Tom C Quach

All Publications

• Digital Biometric Measures in Long COVID: A Secondary Analysis of the STOP-PASC Randomized Clinical Trial. JAMA network open Gunturkun, F., Hedlin, H., Botzheim, B., Deng, Y., Bonilla, H., Jagannathan, P., Quach, T. C., Kim, S., Lin, M., O'Riordan, G., Tzeng, H., Adamowicz, L., Demanuele, C., Cai, X., Yang, P. C., Singh, U., Geng, L. N. 2025; 8 (8): e2526901

  Abstract

  Digital biometrics can be used to monitor disease, but there is limited research on their applications for assessing postacute sequelae of SARS-CoV-2 (PASC) or long COVID.To better understand digital biometric patterns in long COVID using wearable device technology and whether there are any differences between the nirmatrelvir-ritonavir and placebo-ritonavir intervention arms.This secondary analysis is an exploratory substudy of a placebo-controlled randomized clinical trial (Selective Trial of Paxlovid for PASC [STOP-PASC]) that was conducted from November 2022 to September 2023 at Stanford University. Trial participants were randomized, and a subset enrolled into the prespecified substudy.Participants were randomized 2:1 to receive oral nirmatrelvir (300 mg) and ritonavir (100 mg) or placebo-ritonavir twice daily for 15 days. Substudy participants were provided with a smartwatch and asked to wear it for 24 hours a day, 7 days a week for the 15-week study.Mean changes in digital biometric measures in physical activity, heart rate, and oxygen saturation tracked by a smartwatch. Biometric measures were summarized by treatment arm for each of 5 different time frames: baseline, treatment period, and 3 subsequent time intervals. Summary measure trajectories were clustered and demographics and clinical characteristics were compared among clusters using absolute standardized differences expressed in units of SDs.Of the 94 participants enrolled in the substudy, 50 (37 in nirmatrelvir-ritonavir and 13 in placebo-ritonavir) met the analysis eligibility criteria based on wear time and data completeness. These participants had a mean (SD) age of 42.7 (13.2) years and included 29 females (58.0%). Using mixed models for repeated measures, no significant differences were detected between the intervention arms in the change in biometric measures over time, consistent with the patient-reported outcomes in the STOP-PASC trial. In the overall substudy cohort, latent class mixed models and cluster analysis identified distinct longitudinal trajectories of long COVID over the 15-week study that tracked with different symptoms. Participants with lower daytime physical activity reported more severe fatigue (9 of 9 [100%] vs 21 of 23 [91.3%]; absolute standardized difference [ASD], 0.30), shortness of breath (9 of 9 [100%] vs 7 of 23 [30.4%]; ASD, 1.31), and cardiovascular symptoms (8 of 9 [88.9%] vs 12 of 23 [52.2%]; ASD, 0.70). Those with higher nighttime physical activity reported more gastrointestinal symptoms (2 of 3 [66.7%] vs 11 of 35 [31.4%]; ASD, 0.50). Additionally, participants with higher median daytime heart rates reported less fatigue (7 of 9 [77.8%] vs 39 of 40 [97.5%]; ASD, 0.63) and shortness of breath (3 of 9 [33.3%] vs 23 of 40 [57.5%]; ASD, 0.50) compared with those with lower heart rates.This secondary analysis identified distinct longitudinal trajectories of physiological and behavioral digital biometric measures captured from wearable devices that reflect the heterogeneity and track with different symptoms of long COVID. Digital biometric measures from wearable devices have promising utility for long COVID research.ClinicalTrials.gov Identifier: NCT05576662.

  View details for DOI 10.1001/jamanetworkopen.2025.26901

  View details for PubMedID 40810942

  View details for PubMedCentralID PMC12355292

• Post-COVID-19 Vaccination and Long COVID: Insights from Patient-Reported Data VACCINES Quach, T. C., Miglis, M. G., Tian, L., Bonilla, H., Yang, P. C., Grossman, L., Paleru, A., Xin, V., Tiwari, A., Shafer, R. W., Geng, L. N. 2024; 12 (12)

  View details for DOI 10.3390/vaccines12121427

  View details for Web of Science ID 001385630200001

• Evaluation of Postoperative Outcomes Following Early and Late Palate Repair: A Preclinical Study. The Journal of craniofacial surgery Aellos, F., Verma, I., Ly, M., Hoy, M., Quach, T., Rosbander, I., Sandoval, A., Wolvis, E., Turkkahraman, H., Helms, J. A. 2024

