title: Diagnosis of toxoplasmosis after allogeneic stem cell transplantation: results of DNA detection and serological techniques.
abstract: BACKGROUND
  The biological diagnosis of toxoplasmosis after allogeneic hematopoietic stem cell transplantation (HSCT) is based on the detection of Toxoplasma gondii DNA in blood specimens or other samples. Serological testing is used mainly to define the immunity status of the patient before HSCT. The aim of our study was to examine the performance of polymerase chain reaction (PCR) and serological techniques in the diagnosis of toxoplasmosis after HSCT.
  
  
  METHODS
  Seventy patients underwent allogeneic HSCT from September 2004 through September 2006. DNA was detected by PCR, and immunoglobulin G and immunoglobulin M were detected by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  The results of immunoglobulin G detection before allogeneic HSCT were positive in 40 (57.1%) of the patients and negative in 30 (42.9%). After HSCT, 57 patients (81.4%) had test results that were negative for immunoglobulin M and had negative results of DNA detection, without toxoplasmosis infection. Four patients (5.7%) had at least 4 samples with positive PCR results and/or test results positive for immunoglobulin M against T. gondii; toxoplasmosis was then confirmed by clinical symptoms. Nine patients (12.9%) with positive PCR results and 1 or 2 samples with test results negative for immunoglobulin M were considered to have asymptomatic T. gondii infection. Reactivation of latent infection was the cause of toxoplasmosis in 3 of the 4 patients, and toxoplasmosis occurred as a primary infection in 1 patient. The detection of specific anti-T. gondii immunoglobulin M was the only biological evidence of toxoplasmosis in 2 patients, and samples were positive for immunoglobulin M before PCR was performed in 1 patient.
  
  
  CONCLUSIONS
  Thus, after HSCT, all patients were at risk for toxoplasmosis; all patients who receive HSCTs should be followed up with biological testing that combines PCR and serological techniques.
authors.affiliation: Parasitologie-Mycologie, Pôle Biologie, Centre Hospitalier Universitaire, Grenoble, France. hfricker-hidalgo@chu-grenoble.fr
authors.forename: Hélène
authors.initials: H
authors.lastname: Fricker-Hidalgo
authors.forename: Claude-Eric
authors.initials: CE
authors.lastname: Bulabois
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Brenier-Pinchart
authors.forename: Rebecca
authors.initials: R
authors.lastname: Hamidfar
authors.forename: Frédéric
authors.initials: F
authors.lastname: Garban
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Brion
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Timsit
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Cahn
authors.forename: Hervé
authors.initials: H
authors.lastname: Pelloux
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D016054:DNA, Protozoan / Q000032:analysis / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D033581:Stem Cell Transplantation / Q000009:adverse effects*; D014122:Toxoplasma / Q000302:isolation & purification*; D014123:Toxoplasmosis / Q000175:diagnosis*; D014184:Transplantation, Homologous / Q000009:adverse effects*
chemical_list: D000913:Antibodies, Protozoan; D016054:DNA, Protozoan; D007074:Immunoglobulin G; D007075:Immunoglobulin M