DIAGNOSTICS

The first step to treating or curing a disease is quickly and accurately diagnosing it. The development of diagnostics for some of the world’s most neglected, but burdensome infectious diseases is an important part of IDRI’s research activities. The common goal of our diagnostics programs is to enable ready access to low-cost diagnostic products that are easy to use and stable for long periods despite the extreme environmental conditions characteristic of endemic regions. The diagnostic products should also provide a rapid readout suitable for use at the point of care or in a regional clinic.

products-diagnosticsOur current focus is the development of tests for antibody detection. Antibodies are proteins produced by the body’s immune system against specific foreign molecules of invading bacteria and viruses. The function of these antibodies is to neutralize pathogenic organisms; for this to happen successfully, they must bind very specifically with the pathogen molecules. The presence of specific antibodies within a person indicates that he or she has been infected by one of these pathogens.

Detecting these pathogen-specific antibodies as early as possible is critical for determining the most appropriate treatment regimen. Along with our manufacturing partners, we have shown — through extensive testing — that antibody-detection tests can be produced that are: highly specific to targeted antibodies, highly sensitive in order to identify infection early and low cost.

As a nonprofit organization, we are able to supply our commercial partners with the inexpensive, high-quality, unique molecules that are critically important to the manufacture and marketing of low-cost and accurate diagnostic tests. Currently, our reagents are available for license against visceral leishmaniasis, leprosy and Chagas disease. Diagnostic products using these reagents are already being used in several countries.

LEISHMANIASIS DIAGNOSTICS

CHALLENGE

Diagnosis of visceral leishmaniasis (VL) is complicated by the fact that its clinical features are shared by a host of other commonly occurring diseases, such as typhoid, malaria and tuberculosis. Previously, definitive diagnosis of VL has been accomplished by microscopic confirmation of the amastigote form of the parasite in tissue aspirates from spleen, bone marrow or lymph nodes. These methods are risky, inefficient, painful and expensive, requiring technical expertise, hospitalization and use of laboratory facilities, which are often not available in low-resource settings.

Early and accurate laboratory diagnosis is essential before initiating treatment for the following reasons:

  • The disease is usually always fatal if not treated in a timely manner.
  • The effective drugs are potentially toxic and expensive, often requiring long periods of hospitalization for administration.
  • Untreated cases of VL are active reservoirs of infection, thereby putting the community at risk of ongoing transmission.
SOLUTIONS

IDRI’s scientists were the first to identify rK39, a recombinant antigen that can be used to diagnose more than 98% of human visceral leishmaniasis cases with only a drop of blood. We have developed technologies for a diagnostic that is simple and easy to use in the field, requiring a single drop of blood to quickly diagnose leishmaniasis, rather than the previous method of diagnosis which was invasive and painful. This diagnostic is currently being used around the world, in more than 20 countries, including India and Bangladesh which have high VL disease burdens.

Now we are working on next steps, including:

  • Develop and evaluate a cost-effective and affordable point-of-care antibody detection test for African VL that is highly specific and sensitive.
  • Develop and evaluate an efficient and cost-effective point-of-care parasite test that is capable of detecting parasite products (antigen and/or nucleic acids) in blood, serum or urine. A parasite detection test will allow for differentiating actively infected individuals from those who are not.
  • Evaluate several of the most promising technologies to develop a robust, simple and accurate test of cure for VL.
Development and comparative evaluation of two antigen detection tests for Visceral Leishmaniasis. Vallur AC, Tutterrow YL, Mohamath R, Pattabhi S, Hailu A, Abdoun AO, Ahmed AE, Mukhtar M, Salam MA, Almeida ML, Almeida RP, Mondal D, Albertini A, Ghalib H, Duthie MS, Reed SG. BMC Infect Dis. 2015 Sep 22;15:384. doi: 10.1186/s12879-015-1125-3. PMID:26395447

Specific antibody responses as indicators of treatment efficacy for visceral leishmaniasis. Vallur AC, Hailu A, Mondal D, Reinhart C, Wondimu H, Tutterrow Y, Ghalib HW, Reed SG, Duthie MS. Eur J Clin Microbiol Infect Dis. 2015 Apr;34(4):679-86. doi: 10.1007/s10096-014-2282-9. Epub 2014 Nov 19.PMID:25407374

Vallur AC, Duthie MS, Reinhart C, Tutterrow Y, Hamano S, Bhaskar KR, Coler RN, Mondal D, Reed SG. 2014. Biomarkers for intracellular pathogens: establishing tools as vaccine and therapeutic endpoints for visceral leishmaniasis. Clin Microbiol Infect 20: O374-83

Duthie MS, Guderian J, Vallur A, Bhatia A, Lima dos Santos P, Vieira de Melo E, Ribeiro de Jesus A, Todt M, Mondal D, Almeida R, Reed SG. 2014. Alteration of the serum biomarker profiles of visceral leishmaniasis during treatment. Eur J Clin Microbiol Infect Dis 33: 639-49

LEPROSY DIAGNOSTICS

CHALLENGE

Diagnostics22Current leprosy control strategies are based upon prompt detection and treatment. However, it is estimated that the delay from the time of onset of the first discernible symptom to clinical diagnosis is anywhere from one-three years in more than half of all leprosy patients. In countries where leprosy is extremely rare, patients are often misdiagnosed and mistreated before eventually being properly identified. Such delays can have a dramatic impact on the degree of nerve function impairment and response to treatment.

