Early Viremia Research Articles

BK polyomavirus viremia and antibody responses of pediatric kidney transplant recipients in Finland.

BKPyV is an important cause of premature graft failure after KT. Most clinical studies describe BKPyV infection in adult KT patients. We studied the prevalence of post-transplant BKPyV viremia, serology, and graft function in pediatric KT recipients. Forty-six pediatric patients transplanted between 2009 and 2014 were followed up for BKPyV DNAemia by plasma PCR for median 2.3 (range: 1-6) years. BKPyV-specific antibodies were retrospectively analyzed using virus-like particle ELISA. GFR was measured annually by 51 Cr-EDTA clearance, and serum samples were screened for DSAs by Luminex assay. BKPyV viremia was demonstrated in nine patients at a median of 6months post-KT. Early BKPyV viremia at 3months post-KT associated with decreased concomitant GFR and tendency for decreased subsequent graft function. Three of nine patients with BKPyV viremia developed DSA, all against class II antigens. PyVAN developed to four patients and responded to judicious reduction in IS. One graft was lost later due to ABMR. BKPyV-IgG was found in 18 of 31 patients (58%) tested at transplantation, and seven recipients seroconverted after transplantation with a significant increase in IgG levels with IgM. Finally, BKPyV-IgG was detectable in 31 of 40 patients (78%) at the end of the study. Post-transplant BKPyV viremia in pediatric KT patients may alter graft function and contribute to progression of chronic allograft injury. BKPyV-IgG predicts past exposure. Low or absent BKPyV-specific antibody levels were seen pretransplant in 42% of tested patients, but were not predictive of prolonged replication or poor outcome.

Early Post-Transplant Torquetenovirus Viremia Predicts Cytomegalovirus Reactivations In Solid Organ Transplant Recipients

Monitoring the human virome has been recently suggested as a promising and novel area of research for identifying new biomarkers which would help physicians in the management of transplant patients. Imbalance of the immune system in transplant recipients has a significant impact on replication of Torquetenovirus (TTV), the most representative and abundant virus of human virome. TTV kinetic was studied by real-time PCR in 280 liver or kidney transplant recipients who underwent different drug regimens to maintain immunosuppression. During one-year post-transplant follow-up, TTV viremia fluctuated irrespective of transplanted organ type but consistent with the immunosuppression regimen. TTV kinetic in patients who manifested cytomegalovirus (CMV) reactivation within the first four months post-transplant differed from that observed in patients who did not experience CMV complications. Importantly, plasma TTV load measured between day 0 and 10 post-transplant was significantly higher in CMV DNA positive than in CMV DNA negative patients. TTV viremia above 3.45 log DNA copies/ml within the first 10 days post-transplant correlates with higher propensity to CMV reactivation following transplantation. This study provides further evidence for using early post-transplant TTV viremia to predict CMV reactivation in liver or kidney transplant recipients.

Impact of CMV and EBV on Immune Recovery After Allogeneic Hematopoietic Cell Transplantation in Children

Immune recovery is a key factor in the management of patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT). This study analyzed the factors contributing to immune reconstitution after allo-HSCT. Overall, 65 children with malignant or non-malignant diseases were included in multivariate analyses. The following factors contributed to a faster immune recovery: peripheral blood as a stem cell source and reactivation of CMV infection for CD3+ and CD4+ lymphocyte subpopulations; reactivation of CMV infection for CD8+ subset; donor EBV-IgG+ and no EBV reactivation for CD19 lymphocytes; recipient age below 10 years and peripheral blood as a stem cell source for NK cells. For CD2 and CD4/CD8 ratio no factor was significant in multivariate analysis. Patients receiving a graft from an EBV-IgG-positive donor and not having early EBV post-transplant viremia show faster recovery of the B-cells, while patients with early CMV-DNA-emia have a better re-establishment of T-cell subsets.

CMV specific T cell immunity predicts early viremia after liver transplantation

BackgroundCytomegalovirus (CMV) infection is one of the most important factors affecting liver transplant with direct and indirect effects. However, CMV disease after transplant remains poorly predicted. ObjectiveIn this study, preoperative CMV-specific cell-mediated immunity was evaluated in recipients of liver transplant in Korea, where most people are seropositive. MethodsA total of 32 patients were enrolled in a prospective study, and blood samples were collected before liver transplant to determine CMV-specific cell-mediated immunity. Testing using ELiSpot IFN-γ (CMVspot) and CMV serology were performed simultaneously. ResultsCMVspot results showed that 30 recipients had CMV-specific cell-mediated immunity, of which 29 were positive for phosphoprotein 65 and 14 for immediate early protein 1 (IE-1). All patients were positive for CMV IgG before transplantation, and 17 patients had a CMV viremia episode after transplantation. CMVspot showed 100% specificity and positive predictive value, and 11.76% sensitivity to predict CMV viremia. Patients with positive or borderline results for IE-1 did not show viremia two months after transplantation (p = .041). ConclusionCMVspot may be helpful in establishing a treatment strategy that includes regular monitoring for risk stratification of CMV reactivation.

