Blood Viral Load Research Articles

TO006NON-INVASIVE DIAGNOSIS OF BK VIRUS-ASSOCIATED NEPHROPATHY USING URINARY PROTEOMICS IN KIDNEY ALLOGRAFT PATIENTS

Abstract Background and Aims BK virus-associated nephropathy (BKvN) is an important complication occurring after kidney transplantation. Its treatment mainly relies on lowering immune suppression. BKvN’s histological aspect can mimic T cell-mediated rejection (TCMR) and other inflammatory conditions featuring tubulitis and interstitial infiltrate. At present, the screening strategy consists of measuring urinary and blood viral loads of BKv. Upon rising BK viremia, BKvN diagnosis is established by a graft biopsy. Biopsies are invasive and are not suitable for repeated screening. Therefore, the aim of this case-control study was to establish a urinary proteome-based test for BKvN diagnosis. Method Urine was obtained from 700 allograft recipients prior to either protocol or „for cause“ biopsies during the first year of post-transplantation surveillance. Aside from normal biopsy findings (N=294), the histological diagnoses included BKvN (N=50), IFTA II-III (N=145), glomerulonephritis (N=17) and T cell-mediated, antibody-mediated, mixed or borderline rejection episodes (N=194). From all patients, relevant clinical and demographic data including Banff classification scores, HLA mismatches and the presence of donor-specific antibodies was collected at the date of sample collection and in further clinical follow-up. BKvN cases were defined as having SV40-positive immunostaining on allograft biopsy. BKvN patients were considered as cases and all other recipients were considered as controls. Patient’s urinary peptide profiles were generated using capillary electrophoresis coupled to mass spectrometry consisting of 9430 different peptides in the mass range of 0.8 to 20 kDa. Results The CE-MS peptide profiles of randomly selected 30 BKvN cases and 307 kidney allograft controls (one sample per patient) were statistically analyzed to identify the most discriminative peptide markers for BKvN. In total, there were 117 peptides detected to have significantly different urinary excretion rates between both patient groups after false discovery rate adjustment for multiple testing. Thirty-two of these peptides were selected by cross-validated variable selection to establish a Support Vector Machine-based multi-marker model. Applying the 32-peptide marker model to an independent validation cohort consisting of 20 BKvN cases and 343 controls resulted in an area under the receiver operating characteristic curve of 0.86 and a 95% confidence interval from 0.82 to 0.89 with the p-value below 0.0001 and sensitivities and specificities for BKvN diagnosis of 85 and 76 %, respectively. Most notably, distribution of the classification values (figure 1) in the different patient groups of the validation set indicated specificities of the peptide marker model for TCMR/borderline of 85% (17 of 20 true negative classifications) and for viruria/viremia of 73% (8 of 11 true negative classifications) Conclusion In conclusion, the established urinary peptide marker model might serve as a non-invasive diagnostic test for BKvN and its differentiation from TCMR and states of isolated viruria or viremia.

P0240ACQUIRED THROMBOTIC THROMBOCYTOPENIC PURPURA IN HIV POSITIVE PATIENTS SUCCESSFULLY TREATED WITH CAPLACIZUMAB: ABOUT TWO CASES

Abstract Background and Aims Acquired thrombotic thrombocytopenic purpura (aTTP) is a thrombotic microangiopathy still nowadays associated with a high risk of death. Standards of care included at first the association of plasmatic exchanges, Rituximab and steroids. The emergence of Caplacizumab, a nanobody targeting the A1 receptor of Von Willebrand Factor (VWF), significantly changed the prognosis of the disease. Thrombocytopenia is frequent in HIV positive patients, and aTTP is frequently considered. Prevalence of HIV positive in aTTP patients ranges from less than 1% in western countries, up to more than 50% in African countries. The pathophysiology still remains partially understood, leading to the development of autoantibodies targeting the ADAMTS13 metalloprotease. For now, no specific recommendations are available, and standards of care consist in treating HIV positive patient the same as other aTTP patients. We present the first description of two HIV positive patients, successfully treated with caplacizumab. Method We report there two cases of black women, respectively aged 31 (Patient 1) and 52 years old (Patient 2), both positive for HIV for several years. The first one had stopped any antiviral treatment few months ago, and had a positive blood viral load of 110764 copies/ml. Her CD4+ rate was 30/mm3. The second one was under antiviral medication, with a negative viral load and a CD4+ rate of 295/mm3. Both were admitted in our department because of low platelet levels and hemolysis, associated with inflammatory triggers. Bacteriema for Streptococcus mitis was discovered on admission in Patient 1 and Patient 2, who had a long-term follow-up for Still disease, presented with a flare-up. Results Both patients had positive anti-ADAMTS13 autoantibodies (Patient 1: titer 42 UI/ml, Patient 2: 45 UI/ml), with undetectable ADAMTS-13 activities. They were treated with plasmatic exchanges until platelets levels reached over 150 G/L, steroids 1.5 mg/kg/j, Rituximab 375 mg/m2 at day 1, 4 and 8 and finally caplacizumab 10 mg before the 2nd plasmatic exchange and every day until the ADAMTS13 activity reached over 20%. Antiviral therapy and antibiotics were initiated in Patient 1 and antiviral therapy was maintained in Patient 2. The evolution was promptly favorable with normalization of platelets levels at Day 4 in Patient 1, and Day 15 in Patient 2. Patient 1 stopped caplacizumab at Day 12 and Patient 2 at day 17, when ADAMTS 13 reached over 20%. None of them relapsed after treatment, with a respective follow-up of 4 and 2 months. Conclusion Caplacizumab seems to be a safe and efficient treatment for aTTP in HIV positive patients.

