Low Viremia Research Articles

Interferon Alpha-Inducible Protein 27 Expression Is Linked to Disease Severity in Chronic Infection of Both HIV-1 and HIV-2

Disease progression is slower in HIV-2, as compared with HIV-1 infection, in accordance with low or undetectable plasma viremia at viral setpoint. However, it is unclear why most HIV-2 infected individuals are still at risk of developing AIDS. To explore if specific host responses are linked to HIV disease severity, we have compared blood gene expression profiles between HIV seronegative and HIV-1, HIV-2 or dually HIV-1/HIV-2 infected individuals. In this study the gene encoding Interferon alpha-inducible protein 27 (IFI27) was found to be the most differentially expressed. Detailed expression analysis revealed significantly higher IFI27 expression in HIV infected individuals compared with seronegative individuals, irrespectively of HIV type. Moreover, IFI27 expression was higher in HIV-1 than in HIV-2 infected individuals. Multiple linear regression analysis, adjusting for age and sex, showed also that plasma viral load was the strongest predictor of IFI27 expression, followed by CD4% and HIV type. In line with this, IFI27 expression was found to be higher in HIV-2 viremic, compared with HIV-2 aviremic individuals. Still, HIV-2 aviremic individuals displayed elevated IFI27 expression compared with seronegative individuals. Furthermore, in HIV-2 infected individuals, IFI27 expression was also correlated with plasma markers previously linked to inflammation and disease progression in HIV infection. Taken together, our findings suggest that sustained elevation of type I interferon signaling, here reflected by elevated IFI27 expression in the chronic infection phase, is a key pathogenic feature of both HIV-1 and HIV-2.

New Aspects of the Virus Life Cycle and Clinical Utility of Next Generation Sequencing based HIV-1 Resistance Testing in the Genomic, the Proviral, and the Viral Reservoir of Peripheral Blood Mononuclear Cells.

Typically, genotypic resistance testing is recommended at the start of antiretroviral therapy and is even mandatory in cases of virologic failure. The material of choice is plasma viral RNA. However, in patients with low viremia (viral load < 500 copies/ml), resistance testing by population-based sequencing is very difficult. Therefore, we aimed to investigate whether next generation sequencing (NGS) from proviral DNA and RNA could be an alternative. EDTA blood samples (n = 36) from routine clinical viral load testing were used for the study. Viral loads ranged from 96 to 390,000 copies/mL, with 100% of samples having low viremia. Distribution of subtypes; A (n = 2), B (n = 16), C (n = 4), D (n = 2), G (1), CRF02 AG (n = 5), CRF01 AE (n = 5), undefined/mixed (n = 4). The extracted consensus sequences were uploaded to the Stanford HIV Drug Resistance Data Base and Geno2pheno for online analysis of drug resistance mutations and resistance factors. A total of 2476 variants or drug resistance mutations (DRMs) were detected with Sanger sequencing, compared with 2892 variants with NGS. An average of 822/1008 variants were identified in plasma viral RNA by Sanger or NGS sequencing, 834/956 in cellular viral RNA, and 820/928 in cellular viral DNA. Both methods are well suited for the detection of HIV substitutions or drug resistance mutations. Our results suggest that cellular RNA or cellular viral DNA is an informative alternative to plasma viral RNA for variant detection in patients with low viremia, as shown by the high correlation of variants in the different viral pools. We show that by using UDS, a plus of two DRMs per patient becomes visible, which can make a big difference in the assessment of the expected resistance behavior of the virus.

Minor and major envelope proteins of PRRSV play synergistic roles in inducing heterologous neutralizing antibodies and conferring cross protection

High genetic diversity of porcine reproductive and respiratory syndrome virus (PRRSV) isolates is a major obstacle for the development of effective PRRS vaccines. A chimeric highly pathogenic PRRSV2 (HP-PRRSV2) strain containing the consensus sequence of ORF2-6 genes was constructed in our previous study, which could induce broadly neutralizing antibodies (bnAbs) and confer satisfied cross protection against virulent NADC30-like isolate. To further elucidate the roles of minor and major envelope proteins encoded by ORF2-4 and ORF5-6 genes in conferring cross protection, two chimeric HP-PRRSV2 strains (rJS-ORF2-4-CON and rJS-ORF5-6-CON) containing consensus sequences of ORF2-4 or ORF5-6 were constructed and rescued in this study. The rJS-ORF5-6-CON strain has similar replication efficiency as the backbone HP-PRRSV2 rJSTZ1712-12 virus, while rJS-ORF2-4-CON has significantly lower in vitro and in vivo replication efficiency comparing to rJS-ORF5-6-CON. Animal inoculation indicated that both rJS-ORF2-4-CON and rJS-ORF5-6-CON did not cause obvious clinical signs in piglets and could induce heterologous nAbs after immunization. Challenge with a virulent heterologous NADC30-like SD17-38 isolate showed that even though both immunized groups presented lower viremia, faster virus elimination, less fever and alleviated lung gross lesions when compared with the only challenged pigs, rJS-ORF2-4-CON and rJS-ORF5-6-CON could not confer enough cross protection. Considering the bnAbs and satisfied cross protection induced by the chimeric virus containing ORF2-6 consensus sequence, our results support that minor and major envelope proteins play synergistic roles in inducing broader nAbs and conferring better cross protection.

