The Growing Role of Digital Health Tools in the Care of Patients with Cancer: Current Use, Future Opportunities, and Barriers to Effective Implementation.

PURPOSE OF REVIEW: This article aims to describe the ways in which digital health technologies are currently being used to improve the delivery of cancer care, highlight opportunities to expand their use, and discuss barriers to effective and equitable implementation. RECENT FINDINGS: The utilization of digital health tools and development of novel care delivery models that leverage such tools is expanding. Recent studies have shown feasibility and increased implementation in the setting of oncologic care. With technological advances and key policy changes, utilization of digital health tools has greatly increased over the past two decades and transformed how cancer care is delivered. As digital health tools are expanded and refined, there is potential for improved access to and quality and efficiency of cancer care. However, careful consideration should be given to key barriers of digital health tool adoption, such as infrastructural, patient-level, and health systems-level challenges, to ensure equitable access to care and improvement in health outcomes.

Examining crossover and postprotocol therapies in first-line immunotherapy trials in non-small cell lung cancer (NSCLC).

BACKGROUND: Immune checkpoint inhibitor (ICI) therapy has led to significant improvement in outcomes for patients with nononcogene-driven advanced non-small cell lung cancer (NSCLC). The rate of crossover and receipt of postprotocol ICI in frontline trials for advanced NSCLC has not been systematically evaluated. METHODS: ClinicalTrials.gov was used to identify phase 3 studies evaluating the use of immunotherapy or combination chemoimmunotherapy against chemotherapy alone in the frontline management of advanced NSCLC. Data on outcomes, rate of crossover and/or subsequent post-protocol receipt of immunotherapy, and the start dates of these clinical trials were then extracted. RESULTS: Twenty-three frontline trials in nononcogene-driven advanced NSCLC were identified. Six trials with ICI monotherapy/dual ICI therapy and 17 trials evaluating chemotherapy/ICI in first-line advanced NSCLC were included in the analysis. The crossover rate ranged 0% to 54% in ICI monotherapy/dual ICI trials and 0% to 52% in chemotherapy/ICI trials. Nineteen of 23 trials provided information on subsequent postprotocol therapies. Among the trials not allowing crossover, postprotocol ICI was administered to 17% to 45.8% of patients. Information regarding the eventual receipt of ICI therapy was available for 22 of 23 trials. Of 6631 patients, 2507 (37.8%) randomized to the control arm eventually received ICI therapy. CONCLUSION: The rate of crossover and postprotocol ICI use was low in frontline trials for first-line NSCLC incorporating ICI. Given the proven survival overall survival of ICI in a broad population, there is a need to ensure availability of this life-prolonging therapy in future trials, either by crossover treatment or postprotocol administration.

T-cell phenotype including CD57+ T follicular helper cells in the tumor microenvironment correlate with a poor outcome in follicular lymphoma.

T-lymphocytes are prevalent in the tumor microenvironment of follicular lymphoma (FL). However, the phenotype of T-cells may vary, and the prevalence of certain T-cell subsets may influence tumor biology and patient survival. We therefore analyzed a cohort of 82 FL patients using CyTOF to determine whether specific T-cell phenotypes were associated with distinct tumor microenvironments and patient outcome. We identified four immune subgroups with differing T-cell phenotypes and the prevalence of certain T-cell subsets was associated with patient survival. Patients with increased T cells with early differentiation stage tended to have a significantly better survival than patients with increased T-cells of late differentiation stage. Specifically, CD57+ TFH cells, with a late-stage differentiation phenotype, were significantly more abundant in FL patients who had early disease progression and therefore correlated with an inferior survival. Single cell analysis (CITE-seq) revealed that CD57+ TFH cells exhibited a substantially different transcriptome from CD57- TFH cells with upregulation of inflammatory pathways, evidence of immune exhaustion and susceptibility to apoptosis. Taken together, our results show that different tumor microenvironments among FL patients are associated with variable T-cell phenotypes and an increased prevalence of CD57+ TFH cells is associated with poor patient survival.

