About

Daniel E. Ho is the William Benjamin Scott and Luna M. Scott Professor of Law, Professor of Political Science, and Professor of Computer Science (by courtesy) at Stanford University. He is also a Senior Fellow at the Stanford Institute for Human-Centered Artificial Intelligence and the Stanford Institute for Economic Policy Research. Additionally, he serves as a Senior Fellow at the Stanford Institute for Economic Policy Research and is the Director of the Regulation, Evaluation, and Governance Lab (RegLab). Ho's professional roles include serving on the National Artificial Intelligence Advisory Commission (NAIAC), advising the White House on artificial intelligence, acting as a Senior Advisor on Responsible AI at the U.S. Department of Labor, and being a Public Member of the Administrative Conference of the United States (ACUS). He holds a J.D. from Yale Law School and a Ph.D. from Harvard University, and he clerked for Judge Stephen F. Williams on the U.S. Court of Appeals, District of Columbia Circuit.

Research topics

• Medicine
• Internal medicine
• Immunology
• Pathology
• Biology
• Gastroenterology
• Microbiology
• Intensive care medicine
• Dermatology
• Virology

Selected publications

• Impending arterial thrombosis in pediatric liver transplantation: Initial experience with alteplase - A case report

  International Journal of Surgery Case Reports · 2025-07-15

  articleOpen access

  INTRODUCTION AND IMPORTANCE: Early hepatic artery thrombosis is a serious complication following pediatric liver transplantation, often associated with high morbidity and mortality. While surgical revascularization and retransplantation are the standard treatments, thrombolytic therapy has emerged as a potential alternative. However, clinical reports remain limited and standardized protocols are lacking. PRESENTATION OF CASE: A 13-month-old infant with biliary atresia post-Kasai procedure underwent living donor liver transplantation. On postoperative day 9, Doppler ultrasound detected signs of impending hepatic artery thrombosis, which was confirmed by computed tomography angiography. The patient was treated with intravenous alteplase at a dose of 0.3 mg/kg/h. After 3.5 hours of infusion, Doppler ultrasound showed improved hepatic artery flow. The infusion was stopped early due to intra-abdominal bleeding, which was managed conservatively. The patient stabilized without surgical intervention and was discharged on postoperative day 32 with stable hepatic artery flow. At six-month follow-up, the hepatic artery remained patent, and the patient was clinically stable. CLINICAL DISCUSSION: This case supports the effectiveness of alteplase administration in treating incomplete hepatic artery thrombosis, despite its bleeding risk. We recommend lower dose regimens to reduce hemorrhagic complications. However, further studies are needed to optimize the alteplase dosage. CONCLUSION: Thrombolytic therapy with alteplase is a possible and effective alternative in managing eHAT, particularly where conventional options are not indicated or limited.

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• The Evolving Landscape of Viral Infections in Immunocompromised Hosts

  Viruses · 2025-05-30 · 2 citations

  editorialOpen accessSenior author

  There has arguably never been a more dynamic and challenging time to be a clinician or researcher in the field of transplant and immunocompromised infectious diseases [...].

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• Concordance of Noninvasive Plasma Cell-free DNA With Invasive Diagnostics for Diagnosis of Invasive Fungal Disease

  Clinical Infectious Diseases · 2025-01-17 · 16 citations

  article

  BACKGROUND: Mold plasma cell-free DNA (cfDNA) polymerase chain reaction (PCR) is a promising noninvasive diagnostic modality for early diagnosis of invasive mold disease (IMD) in immunocompromised patients. Although mold cfDNA PCR has been shown to be highly accurate, the value of invasive procedures to collect specimens for conventional fungal diagnostics following plasma cfDNA testing remains unclear. METHODS: This retrospective single-center cohort study included patients with mold plasma cfDNA PCR performed 7 days before or 2 days after invasive specimen collection. Mold PCR detected Aspergillus species, Mucorales agents, Fusarium species, and Scedosporium species. Invasive procedures included tissue biopsy and bronchoscopy. The primary endpoint was the concordance of mold plasma cfDNA PCR results with results of conventional fungal tests performed on tissue and bronchoalveolar lavage fluid. RESULTS: Five hundred and six patients with mold plasma cfDNA PCR resulting ahead of invasive specimen (123 tissue and 426 bronchoalveolar lavage fluid) results were included, and 437 (86.4%) were immunocompromised. After adjudicating discordant results based on the European Organization for Research and Treatment of Cancer and Mycoses Study Group Education and Research Consortium definitions for IMD, mold plasma cfDNA PCR and invasive test results were 88.5% (448/506) concordant. In proven cases, 64.7% (11/17) of negative mold plasma cfDNA PCR results occurred in patients with fungal sinusitis (8) and limb infection (3). Nonhematologic malignancy and nonneutropenic state were statistically associated with negative mold plasma cfDNA PCR in patients with proven or probable IMD. CONCLUSIONS: Noninvasive mold plasma cfDNA PCR results were highly concordant with invasive specimen fungal test results, indicating risk-prone invasive specimen collection can be safely curtailed in immunocompromised patients with suspected IMD.

