From: young@serum.kodak.com
Newsgroups: sci.med
Subject: Re: GGT
Date: 25 Aug 92 20:50:16 GMT
Article-I.D.: pixel.1992Aug25.205016.19445
Reply-To: young@serum.kodak.com
Distribution: usa
Organization: Clinical Products Division, Eastman Kodak Company
Originator: young@sasquatch

In article <1992Aug25.104747.22709@cbfsb.cb.att.com> fgn@cbnewsb.cb.att.com (frank.g.neves) writes:

[...]

>In the same vein, can anyone supply any valid information relative to 
>elevated ALT levels?

   From "Fundamentals of Clinical Chemistry", Norbert W. Teitz, Ph.D., editor:

	   Transaminases are widely distributed in human tissues.  Both
	AST (aspartate aminotransferase; aspartate transaminase) and ALT
	(alanine aminotransferase; alanine transaminase) are normally
	present in human plasma, bile, cerebrospinal fluid, and saliva,
	but none is found in urine unless a kidney lesion is present.
	   In VIRAL HEPATITIS and other forms of liver disease associated
	with hepatic necrosis, levels of serum AST and ALT are elevated
	even before the clinical signs and symptoms of disease, such as
	jaundice, appear.  Activities for both enzymes may reach values
	as high as 100 times the upper reference limit, although 20- to
	50-fold elevations are most frequently encountered.  Peak values
	of transaminase activity are seen between the seventh and twelfth
	days; values return to normal levels by the third to fifth week
	if recovery is uneventful.  In toxic or viral hepatitis, ALT is
	characteristically as high as or higher than AST, and the ALT/AST
	(De Ritis) ratio, which normally is <1, approaches or becomes 
	greater than unity.
	   Moderately increased levels of AST and ALT activity may also
	be observed in EXTRAHEPATIC CHOLESTASIS.  Levels observed in
	CIRRHOSIS vary with the status of the cirrhotic process; they
	range from upper normal to some four or five times normal, with
	the level of AST activity higher than that of ALT activity.  Five-
	to ten-fold elevations of the two enzymes may occur in patients
	with primary or metastatic CARCINOMA OF THE LIVER, with AST usually
	being higher than ALT, but levels are often normal in the early
	stages of malignant infiltration of the liver.  Slight or moderate
	elevations of both AST and ALT activities may be observed after
	intake of alcohol, during delirium tremens, and after administration
	of drugs such as opiates, salicylates, or ampicillin.
	   Although serum levels of both AST and ALT become elevated when-
	ever disease processes affect liver cell integrity, ALT is the more
	liver-specific enzyme [1].  Serum elevations of ALT are rarely
	observed in conditions other than parenchymal liver disease.
	Moreover, elevations of ALT activity persist longer than do those
	of AST activity.
	   After MYOCARDIAL INFARCTION an increased level of AST activity
	appears in serum...ALT levels are within normal limits, or are
	only marginally increased, in uncomplicated myocardial infarction,
	since the concentration of ALT in heart muscle is only a fraction
	of that of AST.  However, ALT is increased in liver damage secondary
	to heart failure.
	   AST and occasionally ALT activity levels are increased in
	PROGRESSIVE MUSCULAR DYSTROPHY and DERMATOMYOSITIS, reaching levels
	up to eight times normal; they are usually normal in muscle diseases
	of neurogenic origin.  PULMONARY EMBOLI can raise AST levels to two
	to three times normal, and slight to moderate elevations (two to
	five times normal) are seen in ACUTE PANCREATITIS, CRUSHED MUSCLE
	INJURIES, GANGRENE, and HEMOLYTIC DISEASE.

	[1] Ellis, G., Goldberg, D. M., Spooner, R. J., et. al.: Serum
		enzyme tests in diseases of the liver and biliary tree.
		AM. J. CLIN. PATHOL., 70:248-258, 1978.


-Rich Young (These are not Kodak's opinions.)
Newsgroups: sci.med