Spontaneous Antigenemia in Loiasis

• Conditions: Lymphatic Filariasis; Loiasis
• Interventions: Other: No intervention

• Registration Number: NCT04258670
• Lead Sponsor: Washington University School of Medicine

Brief Summary

This prospective study will enroll and follow 60 loiasis patients with high worm burden to monitor the spontaneous release of filarial antigen in peripheral blood. This study will define the cross-reactive antigen profile of persons with spontaneous loiasis antigenemia, and determine whether it varies with time.

Detailed Description

Global efforts to eradicate lymphatic filariasis (LF) depend on rapid diagnostic tests (RDTs) that detect Wuchereria bancrofti circulating filarial antigen but these tests are unreliable in African nations where Loa loa is co-endemic because they yield false-positive results in some individuals with loiasis. The goals of this project are to define the cross-reactive antigen profile of persons with spontaneous antigenemia, how it varies over time, and to determine which L. loa antigens in cross-reactive sera best distinguish loiasis cross-reactivity from LF.

This prospective study will prospectively enroll 50 adults who presented with cross-reactive antigenemia at screening and 10 negative controls. Participants will followed for one year and tested every three months for persistence of antigenemia.

Basic Information
|
Recruitment & Eligibility
|
Study & Design
|
Trial Locations

Study Timeline

• Study Start: 2020-01-23
• Study First Submitted: 2020-02-03
• Study First Submitted QC: 2020-02-03
• Study First Posted: 2020-02-06
• Status Verified: 2020-07
• Last Update Submitted: 2020-07-27
• Last Update Posted: 2020-07-29
• Primary Completion: 2021-05
• Study Completion: 2021-12-31

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 60

Inclusion Criteria

• Ability to give informed consent
• Loiasis Mf count > 20,000 Mf/mL
• Resident of study area
• No evidence of severe or systemic comorbidities
• Consent to storage of blood samples for future study

Read More

Exclusion Criteria

• Subject plans to move from the study area during subsequent 12 months

Read More

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Cross-reactive loiasis	No intervention	This cohort will prospectively enroll 50 adults (age 18+) with cross-reactive antigenemia based on a positive filariasis test strip (FTS) and L. loa Mf counts \>20,000 Mf/mL.

Primary Outcome Measures

Name	Time	Method
prevalence of specific cross-reactive L. loa antigens at baseline	1 day	Prevalence of filariasis test strip (FTS) positive individuals at screening. Cross-reactive proteins in plasma will be identified by mass-spectrometry to identify a cross-reactive biomarker

Secondary Outcome Measures

Name	Time	Method
Recurrence of cross-reactive antigenemia	quarterly for 1 year	To determine if the same antigens are present at each follow up

Trial Locations

Locations (1)

Centre for Research on Filariasis and other Tropical Diseases (CRFilMT); 🇨🇲 Yaoundé, Cameroon