Patient- and Provider-Level Factors Associated With Telehealth Utilization Across a Multisite, Multiregional Cancer Practice From 2019 to 2021.

PURPOSE: In response to the COVID-19 pandemic, many cancer practices rapidly adopted telehealth services. However, there is a paucity of data regarding ongoing telehealth visit utilization beyond this initial response. The purpose of this study was to assess changes in variables associated with telehealth visit utilization over time. METHODS: This is a cross-sectional, year-over-year, retrospective analysis of telehealth visits conducted across a multisite, multiregional cancer practice in the United States. Multivariable models examined the association of patient- and provider-level variables with telehealth utilization across outpatient visits conducted over three 8-week periods from July to August in 2019 (n = 32,537), 2020 (n = 33,399), and 2021 (n = 35,820). RESULTS: The rate of telehealth utilization increased from <0.01% (2019) to 11% (2020) to 14% (2021). The most significant patient-level factors associated with increased telehealth utilization included nonrural residence and age ≤65 years. Among patients residing in rural settings, video visit utilization rates were significantly lower and phone visit utilization rates were significantly higher compared with patients from nonrural residences. Regarding provider-level factors, widening differences in telehealth utilization were observed at tertiary versus community-based practice settings. Increased telehealth utilization was not associated with duplicative care as per-patient and per-physician visit volumes in 2021 remained consistent with prepandemic levels. CONCLUSION: We observed continuous expansion in telehealth visit utilization from 2020 to 2021. Our experiences suggest that telehealth can be integrated into cancer practices without evidence of duplicative care. Future work should examine sustainable reimbursement structures and policies to ensure accessibility of telehealth as a means to facilitate equitable, patient-centered cancer care.

Patient-Reported Outcomes, Digital Health, and the Quest to Improve Health Equity.

The theme of the 2023 American Society of Clinical Oncology Annual Meeting is Partnering With Patients: The Cornerstone of Cancer Care and Research. As we aim to partner with patients to improve their health care, digital tools have the potential to enhance patient-centered cancer care and make clinical research more accessible and generalizable. Using electronic patient-reported outcomes (ePROs) to collect patients' reports of symptoms, functioning, and well-being facilitates patient-clinician communication and improves care and outcomes. Early studies suggest that racial and ethnic minority populations, older patients, and patients with less education may benefit even more from ePRO implementation. Clinical practices looking to implement ePROs can refer to the resources of the PROTEUS Consortium (Patient-Reported Outcomes Tools: Engaging Users & Stakeholders). Beyond ePROs, in response to the COVID-19 pandemic, cancer practices have rapidly adopted other digital tools (eg, telemedicine, remote patient monitoring). As implementation grows, we must be aware of the limitations of these tools and implement them in ways to promote optimal function, access, and ease of use. Infrastructure, patient, provider, and system-level barriers need to be addressed. Partnerships across all levels can inform development and implementation of digital tools to meet the needs of diverse groups. In this article, we describe how we use ePROs and other digital health tools in cancer care, how digital tools can expand access to and generalizability of oncology care and research, and prospects for broader implementation and use.

Characterization of immune exhaustion and suppression in the tumor microenvironment of splenic marginal zone lymphoma.

