JMIR Publications

ABSTRACT

Background:

Leprosy is a chronic, granulomatous and infectious disease caused by Mycobacterium leprae and M. lepromatosis. The clinical characterization of the disease can vary widely, from paucibacillary forms (with few bacilli) to multibacillary forms (with a higher bacillary load). The diagnosis of leprosy is primarily clinical, based on the observation of the characteristic signs and symptoms of the disease, such as skin lesions with changes in sensitivity, neural impairment and lesions in the peripheral nerves. In addition to the clinical evaluation, laboratory tests such as bacilloscopy (for detection of acid-fast bacilli in smears of lesions) and skin biopsy can also be used to aid in diagnosis. It is important to mention that there is no standard complementary test with 100% sensitivity. Therefore, the diagnosis is often made based on a combination of clinical, laboratory and molecular criteria. Non-invasive tests have been developed to assess peripheral nerves, such as nerve ultrasound, which have shown promise in aiding early diagnosis and monitoring of leprosy neuropathy. Although neural histopathological examination is highly accurate, it is rarely used due to the possibility of neural sequelae. Ultrasound examination allows the collection of perineural biological material in a minimally invasive manner, without damaging nerve structures. The investigation of genetic material of the etiological agents that cause leprosy through perineural collection, guided by ultrasound, is a promising method for improving diagnostic accuracy in leprosy.

Objective:

Perform clinical, molecular and ultrasonographic follow-up of suspected leprosy patients with the objective of evaluating the accuracy of ultrasonographic and molecular markers (DNA and RNA) in the diagnosis and follow-up of leprosy. The study will be carried out at the University Hospital of Brasília (UHB), a reference center for the treatment of leprosy in the central-west region of Brazil.

Methods:

Diagnostic study with consecutive prospective collection of patients referred to the leprosy outpatient clinic of the University Hospital of Brasília for diagnosis and treatment of the disease. During follow-up, clinical and molecular examinations will be performed, and their results will be compared to the sonographic findings, which will be collected monthly for one year. Patients will be evaluated clinically, by ultrasound and molecularly in 2 stages of leprosy diagnosis and treatment. The steps consist of a time immediately after clinical diagnosis and 1 year after the start of treatment. Perineural fine needle aspiration of the ulnar nerve will be performed in the ulnar tunnel, guided by ultrasound using a 26 gauge needle. The aspirated material will be used for identification of bacillary DNA and RNA at the time of diagnosis and 1 year after the start of treatment.

Results:

Patient recruitment started in January 2026 and is expected to be concluded in Dezember 2026. Analysis of collected data will be between February and July 2027, being results expected to be published by august 2027.

Conclusions:

It is believed that ultrasound-guided perineural aspirate will increase the accuracy of leprosy diagnosis and may demonstrate the viability of the bacillus before and after treatment by RNA identification. Clinical Trial: Https://plataformabrasil.saude.gov.br/