Expression profiles of host immune response-related genes against HEV genotype 3 and genotype 1 infections in rhesus macaques.

Hepatitis E virus (HEV) genotype (gt) 3 infection is food-borne causing sporadic infections in older individuals and gt1 infection is waterborne, often causing epidemics affecting primarily young adults. Although HEV infection causes self-limited disease, gt3 induces chronic infection in immunocompromised individuals. Hepatic host gene expression against gt3 infection remains unknown. Host gene expression profiles for HEV gt1 (n=3) and gt3 (n=7) infections were analysed in the livers of experimentally infected rhesus macaques. HEV RNA was detected from 2 to 24days after inoculation (DAI) in stool and serum, elevated alanine aminotransferase (ALT) activity was detected from 7 to 31 DAI, and anti-HEV antibody became detectable between 12 and 42 DAI. All 10 animals cleared the infection between 34 and 68 DAI. We found that 24%, 48% and 41% of hepatic immune response genes against gt3 infection were upregulated during the early, peak and decline phases of HEV RNA replication. For gt1 infection, 25% of hepatic immune response-related genes were downregulated during early viremia, but 6%, 34% and 37% of genes were upregulated at the early, peak and during decline of HEV RNA replication, respectively. Our study demonstrated distinct differences in the expression profiles of host immune response-related genes of HEV gt3 and gt1 infections in experimentally infected rhesus macaques.

Evaluating the most appropriate pooling ratio for EDTA blood samples to detect Bluetongue virus using real-time RT-PCR

The control of Bluetongue virus (BTV) presents a significant challenge to European Union (EU) member states as trade restrictions are placed on animals imported from BTV-affected countries. BTV surveillance programs are costly to maintain, thus, pooling of EDTA blood samples is used to reduce costs and increase throughput. We investigated different pooling ratios (1:2, 1:5, 1:10 and 1:20) for EDTA blood samples to detect a single BTV positive animal. A published real-time RT-PCR assay (Hofmann et al., 2008) and a commercial assay (ThermoFisher VetMax™ BTV NS3 kit) were used to analyse BTV RNA extracted from pooled EDTA blood samples. The detection rate was low for the onset of infection sample (0–2 days post infection (dpi); CT 36) irrespective of the pooling ratio. Both assays could reliably detect a single BTV-positive animal at early viraemia (3–6 dpi; CT 33) when pooled, however, detection rate diminished with increasing pooling ratio. A statistical model indicated that pooling samples up to 1:20, is suitable to detect a single BTV positive animal at peak viraemia (7–12 dpi) or late infection (13–30 dpi) with a probability of detection of >80% and >94% using the Hofmann et al. (2008) and VetMAX assays, respectively. Using the assays highlighted in our study, pooling at ratios of 1:20 would be technically suitable in BTV-endemic countries for surveillance purposes. As peak viraemia occurs between 7–12 days post infection, a 1:10 pooling ratio is appropriate for post-import testing when animals are sampled within a similar time frame post-import.

Genetic variants of MICB and PLCE1 and associations with the laboratory features of dengue

BackgroundA previous genome-wide association study identified 2 susceptibility loci for severe dengue at MICB rs3132468 and PLCE1 rs3740360 and further work showed these mutations to be also associated with less severe clinical presentations. The aim of this study was to determine if these specific loci were associated with laboratory features of dengue that correlate with clinical severity with the aim of elucidating the functional basis of these genetic variants.MethodsThis was a case-only analysis of laboratory-confirmed dengue patients obtained from 2 prospective cohort studies and 1 randomised clinical trial in Vietnam (Trial registration: ISRCTN ISRCTN03147572. Registered 24th July 2012). 2742 dengue cases were successfully genotyped at MICB rs3132468 and PLCE1 rs3740360. Laboratory variables were compared between genotypes and stratified by DENV serotype.ResultsThe analysis showed no association between MICB and PLCE1 genotype and early viraemia level, platelet nadir, white cell count nadir, or maximum haematocrit in both overall analysis and in analysis stratified by serotype.DiscussionThe lack of an association between genotype and viremia level may reflect the sampling procedures within the included studies. The study findings mean that the functional basis of these mutations remains unclear.Trial registrationISRCTN ISRCTN03147572. Registered 24th July 2012.