Laboratory and clinical findings and their association with viral and proviral loads in cats naturally infected with feline leukemia virus

This study was conducted to correlate clinical, laboratory, and bone marrow (BM) changes in cats naturally infected with feline leukemia virus and their association with viral loads in blood and BM and proviral loads in BM. Cats were classified into five groups based on antigenemia, clinical and/or laboratory findings and viral/proviral loads, according to a prospective study: symptomatic progressive (GI); asymptomatic progressive (GII); regressive (GIII); unclassified (GIV); or healthy (GV). |Correlations between these five groups and viral/proviral loads were evaluated. High viral and proviral loads were detected in GI and GII and viral loads were significantly associated with laboratory signs. Proviral loads detected in BM were significantly lower in GIII and GIV. GI cats were more likely to develop hematopoietic disorders than those from the other groups. Hematological and clinical disorders and disease severity are related to higher viral blood and proviral BM loads.

Detectable HIV-1 in semen in individuals with very low blood viral loads

BackgroundSeveral reports indicate that a portion (5–10%) of men living with HIV-1 intermittently shed HIV-1 RNA into seminal plasma while on long term effective antiretroviral therapy (ART). This is highly suggestive of an HIV-1 reservoir in the male genital tract. However, the status of this reservoir in men living with HIV-1 who are not under treatment is underexplored and has implications for understanding the origins and evolution of the reservoir.FindingForty-three HIV-1 positive, antiretroviral therapy naïve study participants attending a men’s health clinic were studied. Semen viral loads and blood viral loads were generally correlated, with semen viral loads generally detected in individuals with blood viral loads > 10,000 cp/ml. However, we found 1 individual with undetectable viral loads (<20cp/ml) and 2 individuals with very low blood viral load (97 and 333cp/ml), but with detectable HIV-1 in semen (485–1157 copies/semen sample). Blood viral loads in the first individual were undetectable when tested three times over the prior 5 years.ConclusionsSemen HIV-1 viral loads are usually related to blood viral loads, as we confirm. Nonetheless, this was not true in a substantial minority of individuals suggesting unexpectedly high levels of replication in the male genital tract in a few individuals, despite otherwise effective immune control. This may reflect establishment of a local reservoir of HIV-1 populations.

Genetic Diversity of Collaborative Cross Mice Controls Viral Replication, Clinical Severity, and Brain Pathology Induced by Zika Virus Infection, Independently of Oas1b.

The explosive spread of Zika virus (ZIKV) has been associated with major variations in severe disease and congenital afflictions among infected populations, suggesting an influence of host genes. We investigated how genome-wide variants could impact susceptibility to ZIKV infection in mice. We first describe that the susceptibility of Ifnar1-knockout mice is largely influenced by their genetic background. We then show that Collaborative Cross (CC) mice, which exhibit a broad genetic diversity, in which the type I interferon receptor (IFNAR) was blocked by an anti-IFNAR antibody expressed phenotypes ranging from complete resistance to severe symptoms and death, with large variations in the peak and the rate of decrease in the plasma viral load, in the brain viral load, in brain histopathology, and in the viral replication rate in infected cells. The differences in susceptibility to ZIKV between CC strains correlated with the differences in susceptibility to dengue and West Nile viruses between the strains. We identified highly susceptible and resistant mouse strains as new models to investigate the mechanisms of human ZIKV disease and other flavivirus infections. Genetic analyses revealed that phenotypic variations are driven by multiple genes with small effects, reflecting the complexity of ZIKV disease susceptibility in the human population. Notably, our results rule out the possibility of a role of the Oas1b gene in the susceptibility to ZIKV. Altogether, the findings of this study emphasize the role of host genes in the pathogeny of ZIKV infection and lay the foundation for further genetic and mechanistic studies.IMPORTANCE In recent outbreaks, ZIKV has infected millions of people and induced rare but potentially severe complications, including Guillain-Barré syndrome and encephalitis in adults. While several viral sequence variants were proposed to enhance the pathogenicity of ZIKV, the influence of host genetic variants in mediating the clinical heterogeneity remains mostly unexplored. We addressed this question using a mouse panel which models the genetic diversity of the human population and a ZIKV strain from a recent clinical isolate. Through a combination of in vitro and in vivo approaches, we demonstrate that multiple host genetic variants determine viral replication in infected cells and the clinical severity, the kinetics of blood viral load, and brain pathology in mice. We describe new mouse models expressing high degrees of susceptibility or resistance to ZIKV and to other flaviviruses. These models will facilitate the identification and mechanistic characterization of host genes that influence ZIKV pathogenesis.

