Safety and efficacy of the oral TLR8 agonist selgantolimod in individuals with chronic hepatitis B under viral suppression.

BACKGROUND & AIMS: Selgantolimod (GS-9688) is a Toll-like receptor 8 (TLR8) agonist that suppresses HBV in vitro. In a phase II study, we evaluated the safety and efficacy of weekly selgantolimod treatment in virally suppressed individuals with chronic HBV taking oral antiviral treatment. METHODS: Forty-eight patients were randomized into two cohorts (hepatitis B e antigen [HBeAg]-positive and -negative [n = 24 each]) to receive oral selgantolimod 3 mg, 1.5 mg, or placebo (2:2:1) once weekly for 24 weeks while maintaining oral antivirals. The primary efficacy endpoint was the percentage of patients with a ≥1 log10 IU/ml decline in hepatitis B surface antigen (HBsAg) from baseline to week 24. Post-treatment, patients continued on oral antivirals for 24 weeks. RESULTS: The primary endpoint was reached by one participant, who was HBeAg-negative and received selgantolimod 1.5 mg. In contrast with placebo-treated patients (n = 9), only selgantolimod-treated patients (n = 39 total) had HBsAg declines greater than 0.1 log10 IU/ml at weeks 24 (18%, 7/39) and 48 (26%, 10/39), HBsAg loss (5%, 2/39 through 48 weeks), or HBeAg loss (16%, 3/19 through 48 weeks). The most common adverse events in selgantolimod-treated groups were nausea (46%), upper respiratory tract infection (23%), and vomiting (23%). Gastrointestinal disorders were mostly mild and transient. Selgantolimod induced transient dose-dependent increases in serum cytokines, including IL-12p40, IFN-γ, and IL-1RA, as well as rapid redistribution of some circulating immune cell subsets. CONCLUSION: Oral selgantolimod up to 3 mg once weekly for 24 weeks was generally safe and well tolerated and led to serologic changes associated with progression to durable cure in two individuals by week 48. GOV IDENTIFIER: NCT03491553. IMPACT AND IMPLICATIONS: The only robust criterion for stopping treatment in chronic hepatitis B is loss of hepatitis B surface antigen (known as functional cure), which is rare during nucleos(t)ide analogue therapy. It is likely that novel antiviral and immunomodulatory therapies will be needed to achieve finite functional cure. Selgantolimod is an oral Toll-like receptor 8 agonist that has shown antiviral activity in vitro as well as safety in a phase I clinical trial with weekly dosing. In this phase II study, selgantolimod therapy was associated with transient increases in serum cytokines, rapid redistribution of circulating immune cell subsets, modest reductions in HBsAg and HBeAg levels, and occasional loss of HBsAg (5%) and HBeAg (16%) among participants with chronic hepatitis B on nucleos(t)ide analogue therapy with viral suppression. Our results support continued development of selgantolimod as a component of a future hepatitis B cure regimen.

Hepatitis B virus haplotype number at baseline is a predictive marker of functional cure during antiviral therapy for patients with genotypes A and D HBeAg-positive chronic hepatitis B.

BACKGROUNDS AND AIMS: We investigated associations between hepatitis B virus (HBV) genome-length haplotype number (HN) at baseline in subjects with HBeAg-positive chronic hepatitis B (CHB), and the likelihood of achieving functional cure during direct-acting antiviral therapy METHOD: We analysed 86 HBeAg-positive baseline samples from patients with HBV genotypes A and D who were enrolled in a Phase II trial of tenofovir disoproxil fumarate (TDF) to determine if HN was a biomarker of HBsAg loss during therapy. Findings were validated using baseline samples from 181 patients with HBV genotypes A and D from an independent clinical trial utilising TDF or tenofovir alafenamide therapy in HBeAg-positive CHB. RESULTS: In the HBeAg-positive test cohort, patients with genotypes A or D and ≤2 haplotypes had a minimum of 21-fold higher likelihood of achieving HBsAg loss on TDF. Baseline HN (p < 0.0001) was a stronger predictor of HBsAg loss on therapy than HBsAg titre (p = 0.03), HBeAg titre (p = 0.0002), or the presence of HBV basal core promoter (A1762T, p = 0.0379 and G1764A, p = 0.0176) or G1896A precore mutations (p = 0.0218). This finding was validated in the independent validation cohort. HN was statistically higher in patients with HBV genotypes B or C infection compared to genotypes A and D. CONCLUSION: Baseline HN ≤2 predicts which patients with HBV genotypes A or D will more likely progress to functional cure on current direct-acting antiviral therapy, with greater accuracy than current biomarkers including baseline HBsAg and HBeAg titre.

