Clinical Research Directory

Accuracy of the Polymerase Chain Reaction of Ulnar Perineural Subcutaneous Aspirate Guided by Ultrasound for the Diagnosis and Monitoring of Leprosy Cure

\*\*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.

Epidemiological, Clinical, Diagnostic, and Therapeutic Characteristics of Hansen's Disease in Costa Rica (2018-2025)

The goal of this observational retrospective study is to characterize the epidemiologic, clinical, diagnostic, and therapeutic features of Hansen's disease cases in Costa Rica between 2018 and 2025. The main questions it aims to answer are: What are the epidemiologic and clinical characteristics of confirmed Hansen's disease cases in Costa Rica? What diagnostic methods, treatments, complications, and outcomes are observed in routine care? All confirmed Hansen's disease cases recorded in national surveillance and with available clinical records during 2018-2025 will be included. Data will be obtained from electronic health records and Ministry of Health reports without participant contact.

Efficacy and Tolerability of Adjunct Metformin for Multibacillary Leprosy

This trial aims to evaluate the efficacy, tolerability and safety of adjunct metformin added to standard-of-care multi-drug therapy (MDT) in patients with multibacillary leprosy, and explore its effects on immunological endpoints. A double-blind, placebo controlled proof-of-concept trial will be performed in which patients with newly diagnosed multibacillary leprosy will be randomized (1:1) to metformin 1000mg OD versus placebo for 24 weeks in addition to MDT during 48 weeks. The main research question is whether adjunctive metformin, combined with MDT, will improve the clinical outcomes of patients with multibacillary leprosy by mitigating leprosy reactions, thereby reducing nerve damage and corticosteroid use and its associated morbidity. The second aim is to explore whether adjunct metformin, added to MDT, has an acceptable tolerability and safety in patients with multibacillary leprosy.