The role of the tumor microenvironment (TME) and intratumoral T cells in splenic marginal zone lymphoma (sMZL) is largely unknown. In the present study, we evaluated 36 sMZL spleen specimens by single cell analysis to gain a better understanding of the TME in sMZL. Using mass cytometry (CyTOF), we observed that the TME in sMZL is distinct from that of control non-malignant reactive spleen (rSP). We found that the number of TFH cells varied greatly in sMZL, ICOS+ TFH cells were more abundant in sMZL than rSP, and TFH cells positively correlated with increased numbers of memory B cells. Treg cell analysis revealed that TIGIT+ Treg cells are enriched in sMZL and correlate with suppression of TH17 and TH22 cells. Intratumoral CD8+ T cells were comprised of subsets of short-lived, exhausted and late-stage differentiated cells, thereby functionally impaired. We observed that T-cell exhaustion was present in sMZL and TIM-3 expression on PD-1low cells identified cells with severe immune dysfunction. Gene expression profiling by CITE-seq analysis validated this finding. Taken together, our data suggest that the TME as a whole, and T-cell population specifically, are heterogenous in sMZL and immune exhaustion is one of the major factors impairing T-cell function.

Impact of a High-Risk, Ambulatory COVID-19 Remote Patient Monitoring Program on Utilization, Cost, and Mortality.

OBJECTIVE: To evaluate care utilization, cost, and mortality among high-risk patients enrolled in a coronavirus disease 2019 (COVID-19) remote patient monitoring (RPM) program. METHODS: This retrospective analysis included patients diagnosed with COVID-19 at risk for severe disease who enrolled in the RPM program between March 2020 and October 2021. The program included in-home technology for symptom and physiologic data monitoring with centralized care management. Propensity score matching established matched cohorts of RPM-engaged (defined as ≥1 RPM technology interactions) and non-engaged patients using a logistic regression model of 59 baseline characteristics. Billing codes and the electronic death certificate system were used for data abstraction from the electronic health record and reporting of care utilization and mortality endpoints. RESULTS: Among 5796 RPM-enrolled patients, 80.0% engaged with the technology. Following matching, 1128 pairs of RPM-engaged and non-engaged patients comprised the analysis cohorts. Mean patient age was 63.3 years, 50.9% of patients were female, and 81.9% were non-Hispanic White. Patients who were RPM-engaged experienced significantly lower rates of 30-day, all-cause hospitalization (13.7% vs 18.0%, P=.01), prolonged hospitalization (3.5% vs 6.7%, P=.001), intensive care unit admission (2.3% vs 4.2%, P=.01), and mortality (0.5% vs 1.7%; odds ratio, 0.31; 95% CI, 0.12 to 0.78; P=.01), as well as cost of care ($2306.33 USD vs $3565.97 USD, P=0.04), than those enrolled in RPM but non-engaged. CONCLUSION: High-risk COVID-19 patients enrolled and engaged in an RPM program experienced lower rates of hospitalization, intensive care unit admission, mortality, and cost than those enrolled and non-engaged. These findings translate to improved hospital bed access and patient outcomes.

Development and initial cognitive testing of the Digital Equity Screening Tool (DEST): Community participatory approach to assessing digital inequality.

COVID-19 has widened the existing digital divide, especially for people from socially and economically deprived communities. We describe a program evaluation using a community participatory approach to develop self-reported items of patient experience with technology inclusive of digital access and literacy. The feedback received from Community Advisory Boards and Community Engagement Studio members led to the evaluation and refinement of the individual items. The community-based participatory approach highlighted in our paper to develop these items could serve as a model for other screening tool development for enhancing equity and inclusiveness in clinical care and research.

Economic Cost and Sustainability of Oral Therapies in Precision Oncology.