Biodistribution and environmental safety of a live-attenuated YF17D-vectored SARS-CoV-2 vaccine candidate

New platforms are needed for the design of novel prophylactic vaccines and advanced immune therapies. Live-attenuated yellow fever vaccine YF17D serves as a vector for several licensed vaccines and platform for novel candidates. On the basis of YF17D, we developed an exceptionally potent COVID-19 vaccine candidate called YF-S0. However, use of such live RNA viruses raises safety concerns, such as adverse events linked to original YF17D (yellow fever vaccine-associated neurotropic disease [YEL-AND] and yellow fever vaccine-associated viscerotropic disease [YEL-AVD]). In this study, we investigated the biodistribution and shedding of YF-S0 in hamsters. Likewise, we introduced hamsters deficient in signal transducer and activator of transcription 2 (STAT2) signaling as a new preclinical model of YEL-AND/AVD. Compared with YF17D, YF-S0 showed improved safety with limited dissemination to brain and visceral tissues, absent or low viremia, and no shedding of infectious virus. Considering that yellow fever virus is transmitted by Aedes mosquitoes, any inadvertent exposure to the live recombinant vector via mosquito bites is to be excluded. The transmission risk of YF-S0 was hence compared with readily transmitting YF-Asibi strain and non-transmitting YF17D vaccine, with no evidence for productive infection of mosquitoes. The overall favorable safety profile of YF-S0 is expected to translate to other vaccines based on the same YF17D platform.

Vesicular MicroRNA as Potential Biomarkers of Viral Rebound.

Changes in the cellular microRNA (miRNA) expression profile in response to HIV infection, replication or latency have been reported. Nevertheless, little is known concerning the abundance of miRNA in extracellular vesicles (EVs). In the search for a reliable predictor of viral rebound, we quantified the amount of miR-29a, miR-146a, and miR-155 in two types of plasma extracellular vesicles. Venous blood was collected from 235 ART-treated and ART-naive persons living with HIV (85 with ongoing viral replication, ≥20 copies/mL) and 60 HIV-negative participants at five HIV testing or treatment centers in Burkina Faso. Large and small plasma EVs were purified and counted, and mature miRNA miR-29a, miR-146a, and miR-155 were measured by RT-qPCR. Diagnostic performance of miRNA levels in large and small EVs was evaluated by a receiver operating characteristic curve analysis. The median duration of HIV infection was 36 months (IQR 14–117). The median duration of ART was 34 months (IQR 13–85). The virus was undetectable in 63.8% of these persons. In the others, viral load ranged from 108 to 33,978 copies/mL (median = 30,032). Large EVs were more abundant in viremic participants than aviremic. All three miRNAs were significantly more abundant in small EVs in persons with detectable HIV RNA, and their expression levels in copies per vesicle were a more reliable indicator of viral replication in ART-treated patients with low viremia (20–1000 copies/mL). HIV replication increased the production of large EVs more than small EVs. Combined with viral load measurement, quantifying EV-associated miRNA abundance relative to the number of vesicles provides a more reliable marker of the viral status. The expression level as copies per small vesicle could predict the viral rebound in ART-treated patients with undetectable viral loads.

A bivalent porcine circovirus type 2 (PCV2), PCV2a-PCV2b, vaccine offers biologically superior protection compared to monovalent PCV2 vaccines

Recent publications suggest PCV2 vaccine-induced protection is superior when the vaccine and challenge are closely matched. PCV2’s evolutionary rate, propensity for recombination, and genotype shifting, all provide rationale for modernizing PCV2 vaccines. One mechanism to increase a vaccine’s epitope breadth is by designing a bivalent vaccine. The objective of these studies was to evaluate efficacy of a monovalent (PCV1-2 chimera, cPCV2a or cPCV2b) and bivalent (cPCV2a–cPCV2b) vaccine in terms of homologous and heterologous efficacy. In Study A, pigs were vaccinated with cPCV2a or saline and challenged with PCV2a or PCV2b. In Study B, pigs were vaccinated with cPCV2a, cPCV2a–cPCV2b bivalent, or saline, and challenged with PCV2a. In Study C, pigs were vaccinated with cPCV2b, cPCV2a–cPCV2b bivalent, or saline, and challenged with PCV2b. In all studies vaccines and saline were administered intramuscularly to pigs at three to four weeks of age. Virulent PCV2b or PCV2a was administered to all animals approximately three weeks post-vaccination. Both mono and bivalent vaccinated groups demonstrated significantly lower viremia, percent of animals ever viremic, percent of animals with lymphoid depletion and/or histiocytic replacement, and percent of animals with PCV2 colonization of lymphoid tissues compared to saline controls. In Study A, a biologically relevant, though not significantly different, improvement in homologous versus heterologous protection was observed. In Studies B and C, biologically superior efficacy of the bivalent cPCV2a–cPCV2b vaccine compared to either monovalent vaccine was demonstrated. Taken together, cross-protection among mismatched PCV2 vaccine and challenge genotypes is not 100%; a bivalent PCV2 vaccine may provide the best opportunity to broaden coverage to circulating strains of PCV2.

