No abstract

g 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.

Human African trypanosomiasis staging follows human African trypanosomiasis diagnosis (trypanosomes in blood and/or lymph glands, trypanosome-positive). Staging determines treatment, as stage 2 medications are toxic and/or difficult to administer. It relies on cerebrospinal fluid examination: stage 1 (no cerebrospinal fluid trypanosome, trypanosome-negative; white blood cell count ≤5/µl); stage 2 (trypanosome-positive and/or white blood cell count ≥20/µl); intermediate stage (6–19 white blood cell/µl; trypanosome-negative). Lumbar puncture is repeated biannually during the 24-month post-treatment follow-up to confirm cure or detect relapse. Sleep disorders are major at stage 2, with a two-symptom polysomnographic syndrome: sleep–wake circadian disruptions; and sleep-onset rapid eye movement sleep periods. Polysomnography (PSG) was proposed as a noninvasive diagnostic tool, and 24-h PSG recordings were performed throughout a 5-year survey in Congo. Before treatment, 76 patients were included and recorded. Normal sleep–wake patterns occurred in 45 out of 47 stage 1 patients and in 16 out of 19 intermediate-stage patients. PSG syndrome was observed in seven out of ten stage 2 patients. During post-treatment follow-up, PSG syndrome occurrence indicated relapse at stage 2. Thus, noninvasive PSG may represent a valuable alternative for human African trypanosomiasis staging, especially in the post-therapeutic follow-up. The detection of a PSG syndrome would then provoke examination of the patient’s cerebrospinal fluid.