| dc.description.abstract | Human African trypanosomiasis, or sleeping sickness, is a
parasitic disease endemic in sub-Saharan Africa, transmitted
to humans through the bite of a tsetse fly. The first or
hemolymphatic stage of the disease is associated with
presence of parasites in the bloodstream, lymphatic system,
and body tissues. If patients are left untreated, parasites
cross the blood-brain barrier and invade the cerebrospinal
fluid and the brain parenchyma, giving rise to the
second or meningoencephalitic stage. Stage determination
is a crucial step in guiding the choice of treatment, as drugs
used for S2 are potentially dangerous. Current staging
methods, based on counting white blood cells and demonstrating
trypanosomes in cerebrospinal fluid, lack specificity
and/or sensitivity. In the present study, we used several
proteomic strategies to discover new markers with potential
for staging human African trypanosomiasis. Cerebrospinal
fluid (CSF) samples were collected from patients infected
with Trypanosoma brucei gambiense in the
Democratic Republic of Congo. The stage was determined
following the guidelines of the national control program.
The proteome of the samples was analyzed by two-dimensional
gel electrophoresis (n= 9), and by sixplex tandem
mass tag (TMT) isobaric labeling (n= 6) quantitative mass
spectrometry. Overall, 73 proteins were overexpressed in
patients presenting the second stage of the disease. Two of
these, osteopontin and β-2-microglobulin, were confirmed
to be potential markers for staging human African trypanosomiasis
(HAT) by Western blot and ELISA. The two proteins
significantly discriminated between S1 and S2 patients
with high sensitivity (68% and 78%, respectively) for
100% specificity, and a combination of both improved the
sensitivity to 91%. The levels of osteopontin and β-2-microglobulin
in CSF of S2 patients (µg/ml range), as well as the
fold increased concentration in S2 compared with S1 (3.8
and 5.5 respectively) make the two markers good candidates
for the development of a test for staging HAT patients. | en_US |
