Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Jonathan B. Angel is active.

Publication


Featured researches published by Jonathan B. Angel.


PLOS ONE | 2009

Fertility desires and intentions of HIV-positive women of reproductive age in Ontario, Canada: a cross-sectional study.

Mona Loutfy; Trevor A. Hart; Saira Mohammed; DeSheng Su; Sharon Walmsley; Lena Soje; Marvelous Muchenje; Anita Rachlis; Fiona Smaill; Jonathan B. Angel; Janet Raboud; Michael S. Silverman; Wangari Tharao; Kevin Gough; Mark H. Yudin

Background Improvements in life expectancy and quality of life for HIV-positive women coupled with reduced vertical transmission will likely lead numerous HIV-positive women to consider becoming pregnant. In order to clarify the demand, and aid with appropriate health services planning for this population, our study aims to assess the fertility desires and intentions of HIV-positive women of reproductive age living in Ontario, Canada. Methodology/Principal Findings A cross-sectional study with recruitment stratified to match the geographic distribution of HIV-positive women of reproductive age (18–52) living in Ontario was carried out. Women were recruited from 38 sites between October 2007 and April 2009 and invited to complete a 189-item self-administered survey entitled “The HIV Pregnancy Planning Questionnaire” designed to assess fertility desires, intentions and actions. Logistic regression models were fit to calculate unadjusted and adjusted odds ratios of significant predictors of fertility intentions. The median age of the 490 participating HIV-positive women was 38 (IQR, 32–43) and 61%, 52%, 47% and 74% were born outside of Canada, living in Toronto, of African ethnicity and currently on antiretroviral therapy, respectively. Of total respondents, 69% (95% CI, 64%–73%) desired to give birth and 57% (95% CI, 53%–62%) intended to give birth in the future. In the multivariable model, the significant predictors of fertility intentions were: younger age (age<40) (p<0.0001), African ethnicity (p<0.0001), living in Toronto (pu200a=u200a0.002), and a lower number of lifetime births (pu200a=u200a0.02). Conclusions/Significance The proportions of HIV-positive women of reproductive age living in Ontario desiring and intending pregnancy were higher than reported in earlier North American studies. Proportions were more similar to those reported from African populations. Healthcare providers and policy makers need to consider increasing services and support for pregnancy planning for HIV-positive women. This may be particularly significant in jurisdictions with high levels of African immigration.


The Lancet | 2017

Long-acting intramuscular cabotegravir and rilpivirine in adults with HIV-1 infection (LATTE-2): 96-week results of a randomised, open-label, phase 2b, non-inferiority trial

David A. Margolis; Juan González-García; Hans Jürgen Stellbrink; Joseph J. Eron; Yazdan Yazdanpanah; Daniel Podzamczer; Thomas A. Lutz; Jonathan B. Angel; Gary Richmond; Bonaventura Clotet; Félix Gutiérrez; Louis Sloan; Marty St. Clair; Miranda Murray; Susan L. Ford; Joseph Mrus; Parul Patel; Herta Crauwels; Sandy Griffith; Kenneth C. Sutton; David Dorey; Kimberly Y. Smith; Peter Williams; William Spreen

