PMID- 11192507
OWN - NLM
STAT- MEDLINE
DCOM- 20010125
LR  - 20200306
IS  - 0022-2615 (Print)
IS  - 0022-2615 (Linking)
VI  - 50
IP  - 1
DP  - 2001 Jan
TI  - Evaluation of serological markers for the immunodiagnosis of acute acquired 
      toxoplasmosis.
PG  - 62-70
LID - 10.1099/0022-1317-50-1-62 [doi]
AB  - The detection of specific IgM antibodies has been the most frequently used 
      serological marker for diagnosing recent toxoplasmosis. However, the persistence 
      of specific IgM antibodies in some patients and the use of tests with a low 
      specificity have complicated the interpretation of serological results when 
      toxoplasmosis is suspected. The purpose of the present study was to determine the 
      value of newer serological techniques in the diagnosis of acute acquired 
      toxoplasmosis. Sixty-four sera, 31 from patients with Toxoplasma gondii infection 
      and 33 from patients with latent infection, were tested. Anti-T. gondii IgA was 
      measured by two antibody capture ELISA tests (Platelia Toxo IgA and ETI-TOXOK A) 
      and an automated direct ELISA (IMx Toxo IgA); all three assays detected antibody 
      levels compatible with a recent infection in sera from all 31 patients with acute 
      toxoplasmosis. However, significant levels of IgA were also detected with high 
      frequency by all three assays in sera from patients with latent infection. IgE 
      antibodies detected by IgE immunosorbent agglutination assay (ISAGA) were present 
      in 26 (84%) of 31 patients with acute toxoplasmosis and in sera from two subjects 
      with latent infection taken >1 year after the beginning of the clinical symptoms 
      of infection. Thirty (97%) of 31 patients with a recent T. gondii infection and 
      15 (45%) of 33 subjects with latent infection had an AC/HS pattern compatible 
      with acute toxoplasmosis. The avidity of T. gondii IgG was evaluated by two 
      methods. One method was based on the titration of each serum sample and 
      calculation of the titres, in the absence and presence of urea, in relation to a 
      defined cut-off value. In the other method, a single serum dilution was used and 
      the absorbances of the reactions in the presence and absence of urea were 
      compared. The titration method was more sensitive for diagnosing recent primary 
      infection; all 31 sera from patients with acute toxoplasmosis had avidity indices 
      compatible with acute toxoplasmosis by the titration method, whereas with the 
      single dilution method, sera from four patients had equivocal results. In the 33 
      individuals with latent infection, similar results were obtained with the two 
      avidity methods; only one serum sample had a non-compatible avidity value with 
      the titration method. The results obtained in the present study show that the 
      current serological markers used for diagnosing acute acquired toxoplasmosis have 
      significant limitations. The data suggest that determination of the avidity of T. 
      gondii-specific IgG by the titration method in patients with detectable IgM 
      antibodies defines most accurately the stage of infection by T. gondii.
FAU - Suzuki, Lisandra A
AU  - Suzuki LA
FAU - Rocha, Rosangela J
AU  - Rocha RJ
AD  - Department of Clinical Pathology, Faculty of Medicine and *Department of 
      Parasitology, Insitute of Biology, State University of Campinas (Unicamp), 
      Campinas, Sao Paulo, Brazil.
FAU - Rossi, Claudio L
AU  - Rossi CL
LA  - eng
PT  - Evaluation Study
PT  - Journal Article
PL  - England
TA  - J Med Microbiol
JT  - Journal of medical microbiology
JID - 0224131
RN  - 0 (Antibodies, Protozoan)
RN  - 0 (Biomarkers)
RN  - 0 (Immunoglobulin A)
RN  - 0 (Immunoglobulin G)
RN  - 0 (Reagent Kits, Diagnostic)
RN  - 37341-29-0 (Immunoglobulin E)
SB  - IM
MH  - Acute Disease
MH  - Adolescent
MH  - Adult
MH  - Agglutination Tests
MH  - Animals
MH  - Antibodies, Protozoan/*blood/immunology
MH  - Antibody Affinity
MH  - Biomarkers/blood
MH  - Child
MH  - Enzyme-Linked Immunosorbent Assay/methods
MH  - Female
MH  - Humans
MH  - Immunoglobulin A/blood/immunology
MH  - Immunoglobulin E/blood/immunology
MH  - Immunoglobulin G/blood/immunology
MH  - Immunosorbent Techniques
MH  - Male
MH  - Middle Aged
MH  - Reagent Kits, Diagnostic
MH  - Toxoplasma/*immunology
MH  - Toxoplasmosis/*diagnosis/parasitology
EDAT- 2001/02/24 12:00
MHDA- 2001/02/28 10:01
CRDT- 2001/02/24 12:00
PHST- 2001/02/24 12:00 [pubmed]
PHST- 2001/02/28 10:01 [medline]
PHST- 2001/02/24 12:00 [entrez]
AID - 10.1099/0022-1317-50-1-62 [doi]
PST - ppublish
SO  - J Med Microbiol. 2001 Jan;50(1):62-70. doi: 10.1099/0022-1317-50-1-62.