PURPOSE: Precision oncology promises improved outcomes but the cost-effectiveness and accessibility of targeted therapies is debatable. We report price change patterns from 2015 to 2019 for several oral anticancer medications for common solid tumor malignancies. METHODS: We collected provider utilization and payment data from the public Medicare Part D database and extracted drug price information for commonly prescribed targeted oral anticancer agents for lung, breast, and prostate cancer. We then calculated median Pearson correlation coefficient values for various drugs (containing more than two data points) within each therapeutic class. We also calculated compound annual growth rates (CAGRs) for medication costs within each class and compared them with the consumer price index (CPI). RESULTS: Our study included six epidermal growth factor receptor inhibitors (EGFRi; one generic), five anaplastic lymphoma kinase inhibitors (ALKi), two B-Raf inhibitors (BRAFi), three hormonal agents (one generic), three cyclin-dependent kinases 4 and 6 inhibitors (CDK4/6i), two poly-ADP-ribose inhibitors (PARPi), and seven antiandrogen agents (two generic). The median (range) Pearson correlation coefficient values for cost of drugs within each therapeutic class were 0.967 (0.915-0.978) for EGFRi, 0.981 (0.966-0.989) for ALKi, 0.996 for BRAFi, 0.994 (0.992-0.999) for CDK4/6i, 0.855 for PARPi, and 0.442 (-0.522 to 0.962) for antiandrogens. Therapies with two or fewer data points (generic erlotinib, dacomitinib, abiraterone, apalutamide, and darolutamide) were excluded. The median CAGRs in costs over the 5-year period were 4.56% (EGFRi), 6.40% (ALKi), 2.58% (BRAFi), 5.48% (hormonal agents), 5.21% (CDK4/6i), 27.29% (PARPi), and 34.8% (antiandrogens). The CPI over 5 years was 2.26%/year, and the average inflation rate was 1.90%/year. CONCLUSION: The median CAGR in costs for modern oral precision-driven cancer therapeutic classes mostly outpaced CPI and the average inflation. Increase in cost within the same class should be weighed against incremental clinical benefit for the patients to ensure that rising costs do not limit access to targeted therapies.

High-dimensional and single-cell transcriptome analysis of the tumor microenvironment in angioimmunoblastic T cell lymphoma (AITL).

Angioimmunoblastic T-cell lymphoma (AITL) is an aggressive lymphoid malignancy associated with a poor clinical prognosis. The AITL tumor microenvironment (TME) is unique, featuring a minority population of malignant CD4+ T follicular helper (TFH) cells inter-mixed with a diverse infiltrate of multi-lineage immune cells. While much of the understanding of AITL biology to date has focused on characteristics of the malignant clone, less is known about the many non-malignant populations that comprise the TME. Recently, mutational consistencies have been identified between malignant cells and non-malignant B cells within the AITL TME. As a result, a significant role for non-malignant populations in AITL biology has been increasingly hypothesized. In this study, we have utilized mass cytometry and single-cell transcriptome analysis to identify several expanded populations within the AITL TME. Notably, we find that B cells within the AITL TME feature decreased expression of key markers including CD73 and CXCR5. Furthermore, we describe the expansion of distinct CD8+ T cell populations that feature an exhausted phenotype and an underlying expression profile indicative of dysfunction, impaired cytotoxicity, and upregulation of the chemokines XCL2 and XCL1.

Expression of KLRG1 and CD127 defines distinct CD8+ subsets that differentially impact patient outcome in follicular lymphoma.

BACKGROUND: CD8+ T-lymphocyte subsets defined by killer lectin-like receptor G1 (KLRG1) and CD127 expression have been reported to have an important role in infection, but their role in the setting of lymphoid malignancies, specifically follicular lymphoma (FL), has not been studied. METHODS: To characterize the phenotype of KLRG1/CD127-defined CD8+ subsets, surface and intracellular markers were measured by flow cytometry and Cytometry by time of flight (CyTOF), and the transcriptional profile of these cells was determined by CITE-Seq (Cellular Indexing of Transcriptomes and Epitopes by Sequencing). The functional capacity of each subset was determined, as was their impact on overall survival (OS) and event-free survival (EFS) of patients with FL. RESULTS: We found that intratumoral CD8+ cells in FL are skewed toward effector cell subsets, particularly KLRG+CD127- and KLRG1-CD127- cells over memory cell subsets, such as KLRG1-CD127+ and KLRG1+CD127+ cells. While effector subsets exhibited increased capacity to produce cytokines/granules when compared with memory subsets, their proliferative capacity and viability were found to be substantially inferior. Clinically, a skewed distribution of intratumoral CD8+ T cells favoring effector subtypes was associated with an inferior outcome in patients with FL. Increased numbers of CD127+KLRG1- and CD127+KLRG1+ were significantly associated with a favorable OS and EFS, while CD127-KLRG1- correlated with a poor EFS and OS in patients with FL. Furthermore, we demonstrated that interleukin (IL)-15 promotes CD127-KLRG1+ cell development in the presence of dendritic cells via a phosphoinositide 3-kinase (PI3K)-dependent mechanism, and treatment of CD8+ T cells with a PI3K inhibitor downregulated the transcription factors responsible for CD127-KLRG1+ differentiation. CONCLUSIONS: Taken together, these results reveal not only a biological and prognostic role for KLRG1/CD127-defined CD8+ subsets in FL but also a potential role for PI3K inhibitors to manipulate the differentiation of CD8+ T cells, thereby promoting a more effective antitumor immune response.