Development of IgM-ELISA for diagnosis of recent infection of Japanese encephalitis virus in equines

Japanese encephalitis (JE) is a re-emerging mosquito borne disease, for which equines are most susceptible amongst all animals. Detection of specific immunoglobulin ‘M’ (IgM) is considered as an ideal way to diagnose recent JE virus infection in equines due to low virus load and short-term viremia. The present study was undertaken to develop a sensitive and specific recombinant NS1 protein based indirect IgM-ELISA and IgM capture (MAC) ELISA to diagnose recent infection of JEV in equines. Indirect IgM ELISA was standardized with relative diagnostic sensitivity and specificity of 100% and 88.5%, respectively. The validation of indirect IgM-ELISA in different laboratories revealed excellent reproducibility with Cohen's kappa value ranging between 0.84 and 1. The standardization of MAC ELISA was attempted using checker board titration method and non-specific binding of polyclonal anti-equine IgM capture antibody with anti-porcine IgG conjugate and with hyperimmune serum raised in swine against the antigen was observed. Hence, the MAC ELISA was standardized with monoclonal capture antibody; however, its diagnostic performance could not meet the satisfactory limit. Due to better sensitivity and less turnaround time, indirect IgM-ELISA was employed to screen 821 equine serum samples revealing 33.73% positivity of IgM antibodies against JEV in equine population of India. The high JEV sero-positivity warrants the need for vaccination in Indian equine population along with the demand for research focused towards anti-viral therapy. The indirect IgM-ELISA developed in the present study could be useful to diagnose acute or recent infection of JEV in equines as well as in sero-epidemiological studies.

Italian migrants study: An HCV and HBV micro-elimination pilot project

BackgroundMigrants represent a key target population for viral hepatitis micro-elimination programs and are important targets for specific prevention, screening and treatment programs. AimsTo raise awareness on viral hepatitis among migrants and key stakeholders, assess the prevalence of HBV and HCV among migrants, and determine an optimal and scalable viral hepatitis screening and treatment protocol. Material and methodsUnselected, consecutive migrants reaching the costs of Italy were screened for HBV, HCV, HDV and HIV markers. Anagraphic and anamnestic information were used to identify viral hepatitis endemic hotspots in the countries of birth or transit. Personal data, including migration route, test results and treatment, were collected and stored in a dedicated database Results362 patients were recruited in 2019; median age was 28 years, 71% were male. Most of the patients were African (54%) or Asian (40%). 49% positive for at least one HBV marker: 2.2% HBsAg (asymptomatic carriers with low viremia); 10.6% anti-HBs; 28.5% anti-HBs and anti-HBc, 1.7% anti-HCV, 0.6% anti-HIV, with low or undetectable viral load. Libya was the nexus shared by most of the positive, reactive cases. HCV and HIV markers were only found in migrants already resident in Italy for more than 6–12 months. ConclusionLow to moderate prevalence of hepatitis B markers were observed in African and Asian first arrival migrants. Migrants positive for HCV and HIV likely acquired the infection after arrival in Italy, suggesting migrants are at risk of contracting viral infections once in Italy, highlighting the importance of ensuring access to prevention for migrant communities.

940. The use of a commercially available CMV T Cell Immunity Panel to Assess the Risk of CMV Infections in Hematopoietic Cell Transplant Recipients with Low Level CMV Viremia