Oral Selective TLR8 Agonist Selgantolimod Induces Multiple Immune Cell Responses in Humans.

TLR8 agonists have the potential for use as immunomodulatory components in therapeutic modalities for viral infections such as chronic HBV (CHB) and HIV. In this study, using peripheral blood samples from a phase 1a clinical trial, we examined the acute effects of a single oral administration of a selective TLR8 agonist on immune cell phenotypes. Administration of the TLR8 agonist selgantolimod (SLGN) in healthy individuals resulted in alteration in frequencies of peripheral blood monocytes, pDCs, mDCs and MAIT cells. Frequencies of mDCs and lymphoid cells significantly reduced after 8 h of SLGN administration, whereas pDC frequencies significantly increased, with changes possibly reflecting migration of different cell types between peripheral and tissue compartments in response to the agonist. Myeloid cell activation was evident by an upregulated expression of co-stimulatory molecules CD40 and CD86 accompanied by the production of IL-6 and IL-18 from these cells. Concomitantly, there was induction of the early activation marker CD69 on innate and adaptive lymphoid cells, including MAIT and NK cell subsets. Further, these activated lymphoid cells had enhanced expression of the effector molecules granzyme B and perforin. Microarray analysis of isolated lymphocytes and monocytes from baseline and post-SLGN treatment revealed changes in expression of genes involved in cellular response to cytokine stimulus, innate immune response, myeloid cell differentiation and antigen receptor-mediated signaling pathway. In a preliminary analysis of samples from CHB patients treated with selgantolimod, activation of innate and adaptive lymphocytes was evident. In conclusion, this first in-human study shows that selgantolimod administration in humans results in activation of multiple immune cell responses with antiviral potential.

Follicular Helper T (TFH) Cell Targeting by TLR8 Signaling For Improving HBsAg-Specific B Cell Response In Chronic Hepatitis B Patients.

Identifying signaling pathways that induce B cell response can aid functional cure strategies for chronic hepatitis B infection (CHB). TLR8 activation with ssRNA was shown to enhance follicular helper T cell (TFH) function leading to improved B cell responses in vitro. We investigated whether this mechanism can rescue an exhausted immune response in CHB infection. Effect of TLR8 agonism on supporting cytokines and TFH and B cells were evaluated using ex vivo and in vitro assays. The ability of an oral TLR8 agonist to promote TFH and B cell response was tested in samples from phase 1b clinical trial. TLR8 agonism induced TFH polarizing cytokine IL-12 in monocytes. Treatment of peripheral blood mononuclear cells (PBMCs) from CHB patients with TLR8 agonists induced cytokine IL-21 by TFH cells with enhanced IL-21+BCL-6+ and ICOS+BCL-6+ co-expression. Mechanistically, incubation of isolated naïve CD4+ T cells with TLR8 triggered monocytes resulted in their differentiation into IL-21+ICOS+BCL-6+ TFH in an IL-12 dependent manner. Furthermore, co-culture of these IL-21 producing TFH with autologous naïve B cells led to enhanced memory (CD19+CD27+) and plasma B cell generation (CD19+CD27++CD38+) and IgG production. Importantly, in TFH from CHB patients treated with an oral TLR8 agonist, HBsAg-specific BCL-6, ICOS, IL-21 and CD40L expression and rescue of defective activation induced marker (AIM) response along with partial restoration of HBsAg-specific B cell ELISPOT response was evident. TLR8 agonism can thus enhance HBV-specific B cell responses in CHB patients by improving monocyte-mediated TFH function and may play a role in achieving HBV functional cure.

Antiviral kinetics of tenofovir alafenamide and tenofovir disoproxil fumarate over 24 weeks in women of childbearing potential with chronic HBV.

