Diagnosis of Congenital Toxoplasmosis by Two-Dimensional Immunoblot Differentiation of Mother and Child Immunoglobulin G Profiles

Nielsen, Henrik Vedel; Schmidt, Dorte Remmer; Petersen, Eskild

doi:10.1128/jcm.43.2.711-715.2005

Cited by 25 publications

(19 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Separation of native T. gondii antigen extracts (from the virulent RH strain and the avirulent SSI 119 strain) by twodimensional electrophoresis, followed by immunoblotting, was performed as described by Nielsen et al (18).…”

Section: Methodsmentioning

confidence: 99%

Use of MAG1 Recombinant Antigen for Diagnosis ofToxoplasma gondiiInfection in Humans

Holec

Hiszczyńska-Sawicka

Gasior

et al. 2007

Clin Vaccine Immunol

View full text Add to dashboard Cite

This paper describes the cloning, purification, and serological applications of matrix antigen MAG1 of Toxoplasma gondii. The expression system used allows the production of a large amount of T. gondii recombinant protein, which was assessed for its potential use in an enzyme-linked immunosorbent assay (ELISA) for detection of T. gondii infection in humans. Serum samples from 117 patients with different stages of infection, along with 10 serum samples from seronegative patients obtained for routine diagnostic tests, were used. The results were compared with those of an ELISA that uses a native T. gondii antigen extract. The MAG1 antigen detected antibodies more frequently from the acute stage (97.3%) than from the chronic stage (7.5%) of toxoplasmosis. Hence, this antigen may be used as a tool for detection of T. gondii immunoglobulin G antibodies in persons with acute toxoplasmosis.Toxoplasma gondii (a member of the phylum Apicomplexa) is an ubiquitous protozoan parasite that infects a broad range of hosts, including humans and domestic animals. There are three infectious stages in the life cycle of T. gondii, i.e., the tachyzoite stage; the bradyzoite stage, which occurs in tissue cysts; and the sporozoite stage, which occurs in sporulated oocysts (4). Tachyzoites are involved in propagation within a host, and the other two forms are involved in transmission to new hosts. However, although the ultrastructures of the three stages are similar, there are distinct differences in the phenotypes in the host and in the expression of specific proteins. Several authors have described specific molecular markers associated with both tachyzoites and bradyzoites of T. gondii (7,10). A 65-kDa protein, MAG1, was originally described as being expressed specifically during bradyzoite development because it was localized to the ground substance of the tissue cyst and could be detected in immunoblots of extracts from cysts but not from tachyzoites (21). In 2002, Ferguson and Parmley (6) showed that MAG1 is expressed during both tachyzoite and bradyzoite development and is not a bradyzoite-specific protein. The MAG1 antigen is a very immunogenic protein. High titers of immunoglobulin G (IgG) antibodies against MAG1 are induced in infected humans and pigs (3, 9). Several authors have described the protective effects of MAG1 immunization, as a recombinant protein or as DNA vaccines, in mouse models (19,20). Taken together, these results suggest that matrix antigen MAG1 is particularly promising as a tool for the serodiagnosis of toxoplasmosis in humans.There are two major situations in which the diagnosis of T. gondii infection is of medical importance: first, to detect the transmission of parasites via the placenta from an infected mother to the fetus, and second, to detect the reactivation of a chronic infection in immunocompromised patients. Among the available commercial diagnostic tests, serology is commonly used. The specificities and sensitivities of these serological methods and the differentiation between the phases of t...

show abstract

Section: Methodsmentioning

confidence: 99%

Use of MAG1 Recombinant Antigen for Diagnosis ofToxoplasma gondiiInfection in Humans

Holec

Hiszczyńska-Sawicka

Gasior

et al. 2007

Clin Vaccine Immunol

View full text Add to dashboard Cite

show abstract

“…In the present study, the early diagnosis was greatly supported by the use of the Western blotting assay. This assay compares the immunological profile of mother and infant and allows for differentiation between passively transmitted maternal antibodies and newly synthesized by the infant [16,17] .…”

Section: Commentmentioning

confidence: 99%

“…Up to 90% of infants with congenital infection may appear normal at birth, but are at risk of developing chorioretinitis later, although this has been challenged by other studies [2,4,17,18] . None of the infants in the present study developed chorioretinitis.…”

