Ornithine carbamoyltransferase (OTC) deficiency is a urea cycle disorder that causes the accumulation of ammonia, which can lead to encephalopathy. Adults presenting with hyperammonemia who are subsequently diagnosed with urea cycle disorders are rare. Herein, we report a case of a late-onset OTC deficient patient who was successfully treated with arginine, benzoate and hemodialysis. A 59-yr-old man was admitted to our hospital with progressive lethargy and confusion. Although hyperammonemia was suspected as the cause of the patient's mental changes, there was no evidence of chronic liver disease. A plasma amino acid and urine organic acid analysis revealed OTC deficiency. Despite the administration of a lactulose enema, the patient's serum ammonia level increased and he remained confused, leading us to initiate acute hemodialysis. After treatment with arginine, sodium benzoate and hemodialysis, the patient's serum ammonia level stabilized and his mental status returned to normal.
Age of Onset ; Ammonia/blood ; Arginine/therapeutic use ; Citrulline/blood ; Humans ; Hyperammonemia/*etiology ; Male ; Middle Aged ; Ornithine/blood ; Ornithine Carbamoyltransferase Deficiency Disease/complications/*diagnosis/drug therapy ; Pedigree ; Renal Dialysis ; Sodium Benzoate/therapeutic use

OBJECTIVETo study the role of carbamyl phosphate I (CPS-I)and ornithine transcarbamoylase (OCT) levels in cirrhosis patients with and without hepatic encephalopathy, and to analyze the correlations between CPS-Iand OCT with the development of hepatic encephalopathy.

METHODSCPS-I, OCT, plasma ammonia and liver function of 95 cirrhosis patients with hepatic encephalopathy and 25 cirrhosis patients without hepatic encephalopathy in our hospital from January 2008 to December 2009 were analyzed. 60 healthy controls were recruited in the control group. The differences of serum CPS-I, OCT levels among the cirrhosis patients with and without hepatic encephalopathy and the healthy controls were analyzed; the correlations of CPS-I, OCT levels with plasma ammonia and total protein in cirrhosis patients,and the correlations of CPS-I, OCT levels with Child-Pugh classification of cirrhosis symptom severity in cirrhosis were analyzed. the clinical characteristics between patients who had HE and no HE with chi-square tests were compared. Comparisons of CPS-I, OCT levels across patients based on the Child-Pugh classification were performed with One-Way ANOVA and Student-Newman-Keuls, correlation of CPS-I, OCT with other indicators were performed with Pearson correlation analysis.

RESULTSSerum CPS-I and OCT levels in cirrhosis patients with hepatic encephalopathy were (143.3+/-48.5) U/L, (297.0+/-102.6) is multiplied by 10 U/L, which were lower than that in cirrhosis patients without hepatic encephalopathy (180.3+/-51.5) U/L, (351.8+/-109.0) is multiplied by 10 U/L (t = 2.53, t = 2.78, P < 0.01). Compared with healthy controls, serum CPS-I and OCT levels in cirrhosis patients with and without hepatic encephalopathy were all lower (t = 3.21, t = 4.16, t = 2.12, t = 3.15, P < 0.05). CPS-I was correlated with OCT, (r = 0.946, P < 0.05); CPS-I and OCT were negatively correlated with ALT and AST (r = -0.284, r = -0.239, r = -0.303, r = -0.322, P < 0.05). Additionally, CPS-I and OCT levels were negatively correlated with the Child-Pugh classification in Cirrhosis (F = 10.13, F = 20.28, P < 0.01).

CONCLUSIONThe serum CPS-I and COT levels were important factors affecting plasma ammonia in patients with cirrhosis and played an important role in the development of hepatic encephalopathy.

Adult ; Ammonia ; blood ; Carbamoyl-Phosphate Synthase (Ammonia) ; metabolism ; Case-Control Studies ; Female ; Hepatic Encephalopathy ; blood ; enzymology ; Humans ; Male ; Middle Aged ; Ornithine Carbamoyltransferase ; metabolism