BACKGROUND/PURPOSE: Use of tenofovir disoproxil fumarate (TDF) improves patient outcomes in preventing mother-to-child transmission (pMTCT) of the hepatitis B virus (HBV) in mothers with chronic HBV and high viral loads. Given the lack of data for tenofovir alafenamide (TAF) in pMTCT, rates of early viral suppression with TAF and TDF were evaluated in women of childbearing potential (WOCBP) participating in 2 randomized, double-blind, Phase 3 studies in chronic HBV. METHODS: In a patient subset meeting WOCBP criteria and with baseline HBV DNA >200,000 IU/mL, rates of viral suppression with TAF or TDF in achieving the target of HBV DNA <200,000 IU/mL at weeks 12 and 24 were assessed. Multivariate logistic regression was used to identify factors predictive of failure to suppress HBV DNA to the target level. RESULTS: In 275 of 1298 (21%) patients meeting WOCBP criteria with high viral load, 93% and 96% had HBV DNA <200,000 IU/mL at weeks 12 and 24, respectively. Results for TAF (n = 194) vs TDF (n = 81) treatment were similar at weeks 12 and 24 (94% vs. 90% and 97% vs. 93%), respectively. High baseline HBV DNA level, genotype D infection, and prior interferon (week 24 only) were predictive of failure to achieve the target level. Both treatments were well tolerated with TAF showing less impact on renal and bone parameters. CONCLUSIONS: In WOCBP with high VL, no differences were found between TAF and TDF in reducing HBV DNA to levels associated with lower transmission risk. These data support ongoing studies of TAF for pMTCT.

Safety, Pharmacokinetics, and Pharmacodynamics of the Oral TLR8 Agonist Selgantolimod in Chronic Hepatitis B.

BACKGROUND AND AIMS: In patients with chronic hepatitis B (CHB) infection, activation of toll-like receptor 8 may induce antiviral immunity and drive functional cure. Selgantolimod, a toll-like receptor 8 agonist, was evaluated in patients with CHB who were virally suppressed on oral antiviral treatment or viremic and not on oral antiviral treatment. APPROACH AND RESULTS: In this phase 1b study, patients were randomized 4:1 to receive either selgantolimod or placebo once weekly. Virally suppressed patients received either 1.5 mg (for 2 weeks) or 3 mg (for 2 weeks or 4 weeks). Viremic patients received 3 mg for 2 weeks. The primary endpoint was safety, as assessed by adverse events (AEs), laboratory abnormalities, and vital sign examination. Pharmacokinetic and pharmacodynamic parameters were assessed by plasma analysis. A total of 38 patients (28 virally suppressed, 10 viremic) were enrolled from six sites in Australia, New Zealand, and South Korea. Twenty patients (53%) experienced an AE and 32 (84%) had laboratory abnormalities, all of which were mild or moderate in severity. The most common AEs were headache (32%), nausea (24%), and dizziness (13%). With a half-life of 5 hours, no accumulation of selgantolimod was observed with multiple dosing. Selgantolimod induced transient dose-dependent increases in serum cytokines, including IL-12p40 and IL-1RA, which are important for the expansion and activity of multiple T- cell subsets and innate immunity. CONCLUSION: Selgantolimod was safe and well-tolerated in virally suppressed and viremic patients with CHB and elicited cytokine responses consistent with target engagement. Further studies with longer durations of selgantolimod treatment are required to evaluate efficacy.

Compassionate Use of Remdesivir in Pregnant Women With Severe Coronavirus Disease 2019.