BackgroundCytomegalovirus (CMV) infections continue to be associated with increased morbidity and mortality in Hematopoietic Cell Transplant (HCT) recipients. Treatment of high risk patients with low level viremia may reduce overall duration of therapy and reduce complications. CMV T Cell Immunity Panel (TCIP) may help identify patients at high risk of CMV reactivation prior to developing clinically significant CMV infection (CS-CMVi). Our study aims to identify HCT recipients with low level CMV viremia who are at high risk of CMV reactivation with the use of CMV-TCIP while on or off letermovir for prophylaxis. MethodsWe enrolled in a prospective cohort study allogeneic HCT recipients (excluding cord blood transplantation) with low level of CMV viremia (viral load of < 1000 IU/ml) on no therapy, starting October 2019. CMV TCIP assay was performed at enrollment, weeks 1, 2, 3, 4, 6 and 8. CMV TCIP results were interpreted as negative or positive based on percentage of interferon gamma producing CD4+ or CD8+ CMV specific T cells. The primary endpoint was progression to a CS-CMVi. We are presenting the results of the first 30 patients with data up to 4 weeks from enrollment.ResultsAmong the 30 patients, 73% were on letermovir for CMV prophylaxis. Majority of the patients were ≥ 40 years old (77%), male (63%), received transplant for AML (40%), were in complete remission at time of transplant (23%) and received cyclophosphamide (90%). The median time from transplant to enrollment was 77 days (IQR 37-172) (table 1). At enrollment, 10 (33%) patients had a positive CMV TCIP, 10 (33%) had a negative CMV TCIP, and 10 (33%) had an uninterpretable CMV TCIP result due to inability to quantify T cells (table 1). Four (13%) patients developed CS-CMVi; 3 of these patients had a negative TCIP and 1 had unquantifiable CMV TCIP (Figure 1). The mean percentage of CMV specific CD4+ and CD8+ interferon producing cells was 1.76% (SD 2.24) and 9.37% (SD 11.35) for those on letermovir and 2.09% (SD 2.05) and 3.97% (SD 5.24) off letermovir respectively (P >0.05) (Figure 2).Figure 1. Breakdown of the 30 patients during the 4 week follow up period Abbreviations: HCT: Hematopoietic cell transplantation; CMV: Cytomegalovirus; TCIP: T cell immunity panelFigure 2. Box-plot of percentage of CD4+ CMV specific interferon producing cells over time. Threshold for positive result (0.2%) marked. Abbreviations: CMV: CytomegalovirusTable 1. Baseline characteristics of patients enrolled Abbreviations: CMV: Cytomegalovirus; TCIP: T cell immunity panel; IQR: Interquartile rangeConclusionOur results demonstrate the value of the CMV TCIP in identifying high risk HCT recipients prior to developing CS-CMV infection. Disclosures Fareed Khawaja, MBBS, Eurofins Viracor (Research Grant or Support) Ella Ariza Heredia, MD, Merck (Grant/Research Support) Michelle Altrich, PhD, HCLD, Eurofins Viracor (Employee) Roy F. Chemaly, MD, MPH, FACP, FIDSA, AiCuris (Grant/Research Support)Ansun Biopharma (Consultant, Grant/Research Support)Chimerix (Consultant, Grant/Research Support)Clinigen (Consultant)Genentech (Consultant, Grant/Research Support)Janssen (Consultant, Grant/Research Support)Karius (Grant/Research Support)Merck (Consultant, Grant/Research Support)Molecular Partners (Consultant, Advisor or Review Panel member)Novartis (Grant/Research Support)Oxford Immunotec (Consultant, Grant/Research Support)Partner Therapeutics (Consultant)Pulmotec (Consultant, Grant/Research Support)Shire/Takeda (Consultant, Grant/Research Support)Viracor (Grant/Research Support)Xenex (Grant/Research Support)

Effect of HIV status and retinol on immunogenicity to oral cholera vaccine in adult population living in an endemic area of Lukanga Swamps, Zambia.

BackgroundWe set out to assess the impact of human immunodeficiency virus (HIV) and micronutrient deficiency as indicated by serum retinol levels on the immune responses to Oral Cholera Vaccine (Shanchol™) in a cohort of participants in Lukanga Swamps, Zambia. Cholera remains endemic in Zambia with vaccines being the only effective preventive measures. However, the effect of these vaccines on populations living with HIV has not been widely documented.MethodsHIV testing and confirmation was done using the Alere Determine™ HIV-1/2 and Uni-Gold™ kits while vibriocidal antibody assay was applied for vaccine immunogenicity. Serum retinol analysis was assessed by Shimadzu Prominence HCT-2010 High Performance Liquid Chromatography (HPLC). The primary outcome was log transformed geometric mean titre.ResultsFrom 47 participants screened for HIV, 51% (24) tested positive. There was a statistically significant reduction in Ogawa geometric mean ratio (GMR) by 67% (GMR = 0.33; 95% CI: -0.15, 0.76; p-value = 0.009) attributable to HIV positivity with a non-significant reduction in Inaba GMR by about 50% due to HIV positivity. When doubling of retinol levels modelled, GMR reduction against Ogawa were non-significant but that against Inaba resulted in a significant reduction in geometric mean titer (GMT) (GMT-0.33, C.I 0.16–0.66, p-value 0.002). At 1000copies/ml viral load cut off and 350 cells/μl CD4 counts, Ogawa GMT was two times higher 11.16 (95%CI: 8.20–15.19) versus 6.06 (95%CI: 4.04–9.10) in low viremia participants, and three times higher in above threshold CD4 count participants; 24.81 (95%CI: 18.94–32.50) versus 7.07 (95%CI: 5.22–9.58).ConclusionOur results show that while Shanchol™ is immunogenic in both HIV+/- individuals, HIV + participants responded poorly. Viral load and CD4 count affected vaccine immunogenicity. More research is required for detailed understanding of this in order to appropriately inform policy and practice.

Predictive Factors of Detectable Viral Load in HIV-Infected Patients.

