Serum arginase, a biomarker of treatment efficacy in human African trypanosomiasis.

Arginase serum levels were increased in human African trypanosomiasis patients and returned to control values after treatment. Arginase hydrolyzes l-arginine to l-ornithine, which is essential for parasite growth. Moreover, l-arginine depletion impairs immune functions. Arginase may be considered as a biomarker for treatment efficacy.

Polysomnography as a diagnosis and post-treatment follow-up tool in human African trypanosomiasis: a case study in an infant.

Gambian (Trypanosoma brucei gambiense) human African trypanosomiasis (HAT) evolves from the hemolymphatic stage 1, treated with pentamidine, to the meningoencephalitic stage 2, often treated with melarsoprol. This arseniate may provoke a deadly reactive encephalopathy. It is therefore crucial to diagnose precisely the stages of HAT, especially when clinical and biological examinations are doubtful. We present here the case of a 30-month old girl (E20 KOLNG) diagnosed with stage 1 HAT during a field survey in June 2007 in Congo. She was followed-up every six months for 18 months in a village dispensary facility at Mpouya. Her health status deteriorated in December 2008, although cerebrospinal fluid (CSF) white blood cell (WBC) count was normal. The child was hospitalized at Brazzaville and a daytime polysomnographic recording (electroencephalogram, electrooculogram, and electromyogram) was performed (Temec Vitaport 3® portable recorder) to avoid a new lumbar puncture. The child presented a complete polysomnographic syndrome of HAT with a major disturbance of the distribution of sleep and wake episodes and the occurrence of sleep onset REM periods (SOREMPs). The relapse at stage 2 was confirmed by a new CSF examination that showed an elevated WBC count (23cells·µL(-1)) with the presence of B lymphocytes. Melarsoprol treatment was undertaken. A post-treatment recording was immediately performed, showing the resolution of sleepwake pattern abnormalities. Another polysomnography, taken four months later, confirmed the normalization of sleep-wake patterns indicating healing. We therefore propose that polysomnography, being a non-invasive technique, should be used in children to alleviate burden caused by HAT staging procedures, especially regarding lumbar punctures in remote African villages.

Cerebrospinal fluid B lymphocyte identification for diagnosis and follow-up in human African trypanosomiasis in the field.

OBJECTIVES: In human African trypanosomiasis (HAT, sleeping sickness), staging of disease and treatment follow-up relies on white cell count in the cerebrospinal fluid (CSF). As B lymphocytes (CD19 positive cells) are not found in the CSF of healthy individuals but occur in neurological disorders such as multiple sclerosis, B lymphocyte count may be useful for field diagnosis/staging and therapeutic follow-up in HAT. METHODS: Seventy-one HAT patients were diagnosed and 50 were followed-up 6-24 months after treatment. White cell counts were used for conventional staging (stage 1, < or =5 cells/microl CSF, n = 42; stage 2, > or =20 cells/microl, n = 16) and intermediate stage (6-19 cells/microl, n = 13). Slides containing 1 microl of CSF mixed with Dynabeads CD19 pan B were examined microscopically to detect B cell rosettes (bound to at least four beads). RESULTS: Stage 1 patients exhibited zero (n = 37) or one CSF rosette/microl (n = 5), contrary to most stage 2 patients (14/16: > or =2 rosettes/microl). Intermediate stage patients expressed 0 (n = 9), 1 (n = 3) or 2 (n = 1) rosettes/microl of CSF. During follow-up, rosette counts correlated with white cell count staging but were much easier to read. CONCLUSION: B cell rosettes being easily detected in the CSF in field conditions may be proposed to replace white cell count for defining HAT stages 1 and 2 and limit uncertainty in treatment decision in patients with intermediate stage.