Pathogenicity of three genetically diverse strains of PRRSV Type 1 in specific pathogen free pigs

Studies from Eastern European countries proved that porcine reproductive and respiratory syndrome virus Type 1 (PRRSV-1) harbours high genetic diversity and that genetically divergent subtypes 2–4 circulate in this area.In the present study, we compared the pathogenicity of two different PRRSV-1 subtype 2 strains and a strain representing PRRSV-1 subtype 1. Four groups of 8-week-old specific pathogen free pigs were either infected with subtype 2 strain ILI6, subtype 2 strain or BOR59, subtype 1 strain 18794, or mock inoculated.The most pronounced clinical signs were observed in pigs infected with BOR59. Pigs from both subtype 2 strain infected groups exhibited significantly elevated mean body temperatures on DPI 2 compared to the other two groups, the difference remaining significant up to DPI 13 for the BOR59 group, only. The pigs in the latter group also displayed significantly highest levels of early viremia together with the most rapid APP response.Overall, the results indicated that BOR59 strain can be considered a highly pathogenic strain, similarly to subtype 3 strains Lena and SU1-bel, while the virulence of the other subtype 2 strain ILI6 was intermediate between BOR59 and subtype 1 strain.

Mutation of the N-Terminal Region of Chikungunya Virus Capsid Protein: Implications for Vaccine Design.

ABSTRACTMosquito-transmitted chikungunya virus (CHIKV) is an arthritogenic alphavirus of the Togaviridae family responsible for frequent outbreaks of arthritic disease in humans. Capsid protein, a structural protein encoded by the CHIKV RNA genome, is able to translocate to the host cell nucleolus. In encephalitic alphaviruses, nuclear translocation induces host cell transcriptional shutoff; however, the role of capsid protein nucleolar localization in arthritogenic alphaviruses remains unclear. Using recombinant enhanced green fluorescent protein (EGFP)-tagged expression constructs and CHIKV infectious clones, we describe a nucleolar localization sequence (NoLS) in the N-terminal region of capsid protein, previously uncharacterized in CHIKV. Mutation of the NoLS by site-directed mutagenesis reduced efficiency of nuclear import of CHIKV capsid protein. In the virus, mutation of the capsid protein NoLS (CHIKV-NoLS) attenuated replication in mammalian and mosquito cells, producing a small-plaque phenotype. Attenuation of CHIKV-NoLS is likely due to disruption of the viral replication cycle downstream of viral RNA synthesis. In mice, CHIKV-NoLS infection caused no disease signs compared to wild-type CHIKV (CHIKV-WT)-infected mice; lack of disease signs correlated with significantly reduced viremia and decreased expression of proinflammatory factors. Mice immunized with CHIKV-NoLS, challenged with CHIKV-WT at 30 days postimmunization, develop no disease signs and no detectable viremia. Serum from CHIKV-NoLS-immunized mice is able to efficiently neutralize CHIKV infection in vitro. Additionally, CHIKV-NoLS-immunized mice challenged with the related alphavirus Ross River virus showed reduced early and peak viremia postchallenge, indicating a cross-protective effect. The high degree of CHIKV-NoLS attenuation may improve CHIKV antiviral and rational vaccine design.

Early and Severe Human Cytomegalovirus Deoxyribonucleic Acid (DNA) Viremia Associates With Progressive Loss of Renal Function

Early and Severe Human Cytomegalovirus Deoxyribonucleic Acid (DNA) Viremia Associates With Progressive Loss of Renal Function

Predicting Disease Severity and Viral Spread of H5N1 Influenza Virus in Ferrets in the Context of Natural Exposure Routes

