Accuracy of the Polymerase Chain Reaction of Ulnar Perineural Subcutaneous Aspirate Guided by Ultrasound for the Diagnosis and Monitoring of Leprosy Cure (Does not exist)

April 2, 2026 updated by: Daniel Holanda Barroso, University of Brasilia

**Brief Summary**

Leprosy is a chronic granulomatous infectious disease caused by *Mycobacterium leprae* or *Mycobacterium lepromatosis*, characterized by peripheral nerve involvement that may lead to progressive neurological damage, disability, and deformities if not diagnosed and treated early. The diagnosis of leprosy is primarily clinical and epidemiological, supported by laboratory methods such as bacilloscopy and biopsy; however, these tests have limited sensitivity, particularly due to the bacillus' tropism for peripheral nerve structures.

Ultrasonography has emerged as a non-invasive imaging method capable of detecting morphological changes in peripheral nerves, including nerve enlargement, fascicular abnormalities, and inflammatory hypervascularization. Despite its diagnostic value, ultrasonography alone cannot detect the presence of the bacillus.

This prospective cohort study aims to evaluate the diagnostic and prognostic accuracy of combining clinical evaluation, peripheral nerve ultrasonography, and molecular detection techniques using subcutaneous perineural aspirate. Patients with suspected leprosy attending the Leprosy Outpatient Clinic at the University Hospital of Brasília will undergo clinical evaluation, ultrasound examination of the ulnar nerves, and ultrasound-guided subcutaneous perineural aspirate for molecular detection of *Mycobacterium leprae* DNA and RNA using real-time PCR and RT-PCR.

Participants will be followed for one year, with assessments performed at diagnosis and after one year of treatment. The study will compare clinical, imaging, and molecular findings to determine whether perineural subcutaneous aspirate combined with ultrasonography improves early detection and diagnostic accuracy compared with conventional methods such as bacilloscopy and biopsy.

The study aims to contribute to improved diagnostic strategies for leprosy, enabling earlier detection of neural involvement and potentially reducing disease transmission and long-term disability.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Leprosy is a chronic infectious disease caused by Mycobacterium leprae and is characterized by skin and peripheral nerve involvement. Neural impairment is the main determinant of disability and long-term morbidity. Early diagnosis remains challenging because current diagnostic methods have important limitations. Slit-skin smear microscopy and skin biopsy have low sensitivity in many clinical settings, especially in paucibacillary and primary neural forms. Nerve palpation is widely used but lacks reproducibility and does not distinguish among etiologies of neuropathy. Nerve biopsy, although more precise in selected cases, is invasive and may cause permanent neurological sequelae.

High-resolution ultrasonography has emerged as a promising tool for evaluation of leprosy neuropathy because it allows objective assessment of peripheral nerve cross-sectional area, asymmetry, fascicular abnormalities, and intraneural or epineural hypervascularity using Doppler. However, ultrasound cannot directly detect the bacillus.

Molecular methods have expanded the diagnostic possibilities in leprosy. Real-time PCR targeting the repetitive element RLEP can detect M. leprae DNA with high sensitivity. However, DNA detection alone does not distinguish viable from non-viable bacilli. Detection of RNA by RT-PCR, including targets such as 16S rRNA and sodA, may provide evidence of bacillary viability because RNA degrades rapidly after cell death. This approach may improve treatment monitoring and refine the concept of cure.

The present study proposes a minimally invasive strategy based on ultrasound-guided ulnar perineural subcutaneous aspirate. Biological material will be collected adjacent to the affected nerve, avoiding direct nerve biopsy and potentially increasing the sensitivity of molecular detection in the neural microenvironment. Participants with suspected leprosy will be assessed clinically, by high-resolution ultrasound of the ulnar nerves, and by molecular detection of M. leprae DNA and RNA in aspirated material. They will be evaluated at baseline, near the time of diagnosis, and after one year of treatment.

The main objective is to determine the diagnostic accuracy of ultrasound-guided perineural aspirate PCR/RT-PCR compared with conventional methods. Secondary objectives include correlation of ultrasound abnormalities with molecular positivity, assessment of bacillary viability over time, and development of workflows potentially applicable to the public health system, including referral centers and settings using portable ultrasound.

Study Type

Interventional

Enrollment (Estimated)

108

Phase

  • Not Applicable

Contacts and Locations

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

Study Locations

  • Brazil
    • Federal District
      • Brasília, Federal District, Brazil, 70.830-200

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

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

Individuals aged 14 years or older;

Clinical suspicion of leprosy based on dermatologic or neurologic examination OR;

Presence of peripheral nerve enlargement or skin lesions compatible with leprosy;

Ability to provide written informed consent.

-

Exclusion Criteria:

Previous treatment for leprosy;

Contraindication to the aspiration procedure (e.g., coagulopathy or anticoagulant therapy);

Local infection at the puncture site;

Inability or unwillingness to provide informed consent.

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Suspected Leprosy Cohort
Participants with suspected leprosy undergoing clinical evaluation, peripheral nerve ultrasound, ultrasound-guided ulnar perineural subcutaneous aspirate, and molecular testing for detection of Mycobacterium leprae DNA and RNA.
Diagnostic test: Ultrasound-Guided Ulnar Perineural Subcutaneous Aspirate
Ultrasound-guided subcutaneous aspirate performed adjacent to the ulnar nerve using a 26G needle and sterile saline, followed by molecular analysis for detection of Mycobacterium leprae DNA and RNA by real-time PCR and RT-PCR.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Diagnostic accuracy of perineural aspirate PCR for detection of Mycobacterium leprae
Time Frame: Baseline diagnostic evaluation
Sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of PCR performed on ultrasound-guided perineural aspirate will be calculated using the WHO leprosy composite reference standard as the gold standard. Results will be expressed as proportions with 95% confidence intervals. The overall accuracy will be the main outcome
Baseline diagnostic evaluation

Collaborators and Investigators

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

Sponsor

University of Brasilia

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)

January 1, 2026

Primary Completion (Estimated)

December 31, 2026

Study Completion (Estimated)

August 31, 2027

Study Registration Dates

First Submitted

March 12, 2026

First Submitted That Met QC Criteria

April 2, 2026

First Posted (Actual)

April 7, 2026

Study Record Updates

Last Update Posted (Actual)

April 7, 2026

Last Update Submitted That Met QC Criteria

April 2, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 85116624.2.0000.5558

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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.

Clinical Trials on Mononeuropathies

Clinical Trials on Ultrasound-Guided Ulnar Perineural Subcutaneous Aspirate

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Bangladesh

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe