Intradermal delivery of the third dose of the mRNA-1273 SARS-CoV-2 vaccine: safety and immunogenicity of a fractional booster dose

OBJECTIVES

The aim of this study was to assess the safety and immunogenicity of a dose-sparing fractional intradermal (ID) booster strategy with the mRNA-1273 COVID-19 vaccine.

METHODS

COVID-19 naive adults aged 18-30 years were recruited from a previous study on primary vaccination regimens that compared 20 μg ID vaccinations with 100 μg intramuscular (IM) vaccinations with mRNA-1273 as the primary vaccination series. Participants previously immunized with ID regimens were randomly assigned (1:1) to receive a fractional ID booster dose (20 μg) or the standard-of-care intramuscular (IM) booster dose (50 μg) of the mRNA-1273 vaccine, 6 months after completing their primary series (ID-ID and ID-IM group, respectively). Participants that had received a full dose IM regimen as the primary series, received the IM standard-of-care booster dose (IM-IM group). In addition, COVID-19 naive individuals aged 18-40 years who had received an IM mRNA vaccine as the primary series were recruited from the general population to receive a fractional ID booster dose (IM-ID group). Immunogenicity was assessed using IgG anti-spike antibody responses and neutralizing capacity against SARS-CoV-2. Cellular immune responses were measured in a sub-group. Safety and tolerability were monitored.

RESULTS

In January 2022, 129 participants were included in the study. Fractional ID boosting was safe and well tolerated, with fewer systemic adverse events compared with IM boosting. At day 28 post-booster, anti-spike S1 IgG geometric mean concentrations were 9106 (95% CI, 7150-11 597) binding antibody units (BAU)/mL in the IM-IM group and 4357 (3003-6322) BAU/mL; 6629 (4913-8946) BAU/mL; and 5264 (4032-6873) BAU/mL in the ID-IM, ID-ID, and IM-ID groups, respectively.

DISCUSSION

Intradermal boosting provides robust immune responses and is a viable dose-sparing strategy for mRNA COVID-19 vaccines. The favourable side-effect profile supports its potential to reduce vaccine hesitancy. Fractional dosing strategies should be considered early in the clinical development of future mRNA vaccines to enhance vaccine availability and pandemic preparedness.

Immunogenicity and reactogenicity of intradermal mRNA-1273 SARS-CoV-2 vaccination: a non-inferiority, randomized-controlled trial

Fractional dosing can be a cost-effective vaccination strategy to accelerate individual and herd immunity in a pandemic. We assessed the immunogenicity and safety of primary intradermal (ID) vaccination, with a 1/5th dose compared with the standard intramuscular (IM) dose of mRNA-1273 in SARS-CoV-2 naïve persons. We conducted an open-label, non-inferiority, randomized controlled trial in the Netherlands between June and December 2021. One hundred and fifty healthy and SARS-CoV-2 naïve participants, aged 18-30 years, were randomized (1:1:1) to receive either two doses of 20 µg mRNA-1273 ID with a standard needle (SN) or the Bella-mu® needle (BM), or two doses of 100 µg IM, 28 days apart. The primary outcome was non-inferiority in seroconversion rates at day 43 (D43), defined as a neutralizing antibody concentration threshold of 465 IU/mL, the lowest response in the IM group. The non-inferiority margin was set at -15%. Neutralizing antibody concentrations at D43 were 1789 (95% CI: 1488-2150) in the IM and 1263 (951-1676) and 1295 (1020-1645) in the ID-SN and ID-BM groups, respectively. The absolute difference in seroconversion proportion between fractional and standard-dose groups was -13.95% (-24.31 to -3.60) for the ID-SN and -13.04% (-22.78 to -3.31) for the ID-BM group and exceeded the predefined non-inferiority margin. Although ID vaccination with 1/5th dose of mRNA-1273 did not meet the predefined non-inferior criteria, the neutralizing antibody concentrations in these groups are far above the proposed proxy for protection against severe disease (100 IU/mL), justifying this strategy in times of vaccine scarcity to accelerate mass protection against severe disease.

Serology Identifies LIPyV as a Feline Rather than a Human Polyomavirus

The number of identified human polyomaviruses (HPyVs) has increased steadily over the last decade. Some of the novel HPyVs have been shown to cause disease in immunocompromised individuals. The Lyon-IARC polyomavirus (LIPyV) belonging to species Alphapolyomavirus quardecihominis was identified in 2017 in skin and saliva samples from healthy individuals. Since its initial discovery, LIPyV has rarely been detected in human clinical samples but has been detected in faeces from cats with diarrhoea. Serological studies show low LIPyV seroprevalence in human populations. To investigate the possibility that LIPyV is a feline rather than a human polyomavirus, we compared serum IgG responses against the VP1 major capsid protein of LIPyV and 13 other HPyVs among cats (n = 40), dogs (n = 38) and humans (n = 87) using an in-house immunoassay. Seropositivity among cats was very high (92.5%) compared to dogs (31.6%) and humans (2.3%). Furthermore, the median antibody titres against LIPyV were 100-10,000x higher in cats compared to dogs and humans. In conclusion, the high prevalence and intensity of measured seroresponses suggest LIPyV to be a feline rather than a human polyomavirus. Whether LIPyV infection induces diarrhoea or other symptoms in cats remains to be established.

Immune Determinants of Viral Clearance in Hospitalised COVID-19 Patients: Reduced Circulating Naïve CD4+ T Cell Counts Correspond with Delayed Viral Clearance

Virus-specific cellular and humoral responses are major determinants for protection from critical illness after SARS-CoV-2 infection. However, the magnitude of the contribution of each of the components to viral clearance remains unclear. Here, we studied the timing of viral clearance in relation to 122 immune parameters in 102 hospitalised patients with moderate and severe COVID-19 in a longitudinal design. Delayed viral clearance was associated with more severe disease and was associated with higher levels of SARS-CoV-2-specific (neutralising) antibodies over time, increased numbers of neutrophils, monocytes, basophils, and a range of pro-inflammatory cyto-/chemokines illustrating ongoing, partially Th2 dominating, immune activation. In contrast, early viral clearance and less critical illness correlated with the peak of neutralising antibodies, higher levels of CD4 T cells, and in particular naïve CD4+ T cells, suggesting their role in early control of SARS-CoV-2 possibly by proving appropriate B cell help. Higher counts of naïve CD4+ T cells also correlated with lower levels of MIF, IL-9, and TNF-beta, suggesting an indirect role in averting prolonged virus-induced tissue damage. Collectively, our data show that naïve CD4+ T cell play a critical role in rapid viral T cell control, obviating aberrant antibody and cytokine profiles and disease deterioration. These data may help in guiding risk stratification for severe COVID-19.

Humoral response to SARS-CoV-2 infection among liver transplant recipients

OBJECTIVE

Immunosuppressive agents are known to interfere with T and/or B lymphocytes, which are required to mount an adequate serologic response. Therefore, we aim to investigate the antibody response to SARS-CoV-2 in liver transplant (LT) recipients after COVID-19.

DESIGN

Prospective multicentre case-control study, analysing antibodies against the nucleocapsid protein, spike (S) protein of SARS-CoV-2 and their neutralising activity in LT recipients with confirmed SARS-CoV-2 infection (COVID-19-LT) compared with immunocompetent patients (COVID-19-immunocompetent) and LT recipients without COVID-19 symptoms (non-COVID-19-LT).

RESULTS

Overall, 35 LT recipients were included in the COVID-19-LT cohort. 35 and 70 subjects fulfilling the matching criteria were assigned to the COVID-19-immunocompetent and non-COVID-19-LT cohorts, respectively. We showed that LT recipients, despite immunosuppression and less symptoms, mounted a detectable antinucleocapsid antibody titre in 80% of the cases, although significantly lower compared with the COVID-19-immunocompetent cohort (3.73 vs 7.36 index level, p<0.001). When analysing anti-S antibody response, no difference in positivity rate was found between the COVID-19-LT and COVID-19-immunocompetent cohorts (97.1% vs 100%, p=0.314). Functional antibody testing showed neutralising activity in 82.9% of LT recipients (vs 100% in COVID-19-immunocompetent cohort, p=0.024).