Although avian H5N1 influenza virus has yet to develop the capacity for human-to-human spread, the severity of the rare cases of human infection has warranted intensive follow-up of potentially exposed individuals that may require antiviral prophylaxis. For countries where antiviral drugs are limited, the World Health Organization (WHO) has developed a risk categorization for different levels of exposure to environmental, poultry, or human sources of infection. While these take into account the infection source, they do not account for the likely mode of virus entry that the individual may have experienced from that source and how this could affect the disease outcome. Knowledge of the kinetics and spread of virus after natural routes of exposure may further inform the risk of infection, as well as the likely disease severity. Using the ferret model of H5N1 infection, we compared the commonly used but artificial inoculation method that saturates the total respiratory tract (TRT) with virus to upper respiratory tract (URT) and oral routes of delivery, those likely to be encountered by humans in nature. We show that there was no statistically significant difference in survival rate with the different routes of infection, but the disease characteristics were somewhat different. Following URT infection, viral spread to systemic organs was comparatively delayed and more focal than after TRT infection. By both routes, severe disease was associated with early viremia and central nervous system infection. After oral exposure to the virus, mild infections were common suggesting consumption of virus-contaminated liquids may be associated with seroconversion in the absence of severe disease. Risks for human H5N1 infection include direct contact with infected birds and frequenting contaminated environments. We used H5N1 ferret infection models to show that breathing in the virus was more likely to produce clinical infection than swallowing contaminated liquid. We also showed that virus could spread from the respiratory tract to the brain, which was associated with end-stage disease, and very early viremia provided a marker for this. With upper respiratory tract exposure, infection of the brain was common but hard to detect, suggesting that human neurological infections might be typically undetected at autopsy. However, viral spread to systemic sites was slower after exposure to virus by this route than when virus was additionally delivered to the lungs, providing a better therapeutic window. In addition to exposure history, early parameters of infection, such as viremia, could help prioritize antiviral treatments for patients most at risk of succumbing to infection.

Adenovirus Viremia in Adult CD34(+) Selected Hematopoietic Cell Transplant Recipients: Low Incidence and High Clinical Impact.

Adenovirus (ADV) infections after hematopoietic cell transplantation (HCT) range in severity from self-limited to fatal. We have previously reported high mortality rates in CD34(+) selected T cell-depleted (TCD) HCT recipients using symptomatic testing and culture methods for ADV detection. We report rates and outcomes of ADV viremia in 215 adult recipients of TCD HCT using the CliniMACS CD34(+) selection system. This was a prospective observational study of adults transplanted from March 21, 2012 through November 30, 2014 at Memorial Sloan-Kettering Cancer Center. TCD was performed using CliniMACS CD34(+) cell selection. Patients were monitored for ADV by whole blood PCR assay from +14 to +100 days post-transplant. ADV viremia was defined as ≥1 PCR above the lower limit of quantitation. ADV disease was defined per European Group for Blood and Marrow Transplantation guidelines. Treatment for ADV was at the clinician's discretion. Competing risk regression analyses were used to identify predictors for ADV viremia and overall survival. The median age was 55 years (range, 22 to 72); 215 patients underwent TCD. All patients received myeloablative conditioning. Eighteen patients (8% of cohort) had ADV viremia at a median onset of 57 days (interquartile range [IQR], 23 to 79) and with a median viral load at first detection of 2.6 log10 copies/mL (IQR, 2.5 to 4.0). The median maximal viral load was 4.5 log10 copies/mL (IQR, 3.5 to 5.9). No significant risk factor was identified for ADV viremia by univariate analysis. Six patients (3% of total cohort, 33% of viremic patients) developed ADV disease (3 colitis, 2 nephritis/cystitis, 1 pneumonitis). ADV viremia preceded onset of ADV disease a median of 11 days from the first positive quantitative PCR (range, +3 to +37) except in 1 patient with nephritis. Overall, 12 of 18 viremic patients (67%) received antiviral treatment (5 cidofovir only, 7 brincidofovir ± cidofovir). All patients with ADV disease were treated, and 6 patients were preemptively treated for ADV. Among the 18 viremic patients, 8 (44%) died during the study period, and, of those, 4 (22%) died of ADV. Early ADV viremia was infrequent (8%) among adult HCT recipients of CD34(+) selected allografts. Among viremic patients, rate of ADV disease was 33% and ADV attributable mortality was 22%. Further studies are needed to assess the impact of preemptive treatment with brincidofovir on improving outcomes of ADV infections in this patient population.

A Japanese encephalitis virus genotype 5 molecular clone is highly neuropathogenic in a mouse model: impact of the structural protein region on virulence.

Japanese encephalitis virus (JEV) strains can be separated into 5 genotypes (g1 to g5) based on sequence similarity. JEV g5 strains have been rarely isolated and are poorly characterized. We report here the full characterization of a g5 virus generated using a cDNA-based technology and its comparison with a widely studied g3 strain. We did not observe any major differences between those viruses when their infectious cycles were studied in various cell lines in vitro. Interestingly, the JEV g5 strain was highly pathogenic when inoculated to BALB/c mice, which are known to be largely resistant to JEV g3 infection. The study of chimeric viruses between JEV g3 and g5 showed that there was a poor viral clearance of viruses that express JEV g5 structural proteins in BALB/c mice blood, which correlated with viral invasion of the central nervous system and encephalitis. In addition, using an in vitro model of the blood-brain barrier, we were able to show that JEV g5 does not have an enhanced capacity for entering the central nervous system, compared to JEV g3. Overall, in addition to providing a first characterization of the understudied JEV g5, our work highlights the importance of sustaining an early viremia in the development of JEV encephalitis. Genotype 5 viruses are genetically and serologically distinct from other JEV genotypes and can been associated with human encephalitis, which warrants the need for their characterization. In this study, we characterized the in vitro and in vivo properties of a JEV g5 strain and showed that it was more neuropathogenic in a mouse model than a well-characterized JEV g3 strain. The enhanced virulence of JEV g5 was associated with poor viral clearance but not with enhanced crossing of the blood-brain barrier, thus providing new insights into JEV pathogenesis.