Antiviral activity of phage display-selected peptides against Japanese encephalitis virus infection in vitro and in vivo

Japanese Encephalitis virus (JEV) is a zoonotic flavivirus that is the most significant etiological agent of childhood viral neurological infections. However, no specific antiviral drug is currently available to treat JEV infections. The JEV envelope (E) protein is a class II viral fusion protein that mediates host cell entry, making interference with the interaction between the E protein of JEV and its cognate receptors an attractive strategy for anti-JEV drug development. In this study, we identified a peptide derived from a phage display peptide library against the E protein of JEV, designated P1, that potentially inhibits in vitro and in vivo JEV infections. P1 inhibits JEV infection in BHK-21 cells with 50% inhibitory capacity at a concentration of 35.9 μM. The time-of-addition assay indicates that JEV replication is significantly inhibited during pre-infection and co-infection of P1 with JEV while post-infection treatments with P1 have very little impact on JEV proliferation, showing that P1 inhibits JEV infection at early stages and indicating the potential prophylactic effect of P1. We adapted an in vitro BiFC assay system and demonstrated that P1 interacts with JEV E proteins and blocks their entry into cells. We also evaluated the therapeutic efficacy of P1 in a lethal JEV mouse model exhibiting systemic and brain infections. Interestingly, P1 treatment protected C57BL/6 mice against mortality, markedly reduced the viral loads in blood and brain, and diminished the histopathological lesions in the brain cells. In addition to controlling systemic infection, P1 has a very low level of cytotoxicity and acts in a sequence-specific manner, as scrambled peptide sP1 does not show any antiviral activity. In conclusion, our in vitro and in vivo experimental findings show that P1 possesses antiviral activity against JEV infections, is safe to use, and has potential for further development as an antiviral treatment against JEV infections.

Blood viral load in the diagnostic workup of congenital cytomegalovirus infection

BackgroundThere is limited data on the role of cytomegalovirus (CMV) blood quantitative polymerase chain reaction (qPCR) in the diagnostic workup of congenital CMV (cCMV) infection. ObjectivesThe objective of this study was to determine if CMV blood qPCR at the time diagnosis could differentiate between symptomatic and asymptomatic infants according to the recent consensus classification. Study designRetrospective study of children diagnosed with cCMV infection at CHU Sainte-Justine, Montreal, Canada, between 2008 and 2016.Cases for whom qPCR was done at baseline (<4 weeks of age) alongside a complete diagnostic workup were included. The association between CMV blood viral load (VL) and clinical severity group was determined. The probability of having moderate to severe symptoms was assessed using univariate logistic regression analysis. ResultsForty-seven patients were included in the analysis. Median VL was significantly higher among infants with moderate to severely symptomatic disease vs. those asymptomatic or asymptomatic with isolated sensorineural hearing loss (SNHL) (13 736 vs. 1876 copies/ml, p = 0.004), infants with moderate to severe disease or asymptomatic with isolated SNHL vs. asymptomatic (17 736 vs. 1496 copies/ml, p < 0.001), and in infants with baseline neurological involvement vs. those without (17 317 vs. 2641 copies/ml, p = 0.03). Using logistic regression, an infant would have a >75 % probability of being moderate to severely symptomatic above 18 770 copies/ml, with a threshold of 100 000 copies/ml approaching a 100 % probability. ConclusionsOur baseline assessment of CMV blood VL suggests that that the level of CMV viremia correlates with symptom severity.