Association of a Remote Patient Monitoring (RPM) Program With Reduced Hospitalizations in Cancer Patients With COVID-19.

PURPOSE: The goal of this study was to assess the impact of an interdisciplinary remote patient monitoring (RPM) program on clinical outcomes and acute care utilization in cancer patients with COVID-19. METHODS: This is a cross-sectional analysis following a prospective observational study performed at Mayo Clinic Cancer Center. Adult patients receiving cancer-directed therapy or in recent remission on active surveillance with polymerase chain reaction-confirmed SARS-CoV-2 infection between March 18 and July 31, 2020, were included. RPM was composed of in-home technology to assess symptoms and physiologic data with centralized nursing and physician oversight. RESULTS: During the study timeframe, 224 patients with cancer were diagnosed with COVID-19. Of the 187 patients (83%) initially managed in the outpatient setting, those who did not receive RPM were significantly more likely to experience hospitalization than those receiving RPM. Following balancing of patient characteristics by inverse propensity score weighting, rates of hospitalization for RPM and non-RPM patients were 2.8% and 13%, respectively, implying that the use of RPM was associated with a 78% relative risk reduction in hospital admission rate (95% CI, 54 to 102; P = .002). Furthermore, when hospitalized, these patients experienced a shorter length of stay and fewer prolonged hospitalizations, intensive care unit admissions, and deaths, although these trends did not reach statistical significance. CONCLUSION: The use of RPM and a centralized virtual care team was associated with a reduction in hospital admission rate and lower overall acute care resource utilization among cancer patients with COVID-19.

HHV-6B infection, T-cell reconstitution, and graft-vs-host disease after hematopoietic stem cell transplantation.

Successful and sustained CD4+ T-cell reconstitution is associated with increased survival after hematopoietic cell transplantation (HCT), but opportunistic infections may adversely affect the time and extent of immune reconstitution. Human herpesvirus 6B (HHV-6B) efficiently infects CD4+ T cells and utilizes as a receptor CD134 (OX40), a member of the TNF superfamily that antagonizes regulatory T-cell (Treg) activity. Reactivation of HHV-6B has been associated with aberrant immune reconstitution and acute graft-versus-host disease (aGVHD) after HCT. Given that Treg counts are negatively correlated with aGVHD severity, we postulate that one mechanism for the poor CD4+ T-cell reconstitution observed shortly after transplant may be HHV-6B infection and depletion of peripheral (extra-thymic) CD4+ T cells, including a subpopulation of Treg cells. In turn, this may trigger a series of adverse events resulting in poor clinical outcomes such as severe aGVHD. In addition, recent evidence has linked HHV-6B reactivation with aberrant CD4+ T-cell reconstitution late after transplantation, which may be mediated by a different mechanism, possibly related to central (thymic) suppression of T-cell reconstitution. These observations suggest that aggressive management of HHV-6B reactivation in transplant patients may facilitate CD4+ T-cell reconstitution and improve the quality of life and survival of HCT patients.