Activated CD4+CCR5+ T cells in the rectum predict increased SIV acquisition in SIVGag/Tat-vaccinated rhesus macaques

An effective T-cell-based AIDS vaccine should induce strong HIV-specific CD8(+) T cells in mucosal tissues without increasing the availability of target cells for the virus. Here, we evaluated five immunization strategies that include Human adenovirus-5 (AdHu5), Chimpanzee adenovirus-6 (AdC6) or -7 (AdC7), Vaccinia virus (VV), and DNA given by electroporation (DNA/EP), all expressing Simian immunodeficiency virus group specific antigen/transactivator of transcription (SIV(mac239Gag/Tat)). Five groups of six rhesus macaques (RMs) each were vaccinated with DNA/EP-AdC6-AdC7, VV-AdC6-AdC7, DNA/-EP-VV-AdC6, DNA/EP-VV-AdC7, or AdHu5-AdHu5-AdHu5 and were challenged repeatedly with low-dose intrarectal SIVmac239. Upon challenge, there were no significant differences among study groups in terms of virus acquisition or viral load after infection. When taken together, the immunization regimens did not protect against SIV acquisition compared with controls but did result in an ∼ 1.6-log decline in set-point viremia. Although all immunized RMs had detectable SIV-specific CD8(+) T cells in blood and rectal mucosa, we found no correlation between the number or function of these SIV-specific CD8(+) T cells and protection against SIV acquisition. Interestingly, RMs experiencing breakthrough infection showed significantly higher prechallenge levels of CD4(+)C-C chemokine receptor type 5 (CCR5)(+)HLA-DR(+) T cells in the rectal biopsies (RB) than animals that remained uninfected. In addition, among the infected RMs, the percentage of CD4(+)CCR5(+)Ki-67(+) T cells in RBs prechallenge correlated with higher early viremia. Overall, these data suggest that the levels of activated CD4(+)CCR5(+) target T cells in the rectal mucosa may predict the risk of SIV acquisition in RMs vaccinated with vectors that express SIVGag/Tat.

A Risk Score to Predict CMV Viremia within the First 100 Days after Allogeneic Stem Cell Transplantation Based on Pre-Transplant Parameters