BACKGROUND: Remdesivir is efficacious for severe coronavirus disease 2019 (COVID-19) in adults, but data in pregnant women are limited. We describe outcomes in the first 86 pregnant women with severe COVID-19 who were treated with remdesivir. METHODS: The reported data span 21 March to 16 June 2020 for hospitalized pregnant women with polymerase chain reaction-confirmed severe acute respiratory syndrome coronavirus 2 infection and room air oxygen saturation ≤94% whose clinicians requested remdesivir through the compassionate use program. The intended remdesivir treatment course was 10 days (200 mg on day 1, followed by 100 mg for days 2-10, given intravenously). RESULTS: Nineteen of 86 women delivered before their first dose and were reclassified as immediate "postpartum" (median postpartum day 1 [range, 0-3]). At baseline, 40% of pregnant women (median gestational age, 28 weeks) required invasive ventilation, in contrast to 95% of postpartum women (median gestational age at delivery 30 weeks). By day 28 of follow-up, the level of oxygen requirement decreased in 96% and 89% of pregnant and postpartum women, respectively. Among pregnant women, 93% of those on mechanical ventilation were extubated, 93% recovered, and 90% were discharged. Among postpartum women, 89% were extubated, 89% recovered, and 84% were discharged. Remdesivir was well tolerated, with a low incidence of serious adverse events (AEs) (16%). Most AEs were related to pregnancy and underlying disease; most laboratory abnormalities were grade 1 or 2. There was 1 maternal death attributed to underlying disease and no neonatal deaths. CONCLUSIONS: Among 86 pregnant and postpartum women with severe COVID-19 who received compassionate-use remdesivir, recovery rates were high, with a low rate of serious AEs.

Metagenomic sequencing of stool samples in Bangladeshi infants: virome association with poliovirus shedding after oral poliovirus vaccination.

The potential role of enteric viral infections and the developing infant virome in affecting immune responses to the oral poliovirus vaccine (OPV) is unknown. Here we performed viral metagenomic sequencing on 3 serially collected stool samples from 30 Bangladeshi infants following OPV vaccination and compared findings to stool samples from 16 age-matched infants in the United States (US). In 14 Bangladeshi infants, available post-vaccination serum samples were tested for polio-neutralizing antibodies. The abundance (p = 0.006) and richness (p = 0.013) of the eukaryotic virome increased with age and were higher than seen in age-matched US infants (p < 0.001). In contrast, phage diversity metrics remained stable and were similar to those in US infants. Non-poliovirus eukaryotic virus abundance (3.68 log10 vs. 2.25 log10, p = 0.002), particularly from potential viral pathogens (2.78log10 vs. 0.83log10, p = 0.002), and richness (p = 0.016) were inversely associated with poliovirus shedding. Following vaccination, 28.6% of 14 infants tested developed neutralizing antibodies to all three Sabin types and also exhibited higher rates of poliovirus shedding (p = 0.020). No vaccine-derived poliovirus variants were detected. These results reveal an inverse association between eukaryotic virome abundance and poliovirus shedding. Overall gut virome ecology and concurrent viral infections may impact oral vaccine responsiveness in Bangladeshi infants.

Safety, pharmacokinetics and pharmacodynamics of selgantolimod, an oral Toll-like receptor 8 agonist: a Phase Ia study in healthy subjects.

BACKGROUND: Selgantolimod is a novel oral, selective Toll-like receptor 8 (TLR8) agonist in development for the treatment of chronic hepatitis B (CHB). TLR8 is an endosomal innate immune receptor and a target for treatment of viral infections. This first-in-human study investigated the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of selgantolimod in healthy volunteers. METHODS: Of 71 subjects enrolled, 59 received a single dose of selgantolimod (0.5, 1.5, 3 or 5 mg) or placebo, and 12 were evaluated for food effect. Safety, PK and PD activity by induction of cytokines, chemokines and acute phase proteins were assessed. PK/PD analyses were conducted. RESULTS: Single doses of 0.5-5 mg were generally safe. No serious adverse events (AEs) or AEs leading to discontinuation were reported, and most were Grade 1 in severity. Selgantolimod displayed rapid absorption and dose-proportional PK and PD activity. Food had minimal effect on PK but resulted in diminished PD activity. In PK/PD analyses, near-saturation of induction for most evaluated biomarkers occurred at the 5-mg dose. CONCLUSIONS: Single doses of up to 5 mg selgantolimod were safe and induced dose-dependent PD responses. These data support evaluation of selgantolimod in combination with other agents in future clinical studies of CHB. Australian New Zealand Clinical Trials Registration: ACTRN12616001646437.

Is Merkel Cell Carcinoma of Lymph Node Actually Metastatic Cutaneous Merkel Cell Carcinoma?

