Abstract
γ-Glutamyltransferase (γ-GT) is an early marker for cholestasis and has the capability of glutamine-deamidation. Two infants with elevated serum γ-GT had a decreased serum glutamine. A time course of glutamine and glutamate concentration changes was performed. This revealed a time dependent decrease of glutamine far below the normal lower limit while glutamate increased above the normal upper limit. In conclusion, increased in vitro γ-GT can cause pseudodeficiency of glutamine. To avoid pitfalls, physicians should inform the laboratory on accompanying pathologies.
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Acknowledgments
The authors thank PD Dr. B. Rodeck, Osnabrück, and Dr. J. Uekötter, Münster, for sending the patients samples. Also, the excellent technical help from M. Grüneberg is acknowledged.
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Vermeulen, T., Marquardt, T. & Häberle, J. Pseudodeficiency of glutamine in infant liver disease. Amino Acids 37, 435–437 (2009). https://doi.org/10.1007/s00726-008-0146-2
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DOI: https://doi.org/10.1007/s00726-008-0146-2