▪Introduction:Cytomegalovirus (CMV) is a major infectious complication following allogeneic hematopoietic stem cell transplantation (HSCT). Risk of CMV infection varies between patients and individualized strategies for monitoring and therapy for CMV are needed. In this study, we attempted to establish a clinical score based on patient and transplant characteristics in order to predict the probability for early CMV viremia (CMV-V) within the first 100 days after HSCT.Methods:A total of 548 patients were evaluated after receiving HSCT between 2005 and 2012 at Princess Margaret Cancer Centre. CMV sero-negative recipients with CMV sero-negative donors (R-D-) were excluded. CMV-V was diagnosed in peripheral blood samples obtained on two occasions either by PCR (>200 IU/ml) or antigenemia testing (>2 positive cells/100000). A total of 378 patients were included into the study. Uni- and multivariable analyses were performed to identify risk factors for CMV-V. A weighted score was assigned to each factor based on the odds ratios determined by the multivariable analysis. A total score was calculated for each patient and used for assignment into one of 4 risk categories, the low risk (score 0-1), the intermediate (score 2-3), the high (score 4-5) and the very high (score 6-8).Median age for all patients was 51 years (range 17-71) and 173 (46%) were female. Matched related donors were used for two hundred fifteen patients (57%). Two hundred forty-three patients (64%) were transplanted for myeloid and 108 (29%) for lymphoid malignancies. One hundred thirteen patients (30%) were CMV sero-positive with a negative donor (R+D-) while 191 (51%) were recipient and donor CMV sero-positivity (R+D+). Graft versus host disease (GVHD) prophylaxis included CSA/MMF (n=200, 52%), and CSA/MTX (n=178, 48%). Myeloablative conditioning regimens were administered to 220 patients (58%), 158 patients (42%) were treated with a reduced intensity regimen. Three hundred-thirty seven patients (89%) received peripheral blood stem cells as a stem cell source. In vivo T cell depletion (TCD) with alemtuzumab was used in 138 (37%).Results: CMV-V occurred in 246 (64%) patients by day 100 post HSCT. The impact of patient and HSCT characteristics on the risk of CMV-V was assessed by multivariable analysis. The significant factors were CMV sero-status R+D- and R+D+, TCD, GVHD prophylaxis with MMF administration of myeloablative preparative regimens (Table 1). [Display omitted] CMV-V rates on the 4 new risk categories amounted to 93% in the very high-risk, 78% in high-risk, 41% in intermediate-risk and 11% in low-risk group (Fig 1). The risk score was also predictive for the occurrence of multiple CMV-V reactivations with rates of 71%, 45%, 19% and 4% for the very high, high, intermediate and low-risk groups, respectively.The overall survival (OS) rate at 2 years was 33%(n=56) in the very high-risk group compared to 50% in other-risk groups (n=147) (P=0.01) (Fig 2). Non-relapse mortality (NRM) was 53% in the very high-risk versus 33% in other-risk groups (P<0.001). However, there was no difference on cumulative incidence of relapse between the groups (P=0.3).The cumulative incidence of grades 1-4 acute GVHD, grades 2-4, grades 3-4 at day 120 and overall chronic GVHD at 2 years was 68%, 47%, 25% and 39% in very high-risk group versus 65%, 52%, 21% and 52% in other-risk groups, suggesting slightly lower incidence of chronic GVHD in very high-risk vs other-risk groups.Conclusion: We present a new clinical scoring system to stratify the risk of early CMV viremia after allogeneic HSCT based on patients and HSCT characteristics. Identifying the risk for each patient would facilitate decision making with respect to strategies including CMV prophylaxis, pre-emptive treatment or inclusion into clinical trials, as well directing the CMV monitoring policy post-transplant. In addition, the risk score was associated with higher risk of overall mortality and NRM in the very high-risk versus other-risk groups. [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Analysis of Early BK Viremia and Development of Antibodies to Self-Antigens (Fibronectin and Collagen IV) Following Kidney Transplantation: Effect On Long-Term Outcomes.

Background: Immune responses to tissue-restricted self-antigens (SAgs) are emerging as important risk factors for graft failure. We previously demonstrated that antibodies (Abs) to SAgs fibronectin (FN) and collagen type IV (ColIV) are associated with BK viremia and transplant (txp) glomerulopathy. The effect of early BK viremia and FN/ColIV Abs on long-term txp outcomes is unknown. We hypothesized that early BK viremia and FN/ColIV Abs portend worse long-term txp outcomes than either/no phenotype. Methods: We measured FN/ColIV Abs in plasmas from kidney txp recipients in a BK virus monitoring study (n=20). Subjects were monitored for BK viruria and/or viremia during year-1 post-txp with at least 5 years of follow-up. Non-txp patients with stage 3 chronic kidney disease (CKD, n=12) and kidney txp donors (Donors, n=12) served as controls. Using ELISA, we measured FN/ColIV Abs pre- and 1, 4, and 8 months post-txp, and in each control group. We compared trends in FN/ColIV Abs status between the BK viremic (n=10) and the BK negative group (n=10) and examined the association between BK status, FN/Col4 Abs status, and a composite outcome of acute rejection, graft failure, or death with a functioning graft. Results: Overall, 5/20 (25%) pre-txp, 5/20 (25%) post-txp, 3/12 (25%) CKD, and 0/12 Donors developed FN/ColIV Abs. By 8 months post-txp, 4/10 (40%) and 5/10 (50%) of BK viremic subjects developed FN and ColIV Abs, respectively. No BK negative subjects developed FN or ColIV Abs (p=0.03). The composite outcome was reached in 6/20 (30%) txp recipients; those who were double-positive for FN/ColIV Abs had higher risk for reaching the composite outcome than double-negative recipients, independent of BK status (Kaplan-Meier and Cox regression analysis, Figure).Figure: No Caption available.Conclusions: Abs to SAgs FN/ColIV are present in non-txp stage 3 CKD, pre- and post-kidney txp, but not healthy donors. Early immune responses to SAgs FN and ColIV are an independent predictor of long-term txp outcomes and may serve as important diagnostic and therapeutic targets in the early post-txp period.