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• Treating Adenovirus Infection in Transplant Populations: Therapeutic Options Beyond Cidofovir?

  Viruses · 2025-04-23 · 8 citations

  reviewOpen accessSenior author

  Adenovirus (AdV) infections can lead to significant morbidity and increased mortality in immunocompromised populations such as hematopoietic stem cell and solid organ transplant recipients. This review evaluates currently available and emerging therapies for AdV infections. Cidofovir, while most commonly used, is limited by its variable efficacy and nephrotoxicity. This led to the development of brincidofovir, which has a better safety profile and great in vitro potency against AdV. The use of ribavirin and ganciclovir has been reported in the literature, but their use is limited due to inconsistent efficacy. Immune-based approaches, such as adoptive T-cell therapy, have shown promise in achieving viral clearance and improving survival but remain constrained by challenges related to manufacturing complexity and risks of graft-versus-host disease. This review underscores the need for standardized treatment protocols as well as comparative studies to identify optimal dosing and timing to initiate treatment. Future research should focus on individualized treatment approaches and the development of novel therapeutic agents to address the unmet clinical needs of AdV management.

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• Prevention and Treatment of Cancer-Related Infections, Version 3.2024, NCCN Clinical Practice Guidelines in Oncology

  Journal of the National Comprehensive Cancer Network · 2024-11-01 · 60 citations

  article

  There is an increased risk of infection in patients with cancer that results in higher morbidity and mortality. Several risk factors can predispose these patients to infectious complications. Some such factors include immunocompromised states like neutropenia, allogeneic hematopoietic cell transplantation, and graft-versus-host disease, while others include immunosuppressive agents like corticosteroids, purine analogs, monoclonal antibodies, and other emerging cancer therapeutics like CAR T-cell therapy. The NCCN Guidelines for the Prevention and Treatment of Cancer-Related Infections address infection concerns that may be observed in these immunocompromised populations and characterize the major pathogens to which patients with cancer are susceptible, with a focus on the prevention, diagnosis, and treatment of major common and opportunistic infections. This paper highlights 2 recently updated sections of the guidelines, namely, infection concerns related to CAR T-cell therapy and antimicrobial prophylaxis recommendations, including vaccination, in patients at high-risk for infections.

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• Dynamics and prognostic value of plasma cell-free DNA PCR in patients with invasive aspergillosis and mucormycosis

  Journal of Clinical Microbiology · 2024-04-11 · 22 citations

  articleOpen access

  ABSTRACT Aspergillus species and Mucorales agents are the primary etiologies of invasive fungal disease (IFD). Biomarkers that predict outcomes are needed to improve care. Patients diagnosed with invasive aspergillosis and mucormycosis using plasma cell-free DNA (cfDNA) PCR were retested weekly for 4 weeks. The primary outcome included all-cause mortality at 6 weeks and 6 months based on baseline cycle threshold (CT) values and results of follow-up cfDNA PCR testing. Forty-five patients with Aspergillus and 30 with invasive Mucorales infection were retested weekly for a total of 197 tests. Using the European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium (EORTC/MSG) criteria, 30.7% (23/75), 25.3% (19/75), and 38.7% (29/75) had proven, probable, and possible IFD, respectively. In addition, 97.3% (73/75) were immunocompromised. Baseline CT increased significantly starting at week 1 for Mucorales and week 2 for Aspergillus . Aspergillosis and mucormycosis patients with higher baseline CT (CT >40 and >35, respectively) had a nonsignificantly higher survival rate at 6 weeks, compared with patients with lower baseline CT. Mucormycosis patients with higher baseline CT had a significantly higher survival rate at 6 months. Mucormycosis, but not aspergillosis patients, with repeat positive cfDNA PCR results had a nonsignificantly lower survival rate at 6 weeks and 6 months compared with patients who reverted to negative. Aspergillosis patients with baseline serum Aspergillus galactomannan index <0.5 and <1.0 had significantly higher survival rates at 6 weeks when compared with those with index ≥0.5 and ≥1.0, respectively. Baseline plasma cfDNA PCR CT can potentially be used to prognosticate survival in patients with invasive Aspergillus and Mucorales infections. IMPORTANCE We show that Aspergillus and Mucorales plasma cell-free DNA PCR can be used not only to noninvasively diagnose patients with invasive fungal disease but also to correlate the baseline cycle threshold with survival outcomes, thus potentially allowing the identification of patients at risk for poor outcomes, who may benefit from more targeted therapies.

