Time-dependence of urinary neopterin, a marker of cellular immune activity.
Neopterin, a marker of cellular immune system activation, is produced by human macrophages after induction by interferon gamma (secreted by T-lymphocytes) and is eliminated mostly in urine. We have documented the circadian rhythm of urinary neopterin in five healthy young men (about 25 years old), using voidings collected during 48 h at fixed 4-h intervals. We repeated the experiment three times, one week apart. Neopterin was measured by high-performance liquid chromatography (HPLC). We clearly show a peak of the excretion of neopterin in the early morning (around 0630 hours +/- 2 h), with total variability (peak-trough difference) reaching 51%. Neopterin is commonly assayed in urinary fractions, so it is imperative to use urine specimens collected at the same time of day--e.g., the first morning urines--to avoid misinterpretation in follow-up of patients.
Department of Biochemistry, Faculté de Médecine Pitié-Salpêtrière, Paris, France.
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Auzéby
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Bogdan
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Krosi
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Touitou
D000328:Adult; D001708:Biopterins / Q000031:analogs & derivatives* / Q000652:urine; D002851:Chromatography, High Pressure Liquid; D002940:Circadian Rhythm; D003404:Creatinine / Q000652:urine; D006801:Humans; D007111:Immunity, Cellular; D008297:Male; D019798:Neopterin; D012016:Reference Values
D001708:Biopterins; D019798:Neopterin; D003404:Creatinine