Limits...
New approaches with different types of circulating cathodic antigen for the diagnosis of patients with low Schistosoma mansoni load.

Grenfell R, Harn DA, Tundup S, Da'dara A, Siqueira L, Coelho PM - PLoS Negl Trop Dis (2013)

Bottom Line: In our previous investigations, the use of crude antigens led to false-positive results.Recently, focus has been given to highly purified Schistosoma mansoni antigens, especially to circulating antigens.Interestingly, the "crude antigen" worked as a good marker for control of cure after praziquantel treatment.

View Article: PubMed Central - PubMed

Affiliation: Schistosomiasis Laboratory, Rene Rachou Research Center, Oswaldo Cruz Foundation (Fiocruz), Belo Horizonte, Minas Gerais, Brazil.

ABSTRACT

Background: Schistosomiasis mansoni is a debilitating and sometimes fatal disease. Accurate diagnosis plays a key role in patient management and infection control. However, currently available parasitological methods are laborious and lack sensitivity. The selection of target antigen candidates has turned out to be a promising tool for the development of more sensitive diagnostic methods. In our previous investigations, the use of crude antigens led to false-positive results. Recently, focus has been given to highly purified Schistosoma mansoni antigens, especially to circulating antigens.

Method: Thus, our main goal was to test different types of circulating cathodic antigen glycoprotein (CCA), as "crude antigen," the protein chain of recombinant CCA and two individual peptides. These schistosome proteins/peptides were tested in a new diagnostic method employing immunomagnetic separation based on the improvement of antigen-antibody binding.

Principal findings: Use of recombinant CCA as a diagnostic antigen allowed us to develop a diagnostic assay with high sensitivity and specificity with no false-negative results. Interestingly, the "crude antigen" worked as a good marker for control of cure after praziquantel treatment.

Conclusions/significance: Our new diagnostic method was superior to enzyme-linked immunosorbent assay in diagnosing low endemicity patients.

Show MeSH

Related in: MedlinePlus

ROC curves of each IMS protocol.In (a) IMS-crude Ag (Aβ€Š=β€Š0.97, p<0.05); (b) IMS-CCAr (Aβ€Š=β€Š0.99, p<0.05); (c) IMS-CCApep1 (Aβ€Š=β€Š0.90, p<0.05); and (d) IMS-CCApep2 (Aβ€Š=β€Š0.94, p<0.05). Artwork created by Prism 5.0 software.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3585039&req=5

pntd-0002054-g003: ROC curves of each IMS protocol.In (a) IMS-crude Ag (Aβ€Š=β€Š0.97, p<0.05); (b) IMS-CCAr (Aβ€Š=β€Š0.99, p<0.05); (c) IMS-CCApep1 (Aβ€Š=β€Š0.90, p<0.05); and (d) IMS-CCApep2 (Aβ€Š=β€Š0.94, p<0.05). Artwork created by Prism 5.0 software.

Mentions: The 50 serum samples selected from people of Pedra Preta, together with the healthy donors' serum samples were screened by IMS using the four different antigens described: sensitized with β€œcrude antigen” (IMS-crude Ag), CCAr (IMS-CCAr), CCA pep1 and CCApep2 (IMS-CCApep1 and IMS-CCApep2). The 53 healthy donors were initially tested for antibodies to schistosomes by ELISA-SWAP and ELISA-SEA. Only one individual was reactive for both antigens and was not therefore removed from the healthy (negative) control group. Further, cut-off value, positivity ratio, sensitivity, and specificity of each IMS methodology were determined by ROC, which are represented in Figure 3.


New approaches with different types of circulating cathodic antigen for the diagnosis of patients with low Schistosoma mansoni load.

Grenfell R, Harn DA, Tundup S, Da'dara A, Siqueira L, Coelho PM - PLoS Negl Trop Dis (2013)

ROC curves of each IMS protocol.In (a) IMS-crude Ag (Aβ€Š=β€Š0.97, p<0.05); (b) IMS-CCAr (Aβ€Š=β€Š0.99, p<0.05); (c) IMS-CCApep1 (Aβ€Š=β€Š0.90, p<0.05); and (d) IMS-CCApep2 (Aβ€Š=β€Š0.94, p<0.05). Artwork created by Prism 5.0 software.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3585039&req=5

pntd-0002054-g003: ROC curves of each IMS protocol.In (a) IMS-crude Ag (Aβ€Š=β€Š0.97, p<0.05); (b) IMS-CCAr (Aβ€Š=β€Š0.99, p<0.05); (c) IMS-CCApep1 (Aβ€Š=β€Š0.90, p<0.05); and (d) IMS-CCApep2 (Aβ€Š=β€Š0.94, p<0.05). Artwork created by Prism 5.0 software.
Mentions: The 50 serum samples selected from people of Pedra Preta, together with the healthy donors' serum samples were screened by IMS using the four different antigens described: sensitized with β€œcrude antigen” (IMS-crude Ag), CCAr (IMS-CCAr), CCA pep1 and CCApep2 (IMS-CCApep1 and IMS-CCApep2). The 53 healthy donors were initially tested for antibodies to schistosomes by ELISA-SWAP and ELISA-SEA. Only one individual was reactive for both antigens and was not therefore removed from the healthy (negative) control group. Further, cut-off value, positivity ratio, sensitivity, and specificity of each IMS methodology were determined by ROC, which are represented in Figure 3.

Bottom Line: In our previous investigations, the use of crude antigens led to false-positive results.Recently, focus has been given to highly purified Schistosoma mansoni antigens, especially to circulating antigens.Interestingly, the "crude antigen" worked as a good marker for control of cure after praziquantel treatment.

View Article: PubMed Central - PubMed

Affiliation: Schistosomiasis Laboratory, Rene Rachou Research Center, Oswaldo Cruz Foundation (Fiocruz), Belo Horizonte, Minas Gerais, Brazil.

ABSTRACT

Background: Schistosomiasis mansoni is a debilitating and sometimes fatal disease. Accurate diagnosis plays a key role in patient management and infection control. However, currently available parasitological methods are laborious and lack sensitivity. The selection of target antigen candidates has turned out to be a promising tool for the development of more sensitive diagnostic methods. In our previous investigations, the use of crude antigens led to false-positive results. Recently, focus has been given to highly purified Schistosoma mansoni antigens, especially to circulating antigens.

Method: Thus, our main goal was to test different types of circulating cathodic antigen glycoprotein (CCA), as "crude antigen," the protein chain of recombinant CCA and two individual peptides. These schistosome proteins/peptides were tested in a new diagnostic method employing immunomagnetic separation based on the improvement of antigen-antibody binding.

Principal findings: Use of recombinant CCA as a diagnostic antigen allowed us to develop a diagnostic assay with high sensitivity and specificity with no false-negative results. Interestingly, the "crude antigen" worked as a good marker for control of cure after praziquantel treatment.

Conclusions/significance: Our new diagnostic method was superior to enzyme-linked immunosorbent assay in diagnosing low endemicity patients.

Show MeSH
Related in: MedlinePlus