title: A prospective study of criteria for the diagnosis of toxoplasmic encephalitis in 186 AIDS patients. The BIOTOXO Study Group.
abstract: OBJECTIVE
  To define the factors associated with diagnosis of toxoplasmic encephalitis (TE) in AIDS patients; and to establish a rational procedure for the clinician faced with a decision concerning empiric antitoxoplasma therapy.
  
  
  METHODS
  A 15-month prospective multicentre cohort study in France.
  
  
  METHODS
  One hundred and eighty-six consecutive HIV-positive inpatients undergoing empiric antitoxoplasma therapy for a first episode of presumed TE were monitored. The clinician's initial estimation of the probability of response to antitoxoplasma therapy was recorded. In addition, a validation committee classified cases as TE or non-TE.
  
  
  RESULTS
  Among the 186 patients, the following variables were significantly more frequent in TE (n = 113) than non-TE (n = 73) patients: fever (59% versus 40%). headache (55% versus 33%), seizures (22% versus 11%), suggestive lesions on the brain scan (98% versus 76%), positive Toxoplasma serology (97% versus 71%). Median CD4+ lymphocyte count was significantly higher in TE than in non-TE (27 x 10(6)/l versus 11 x 10(6)/l). The rate of TE in patients on systemic antiprotozoal prophylaxis at entry was 43% as compared with 75% in patients without previous prophylaxis. Pre-therapy estimation of response to empiric therapy was highly correlated with final diagnosis. Multivariate logistic regression analysis showed that the following variables contributed independently to the diagnosis of TE: clinician's estimation of response to treatment at entry > 75%; absence of systemic antiprotozoal prophylaxis; seizures; headache; suggestive lesions on CT or MRI brain scan; and positive Toxoplasma serology.
  
  
  CONCLUSIONS
  A linear logistic model is proposed which uses significant variables, which are readily available. This model gives good accuracy to classify suspected cases of TE.
authors.affiliation: Department of Infectious Diseases, University Hospital, Nantes, France.
authors.forename: F
authors.initials: F
authors.lastname: Raffi
authors.forename: J P
authors.initials: JP
authors.lastname: Aboulker
authors.forename: C
authors.initials: C
authors.lastname: Michelet
authors.forename: V
authors.initials: V
authors.lastname: Reliquet
authors.forename: H
authors.initials: H
authors.lastname: Pelloux
authors.forename: A
authors.initials: A
authors.lastname: Huart
authors.forename: I
authors.initials: I
authors.lastname: Poizot-Martin
authors.forename: P
authors.initials: P
authors.lastname: Morlat
authors.forename: B
authors.initials: B
authors.lastname: Dupas
authors.forename: J M
authors.initials: JM
authors.lastname: Mussini
authors.forename: C
authors.initials: C
authors.lastname: Leport
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000175:diagnosis*; D000328:Adult; D003937:Diagnosis, Differential; D004660:Encephalitis / Q000150:complications / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D011446:Prospective Studies; D014123:Toxoplasmosis / Q000150:complications / Q000175:diagnosis*