BACKGROUNDnCabotegravir and rilpivirine are antiretroviral drugs in development as long-acting injectable formulations. The LATTE-2 study evaluated long-acting cabotegravir plus rilpivirine for maintenance of HIV-1 viral suppression through 96 weeks.nnnMETHODSnIn this randomised, phase 2b, open-label study, treatment-naive adults infected with HIV-1 initially received oral cabotegravir 30 mg plus abacavir-lamivudine 600-300 mg once daily. The objective of this study was to select an intramuscular dosing regimen based on a comparison of the antiviral activity, tolerability, and safety of the two intramuscular dosing regimens relative to oral cabotegravir plus abacavir-lamivudine. After a 20-week induction period on oral cabotegravir plus abacavir-lamivudine, patients with viral suppression (plasma HIV-1 RNA <50 copies per mL) were randomly assigned (2:2:1) to intramuscular long-acting cabotegravir plus rilpivirine at 4-week intervals (long-acting cabotegravir 400 mg plus rilpivirine 600 mg; two 2 mL injections) or 8-week intervals (long-acting cabotegravir 600 mg plus rilpivirine 900 mg; two 3 mL injections) or continued oral cabotegravir plus abacavir-lamivudine. Randomisation was computer-generated with stratification by HIV-1 RNA (<50 copies per mL, yes or no) during the first 12 weeks of the induction period. The primary endpoints were the proportion of patients with viral suppression at week 32 (as defined by the US Food and Drug Administration snapshot algorithm), protocol-defined virological failures, and safety events through 96 weeks. All randomly assigned patients who received at least one dose of study drug during the maintenance period were included in the primary efficacy and safety analyses. The primary analysis used a Bayesian approach to evaluate the hypothesis that the proportion with viral suppression for each long-acting regimen is not worse than the oral regimen proportion by more than 10% (denoted comparable) according to a prespecified decision rule (ie, posterior probability for comparability >90%). Difference in proportions and associated 95% CIs were supportive to the primary analysis. The trial is registered at ClinicalTrials.gov, number NCT02120352.nnnFINDINGSnAmong 309 enrolled patients, 286 were randomly assigned to the maintenance period (115 to each of the 4-week and 8-week groups and 56 to the oral treatment group). This study is currently ongoing. At 32 weeks following randomisation, both long-acting regimens met primary criteria for comparability in viral suppression relative to the oral comparator group. Viral suppression was maintained at 32 weeks in 51 (91%) of 56 patients in the oral treatment group, 108 (94%) of 115 patients in the 4-week group (difference 2·8% [95% CI -5·8 to 11·5] vs oral treatment), and 109 (95%) of 115 patients in the 8-week group (difference 3·7% [-4·8 to 12·2] vs oral treatment). At week 96, viral suppression was maintained in 47 (84%) of 56 patients receiving oral treatment, 100 (87%) of 115 patients in the 4-week group, and 108 (94%) of 115 patients in the 8-week group. Three patients (1%) experienced protocol-defined virological failure (two in the 8-week group; one in the oral treatment group). Injection-site reactions were mild (3648 [84%] of 4360 injections) or moderate (673 [15%] of 4360 injections) in intensity and rarely resulted in discontinuation (two [<1%] of 230 patients); injection-site pain was reported most frequently. Serious adverse events during maintenance were reported in 22 (10%) of 230 patients in the intramuscular groups (4-week and 8-week groups) and seven (13%) of 56 patients in the oral treatment group; none were drug related.nnnINTERPRETATIONnThe two-drug combination of all-injectable, long-acting cabotegravir plus rilpivirine every 4 weeks or every 8 weeks was as effective as daily three-drug oral therapy at maintaining HIV-1 viral suppression through 96 weeks and was well accepted and tolerated.nnnFUNDINGnViiV Healthcare and Janssen R&D.


PLOS ONE | 2011

Discontinuation of Pneumocystis jirovecii Pneumonia Prophylaxis with CD4 Count <200 Cells/µL and Virologic Suppression: A Systematic Review

Cecilia T. Costiniuk; Dean Fergusson; Steve Doucette; Jonathan B. Angel

Background HIV viral load (VL) is currently not part of the criteria for Pneumocystis jirovecii pneumonia (PCP) prophylaxis discontinuation, but suppression of plasma viremia with antiretroviral therapy may allow for discontinuation of PCP prophylaxis even with CD4 count <200 cells/µL. Methods A systematic review was performed to determine the incidence of PCP in HIV-infected individuals with CD4 count <200 cells/µL and fully suppressed VL on antiretroviral therapy but not receiving PCP prophylaxis. Results Four articles examined individuals who discontinued PCP prophylaxis with CD4 count <200 cells/µL in the context of fully suppressed VL on antiretroviral therapy. The overall incidence of PCP was 0.48 cases per 100 person-years (PY) (95% confidence interval (CI) (0.06–0.89). This was lower than the incidence of PCP in untreated HIV infection (5.30 cases/100 PY, 95% CI 4.1–6.8) and lower than the incidence in persons with CD4 count <200 cells/µL, before the availability of highly active antiretroviral therapy (HAART), who continued prophylaxis (4.85/100 PY, 95% CI 0.92–8.78). In one study in which individuals were stratified according to CD4 count <200 cells/µL, there was a greater risk of PCP with CD4 count ≤100 cells/µL compared to 101–200 cells/µL. Conclusion Primary PCP prophylaxis may be safely discontinued in HIV-infected individuals with CD4 count between 101–200 cells/µL provided the VL is fully suppressed on antiretroviral therapy. However, there are inadequate data available to make this recommendation when the CD4 count is ≤100 cells/µL. A revision of guidelines on primary PCP prophylaxis to include consideration of the VL is merited.


Aids Care-psychological and Socio-medical Aspects of Aids\/hiv | 2014

The importance of motherhood in HIV-positive women of reproductive age in Ontario, Canada

V. Logan Kennedy; Lena Serghides; Janet Raboud; DeSheng Su; Sandra Blitz; Trevor A. Hart; Sharon Walmsley; Jonathan B. Angel; Fiona Smaill; Wangari Tharao; Mona Loutfy