  Abstract

  To quantitatively assess the impact of early versus late surgical intervention on midfacial growth using a mouse model.A full-thickness mucoperiosteal flap surgery was performed on newborn (P17) mice and on neonatal (P30) mice. High-resolution micro-computed tomographic imaging coupled with histomorphometric analyses was used to assess craniomaxillofacial growth. Histology and immunohistochemical analyses were used to assess cellular and molecular responses postsurgery.Early surgical intervention at P17 resulted in significant midfacial growth arrest, with pronounced maxillary hypoplasia. Histomorphometric analyses revealed significant (P < 0.05) growth disruptions in the mid-palatal suture complex, including premature removal of the cartilaginous growth plate and its replacement by bone. In the suture itself, cell proliferation was significantly reduced (P < 0.05) compared with controls. The same surgical intervention performed in mice at P30 did not lead to significant midfacial growth arrest.Early surgical intervention in a mouse model mirrors the adverse growth outcomes in children undergoing early cleft repair. Molecular and cellular observations accompanying this midfacial growth arrest may inform therapeutic strategies to mitigate midfacial growth disturbances in patients and highlight the need for refined surgical techniques to minimize adverse growth outcomes.

  View details for DOI 10.1097/SCS.0000000000010827

  View details for PubMedID 39499137

• Nirmatrelvir-Ritonavir and Symptoms in Adults With Postacute Sequelae of SARS-CoV-2 Infection: The STOP-PASC Randomized Clinical Trial. JAMA internal medicine Geng, L. N., Bonilla, H., Hedlin, H., Jacobson, K. B., Tian, L., Jagannathan, P., Yang, P. C., Subramanian, A. K., Liang, J. W., Shen, S., Deng, Y., Shaw, B. J., Botzheim, B., Desai, M., Pathak, D., Jazayeri, Y., Thai, D., O'Donnell, A., Mohaptra, S., Leang, Z., Reynolds, G. Z., Brooks, E. F., Bhatt, A. S., Shafer, R. W., Miglis, M. G., Quach, T., Tiwari, A., Banerjee, A., Lopez, R. N., De Jesus, M., Charnas, L. R., Utz, P. J., Singh, U. 2024

  Abstract

  There is an urgent need to identify treatments for postacute sequelae of SARS-CoV-2 infection (PASC).To assess the efficacy of a 15-day course of nirmatrelvir-ritonavir in reducing the severity of select PASC symptoms.This was a 15-week blinded, placebo-controlled, randomized clinical trial conducted from November 2022 to September 2023 at Stanford University (California). The participants were adults with moderate to severe PASC symptoms of 3 months or longer duration.Participants were randomized 2:1 to treatment with oral nirmatrelvir-ritonavir (NMV/r, 300 mg and 100 mg) or with placebo-ritonavir (PBO/r) twice daily for 15 days.Primary outcome was a pooled severity of 6 PASC symptoms (fatigue, brain fog, shortness of breath, body aches, gastrointestinal symptoms, and cardiovascular symptoms) based on a Likert scale score at 10 weeks. Secondary outcomes included symptom severity at different time points, symptom burden and relief, patient global measures, Patient-Reported Outcomes Measurement Information System (PROMIS) measures, orthostatic vital signs, and sit-to-stand test change from baseline.Of the 155 participants (median [IQR] age, 43 [34-54] years; 92 [59%] females), 102 were randomized to the NMV/r group and 53 to the PBO/r group. Nearly all participants (n = 153) had received the primary series for COVID-19 vaccination. Mean (SD) time between index SARS-CoV-2 infection and randomization was 17.5 (9.1) months. There was no statistically significant difference in the model-derived severity outcome pooled across the 6 core symptoms at 10 weeks between the NMV/r and PBO/r groups. No statistically significant between-group differences were found at 10 weeks in the Patient Global Impression of Severity or Patient Global Impression of Change scores, summative symptom scores, and change from baseline to 10 weeks in PROMIS fatigue, dyspnea, cognitive function, and physical function measures. Adverse event rates were similar in NMV/r and PBO/r groups and mostly of low grade.The results of this randomized clinical trial showed that a 15-day course of NMV/r in a population of patients with PASC was generally safe but did not demonstrate a significant benefit for improving select PASC symptoms in a mostly vaccinated cohort with protracted symptom duration. Further studies are needed to determine the role of antivirals in the treatment of PASC.ClinicalTrials.gov Identifier: NCT05576662.

