Apport des examens biochimiques dans le diagnostic de la phase nerveuse de la trypanosomose humaine

The stage of human African trypanosomiasis (HAT) is important to define precisely as far as it is directly related to the type of treatment used. The beginning of the neurological involvement is dif ficult to find out because there is no known specific clinical or biological sign. This study is trying to look for a precise marker and has been realized in Congo. 70 subjects with parasitologically confir med HAT and 70 controls are included. The stage of HAT is determined according to the classical definition on the field using the cerebrospinal fluid (CSF) cell count : less than 5 cells/μl for the first stage (P1), more than 5 cells/μl for the second stage (P2). The blood analysis has included : glucose, urea, creatinine, sodium, potassium, calcium, chloride, phosphorus, uric acid, total bilirubin, uncon jugated bilirubin, total cholesterol, triglycerides, total proteins, aspartate aminotransferase, alanine aminotransferase, creatinine phosphokinase, alkaline phosphatase, gamma-glutamyltransferase, immunoglobulins M and G, C3c fraction of complement, transferrin, seromucoid α1, haptoglobin and albumin. In CSF we have analyzed IgM, IgG, protein levels and the bloodbrain barrier (BBB) impairment. The comparison between the subjects and their controls, the subjects in P1 and in P2, the CSF cell count and the other CSF alterations show the interest of the IgM level in CSF and the BBB impairment to identify subjects in P2. However there is a low gradation in the biological dis turbances and not a precise threshold point. Nevertheless it seems reasonable to raise the CSF cell count level to 20 cells/μl to define the beginning of the nervous involvement.