CONCLUSIONS

Our findings suggest that the humoral response of LT recipients is only slightly lower than expected, compared with COVID-19 immunocompetent controls. Testing for anti-S antibodies alone can lead to an overestimation of the neutralising ability in LT recipients. Altogether, routine antibody testing against separate SARS-CoV-2 antigens and functional testing show that the far majority of LT patients are capable of mounting an adequate antibody response with neutralising ability.

How to prepare stool banks for an appropriate response to the ongoing COVID-19 pandemic: Experiences in the Netherlands and a retrospective comparative cohort study for faecal microbiota transplantation

Background

Faecal microbiota transplantation (FMT) is an efficacious treatment for patients with recurrent Clostridioides difficile infections (rCDI). Stool banks facilitate FMT by providing screened faecal suspensions from highly selected healthy donors. Due to the ongoing coronavirus disease 2019 (COVID-19) pandemic and the potential risk of SARS coronavirus-2 (SARS-CoV-2) transmission via FMT, many stool banks were forced to temporarily halt and adjust donor activities.

Goal

The evaluation of a strategy to effectively continue stool banking activities during the ongoing COVID-19 pandemic.

Study

To restart our stool banking activities after an initial halt, we implemented periodic SARS-CoV-2 screening in donor faeces and serum, and frequent donor assessment for COVID-19 related symptoms. FMT donor and recipient data obtained before (2016–2019) and during the COVID-19 pandemic (March 2020-August 2021) were compared to assess stool banking efficacy.

Results

Two out of ten donors developed COVID-19. No differences during versus before the COVID-19 pandemic were observed in the number of approved faeces donations (14 vs 22/month, p = 0.06), FMT requests for rCDI (3.9 vs 4.3/month, p = 0.6); rCDI patients eligible for FMT (80.6% vs 73.3%, p = 0.2); rCDI cure rate (90.3% vs 89.2%, p = 0.9); CDI-free survival (p = 0.7); the number of non-rCDI patients treated with FMT (0.5/month vs 0.4/month), and the number of possibly FMT related adverse events (9.5% vs 7.8%, p = 0.7). Two FMTs for rCDI were delayed due to COVID-19.

Conclusions

There is a continued need for FMT treatment of rCDI during the COVID-19 pandemic. Appropriate donor screening and SARS-CoV-2 infection prevention measures can be implemented in existing protocols without increasing the burden for donors, and allow safe, effective and efficient FMT during the ongoing COVID-19 pandemic. Stool banks should evaluate their SARS-CoV-2 donor screening protocols for long-term sustainability and efficacy, and share their experiences to help the utilisation, standardisation and improvement of stool banks worldwide.

Longitudinal Monitoring of DNA Viral Loads in Transplant Patients Using Quantitative Metagenomic Next-Generation Sequencing

Introduction: Immunocompromised patients are prone to reactivations and (re-)infections of multiple DNA viruses. Viral load monitoring by single-target quantitative PCRs (qPCR) is the current cornerstone for virus quantification. In this study, a metagenomic next-generation sequencing (mNGS) approach was used for the identification and load monitoring of transplantation-related DNA viruses. Methods: Longitudinal plasma samples from six patients that were qPCR-positive for cytomegalovirus (CMV), Epstein-Barr virus (EBV), BK polyomavirus (BKV), adenovirus (ADV), parvovirus B19 (B19V), and torque teno-virus (TTV) were sequenced using the quantitative metagenomic Galileo Viral Panel Solution (Arc Bio, LLC, Cambridge, MA, USA) reagents and bioinformatics pipeline combination. Qualitative and quantitative performance was analysed with a focus on viral load ranges relevant for clinical decision making. Results: All pathogens identified by qPCR were also identified by mNGS. BKV, CMV, and HHV6B were additionally detected by mNGS, and could be confirmed by qPCR or auxiliary bioinformatic analysis. Viral loads determined by mNGS correlated with the qPCR results, with inter-method differences in viral load per virus ranging from 0.19 log₁₀ IU/mL for EBV to 0.90 log₁₀ copies/mL for ADV. TTV, analysed by mNGS in a semi-quantitative way, demonstrated a mean difference of 3.0 log₁₀ copies/mL. Trends over time in viral load determined by mNGS and qPCR were comparable, and clinical thresholds for initiation of treatment were equally identified by mNGS. Conclusions: The Galileo Viral Panel for quantitative mNGS performed comparably to qPCR concerning detection and viral load determination, within clinically relevant ranges of patient management algorithms.

Sustained Trichodysplasia Spinulosa Polyomavirus Viremia Illustrating a Primary Disseminated Infection in a Kidney Transplant Recipient

Novel human polyomaviruses (HPyV) have been recently identified in solid organ transplant recipients. Trichodysplasia spinulosa (TS) is a rare disease associated with immunosuppression and induced by a polyomavirus (TSPyV). We report here a case of primary and disseminated TSPyV infection after kidney transplantation with extensive skin lesions, sustained viremia, and high viral loads in urine specimens, anal, nasal and throat swabs, assessed via specific real-time PCR for TSPyV during a follow-up period of 32 months after transplantation. The detection of TSPyV with a high viral load in respiratory and anal swab samples is compatible with viral replication and thus may suggest potential respiratory and oro-fecal routes of transmission.

Convalescent Plasma in a Patient with Protracted COVID-19 and Secondary Hypogammaglobulinemia Due to Chronic Lymphocytic Leukemia: Buying Time to Develop Immunity?

It is not exactly clear yet which type of immune response prevails to accomplish viral clearance in coronavirus disease 2019 (COVID-19). Studying a patient with chronic lymphocytic leukemia and hypogammaglobulinemia who suffered from COVID-19 provided insight in the immunological responses after treatment with COVID-19 convalescent plasma (CCP). Treatment consisted of oxygen, repeated glucocorticosteroids and multiple dosages of CCP guided by antibody levels. Retrospectively performed humoral and cellular immunity analysis made clear that not every serological test for COVID-19 is appropriate for follow-up of sufficient neutralizing antibodies after CCP. In retrospect, we think that CCP merely bought time for this patient to develop an adequate cellular immune response which led to viral clearance and ultimately clinical recovery.

HPV type-specific distribution among family members and linen in households of cutaneous wart patients

Background

Common and plantar warts are caused by human papillomaviruses (HPV). Mode of transmission of wart HPVs within families is largely unknown.

Objective

To demonstrate similarity of HPV type(s) among wart cases, family members and household linen.

Methods

In a cross‐sectional study, swabs taken from 123 warts and foreheads of 62 index patients and 157 family members and from 58 kitchen towels and 59 bathroom mats were tested for DNA of 23 cutaneous wart‐associated HPV types. Generalized estimating equations (GEE) were used to estimate the chance of detecting the same HPV type as was found in the index patients on the family contacts and on the kitchen towels and bathroom mats.

Results

HPV1, HPV2, HPV27 and HPV57 were the most prevalent types in the warts of the index patients. Altogether, 60 (42.3%) of the 142 family members without warts had HPV DNA on their foreheads. When HPV1 and HPV2 were found in the warts, these types were also frequently (>50%) found on the foreheads of index patients and their family members, as well as on the kitchen towels and the bathroom mats. HPV27 and HPV57 were less frequently found (<25%) on foreheads and linen. No associations were found for age, sex and site of HPV DNA presence.

Conclusion

Dissemination of skin wart‐causing HPV types, from wart cases to household contacts and linen, such as kitchen towels and bathroom mats, is more likely for HPV1 and HPV2 than for HPV27 and HPV57. The role of towels and bathroom mats in HPV transmission deserves further investigation.

Linked Commentary A. Kreuter and U. Wieland. J Eur Acad Dermatol Venereol 2022; 36: 11–12. https://doi.org/10.1111/jdv.17820.

Recommendations for the introduction of metagenomic high-throughput sequencing in clinical virology, part I: Wet lab procedure

Metagenomic high-throughput sequencing (mHTS) is a hypothesis-free, universal pathogen detection technique for determination of the DNA/RNA sequences in a variety of sample types and infectious syndromes. mHTS is still in its early stages of translating into clinical application. To support the development, implementation and standardization of mHTS procedures for virus diagnostics, the European Society for Clinical Virology (ESCV) Network on Next-Generation Sequencing (ENNGS) has been established. The aim of ENNGS is to bring together professionals involved in mHTS for viral diagnostics to share methodologies and experiences, and to develop application recommendations. This manuscript aims to provide practical recommendations for the wet lab procedures necessary for implementation of mHTS for virus diagnostics and to give recommendations for development and validation of laboratory methods, including mHTS quality assurance, control and quality assessment protocols.