Prevention of viral transmission during lung transplantation with hepatitis C-viraemic donors: an open-label, single-centre, pilot trial

A substantial proportion of organ donors test positive for hepatitis C virus (HCV) infection. To date, only a few studies have evaluated the safety of using lungs from these donors for transplantation, and no direct interventions to donor organs have been done with the aim of preventing HCV transmission via organ transplantation. We aimed to assess the safety and efficacy of lung transplantation in humans from HCV-positive donors to HCV-negative recipients after application of ex-vivo lung perfusion (EVLP) plus ultraviolet C (UVC) perfusate irradiation. We did a single centre, prospective, open-label, non-randomised trial in which donor lungs from HCV-viraemic donors (HCV-positive) were transplanted into HCV-negative recipients at Toronto General Hospital, University Health Network (Toronto, ON, Canada). Donors were younger than 65 years old and tested positive for HCV by nucleic acid testing. Donors who tested positive for hepatitis B virus, HIV, human T-lymphotropic virus 1 or 2 were excluded. Recipients were on the lung transplant waiting list without significant liver disease (stage 2 fibrosis or higher were excluded) or active HCV infection. Before implantation, all HCV-positive donor lungs were treated with EVLP with or without UVC perfusate irradiation to reduce the concentration of HCV RNA and infectivity. For the first week after transplantation, patients' HCV RNA blood concentrations were measured once daily, then once per week for 12 weeks. All patients received 12 weeks of oral sofosbuvir 400 mg plus velpatasvir 100 mg, starting at least 2 weeks after transplantation. The primary endpoint was a composite of survival and HCV-free status at 6 months after transplantation in all patients who received HCV-positive lungs. Patient outcomes such as survival, time in hospital, and incidence of acute rejection were compared between those receiving HCV-positive lungs and all patients who received HCV-negative lung transplants during the study period. The study is registered with ClinicalTrials.gov, NCT03112044. From Oct 1, 2017, to Nov 1, 2018, 209 patients had a transplantation; of 27 donors who were HCV-positive and initially considered, 22 were suitable for transplantation. The remaining 187 donors were HCV-negative. Before implantation, 11 of the HCV-positive donor lungs were treated with EVLP alone and the other 11 were treated with EVLP plus UVC. Lung disease, urgency status, and positive donor-recipient HLA crossmatch were similar between the patients who received HCV-positive and HCV-negative lungs. 20 (91%) patients in the HCV-positive group developed HCV viraemia within the first week after transplantation and had sofosbuvir plus velpatasvir treatment, starting at a median of 21 days after transplantation (IQR 16·76-24·75). Donor organ treatment with EVLP plus UVC was associated with significantly lower recipient viral loads in blood within the first week after transplantation than with EVLP alone (median of 167 IU/mL [IQR 20-12 000] vs 4390 IU/mL [1170-112 000] at day 7; p=0·048) and prevented transmission in two (18%) of 11 patients. All 20 infected patients achieved negative HCV PCR within 6 weeks of treatment initiation. The primary endpoint of survival and HCV-free status at 6 months after transplantation was achieved in 19 (86%) of 22 patients in the HCV-positive group. 6-month survival was 95% in recipients receiving lungs from HCV-viraemic donors versus 94% in recipients receiving lungs from HCV-negative donors. The most common grade 3-4 adverse events in the HCV-positive group were respiratory complications (five [23%]) and infections (four [18%]). Serious adverse events requiring admission to hospital occurred in ten (45%) patients. One (5%) patient who did not develop HCV infection died at day 31 from multiorgan failure related to pseudomonas sepsis. Two patients presented with HCV relapse within 3 months after sofosbuvir plus velpatasvir completion and required retreatment. Early and intermediate clinical outcomes were not significantly different between patients receiving viraemic HCV donor lungs and HCV-negative donor lungs. Donor organ treatment with UVC perfusate irradiation during EVLP significantly decreased HCV viral loads within the first 7 days after transplantation and shows the proof-of-concept for a novel approach of minimising viral load ex vivo before transplantation, with intent of preventing donor-recipient transmission. Canadian Institutes of Health Research.

Risk Factors for Kaposi's Sarcoma-Associated Herpesvirus DNA in Blood and in Saliva in Rural Uganda.

Detectable Kaposi's sarcoma-associated herpesvirus (KSHV) DNA in blood and increased antibody titres may indicate KSHV reactivation, while the transmission of KSHV occurs via viral shedding in saliva. We investigated the risk factors for KSHV DNA detection by real-time polymerase chain reaction in blood and by viral shedding in saliva, in 878 people aged 3 to 89 years of both sexes in a rural Ugandan population cohort. Helminths were detected using microscopy and the presence of malaria parasitaemia was identified using rapid diagnostic tests. Regression modelling was used for a statistical analysis. The KSHV viral load in blood did not correlate with the viral load in saliva, suggesting separate immunological controls within each compartment. The proportions of individuals with a detectable virus in blood were 23% among children aged 3-5 years and 22% among those 6-12 years, thereafter reducing with increasing age. The proportions of individuals with a detectable virus in saliva increased from 30% in children aged 3-5 years to 45% in those aged 6-12 years, and decreased subsequently with increasing age. Overall, 29% of males shed in saliva, compared to 19% of females (P = .008). Together, these data suggest that young males may be responsible for much of the onward transmission of KSHV. Individuals with a current malaria infection had higher levels of viral DNA in their blood (P = .031), compared to uninfected individuals. This suggests that malaria may lead to KSHV reactivation, thereby increasing the transmission and pathogenicity of the virus.

