IgM quantification in the cerebrospinal fluid of sleeping sickness patients by a latex card agglutination test.
An increased IgM concentration in cerebrospinal fluid (CSF), occurring as a consequence of massive intrathecal IgM synthesis, is a marker of interest for diagnosis of the meningo-encephalitic stage in human African trypanosomiasis. However, in current practice, IgM in CSF is not determined because of the lack of a simple and robust test that is applicable in African rural regions where the disease prevails. We describe the development of a sensitive semiquantitative card agglutination test, LATEX/IgM, for IgM quantification in CSF. The test is simple and fast and the lyophilized reagent remains stable even at 45 degrees C. CSF end-titres obtained with LATEX/IgM parallel the IgM concentrations determined by nephelometry and enzyme-linked immunosorbent assay. Detection of intrathecal IgM synthesis is the most sensitive marker for CNS involvement in sleeping sickness. At a cut-off value of >or= 8, the sensitivity and specificity of LATEX/IgM for intrathecal IgM synthesis are 89.4 and 92.7%. As a consequence, patients with LATEX/IgM end-titres >or= 8 are likely to have intrathecal IgM synthesis, thus central nervous system involvement and therefore should be treated accordingly. Further studies should concentrate on the relationship between the LATEX/IgM end-titres, presence of intrathecal IgM synthesis and occurrence of treatment failures in patients treated with pentamidine.
Lejon
V
V
Department of Parasitology, Institute of Tropical Medicine, Antwerpen, Belgium. vlejon@itg.be
Legros
D
D
Richer
M
M
Ruiz
J A
JA
Jamonneau
V
V
Truc
P
P
Doua
F
F
Djé
N
N
N'Siesi
F X
FX
Bisser
S
S
Magnus
E
E
Wouters
I
I
Konings
J
J
Vervoort
T
T
Sultan
F
F
Büscher
P
P
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood / Q000134:cerebrospinal fluid; D002555:Cerebrospinal Fluid / Q000469:parasitology; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood / Q000134:cerebrospinal fluid*; D007841:Latex Fixation Tests / Q000295:instrumentation / Q000379:methods / Q000592:standards; D009391:Nephelometry and Turbidimetry; D010274:Parasitology / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014347:Trypanosoma brucei gambiense / Q000276:immunology* / Q000302:isolation & purification; D014353:Trypanosomiasis, African / Q000175:diagnosis*
D000913:Antibodies, Protozoan; D007075:Immunoglobulin M