Despite availability of effective antiretroviral therapy (ART), many HIV patients still have a detectable viral load (VL). Predictive factors of detectable VL are not well documented. This study was done at two large multidisciplinary HIV outpatient clinics at the Centre hospitalier de l'Université de Montréal (CHUM) and the McGill University Health Centre (MUHC). This is a retrospective case-control study of patients treated between 2016 and 2018. Cases had a VL ≥50 copies/mL in 2018. Controls had an undetectable VL from 2016 to 2018. Matching was based on gender and year of HIV diagnosis. Primary objective was to identify predictive factors of detectable VL. Secondary objectives included to identify predictive factors of virologic failure, low persistent viremia, and viral blip. A forward stepwise model selection by the Akaike Information Criterion of the conditional logistic regression was used to identify predictive factors. Two hundred cases were identified and matched with 200 controls. The cohort was mostly male (68.0%) with a median age of 54 years (21-83 years). Among cases, viral blip was the most common type of detectable VL (43.0%). The strong predictive factors for a detectable VL were adherence to ART and seeking health care services. Asylum seekers were less at risk of detectable VL. Adherence to ART was the only strong predictive factor for virologic failure. Three main predictive factors of detectable VL were identified in two ambulatory clinic hospitals in Montreal. Ascertaining these factors will allow for identification of patients more at risk of detectable VL.

Molecular and Serological Characterization of Hepatitis B Virus (HBV)-Positive Samples with Very Low or Undetectable Levels of HBV Surface Antigen.

Background: Gaps remain in the detection of nucleic acid test (NAT) yield and occult hepatitis B virus (HBV) infection (OBI) by current HBV surface antigen (HBsAg) assays. The lack of detection may be due to HBsAg levels below current assay detection limits, mutations affecting HBsAg assays or HBsAg levels, or the masking of HBsAg by antibody to HBsAg (anti-HBs). In this study, we evaluate the incremental detection of NAT yield and OBI from five diverse geographic areas by an improved sensitivity HBsAg assay and characterize the samples relative to the viral load, anti-HBs status, and PreS1–S2–S mutations. Included is a comparison population with HBV DNA levels comparable to OBI, but with readily detectable HBsAg (High Surface–Low DNA, HSLD). Methods: A total of 347 samples collected from the USA, South Africa, Spain, Cameroon, Vietnam, and Cote D’Ivoire representing NAT yield (HBsAg(−), antibody to HBV core antigen (anti-HBc)(−), HBV DNA(+), N = 131), OBI (HBsAg(−), anti-HBc(+), HBV DNA(+), N = 188), and HSLD (HBsAg(+), anti-HBc(+), HBV DNA(+), N = 28) were tested with ARCHITECT HBsAg NEXT (HBsAgNx) (sensitivity 0.005 IU/mL). The sequencing of the PreS1–S2–S genes from a subset of 177 samples was performed to determine the genotype and assess amino acid variability, particularly in anti-HBs(+) samples. Results: HBsAgNx detected 44/131 (33.6%) NAT yield and 42/188 (22.3%) OBI samples. Mean HBV DNA levels for NAT yield and OBI samples were lower in HBsAgNx(−) (50.3 and 25.9 IU/mL) than in HBsAgNx(+) samples (384.1 and 139.5 IU/mL). Anti-HBs ≥ 10 mIU/mL was present in 28.6% HBsAgNx(+) and 45.2% HBsAgNx(−) OBI, and in 3.6% HSLD samples. The genotypes were A1, A2, B, C, D, E, F, and H. There was no significant difference between HBsAgNx(−) and HBsAgNx(+) in the proportion of samples harboring substitutions or in the mean number of substitutions per sample in PreS1, PreS2, or S for the NAT yield or OBI (p range: 0.1231 to >0.9999). A total of 21/27 (77.8%) of HBsAgNx(+) OBI carried S escape mutations, insertions, or stop codons. HSLD had more PreS1 and fewer S substitutions compared to both HBsAgNx(−) and HBsAgNx(+) OBI. Mutations/deletions associated with impaired HBsAg secretion were observed in the OBI group. Conclusions: HBsAgNx provides the improved detection of NAT yield and OBI samples. Samples that remain undetected by HBsAgNx have exceptionally low HBsAg levels below the assay detection limit, likely due to low viremia or the suppression of HBsAg expression by host and viral factors.

S2857 DRESS Syndrome Potentially Induced by Carbamazepine and Triggered by CMV Viremia

Introduction: Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe adverse drug reaction that manifests with fever, rash with visceral organ involvement and hematological abnormalities. It can occur due to many etiological factors, here we present a case of DRESS that is potentially induced by carbamazepine and triggered by CMV viremia. Case Description/Methods: A 53-year-old male with a history of DM, neuropathy and HTN who presented for acute liver failure (ALF). He endorsed a mild rash after his 1st dose of mRNA COVID vaccine, with full resolution. After receiving his 2nd dose, he developed a diffuse rash with nausea, vomiting, fever and malaise within 72 hrs. He denied supplements, alcohol. Labs were remarkable for eosinophilia, hyponatremia, AST/ALT greater than 10x the ULN, ALP 567, Tbil 8.3, INR 1.9, ammonia 94. Autoimmune panel, drug toxicology screen, viral hepatitis panel with work up including varicella, HSV, EBV, HEV were negative except CMV IgG reactive with low CMV viremia 34 IU/ML. He was initially suspected to have COVID vaccine induced ALF due to temporal association. However, on review, he reported that he was started on carbamazepine for neuropathy ∼7wks prior to initial presentation. He was also evaluated for liver transplant due to jaundice and coagulopathy. Pt met RegiSCAR criteria for DRESS syndrome and was started on steroids. Liver biopsy showed liver injury with resolving eosinophilia not specific. Pt showed significant improvement in liver enzymes and clinical symptoms after 6 days of high dose PO steroids;he was eventually discharged on steroid taper. Discussion: DRESS syndrome has a latency period of about 2-8weeks between drug initiation and onset of symptoms. Although pathogenesis is unknown, it involves two mechanisms- drug-specific immune response and reactivation of human Herpesviridae with a subsequent antiviral response. We hypothesize that DRESS was induced by initiation of carbamazepine and triggered by CMV infection. This case indicates prompt diagnosis and steroids can be lifesaving in this rare presentation of DRESS as ALF. There are case reports of influenza vaccine triggering DRESS. In our case vaccine initially appear to be responsible for ALF, but on review was likely a bystander since mRNA vaccine does not have viral particles like influenza vaccine. Hence this case also highlights the importance of detailed history and complete lab evaluation before correlating organ injury to new mRNA COVID vaccine.

