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- Al-Saai, Salma, et al.
(författare)
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Distinct haplotypes of dhfr and dhps among Plasmodium falciparum isolates in an area of high level of sulfadoxine-pyrimethamine (SP) resistance in eastern Sudan
- 2009
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Ingår i: Infection, Genetics and Evolution. - : Elsevier BV. - 1567-1348 .- 1567-7257. ; 9:5, s. 778-783
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Tidskriftsartikel (refereegranskat)abstract
- Typing of polymorphic microsatellites that are linked to drug resistance genes has shed light on the origin and pattern of spread of some anti-malarial drugs. Recent surveys revealed spread of a high-level pyrimethemine resistant lineage of Plasmodium falciparum, of Asian origin, across Africa. Here, we examined mutations in dihydrofolate reductase, dhfr [chromsosome 4], the dihydropteroate synthase, dhps [chromosome 8] associated with resistance to sulfadoxine-pyrimethamine (SP), and neighboring microsatellites among P. falciparum isolates in Asar village, eastern Sudan. This area lies at the fringes of malaria endemicity, where the remote P. falciparum parasites have some distinct genetic characteristics. Overall, 89% (84/94) of the examined isolates carried double mutations at dhfr (N51I and S108N), but the 59R and I164L mutations were not seen. Similarly, the majority, 43% (35/81) of the isolates carried double mutations at dhps (437G, 540E). Analysis of neighboring microsatellites revealed one major dhfr haplotype with mutations (51I, 108N) and one dhps haplotype with mutations (436S, 437G, 540E). These haplotypes differ from the major ones thought to drive resistance to SP across Africa. The resistant haplotypes of dhfr and dhps, in Asar, share some microsatellites with the wild genotypes suggesting that they were generated locally. Among isolates successfully examined, 40% shared identical haplotypes of the 2 loci, comprising a dominant resistant lineage. Undoubtedly, this lineage plays an important role in clinical failure to SP in this area.
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- Kheir, Amany, et al.
(author)
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Fitness cost of drug resistance in malaria parasites
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Other publication (other academic/artistic)abstract
- Version:1.0 StartHTML:0000000186 EndHTML:0000006024 StartFragment:0000002654 EndFragment:0000005988 SourceURL:file://localhost/Users/gotes/Desktop/Amany%20disp/Paper%20IV-2011.doc @font-face { font-family: "Times New Roman"; }@font-face { font-family: "Times New Roman Italic"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }table.MsoNormalTable { font-size: 10pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; } Many field surveys have demonstrated a decline in the prevalence of drug resistant parasites following withdrawal of drugs, implying fitness cost of mutations causing resistance. However, for clear ethical reason, within-host dynamics of drug-resistant mutants and sensitive forms in the absence of the drug has not been investigated in nature. Here we monitored longevity of drug resistant Plasmodium falciparum parasites in a small village in eastern Sudan with a long dry period followed by a brief annual rains and appearance of Anopheles mosquitoes. This allows tracing the fate of drug resistant P. falciparum clones, in the absence of selective drug pressure, over a period of 7 to 8 months, in the dry season. Two cohorts were examined, (a) 83 patients enrolled in October 1993 and monitored to December 1994, and (b) 121 patients recruited in October 2001 and followed-up to December 2002. Patients in both cohorts were treated, on diagnosis, with chloroquine (25mg/kg) and then followed monthly, in each visit a blood sample was collected and a patient was treated only if fever and visible parasitaemia were detected. We used PCR and RT-PCR to detect parasites and gametocytes that persisted at sub-patent levels in the dry season, respectively. In addition, we examined alleles of genes controlling the response of P. falciparum to chloroquine; the chloroquine resistance transporter (Pfcrt76T) and the multi-drug resistance protein (Pfmdr186Y). A large proportion of both cohorts maintained gametocytes producing sub-patent asymptomatic P. falciparum infections throughout the dry season. Mutant alleles of Pfcrt76T reached fixation following CQ treatment and remained high in the transmission season, a reflection of selection. However, at the start of the dry season, wild type alleles of both genes (Pfcrt76K and Pfmdr186N) started to emerge and increased significantly in frequency as the season progressed. Some members of both cohorts, encountered malaria episode in the ensuing transmission season, all of them were found to harbour parasite with wild type alleles for both genes. The above data has clearly shown selective disadvantage of CQ resistant genotypes (Pfcrt76T, Pfmdr186Y) in the absence of the drug. The data were discussed in the context of fitness of drug resistant parasite and its epidemiological impact.
