Identification of SARS-CoV-2 biomarkers in saliva by transcriptomic and proteomics analysis.

The detection of SARS-CoV-2 biomarkers by real time PCR (rRT-PCR) has shown that the sensitivity of the test is negatively affected by low viral loads and the severity of the disease. This limitation can be overcome by the use of more sensitive approaches such as mass spectrometry (MS), which has not been explored for the detection of SARS-CoV-2 proteins in saliva. Thus, this study aimed at assessing the translational applicability of mass spectrometry-based proteomics approaches to identify viral proteins in saliva from people diagnosed with COVID-19 within fourteen days after the initial diagnosis, and to compare its performance with rRT-PCR. After ethics approval, saliva samples were self-collected by 42 COVID-19 positive and 16 healthy individuals. Samples from people positive for COVID-19 were collected on average on the sixth day (± 4 days) after initial diagnosis. Viable viral particles in saliva were heat-inactivated followed by the extraction of total proteins and viral RNA. Proteins were digested and then subjected to tandem MS analysis (LC-QTOF-MS/MS) using a data-dependent MS/MS acquisition qualitative shotgun proteomics approach. The acquired spectra were queried against a combined SARS-CoV-2 and human database. The qualitative detection of SARS-CoV-2 specific RNA was done by rRT-PCR. SARS-CoV-2 proteins were identified in all COVID-19 samples (100%), while viral RNA was detected in only 24 out of 42 COVID-19 samples (57.1%). Seven out of 18 SARS-CoV-2 proteins were identified in saliva from COVID-19 positive individuals, from which the most frequent were replicase polyproteins 1ab (100%) and 1a (91.3%), and nucleocapsid (45.2%). Neither viral proteins nor RNA were detected in healthy individuals. Our mass spectrometry approach appears to be more sensitive than rRT-PCR for the detection of SARS-CoV-2 biomarkers in saliva collected from COVID-19 positive individuals up to 14 days after the initial diagnostic test. Based on the novel data presented here, our MS technology can be used as an effective diagnostic test of COVID-19 for initial diagnosis or follow-up of symptomatic cases, especially in patients with reduced viral load.

Characteristics and outcomes of antiretroviral-treated HIV-HBV co-infected patients in Canada?

BACKGROUND: Hepatitis B (HBV) and Human Immunodeficiency Virus (HIV) share common risk factors for exposure. Co-infected patients have an increased liver-related mortality risk and may have accelerated HIV progression. The epidemiology and demographic characteristics of HIV-HBV co-infection in Canada remain poorly defined. We compared the demographic and clinical characteristics and factors associated with advanced hepatic fibrosis between HIV and HIV-HBV co-infected patients. METHODS: A retrospective cohort analysis was conducted using data from the Canadian Observational Cohort (CANOC) Collaboration, including eight sites from British Columbia, Quebec, and Ontario. Eligible participants were HIV-infected patients who initiated combination ARV between January 1, 2000 and December 14, 2014. Demographic and clinical characteristics were compared between HIV-HBV co-infected and HIV-infected groups using chi-square or Fisher exact tests for categorical variables, and Wilcoxon's Rank Sum test for continuous variables. Liver fibrosis was estimated by the AST to Platelet Ratio Index (APRI). RESULTS: HBV status and APRI values were available for 2419 cohort participants. 199 (8%) were HBV co-infected. Compared to HIV-infected participants, HIV-HBV co-infected participants were more likely to use injection drugs (28% vs. 21%, p = 0.03) and be HCV-positive (31%, vs. 23%, p = 0.02). HIV-HBV co-infected participants had lower baseline CD4 T cell counts (188 cells/mm3, IQR: 120-360) compared to 235 cells/mm3 in HIV-infected participants (IQR: 85-294) (p = 0.0002) and higher baseline median APRI scores (0.50 vs. 0.37, p < 0.0001). This difference in APRI was no longer clinically significant at follow-up (0.32 vs. 0.30, p = 0.03). HIV-HBV co-infected participants had a higher mortality rate compared to HIV-infected participants (11% vs. 7%, p = 0.02). CONCLUSION: The prevalence, demographic and clinical characteristics of the HIV-HBV co-infected population in Canada is described. HIV-HBV co-infected patients have higher mortality, more advanced CD4 T cell depletion, and liver fibrosis that improves in conjunction with ARV therapy. The high prevalence of unknown HBV status demonstrates a need for increased screening among HIV-infected patients in Canada.