CD4+ T Cells Coexpressing CD134 (OX40) Harbor Significantly Increased Levels of Human Herpesvirus 6B DNA Following Umbilical Cord Blood Transplantation.

Human herpesvirus 6B (HHV-6B) commonly reactivates after umbilical cord blood transplantation (UCBT) and is associated with delayed engraftment, fever, rash, and central nervous system dysfunction. Recently, CD134 (OX40) has been implicated as a potential viral entry receptor. We evaluated CD4+CD134+/neg-lo and CD8+CD134+/neg-lo cells at day 28 after UCBT in 20 subjects with previously documented HHV-6 reactivation and persistent viremia. Analysis of CD4+CD134+ cells as compared to CD4+CD134neg-lo cells showed 0.308 versus 0.129 copies of HHV-6B/cell (P = .0002). CD8+CD134+/neg-lo cells contained little to no HHV-6B copies. Following UCBT, CD4+CD134+ cells harbor significantly increased levels of HHV-6B, suggesting that CD134 (OX40) may facilitate viral entry.

Classification of HHV-6A and HHV-6B as distinct viruses.

Shortly after the discovery of human herpesvirus 6 (HHV-6), two distinct variants, HHV-6A and HHV-6B, were identified. In 2012, the International Committee on Taxonomy of Viruses (ICTV) classified HHV-6A and HHV-6B as separate viruses. This review outlines several of the documented epidemiological, biological, and immunological distinctions between HHV-6A and HHV-6B, which support the ICTV classification. The utilization of virus-specific clinical and laboratory assays for distinguishing HHV-6A and HHV-6B is now required for further classification. For clarity in biological and clinical distinctions between HHV-6A and HHV-6B, scientists and physicians are herein urged, where possible, to differentiate carefully between HHV-6A and HHV-6B in all future publications.

Immunomodulation and immunosuppression by human herpesvirus 6A and 6B.

Like other members of the Herpesviridae family, human herpesvirus (HHV)-6A and HHV-6B have developed a wide variety of strategies to modulate or suppress host immune responses and, thereby, facilitate their own spread and persistence in vivo. Long considered two variants of the same virus, HHV-6A and HHV-6B have recently been reclassified as distinct viral species, although the established nomenclature has been maintained. In this review, we summarize the distinctive profiles of interaction of these two viruses with the human immune system. Both HHV-6A and HHV-6B display a tropism for CD4+ T lymphocytes, but they can also infect, in a productive or nonproductive fashion, other cells of the immune system. However, there are important differences regarding the ability of each virus to infect cytotoxic effector cells, as HHV-6A has been shown to productively infect several of these cells, whereas HHV-6B infects them inefficiently at best. In addition to direct cytopathic effects, both HHV-6A and HHV-6B can interfere with immunologic functions to varying degrees via cytokine modulation, including blockade of IL-12 production by professional antigen-presenting cells, modulation of cell-surface molecules essential for T-cell activation, and expression of viral chemokines and chemokine receptors. Some of these effects are related to signaling through and downregulation of the viral receptor, CD46, a key molecule linking innate and adaptive immune responses. Increasing attention has recently been focused on the importance of viral interactions with dendritic cells, which may serve both as targets of virus-mediated immunosuppression and as vehicles for viral transfer to CD4+ T cells. Our deepening knowledge of the mechanisms developed by HHV-6A and HHV-6B to evade immunologic control may lead to new strategies for the prevention and treatment of the diseases associated with these viruses. Moreover, elucidation of these viral mechanisms may uncover new avenues to therapeutically manipulate or modulate the immune system in immunologically mediated human diseases.

Persistent human herpesvirus-6 infection in patients with an inherited form of the virus.