Rotavirus-Induced Neonatal Epileptic Encephalopathy-A Disease Spectrum Illustrated by Monochorionic Twins

Rotavirus has been associated with neonatal seizures and specific white matter magnetic resonance imaging (MRI) abnormalities. We describe monochorionic twins who not only tested positive for rotavirus with these white matter MRI abnormalities but who also showed an electroencephalogram (EEG) pattern characteristic of early infantile epileptic encephalopathy (EIEE), which has so far solely been described in epileptic encephalopathies with a poor prognosis. This report suggests that rotavirus infection must be added to the list of causes of EIEE EEG, and that the outcome then is likely more favorable. As MRI and EEG signs of rotavirus encephalopathy were present in one twin with only subtle neurologic symptoms, rotavirus may well cause insidious central nervous system complications more often. We suggest considering rotavirus infection in neonates presenting with seizures, and to add rotavirus infection to the differential diagnosis of EIEE.

Primary trichodysplasia spinulosa polyomavirus infection in a kidney transplant child displaying virus-infected decoy cells in the urine

We report a case of primary trichodysplasia spinulosa (TS) infection in a kidney transplant child and describe for the first time the presence of degenerated TS-associated polyomavirus (TSPyV)-infected cells in a TS patient's urine that are morphologically different from BK or JC polyomavirus-infected decoy cells.

Source and Relevance of the BK Polyomavirus Genotype for Infection After Kidney Transplantation

Background

BK polyomavirus (BKPyV)–associated nephropathy (BKPyVAN) is a major threat for kidney transplant recipients (KTRs). The role of specific BKPyV genotypes/serotypes in development of BKPyVAN is poorly understood. Pretransplantation serotyping of kidney donors and recipients and posttransplantation genotyping of viremic recipients, could reveal the clinical relevance of specific BKPyV variants.

Methods

A retrospective cohort of 386 living kidney donor-recipient pairs was serotyped before transplantation against BKPyV genotype I–IV viral capsid protein 1 antigen, using a novel BKPyV serotyping assay. Replicating BKPyV isolates in viremic KTRs after transplantation were genotyped using real-time polymerase chain reaction and confirmed by means of sequencing. BKPyV serotype and genotype data were used to determine the source of infection and analyze the risk of viremia and BKPyVAN.

Results

Donor and recipient BKPyV genotype and serotype distribution was dominated by genotype I (>80%), especially Ib, over II, III and IV. Donor serotype was significantly correlated with the replicating genotype in viremic KTRs (P < .001). Individual donor and recipient serotype, serotype (mis)matching and the recipient replicating BKPyV genotype were not associated with development of viremia or BKPyVAN after transplantation.

Conclusions

BKPyV donor and recipient serotyping and genotyping indicates the donor origin of replicating BKPyV in viremic KTRs but provides no evidence for BKPyV genotype–specific virulence.

Impact of HPyV9 and TSPyV coinfection on the development of BK polyomavirus viremia and associated nephropathy after kidney transplantation

Background

BK polyomavirus (BKPyV) persistently infects the urinary tract and causes viremia and nephropathy in kidney transplantation (KTx), recipients. In a previous study, we observed an increased incidence and load of BKPyV viremia in KTx patients coinfected with human polyomavirus 9 (HPyV9). Here we sought confirmation of this observation and explored whether novel HPyVs that have been detected in urine (HPyV9 and trichodysplasia spinulosa polyomavirus [TSPyV]) potentially aggravate BKPyV infection.

Methods

A well‐characterized cohort of 209 KTx donor‐recipient pairs was serologically and molecularly analyzed for HPyV9 and TSPyV coinfection. These data were correlated with the occurrence of BKPyV viremia and BKPyVAN in the recipients within a year after KTx.

Results

Seropositivity for HPyV9 (19%) and TSPyV (89%) was comparable between donors and recipients and did not correlate with BKPyV viremia and BKPyVAN that developed in 25% and 3% of the recipients, respectively. Two recipients developed TSPyV viremia and none HPyV9 viremia. Modification of the predictive effect of donor BKPyV seroreactivity on recipient BKPyV viremia by HPyV9 and TSPyV was not observed.

Conclusions

Our data provide no evidence for a promoting effect of HPyV9 and TSPyV on BKPyV infection and BKPyVAN in renal allograft patients. Therefore, we do not recommend including HPyV9 and TSPyV screening in KTx patients.

Development and evaluation of a BK polyomavirus serotyping assay using Luminex technology

BACKGROUND

The BK polyomavirus (BKPyV) is subdivided into four genotypes. The consequences of each genotype and of donor-recipient genotype (mis)match for BKPyV-associated nephropathy (BKPyVAN) in kidney transplant recipients (KTRs) are unknown.

OBJECTIVES

To develop and evaluate a genotype-specific IgG antibody-based BKPyV serotyping assay, in order to classify kidney transplant donors and recipients accordingly.

STUDY DESIGN

VP1 antigens of six BKPyV variants (Ib1, Ib2, Ic, II, III and IV) were expressed as recombinant glutathione-s-transferase-fusion proteins and coupled to fluorescent Luminex beads. Sera from 87 healthy blood donors and 39 KTRs were used to analyze seroreactivity and serospecificity against the different BKPyV genotypes. Six sera with marked BKPyV serotype profiles were analyzed further for genotype-specific BKPyV pseudovirus neutralizing capacity.

RESULTS

Seroreactivity was observed against all genotypes, with seropositivity rates above 77% comparable for KTRs and blood donors. Strong cross-reactivity (r > 0.8) was observed among genotype I subtypes, and among genotypes II, III and IV. Seroresponses against genotypes I and IV seemed genuine, while those against II and III could be out(cross)competed. GMT (Luminex) and IC₅₀ (neutralization assay) values showed good agreement in determining the genotype with the strongest seroresponse within an individual.

CONCLUSIONS

Despite some degree of cross-reactivity, this serotyping assay seems a useful tool to identify the main infecting BKPyV genotype within a given individual. This information, which cannot be obtained otherwise from nonviremic/nonviruric individuals, could provide valuable information regarding the prevalent BKPyV genotype in kidney donors and recipients and warrants further study.

Seroprevalence of fourteen human polyomaviruses determined in blood donors

The polyomavirus family currently includes thirteen human polyomavirus (HPyV) species. In immunocompromised and elderly persons HPyVs are known to cause disease, such as progressive multifocal leukoencephalopathy (JCPyV), haemorrhagic cystitis and nephropathy (BKPyV), Merkel cell carcinoma (MCPyV), and trichodysplasia spinulosa (TSPyV). Some recently discovered polyomaviruses are of still unknown prevalence and pathogenic potential. Because HPyVs infections persist and might be transferred by blood components to immunocompromised patients, we studied the seroprevalence of fourteen polyomaviruses in adult Dutch blood donors. For most polyomaviruses the observed seroprevalence was high (60–100%), sometimes slightly increasing or decreasing with age. Seroreactivity increased with age for JCPyV, HPyV6 and HPyV7 and decreased for BKPyV and TSPyV. The most recently identified polyomaviruses HPyV12, NJPyV and LIPyV showed low overall seroprevalence (~5%) and low seroreactivity, questioning their human tropism. Altogether, HPyV infections are common in Dutch blood donors, with an average of nine polyomaviruses per subject.

Human papillomavirus and posttransplantation cutaneous squamous cell carcinoma: A multicenter, prospective cohort study

Organ transplant recipients (OTRs) have a 100-fold increased risk of cutaneous squamous cell carcinoma (cSCC). We prospectively evaluated the association between β genus human papillomaviruses (βPV) and keratinocyte carcinoma in OTRs. Two OTR cohorts without cSCC were assembled: cohort 1 was transplanted in 2003-2006 (n = 274) and cohort 2 was transplanted in 1986-2002 (n = 352). Participants were followed until death or cessation of follow-up in 2016. βPV infection was assessed in eyebrow hair by using polymerase chain reaction-based methods. βPV IgG seroresponses were determined with multiplex serology. A competing risk model with delayed entry was used to estimate cumulative incidence of histologically proven cSCC and the effect of βPV by using a multivariable Cox regression model. Results are reported as adjusted hazard ratios (HRs). OTRs with 5 or more different βPV types in eyebrow hair had 1.7 times the risk of cSCC vs OTRs with 0 to 4 different types (HR 1.7, 95% confidence interval 1.1-2.6). A similar risk was seen with high βPV loads (HR 1.8, 95% confidence interval 1.2-2.8). No significant associations were seen between serum antibodies and cSCC or between βPV and basal cell carcinoma. The diversity and load of βPV types in eyebrow hair are associated with cSCC risk in OTRs, providing evidence that βPV is associated with cSCC carcinogenesis and may present a target for future preventive strategies.