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• Neuroinvasive <i>Francisella tularensis</i> Infection: Report of 2 Cases and Review of the Literature

  Clinical Infectious Diseases · 2024-01-31 · 5 citations

  articleOpen access

  BACKGROUND: Neuroinvasive infection with Francisella tularensis, the causative agent of tularemia, is rare. Establishing clinical suspicion is challenging if risk factors or clinical features classically associated with tularemia are absent. Tularemia is treatable with antibiotics; however, there are limited data to inform management of potentially fatal neuroinvasive infection. METHODS: We collected epidemiologic and clinical data on 2 recent US cases of neuroinvasive F. tularensis infection, and performed a literature review of cases of neuroinvasive F. tularensis infection published after 1950. RESULTS: One patient presented with focal neurologic deficits and brain lesions; broad-range molecular testing on resected brain tissue detected F. tularensis. The other patient presented with meningeal signs; tularemia was suspected based on animal exposure, and F. tularensis grew in cerebrospinal fluid (CSF) culture. Both patients received combination antibiotic therapy and recovered from infection. Among 16 published cases, tularemia was clinically suspected in 4 cases. CSF often displayed lymphocytic pleocytosis. Among cases with available data, CSF culture was positive in 13 of 16 cases, and F. tularensis antibodies were detected in 11 of 11 cases. Treatment typically included an aminoglycoside combined with either a tetracycline or a fluoroquinolone. Outcomes were generally favorable. CONCLUSIONS: Clinicians should consider neuroinvasive F. tularensis infection in patients with meningitis and signs suggestive of tularemia or compatible exposures, lymphocyte-predominant CSF, unrevealing standard microbiologic workup, or lack of response to empiric bacterial meningitis treatment. Molecular testing, culture, and serologic testing can reveal the diagnosis. Favorable outcomes can be achieved with directed antibiotic treatment.

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• Managing infectious challenges in the age of molecular‐targeted therapies for adult hematological malignancies

  Transplant Infectious Disease · 2024-05-02 · 1 citations

  articleOpen access

  Over the last decade, the therapeutic landscape for hematological malignancies (HMs) has witnessed a remarkable surge in the development of novel biological and small-molecule-targeted immunomodulatory agents. These therapies have drastically improved survival, but some come at the cost of increased risk of bacterial, viral, and/or fungal infections and on-target off-tumor immunological side effects. To mitigate such risks, physicians must be well informed about infectious complications and necessary preventive measures, such as screening, vaccinations, and antimicrobial prophylaxis. Furthermore, physicians should be vigilant about the noninfectious side effects of these agents that can mimic infections and understand their potential drug-drug interactions with antimicrobials. Strengthening and harmonizing the current surveillance and reporting system for drug-associated infections in real-world settings is essential to better ascertain the potential infections associated with these agents. In this review, we aimed to summarize the infection risks associated with novel agents used for specific HMs and outline recommended strategies for monitoring and prophylaxis.

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• Case Report: Relapsing Leptospirosis in an Immunocompromised Host

  American Journal of Tropical Medicine and Hygiene · 2023-08-21 · 3 citations

  articleOpen access

  Leptospirosis is typically a self-limited febrile illness; when it occurs, meningitis usually develops early in the course. Here, we describe a patient who had engaged in freshwater activities in Kauai that was immunocompromised due to a history of mantle cell lymphoma, autologous hematopoietic cell transplant, and hypogammaglobulinemia. He developed leptospiral meningoencephalitis 11 weeks after illness onset and persistently detectable Leptospira DNA in blood and cerebrospinal fluid along with ongoing clinical illness, despite appropriate treatment.

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• Erythema Gyratum Repens Secondary to Pulmonary Tuberculosis