Emergomyces canadensis, a Dimorphic Fungus Causing Fatal Systemic Human Disease in North America.

We report 4 patients in North America with disease caused by Emergomyces canadensis, a newly proposed species of pathogenic dimorphic fungus. Affected persons were immunocompromised; lived in Saskatchewan, Colorado, and New Mexico; and had systemic disease involving blood, skin, cervix, lung, and lymph node. Two cases were fatal.

Pediatric intracranial tuberculoma: illustrative case.

BACKGROUND: Tuberculosis is an airborne disease caused by Mycobacterium tuberculosis. Intracranial tuberculoma is a rare complication of extrapulmonary tuberculosis due to hematogenous spread to subpial and subependymal regions. Intracranial tuberculoma can occur with or without meningitis. OBSERVATIONS: A 3-year-old male who had recently emigrated from Sudan presented to the emergency department with right-sided seizures lasting 30 minutes, which were aborted with levetiracetam and midazolam. Head computed tomography revealed a multilobulated left supratentorial mass with solid and cystic components and measuring 8.0 × 4.8 × 6.5 cm. The patient had successful resection of the mass, which was positive for M. tuberculosis. He was started on rifampin, isoniazid, pyrazinamide, ethambutol, and fluoroquinolone and was discharged home in stable condition. LESSONS: A literature review on pediatric intracranial tuberculoma was performed, which included 48 studies (n = 49). The mean age was 8.8 ± 5.4 years with a slight female predilection (59%). Predominant solitary tuberculomas (63%) were preferentially managed with both resection and antituberculosis therapy (ATT), whereas multifocal tuberculomas were preferentially managed with ATT. Intracranial tuberculoma is a rare but treatable cause of space-occupying lesions in children. Clinicians should maintain a high level of suspicion in patients from endemic regions and involve the infectious disease service early.

Characterizing the HIV epidemic in the prairie provinces.

BACKGROUND: The numbers and demographics of HIV-positive patients in care between 2003 and 2007 in the prairie provinces were examined. METHODS: Estimates of HIV-positive patients presenting to care between 2003 and 2007 were obtained from four clinic registries in Manitoba, Saskatchewan and southern Alberta. Detailed data were collected from clinical records of new patients in 2007. RESULTS: By the end of December 2007, 2263 HIV-positive persons were in care in Manitoba, Saskatchewan and southern Alberta. Males and females accounted for 1674 (74.0%) and 589 of the cases, respectively. Overall, there was a 12% increase per year in new HIV cases to care between 2003 and 2007 (P=0.026), with the rate of increase for males being 60% higher than for females over this time period (P=0.002). In 2007, there were 222 new HIV cases to care (37.4% female). Heterosexual contact was the most common HIV risk, but diversity was seen across sites with frequent injection drug use and men who have sex with men risk in Saskatchewan and southern Alberta, respectively. The Aboriginal population remains heavily over-represented, with approximately 36.0% of new cases being Aboriginal. Late presentation was common across all care sites, with 35.1% of cases presenting with CD4 counts of less than 200 cells/mm(3). DISCUSSION: Heterosexual risk is the most common risk reported for HIV acquisition, but injection drug use risk remains significant in Saskatchewan. Aboriginals are over-represented at all sites, and in Saskatchewan accounted for the majority of new cases seen. In contrast to national trends, numbers of new and late diagnoses are increasing in the praire provinces, and this has significant treatment implications and potential public health consequences. Further efforts need to be made to facilitate earlier testing and linkage to care. BACKGROUND: The numbers and demographics of HIV-positive patients in care between 2003 and 2007 in the prairie provinces were examined. METHODS: Estimates of HIV-positive patients presenting to care between 2003 and 2007 were obtained from four clinic registries in Manitoba, Saskatchewan and southern Alberta. Detailed data were collected from clinical records of new patients in 2007. RESULTS: By the end of December 2007, 2263 HIV-positive persons were in care in Manitoba, Saskatchewan and southern Alberta. Males and females accounted for 1674 (74.0%) and 589 of the cases, respectively. Overall, there was a 12% increase per year in new HIV cases to care between 2003 and 2007 (P=0.026), with the rate of increase for males being 60% higher than for females over this time period (P=0.002). In 2007, there were 222 new HIV cases to care (37.4% female). Heterosexual contact was the most common HIV risk, but diversity was seen across sites with frequent injection drug use and men who have sex with men risk in Saskatchewan and southern Alberta, respectively. The Aboriginal population remains heavily over-represented, with approximately 36.0% of new cases being Aboriginal. Late presentation was common across all care sites, with 35.1% of cases presenting with CD4 counts of less than 200 cells/mm3. DISCUSSION: Heterosexual risk is the most common risk reported for HIV acquisition, but injection drug use risk remains significant in Saskatchewan. Aboriginals are over-represented at all sites, and in Saskatchewan accounted for the majority of new cases seen. In contrast to national trends, numbers of new and late diagnoses are increasing in the praire provinces, and this has significant treatment implications and potential public health consequences. Further efforts need to be made to facilitate earlier testing and linkage to care.