ICTV Virus Taxonomy Profile: Polyomaviridae

The Polyomaviridae is a family of small, non-enveloped viruses with circular dsDNA genomes of approximately 5 kbp. The family includes four genera whose members have restricted host range, infecting mammals and birds. Polyomavirus genomes have also been detected recently in fish. Merkel cell polyomavirus and raccoon polyomavirus are associated with cancer in their host; other members are human and veterinary pathogens. Clinical manifestations are obvious in immunocompromised patients but not in healthy individuals. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the Polyomaviridae, which is available at www.ictv.global/report/polyomaviridae.

Primary Polyomavirus Infection, Not Reactivation, as the Cause of Trichodysplasia Spinulosa in Immunocompromised Patients

Classic human polyomaviruses (JC and BK viruses) become pathogenic when reactivating from latency. For the rare skin disease trichodysplasia spinulosa, we show that manifestations of the causative polyomavirus (TSPyV) occur during primary infection of the immunosuppressed host. High TSPyV loads in blood and cerebrospinal fluid, sometimes coinciding with cerebral lesions and neuroendocrine symptoms, marked the acute phase of trichodysplasia spinulosa, whereas initiation and maturation of TSPyV seroresponses occurred in the convalescent phase. TSPyV genomes lacked the rearrangements typical for reactivating polyomaviruses. These findings demonstrate the clinical importance of primary infection with this rapidly expanding group of human viruses and explain the rarity of some novel polyomavirus-associated diseases.

Stability of BK polyomavirus IgG seroreactivity and its correlation with preceding viremia

BACKGROUND

Recently we showed that the level of BK polyomavirus (BKPyV) IgG seroreactivity in kidney donors predicted viremia and BKPyV-associated nephropathy in kidney transplant recipients (KTRs). This observation could be explained by assuming a direct association between BKPyV seroreactivity and the amount of persistent infectious virus in the renal allograft.

OBJECTIVES

Since the renal BKPyV reservoir is probably sowed by viremia during primary BKPyV infection, we systematically analysed the dynamics of BKPyV IgG seroreactivity in relation to preceding BKPyV viremia in KTRs and healthy individuals.

STUDY DESIGN

A cohort of 85 KTRs consisting of BKPyV viremic and nonviremic subjects was analysed for BKPyV IgG seroreactivity at five fixed time points until one year after transplantation. A cohort of 87 healthy blood donors (HBDs) was used as controls.

RESULTS

Baseline BKPyV seropositivity was high in both KTRs and HBDs, and the baseline mean BKPyV IgG level comparable. BKPyV IgG levels in nonviremic KTRs and HBDs remained stable during follow-up, while a considerable increase was observed in viremic KTRs (p=0.015). The increase of BKPyV seroreactivity in viremic KTRs was associated with the duration and peak level of BKPyV viremia.

CONCLUSIONS

BKPyV IgG seroreactivity was stable over time in immunocompetent subjects, which enables the use of this potential pretransplantation biomarker in kidney donors. The observed dose-dependent relationship of BKPyV IgG seroreactivity with preceding BKPyV replication is in agreement with the assumption that BKPyV seroreactivity reflects past BKPyV activity and correlates with the amount of latent BKPyV residing within a kidney allograft.

Pretransplantation Donor-Recipient Pair Seroreactivity Against BK Polyomavirus Predicts Viremia and Nephropathy After Kidney Transplantation

Kidney transplant donors are not currently implicated in predicting BK polyomavirus (BKPyV) infection in kidney transplant recipients. It has been postulated, however, that BKPyV infection originates from the kidney allograft. Because BKPyV seroreactivity correlates with BKPyV replication and thus might mirror the infectious load, we investigated whether BKPyV seroreactivity of the donor predicts viremia and BKPyV-associated nephropathy (BKPyVAN) in the recipient. In a retrospective cohort of 407 living kidney donor-recipient pairs, pretransplantation donor and recipient sera were tested for BKPyV IgG levels and correlated with the occurrence of recipient BKPyV viremia and BKPyVAN within 1 year after transplantation. Donor BKPyV IgG level was strongly associated with BKPyV viremia and BKPyVAN (p < 0.001), whereas recipient BKPyV seroreactivity showed a nonsignificant inverse trend. Pairing of high-BKPyV-seroreactive donors with low-seroreactive recipients resulted in a 10-fold increased risk of BKPyV viremia (hazard ratio 10.1, 95% CI 3.5-29.0, p < 0.001). In multivariate analysis, donor BKPyV seroreactivity was the strongest pretransplantation factor associated with viremia (p < 0.001) and BKPyVAN (p = 0.007). The proportional relationship between donor BKPyV seroreactivity and recipient infection suggests that donor BKPyV seroreactivity reflects the infectious load of the kidney allograft and calls for the use of pretransplantation BKPyV serological testing of (potential) donors and recipients.

Clinically Relevant Reactivation of Polyomavirus BK (BKPyV) in HLA-A02-Positive Renal Transplant Recipients Is Associated with Impaired Effector-Memory Differentiation of BKPyV-Specific CD8+ T Cells

Polyomavirus BK (BKPyV) frequently reactivates in immunosuppressed renal transplant recipients (RTRs) and may lead to graft loss due to BKPyV-induced interstitial nephritis (BKVN). Little is known on the differentiation of CD8⁺ T cells targeting BKPyV in RTRs. Here we investigated whether BKPyV-specific CD8⁺ T cell differentiation differs in RTRs with varying degrees of BKPyV reactivation and/or BKVN.

Using combinatorial encoding with tetramers carrying BKPyV major capsid protein (VP1) and large T antigen protein (LTAG) epitopes, we investigated CD8⁺ T cell responses to BKPyV in longitudinally obtained PBMC samples from 46 HLA-A02-positive RTRs and 20 healthy adults. We were also able to isolate BKPyV-specific CD8⁺ T cells from five renal allografts, two of which were affected by BKVN.

Before transplantation, BKPyV-specific CD8⁺ T cells targeting VP1 and LTAG epitopes appeared predominantly as central-memory and CD27⁺/CD28⁺ effector-memory (T_EM), and naïve-like PD-1-expressing cells, respectively. After viral reactivation, BKPyV-specific CD8⁺ T cells assumed CD28⁻ T_EM and T_EMRA states in patients who were able to control BKPyV, whereas differentiation lagged behind in patients with severe viral reactivation or BKVN. Furthermore, VP1-specific CD69⁺/CD103⁺ tissue-resident memory (T_RM) cells accumulated in BKVN-affected allografts but lacked signs of effector differentiation. In contrast, granzyme B-expressing effector cells were detected in allografts not affected by BKVN.

In conclusion, effector-memory differentiation of BKPyV-specific CD8⁺ T cells in patients with high viral load or BKVN is impaired. Further characterization of the specific mechanisms behind this altered cellular differentiation is necessary to develop therapies that can prevent the emergence of BKVN.

In immunosuppressed renal transplant recipients (RTRs), BKPyV frequently reactivates from latency and may cause severe interstitial nephritis in the allograft (BKVN). Not only is there no effective treatment, it also not understood why BKVN arises in some RTRs but not in all. In the current study we investigated populations of CD8⁺ T cells targeting epitopes from structural and non-structural BKPyV proteins in RTRs over the course of transplantation. In contrast to RTRs who suffered from self-limiting reactivation of BKPyV, patients who developed severe viral reactivation and BKVN were found to have BKPyV-specific CD8⁺ T cells which did not, or less often differentiate into CD28⁻ effector-memory cells during viral reactivation. Moreover, virus-specific CD8⁺ T cell activation and differentiation was not only impaired in the circulation, but possibly also in BKVN-affected renal allografts. In contrast to the CD8⁺ T cells in kidneys from three patients who did not develop BKVN, T cells in two BKVN-affected kidneys did not display typical cytotoxic effector traits. These findings suggest that impaired BKPyV-specific CD8⁺ T cell maturation in response to viral reactivation, possibly owing to inter-individual differences in sensitivity to immunosuppressive medication or to certain viral quasispecies, underlies the emergence of severe viral reactivation and BKVN.