Sequential Myeloablative Autologous Stem Cell Transplantation and Reduced Intensity Allogeneic Stem Cell Transplantation in Children, Adolescents and Young Adults with Poor Risk Refractory or Recurrent Hodgkin (HL) and Non-Hodgkin Lymphoma (NHL)

s / Biol Blood Marrow Transplant 20 (2014) S72eS90 S85 Patients were considered to have viral reactivation if CMV, EBV and ADV copies/ml were 600, 1000 and 1000, respectively. Viremia was defined as peri-AlloHCT (d0 d+14), early viremia (d15 d+98) and late viremia (d+99 d+180). From 20082012, 100 consecutive children (median age, 8 yrs; range 0.25-22 yrs; 35F/ 65M) undergoing AlloHSCT for malignant (n1⁄453) and nonmalignant (n1⁄447) disorders, were monitored. Donor sources included: matched family donor (n1⁄4 42, 42%), matched unrelated donors (n1⁄428, 28%) and unrelated cord bloods (n1⁄420, 20%). Patients were conditioned with either myeloablative [MA] (n1⁄443, 43%), reduced toxicity [RT] (n1⁄435, 35%), or reduced intensity [RI] (n1⁄422, 22%) regimens. Additionally, a total of 79 patients (79%) received serotherapy with alemtuzumab (n1⁄448, 48%) or rabbit-Anti-thymocyte globulin [r-ATG] (n1⁄431, 31%). The incidence of pre-AlloHCT viremia was 8%. The incidence of post-AlloHCT single viremia, multiple viremia and viral disease was 41, 15 and 22% respectively. The incidence of peri-AlloHCT, early and late viremia was CMV: 5%, 22.2% and 6.6%; EBV: 1%, 9.1% and 1.1%; ADV: 5%, 10.1%, and 6.6%, respectively. Viremia was noted in 36/80 (45%) of patients who received serotherapy vs. 5/20 (25%) who did not receive serotherapy (Chi-square test p1⁄40.1). Days for neutrophil, platelet engraftment, incidence of graft failure and aGVHD were not statistically significant between patients with and without viremia. We performed univariate and multivariate analysis for risk factors associated with viremia: age, sex, donor, stem cell source, graft failure, CMV risk status, alemtuzumab, r-ATG, malignant vs. non-malignant disease, MA vs. RT vs. RI regimens, absolute neutrophil and lymphocyte count at day +30. Only CMV risk status (p1⁄4.0002) and pre-AlloHCT viremia (p1⁄4 0.0095) were significant on multivariate analysis. Among patients with viremia vs. those without viremia, 1yr transplant related mortality (TRM) and all-cause mortality was 23.7% vs. 16.7 (p1⁄4.4) and 36.8% vs. 18.5% (p1⁄40.04), respectively. Among patients with viremia vs. without viremia, the median length of initial hospitalization (LOH) vs. LOH in the first 180 days were 44 days (9-144) vs. 35(19-180) (p1⁄40.02) and 91 days ( 9-165) vs. 59 days (19-180), (p1⁄40.05) respectively. Post-AlloHSCT viremia remains a significant problem and results in a significantly longer LOH. Potentially due to weekly monitoring the TRM was not significantly higher in patients with viremia.

A Direct and Indirect Comparison Meta-Analysis on the Efficacy of Cytomegalovirus Preventive Strategies in Solid Organ Transplant

Prophylactic and preemptive strategies are used to prevent cytomegalovirus (CMV) infections after solid organ transplant. We assessed the safety and efficacy of both strategies for CMV prevention. A DerSimonian and Laird random-effects model was used for pooling the data, and Q statistic and I(2) methods were used to assess statistical heterogeneity. Twenty studies (2744 patients) were selected for the direct analysis and 20 studies (2544 patients) for the indirect analysis. The odds of CMV syndrome (odds ratio [OR] = 1.10; 95% confidence interval [CI], .60-2.03; P = .757; Q = 18.55; I(2) = 51.5%) and disease (OR = 0.77; 95% CI, .41-1.47; P = .432; Q = 32.71; I(2) = 45.0%) were not significantly different between strategies. The odds of developing late-onset CMV infections were higher for the prophylactic compared to the preemptive strategy (OR = 6.21; 95% CI, 2.55-15.20; P < .0001; Q = 9.66; I(2) = 37.9%). The odds of CMV viremia were lower for prophylaxis (OR = 0.42; 95% CI, .24-.74; P = .003; Q = 48.10; I(2) = 75.1%) than preemptive therapy. No differences between strategies were noted for graft loss (OR = 0.88; 95% CI, .37-2.13; P = .779; Q = 13.03, I(2) = 38.6%), graft loss censored for death (OR = 0.73; 95% CI, .17-3.21; P = .679; Q = 4.48; I(2) = 55.3%), acute rejection (OR = 0.93; 95% CI, .70-1.24; P = .637; Q = 12.99; I(2) = 7.6%), or mortality (OR = 0.80; 95% CI, .56-1.14; P = .220; Q = 8.76; I(2) = 0%). The odds for other infections (herpes simplex virus, varicella zoster virus, bacterial and fungal infections) did not significantly differ between strategies. Leukopenia (OR = 1.97; 95% CI, 1.39-2.79; P = .0001; Q = 7.10; I(2) = 0%) and neutropenia (OR = 2.07; 95% CI, 1.13-3.78; P = .018; Q = 6.77; I(2) = 11.4%) were more frequent with prophylaxis than with the preemptive strategy. The results of direct and indirect comparisons were consistent. Prophylaxis was associated with less early posttransplant viremia, but significantly more late-onset CMV infections and side effects (leukopenia and neutropenia) than the preemptive strategy. Both preventive strategies showed similar efficacy in preventing CMV syndrome and disease, with no differences regarding rejection, graft loss, death, or opportunistic infections.