Sex Differences in Primary HIV Infection: Revisiting the Role of TLR7-Driven Type 1 IFN Production by Plasmacytoid Dendritic Cells in Women.

Plasmacytoid dendritic cells (pDCs) produce type I interferon (IFN-I) during HIV-1 infection in response to TLR7 stimulation. However, IFN-I-signaling has been shown to play opposite effects in HIV-1 and SIV infection. TLR7-driven type I interferon production in pDCs is higher in women than in men due to the cell-intrinsic actions of estrogen and X-chromosome complement. Indeed, TLR7 is encoded on the X-chromosome, and the TLR7 gene escapes the X-chromosome inactivation in immune cells of women which express significantly higher levels of TLR7 protein than male cells. Following HIV infection, women have a lower viremia during acute infection and exhibit stronger antiviral responses than men, which has been attributed to the increased capacity of female pDCs to produce IFN-α upon TLR7-stimulation. However, a deleterious functional impact of an excessive TLR7 response on acute viremia in women has been recently revealed by the analysis of the frequent rs179008 c.32A>T SNP of TLR7. This SNP was identified as a sex-specific protein abundance quantitative trait locus (pQTL) causing a difference in the TLR7 protein dosage and effector function in females only. T allele expression was associated with a lower TLR7 protein synthesis, blunted production of IFN-α by pDCs upon TLR7 stimulation, and an unexpectedly lower viral load during primary HIV-1 infection in women. In the present review, the author will revisit the role of TLR7-driven pDC innate function in the context of HIV-1 infection to discuss at what stage of primary HIV-1 infection the TLR7 rs179008 T allele is likely to be protective in women.

N130, N175 and N207 are N-linked glycosylation sites of duck Tembusu virus NS1 that are important for viral multiplication, viremia and virulence in ducklings

Duck Tembusu virus (DTMUV) is an emerging mosquito-borne flavivirus that has caused acute egg-drop syndrome in egg-laying ducks. DTMUV nonstructural protein 1 (NS1) contains three potential predicted N-linked glycosylation sites at residues 130, 175 and 207. In this study, we found that mutations at these sites affect the molecular weight of recombinant NS1, as assessed by western blot assays; however, the mutations do not affect their subcellular localization in the cytoplasm, as assessed by colocalization assays. Four recombinant viruses substituting the asparagine (N) residues at N130, N175, N207 or N130/N175/N207 of NS1 with alanine (A) residues were generated using rDTMUV-i, an infectious cDNA clone of the DTMUV CQW1 strain. Deglycosylation assays of the mutant virus NS1 were performed using endoglycosidases Endo H or PNGase F treatment in both mammalian and avian cells. The NS1-WT, NS1-N130A, NS1-N175A and NS1-N207A showed a shift in migration to 37 kDa after digestion with both endoglycosidases, which further confirmed that N130, N175 and N207 were the glycosylation sites of DTMUV NS1. Compared to the parental rDTMUV, the single mutants impaired viral multiplication in vitro, while the nonglycosylated virus rDTMUV-NS1-N130A/N175A/N207A showed a 5-fold to 178-fold decrease in viral titers and smaller plaque sizes. Notably, all mutant viruses were still highly virulent to duck embryos, but the embryos inoculated with rDTMUV-NS1-N130A/N175A/N207A started to die on the fourth day, which exhibited a prolonged time to death compared to that of rDTMUV. Moreover, rDTMUV-NS1-N130A/N175A/N207A was attenuated in vivo, showing no mortality and producing significantly lower viral titers in heart, spleen, kidney, brain and thymus as well as 2-fold to 3-fold lower viremia at 3 and 5 days post infection. Overall, our results indicated that N130, N175 and N207 are N-linked glycosylation sites of DTMUV NS1, which play crucial roles in viral multiplication, viremia and virulence in vitro and in vivo.