Trichodysplasia spinulosa-Associated Polyomavirus Uses a Displaced Binding Site on VP1 to Engage Sialylated Glycolipids

Trichodysplasia spinulosa-associated Polyomavirus (TSPyV) was isolated from a patient suffering from trichodysplasia spinulosa, a skin disease that can appear in severely immunocompromised patients. While TSPyV is one of the five members of the polyomavirus family that are directly linked to a human disease, details about molecular recognition events, the viral entry pathway, and intracellular trafficking events during TSPyV infection remain unknown. Here we have used a structure-function approach to shed light on the first steps of TSPyV infection. We established by cell binding and pseudovirus infection studies that TSPyV interacts with sialic acids during attachment and/or entry. Subsequently, we solved high-resolution X-ray structures of the major capsid protein VP1 of TSPyV in complex with three different glycans, the branched GM1 glycan, and the linear trisaccharides α2,3- and α2,6-sialyllactose. The terminal sialic acid of all three glycans is engaged in a unique binding site on TSPyV VP1, which is positioned about 18 Å from established sialic acid binding sites of other polyomaviruses. Structure-based mutagenesis of sialic acid-binding residues leads to reduction in cell attachment and pseudovirus infection, demonstrating the physiological relevance of the TSPyV VP1-glycan interaction. Furthermore, treatments of cells with inhibitors of N-, O-linked glycosylation, and glycosphingolipid synthesis suggest that glycolipids play an important role during TSPyV infection. Our findings elucidate the first molecular recognition events of cellular infection with TSPyV and demonstrate that receptor recognition by polyomaviruses is highly variable not only in interactions with sialic acid itself, but also in the location of the binding site.

Viruses engage receptors on their host cell to initiate entry and infection. Members within a virus family are known to target different tissues and hosts and exploit different pathogenic mechanisms due to critical changes in receptor specificity. The human Trichodysplasia spinulosa-associated Polyomavirus (TSPyV) is known to cause a rare skin disease in immunocompromised individuals. The pathogenic mechanism includes hyperproliferation of inner root sheath cells, but molecular determinants underlying the infection and the associated disease remain unknown. Here we applied a structural and functional approach to investigate the recognition events during early infection steps of the virus. We found that TSPyV engages sialic acid receptors but employs a novel binding site on the capsid that is shifted in comparison to other structurally characterized polyomaviruses. Cell-based studies demonstrate the relevance of the observed interaction for attachment and infection and suggest that glycolipids, rather than N- and O-linked glycoproteins, are important for infection. Our findings demonstrate exemplarily that receptor recognition by (polyoma-) viruses is highly variable not only in interactions with sialic acids, but also in the location of the binding site on the capsid, providing insights about structural determinants of receptor and host specificity and evolution of these viruses.

Interspecific adaptation by binary choice at de novo polyomavirus T antigen site through accelerated codon-constrained Val-Ala toggling within an intrinsically disordered region

It is common knowledge that conserved residues evolve slowly. We challenge generality of this central tenet of molecular biology by describing the fast evolution of a conserved nucleotide position that is located in the overlap of two open reading frames (ORFs) of polyomaviruses. The de novo ORF is expressed through either the ALTO protein or the Middle T antigen (MT/ALTO), while the ancestral ORF encodes the N-terminal domain of helicase-containing Large T (LT) antigen. In the latter domain the conserved Cys codon of the LXCXE pRB-binding motif constrains codon evolution in the overlapping MT/ALTO ORF to a binary choice between Val and Ala codons, termed here as codon-constrained Val-Ala (COCO-VA) toggling. We found the rate of COCO-VA toggling to approach the speciation rate and to be significantly accelerated compared to the baseline rate of chance substitution in a large monophyletic lineage including all viruses encoding MT/ALTO and three others. Importantly, the COCO-VA site is located in a short linear motif (SLiM) of an intrinsically disordered region, a typical characteristic of adaptive responders. These findings provide evidence that the COCO-VA toggling is under positive selection in many polyomaviruses, implying its critical role in interspecific adaptation, which is unprecedented for conserved residues.

Human polyomavirus 9 infection in kidney transplant patients

This virus is frequently found within the first year after transplantation and in association with BK polyomavirus infection.

Several human polyomaviruses of unknown prevalence and pathogenicity have been identified, including human polyomavirus 9 (HPyV9). To determine rates of HPyV9 infection among immunosuppressed patients, we screened serum samples from 101 kidney transplant patients in the Netherlands for HPyV9 DNA and seroreactivity. A total of 21 patients had positive results for HPyV9 DNA; positivity rates peaked at 3 months after transplantation, but the highest viral loads were measured just after transplantation. During 18 months of follow-up, HPyV9 seroprevalence increased from 33% to 46% among transplant patients; seroprevalence remained stable at ≈30% in a control group of healthy blood donors in whom no HPyV9 DNA was detected. Further analysis revealed an association between detection of HPyV9 and detection of BK polyomavirus but not of cytomegalovirus. Our data indicate that HPyV9 infection is frequent in kidney transplant patients, but the nature of infection—endogenous or donor-derived—and pathogenic potential of this virus remain unknown.

High prevalence of cutaneous warts in elementary school children and the ubiquitous presence of wart-associated human papillomavirus on clinically normal skin

BACKGROUND

One-third of Dutch primary school children have cutaneous warts; each year around 20% of them seek medical treatment. However, little is known about the epidemiology of the types of human papillomavirus (HPV) causing these warts.

OBJECTIVES

To investigate the distribution of cutaneous wart-associated HPV types in three primary school classes by analysing skin swabs taken from warts, and the forehead, hand dorsum and sole of the foot of included children.

METHODS

Using the hyperkeratotic skin lesion polymerase chain reaction/multiplex genotyping assay, each swab sample was used to genotype for 23 cutaneous wart-associated HPV types.

RESULTS

Thirty-one (44%) of the 71 children had a total of 69 warts, with a maximum of six warts per child. In the wart swabs, HPV2, HPV27 and HPV57, members of Alphapapillomavirus species 4, were most frequently detected (27%, 32% and 14%, respectively), whereas HPV1 was only found in two plantar warts. The prevalence of HPV carriage, detected in swabs of clinically normal skin of the forehead, left hand and left sole was 80%, with the most prevalent types being HPV1 (59%), HPV2 (42%), HPV63 (25%) and HPV27 (21%).

CONCLUSIONS

Cutaneous wart-associated HPV types were highly prevalent in primary school children, but did not correlate with the HPV types in warts. In contrast to the existing literature, HPV1 was frequently detected on clinically normal skin but was much less frequent in warts.

From Stockholm to Malawi: recent developments in studying human polyomaviruses

Until a few years ago the polyomavirus family (Polyomaviridae) included a dozen viruses identified in avian and mammalian hosts. Two of these, the JC and BK-polyomaviruses isolated a long time ago, are known to infect humans and cause severe illness in immunocompromised hosts. Since 2007 an unprecedented number of eight novel polyomaviruses were discovered in humans. Among them are the KI- and WU-polyomaviruses identified in respiratory samples, the Merkel cell polyomavirus found in skin carcinomas and the polyomavirus associated with trichodysplasia spinulosa, a skin disease of transplant patients. Another four novel human polyomaviruses were identified, HPyV6, HPyV7, HPyV9 and the Malawi polyomavirus, so far not associated with any disease. In the same period several novel mammalian polyomaviruses were described. This review summarizes the recent developments in studying the novel human polyomaviruses, and touches upon several aspects of polyomavirus virology, pathogenicity, epidemiology and phylogeny.

Human papillomavirus load in eyebrow hair follicles and risk of cutaneous squamous cell carcinoma

BACKGROUND

Beta-human papillomavirus (betaPV) may play a role in the development of cutaneous squamous cell carcinoma (SCC). However betaPV is highly prevalent, and it may only be people with a higher viral load who have increased risk of SCCs. We therefore examined the association between betaPV load and SCCs.