HISTORIQUE: Les chercheurs ont examiné le nombre et la démographie des patients positifs au VIH soignés entre 2003 et 2007 dans les provinces des Prairies. MÉTHODOLOGIE: Les chercheurs ont pu évaluer le nombre de patients positifs au VIH qui ont consulté pour la première fois entre 2003 et 2007 d'après quatre registres cliniques du Manitoba, de la Saskatchewan et du sud de l'Alberta. Ils ont également recueilli les données détaillées des dossiers cliniques de nouveaux patients en 2007. RÉSULTATS: À la fin de décembre 2007, 2 263 personnes positives au VIH étaient soignées au Manitoba, en Saskatchewan et dans le sud de l'Alberta. Les hommes et les femmes représentaient 1 674 (74,0 %) et 589 cas, respectivement. Dans l'ensemble, on a constaté une augmentation annuelle de 12 % des nouveaux cas de VIH soignés entre 2003 et 2007 (P=0,026), le taux d'augmentation pour les hommes étant 60 % plus élevé que pour les femmes (P=0,002). En 2007, on a recensé 222 nouveaux cas de VIH soignés (37,4 % de femmes). Le contact hétérosexuel représentait le principal risque de VIH, mais on remarquait une diversité selon les lieux, le risque posé par la consommation fréquente de drogues par injection et par les relations sexuelles entre hommes étant observé en Saskatchewan et au sud de l'Alberta, respectivement. La population autochtone demeure lourdement surreprésentée, puisqu'environ 36,0 % des nouveaux cas étaient d'origine autochtone. Une présentation tardive était fréquente partout, la numération de CD4 étant inférieure à 200 cellules/mm3 à la présentation dans 35,1 % des cas. EXPOSÉ: Les contacts hétérosexuels constituent le principal risque déclaré d'acquisition du VIH, mais la consommation de drogues par injection demeure importante en Saskatchewan. Les Autochtones sont surreprésentés partout, et en Saskatchewan, ils représentent la majorité des nouveaux cas observés. Contrairement aux tendances nationales, le nombre de nouveaux diagnostics et de diagnostics tardifs augmente dans les provinces des Prairies, ce qui a des répercussions thérapeutiques importantes et des conséquences potentielles en matière de santé publique. Il faut faire davantage d'efforts pour favoriser la tenue de tests et des mises en relation plus rapides vers les soins.

Heart Failure after Laboratory Confirmed Influenza Infection (FLU-HF).

Background: Influenza has been shown to exacerbate heart failure (HF). Importantly, no study to date has examined the relationship between HF hospitalizations (HFH) with laboratory confirmed influenza infections. This study evaluated the association between laboratory confirmed influenza infection and HFH in the two largest hospitals in Saskatchewan, Canada. Methods: We used a retrospective self-controlled case series design to evaluate the association between laboratory-confirmed influenza infection and HFH. We compared the incidence ratio for HFH during the influenza risk interval with the control interval. We defined the influenza risk interval as the seven days after a laboratory confirmed influenza result and the control interval as one year before and after the risk interval. Results: We identified 114 HFH that occurred within one year before and after a positive test result for influenza between April 1, 2010, and April 30, 2018. Of these, 28 (28 admissions per week) occurred during the risk interval and 86 (0.853 admissions per week) occurred during the control interval. The incidence ratio of a HFH during the risk interval as compared with the control interval was 33.53 (95% confidence interval [CI], 21.89 to 51.36). A decline in incidence was observed after day seven; between days 8 to 14 and 14 to 28 incidence ratios was 0.91 (95% CI, 0.13 to 6.52) and 0.91 (95% CI, 0.22 to 3.68) respectively. Conclusion: We have observed a significant association between acute influenza infection and HFH. However, further research with a larger sample size and involving a multicenter setting is warranted. Highlights: Influenza may contribute and exacerbate heart failure events especially during annual influenza season.Early identification of influenza among patients with heart failure, could lead to earlier treatment with antiviral medication, reduce unnecessary antibiotic use, and tail off the morbidity and mortality.In this study, despite our efficient study design, our sample size was limited to only the two largest hospitals in the province, possibly excluding a significant population in remote areas.