Efficient BST2 antagonism by Vpu is critical for early HIV-1 dissemination in humanized mice

BackgroundVpu is a multifunctional accessory protein that enhances the release of HIV-1 by counteracting the entrapment of nascent virions on infected cell surface mediated by BST2/Tetherin. Vpu-mediated BST2 antagonism involves physical association with BST2 and subsequent mislocalization of the restriction factor to intracellular compartments followed by SCF(β-TrCP) E3 ligase-dependent lysosomal degradation. Apart from BST2 antagonism, Vpu also induces down regulation of several immune molecules, including CD4 and SLAMF6/NTB-A, to evade host immune responses and promote viral dissemination. However, it should be noted that the multiple functions of Vpu have been studied in cell-based assays, and thus it remains unclear how Vpu influences the dynamic of HIV-1 infection in in vivo conditions.ResultsUsing a humanized mouse model of acute infection as well as CCR5-tropic HIV-1 that lack Vpu or encode WT Vpu or Vpu with mutations in the β-TrCP binding domain, we provide evidence that Vpu-mediated BST2 antagonism plays a crucial role in establishing early plasma viremia and viral dissemination. Interestingly, we also find that efficient HIV-1 release and dissemination are directly related to functional strength of Vpu in antagonizing BST2. Thus, reduced antagonism of BST2 due to β-TrCP binding domain mutations results in decreased plasma viremia and frequency of infected T cells, highlighting the importance of Vpu-mediated β-TrCP-dependent BST-2 degradation for optimal initial viral propagation.ConclusionsOverall, our findings suggest that BST2 antagonism by Vpu is critical for efficient early viral expansion and dissemination during acute infection and as such is likely to confer HIV-1 increased transmission fitness.

Association of early HIV viremia with mortality after HIV-associated lymphoma.

To examine the association between early HIV viremia and mortality after HIV-associated lymphoma. Multicenter observational cohort study. Center for AIDS Research Network of Integrated Clinical Systems cohort. HIV-infected patients with lymphoma diagnosed between 1996 and 2011, who were alive 6 months after lymphoma diagnosis and with at least two HIV RNA values during the 6 months after lymphoma diagnosis. Cumulative HIV viremia during the 6 months after lymphoma diagnosis, expressed as viremia copy-6-months. All-cause mortality between 6 months and 5 years after lymphoma diagnosis. Of 224 included patients, 183 (82%) had non-Hodgkin lymphoma (NHL) and 41 (18%) had Hodgkin lymphoma. At lymphoma diagnosis, 105 (47%) patients were on antiretroviral therapy (ART), median CD4⁺ cell count was 148 cells/μl (interquartile range 54-322), and 33% had suppressed HIV RNA (<400 copies/ml). In adjusted analyses, mortality was associated with older age [adjusted hazard ratio (AHR) 1.37 per decade increase, 95% CI 1.03-1.83], lymphoma occurrence on ART (AHR 1.63, 95% CI 1.02-2.63), lower CD4⁺ cell count (AHR 0.75 per 100 cells/μl increase, 95% CI 0.64-0.89), and higher early cumulative viremia (AHR 1.35 per log₁₀ copies × 6-months/ml, 95% CI 1.11-1.65). The detrimental effect of early cumulative viremia was consistent across patient groups defined by ART status, CD4⁺ cell count, and histology. Exposure to each additional 1-unit log₁₀ in HIV RNA throughout the 6 months after lymphoma diagnosis was associated with a 35% increase in subsequent mortality. These results suggest that early and effective ART during chemotherapy may improve survival.