VZV in the Enteric Nervous System: Pathogenesis and Consequences

May 22, 2026 updated by: Michael Vaezi, Vanderbilt University Medical Center
Varicella zoster virus (VZV) is the cause of chickenpox and shingles, but it also infects, becomes latent, and reactivates in nerve cells of the bowel to cause a gastrointestinal disorder ("enteric shingles"). The Investigators recently found that a chronic active VZV infection, a form of enteric shingles, is associated with achalasia, a severe disease in which the passage of food from esophagus to stomach is impaired. We now propose to eradicate VZV to determine whether its association with achalasia is causal, to identify the genetic basis behind VZV reactivation in the esophagus, and the relationship of mast cells to enteric shingles and abdominal pain.

Study Overview

Status

Recruiting

Conditions

Detailed Description

Varicella zoster virus (VZV) is so well known as the cause of cutaneous varicella (chickenpox) and zoster (shingles) that it can be hard to imagine it as an enteric pathogen. VZV establishes latency during varicella and returns to the skin in zoster when the neurons in which VZV reactivates have cutaneous projections. Because a viremia occurs during varicella, VZV also infects and establishes latency in enteric neurons that do not innervate the skin. VZV can reactivate in enteric neurons to give rise to "enteric zoster", which can occur without an associated rash. Because a rash may thus be absent, pain due to enteric zoster can be occult. The Investigators have found, however, that VZV DNA, which is absent from normal saliva, is detectable in saliva whenever an active (lytic) VZV infection is present in the body; thus, detection of salivary VZV is a non- invasive diagnostic tool that, in combination with enteric signs and symptoms, helps to identify GI disorders that involve VZV. The Investigators have found VZV transcripts and protein in endoscopic biopsies from patients with occult abdominal pain and salivary VZV DNA, which verifies that these patients have enteric zoster. These observations led the Investigators to investigate the potential association between VZV and achalasia in 15 patients.

The Investigators found salivary VZV DNA in 12/15 subjects examined prior to myotomy and, subsequently, VZV transcripts in 13/15 of the resected myotomy specimens. The tissue also contained VZV immunoreactive (gE, gH, ORF40p) neurons, nerve fibers, and multinucleated giant cells. To help determine whether this persistent VZV infection of esophageal neurons is causally related to achalasia, the Investigators now propose to conduct a clinical trial of valacyclovir to determine whether eradication of VZV alleviates achalasia symptoms and improves esophageal function. The Investigators also plan to quantify viral load in relation to achalasia phenotypes and employ next generation sequencing to look for a genetic basis of esophageal VZV reactivation. Finally, because mast cell accumulation and degranulation have been reported in the achalasia esophagus and verified in our preliminary data, the Investigators will test the hypothesis that mast cell activation contributes to manifestations and/or painful symptoms of VZV- associated achalasia. To gain insight into mechanisms of achalasia pathogenesis, the Investigators will also determine whether VZV reactivates specifically in neurons thought to control relaxation of the lower esophageal sphincter (nitric oxide synthase) and/or the excitatory phase of esophageal peristalsis (choline acetyltransferase). Viral destruction of nitrergic inhibitory neurons could be a cause of failure of LES smooth muscle to relax and either or both of these neurons could contribute to the loss of peristalsis that accompanies achalasia.

Study Type

Interventional

Enrollment (Estimated)

40

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 75 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Male and female subjects aged 18-75 years old inclusive (females of childbearing potential should be on highly effective contraceptive methods)
  • Fluent in English and mentally capable to provide informed consent who present to Vanderbilt University Medical Center Digestive Diseases Center for treatment of achalasia.
  • Based on standard clinical practice, we anticipate that patients who undergo these treatments will have been formally diagnosed with achalasia and will be fit to undergo the selected treatment intervention.
  • All subjects must be able to undergo timed barium swallow testing, trans-nasal intubation for high-resolution manometry probe, and therapeutic intervention of a 2-month course of valacyclovir 1g TID and two injections of Shingrix over a two-month period.

Exclusion Criteria:

  • Unstable medical illness with ongoing diagnostic work-up and treatment. Patients with well-controlled hypertension, diabetes and a remote history of ischemic heart disease that is deemed stable, as judged by the physician-investigator can be included.
  • Current neurologic or cognitive impairment which would make the patient an unsuitable candidate for a research trial.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Treatment
Patients with Achalasia (phenotypes II and III) with VZV DNA in saliva. Patients will be treated with valacyclovir 3 times per day. Patients found to benefit from treatment with valacyclovir will be offered Shingrix vaccine (2 - 0.5mL doses)
Valacyclcovir is a targeted anti-viral for varicella zoster virus (VZV).
Other Names:
  • Valtrex
Vaccine indicated for prevention of herpes zoster
Other Names:
  • Zoster vaccine recombinant

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Response of VZV-associated achalasia to anti-VZV therapy.
Time Frame: 4 months
Response will be measured by the Eckardt score. The Eckardt score is the sum of the symptom scores for dysphagia, regurgitation, and chest pain (with a score of 0 indicating the absence of symptoms, 1 indicating occasional symptoms, 2 indicating daily symptoms, and 3 indicating symptoms at each meal) and weight loss (with 0 indicating no weight loss, 1 indicating a loss of <5 kg, 2 indicating a loss of 5 to 10 kg, and 3 indicating a loss of >10 kg).
4 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Difference in viral loads in achalasia phenotype II versus phenotype III
Time Frame: One year
Difference in viral load will be measured by real-time qPCR to quantify VZV transcripts (ORF40, ORF67) to estimate the severity of VZV infection.
One year
Genetic typing of reactivation of VZV in the esophagus
Time Frame: One year
Next-generation sequencing will generate whole VZV genomes from the low amounts of DNA found in clinical samples for VZV genotyping
One year
Incidence of reactivation of VZV due to mast cell degranulation
Time Frame: One year
Number of subjects found to have mast cell disorder
One year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Collaborators

Investigators

  • Principal Investigator: Michael Vaezi, MD, Vanderbilt University Medical Center

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 27, 2023

Primary Completion (Estimated)

August 1, 2026

Study Completion (Estimated)

August 1, 2026

Study Registration Dates

First Submitted

September 19, 2022

First Submitted That Met QC Criteria

September 19, 2022

First Posted (Actual)

September 22, 2022

Study Record Updates

Last Update Posted (Actual)

May 27, 2026

Last Update Submitted That Met QC Criteria

May 22, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Yes The investigators agree to the timely release and sharing of information to be no later than the acceptance for publication of the main findings from the final data set. Investigators are also committed to ensuring that all data are free of identifiers that would permit linkage to individual research participation as well as variables that could lead to deductive disclosure of individual subjects.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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