SOLUTIONS

Leprosy requires better diagnostic and prognostic tools to accompany new strategies aimed at further reducing global and regional burdens. As part of our leprosy program, and in collaboration with industrial partners, we are developing both rapid diagnostic tests for primary leprosy diagnosis and new tools for the objective assessment of treatment.

Our low cost, point-of-care diagnostic enables rapid diagnosis of M. leprae infection up to one year before clinical symptoms appear. This diagnostic, which uses a single drop of blood, is now licensed for use in Brazil.

Use of this diagnostic test, which provides results in less than 10 minutes, will

  • substantially enhance global efforts to diagnose and treat patients quickly
  • significantly prevent clinical symptoms and further spread of the disease
  • dramatically improve the lives of millions of people living with the disease
Multibacillary leprosy patients with high and persistent serum antibodies to leprosy IDRI diagnostic-1/LID-1: higher susceptibility to develop type 2 reactions. Mizoguti Dde F, Hungria EM, Freitas AA, Oliveira RM, Cardoso LP, Costa MB, Sousa AL, Duthie MS, Stefani MM. Mem Inst Oswaldo Cruz. 2015 Nov;110(7):914-20. doi: 10.1590/0074-02760150198. PMID: 26560982

Alterations to antigen-specific immune responses before and after multidrug therapy of leprosy. Freitas AA, Oliveira RM, Hungria EM, Cardoso LP, Sousa AL, Costa MB, Reed SG, Duthie MS, Stefani MM. Diagn Microbiol Infect Dis. 2015 Oct;83(2):154-61. doi: 10.1016/j.diagmicrobio.2015.06.021. Epub 2015 Jul 2. PMID:26233487

Antigen-specific assessment of the immunological status of various groups in a leprosy endemic region. da Conceição Oliveira Coelho Fabri A, Carvalho AP, Araujo S, Goulart LR, de Mattos AM, Teixeira HC, Goulart IM, Duthie MS, Correa-Oliveira R, Lana FC. BMC Infect Dis. 2015 May 30;15:218. doi: 10.1186/s12879-015-0962-4. PMID:26021317

Duthie MS, Balagon MF, Maghanoy A, Orcullo FM, Cang M, Dias RF, Collovati M, Reed SG. 2014. Rapid quantitative serological test for detection of infection with Mycobacterium leprae, the causative agent of leprosy. J Clin Microbiol 52: 613-9

Duthie MS, Raychaudhuri R, Tutterrow YL, Misquith A, Bowman J, Casey A, Balagon MF, Maghanoy A, Beltran-Alzate JC, Romero-Alzate M, Cardona-Castro N, Reed SG. 2014. A rapid ELISA for the diagnosis of MB leprosy based on complementary detection of antibodies against a novel protein-glycolipid conjugate. Diagn Microbiol Infect Dis 79: 233-9

CHAGAS DIAGNOSTICS

CHALLENGE

Chagas disease is caused by the parasite Trypanosoma cruzi, which is transmitted to animals and people by insect vectors and is found only in the Americas (mainly in rural areas of Latin America where poverty is widespread). The disease can also be transmitted by blood transfusion or from mother to baby during pregnancy. It is estimated that as many as 8 million people in Mexico, Central America and South America have Chagas disease, most of whom do not know they are infected. If untreated, infection is lifelong and can be life threatening.

SOLUTIONS

Our scientists focus on better reagents for accurate and rapid diagnostic tests as well as for future vaccines. Tests based on our proprietary recombinant fusion protein, which contains multiple antigenic protein domains from T. cruzi, are currently marketed in the U.S. and in Latin America. These tests were developed in collaboration with corporate partners such as Inbios (Trypanosome Detect™) and support accurate diagnosis of Chagas disease in suspected individuals so that appropriate drug therapy can be initiated.

Our same technology has also been incorporated into a screen to prevent T. cruzi contamination in blood supplies. In May 2010, the U.S. FDA approved the ABBOTT PRISM Chagas assay for screening blood, tissue and organ donors. Blood donations in Latin American countries where Chagas is endemic have undergone screening for many years. Now countries such as the U.S. that have growing immigrant populations from endemic areas are recognizing the threat and recommending testing of all donated blood and tissues.

We continue to develop new antigenic proteins and to collaborate with our corporate partners on improved diagnostic tests to advance patient care as well as to protect our blood and tissue supplies.

Houghton RL, Stevens YY, Guderian J, Okamoto M, Kabir M, Reed, SG, Leiby DA, Morrow WJW, Raychaudhuri S. 2009. Lateral Flow Immunoassay for Diagnosis of Trypanosoma cruzi Infection with High Correlation to the Radioimmunoprecipitation Assay. Clin. Vac. Immunol. 16(4): 515—520.

Ferreira, A.W., Z.R. Belem, E.A. Lemos, S.G. Reed, and A. Campos-Neto. 2001. LemEnzyme-linked immunosorbent assay for serological diagnosis of Chagas’ Disease employing a Trypanosoma cruzi recombinant antigen that consists of four different peptides. J. Clin. Microbiol. 39:4390-4395.

Houghton, R.L., D.R. Benson, L. Reynolds, P. McNeill, P. Sleath, M. Lodes, Y.A.W. Skeiky, R. Badaro, A.U. Krettlie and S.G. Reed. 2000. Multiepitope synthetic peptide and recombinant protein for the detection of antibodies to Trypanosoma cruzi in patients with treated or untreated Chagas’ disease. J. Infect. Dis. 181:325-330.