Platform C: Chol, (tChol), TMAO, Bet, DMG, tHcy, Creat, Crn, Met, MetSo, Cysta, tCys, His, 3-MH, 1-MH, Arg, ADMA, SDMA, hArg, TML
Platform D: PLP, PL, PA, (PAr), PN, Thi, TMP, Ribo, FMN, Cysta, Neopt, Trp, Kyn, (KTR), KA, AA, HK, XA, (HK/XA), HAA, Pic, QA, NA, NAM, mNAM, Cot, OHCot, Trig
What is cystathionine?
Cystathionine is a thioether and an intermediate metabolite of the transsulfuration pathway where homocysteine is converted to cysteine. Both the enzymes responsible for cystathionine formation (cystathionine beta-synthase) and degradation (cystathionine gamma-lyase) are dependent on vitamin B6 (pyridoxal 5'-phosphate).
Cystathionine increases moderately in conditions associated with elevated tHcy (folate and cobalamin deficiencies), markedly in patients with the inborn error, cystathioninuria/cystathionase deficiency, and decreases moderately after intake of vitamin B6 supplements.
Performance of the assay (GC-MS/MS)
Lower limit of detection (LOD): 0.5 nmol/L.
Within-day CV: 2 %; between-day CV: 6 %.
Assessment of homocysteine and one-carbon status. Diagnosis of cystathioninuria/cystathionase deficiency. Cystathionine increases during B6-deficiency.
Specimen, collection and processing
Patient/subject: Prandial status affects concentration, which increases up to 3-fold after a protein rich meal.
Matrix: Serum or EDTA plasma.
Volume: Volume: Minimum volume is 50 µL, but 200 µL is optimal and allows reanalysis.
Preparation and stability: Cystathionine is stable.
Transportation; for general instruction on transportation, click here.
Frozen, on dry ice.
Reported values, interpretation
Reported values: 0.07-0.55 µmol/L
Intraclass correlation coefficient (ICC): 0.63.
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