OBJECTIVES: The possibility of a so-called primary lymph node neuroendocrine carcinoma has been described in the literature. Here we evaluate cases fitting such a diagnosis and find that the cases demonstrate a convincing and pervasive pattern consistent with metastatic Merkel cell carcinoma. METHODS: Six cases of primary lymph node Merkel cell carcinoma and one case of metastatic neuroendocrine carcinoma at a bony site, all with unknown primary, were sequenced using a combination of whole-exome and targeted panel methods. Sequencing results were analyzed for the presence of an ultraviolet (UV) mutational signature or off-target detection of Merkel cell polyomavirus (MCPyV). RESULTS: Four of six primary lymph node cases were positive for a UV mutational signature, with the remaining two cases positive for off-target alignment of MCPyV. One case of neuroendocrine carcinoma occurring at a bony site was also positive for a UV mutational signature. CONCLUSIONS: We find no evidence to corroborate the existence of so-called primary Merkel cell carcinoma of lymph node.

HBV variants are common in the 'immune-tolerant' phase of chronic hepatitis B.

Nucleos(t)ide analogues (NUC) treatment prevents progression of liver fibrosis in subjects with chronic hepatitis B (CHB). However, risk of hepatocellular carcinoma (HCC) persists despite viral suppression. Specific HBV variants have been associated with adverse outcomes, including HCC; however, the frequency of these variants during the seemingly benign immunotolerant (IT) phase is unknown. Next-generation sequencing and detailed virological characterization on a cohort of treatment-naïve IT subjects were performed to determine the frequency of clinically relevant viral variants. Samples from 97 subjects (genotype B/C 55%/45%, median HBV-DNA 8.5 log10 IU/mL, median HBsAg 4.8 log10  IU/mL, median HBeAg 3.6 log10  PEIU/mL) were analysed. Despite subjects being in the IT phase, clinically relevant HBV variants were common at baseline, particularly in the basal core promoter (BCP, overlaps the hepatitis B X (HBx) gene), precore and PreS regions. BCP/HBx variants were independently associated with lower baseline HBeAg, HBsAg and HBV-DNA titres. Precore variants were independently associated with higher baseline ALT. Increased viral diversity was associated with increased age and lower HBV-DNA, HBsAg and HBeAg levels. Low-level (<5%) drug resistance-associated amino acid substitutions in the HBV reverse transcriptase were detected in 9 (9%) subjects at pre-treatment but were not associated with reduced antiviral activity. Future studies should evaluate whether the detection of HBV variant during IT CHB is predictive of progression to immune clearance and poor prognosis, and whether early initiation of antiviral therapy during IT CHB to prevent the selection of HBV variants is clinically beneficial.

Compassionate Use of Remdesivir for Patients with Severe Covid-19.

BACKGROUND: Remdesivir, a nucleotide analogue prodrug that inhibits viral RNA polymerases, has shown in vitro activity against SARS-CoV-2. METHODS: We provided remdesivir on a compassionate-use basis to patients hospitalized with Covid-19, the illness caused by infection with SARS-CoV-2. Patients were those with confirmed SARS-CoV-2 infection who had an oxygen saturation of 94% or less while they were breathing ambient air or who were receiving oxygen support. Patients received a 10-day course of remdesivir, consisting of 200 mg administered intravenously on day 1, followed by 100 mg daily for the remaining 9 days of treatment. This report is based on data from patients who received remdesivir during the period from January 25, 2020, through March 7, 2020, and have clinical data for at least 1 subsequent day. RESULTS: Of the 61 patients who received at least one dose of remdesivir, data from 8 could not be analyzed (including 7 patients with no post-treatment data and 1 with a dosing error). Of the 53 patients whose data were analyzed, 22 were in the United States, 22 in Europe or Canada, and 9 in Japan. At baseline, 30 patients (57%) were receiving mechanical ventilation and 4 (8%) were receiving extracorporeal membrane oxygenation. During a median follow-up of 18 days, 36 patients (68%) had an improvement in oxygen-support class, including 17 of 30 patients (57%) receiving mechanical ventilation who were extubated. A total of 25 patients (47%) were discharged, and 7 patients (13%) died; mortality was 18% (6 of 34) among patients receiving invasive ventilation and 5% (1 of 19) among those not receiving invasive ventilation. CONCLUSIONS: In this cohort of patients hospitalized for severe Covid-19 who were treated with compassionate-use remdesivir, clinical improvement was observed in 36 of 53 patients (68%). Measurement of efficacy will require ongoing randomized, placebo-controlled trials of remdesivir therapy. (Funded by Gilead Sciences.).