Efficacy of Type 2 PRRSV vaccine against challenge with the Chinese lineage 1 (NADC30-like) PRRSVs in pigs

The objective of the present study was to determine the cross-protection of Ingelvac PRRS MLV against challenge with the new lineage 1 PRRSV emerged in China in pigs. Two lineage 1 PRRSV strains (FJZ03 and FJWQ16 originated from recombination event between NADC30 and JXA1-like strain). We found that pigs vaccinated with the vaccine were protected against challenge with the FJZ03 as shown by fewer days of clinical fever, reduced lung pathology scores, lower PRRS virus load in the blood and developed broadly neutralizing antibodies with high titers to FJZ03. In contrast, vaccine provided limited protection against challenge with FJWQ16 with higher fever, lower antibody titers, lower neutralizing antibodies and higher viral loads in blood. These results demonstrate PRRSV-MLV provides incomplete protection against new lineage 1 PRRSVs.

Disorders of the Cardiovascular System in Patients with Chronic Viral Hepatitis

Aim. To study some structural and functional parameters of the heart and the parameters of hepato-lienal blood flow in patients with chronic viral hepatitis (CVH).Material and methods. 74 patients with CVH were examined, the average age was 41 years, the disease duration – 3.6 years. The patients were divided into 2 groups: group 1 – patients with minimal biochemical activity of hepatitis (n=39); group 2 – patients with moderate hepatitis activity (n=35). The control group included 22 healthy patients. Parameters of tissue doppler echocardiography, hepato-lienal blood flow were evaluated depending on the laboratory activity of CVH.Results. The systolic velocity of the fibrous ring displacement of the tricuspid valve in patients of groups 1 and 2 was lower than in the control by 15% and 17%, respectively (p&lt;0.001). Em decreased in groups 1 and 2 in comparison with healthy individuals in the basal segment of the left ventricle lateral wall, on the mitral valve fibrous ring, in the basal segment of the interventricular septum (p&lt;0.001). The Em/Am ratio decreased in patients of groups 1 and 2 compared with healthy patients in the basal segment of the left ventricle lateral wall, in the medial segment of the interventricular septum, on fibrous ring of the tricuspid valve, in the basal and medial segments of the right ventricular lateral wall (p&lt;0.001). Isovolumic contraction and relaxation time as well as the volume index of the left atrium were increased in patients of the 1st and 2nd groups in comparison with control; more severe violations were observed in patients of the 2nd group (p&lt;0.001). In patients of both groups, acceleration of blood flow and dilation of arteries and veins in the hepato-lienal circulation system (p&lt;0.001) were found. Besides, in patients with moderate hepatitis activity there was an acceleration of blood flow in the hepatic artery in comparison with the control (p&lt;0.001).Conclusion. In patients with CVH the follow disorders were observed: decrease in the global longitudinal systolic function of the right ventricle, violation of diastolic relaxation of the ventricles, increase in the volume index of the left atrium, as well as expansion of the arteries and veins of the hepato-lienal circulation system. These violations were more pronounced in patients with a moderate laboratory activity of CVH. Correlations between cardiohemodynamic parameters, indicators of hepato-lienal blood flow and viral load were revealed.

Suppression of Active HIV-1 Infection in CD34+ Hematopoietic Humanized NSG Mice by a Combination of Combined Antiretroviral Therapy and CCR5 Targeting Drugs.

Significant progress has been made in the diagnostics and treatment of AIDS since the discovery of the human immunodeficiency virus type 1 (HIV-1) in 1983. The remarkable effectiveness of combined antiretroviral therapy (cART) is evidenced by mortality reduction, control of peripheral blood viral load, and in a nearly normal quality of HIV patients' lives. Remaining obstacles in treatment and cure are drug toxicities and side effects, viral resistance, persistence of HIV-1 reservoirs on termination of cART treatment, the cost of lifelong antiretroviral therapy, and the stigma associated with taking antiretroviral drugs. As determined by plasma viral RNA and peripheral blood mononuclear cells (PBMC) proviral DNA, we show improved suppression of productive HIV infection in human CD34+ hematopoietic stem cell-engrafted NOD (nonobese diabetic)-SCID (severe combined immunodeficiency)-il2rg-/- (NSG) mice by combined treatment with cART and CCR5 targeting drugs, compared with cART alone, as well as an increased preservation of human CD4+ T cells (defined as CD45+ CD3+ CD4+ cells) and CD4+/CD8+ cell ratios in infected mice. The data also suggest a possible reduction in viral reservoirs. Our data confirm that this animal model is suitable for detection of productive HIV infection, replication, and establishment of viral reservoirs. The data also provide proof of principle for the utility of combining CCR5 targeting drugs, maraviroc and rapamycin, with traditional cART to improve control of viremia and reduce viral reservoirs. This study thus serves as a model for future HIV-1 studies that could lead to the clinical development of new generations of antiretroviral drugs.