Trends in Use of Combination Antiretroviral Therapy and Treatment Response from 2000 to 2016 in the Canadian Observational Cohort (CANOC): A Longitudinal Cohort Study.

Background: Advances in treatment have turned HIV from a terminal illness to a more manageable condition. Over the past 20 years, there have been considerable changes to HIV treatment guidelines, including changes in preferred antiretrovirals and timing of initiation of combination antiretroviral therapy (cART). Objective: To examine real-world trends in cART utilization, viral control, and immune reconstitution among people living with HIV in Canada. Methods: Data were obtained from the Canadian Observational Cohort (CANOC). CANOC participants were eligible if they were antiretroviral therapy-naive at entry and initiated 3 or more antiretrovirals on or after January 1, 2000; if they were at least 18 years of age at treatment initiation; if they were residing in Canada; and if they had at least 1 viral load determination and CD4 count within 1 year of CANOC entry. Baseline and annual mean CD4 counts were categorized as less than 200, 200-350, 351-500, and more than 500 cells/mm3. Annual mean viral loads were reported as suppressed (< 50 copies/mL), low (50-199 copies/mL), or high detectable (≥ 200 copies/mL). The cART regimens were reported yearly. Results: All CANOC participants were included (n = 13 040). Over the study period, the proportion of individuals with an annual mean CD4 count above 500 cells/mm3 increased from 16.3% to 65.8%, while the proportion of individuals with an undetectable mean viral load increased from 10.6% to 83.2%. As of 2007, the most commonly prescribed 2-agent nucleoside reverse transcriptase inhibitor backbone was tenofovir disoproxil fumarate and emtricitabine. In terms of third agents, non-nucleoside reverse transcriptase inhibitors were the most common class in the periods 2000-2003 and 2014-2015, protease inhibitors were most common in the period 2004-2013, and integrase inhibitors were most common in 2016. Conclusions: Concordance with treatment guidelines was demonstrated over time with respect to cART prescribing and immunologic and virologic response.

Contexte: Les progrès effectués dans le domaine des traitements ont transformé le VIH. Celui-ci est passé d'une maladie en phase terminale à une maladie plus gérable. Au cours des 20 dernières années, des changements considérables ont eu lieu dans les directives de traitement du VIH, y compris des changements dans les antirétroviraux privilégiés et le moment de l'initiation de la thérapie antirétrovirale combinée (TARc). Objectif: Examiner les tendances réelles de l'utilisation de la TARc, du contrôle viral et de la reconstitution immunitaire chez les personnes vivant avec le VIH au Canada. Méthodes: Les données ont été obtenues auprès de la Canadian Observational Cohort (CANOC). Les participants à la CANOC étaient admissibles s'ils n'avaient jamais reçu de traitement antirétroviral à l'entrée et avaient commencé la prise de 3 antirétroviraux ou plus le 1er janvier 2000 ou après cette date; s'ils avaient au moins 18 ans au moment du début du traitement; s'ils résidaient au Canada; et s'ils avaient au moins 1 charge virale et un nombre de CD4 dans l'année suivant l'entrée à la CANOC. Les numérations initiales et annuelles moyennes de CD4 ont été classées comme inférieures à 200, 200 à 350, 351 à 500, et supérieures à 500 cellules/mm3. Les charges virales moyennes annuelles ont été signalées comme supprimées (< 50 copies/mL), faibles (50 à 199 copies/mL) ou élevées détectables (≥ 200 copies/mL). Les régimes de la TARc ont été rapportés chaque année. Résultats: Tous les participants à la CANOC ont été inclus (n = 13040). Au cours de la période d'étude, la proportion de personnes ayant une numération CD4 moyenne annuelle supérieure à 500 cellules/mm3 est passée de 16,3 % à 65,8 %, tandis que la part de personnes ayant une charge virale moyenne indétectable est passée de 10,6 % à 83,2 %. En 2007, la bithérapie de base d'inhibiteurs nucléosidiques de la transcriptase inverse la plus couramment prescrite était le fumarate de ténofovir disoproxil et l'emtricitabine. En matière de troisièmes agents, la classe la plus courante dans les périodes 2000­2003 et 2014­2015 était les inhibiteurs non nucléosidiques de la transcriptase inverse; les plus courants dans la période 2004­2013 étaient les inhibiteurs de protéase; et les inhibiteurs de l'intégrase étaient les plus courants en 2016. Conclusions: La concordance avec les directives de traitement a été démontrée au fil du temps en ce qui concerne la prescription de la cART et la réponse immunologique et virologique.