Human herpesvirus-6 (HHV-6)A and 6B are ubiquitous betaherpesviruses viruses with lymphotropic and neurotropic potential. As reported earlier, these viruses establish latency by integration into the telomeres of host chromosomes. Chromosomally integrated HHV-6 (CIHHV-6) can be transmitted vertically from parent to child. Some CIHHV-6 patients are suffering from neurological symptoms, while others remain asymptomatic. Four patients with CIHHV-6 and CNS dysfunction were treated with valganciclovir or foscarnet. HHV-6 replication was detected by reverse transcriptase polymerase chain reaction amplification of a late envelope glycoprotein. In this study we also compared the inherited and persistent HHV-6 viruses by DNA sequencing. The prevalence of CIHHV-6 in this cohort of adult patients from the USA suffering from a wide range of neurological symptoms including long-term fatigue were found significantly greater than the reported 0.8% in the general population. Long-term antiviral therapy inhibited HHV-6 replication as documented by loss of viral mRNA production. Sequence comparison of the mRNA and the inherited viral genome revealed that the transcript is produced by an exogenous virus. In conclusion, the data presented here document that some individuals with CIHHV-6 are infected persistently with exogenous HHV-6 strains that lead to a wide range of neurological symptoms; the proposed name for this condition is inherited herpesvirus 6 syndrome or IHS.

Antiviral therapy of two patients with chromosomally-integrated human herpesvirus-6A presenting with cognitive dysfunction.

BACKGROUND: Human herpesvirus 6 (HHV-6) is a neurotropic virus implicated in central nervous system (CNS) dysfunction, multiple sclerosis, seizures and encephalitis. Inherited or "chromosomally integrated" HHV-6 (CIHHV-6) is a condition characterized by high DNA loads and germ line transmission of HHV-6 genomes, which are integrated into the telomere. OBJECTIVES: We previously reported that integrated HHV-6 can be reactivated by trichostatin A in vitro. Therefore, we hypothesized that a broad array of neurological symptoms of CIHHV-6 patients may respond to antiviral drug treatment. STUDY DESIGN: The patients have been treated with antiviral drugs and monitored for viral load, late mRNA, and clinical improvement. RESULTS: Antiviral therapy of two CIHHV patients resulted in successful clinical resolution. However, both patients relapsed on multiple occasions within 4-6 months of cessation of antiviral therapy. CONCLUSIONS: Successful antiviral drug treatment suggests that clinical symptoms of these patients were due to symptomatic reactivation of CIHHV-6. Alternatively, some CIHHV-6 patients may have a reduced resistance to community-acquired HHV-6 strains due to tolerance leading to persistent infections.

The Link between Hypersensitivity Syndrome Reaction Development and Human Herpes Virus-6 Reactivation.

Background. There are challenges in the clinical diagnosis of drug-induced injury and in obtaining information on the reactivation of human herpes viruses (HHV) during idiosyncratic adverse drug reactions. Objectives. (i) To develop a unified list of drugs incriminated in drug-induced hepatotoxicity and severe cutaneous reactions, in which drug hypersensitivity leads to HHV-6 reactivation and further complication of therapy and recovery and (ii) to supplement the already available data on reporting frequencies of liver- or skin-induced cases with knowledge of individual case reports, including HHV-6 reactivation and briefly introducing chromosomally integrated HHV-6. Data Sources and Extraction. Drugs identified as causes of (i) idiosyncratic reactions, (ii) drug-induced hypersensitivity, drug-induced hepatotoxicity, acute liver failure, and Stevens-Johnson syndrome, and (iii) human herpes virus reactivation in PubMed since 1997 have been collected and discussed. Results. Data presented in this paper show that HHV-6 reactivation is associated with more severe organ involvement and a prolonged course of disease. Conclusion. This analysis of HHV-6 reactivation associated with drug-induced severe cutaneous reactions and hepatotoxicity will aid in causality assessment and clinical diagnosis of possible life-threatening events and will provide a basis for further patient characterization and therapy.