Persistent primary cytomegalovirus infection in a kidney transplant recipient: Multi-drug resistant and compartmentalized infection leading to graft loss

Cytomegalovirus (CMV) is one of the most common opportunistic infections after transplantation. To prevent CMV infections, universal prophylaxis and pre-emptive therapy with ganciclovir or its prodrug valganciclovir is applied. However, prolonged antiviral therapy may result in drug-resistance emergence. We describe a case of a 43-year-old CMV-seronegative patient who underwent kidney transplantation from a CMV-seropositive donor and developed CMV disease despite valganciclovir prophylaxis. CMV viral load increased even though valgangiclovir dose was augmented and immunosuppressive therapy reduced. CMV genotyping revealed mutations in the viral UL97 protein kinase, explaining ganciclovir-resistant CMV infection. The viral load failed to respond to foscavir, cidofovir and CMV-neutralizing immunoglobulins. Kidney allograft dysfunction developed 3 months post-transplantation with a histopathologic diagnosis of CMV nephropathy and potentially concomitant T-cell mediated rejection. A transplantectomy was performed on day 164 post-transplantation since the patient had uncontrollable CMV disease associated with a circulating multidrug-resistant DNA polymerase-mutant virus. Detailed monitoring in this patient demonstrated hallmarks of complicated CMV disease: (i) relatively rapid evolution of drug-resistant CMV mutants in the setting of persistent high blood viral loads, (ii) emergence of viral drug-resistance linked to acute graft rejection, (iii) transient and, thereafter, lack of response to various anti-CMV treatments, (iv) compartmentalization and heterogeneity of CMV viral populations, (v) possible differential ability of viral mutants to cause disease in the graft, and (vi) detection of minor viral variants by next generation sequencing. Translational research platforms that provide rapid molecular genotyping for detection of CMV drug-resistance are essential in guiding CMV disease management in high-risk transplant recipients.

Lung Transplantation Using Hepatitis C Viremic Donors: An Open-Label Single Center Pilot Trial of Prevention of Viral Transmission

Background: A significant proportion of organ donors currently test positive for hepatitis C virus (HCV) infection. To date, only a few studies have evaluated the safety of using lungs from these donors for transplantation, and no direct interventions to donor organs have been performed with the aim of preventing HCV transmission via organ transplantation. Methods: We performed a single center prospective non-randomized trial where donor lungs from HCV viremic donors were transplanted into HCV negative (HCV-ve) recipients. Outcomes of study recipients were compared to patients receiving HCV-ve donors. Primary endpoints were survival and HCV status at 6 months after transplantation. Prior to implantation, all donor lungs were treated with ex vivo lung perfusion (EVLP) with (n=11) or without (n=11) ultraviolet C (UVC) perfusate irradiation to reduce HCV RNA levels and infectivity. All patients becoming viremic received 12 weeks of sofosbuvir/velpatasvir (S/V) starting at least 2 weeks after transplantation. Findings: During the 13-month study period, 22 patients were transplanted using viremic HCV donors and 187 with HCV-ve donors. Recipient age, lung disease, urgency status and positive donor-recipient HLA crossmatch were similar between the 2 groups. Post-transplant outcomes such as primary graft dysfunction grades, ICU and hospital length of stay, and survival were similar between the 2 groups. Twenty patients (91%) developed HCV viremia within the first week after transplantation and underwent S/V treatment starting at a median of 21 days after transplantation (range 14-71 days). Donor organ treatment with EVLP+UVC was associated with significantly lower recipient viral loads in blood within the first week after transplantation, and prevention of transmission in 2/11 patients. All infected patients achieved negative HCV PCR within 6 weeks of treatment initiation. Two patients presented with HCV relapse within 3 months after S/V completion requiring retreatment. Interpretation: Early and intermediate-term clinical outcomes using viremic HCV donors were similar to patients receiving HCV-ve donor lungs. Donor organ treatment using UVC perfusate irradiation during EVLP showed a significant impact in decreasing HCV viral loads within the first 7 days after transplantation. Trial Registration Number: The trial was registered at clinicaltrials.gov (NCT03112044). Funding Statement: This study was an investigator-initiated study funded by an operating grant from the Canadian Institutes of Health Research (CIHR). Gilead Sciences provided S/V (Epclusa) for all patients in the study. XVIVO perfusion (Gothenburg, Sweden) provided Steen solution for EVLP Declaration of Interests: Dr. Cypel, Waddell and Keshavjee are co-founders of Perfusix Canada, XOR Labs Toronto, and consultants for Lung Bioengineering (United Therapeutics). Ethics Approval Statement: This study was approved by the Research Ethics Board of University Health Network and subjects provided written informed consent while on the transplant waiting list prior to the offer of HCV+ve donor lungs.