Efficacy of a live attenuated highly pathogenic PRRSV vaccine against a NADC30-like strain challenge: implications for ADE of PRRSV

BackgroundPorcine reproductive and respiratory syndrome virus (PRRSV) infection can cause severe reproductive failure in sows and respiratory distress in pigs of all ages, leading to major economic losses. To date, there are still no effective strategies to prevent and control PRRSV. Antibody-dependent enhancement (ADE), a phenomenon in which preexisting non-neutralizing antibodies or sub-neutralizing antibodies facilitate virus entry and replication, may be a significant obstacle in the development of effective vaccines for many viruses, including PRRSV. However, the contribution of ADE to PRRSV infection remains controversial, especially in vivo. Whether attenuated PRRSV vaccines prevent or worsen subsequent disease in pigs infected by novel PRRSV strains requires more research. In the present study, in vivo experiments were conducted to evaluate ADE under different immune statuses, which were produced by waiting different lengths of time after vaccination with a commercially available attenuated highly pathogenic PRRSV (HP-PRRSV) vaccine (JXA1-R) before challenging the pigs with a novel heterologous NADC30-like strain.ResultsPiglets that were vaccinated before being challenged with PRRSV exhibited lower mortality rates, lower body temperatures, higher bodyweight gain, and lower viremia. These results demonstrate that vaccination with JXA1-R alleviated the clinical signs of PRRSV infection in all vaccinated groups.ConclusionsThe obtained data indicate that the attenuated vaccine test here provided partial protection against the NADC30-like strain HNhx. No signs of enhanced PRRSV infection were observed under the applied experimental conditions. Our results provide some insight into the molecular mechanisms underlying vaccine-induced protection or enhancement in PRRSV.

Ubiquitous expression of HBsAg from integrated HBV DNA in patients with low viral load

Loss of serum HBsAg is a hallmark of spontaneous and therapy induced resolution of HBV infection, since it generally reflects a profound decrease in viral replication. However, integrated HBV DNA can contribute to HBsAg expression independent of viral replication. The relative contributions of these sources of HBsAg are not well understood. Specifically, it is not known whether actively transcribed HBV integration could spread throughout the entire liver. The relative distribution of HBsAg and HBV RNA in liver biopsy tissue from HBeAg-negative (HBe-) patients was analyzed by immunohistochemistry and in situ hybridization (ISH), respectively. Frozen biopsy tissue was used for molecular analysis of intrahepatic viral RNA, virus-host chimeric transcripts and viral DNA. Immunohistochemistry and ISH analysis revealed HBsAg and HBV RNA positivity in virtually all hepatocytes in the liver of some HBe- patients despite very low viremia. Reverse transcription quantitative PCR and RNA-sequencing analysis confirmed high expression levels of HBV envelope-encoding RNAs. However, the amount of viral transcriptional template (covalently closed circular (ccc)DNA) was too low to support this ubiquitous HBV RNA expression. In contrast, levels of total cellular HBV DNA were consistent with ubiquitous HBV integration. Finally, RNA-sequencing revealed the presence of many HBV-host chimeric transcripts with the potential for HBsAg expression. Transcriptionally active HBV integration can extend to the entire liver in some HBe- patients. This can lead to ubiquitous HBsAg expression independent of HBV replication. In such patients, HBsAg is probably not a clinically useful surrogate marker for viral resolution or functional cure. Loss of serum hepatitis B surface antigen (HBsAg) indicates resolution of HBV infection. However, integrated HBV DNA can contribute to HBsAg production independently of viral replication. We investigated the extent of HBsAg-producing viral integration in the livers of patients with low serum viral loads. Our findings suggest that transcriptionally active HBV integration can extend to the entire liver in some patients, questioning the clinical utility of HBsAg as a surrogate marker for viral replication.

HIV‐Associated Hypertension is TNFα‐Dependent and Involves Increased Vascular Nox1 Expression in Mice

HIV is a major global public health issue which has claimed more than 37 million lives so far. While combination antiretroviral therapies (cART) have significantly increased life expectancy, 35% of all treated HIV patients are diagnosed with hypertension. While cART treatment suppresses viral replication and further progression of the disease to AIDS, viral proteins are still present at low concentrations leading to the present clinical question of whether hypertension is the result of these viral proteins, cART regimen, or a combination of the two. We hypothesize that HIV-associated hypertension involves inflammatory response to viral proteins as well as increases in TNFα production and vascular NADPH Oxidase (Nox) 1 expression. To test this hypothesis, we utilized a transgenic mouse model (Tg26) which ubiquitously expresses seven of the nine viral proteins under the viral long terminal repeat promoter. Using quantitative RT-PCR analysis, high viral mRNA concentrations were found in lymphoid organs including the spleen, intraperitoneal immune cells, and lymph nodes but absent in the vasculature, therefore providing a mouse model mimicking clinical human pathology. Blood Pressure measurements using radio telemetry revealed that viral infection elevated mean arterial pressure in both male (WT=112.3+/-1.3 vs. Tg26=121.9+/-4.0) and female (WT=110.6+/-3.01 vs. Tg26=120.3+/-6.0mmHg) mice. Viral infection also increased systolic and diastolic blood pressure and heart rate with conserved diurnal variation. Measurement of aortic reactivity using wire myography revealed impaired endothelial relaxation (male: p<0.05/female p<0.05) to acetylcholine but intact vascular response to sodium Nitroprusside (SNP) and conserved vascular constriction to KCl and phenylephrine. Remarkably, transplant of bone marrow (BM) from Tg26 mice into WT impaired endothelial function (p<0.05) while transplant of BM from WT to Tg26 mice restored endothelial function. A multiplex cytokine panel found elevated levels of the pro-inflammatory cytokine TNFα in the plasma (p<0.05) and RT-qPCR analysis of the aorta (p<0.05) and intraperitoneal immune cells (p<0.05) also yielded increased TNFα levels. Treatment with the sTNFα inhibitor, etanercept, lowered MAP and restored endothelial function in male mice. Quantification of aortic Noxes (1,2, and 4) revealed increases in Nox1 expression (p<0.05). remarkably, selective inhibition of Nox1 via GKT771 restored endothelial dependent relaxation in both Tg26 and Tg26àWT transplanted mice. Analysis of multiple immune cell markers in the aorta via RT-qPCR found increased mRNA levels of the T-cell marker GATA3 (p<0.05). Taken together, these results support the hypothesis that HIV associated hypertension at levels of low viremia and independent of cART involves bone-derived immune cells, is TNFα dependent and involves increased vascular Nox1 expression.