Switching from tenofovir disoproxil fumarate to tenofovir alafenamide in virologically suppressed patients with chronic hepatitis B: a randomised, double-blind, phase 3, multicentre non-inferiority study.

BACKGROUND: Treatment with tenofovir disoproxil fumarate has been associated with renal toxicity or reductions in bone mineral density, or both, in some patients with chronic hepatitis B virus (HBV) infection. Tenofovir alafenamide is a tenofovir prodrug with high intrahepatic concentrations of active drug and reduced systemic tenofovir exposures compared with tenofovir disoproxil fumarate. In patients with chronic HBV, tenofovir alafenamide has shown efficacy non-inferior to that of tenofovir disoproxil fumarate with improved renal and bone safety. With this non-inferiority study, we aimed to evaluate the efficacy and safety of tenofovir alafenamide in patients with HBV infection switching from tenofovir disoproxil fumarate who are virally suppressed. METHODS: Patients with chronic HBV infection who had been receiving tenofovir disoproxil fumarate for 48 weeks or more and who had HBV DNA less than the lower limit of quantification (LLOQ) for at least 12 weeks were recruited to this randomised, multicentre, double-blind, phase 3 non-inferiority study. Patients were randomly assigned in a 1:1 ratio to receive tenofovir alafenamide 25 mg once a day or to continue tenofovir disoproxil fumarate 300 mg once a day. The primary efficacy endpoint was loss of virological control, defined as the proportion of patients who received at least one dose of study drug who had HBV DNA of at least 20 IU/mL at week 48 by the modified US Food and Drug Administration (FDA) snapshot algorithm. Key safety endpoints were changes in hip and spine bone mineral density, estimated creatinine clearance by Cockcroft-Gault, and markers of bone turnover and renal tubular function. The study was powered for non-inferiority in efficacy of tenofovir alafenamide versus tenofovir disoproxil fumarate with a 4% margin. Investigators and patients were unaware of treatment allocation and on-treatment results. This trial is ongoing and is registered with ClinicalTrials.gov, number NCT02979613. FINDINGS: Participants in this study were enrolled between Dec 29, 2016, and Oct 20, 2017. 541 patients were screened and 490 patients were randomly assigned to switch to tenofovir alafenamide or to stay on tenofovir disoproxil fumarate. Two patients assigned to receive tenofovir alafenamide did not receive treatment; thus the full analysis set for efficacy and safety analyses consisted of 243 patients in the tenofovir alafenamide group and 245 in the tenofovir disoproxil fumarate group. At week 48, one patient from each treatment group (both <1%) had HBV DNA of at least 20 IU/mL (difference in proportion 0·0%, 95% CI -1·9 to 2·0), thereby showing non-inferior efficacy of tenofovir alafenamide to tenofovir disoproxil fumarate. Patients who received tenofovir alafenamide had significantly increased bone mineral density at hip (mean change 0·66% [SD 2·08] vs -0·51% [SD 1·91]; difference in least square means 1·17% [95% CI 0·80 to 1·54; p<0·0001]) and at spine (mean change 1·74% [3·46] vs -0·11% [3·13]; difference in least square means 1·85% [1·24 to 2·46; p<0·0001]), creatinine clearance by Cockcroft-Gault relative to tenofovir disoproxil fumarate (median change 0·94 mL/min [IQR -4·47 to 6·24] vs -2·74 mL/min [-7·89 to 1·88]; p <0·0001), and improved markers of bone turnover and tubular function at week 48. The most common treatment-emergent adverse events were upper respiratory tract infection (18 [7%] of 243 patients in the tenofovir alafenamide group and 16 [7%] of 245 patients in the tenofovir disoproxil fumarate group) and nasopharyngitis (13 [5%] of 243 patients in the tenofovir alafenamide group and 12 [5%] of 245 patients in the tenofovir disoproxil fumarate group). The incidence of grade 3 and above adverse events and serious adverse events was low and similar between groups. No viral resistance was observed in patients who qualified for viral sequencing. INTERPRETATION: These findings suggest that tenofovir alafenamide can be substituted for tenofovir disoproxil fumarate in patients with HBV infection for improved safety without a loss of efficacy. FUNDING: Gilead Sciences.