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- Alagaratnam, Jasmini, et al.
(author)
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Impact of interrupting antiretroviral therapy started during primary HIV-1 infection on plasma neurofilament light chain protein, a marker of neuronal injury: The SPARTAC trial
- 2024
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In: Journal of Virus Eradication. - 2055-6640 .- 2055-6659. ; 10:2
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Journal article (peer-reviewed)abstract
- Objective: Antiretroviral therapy (ART)-conferred suppression of HIV replication limits neuronal injury and inflammation. ART interruption tests efficacy in HIV cure trials and viral rebound after ART interruption may induce neuronal injury. We investigated the impact of protocol-defined ART interruption, commenced during primary HIV-1 infection (PHI) on a biomarker of neuro-axonal injury (neurofilament light protein (NfL)), and its associations with inflammation (D-dimer and interleukin-6 (IL-6)) and HIV-1 reservoir size (total HIV-1 DNA). Design: Retrospective study measuring plasma NfL in 83 participants enrolled in SPARTAC randomised to receive 48-weeks ART initiated during PHI, followed by ART interruption. Methods: NfL (Simoa immunoassay, Quanterix™) was measured before ART, after 48 weeks on ART, and 12 weeks after stopping ART. Plasma D-dimer and IL-6, and total HIV-1 DNA in peripheral CD4+ T-cells results were available in a subset of participants. Longitudinal NfL changes were assessed using mixed models, and associations with clinical and laboratory parameters using linear regression. Results: NfL decreased following 48-weeks ART (geometric mean 6.9 to 5.8 pg/mL, p = 0.006) with no further significant change up to 12-weeks post-stopping ART despite viral rebound in the majority of participants (median 1.7 to 3.9 plasma HIV-1 RNA log10 copies/mL). Higher baseline NfL was independently associated with higher plasma HIV-1 RNA (p = 0.020) and older age (p = 0.002). While NfL was positively associated with D-dimer (n = 48; p = 0.002), there was no significant association with IL-6 (n = 48) or total HIV-1 DNA (n = 51). Conclusions: Using plasma NfL as a surrogate marker, a decrease in neuro-axonal injury was observed in a cohort of participants following ART initiation during PHI, with no evidence of neuro-axonal injury rebound following ART interruption for up to 12 weeks, despite viral rebound in the majority of participants.
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- Bernardino, Jose I, et al.
(author)
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Bone mineral density and inflammatory and bone biomarkers after darunavir-ritonavir combined with either raltegravir or tenofovir-emtricitabine in antiretroviral-naive adults with HIV-1 : a substudy of the NEAT001/ANRS143 randomised trial
- 2015
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In: The Lancet. - 1474-547X .- 2352-3018. ; 2:11, s. 73-464
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Journal article (peer-reviewed)abstract
- BACKGROUND: Osteopenia, osteoporosis, and low bone mineral density are frequent in patients with HIV. We assessed the 96 week loss of bone mineral density associated with a nucleoside or nucleotide reverse transcriptase inhibitor (NtRTI)-sparing regimen.METHODS: Antiretroviral-naive adults with HIV were enrolled in 78 clinical sites in 15 European countries into a randomised (1:1), open-label, non-inferiority trial (NEAT001/ANRS143) assessing the efficacy and safety of darunavir (800 mg once per day) and ritonavir (100 mg once per day) plus either raltegravir (400 mg twice per day; NtRTI-sparing regimen) or tenofovir (245 mg once per day) and emtricitabine (200 mg once per day; standard regimen). For this bone-health substudy, 20 of the original sites in six countries participated, and any patient enrolled at one of these sites who met the following criteria was eligible: plasma viral loads greater than 1000 HIV RNA copies per mL and CD4 cell counts of fewer than 500 cells per μL, except in those with symptomatic HIV infection. Exclusion criteria included treatment for malignant disease, testing positive for hepatitis B virus surface antigen, pregnancy, creatinine clearance less than 60 mL per min, treatment for osteoporosis, systemic steroids, or oestrogen-replacement