Detecting latent tuberculosis infection during anti-tumor necrosis factor therapy.

OBJECTIVES: There is little information regarding the reliability of repeat tuberculin skin tests (TSTs) and interferon gamma release assays (IGRAs) in detecting latent tuberculosis infection (LTBI) in people on anti-tumour necrosis factor (TNF) medication. METHODS: We conducted a prospective, observational study of patients referred to the Saskatoon Tuberculosis (TB) Clinic prior to starting anti-TNF medication. A chest x-ray (CXR), 2-step TST and IGRA (QuantiFERON-TB Gold In-Tube Method) were performed at baseline. Those patients with a baseline TST ≥10 mm and/or a positive IGRA were followed with a clinic visit, CXR, TST and IGRA at 3 and 6 months after starting anti-TNF medication. RESULTS: Of 106 potential patients, 91 consented to participate. Twenty-six patients had a positive (≥ 10 mm) TST or IGRA at baseline; twelve started and stayed on anti-TNF medication through the 6-month follow-up and completed both planned follow-up visits. The baseline mean TST measurement for the 12 participants was 13.9 mm (SD 11.4), increasing to a mean of 16.8 mm (SD 9.3) post-booster. At 3 months post-anti-TNF initiation, there was an overall decrease in TST measurement (mean=10.0 mm; SD 9.3; p=0.013), with measurements <5 mm in 3 of the 12 patients. By the 6-month TST, a response recovery was observed with a mean TST measurement of 14.5 mm (SD 7.7), with 11/12 ≥5 mm. The IGRA was unchanged throughout the study period in all patients. The overall agreement between TST and IGRA was poor (kappa coefficient = 0.180, p=0.020). CONCLUSIONS: We demonstrated a transient but significant decrease in TST response in the first six months of anti-TNF therapy.

Recovery of borderline oxacillin-resistant Staphylococcus pseudintermedius (BORSP) from bone and soft tissue of a rheumatoid arthritis patient with severe osteoporosis: transmission from the family dog.

We report a case of borderline oxacillin-resistant S. pseudintermedius (BORSP) in a rheumatoid arthritis patient with severe osteoporosis. The organism is also resistant to erythromycin and clindamycin. We also present clear evidence on transmission from the family dog.

Clinical and demographic predictors of antiretroviral efficacy in HIV-HBV co-infected patients.

Background: The clinical and demographic characteristics that predict antiretroviral efficacy among patients co-infected with HIV and hepatitis B virus (HBV) remain poorly defined. We evaluated HIV virological suppression and rebound in a cohort of HIV-HBV co-infected patients initiated on antiretroviral therapy. Methods: A retrospective cohort analysis was performed with Canadian Observation Cohort Collaboration data. Cox proportional hazards models were used to determine the factors associated with time to virological suppression and time to virological rebound. Results: HBV status was available for 2,419 participants. A total of 8% were HBV co-infected, of whom 95% achieved virological suppression. After virological suppression, 29% of HIV-HBV co-infected participants experienced HIV virological rebound. HBV co-infection itself did not predict virological suppression or rebound risk. The rate of virological suppression was lower among patients with a history of injection drug use or baseline CD4 cell counts of <199 cells per cubic millimetre. Low baseline HIV RNA and men-who-have-sex-with-men status were significantly associated with a higher rate of virological suppression. Injection drug use and non-White race predicted viral rebound. Conclusions: HBV co-infected HIV patients achieve similar antiretroviral outcomes as those living with HIV mono-infection. Equitable treatment outcomes may be approached by targeting resources to key subpopulations living with HIV-HBV co-infection.