  Annals of Internal Medicine · 2023-03-13 · 1 citations

  letterSenior author

  Letters14 March 2023Erythema Gyratum Repens Secondary to Pulmonary TuberculosisCaitlin A. Contag, MD, Nolan Maloney, MD, Ralph Tayyar, MD, Maria Alexandrova Aleshin, MD, Roberto Andres Novoa, MD, Dora Yukwai Ho, MD, PhDCaitlin A. Contag, MDDivision of Infectious Diseases & Geographic Medicine, Department of Medicine, Stanford University, Stanford, CaliforniaSearch for more papers by this author, Nolan Maloney, MDDepartment of Dermatology, Stanford University, Stanford, CaliforniaSearch for more papers by this author, Ralph Tayyar, MDDivision of Infectious Diseases & Geographic Medicine, Department of Medicine, Stanford University, Stanford, CaliforniaSearch for more papers by this author, Maria Alexandrova Aleshin, MDDepartment of Dermatology, Stanford University, Stanford, CaliforniaSearch for more papers by this author, Roberto Andres Novoa, MDDepartment of Dermatology and Department of Pathology, Stanford University, Stanford, CaliforniaSearch for more papers by this author, Dora Yukwai Ho, MD, PhDDivision of Infectious Diseases & Geographic Medicine, Department of Medicine, Stanford University, Stanford, CaliforniaSearch for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/L22-0453 SectionsAboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail Background: Erythema gyratum repens (EGR) is a striking dermatologic phenomenon associated with underlying malignancy in approximately 70% of cases (1). However, in the remaining 30% of cases, underlying etiologies are broad, from cutaneous immune deposition associated with autoimmune diseases to messenger RNA–based vaccines against COVID-19 (2, 3). Sometimes no underlying cause can be identified. Rarely tuberculosis (TB) has been reported as a possible trigger (4). However, the relationship between EGR and TB has not been well documented. Here, we report a case of EGR associated with pulmonary TB.Objective: To describe an unusual cutaneous complication of TB to help facilitate ...References1. Rongioletti F, Fausti V, Parodi A. Erythema gyratum repens is not an obligate paraneoplastic disease: a systematic review of the literature and personal experience. J Eur Acad Dermatol Venereol. 2014;28:112-5. [PMID: 22830929] doi:10.1111/j.1468-3083.2012.04663.x CrossrefMedlineGoogle Scholar2. Sussman M, Zhai L, Morquette A, et al. Annular bullous diseases. Clin Dermatol. 2022;40:516-28. [PMID: 34979265] doi:10.1016/j.clindermatol.2021.12.012 CrossrefMedlineGoogle Scholar3. Niebel D, Wilhelmi J, De Vos L, et al. Annular plaques mimicking Rowell's syndrome in the course of coronavirus disease 2019 mRNA vaccines: an overlooked phenomenon. J Dermatol. 2022;49:151-6. [PMID: 34693548] doi:10.1111/1346-8138.16210 CrossrefMedlineGoogle Scholar4. Barber PV, Doyle L, Vickers DM, et al. Erythema gyratum repens with pulmonary tuberculosis. Br J Dermatol. 1978;98:465-8. [PMID: 638054] doi:10.1111/j.1365-2133.1978.tb06543.x CrossrefMedlineGoogle Scholar5. Takwoingi Y, Whitworth H, Rees-Roberts M, et al. Interferon gamma release assays for Diagnostic Evaluation of Active tuberculosis (IDEA): test accuracy study and economic evaluation. Health Technol Assess. 2019;23:1-152. [PMID: 31138395] doi:10.3310/hta23230 CrossrefMedlineGoogle Scholar Author, Article, and Disclosure InformationAuthors: Caitlin A. Contag, MD; Nolan Maloney, MD; Ralph Tayyar, MD; Maria Alexandrova Aleshin, MD; Roberto Andres Novoa, MD; Dora Yukwai Ho, MD, PhDAffiliations: Division of Infectious Diseases & Geographic Medicine, Department of Medicine, Stanford University, Stanford, CaliforniaDepartment of Dermatology, Stanford University, Stanford, CaliforniaDepartment of Dermatology and Department of Pathology, Stanford University, Stanford, CaliforniaDisclosures: Disclosures can be viewed at www.acponline.org/authors/icmje/ConflictOfInterestForms.do?msNum=L22-0453.Corresponding Author: Caitlin A. Contag, MD, Division of Infectious Diseases & Geographic Medicine, Department of Medicine, Stanford University, 300 Pasteur Drive, L-134, Stanford, CA 94304; e-mail, cacontag@stanford.edu.This article was published at Annals.org on 14 March 2023. PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetails Metrics May 2023Volume 176, Issue 5Page: 733-735KeywordsAutoimmune diseasesBiopsyDermatologyErythemaEtiologyInfectious diseasesLesionsLungsRashesTuberculosis ePublished: 14 March 2023 Issue Published: May 2023 Copyright & PermissionsCopyright © 2023 by American College of Physicians. All Rights Reserved.PDF downloadLoading ...

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Frequent coauthors

• Robert M. Sapolsky

  Stanford University

  56 shared

• Sheri Fink

  34 shared

• Gary K. Steinberg

  Stanford Medicine

  32 shared

• Midori A. Yenari

  University of California, San Francisco

  32 shared

• Thomas Ringer

  Jena University Hospital

  26 shared

• Zhijian Zhang

  Huaqiao University

  26 shared

• Matthew S Lawrence

  Virscio (United States)

  15 shared

• Niaz Banaei

  Stanford University

  14 shared

Awards & honors

• Faculty Fellow at the Center for Advanced Study in the Behav…
• Director of the Regulation, Evaluation, and Governance Lab (…
• Member of the National Artificial Intelligence Advisory Comm…
• Senior Advisor on Responsible AI at the U.S. Department of L…
• Public Member of the Administrative Conference of the United…