Section: Commentmentioning

confidence: 99%

Outcome of Toxoplasmosis Acquired during Pregnancy following Treatment in Both Pregnancy and Early Infancy

Galanakis¹,

Manoura²,

Αντωνίου³

et al. 2007

Fetal Diagn Ther

View full text Add to dashboard Cite

Objectives: Congenital toxoplasmosis is associated with clinical dilemmas as untreated infants may have a guarded prognosis and as treatment may induce severe side effects. The aim of this study was to investigate the outcome of infants born to mothers with toxoplasmosis acquired during pregnancy, following administration of appropriate regimens both during pregnancy and early infancy. Study Design: All 35 infants, born to mothers with toxoplasmosis acquired during pregnancy, and referred to the major Neonatal Department in Crete, Greece, during the 7-year period 1997–2003 were included. All neonates were evaluated soon after birth and on a regular follow-up. Results: Almost all mothers received spiramycin from diagnosis through labor and 2 received pyrimethamine and sulfadiazine. At birth, infants had IgG antibody titers ranging from 1/1,350 to 1/109,350. All infants initially received pyrimethamine, sulfadiazine and folinic acid but in only 4 cases treatment was continued beyond the second month of life. Transient neutropenia was commonly observed. A follow-up period of 1.2–8.2 years did not reveal any remarkable sequelae. Conclusions: Our findings suggest that effective treatment both during pregnancy and early infancy is safe and may contribute to a good outcome of infants born to mothers with toxoplasmosis acquired during pregnancy.

show abstract

“…Only the persistence or increase of IgG antibodies within the first 12 months of life can confirm congenital infection in the absence of clinical signs. To overcome this extended time lag between diagnosis and initiation of therapy, several additional tests based on comparison of the mother's immunological profile to that of her child have been developed (8,17,30,(34)(35)(36)38).…”

mentioning

confidence: 99%

Use of Recombinant Antigens for Early Postnatal Diagnosis of Congenital Toxoplasmosis

Buffolano

Beghetto²,

Pezzo

et al. 2005

J Clin Microbiol

Self Cite

View full text Add to dashboard Cite

The main objective of this work was to improve the early serologic diagnosis of toxoplasmosis in children at risk of congenital infection by using recombinant antigens. Serum samples from 104 infants born to mothers with primary Toxoplasma gondii infection acquired during pregnancy, of which 35 were congenitally infected and 22 had clinical silent toxoplasmosis at birth, were included. Immunoglobulin M (IgM), IgG, and IgG subtype antibodies against epitopes carried by fragments of T. gondii MIC2, MIC3, MIC4, M2AP, AMA1, and SAG1 gene products were measured by performing parallel enzyme immunoassays (Rec-ELISAs). Recombinant antigens preferentially reacted with IgG antibodies from infected infants compared to uninfected subjects (P < 0.0001), indicating that sera from infected children recognized a more diverse repertoire of antigens than sera transferred over the placenta from the mothers. Using two serial samples collected within 3 months of life, it was possible to demonstrate a neosynthesis of specific anti-MIC2 and anti-SAG1 immunoglobulin G, mainly of the IgG2 subtype, in 13 out of 20 infants with congenital toxoplasmosis. IgM antibodies in 97% of infected infants reacted with at least one of the recombinant antigens, confirming the diagnosis of congenital infection as soon as 2 months after birth (P < 0.0001). The use of recombinant antigens is effective in distinguishing T. gondii-infected from uninfected infants and shows that assays based on recombinant antigens improve the diagnosis of newborns with congenital toxoplasmosis.

show abstract

Diagnosis of Congenital Toxoplasmosis by Two-Dimensional Immunoblot Differentiation of Mother and Child Immunoglobulin G Profiles

Cited by 25 publications

References 17 publications

Use of MAG1 Recombinant Antigen for Diagnosis ofToxoplasma gondiiInfection in Humans

Use of MAG1 Recombinant Antigen for Diagnosis ofToxoplasma gondiiInfection in Humans

Outcome of Toxoplasmosis Acquired during Pregnancy following Treatment in Both Pregnancy and Early Infancy

Use of Recombinant Antigens for Early Postnatal Diagnosis of Congenital Toxoplasmosis

Contact Info

Product

Resources

About