METHODS

We recruited 448 immunocompetent cases with SCCs and 464 controls from Italy and Australia and 497 immunosuppressed organ transplant recipients (OTR; 179 cases and 318 controls) from Europe. We used reverse hybridization to genotype 25 betaPV types in eyebrow hair follicles and determined the viral load for eight selected types using quantitative PCR. We used logistic regression to assess associations between type-specific and cumulative viral load and SCCs.

RESULTS

Australian and OTR participants in the highest cumulative load tertile were at significantly higher risk of SCCs than those in the lowest tertile. Those with more than four betaPV types in the high load tertile were at approximately three-fold increased risk of SCCs. In Australia, HPV23 and 36 loads were significantly associated with SCCs, with borderline associations for HPV5 and 38. In OTR, HPV8 and 38 loads were significantly associated and HPV20 and 36 were borderline. We found little evidence for an association between load and SCCs in Italy.

CONCLUSIONS

High viral load may be associated with risk of cutaneous SCCs, with total load seemingly more important than the load of any specific type.

IMPACT

Our findings lend weight to the hypothesis that HPV plays a role in skin carcinogenesis.

Longitudinal study of seroprevalence and serostability of 34 human papillomavirus types in European organ transplant recipients

Organ transplant recipients (OTR) are at increased risk of cutaneous squamous cell carcinoma, which may be related to reactivation of human papillomavirus (HPV) infections. Measurement of change in HPV antibodies after transplantation would help to explore this hypothesis. We measured antibodies to 34 HPV types on up to six occasions over 18 months in 441 OTRs from five European countries. At baseline (mean 24 days after transplantation), 80% of all OTRs were seropositive to at least one HPV type. The beta HPV genus had the highest seroprevalence (45%). For most HPV genera baseline seroprevalence peaked between 40 and 59 years old. Most OTRs retained their serostatus over time and antibody levels were stable. Seroprevalence in immunosuppressed OTRs is stable in the 18 months immediately after transplantation. Thus there is no short-term evidence that immunosuppression leads to new or reactivated skin infection with HPV sufficient to induce antibodies.

Cutaneous wart-associated HPV types: prevalence and relation with patient characteristics

BACKGROUND

Epidemiological data on cutaneous wart-associated HPV types are rare.

OBJECTIVES

To examine the prevalence of cutaneous wart-associated HPV types and their relation with patient characteristics.

STUDY DESIGN

Swabs were taken from all 744 warts of 246 consecutive immunocompetent participants and analysed by a broad spectrum HSL-PCR/MPG assay. Patient details including location, duration, and number of warts were recorded.

RESULTS

No HPV DNA was detected in 49 (7%) swabs, a single HPV type in 577 (78%) swabs, and multiple HPV types in 118 (16%) swabs. HPV 2, 27 and 57 (alpha genus), HPV 4 (gamma genus) and HPV 1 (mu genus) were the most frequently detected HPV types, and HPV 63 (mu genus) was only frequently detected together with other HPV types. Less frequently detected HPV types were HPV 3, 7, 10 and 28 (alpha genus), 65, 88 and 95 (gamma genus) and 41 (nu genus). Warts containing HPV 1 showed the most distinct clinical profile, being related to children aged <12 years, plantar location, duration <6 months, and to patients with <4 warts.

CONCLUSIONS

HPV 27, 57, 2 and 1 are the most prevalent HPV types in cutaneous warts in general population. Warts infected with HPV 1 have a distinct clinical profile.

Human papillomavirus 8 E6 disrupts terminal skin differentiation and prevents pro-Caspase-14 cleavage

Expression of the betapapillomavirus (betaPV) E6/E7 genes has been shown to impair both keratinocyte differentiation and apoptosis. Especially late-terminal keratinocyte differentiation shares certain aspects with apoptosis, such as fragmentation of DNA and activation of caspases. Here we investigated the disruption of keratinocyte differentiation in organotypic skin (raft) cultures of primary (PHK) and immortalized (N/TERT) human keratinocytes, in particular by human papillomavirus (HPV)8. Immunohistochemical analysis of HPV5 and HPV8 E6/E7-expressing PHK revealed thickening of the rafts and complete absence of stratum corneum formation, even after 18 days of culture. This phenotype was confirmed in N/TERT raft cultures. When expressed separately, the aberrant morphology was observed only in rafts expressing E6, not E7. Immunofluorescence analysis of HPV8 E6 PHK rafts showed an increase in number and size of Filaggrin- and Caspase-14-positive cells in the granular layer. In raft lysates analyzed by western-blot, the presence of pro-Caspase-14 in the differentiated keratinocytes was confirmed, but in the HPV8 E6 rafts none of the Caspase-14 subunits were detected. In conclusion, in the raft system, HPV8 E6 prevented late-terminal keratinocyte differentiation resulting in an accumulation of Filaggrin and pro-Caspase-14-positive cells in the absence of stratification. This differentiation arrest was accompanied by the failure to express Caspase-14 subunits, suggesting absence of Caspase-14 activation and probable abrogation of Filaggrin maturation in HPV8 E6-expressing keratinocytes.

Trichodysplasia spinulosa is characterized by active polyomavirus infection

BACKGROUND

Recently a new polyomavirus was identified in a patient with trichodysplasia spinulosa (TS), a rare follicular skin disease of immunocompromised patients characterized by facial spines and overgrowth of inner root sheath cells. Seroepidemiological studies indicate that TSPyV is ubiquitous and latently infects 70% of the healthy individuals.

OBJECTIVE

To corroborate the relationship between active TSPyV infection and TS disease by analyzing the presence, load, and precise localization of TSPyV infection in TS patients and in controls.

STUDY DESIGN

TS lesional and non-lesional skin samples were retrieved from TS patients through a PubMed search. Samples were analyzed for the presence and load of TSPyV DNA with quantitative PCR, and for expression and localization of viral protein with immunofluorescence. Findings obtained in TS patients (n=11) were compared to those obtained in healthy controls (n=249).

RESULTS

TSPyV DNA detection was significantly associated with disease (P<0.001), with 100% positivity of the lesional and 2% of the control samples. Quantification revealed high TSPyV DNA loads in the lesional samples (∼10(6)copies/cell), and low viral loads in the occasionally TSPyV-positive non-lesional and control samples (<10(2)copies/cell). TSPyV VP1 protein expression was detected only in lesional TS samples, restricted to the nuclei of inner root sheath cells over-expressing trichohyalin.

CONCLUSIONS

The high prevalence and load of TSPyV DNA only in TS lesions, and the abundant expression of TSPyV protein in the affected hair follicle cells demonstrate a tight relation between TSPyV infection and TS disease, and indicate involvement of active TSPyV infection in TS pathogenesis.

Seroprevalence of trichodysplasia spinulosa-associated polyomavirus

We identified a new polyomavirus in skin lesions from a patient with trichodysplasia spinulosa (TS). Apart from TS being an extremely rare disease, little is known of its epidemiology. On the basis of knowledge regarding other polyomaviruses, we anticipated that infections with trichodysplasia spinulosa-associated polyomavirus (TSV) occur frequently and become symptomatic only in immunocompromised patients. To investigate this hypothesis, we developed and used a Luminex-based TSV viral protein 1 immunoassay, excluded cross-reactivity with phylogenetically related Merkel cell polyomavirus, and measured TSV seroreactivity. Highest reactivity was found in a TS patient. In 528 healthy persons in the Netherlands, a wide range of seroreactivities was measured and resulted in an overall TSV seroprevalence of 70% (range 10% in small children to 80% in adults). In 80 renal transplant patients, seroprevalence was 89%. Infection with the new TSV polyomavirus is common and occurs primarily at a young age.

Factors associated with the seroprevalence of 26 cutaneous and two genital human papillomavirus types in organ transplant patients

Viral skin infections are commonly present in organ transplant recipients (OTR). In this study, we aimed to identify factors associated with human papillomavirus (HPV) infections in OTR. Patients with solid-organ transplants were recruited from the outpatient nephrology and dermatology clinics in five European countries. Only patients with no current or past skin cancer were included in this analysis. Serum samples were analysed for antibodies to the L1 proteins of 26 cutaneous and two genital HPV types from five phylogenetic genera (α, β, γ, μ and ν). The most consistent association was found between recreational sun exposure and the seroprevalence of all tested genera, except α. The antibody presence of any β type was higher among people who had been transplanted at least 23 years prior to participation than in those who had been transplanted for less than 7 years. The prevalence of two γ-HPV types (60 and 65) and three β-HPV types (15, 38 and 49) was associated with time since transplantation. The presence of a high number of warts was associated with the presence of any μ-PV or ν-PV types, and having greater than 50 keratotic skin lesions was almost significantly associated with the presence of antibodies to two or more γ-PV. Discrepancies in the results of the present study, as well as in previous reports, may depend on different methodologies and on geographical variations. Our results also indicate that further research with more standardized methods is needed to clarify the role of cutaneous HPV in OTR.