therapy. The two primary endpoints were the mean percentage changes in lumbar spine and total hip bone mineral density at week 48, assessed by dual energy x-ray absorptiometry (DXA) scans. We did the analysis with an intention-to-treat-exposed approach with antiretroviral modifications ignored. The parent trial is registered with ClinicalTrials.gov, number NCT01066962, and is closed to new participants.FINDINGS: Between Aug 2, 2010, and April 18, 2011, we recruited 146 patients to the substudy, 70 assigned to the NtRTI-sparing regimen and 76 to the standard regimen. DXA data were available for 129, 121 and 107 patients at baseline, 48 and 96 weeks respectively. At week 48, the mean percentage loss in bone mineral density in the lumbar spine was greater in the standard group than in the NtRTI-sparing group (mean percentage change -2.49% vs -1.00%, mean percentage difference -1.49, 95% CI -2.94 to -0.04; p=0.046). Total hip bone mineral density loss was similarly greater at week 48 in the standard group than in the NtRTI-sparing group (mean percentage change -3.30% vs -0.73%; mean percentage difference -2.57, 95% CI -3.75 to -1.35; p<0.0001). Seven new fractures occurred during the trial (two in the NtRTI-sparing group and five in the standard group).INTERPRETATION: A raltegravir-based regimen was associated with significantly less loss of bone mineral density than a standard regimen containing tenofovir disoproxil fumarate, and might be a treatment option for patients at high risk of osteopenia or osteoporosis who are not suitable for NtRTIs such as abacavir or tenofovir alafenamide.FUNDING: The European Union Sixth Framework Programme, Inserm-ANRS, Ministerio de Sanidad y Asuntos Sociales de España, Gilead Sciences, Janssen Pharmaceuticals, and Merck Laboratories.
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- Lambert-Niclot, S., et al.
(author)
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Antiretroviral resistance at virological failure in the NEAT 001/ANRS 143 trial: Raltegravir plus darunavir/ritonavir or tenofovir/emtricitabine plus darunavir/ritonavir as first-line ART
- 2016
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In: Journal of Antimicrobial Chemotherapy. - : Oxford University Press (OUP). - 1460-2091 .- 0305-7453. ; 71:4, s. 1056-1062
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Journal article (peer-reviewed)abstract
- Objectives: To describe the pattern of drug resistance at virological failure in the NEAT001/ANRS143 trial (first-line treatment with ritonavir-boosted darunavir plus either tenofovir/emtricitabine or raltegravir). Methods: Genotypic testing was performed at baseline for reverse transcriptase (RT) and protease genes and for RT, protease and integrase (IN) genes for patients with a confirmed viral load (VL) >50 copies/mL or any single VL >500 copies/mL during or after week 32. Results: A resistance test was obtained for 110/805 (13.7%) randomized participants qualifying for resistance analysis (61/401 of participants in the raltegravir arm and 49/404 of participants in the tenofovir/emtricitabine arm). No resistance-associated mutation (RAM) was observed in the tenofovir/emtricitabine plus darunavir/ritonavir arm, and all further analyses were limited to the raltegravir plus darunavir arm. In this group, 15/55 (27.3%) participants had viruses with IN RAMs (12 N155H alone, 1 N155H + Q148R, 1 F121Y and 1 Y143C), 2/53 (3.8%) with nucleotide analogue RT inhibitor RAMs (K65R, M41L) and 1/57 (1.8%) with primary protease RAM (L76V). The frequency of IN mutations at failure was significantly associated with baseline VL: 7.1% for a VL of TREND = 0.007). Of note, 4/15 participants with IN RAM had a VL <200 copies/mL at time of testing. Conclusions: In the NEAT001/ANRS143 trial, there was no RAM at virological failure in the standard tenofovir/emtricitabine plus darunavir/ritonavir regimen, contrasting with a rate of 29.5% (mostly IN mutations) in the raltegravir plus darunavir/ritonavir NRTI-sparing regimen. The cumulative risk of IN RAM after 96 weeks of follow-up in participants initiating ART with raltegravir plus darunavir/ritonavir was 3.9%.
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- Lundgren, Jens D, et al.
(author)
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Long-Term Benefits from Early Antiretroviral Therapy Initiation in HIV Infection.
