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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.

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Related in: MedlinePlus

Binding of CCA-specific monoclonal IgG1 antibody to the four CCA antigens.Antigens represented by bars are: SWAP – soluble worm antigen preparation, as the positive control; “crude antigen”; protein chain of recombinant CCA; CCA peptides 1 (BCPred Score = 1) and 2 (BCPred Score = 0.926). Each OD value is representative for the mean of four absorbance values. Statistical differences for comparisons done to BSA are represented by *** (p<0.05) using Student's t test. Artwork created by Prism 5.0 software.
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pntd-0002054-g002: Binding of CCA-specific monoclonal IgG1 antibody to the four CCA antigens.Antigens represented by bars are: SWAP – soluble worm antigen preparation, as the positive control; “crude antigen”; protein chain of recombinant CCA; CCA peptides 1 (BCPred Score = 1) and 2 (BCPred Score = 0.926). Each OD value is representative for the mean of four absorbance values. Statistical differences for comparisons done to BSA are represented by *** (p<0.05) using Student's t test. Artwork created by Prism 5.0 software.

Mentions: Afterwards, two CCA peptides were synthesized based on predicted B cell epitopes. These four CCA were then tested as diagnostic assay candidates, using a monoclonal IgG1 antibody against S. mansoni CCA (lot 5F4.B4, University of Georgia, Monoclonal Antibody Facility, Athens, United States of America). Results are shown on Figure 2 where a significant reaction was seen for all four CCA in comparison to bovine serum albumin (BSA) as our negative control.


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)

Binding of CCA-specific monoclonal IgG1 antibody to the four CCA antigens.Antigens represented by bars are: SWAP – soluble worm antigen preparation, as the positive control; “crude antigen”; protein chain of recombinant CCA; CCA peptides 1 (BCPred Score = 1) and 2 (BCPred Score = 0.926). Each OD value is representative for the mean of four absorbance values. Statistical differences for comparisons done to BSA are represented by *** (p<0.05) using Student's t test. Artwork created by Prism 5.0 software.
© Copyright Policy
Related In: Results  -  Collection

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

pntd-0002054-g002: Binding of CCA-specific monoclonal IgG1 antibody to the four CCA antigens.Antigens represented by bars are: SWAP – soluble worm antigen preparation, as the positive control; “crude antigen”; protein chain of recombinant CCA; CCA peptides 1 (BCPred Score = 1) and 2 (BCPred Score = 0.926). Each OD value is representative for the mean of four absorbance values. Statistical differences for comparisons done to BSA are represented by *** (p<0.05) using Student's t test. Artwork created by Prism 5.0 software.
Mentions: Afterwards, two CCA peptides were synthesized based on predicted B cell epitopes. These four CCA were then tested as diagnostic assay candidates, using a monoclonal IgG1 antibody against S. mansoni CCA (lot 5F4.B4, University of Georgia, Monoclonal Antibody Facility, Athens, United States of America). Results are shown on Figure 2 where a significant reaction was seen for all four CCA in comparison to bovine serum albumin (BSA) as our negative control.

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