Metagenomic Next-Generation Sequencing for Identification and Quantitation of Transplant-Related DNA Viruses.

Infections with DNA viruses are frequent causes of morbidity and mortality in transplant recipients. This study describes the analytical and clinical performance characteristics of the Arc Bio Galileo Pathogen Solution, an all-inclusive metagenomic next-generation sequencing (mNGS) reagent and bioinformatics pipeline that allows the simultaneous quantitation of 10 transplant-related double-stranded DNA (dsDNA) viruses (adenovirus [ADV], BK virus [BKV], cytomegalovirus [CMV], Epstein-Barr virus [EBV], human herpesvirus 6A [HHV-6A], HHV-6B, herpes simplex virus 1 [HSV-1], HSV-2, JC virus [JCV], and varicella-zoster virus [VZV]). The mNGS 95% limit of detection ranged from 14 copies/ml (HHV-6) to 191 copies/ml (BKV), and the lower limit of quantitation ranged from 442 international units (IU)/ml (EBV) to 661 copies/ml (VZV). An evaluation of 50 residual plasma samples with at least one DNA virus detected in prior clinical testing showed a total percent agreement of mNGS and quantitative PCR (qPCR) of 89.2% (306/343), with a κ statistic of 0.725. The positive percent agreement was 84.9% (73/86), and the negative percent agreement was 90.7% (233/257). Furthermore, mNGS detected seven subsequently confirmed coinfections that were not initially requested by qPCR. Passing-Bablok regression revealed a regression line of y = 0.953x + 0.075 (95% confidence interval [CI] of the slope, 0.883 to 1.011; intercept, -0.100 to 0.299), and Bland-Altman analysis (mNGS - qPCR) showed a slight positive bias (0.28 log10 concentration; 95% limits of agreement, -0.62 to 1.18). In conclusion, the mNGS-based Galileo pipeline demonstrates analytical and clinical performance comparable to that of qPCR for transplant-related DNA viruses.

Impact of Pretransplant Donor BK Viruria in Kidney Transplant Recipients.

BACKGROUND: BK virus (BKV) is a significant cause of nephropathy in kidney transplantation. The goal of this study was to characterize the course and source of BKV in kidney transplant recipients. METHODS: We prospectively collected pretransplant plasma and urine samples from living and deceased kidney donors and performed BKV polymerase chain reaction (PCR) and immunoglobulin G (IgG) testing on pretransplant and serially collected posttransplant samples in kidney transplant recipients. RESULTS: Among deceased donors, 8.1% (17/208) had detectable BKV DNA in urine prior to organ procurement. BK viruria was observed in 15.4% (6/39) of living donors and 8.5% (4/47) of deceased donors of recipients at our institution (P = .50). BKV VP1 sequencing revealed identical virus between donor-recipient pairs to suggest donor transmission of virus. Recipients of BK viruric donors were more likely to develop BK viruria (66.6% vs 7.8%; P < .001) and viremia (66.6% vs 8.9%; P < .001) with a shorter time to onset (log-rank test, P < .001). Though donor BKV IgG titers were higher in recipients who developed BK viremia, pretransplant donor, recipient, and combined donor/recipient serology status was not associated with BK viremia (P = .31, P = .75, and P = .51, respectively). CONCLUSIONS: Donor BK viruria is associated with early BK viruria and viremia in kidney transplant recipients. BKV PCR testing of donor urine may be useful in identifying recipients at risk for BKV complications.

Native kidney cytomegalovirus nephritis and cytomegalovirus prostatitis in a kidney transplant recipient.