- 2023
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In: NEJM evidence. - : Massachusetts Medical Society. - 2766-5526. ; 2:3
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Journal article (peer-reviewed)abstract
- For people with HIV and CD4+ counts >500 cells/mm3, early initiation of antiretroviral therapy (ART) reduces serious AIDS and serious non-AIDS (SNA) risk compared with deferral of treatment until CD4+ counts are <350 cells/mm3. Whether excess risk of AIDS and SNA persists once ART is initiated for those who defer treatment is uncertain.The Strategic Timing of AntiRetroviral Treatment (START) trial, as previously reported, randomly assigned 4684 ART-naive HIV-positive adults with CD4+ counts .500 cells/mm3 to immediate treatment initiation after random assignment (n = 2325) or deferred treatment (n= 2359). In 2015, a 57% lower risk of the primary end point (AIDS, SNA, or death) for the immediate group was reported, and the deferred group was offered ART. This article reports the follow-up that continued to December 31, 2021. Cox proportional-hazards models were used to compare hazard ratios for the primary end point from randomization through December 31, 2015, versus January 1, 2016, through December 31, 2021.Through December 31, 2015, approximately 7 months after the cutoff date from the previous report, the median CD4+ count was 648 and 460 cells/mm3 in the immediate and deferred groups, respectively, at treatment initiation. The percentage of follow-up time spent taking ART was 95% and 36% for the immediate and deferred groups, respectively, and the time-averaged CD4+ difference was 199 cells/mm3. After January 1, 2016, the percentage of follow-up time on treatment was 97.2% and 94.1% for the immediate and deferred groups, respectively, and the CD4+ count difference was 155 cells/mm3. After January 1, 2016, a total of 89 immediate and 113 deferred group participants experienced a primary end point (hazard ratio of 0.79 [95% confidence interval, 0.60 to 1.04] versus hazard ratio of 0.47 [95% confidence interval, 0.34 to 0.65; P<0.001]) before 2016 (P=0.02 for hazard ratio difference).Among adults with CD4+ counts >500 cells/mm3, excess risk of AIDS and SNA associated with delaying treatment initiation was diminished after ART initiation, but persistent excess risk remained. (Funded by the National Institute of Allergy and Infectious Diseases and others.).
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- Raffi, François, et al.
(author)
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Ritonavir-boosted darunavir combined with raltegravir or tenofovir-emtricitabine in antiretroviral-naive adults infected with HIV-1 : 96 week results from the NEAT001/ANRS143 randomised non-inferiority trial
- 2014
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In: The Lancet. - 1474-547X. ; 384:9958, s. 51-1942
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Journal article (peer-reviewed)abstract
- BACKGROUND: Standard first-line antiretroviral therapy for HIV-1 infection includes two nucleoside or nucleotide reverse transcriptase inhibitors (NtRTIs), but these drugs have limitations. We assessed the 96 week efficacy and safety of an NtRTI-sparing regimen.METHODS: Between August, 2010, and September, 2011, we enrolled treatment-naive adults into this randomised, open-label, non-inferiority trial in treatment-naive adults in 15 European countries. The composite primary outcome was change to randomised treatment before week 32 because of insufficient virological response, no virological response by week 32, HIV-1 RNA concentration 50 copies per mL or higher at any time after week 32; death from any cause; any new or recurrent AIDS event; or any serious non-AIDS event. Patients were randomised in a 1:1 ratio to receive oral treatment with 400 mg raltegravir twice daily plus 800 mg darunavir and 100 mg ritonavir once daily (NtRTI-sparing regimen) or tenofovir-emtricitabine in a 245 mg and 200 mg fixed-dose combination once daily, plus 800 mg darunavir and 100 mg ritonavir once daily (standard regimen). This trial was registered with ClinicalTrials.gov, number NCT01066962.FINDINGS: Of 805 patients enrolled, 401 received the NtRTI-sparing regimen and 404 the standard regimen, with median follow-up of 123 weeks (IQR 112-133). Treatment failure was seen in 77 (19%) in the NtRTI-sparing group and 61 (15%) in the standard group. Kaplan-Meier estimated proportions of treatment failure by week 96 were 17·8% and 13·8%, respectively (difference 4·0%, 95% CI -0·8 to 8·8). The frequency of serious or treatment-modifying adverse events were similar (10·2 vs 8·3 per 100 person-years and 3·9 vs 4·2 per 100 person-years, respectively).INTERPRETATION: Our NtRTI-sparing regimen was non-inferior to standard treatment and represents a treatment option for patients with CD4 cell counts higher than 200 cells per μL.FUNDING: European Union Sixth Framework Programme, Inserm-ANRS, Gilead Sciences, Janssen Pharmaceuticals, Merck Laboratories.
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