An observational study in Mycobacterium Infections, Tuberculosis and Filariasis, sponsored by National Institute of Allergy and Infectious Diseases (NIAID). Completed at 2 sites in 2 countries. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2021-04-20.
Sponsored by National Institute of Allergy and Infectious Diseases (NIAID) · Observational
Background:
Objectives:
Eligibility:
Design:
Tissue-invasive helminth parasites infect close to 500 million people worldwide and are associated with strong T helper (Th)2 responses and regulatory networks that downregulate potentially protective Th1 responses. The two common tissue invasive helminth parasites are Wuchereria bancrofti, that causes lymphatic filariasis and Strongyloides stercoralis, that causes stronyloidiasis. Previous studies have shown that the intestinal helminth coinfection is accompanied by lowered in vitro production of interferon-gamma and elevated production of interleukin 10 in individuals with active pulmonary tuberculosis (TB). Our team has recently shown that co-existent filarial TB infections down-regulate Th1 and Th17 responses, which are necessary for protection against active TB.
The current study will compare immune responses to mycobacterial antigens in individuals with latent tuberculosis (LTBI+) and concomitant helminth infection (Hel+), including those with filarial (Fil+) and strongyloides (STR+) infection versus those with LTBI+ without concomitant helminth infection (Hel-). Immune responses to mycobacterial antigens from co-infected individuals will also be evaluated before and after treatment for helminth infection. Individuals (n=4000) will sign a screening consent prior to undergoing any study procedures. Every participant will have their medical history collected and will undergo a physical exam and a tuberculin 2TU purified protein derivative (PPD) skin test; women of childbearing potential will also undergo a urine pregnancy test, and those with positive test results will be excluded from the study. Individuals with positive PPD skin test results (> or = 5 mm) and no symptoms of active TB will have their blood drawn (5 mL) as part of the screening procedures to confirm LTBI+ status, evaluate circulating filarial antigenemia, determine Strongyloides status by ELISA, measure hematocrit levels, and for storage of serum samples; those with PPD skin test results less than or equal to 5 mm will be excluded from the study. Individuals with positive symptoms for TB will also be excluded from the study, but sputum will be collected from them, and those with positive smears will be referred for treatment. Individuals will be matched for age, gender, and geographic location, and they will be assigned to one of two groups, LTBI+ Hel+ (n=100) or LTBI+ Hel- (n=100).
Within 3 months of screening, individuals will be asked to sign an on-study consent and will undergo a second blood draw (10 mL) for immunological investigations and storage of serum samples; women of childbearing potential will undergo a repeat urine pregnancy test, and those with positive test results will be excluded from further study. Stool samples will also be collected for microscopic evaluation of ova and parasites. LTBI+ Fil+ individuals will be treated with a single standard dose of albendazole (400 mg) and single standard dose of diethylcarbamazine citrate (300 mg), which are available through the National Programme for the Elimination of Lymphatic Filariasis in India. LTBI+ STR+ individuals will be treated with a single standard dose of ivermectin (12mg) and a single standard dose of albendazole (400mg). These individuals will be asked to return 6 months after treatment to undergo a third blood draw (10 mL) for additional immunological investigations and storage of serum samples. LTBI+ Hel-individuals who test positive for other intestinal helminth infection will be treated with a single standard dose of albendazole (400 mg).
199 studies on the registry are indexed under Latent Tuberculosis; 48 are open to participants now.
This study's enrollment of 4,268 is above the median of 260 across 82 observational studies indexed under Latent Tuberculosis.
Browse Latent Tuberculosis studies →National Institute of Allergy and Infectious Diseases (NIAID) is the lead sponsor of 2,446 studies on the registry; 179 are open to participants now.
Of its 405 completed or terminated interventional studies of FDA-regulated products, 302 (75%) have results posted.
Compared within Latent Tuberculosis, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Mycobacterium Infections. The counts are of registry records indexed under each term, refreshed daily. How we classify →
The screening will be a community-based study in South India. Study participants will be recruited from villages in the Kancheepuram District, where approximately 6% of the population tests positive for circulating filarial antigens [31]. PPD skin test reactivity in this population is virtually 100% to PPD-B (battery) and 60% to 70% to PPD-S (standard) by age 24, and the incidence of active TB is about 4 per 1000 individuals [31]. While the rate of positivity of the tuberculin skin test to the 2TU PPD test is not known, significant deviation in the percent positivity from skin tests using 1TU is not expected based on findings reported elsewhere [32]. However, we are revising the @@@screening sample number on the basis of preliminary data from the current study that shows that the prevalence of latent TB in this population is around 25% and filariasis is around 1%. In addition, preliminary data from these areas show that the prevalence of Stronglyloides infection is around 10%.
Individuals (18 to 65 years of age) who meet the following criteria are eligible to participate in the study:
PARTICIPANT EXCLUSION CRITERIA:
Individuals are not eligible to participate if:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Latent TB positive with helminth positive
Latent TB positive with helminth negative
To compare the immune responses to mycobacterial antigens, including PPD and Mycobacterium tuberculosis culture filtrate protein, in individuals who are LTBI+ Hel- versus those who are LTBI+Hel+
pending
Time frame: 5 years
To compare immune responses to mycobacterial antigens in LTBI+ Hel+ co- infected individuals, before and after treatment for filarialinfection.
Time frame: 5 years
This study is completed, as verified in Apr 2021. You cannot join it, but the record below documents what was studied.
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