Historique: Les caractéristiques cliniques et démographiques prédictives de l'efficacité antirétrovirale chez les patients co-infectés par le virus de l'immunodéficience humaine (VIH) et le virus de l'hépatite B (VHB) demeurent mal définies. Les chercheurs ont évalué la suppression et le rebond virologiques du VIH dans une cohorte de patients co-infectés par le VIH et le VHB chez qui on avait entrepris un traitement antirétroviral. Méthodologie: Les chercheurs ont réalisé une analyse rétrospective de cohorte à l'aide des données de la Canadian Observation Cohort Collaboration. Ils ont utilisé le modèle à risques proportionnels de Cox pour déterminer les facteurs associés à la période jusqu'à la suppression et au rebond virologiques. Résultats: Les chercheurs ont obtenu le statut de VHB de 2 419 participants. Au total, 8 % étaient co-infectés par le VHB, dont 95 % présentaient une suppression virologique. Après la suppression virologique, 29 % des participants co-infectés par le VIH et le VHB ont subi un rebond virologique du VIH. En elle-même, la co-infection par le VHB n'était pas prédictive de la suppression virologique ou du risque de rebond. Le taux de suppression virologique était plus faible chez les patients ayant des antécédents de consommation de drogues injectables ou une numération des cellules CD4 de référence de moins de 199 cellules par millimètre cube. Un ARN du VIH de référence bas et les hommes ayant des relations sexuelles avec des hommes étaient associés de manière significative avec un taux plus élevé de suppression virologique. La consommation de drogues injectables et les races non blanches étaient prédictives d'un rebond viral. Conclusion: Les patients atteints du VHB co-infectés par le VIH obtenaient des résultats antirétroviraux semblables à ceux qui étaient seulement infectés par le VIH. On peut anticiper des résultats cliniques équitables des traitements en ciblant les ressources vers les sous-populations atteintes d'une co-infection par le VIH et le VHB.

Methicillin-resistant Staphylococcus aureus replication in the presence of high (≥32 µg/ml) drug concentration of vancomycin as seen by electron microscopy.

Methicillin-resistant Staphylococcus aureus (MRSA) has unfortunately become a common pathogen in many healthcare facilities. In many institutions, vancomycin remains the preferred agent for treating serious MRSA infections including bacteraemia with or without endocarditis. The mutant prevention concentration (MPC) testing ≥109 colony forming units of bacteria, describes the antimicrobial drug concentration blocking the growth of the least susceptible cell from high density bacterial populations. With blood culture isolates of MRSA, we discovered strains with MPC values ≥32 µg/ml and viable cells could be readily recovered from agar plates containing 32 µg/ml of vancomycin. To investigate MRSA strains surviving in high concentrations of vancomycin on drug containing agar plates, we utilized electron microscopy to measure cell wall thickness as this has been previously reported as a potential mechanism of resistance1 along with septum thickening. Our data shows MRSA replication from high density bacterial populations in the presence of ≥32 µg/ml of vancomycin. Such observations may explain vancomycin failure in some patients and/or persistent bacteraemia and could potentially question the use of this drug in some critically ill patients in favour of an alternative agent.

Bacteremia with Staphylococcus pseudintermedius in a 4 month old pediatric oncology patient.

Staphylococcus pseudintermedius colonizes and is a pathogen of dogs and is being increasingly recognized from specimens from humans with various infections. We describe a case of S. pseudintermedius bacteremia in a 4 month old pediatric oncology patient with clear evidence of transmission from the family pet.

Comparison of various radioactive payloads for a human monoclonal antibody to glycoprotein 41 for elimination of HIV-infected cells.

BACKGROUND: cART has significantly improved the life expectancy of people living with HIV (PLWH). However, it fails to eliminate the long-lived reservoir of latent HIV-infected cells. Radioimmunotherapy (RIT) relies on antigen-specific monoclonal antibodies (mAbs) for targeted delivery of lethal doses of ionizing radiation to cells. Previously, we have demonstrated that human mAb 2556 against HIV gp41 conjugated with 213Bismuth radioisotope (t1/2 = 46 min, alpha-emitter) selectively killed HIV-infected cells. 225Actinium (t1/2 = 9.92 d, alpha-emitter) and 177Lutetium (t1/2 = 6.7 d, beta-emitter) are two long-lived clinically proven radioisotopes for cancer treatment which might be more effective in killing infected cells systemically and in CNS. METHODS: In this study we have conjugated 2556 mAb with 213Bi, 225Ac and 177Lu, and compared their ability to kill HIV-infected human peripheral blood mononuclear cells (PBMCs) and monocytes. PBMCs and monocytes from healthy donors were infected with HIVp49.5 and treated in vitro with increasing concentrations of 213Bi (4-20 µCi)-, 225Ac (20-100 nCi)- and 177Lu (4-50 µCi)-2556 mAb. RESULTS: After three days post-treatment of infected PBMCs and monocytes, 213Bi- and 177Lu-conjugated 2556 mAb reduced virus production measured by p24 level in a dose-dependent manner, whereas, 225Ac-2556 showed minimal effect. However, seven days post-treatment all three radioisotopes showed significantly more pronounced reduction of virus replication as compared to control labeled mAb with 225Ac-2556 showing the least non-specific killing. CONCLUSION: These results indicate that RIT holds promise as a novel treatment option for the eradication of HIV-infected cells that merits further study in combination with cART and reactivation drugs.

