Acute phase proteins: a potential approach for diagnosing chronic infection by Trypanosoma vivax

Abstract

The present study aimed to assess potential changes in acute phase proteins in sheep experimentally infected with Trypanosoma vivax. There were studied eight male sheep, four used as controls and four infected with 10(5) T. vivax trypomastigotes. Blood samples were collected at two points times before infection and then at 5,7, 9, 11, 13, 15, 20, 30, 45, 60, 75, 90, 105 and 120 days post-infection (dpi). Blood samples were centrifuged and allotted, and acute phase proteins were then separated by electrophoresis on acrylamide gel containing sodium dodecyl sulfate. Protein concentrations were determined by computer-assisted densitometry. Total protein was determined by colorimetric biuret method. Trypanosomes were counted daily using a 5 mL aliquot of blood smear on a glass slide under a 22 × 22 mm coverslip. Parasites were counted in 100 microscopic fields (40× magnification), and then multiplied by a correction factor. The results were expressed as parasites per mL of blood. For statistical analyses, we used the Wilcoxon test at 5% significance level. There was found a reduction in several acute phase proteins and increase in antitrypsin and transferrin. This finding can be used for the diagnosis of T. vivax infection, especially in chronic infection.

Acute-phase protein behavior in dairy cattle herd naturally infected with Trypanosoma vivax

“…In the present study, the mean serum concentration of total protein was higher within the NIF group, which can be attributed to the greater production of immunoglobulins against trypanosomes. IgA and IgG were elevated (p < 0.05), which may have been the result of the constant antigenic stimulation that T. vivax causes, due to continuous changes in the expression of surface-variant glycoproteins (Lalor et al, 1984) Ceruloplasmin, a copper carrier protein that acts toward oxidation of ferrous ions and has antioxidant and anti-inflammatory activity (Murata et al, 2004), was significantly reduced in the NIF group, consistent with previous observations among sheep experimentally infected with T. vivax (Almeida et al, 2012). Cattle infected with Anaplasma marginale showed higher levels of ceruloplasmin during the acute phase (Nazifi et al, 2012), thus allowing differentiation between these two diseases.…”

“…However, sheep experimentally infected with T. vivax in the chronic phase (Almeida et al, 2012) and rats infected by T. evansi (Da Silva et al, 2013) showed higher levels of this protein, thus behaving typically as a positive APP (Murata et al, 2004). Despite this classification, in the present study, transferrin levels were lower.…”

“…Antitrypsin was detected only in the NIF group, which was also observed by Almeida et al (2012) in the chronic phase of experimental infection with T. vivax in sheep. This APP may inhibit proteases from Trypanosoma sp., such as cruzipain, cathepsin L and cathepsin B, which are related to tissue damage (Abdulla et al, 2008;Nikolskaia et al, 2006).…”

“…In ruminants, the major APPs are serum amyloid A, haptoglobin, lipopolysaccharide-binding proteins and ␣1-acid glycoprotein (Ceciliani et al, 2012). According to Almeida et al (2012) and Costa et al (2010), the electrophoresis profile of serum proteins from animals that are naturally infected by Trypanosoma sp. indicates that APPs can aid in diagnosing this hemoprotozoon and providing better understanding of the host-parasite relationship, even in the chronic phase of infection.…”

Acute phase proteins in sheep and goats – function, reference ranges and assessment methods: An overview

“…Other important role of Hpx is to bind nitric oxide (Shipulina et al, 1998) and carbon monoxide (Shaklai et al, 1981) and thus to neutralise their toxicity. Information concerning Hpx in small ruminants is limited but there are some data about its behaviour during protozoan diseases (Sousa Almeida et al, 2012).…”