Motherhood is personally, culturally, and historically rooted. Recent publications have focused on medical issues related to pregnancy and HIV, with attention on fetal well-being. There is limited literature on the importance of motherhood for HIV-positive women. Our studys purpose was to investigate the importance of motherhood among HIV-positive women of reproductive age in Ontario, Canada and to analyze the correlates thereof. We present our findings using a secondary analysis of cross-sectionally collected data from a study assessing fertility desires and intentions of HIV-positive women. The sub-analysiss outcome of interest was based on the question: “Being a mother is important to me” with a 5-point Likert scale that was dichotomized into strongly agree/agree vs. neutral/disagree/strongly disagree. Logistic regression models were fit to calculate unadjusted and adjusted odds ratios (ORs) for significant correlates. Of the 497 respondents, median age was 38 (interquartile range [IQR] 32–43), 46% were African, 74% had given birth, and 57% intended to give birth. A total of 452 (91%) agreed (N = 75) or strongly agreed (N = 377) that being a mother was important to them. Age less than 40 years (OR 3.0; 95% confidence interval [CI] 1.6–5.7, African ethnicity (OR 9.2; 95% CI 3.2–26.3), immigration within 10 years (OR 19.6, 95% CI 4.6–83.1), and partner or family desire for a pregnancy (OR 3.3; 95% CI 1.5–7.3) were significant correlates of the importance of motherhood in a univariate analysis. Importance of motherhood was associated with desire (OR 6.2, 95% CI 3.1–12.3) and intention to give birth (OR 6.9, 95% CI 3.1–15.2), and previous birth (OR 8.5, 95% CI 4.2–16.8). In the multivariable model, the significant correlates were of age less than 40 years (OR 3.9; 95% CI 1.8–8.4), immigration within 10 years (OR 14.1; 95% CI 3.2–61.5), and having previously given birth (OR 11.2; 95% CI 5.1–24.4). The majority of women felt strongly that motherhood was important to them particularly among younger women, recent immigrants, and women who were mothers.


The Journal of Infectious Diseases | 2012

Circulating Endothelial Progenitor Cell Levels Are Not Reduced in HIV-Infected Men

Cecilia T. Costiniuk; Benjamin Hibbert; Lionel G. Filion; Colin Kovacs; Erika Benko; Edward R. O’Brien; Jonathan B. Angel

Reduced levels of endothelial progenitor cells (EPCs) have been associated with increased cardiovascular (CV) risk, but limited data are available on EPC levels in the human immunodeficiency virus (HIV)-infected population. EPCs (CD45(dim)/CD34(+)/kinase domain receptor(+)) from 36 HIV-uninfected and 30 antiretroviral therapy-naive HIV-infected men without known CV risk factors were enumerated using flow cytometry. The mean EPC levels (± standard error of the mean) were 1.4 ± 0.5 cells/μL in the HIV-infected group and 3.7 ± 2.2 cells/μL in the control group (P = .92). EPC levels were not associated with disease parameters, such as CD4 cell count or viral load. Reductions in EPC levels do not seem to explain the increased risk of CV disease among HIV-infected men.


PLOS Pathogens | 2010

Patients with discordant responses to antiretroviral therapy have impaired killing of HIV-infected T cells.

Sekar Natesampillai; Zilin Nie; Nathan W. Cummins; Dirk Jochmans; Gary D. Bren; Jonathan B. Angel; Andrew D. Badley

In medicine, understanding the pathophysiologic basis of exceptional circumstances has led to an enhanced understanding of biology. We have studied the circumstance of HIV-infected patients in whom antiretroviral therapy results in immunologic benefit, despite virologic failure. In such patients, two protease mutations, I54V and V82A, occur more frequently. Expressing HIV protease containing these mutations resulted in less cell death, caspase activation, and nuclear fragmentation than wild type (WT) HIV protease or HIV protease containing other mutations. The impaired induction of cell death was also associated with impaired cleavage of procaspase 8, a requisite event for HIV protease mediated cell death. Primary CD4 T cells expressing I54V or V82A protease underwent less cell death than with WT or other mutant proteases. Human T cells infected with HIV containing these mutations underwent less cell death and less Casp8p41 production than WT or HIV containing other protease mutations, despite similar degrees of viral replication. The reductions in cell death occurred both within infected cells, as well as in uninfected bystander cells. These data indicate that single point mutations within HIV protease which are selected in vivo can significantly impact the ability of HIV to kill CD4 T cells, while not impacting viral replication. Therefore, HIV protease regulates both HIV replication as well as HIV induced T cell depletion, the hallmark of HIV pathogenesis.


