Folate, vitamin B-12, and sulfur amino acid levels in patients with renal failure

We examined the plasma profile of sulfur amino acids (SAA) in patients with chronic renal failure (CRF) and looked for any correlation with serum fola te (FA) and/or vitamin B-12. Group 1 comprised 9 patients with CRF and glom erular filtration rate (GFR) >20 ml/min per 1.73 m(2), 9 patients with GFR< 20 ml/min per 1.73 m(2) comprised group 2, and 14 patients on hemodialysis group 3. The control group comprised 16 healthy children. Homocysteine (Hcy ), methionine (Met), cysteine (Cys), and serine (Ser) were measured with ga s chromatography. FA and vitamin B-12 were measured using enzymatic immunoa ssay. Median SAA concentrations were significantly lower in controls than i n the three groups of patients. Hcy concentrations were 0.8 <mu>mol/l in co ntrols versus 5 mu mol/ (group 1), 9 mu mol/l (group 2), and 20 mu mol/l (g roup 3). Met concentrations were 26 mu mol/l in controls versus 26 mu mol/l (group 1), 66 mu mol/l (group 2), and 281 mu mol/l (group 3). Cys concentr ations were 10 mu mol/ in controls versus 98 mu mol/l (group 1), 54 mu mol/ l (group 2), and 122 mu mol/l (group 3). Ser concentrations were 88 mu mol/ in controls versus 153 mu mol/l (group 1), 239 mu mol/l (group 2), and 240 mu mol/l (group 3). The median concentrations of FA were lower in controls than in groups 2 and 3: 5.5 ng/ml versus 8 ng/ml and 15 ng/ml, respectivel y. Vitamin B-12 concentrations did not differ between groups. Vitamin level s did not correlate with SAA. The only difference between patients with Hcy levels in the lower and upper quartile was in Met concentration (38 vs. 26 3 mu mol/l, P<0.02) and GFR (P<0.01). In conclusion, patients with CRF had higher SAA concentrations than healthy children. FA concentrations an highe r in CRF patients than in healthy children but did not correlate with conce ntrations of SAA.