The soluble 60-kDa tumour necrosis factor receptor: no difference found between patients with relapsing-remitting multiple sclerosis and controls: increasing levels are associated with the recovery from Guillain-Barré syndrome

We determined serum and cerebrospinal fluid (CSF) levels of the soluble 60-kDa tumour necrosis factor (TNF) receptor (sTNF-R p60) in 50 patients with relapsing-remitting multiple sclerosis (MS) and in 18 patients with Guillain-Barré syndrome (GBS). Neither in serum nor in CSF samples was there a statistically significant difference between mean receptor concentrations of patients with MS (serum: 1064, SD 262 pg/ml; CSF: 555, SD 130 pg/ml), with other noninflammatory neurological diseases (serum: 1008, SD 248 pg/ml; CSF: 530, SD 112 pg/ml) and with healthy control subjects (serum: 918, SD 180 pg/ml). In order to determine disease activity, magnetic resonance imaging (MRI) of the brain was performed in all MS patients. The mean sTNF-R p60 levels of patients who showed gadolinium DTPA enhancement on MRI were not different from those without enhancement (1034, SD 274 pg/ml vs 1099, SD 248 pg/ml in serum samples and 546, SD 109 pg/ml vs 565, SD 152 pg/ml in CSF samples). In GBS, the sTNF-R p60 levels of serum and CSF samples were significantly higher than in MS and all control groups except for the group with viral meningitis (VM) (GBS: 1544, SD 834 pg/ml in serum, 882, SD 147 pg/ml in CSF; VM: 1518, SD 375 pg/ml in serum, 1131, SD 611 pg/ml in CSF; P < 0.001 for serum samples and P < 0.005 for CSF samples). Serial serum sTNF-R p60 measurements in 13 patients with GBS showed an increase in receptor levels parallel with the recovery from the disease (1276, SD 374 pg/ml at the time of disease onset, 1554, SD 482 pg/ml 14-24 days later and 1787, SD 525 pg/ml after 28-32 days). From our results and the conflicting data of previous studies, we could not agree with the suggestion that the assessment of sTNF-R p60 in MS patients is a useful marker for disease activity. In GBS, subsequently increasing sTNF-R p60 levels are associated with recovery from the disease. It remains to be shown whether they might represent a relevant pathogenetic factor during this stage of GBS.     

Toxoplasma gondii isolates of free-ranging chickens from Rio de Janeiro, Brazil: mouse mortality, genotype, and oocyst shedding by cats

Most isolates of Toxoplasma gondii can be grouped into 3 genetic lineages. In the present study, 67 isolates of T. gondii were obtained by bioassay in mice inoculated with brains and hearts of 96 asymptomatic chickens from an area highly endemic to human infection in Rio de Janeiro, Brazil. Of the 48 isolates genotyped using the SAG2 locus, 34 (70%) were of type I and 13 (27%) were of type III. No isolate of type II was recovered. Isolates from 1 chicken contained a type I and type III mixed infection, indicating natural multiparasite infection in the same animal. Cats fed mice infected with 11 type I strains shed 19-535 million oocysts in their feces, indicating that type I isolates can circulate in the environment.