The therapeutic effect of switching from tacrolimus to low-dose cyclosporine A in renal transplant recipients with BK virus nephropathy.

Background: There is no effective therapy for BK virus (BKV) nephropathy (BKVN). Cyclosporine A (CsA) has a lower immunosuppressive effect than tacrolimus. In vitro studies have shown that CsA inhibits BKV replication. The present study aimed to evaluate the effectiveness of switching from tacrolimus to low-dose CsA in renal transplant recipients with BKVN. Methods: Twenty-four patients diagnosed with BKVN between January 2015 and December 2016 were included. Tacrolimus was switched to low-dose CsA, and patients were followed for 24 months. Primary end points were BKV clearance in blood and graft. Secondary end points were urine specific gravity, serum creatinine, and graft loss. Results: The viremia in all patients cleared at a mean of 2.7 ± 2.0 months after switching to CsA. Urine specific gravity at 3 months after switching to CsA increased significantly compared with that at diagnosis (P=0.002). The timing and trend of urine specific gravity increase was consistent with the timing and trend of blood and urine viral load decrease. Repeated biopsies at a median of 11.2 months (range: 9.1–12.5 months) after switching to CsA showed that 8 patients (42.1%) were negative for BKV, and 11 patients (58.9%) had a decrease in BKV load (P<0.001). There was no statistical difference in the serum creatinine level between the time of diagnosis and 24 months of CsA therapy (P=0.963). The graft survival rate was 100%. Only two patients (8.3%) suffered from acute rejection. Conclusion: Switching from tacrolimus to low-dose CsA may be an effective therapy for BKVN.

Enhanced adherence counselling and viral load suppression in HIV seropositive patients with an initial high viral load in Harare, Zimbabwe: Operational issues.

BackgroundIn people living with HIV (PLHIV) who are on anti-retroviral therapy (ART), it is essential to identify persons with high blood viral loads (VLs) (≥1000 copies/ml), provide enhanced adherence counselling (EAC) for 3 months and assess for VL suppression (<1000 copies/ml).ObjectiveOur study objectives were to determine the proportion who had a high viral load in those people who underwent viral load testing between 1 August 2016–31 July 2017 at Wilkins Hospital, Harare, Zimbabwe. Of those with high viral load to assess; a) the proportion who enrolled for EAC, the demographic and clinical characteristics associated with enrolment for EAC and, b) the proportion who achieved viral load suppression and demographic, clinical characteristics associated with viral load suppression.DesignRetrospective cohort study using routinely collected programme data. Data was collected from PLHIV who were on ART and had a high viral load from 1 August 2016 to 31 July 2017.ResultsOf 5,573 PLHIV on ART between 1 August 2016 and 31 July 2017, 4787 (85.9%) had undergone VL testing and 646 (13.5%) had high VLs. Of these 646, only 489 (75.7%) were enrolled for EAC, of whom 444 (69%) underwent a repeat VL test at ≥ 3 months with 201 (31.2%) achieving VL suppression. The clinical characteristics that were independently associated with higher probability of VL suppression were: a) undergoing 3 sessions of EAC; b) being on 2nd line ART. Initial VL levels >5,000 copies/ml were associated with lower probability of viral suppression.ConclusionThe routine VL testing levels were high, but there were major programmatic gaps in enrolling PLHIV with high VLs into EAC and achieving VL suppression. The full potential of EAC on achieving viral load suppression has not been achieved in this setting. The reasons for these gaps need to be assessed in future research studies and addressed by suitable changes in policies/practices.

Generation of Pigs Resistant to Highly Pathogenic-Porcine Reproductive and Respiratory Syndrome Virus through Gene Editing of CD163.