A case-control study of betapapillomavirus infection and cutaneous squamous cell carcinoma in organ transplant recipients

We examined the association between betapapillomavirus (betaPV) infection and cutaneous squamous cell carcinoma (SCC) in organ transplant recipients. A total of 210 organ transplant recipients with previous SCC and 394 controls without skin cancer were included. The presence of 25 betaPV types in plucked eyebrow hairs was determined using a human papillomavirus (HPV) DNA genotyping assay, and antibodies for the 15 most prevalent betaPV types were detected using multiplex serology. We used multivariate logistic regression models to estimate associations between various measures of betaPV infection and SCC. BetaPV DNA was highly prevalent (>94%) with multiple types frequently detected in both groups. We found a significant association between SCC and the concordant detection of both antibodies and DNA for at least one betaPV type (adjusted OR 1.6; 95% CI 1.1;2.5). A borderline-significant association with SCC was found for HPV36 (adjusted OR 2.4; CI 1.0;5.4), with similar associations for HPV5, HPV9 and HPV24. These data provide further evidence of an association between betaPV infection and SCC in organ transplant recipients. Confirmation of a betaPV profile predictive of risk for SCC may pave the way for clinically relevant pretransplant HPV screening and the development of preventive and therapeutic HPV vaccination.

Marked differences in Betapapillomavirus DNA and antibody prevalence between patients with psoriasis and those with atopic dermatitis

BACKGROUND

Recent studies revealed that Betapapillomavirus (betaPV) infections are highly prevalent. Skin diseases such as psoriasis, characterized by keratinocyte hyperproliferation, and atopic dermatitis (AD), dominated by cutaneous inflammation, might have an impact on viral life cycle and immune response induction.

OBJECTIVES

To investigate whether betaPV infection is different in psoriasis and AD.

METHODS

Twenty-seven patients with psoriasis and 17 with AD were included for betaPV genotyping using eyebrow hairs, and for seroresponse determination.

RESULTS

BetaPV DNA was found significantly more often in patients with psoriasis than in those with AD (100% vs. 81%, P=0·022) and the mean number of betaPV types was higher (4·8 vs. 2·1 types, P=0·002). In contrast, the seroprevalence in patients with AD was significantly higher compared with that in patients with psoriasis (88% vs. 56%, P=0·023). Type-specific concordance of serological response to the betaPV type detected in eyebrow hairs was 27% in patients with psoriasis and 47% in those with AD (P=0·019).

CONCLUSIONS

We speculate that the condition of the skin and the immunological state of the patients have an important impact on the life cycle of betaPV.

The Association between cutaneous squamous cell carcinoma and betapapillomavirus seropositivity: a cohort study

BACKGROUND

It is currently unclear whether betapapillomaviruses (betaPV) play a role in the etiology of cutaneous squamous cell carcinoma (SCC). We investigated the association between betaPV antibodies and subsequent SCC in a population-based cohort study.

METHODS

Serum samples were collected in 1992 and/or 1996 from 1,311 participants of the community-based Nambour Skin Cancer Study. These were tested for the presence of L1 antibodies against 21 different betaPV types. Histologically diagnosed SCCs were ascertained through three full-body skin examinations and linkage with the local pathology laboratories. We used age- and sex-adjusted Cox proportional hazards models to analyze the relationship between betaPV antibodies and SCC occurrence from 1992 until 2007.

RESULTS

SCC was newly diagnosed in 150 people. No associations were found between the presence of any betaPV L1 antibodies and the occurrence of SCC (HR = 1.0), and stratification by sex, skin color, and sunburn propensity did not affect these results. However, among people who were less than 50 years old in 1992, the presence of betaPV antibodies was associated with a two-fold increased risk of SCC. There was no significant association between antibodies to any individual betaPV type examined and the later development of SCC.

CONCLUSIONS

Whether betaPV infection of the skin, and indirectly betaPV antibodies, are involved in the oncogenic process in the general population remains unclear, and this longitudinal study provides only limited support.

IMPACT

This study emphasizes the need for additional longitudinal studies of HPV (human papilloma virus) and SCC, to avoid the possibility of reverse causality in case--control studies.

Discovery of a new human polyomavirus associated with trichodysplasia spinulosa in an immunocompromized patient

The Polyomaviridae constitute a family of small DNA viruses infecting a variety of hosts. In humans, polyomaviruses can cause infections of the central nervous system, urinary tract, skin, and possibly the respiratory tract. Here we report the identification of a new human polyomavirus in plucked facial spines of a heart transplant patient with trichodysplasia spinulosa, a rare skin disease exclusively seen in immunocompromized patients. The trichodysplasia spinulosa-associated polyomavirus (TSV) genome was amplified through rolling-circle amplification and consists of a 5232-nucleotide circular DNA organized similarly to known polyomaviruses. Two putative “early” (small and large T antigen) and three putative “late” (VP1, VP2, VP3) genes were identified. The TSV large T antigen contains several domains (e.g. J-domain) and motifs (e.g. HPDKGG, pRb family-binding, zinc finger) described for other polyomaviruses and potentially involved in cellular transformation. Phylogenetic analysis revealed a close relationship of TSV with the Bornean orangutan polyomavirus and, more distantly, the Merkel cell polyomavirus that is found integrated in Merkel cell carcinomas of the skin. The presence of TSV in the affected patient's skin was confirmed by newly designed quantitative TSV-specific PCR, indicative of a viral load of 10⁵ copies per cell. After topical cidofovir treatment, the lesions largely resolved coinciding with a reduction in TSV load. PCR screening demonstrated a 4% prevalence of TSV in an unrelated group of immunosuppressed transplant recipients without apparent disease. In conclusion, a new human polyomavirus was discovered and identified as the possible cause of trichodysplasia spinulosa in immunocompromized patients. The presence of TSV also in clinically unaffected individuals suggests frequent virus transmission causing subclinical, probably latent infections. Further studies have to reveal the impact of TSV infection in relation to other populations and diseases.

Diseases that occur exclusively in immunocompromized patients are often of an infectious nature. Trichodysplasia spinulosa (TS) is such a disease characterized by development of papules, spines and alopecia in the face. Fortunately this disease is rare, because facial features can change dramatically, as in the case of an adolescent TS patient who was on immunosuppressive drugs because of heart-transplantation. A viral cause of TS was suspected already for some time because virus particles had been seen in TS lesions. In pursuit of this unknown virus, we isolated DNA from collected TS spines and could detect a unique small circular DNA suggestive of a polyomavirus genome. Additional experiments confirmed the presence in these samples of a new polyomavirus that we tentatively called TS-associated polyomavirus (TSPyV or TSV). TSV shares several properties with other polyomaviruses, such as genome organization and proteome composition, association with disease in immunosuppressed patients and occurence in individuals without overt disease. The latter indicates that TSV circulates in the human population. Future studies have to show how this newly identified polyomavirus spreads, how it causes disease and if it is related to other (skin) conditions as well.

Lack of association between the presence and persistence of betapapillomavirus DNA in eyebrow hairs and betapapillomavirus L1 antibodies in serum

Betapapillomavirus (betaPV) DNA and seroresponses are highly prevalent in the general population and both are frequently used as infection markers in epidemiological studies to elucidate an association with cutaneous squamous cell carcinoma (SCC). Little is known about the natural history of betaPV infection and the aspects of infection that drive antibody responses. To investigate the relationship between these markers, this study assessed whether the presence or persistence of betaPV DNA in eyebrow hairs and L1 antibodies of the same betaPV type co-occurred more frequently than would be expected by chance in both a cross-sectional assessment and a longitudinal study. betaPV DNA in plucked eyebrow hairs and L1 antibodies in serum were measured in 416 participants of the Australian community-based Nambour Skin Cancer Study in 1996. Similar data were available for a subset of 148 participants in 2003. Observed co-occurrence of betaPV DNA and antibodies was compared with expected values based on prevalence. A case-wise concordance index was used to calculate the overall concordance of betaPV DNA and antibodies of the same type. No significant associations were found between the presence or persistence of betaPV DNA and antibody responses. The age and sex of the host did not influence the association, and nor did SCC status or a history of sunburns. It was concluded that betaPV antibody responses in adults are not primarily driven by betaPV infection as measured in eyebrow hairs. Other factors, such as viral load, may play a more pivotal role in the induction of detectable seroresponses.