Polymorphisms of the cytidine deaminase APOBEC3F have different HIV-1 restriction efficiencies.

The APOBEC3 enzyme family are host restriction factors that induce mutagenesis of HIV-1 proviral genomes through the deamination of cytosine to form uracil in nascent single-stranded (-)DNA. HIV-1 suppresses APOBEC3 activity through the HIV-1 protein Vif that induces APOBEC3 degradation. Here we compared two common polymorphisms of APOBEC3F. We found that although both polymorphisms have HIV-1 restriction activity, APOBEC3F 108 A/231V can restrict HIV-1 ΔVif up to 4-fold more than APOBEC3F 108 S/231I and is partially protected from Vif-mediated degradation. This resulted from higher levels of steady state expression of APOBEC3F 108 A/231 V. Individuals are commonly heterozygous for the APOBEC3F polymorphisms and these polymorphisms formed in cells, independent of RNA, hetero-oligomers between each other and with APOBEC3G. Hetero-oligomerization with APOBEC3F 108 A/231V resulted in partial stabilization of APOBEC3F 108 S/231I and APOBEC3G in the presence of Vif. These data demonstrate functional outcomes of APOBEC3 polymorphisms and hetero-oligomerization that affect HIV-1 restriction.

Zebularine inhibits human acute myeloid leukemia cell growth in vitro in association with p15INK4B demethylation and reexpression.

OBJECTIVE: The p15INK4B tumor suppressor is frequently silenced by promoter hypermethylation in myelodysplastic syndrome and acute myeloid leukemia (AML). Clinically approved DNA methylation inhibitors, such as 5-aza-2'-deoxycytidine, can reverse p15INK4B promoter methylation, but widespread clinical use of these inhibitors is limited by their toxicity and instability in aqueous solution. The cytidine analog zebularine is a stable DNA methylation inhibitor that has minimal toxicity in vitro and in vivo. We evaluated zebularine effects on p15INK4B reactivation and cell growth in vitro to investigate a potential role for zebularine in treating myeloid malignancies. METHODS: We examined the specific effects of zebularine on reexpression of transcriptionally silenced p15INK4B and its global effects on cell cycle and apoptosis in AML cell lines and primary patient samples. RESULTS: Zebularine treatment of AML193, which has a densely methylated p15INK4B promoter, results in a dose-dependent increase in p15INK4B expression that correlates with CpG island promoter demethylation and enrichment of local histone acetylation. We observed enhanced p15INK4B induction following co-treatment with zebularine and the histone deacetylase inhibitor Trichostatin A. Zebularine inhibits cell proliferation, arrests cells at G(2)/M, and induces apoptosis at dosages that effectively demethylate the p15INK4B promoter. Zebularine treatment of KG-1 cells and AML patient blasts with hypermethylated p15INK4B promoters also reactivates p15INK4B reexpression and induces apoptosis. CONCLUSION: Zebularine is an effective inhibitor of p15INK4B methylation and cell growth in human AML in vitro. Our results extend the spectrum of zebularine effects to nonepithelial malignancies and provide a strong rationale for evaluating its clinical utility in the treatment of myeloid malignancies.

Extensive host immune adaptation in a concentrated North American HIV epidemic.