We present a case of cytomegalovirus (CMV) native kidney nephritis and prostatitis in a CMV D+/R- kidney transplant recipient who had completed six months of CMV prophylaxis four weeks prior to the diagnosis of genitourinary CMV disease. The patient had a history of benign prostatic hypertrophy and urinary retention that required self-catheterization to relieve high post-voiding residual volumes. At 7 months post-transplant, he was found to have a urinary tract infection, moderate hydronephrosis of the transplanted kidney, and severe hydroureteronephrosis of the native left kidney and ureter, and underwent native left nephrectomy and transurethral resection of the prostate. Histopathologic examination of kidney and prostate tissue revealed CMV inclusions consistent with invasive CMV disease. This case highlights that CMV may extend beyond the kidney allograft to involve other parts of the genitourinary tract, including the native kidneys and prostate. Furthermore, we highlight the tissue-specific risk factors that preceded CMV tissue invasion. In addition to concurrent diagnoses, health care providers should have a low threshold for considering late-onset CMV disease in high-risk solid organ transplant recipients presenting with signs and symptoms of genitourinary tract pathology.

Training in transplant infectious diseases: A survey of infectious diseases and transplant infectious diseases fellows in the United States and Canada.

BACKGROUND: Infectious diseases (ID) specialists with experience in managing infections in transplant recipients and other immunocompromised hosts are increasingly needed as these fields expand. METHODS: To evaluate experiences and identify trainee-described needs in transplant infectious diseases (TID) training, the American Society of Transplantation, Infectious Diseases Community of Practice (AST IDCOP) surveyed ID fellows across the United States and TID fellows in the United States and Canada and received responses from 203 ID fellows and 13 TID fellows. RESULTS: Among ID fellows, the amount of TID training during ID fellowship was rated between less than ideal and adequate. Reasons cited included limited frequency of didactic activities and limited exposure to transplant patients during training. In particular, ID fellows at low-volume transplantation centers expressed interest in more TID training time, away training opportunities, and specific TID didactics. Educational resources of high interest among trainees were case-based interactive websites, mobile phone applications with TID guidelines, and a centralized collection of relevant articles. Pediatric ID fellows reported lower satisfaction scores with TID training, while TID fellows were overall satisfied or more than satisfied with their training experience. CONCLUSION: Findings from this survey will inform local and national TID educational initiatives.

Transplant Virus Detection Using Multiplex Targeted Sequencing.

BACKGROUND: Viral infections are a major cause of complications and death in solid organ and hematopoietic cell transplantation. METHODS: We developed a multiplex viral sequencing assay (mVseq) to simultaneously detect 20 transplant-relevant DNA viruses from small clinical samples. The assay uses a single-tube multiplex PCR to amplify highly conserved virus genomic regions without the need for previous virus enrichment or host nucleic acid subtraction. Multiplex sample sequencing was performed using Illumina MiSeq, and reads were aligned to a database of target sequences. Analytical and clinical performance was evaluated using reference viruses spiked into human plasma, as well as patient plasma and nonplasma samples, including bronchoalveolar lavage fluid, cerebrospinal fluid, urine, and tissue from immunocompromised transplant recipients. RESULTS: For the virus spike-in samples, mVseq's analytical sensitivity and dynamic range were similar to quantitative PCR (qPCR). In clinical specimens, mVseq showed substantial agreement with single-target qPCR (92%; k statistic, 0.77; 259 of 282 viral tests); however, clinical sensitivity was reduced (81%), ranging from 62% to 100% for specific viruses. In 12 of the 47 patients tested, mVseq identified previously unknown BK virus, human herpesvirus-7, and Epstein-Barr virus infections that were confirmed by qPCR. CONCLUSIONS: Our results reveal factors that can influence clinical sensitivity, such as high levels of host DNA background and loss of detection in coinfections when 1 virus was at much higher concentration than the others. The mVseq assay is flexible and scalable to incorporate RNA viruses, emerging viruses of interest, and other pathogens important in transplant recipients.

The Human Virome: Implications for Clinical Practice in Transplantation Medicine.

Advances in DNA sequencing technology have provided an unprecedented opportunity to study the human virome. Transplant recipients and other immunocompromised hosts are at particular risk for developing virus-related pathology; thus, the impact of the virome on health and disease may be even more relevant in this population. Here, we discuss technical considerations in studying the human virome, the current literature on the virome in transplant recipients, and near-future applications of sequence-based findings that can further our understanding of viruses in transplantation medicine.