Evolutionary Analysis of Pre-S/S Mutations in HBeAg-Negative Chronic Hepatitis B With HBsAg < 100 IU/ml.

Background: Hepatitis B surface antigen (HBsAg) and viral load are important clinical indicators for antiviral therapy. Few studies have evaluated viral sequence biomarkers predicting the risk of hepatocellular carcinoma (HCC) in the stage, which show a low serological response (HBsAg < 100 IU/ml) and high viral levels (HBV DNA > 2,000 IU/ml). This study aims to determine the trend of the biological prevalence within the pre-S/S regions of special model of inactive CHB infection.Methods: We used Sanger sequencing, quantitative HBV serology (HBeAg and HBsAg), and liver function index to identify whether HBV genome sequences are associated with long-term risk of further HCC progression in special inactive CHB infection.Results: HBV sequencing analysis of 28 CHB patients with special infectious pattern showed higher genetic diversity among four opening reading frames (ORFs) (p < 0.001). However, dN/dS ratios of HBsAg and pre-C/C regions in the experimental group showed no significantly different from those in the HCC group (p = 0.06), while significantly lower in polymerase and HBxAg regions of the experimental group (p < 0.001). In addition, seven positively selected sites were identified in pre-S1, five in pre-S2, and four in S, in which five sites (128H/135Q/135R/139L/141P) were among “α” determinant.Conclusions: These mutations in the pre-S/S region might be associated with the HCC phenotype of low HBsAg expression, with the P region possibly impacting high viral loads. Increased viral diversity across the HBV genome is also associated with low levels of HBsAg. The cumulative evolutionary changes in the HBV pre-S/S regions shows that facilitate immune evasion should be monitored individually. Due to the similarity of evolutionary characteristics in HCC, low serological responses and high viremia may be associated with the risk of further disease progression.

BK Virus Associated Nephropathy (BKVAN) in a Lung Transplant Recipient in the Setting of Augmented Immunosuppression

Introduction Acute kidney injury (AKI) and chronic kidney disease (CKD) are common amongst lung transplant recipients due to calcineurin inhibitor (CNI) use. We describe a case of acute BK virus associated nephropathy (BKVAN) in a lung transplant recipient with baseline CKD stage 4. Case Report A 73-year-old male status post right single lung transplant eight years prior for tobacco-induced emphysema presented for admission for acute cellular rejection (ACR). He was treated with methylprednisolone 10 mg/kg x three days per protocol. His renal function was within normal range pre-transplant, but had gradually progressed to CKD 4 with a new baseline creatinine of 2.4 at time of admission. Progressive CKD was attributed to CNIs. He had been placed on a CNI sparing regimen with everolimus more than one year prior to index admission with continued progression of renal dysfunction. Upon initiation of methylprednisolone, creatinine began to rise and eventually peaked to 4.3. UA showed trace protein but was otherwise bland, urine microscopy with muddy brown granular casts and renal tubular epithelial (RTE) cells. Renal ultrasound was poor quality showing possible small right kidney, left kidney not imaged. As part of his work-up, a BK virus PCR from his urine was sent and positive, with greater than 162 million IU/mL: serum BK PCR returned at 146,000 IU/mL. Microscopic urine analysis demonstrated RTE cells consistent with decoy cells, supportive of viral injury. A kidney biopsy was considered, however not performed because of chronic anticoagulation for a recent history of venous thromboembolism. Over the next several days, creatinine decreased minimally to 3.76. Patient was discharged home with outpatient nephrology follow up and had serial serum BK PCR tests for disease monitoring.In the setting of declining pulmonary function testing and ACR, we were unable to decrease immunosuppression without risking further deterioration of the lung allograft. Summary To our knowledge, this is the ninth reported case of BKVAN after lung transplant. BK viremia and BKVAN are likely an under-diagnosed etiology of CKD and AKI in the lung transplant population. We speculate that our patient had undiagnosed low level BK viremia that was affecting his renal function chronically, but when treated with high dose steroids, led to an acute BK nephropathy.