  View details for DOI 10.1001/jamainternmed.2024.2007

  View details for PubMedID 38848477

• Myalgic Encephalomyelitis/Chronic Fatigue Syndrome is common in post-acute sequelae of SARS-CoV-2 infection (PASC): Results from a post-COVID-19 multidisciplinary clinic. Frontiers in neurology Bonilla, H., Quach, T. C., Tiwari, A., Bonilla, A. E., Miglis, M., Yang, P. C., Eggert, L. E., Sharifi, H., Horomanski, A., Subramanian, A., Smirnoff, L., Simpson, N., Halawi, H., Sum-Ping, O., Kalinowski, A., Patel, Z. M., Shafer, R. W., Geng, L. C. 2023; 14: 1090747

  Abstract

  The global prevalence of PASC is estimated to be present in 0·43 and based on the WHO estimation of 470 million worldwide COVID-19 infections, corresponds to around 200 million people experiencing long COVID symptoms. Despite this, its clinical features are not well-defined.We collected retrospective data from 140 patients with PASC in a post-COVID-19 clinic on demographics, risk factors, illness severity (graded as one-mild to five-severe), functional status, and 29 symptoms and principal component symptoms cluster analysis. The Institute of Medicine (IOM) 2015 criteria were used to determine the Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) phenotype.The median age was 47 years, 59.0% were female; 49.3% White, 17.2% Hispanic, 14.9% Asian, and 6.7% Black. Only 12.7% required hospitalization. Seventy-two (53.5%) patients had no known comorbid conditions. Forty-five (33.9%) were significantly debilitated. The median duration of symptoms was 285.5 days, and the number of symptoms was 12. The most common symptoms were fatigue (86.5%), post-exertional malaise (82.8%), brain fog (81.2%), unrefreshing sleep (76.7%), and lethargy (74.6%). Forty-three percent fit the criteria for ME/CFS, majority were female, and obesity (BMI > 30 Kg/m2) (P = 0.00377895) and worse functional status (P = 0.0110474) were significantly associated with ME/CFS.Most PASC patients evaluated at our clinic had no comorbid condition and were not hospitalized for acute COVID-19. One-third of patients experienced a severe decline in their functional status. About 43% had the ME/CFS subtype.

  View details for DOI 10.3389/fneur.2023.1090747

  View details for PubMedID 36908615

  View details for PubMedCentralID PMC9998690

• Can Low Cortisol Predict Long COVID? A Controversial Issue Biomedicines Quach, T. C., Wilson, A., Sum-Ping, O., Lomba, S., Geng, L. N., Shafer, R., Miglis, M. G., Yang, P. C., Grossman, L., Ricciardiello, G., Bonilla, H. 2025; 13 (11): 2636

  View details for DOI 10.3390/biomedicines13112636

• Risk of developing long COVID based on acute COVID-19 severity JOURNAL OF PUBLIC HEALTH-HEIDELBERG Van Cleve, R., Quach, T., Shaheen, M., Bell, K., Roshwalb, A., Petrin, R., Geng, L. N., Asch, S. M., Lienau, A. 2024

  View details for DOI 10.1007/s10389-024-02364-2

  View details for Web of Science ID 001351139800001

• Social determinants of health associated with developing long COVID in the US veteran population JOURNAL OF PUBLIC HEALTH-HEIDELBERG Van Cleve, R., Quach, T., Shaheen, M., Bell, K., Roshwalb, A., Petrin, R., Geng, L. N., Asch, S. M., Lienau, A. 2024

  View details for DOI 10.1007/s10389-024-02284-1

  View details for Web of Science ID 001238134000001

• New Alcohol Sensitivity in Patients With Post-acute Sequelae of SARS-CoV-2 (PASC): A Case Series. Cureus Eastin, E. F., Tiwari, A., Quach, T. C., Bonilla, H. F., Miglis, M. G., Yang, P. C., Geng, L. N. 2023; 15 (12): e51286

  Abstract

  Post-acute sequelae of SARS-CoV-2 (PASC), or long COVID, is characterized by persistent symptoms after acute SARS-CoV-2 infection that can vary from patient to patient. Here, we present a case series of four patients with a history of SARS-CoV-2 infection referred to the Post-Acute COVID-19 Syndrome (PACS) Clinic at Stanford University for evaluation of persistent symptoms, who also experienced new-onset alcohol sensitivity. Alcohol reactions and sensitivity are not well characterized in the literature as it relates to post-viral illness. While there have been some anecdotal reports of new alcohol sensitivity in PASC patients in the media, there is a paucity of published data in the medical literature about this topic. During their medical consultation, the patients self-reported new changes in their symptoms or behaviors following the use of alcohol. A new onset of alcohol sensitivities should be assessed along with other post-COVID-19 symptoms and may provide novel avenues to explore the pathobiology of illness and potential interventions.

  View details for DOI 10.7759/cureus.51286

  View details for PubMedID 38288178

  View details for PubMedCentralID PMC10823305