Tuberculosis | Effect of Filarial Infection on Immune Responses in Latent Tuberculosis

Tuberculosis research study

What is the primary objective of this study?

Background: - Lymphatic filariasis is an infection that is caused by small, thread-like worms. It is spread by mosquitoes, and causes fever, chills, and headaches. If untreated, it can also cause elephantiasis, a condition that leads to swelling of the arms, legs, breasts, and scrotum. Treatment can eliminate the worms from the blood and reduce the risk of developing elephantiasis. Researchers want to study people with latent tuberculosis (TB) who may or may not be infected with filariasis. This study will look at the way that people with latent TB fight infection with these worms. Objectives: - To study how the immune systems of people with latent TB react to filarial infection. Eligibility: - Individuals between 18 and 65 years of age who have latent TB and may or may not have filarial infection. Design: - Participants will be screened with a physical exam and medical history. They will provide a blood and stool sample to test for infection. - Participants who do not have lymphatic filariasis but have another kind of intestinal worm will be treated for the parasite. This will be their last study visit. - Participants who have latent TB and lymphatic filariasis will be treated with the standard treatment for the disease. They will come back for a second visit 6 months later, and will provide another blood sample.

Who is eligible to participate?

- PARTICIPANT INCLUSION CRITERIA: Individuals (18 to 65 years of age) who meet the following criteria are eligible to participate in the study: - Positive tuberculin PPD skin test result (>or equal to 5 mm) and IGRA+. - Willingness to provide blood and stool samples for examination. - Willingness to have samples stored for study participants only. PARTICIPANT EXCLUSION CRITERIA: Individuals are not eligible to participate if: - Pulmonary symptoms suggestive of TB (cough >3 weeks in duration and/or intermittent fever >1 week in duration and/or hemoptysis). - Tuberculin skin test within the last 6 months prior to screening. - Women who are pregnant or breastfeeding. - Known documented cases of cancer, acquired immune deficiency syndrome, or other immunosuppressive illness. - History of any other illness or condition which, in the investigator s judgment, may substantially increase the risk associated with the subject s participation in the protocol, or it may compromise the scientific objectives. - Consumption of DEC in the last one year prior to screening. - EXCLUSION OF PREGNANT WOMEN: - Pregnancy: Pregnant and lactating women will be excluded from the study because the safety of DEC or ivermectin has not been adequately evaluated during pregnancy or lactation, while albendazole is a Category C drug found to be teratogenic in animals, and it poses a potential risk during breastfeeding. - EXCLUSION OF CHILDREN: Children (<18 years of age) will not be included in this study due to the fact the prevalence of filarial and strongyloides infection in children has been found to be very low in South India.

Which medical condition, disease, disorder, syndrome, illness, or injury is researched?



Study Interventions

Interventions can include giving participants drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available or noninvasive approaches such as surveys, education, and interviews.

Study Arms

Research studies and clinical trials typically have two or more research arms. An arm is a group of people who receive the same treatment in the study.

Study Status


Start Date: February 7, 2012

Completed Date:


Type: Observational


Primary Outcome: To compare the immune responses to mycobacterial antigens, including PPD and Mycobacterium tuberculosis culture filtrate protein, in individuals who are LTBI+ Fil- versus those who are LTBI+ Fil+.

Secondary Outcome: To compare immune responses to mycobacterial antigens in LTBI+Fil+ co-infected individuals, before and after treatment for filarialinfection.

Study sponsors, principal investigator, and references

Principal Investigator: Thomas B Nutman, M.D.

Lead Sponsor: National Institute of Allergy and Infectious Diseases (NIAID)


More information:

Kumar NP, George PJ, Kumaran P, Dolla CK, Nutman TB, Babu S. Diminished systemic and antigen-specific type 1, type 17, and other proinflammatory cytokines in diabetic and prediabetic individuals with latent Mycobacterium tuberculosis infection. J Infect Dis. 2014 Nov 15;210(10):1670-8. doi: 10.1093/infdis/jiu329. Epub 2014 Jun 6.

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