Porcine reproductive and respiratory syndrome (PRRS) is a highly contagious disease and the most economically important disease of the swine industry worldwide. Highly pathogenic-PRRS virus (HP-PRRSV) is a variant of PRRSV, which caused high morbidity and mortality. Scavenger receptor CD163, which contains nine scavenger receptor cysteine-rich (SRCR) domains, is a key entry mediator for PRRSV. A previous study demonstrated that SRCR domain 5 (SRCR5), encoded by exon 7, was essential for PRRSV infection in vitro. Here, we substituted exon 7 of porcine CD163 with the corresponding exon of human CD163-like 1 (hCD163L1) using a CRISPR/Cas9 system combined with a donor vector. In CD163Mut/Mut pigs, modifying CD163 gene had no adverse effects on hemoglobin-haptoglobin (Hb-Hp) complex clearance or erythroblast growth. In vitro infection experiments showed that the CD163 mutant strongly inhibited HP-PRRSV replication by inhibiting virus uncoating and genome release. Compared to wild-type (WT) pigs in vivo, HP-PRRSV-infected CD163Mut/Mut pigs showed a substantially decreased viral load in blood and relief from PRRSV-induced fever. While all WT pigs were dead, there of four CD163Mut/Mut pigs survived and recovered at the termination of the experiment. Our data demonstrated that modifying CD163 remarkably inhibited PRRSV replication and protected pigs from HP-PRRSV infection, thus establishing a good foundation for breeding PRRSV-resistant pigs via gene editing technology.

Deletion of CD163 Exon 7 Confers Resistance to Highly Pathogenic Porcine Reproductive and Respiratory Viruses on Pigs.

Porcine reproductive and respiratory syndrome (PRRS) caused by PRRS virus (PRRSV) is a severe infectious disease in the swine industry. PRRSV infection is mediated by porcine CD163 (pCD163). Scavenger receptor cysteine-rich domain 5 coded by exon 7 of pCD163 is essential for PRRSV infection. In this study, we generated CD163 exon 7 deleted (CD163E7D) pigs using CRISPR/Cas9 mediated homologous recombination and somatic cell nuclear transfer (SCNT). The deletion of exon 7 had no adverse effects on CD163-associated functions. Pigs were further challenged with a highly pathogenic PRRSV (HP-PRRSV) strain. The CD163E7D pigs exhibited mild clinical symptoms and had decreased viral loads in blood. All CD163E7D pigs survived the viral challenge, while all the WT pigs displayed severe symptoms, and 2 out of 6 WT pigs died during the challenge. Our results demonstrated that CD163 exon 7 deletion confers resistance to HP-PRRSV infection without impairing the biological functions of CD163.

The efficacy of nelfinavir and lopinavir/ritonavir in the treatment of HIV-infected pediatric patients

Objective: to characterize the efcacy of nelfnavir and lopinavir/ritonavir in the starting regimens of antiretroviral therapy for HIV-infected pediatric patients.Materials and methods: 50 HIV-infected patients aged 24-36 months were treated with abacavir and lamivudine in combination with nelfnavir (24 children) or lopinavir/ritonavir (26 patients).Results: Using both antiretroviral therapy schemes leads to suppression of HIV replication, improvement of clinical and immunological parameters. However, the treatment with lopinavir/ritonavir revealed a signifcant positive changes of HIV blood viral load, immune status and clinical picture. With the help of mathematical modeling, the signifcance of lopinavir/ritonavir appointment as an independent predictor of effectiveness prolongation of antiretroviral therapy has been proved. As a side effect of lopinavir/ritonavir developed dyspeptic symptoms.Conclusion: Te results of the study indicate the high efcacy and safety of lopinavir/ritonavir use compared to nelfnavir in HIV-infected pediatric patients.

Favipiravir inhibits in vitro Usutu virus replication and delays disease progression in an infection model in mice

Usutu virus (USUV) is an emerging flavivirus that causes Usutu disease mainly in birds, but infection of mammals such as rodents, bats and horses has also been demonstrated. In addition, human cases (both in immunocompromised and -competent individuals) were also reported. Large outbreaks with other flaviviruses, such as West Nile virus and Zika virus, indicate that one should be vigilant for yet other outbreaks. To allow the identification of inhibitors of USUV replication, we established in vitro antiviral assays, which were validated using a small selection of known flavivirus inhibitors, including the broad-spectrum viral RNA polymerase inhibitor favipiravir (T-705). Next, an USUV infection model in AG129 (IFN-α/β and IFN-γ receptor knockout) mice was established. AG129 mice proved highly susceptible to USUV; an inoculum as low as 102 PFU (1.3 × 105 TCID50) resulted in the development of symptoms as early as 3 days post infection with viral RNA being detectable in various tissues. Treatment of mice with favipiravir (150 mg/kg/dose, BID, oral gavage) significantly reduced viral load in blood and tissues and significantly delayed virus-induced disease. This USUV mouse model is thus amenable for assessing the potential in vivo efficacy of (novel) USUV/flavivirus inhibitors.