Betapapillomavirus infection profiles in tissue sets from cutaneous squamous cell-carcinoma patients

Human papillomaviruses from the genus beta (betaPV) are a possible cause of cutaneous squamous cell carcinoma (SCC). We compared the betaPV infections in SCC and in sets of cutaneous tissues collected from a series of individual SCC patients to determine concordance and to assess the adequacy of eyebrow hairs as noninvasive markers of betaPV infection. Biopsies of SCC tumors, perilesional tissue, normal skin from the mirror image of nonfacial SCC and plucked eyebrow hairs were collected from 21 patients with incident SCC living in Queensland, Australia. These were tested for the presence of DNA from 25 different betaPV types. Overall prevalence of betaPV was high in every sample type, ranging from 81% to 95%. The median number of types was significantly higher in the SCC tumour (6), perilesional skin (5) and eyebrow hairs (5) than in normal skin (2). Comparing SCC tissue with other sample types within patients showed 63 overlapping infections with eyebrow hairs (71%; 95% CI: 60-80); 56 with perilesional skin samples (63%; 95% CI: 52-73) and 23 with normal skin samples (26%; 95% CI: 17-36). The sensitivity of eyebrow hair testing for detection of betaPV in the tumor was 82% (95% CI: 57-96) with concordance defined as 50% of betaPV types in common and 29% (95% CI: 10-56) for 100% concordance. These findings support the concept that perilesional skin represents an area of field change involving betaPV preceding SCC development and indicate that eyebrow hairs can serve to some degree as an easily collected marker of tumor betaPV status in epidemiological studies.

An analysis of clustering of betapapillomavirus antibodies

Betapapillomaviruses (betaPVs) may contribute to the aetiology of cutaneous squamous cell carcinoma. However, no high-risk types have yet been identified, possibly because the high frequency of co-infection prevents a straightforward analysis of the independent effects of individual viruses. This study aimed to determine whether specific virus types were more likely to co-occur than others, thereby reducing the number of parameters needed in statistical models. Antibody data were analysed from controls who participated in case-control studies in The Netherlands, Italy and Australia and from participants in the German Nutrition Survey. Cluster analysis and two ordination techniques were used to identify patterns. Evidence of clustering was found only according to the number of viruses to which antibodies were detected. The lack of clustering of specific viral types identified suggests that if there are betaPV types that are independently related to skin carcinogenesis, they are unlikely to be identified using standard epidemiological methods.

Prevalence and associated factors of betapapillomavirus infections in individuals without cutaneous squamous cell carcinoma

Betapapillomavirus (betaPV) infections are often associated with squamous-cell carcinoma (SCC) and the prevalence of betaPV infections in (immunosuppressed) SCC patients is known to be high. The distribution and possible associated factors of betaPV infections in the general population, however, are largely unknown. To address this issue, betaPV infection was studied in 1405 SCC-free immunocompetent (n=845) and immunosuppressed (n=560) individuals from six countries of different latitudes. A standard study protocol was used to obtain information about age, sex, UV-irradiation and skin type, and from all participants eyebrow hairs were collected for detection and genotyping of 25 established betaPV types using the PM-PCR reverse hybridization assay (RHA) method. The frequency of betaPV-positive participants ranged from 84 to 91 % in the immunocompetent population with HPV23 as the most prevalent type, and from 81 to 98 % in the immunosuppressed population with HPV23 as the most or the second most prevalent type. The median number of infecting betaPV types ranged from four to six in the immunocompetent and from three to six in the immunosuppressed population. Increasing age in the immunocompetent participants and (duration of) immunosuppression in the immunosuppressed patients were associated with betaPV infection. In both groups, sex, skin phototype, sunburns and sun-exposure were not consistently associated with betaPV infection. This study demonstrates that betaPV infections are also highly prevalent in SCC-free individuals, with similar HPV types prevailing in both immunocompetent and immunosuppressed persons. Age and (duration of) immunosuppression were identified as betaPV infection-associated factors, whereas characteristics related to sun exposure and skin type were not.

Functional killer Ig-like receptors on human memory CD4+ T cells specific for cytomegalovirus

Although very few CD4(+) T cells express killer Ig receptors (KIR), a large proportion of CD4(+) T cells with a late memory phenotype, characterized by the absence of CD28, does express KIR. Here, we show that KIR expression on CD4(+) T cells is also associated with memory T cell function, by showing that the frequency of CMV-specific cells is higher in CD4(+)KIR(+) than CD4(+)KIR(-) T cells. In addition, engagement of an inhibitory KIR inhibited the CMV-specific proliferation of these CD4(+)KIR(+) memory T cells, but had no detectable effect on cytokine production. Our data reveal that, in marked contrast with CD8(+) T cells, the activity of a subset of CMV-specific CD4(+) T cells is modulated by HLA class I-specific KIR. Thus, the CMV-induced down-regulation of HLA class I may in fact enhance memory CMV-specific CD4(+) T cell responses restricted by HLA class II.

Specific betapapillomaviruses associated with squamous cell carcinoma of the skin inhibit UVB-induced apoptosis of primary human keratinocytes

Epidemiological studies have shown an association between infections by specific betapapillomaviruses, such as human papillomavirus (HPV) types 5 and 8, and cutaneous squamous cell carcinoma (SCC). The role of betapapillomaviruses in the development of cutaneous SCC is, however, still enigmatic. The ability to inhibit UVB-induced apoptosis, as demonstrated for HPV5 in vitro, may be important in this respect, as survival of DNA-damaged and mutated cells increases the risk of transformation. The aim of this study was to assess whether inhibition of UVB-induced apoptosis is a general property of betapapillomaviruses and to identify apoptotic factors that are potentially involved in this process. Primary human keratinocytes transduced with E6 and E7 of selected betapapillomaviruses (HPV5, HPV8, HPV15, HPV20, HPV24 and HPV38) were characterized and subjected to UVB irradiation. HPV8- and HPV20-expressing keratinocytes in particular showed fewer signs of apoptosis, as demonstrated by lower levels of active caspase 3, less enzymic caspase activity and less DNA fragmentation. The observed inhibition of UVB-induced apoptosis was mediated by E6 and coincided with reduced steady-state expression of the pro-apoptotic protein Bax. In conclusion, E6 of HPV8 and HPV20 reduces the apoptotic responses upon UVB irradiation when expressed in primary human keratinocytes. Infections with HPV8 and HPV20 may therefore augment the carcinogenic effect of UV radiation and potentially contribute to oncogenic transformation of the skin.

Betapapillomaviruses frequently persist in the skin of healthy individuals

Infections with human papillomaviruses (HPVs) belonging to the genus Betapapillomavirus have been linked to the development of non-melanoma skin cancer. Although persistence is expected, systematic investigation of this aspect of betapapillomavirus (beta-PV) infection has not been conducted. This study investigated the prevalence and persistence of 25 known beta-PV types in the skin of immunocompetent individuals. Over a 2 year period, eight consecutive plucked eyebrow hair samples taken from 23 healthy individuals were analysed for the presence of beta-PV DNA. Using a recently published general beta-PV PCR and genotyping method, 61% of the individuals were beta-PV DNA positive for one or more types at intake, whereas during follow-up this percentage rose to 96%. HPV23 was the most frequently detected beta-PV type. Type-specific beta-PV DNA was detected over 6 months or longer in 74% of the individuals. In 57% of the individuals, DNA from multiple beta-PV types was detected simultaneously for 6 months or longer. When the detection intervals of all beta-PV type-specific infections in the study population were considered, a substantial proportion, 48%, lasted at least half a year. The consistent beta-PV patterns found over time in most individuals strongly suggested that beta-PV DNA detection in plucked eyebrow hairs reveals true beta-PV infection. If the minimum interval of detection was set at 6 months, persistent beta-PV infections were found in the majority of the study population (74%).