Journal of the International Association of Providers of AIDS Care | 2014

Self-Reported Preconception Care of HIV-Positive Women of Reproductive Potential: A Retrospective Study

Mona Loutfy; Sandra Blitz; Yimeng Zhang; Trevor A. Hart; Sharon Walmsley; Fiona Smaill; Anita Rachlis; Mark H. Yudin; Jonathan B. Angel; Wangari Tharao; Janet Raboud

Objectives: We determined the proportion and correlates of self-reported pregnancy planning discussions (that is preconception counseling) that HIV-positive women reported to their family physicians (FPs), HIV specialists, and obstetrician/gynecologists (OB/Gyns). Methods: In a cross-sectional substudy, HIV-positive women of reproductive potential were asked whether their care providers discussed pregnancy planning. Logistic regression was used to calculate odds ratios for the correlates of preconception counseling. Results: A total of 431 eligible participants (median age 38, interquartile range = 32-43) reported having discussion with a physician (92% FP, 96% HIV specialists, and 45% OB/Gyns). In all, 34%, 41%, and 38% had their pregnancy planning discussion with FP, HIV specialist, and Ob/Gyns, respectively; 51% overall. In the multivariable model, significant correlates of preconception counseling were age (P = .02), marital status (P < .01), number of years living in Canada (P < .001), and age of youngest child (P < .01). Conclusions: Preconception care in our cohort was suboptimal. We recommend that counseling on healthy preconception should be part of routine HIV care.


Journal of Immigrant and Minority Health | 2012

HIV knowledge among Canadian-born and sub-Saharan African-born patients living with HIV.

Heather Tulloch; Louise Balfour; John Kowal; Georgio A. Tasca; Jonathan B. Angel; Gary Garber; Paul MacPherson; Curtis Cooper; D. W. Cameron

Research has revealed differences on scales measuring HIV knowledge between individuals from various ethnic backgrounds and cultures. Few studies have examined this knowledge with immigrant populations and persons living with HIV. This study examined HIV knowledge among persons living with HIV who were either born in Canada or in sub-Saharan Africa and, for comparison, in a sample of college students. All participants were residing in Canada. Participants completed questionnaires measuring demographic variables, sexual health behaviour, and HIV status, treatment, and knowledge. Canadian-born patients living with HIV were more likely to be older and male than the other groups. On average, patients living with HIV were diagnosed 6.4xa0years ago, and 80% reported having current or previous experience taking HIV medications. After adjusting for age and gender, significant differences were found between the groups on the Brief HIV Knowledge Questionnaire. Canadian-born persons living with HIV (nxa0=xa0110) scored higher than sub-Saharan African-born patients (nxa0=xa023) and college students (nxa0=xa081); mean percentage correct was 86, 70, and 62%, respectively (Pxa0<xa0.01). These results suggested that ongoing HIV education is needed for all groups, and that additional tailored and targeted educational interventions are needed to address important gaps in knowledge among persons living with HIV patients originating from Africa and among college students.


Clinical Infectious Diseases | 2001

Effect of Cessation of Highly Active Antiretroviral Therapy during a Discordant Response: Implications for Scheduled Therapeutic Interruptions

Nanci Hawley-Foss; Georgina Mbisa; Julian J. Lum; André A. Pilon; Jonathan B. Angel; Gary Garber; Andrew D. Badley

Although treatment with combination antiretroviral therapy leads to a reduction in the level of plasma viremia and an improvement in CD4 T cell count for most patients, for a minority of patients, an improvement in CD4 T cell count occurs despite the failure of treatment to suppress viral replication. Recent reports suggest that these discordant improvements in CD4 T cell count may last for months to years and are associated with improved clinical outcomes. In a retrospective observational study, we evaluated the effect of therapy cessation on 8 patients with discordant immunologic responses to therapy and found that improved CD4 T cell responses are dependent upon ongoing drug pressure. If antiretroviral agents that are likely to resuppress the virus are not available, we suggest that patients continue the therapy associated with immunologic improvement to maximize the clinical benefit of the discordant response.


Canadian Journal of Infectious Diseases & Medical Microbiology | 2001

Characteristics of Hepatitis C Virus Infection in HIV-Infected People

Curtis Cooper; Andrew D. Badley; Jonathan B. Angel

Knowledge pertaining to hepatitis C virus (HCV)/human immunodeficiency virus (HIV) co-infection is currently incomplete or conflicting. Several points are well studied, however. Plasma HCV RNA levels are higher in matched HIV-infected people than in HIV-seronegative control subjects and are inversely correlated with CD4(+) T lymphocyte counts. HCV genotype does not appear to influence this value. Co-infected individuals develop histological and clinical features of HCV liver disease more rapidly than HIV-seronegative patients. Co-infected individuals appear to respond to interferon-alpha therapy equally as well as HIV-seronegative HCV-infected adults, but minimal information exists regarding the efficacy and toxicity of combination HCV therapy (interferon-alpha plus ribavirin) in this population. Adverse consequences of highly active antiretroviral therapy in co-infected patients include hepatic toxicity and, in a minority of patients, an immune restoration syndrome. It is unclear whether long term, highly active antiretroviral therapy positively or negatively influences the natural history of HCV infection.

Collaboration


Dive into the Jonathan B. Angel's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Sharon Walmsley

University Health Network

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge