acid produced when GOT acts on a-ketoglutarate. Other ketone bodies, such as acetoacetic acid, will also couple with the dye, leading to enhanced. SGOT.
KetosisCausing Spurious Elevation of SGOTValues Paul L. Wolf, Claire Langston, Abraham I. Potoisky, and Dorothy J. Williams
In two patients, spurious enhancements of SGOT on SMA 12/60 determination caused erroneous diagnoses
of liver disease,
which
could
have led
to potentially hazardous diagnostic measures. Such errors can be avoided by an ultraviolet spectroscopic
check of suspect
Additional Keyphrases SGOT
#{149}
SMA
12/60
#{149}
SGOT values. ultravioletspectroscopy
of
AutoAnalyzer
This communication concerns two patients in whom spuriously enhanced SGOT (serum glutamic-oxaloacetic transaminase; L-aspartate: 2-oxoglutarate amino-transferase, EC 2.6.1.1), as determined by the SMA
12/60
AutoAnalyzer
(Technicon
Corp.,
Tarrytown,
N.Y. 10591), led to erroneous diagnoses of liver disease. This error can be avoided by checking suspect supranormal SMA 12/60 values by ultraviolet spectroscopy
Case Reports Case 1 A 19-year-old man was admitted to the Statiford Hospital for treatment of diabetic ketoacidosis. Three years before ketoacidosis),
of tests prompted a liver biopsy, the results of which were consistent with a diagnosis of viral hepatitis. Results of further liver-function tests slowly returned to the normally expected values, but on subsequent admissions mined by
this admission abnormal results
for
ketoacidosis,
SMA
(during treatment of liver-function
SGOT activity,
as
deter-
12/60,
was consistently greater than normal. Chronic hepatitis was tentatively diagnosed on this basis, although the results of other liver-function tests were within clinical limits. On the present admission, no abnormalities were seen on physical examination. Laboratory studies showed:
blood glucose, 770 mg/100 ml; serum Na, 136 mmol/ liter; K+, 5.2 mmol/liter; C1, 95 mmol/liter; HC03, 3.5 mmol/liter; and serum acetone positive at 1:8 dilution. An SMA 12/60 screening battery showed an of 180 U. LDH and alkaline phosphatase activities, and the concentration of total bilirubin in serum were within normal limits. SGOT, measured on the same serum sample by ultraviolet spectroscopy, gave a value SGOT
of 45 U.
A 58-year-old-man treatment of chronic
Received
Discussion Both of these patients, who were ketotic because of uncontrolled diabetes mellitus or starvation, had spuriously increased SGOT values as measured by the S1\IA 12/60, but normal values as measured by (the more specific) ultraviolet spectroscopy. Colorimetric determination of SGOT with the SMA 12/60 is based on the coupling reaction of a diazonium salt of N-butyl-4methoxymetanilamide with oxaloacetic acid produced when GOT acts on a-ketoglutarate. Other ketone bodies, such as acetoacetic acid, will also couple with the dye, leading to enhanced SGOT values proportional to the concentration of the acetoacetic (2-5). Spuriously high SGOT values may thus be obtained by this method for cases of diabetic ketoacidosis, starvation, and glycogen storage disease of the liver, plus any other condition in which large amounts of ketone bodies are present in the serum (6). By contrast, the ultraviolet spectroscopic method of determination of SGOT activity is unaffected by ketone bodies; it measures the rate of decrease of NADH in the SGOT rate-dependent coupled reactions (7).
References 1. Henry, ii.J.,Chiomari, N., Golub, 0. J.,and Berkman, S., Revised spectrophotometric methods for the determination glutamic-oxalacetic transaminase, glut amic-pyruvictransaminase, and lactic acid dehydrogenase. Amer. J. Clin. Pathol. 34, (1960).
2. Young,
K., Stewart, measured by the 776 (1969).
SGOT
3.
Sax,
acetic zonium
S. C., and Weitz, S., False elevations SMA 12/60 abstract. CLN. CREM.
S. M., and Moore, J. J., transamina.se salts. CLIN.
activity CHEM.
Determination
of glutamic
by coupling of oxalacetate 13, 175 (1967).
of 381 of
15,
oxalo-
with
dia-
4. Moore, J. J., and Sax, S. M., Serum glutamic oxaloacetic transamina.se using the sequential multiple analyzer (SMA 12/30). CLIN. CHEM. 15, 730 (1969).
Case 2
From the Calif. 94305.
of preoperative laboratory studies, including tests on an SMA 12/60, were within normal limits, except for findings consistent with iron-deficiency anemia. On laparotomy, 38 cm of diseased ileum was resected for bleeding telangiectasia. He developed ketosis and was maintained on intravenous fluids postoperatively. His serum was examined with the SMA 12/60 four days after operation, and showed his SGOT activity to be 100 U. The same sample, analyzed by ultraviolet spectroscopy, showed a value of 8 U. When the patient was again fed orally, the SGOT value by SMA 12/60 returned to normal.
Stanford
was admitted gastrointestinal University
for explanation and bleeding. Results
Medical
Center,
Stanford,
5. Chen, J. C., Marsters, H., and Wieland, IL U., l)iabetic ketosis. Interpretation of elevated serum glutamic oxaloacetic transaminase
31, 1970;
accepted
Jan.
22, 1971.
by multichannel
chemical
6. Cantarow, A., and Trumper, M., ed. W. B. Saunders Co., Philadelphia, 7. Bergmeyer,
Oct.
(sGoT)
analysis.
Diabetes
19, 730 (1970).
ing,
revised.
H. 15., Methods Academic
Press,
of
New
Clinical Biochemistry, Pa., 1962, p 88.
Enzymatic York,
N.Y.,
6th
Analysis, 2nd print1965, p837.
CLINICAL CHEMISTRY, Vol. 17, No. 4, 1971 341
