward an increased risk of virological failure in patients on ATV who had an average increase of serum bilirubin from baseline of <25 micromol/l. CONCLUSIONS: The great majority of treatment-naïve and adherent patients on standard doses of EFV, ritonavir-boosted ATV and ritonavir-boosted LPV have drug concentrations above that considered to deliver the maximum effect for the respective drug. The results do not support the use of routine therapeutic drug monitoring (TDM) for efficacy optimisation in treatment-naïve patients on these drugs, although TDM may still be of value in some cases of altered pharmacokinetics, adverse events or drug interactions. Serum bilirubin may be a useful marker of adherence to ATV therapy.

Tracing the HIV-1 subtype B mobility in Europe: a phylogeographic approach.

BACKGROUND: The prevalence and the origin of HIV-1 subtype B, the most prevalent circulating clade among the long-term residents in Europe, have been studied extensively. However the spatial diffusion of the epidemic from the perspective of the virus has not previously been traced. RESULTS: In the current study we inferred the migration history of HIV-1 subtype B by way of a phylogeography of viral sequences sampled from 16 European countries and Israel. Migration events were inferred from viral phylogenies by character reconstruction using parsimony. With regard to the spatial dispersal of the HIV subtype B sequences across viral phylogenies, in most of the countries in Europe the epidemic was introduced by multiple sources and subsequently spread within local networks. Poland provides an exception where most of the infections were the result of a single point introduction. According to the significant migratory pathways, we show that there are considerable differences across Europe. Specifically, Greece, Portugal, Serbia and Spain, provide sources shedding HIV-1; Austria, Belgium and Luxembourg, on the other hand, are migratory targets, while for Denmark, Germany, Italy, Israel, Norway, the Netherlands, Sweden, Switzerland and the UK we inferred significant bidirectional migration. For Poland no significant migratory pathways were inferred. CONCLUSION: Subtype B phylogeographies provide a new insight about the geographical distribution of viral lineages, as well as the significant pathways of virus dispersal across Europe, suggesting that intervention strategies should also address tourists, travellers and migrants.