OBJECTIVE: HIV incidence in the Canadian province of Saskatchewan, where Indigenous persons make up 80% of those infected, are among the highest on the continent. Reports of accelerated HIV progression, associated with carriage of certain human leukocyte antigen (HLA) alleles (including the typically protective HLA-B*51) have also emerged from the region. Given that acquisition of HIV preadapted to host HLA negatively impacts clinical outcome, we hypothesized that HIV-host adaptation may be elevated in Saskatchewan. DESIGN: Comparative analysis of population-level HIV sequence datasets from Saskatchewan and elsewhere in Canada/USA. METHODS: We analyzed 1144 HIV subtype B Pol sequences collected in Saskatchewan between 2000 and 2016, comprising ∼65% of cumulative provincial HIV cases, for the presence of 70 HLA-associated Pol mutations. Sequences from British Columbia (N = 6525) and elsewhere in Canada/USA (N = 6517) were used for comparison. HIV adaptation levels to 34 HLA alleles were also computed. Putative HIV transmission clusters were identified, and the prevalence of HLA-associated adaptations within and outside these clusters was investigated. RESULTS: Analyses confirmed significantly elevated and temporally increasing levels of HIV adaptation to commonly expressed HLA alleles, in particular B*51. Notably, HLA-adapted HIV strains were significantly enriched among phylogenetic clusters in Saskatchewan. CONCLUSION: Extensive circulating HIV adaptation to HLA in Saskatchewan provides a plausible explanation for accelerated progression, while enrichment of adapted variants in phylogenetic clusters suggests they are being widely transmitted. Results highlight the utility of Pol sequences, routinely collected for drug resistance monitoring, for surveillance of HIV-host adaptation, and underscore the urgent need to expand HIV prevention and treatment programmes in Saskatchewan.

5-Aza-2'-deoxycytidine (decitabine) can relieve p21WAF1 repression in human acute myeloid leukemia by a mechanism involving release of histone deacetylase 1 (HDAC1) without requiring p21WAF1 promoter demethylation.

Decitabine is a potent demethylating agent that exhibits clinical activity against myeloid malignancies. Numerous genes silenced by hypermethylation are reactivated by decitabine through a mechanism involving promoter demethylation with subsequent release of histone deacetylases (HDACs) and accumulation of acetylated histones. Recent studies indicating that decitabine also induces regional chromatin remodeling of some unmethylated genes suggest additional mechanisms of action. Decitabine reactivates unmethylated p21WAF1 in some AML cell lines but the possible occurrence of p21WAF1 methylation in AML in vivo has not been studied in detail and decitabine effects on p21WAF1 chromatin remodeling have not been reported. We found that p21WAF1 mRNA was undetectable in 6 of 24 AML patient samples and 4 of 5 AML cell lines but there was no evidence of p21WAF1 promoter methylation. However, decitabine induced p21WAF1 in AML cell lines KG-1 and KG-1a in association with release of HDAC1 and increased acetylated histone H3 at the unmethylated p21WAF1 promoter. Decitabine effects on p21WAF1 histone acetylation and induction were enhanced by the HDAC inhibitor trichostatin A and were independent of wild type p53. Our findings indicate that decitabine can relieve p21WAF1 repression in AML by a mechanism that involves release of HDAC1 without requiring promoter demethylation. Furthermore, our study provides evidence that combined decitabine and HDAC inhibitor treatment can enhance chromatin remodeling and reactivation of an unmethylated tumor suppressor gene. This latter finding is of relevance to the clinical use of these agents in AML as we found the p21WAF1 promoter to be unmethylated in vivo.

Propionibacterium acnes infections after cranial neurosurgery.

BACKGROUND: Propionibacterium acnes (P. acnes) is a relatively avirulent organism that is part of the normal skin flora. Most patient isolates are considered contaminants but, in a small subset of patients, particularly in the post-neurosurgery setting, the organism can cause significant infections. We reviewed our experience with the occurrence and management of P. acnes infections after cranial neurosurgical procedures over a five-year period. METHODS: Patients with positive cultures for P. acnes between 1996 and 2001 were identified by review of the Saskatoon Health Region microbiology laboratory database. Of the 141 positive cultures, a review of hospital records identified six patients with P. acnes infections after neurosurgical procedures. A review of the literature related to P. acnes associated CNS infections was conducted. RESULTS: All patients had undergone a craniotomy or burrhole placement, and one patient had received prior radiotherapy. There were no P. acnes-related ventriculoperitoneal shunt infections. All patients presented with scalp swelling and three had purulent discharge. Symptoms occurred more than two months after the initial surgery in five of six patients, while one patient developed symptoms three years post-operatively. Management for all patients included removal of the craniotomy flap and treatment with parenteral antibiotics, followed in most cases by oral antibiotics. A good response without relapse of infection was seen in five patients; one patient had recurrent infection after cranioplasty. CONCLUSIONS: P. acnes is a rare but important cause of infection after craniotomy. Wound debridement, removal of the bone flap and adequate antibiotic coverage result in cure in the majority of patients.