Out-licensing

A method to diagnose Chagas disease by detecting serologic antibodies to proteins of the pathogen (2, 3 or 4 proteins depending on the aim). It allows assessing the clinical stage and the response to treatments, and earlier diagnosis in newborns.

Chagas disease is a tropical parasitic disease caused by Trypanosoma cruzi and affecting mainly Central and South America, although reported cases have increased in non-endemic countries. The disease has three clinical stages: 1) Acute, appearing shortly after infection; 2) Asymptomatic; 3) Chronic, associated to cardiac and digestive affections and that may occur years after the infection.
Currently, Chagas disease is diagnosed using serologic commercial methods to detect antibodies to a combination of parasite antigens. These produce only qualitative results (presence/absence) and do not allow assessing the clinical stage or the response to drug treatment (because the antibody levels may remain for a long time, since the parasites killed by the treatment will release more antigens that will result in more antibodies in the blood, and this will balance the diminution achieved by the treatment).
A method to diagnose the disease and assess the response to pharmacological treatment has been developed by CSIC and the University Hospital "Virgen de Arreixaca" (Spain), based on the immunodetection of serological antibodies to four proteins of the parasite:

• KMP11, a highly immunogenic protein found only in kinetoplastids, cell structures typical to some pathogens, including Trypanosoma,
• HSP70, found in all species; antibodies to this HSP70 found in Chagas patients show no cross-reaction with human HSP70,
• PFR2 from the flagellum, highly conserved in trypanosomatide,
• TGP63, a fragment of the GP63 protein of Leishmania infantum, with a role in the interaction parasite - macrophage.

 A different combination of these antigens can be used according to the aim of the assay, with the method requiring the detection of at least two antigens.

The method has been tested in blood samples from healthy persons and Chagas patients. The patients included:

• asymptomatic patients,
• patients suffering of chronic cardiac pathology due to the disease,
• paediatric patients being treated with commercial drugs
• a newborn to a seropositive mother

Main advantages and features

Besides the diagnosis of the Chagas disease, this method allows:

• Determining objectively the clinical stage of the disease
• Assessing the response of the patient to a pharmacological treatment
• Early diagnosis in newborn children, resulting in earlier treatment if required

Early Stage

PCT application filed. The International Search Report showed that the claims aimed at differential diagnostic (distinguishing clinical stage, response to treatment and wether the newborn has been infected after the birth) appeared to be novel and involve an inventive step (i.e. the main claims are likely patentable).

Patent licence (exclusive or non-exclusive, geographically limited or worldwide)

P200930302