What condition is monitored by an elevated aldolase (aldolase A) level?

Elevated Aldolase Level (Aldolase A) is Used to Monitor Muscular Dystrophy

Elevated aldolase A level is primarily used to monitor the course of muscular dystrophy (option C).

Aldolase in Muscle Disorders

Aldolase A is one of three isozymes of aldolase (A, B, and C) and is predominantly found in skeletal muscle tissue. Its elevation in serum serves as an important biomarker for monitoring muscle disorders, particularly muscular dystrophy, for the following reasons:

• Aldolase A is expressed at high levels in muscle tissue and leaks into the bloodstream when muscle damage occurs 1
• In muscular dystrophy, ongoing muscle degeneration leads to persistent elevation of serum aldolase A, making it valuable for disease monitoring 1, 2
• Aldolase levels correlate with disease activity in muscular dystrophy and can be used to track progression or response to treatment 2

Differentiating Between Options

Muscular Dystrophy (Option C - Correct)

• Aldolase A elevation is a consistent finding in progressive muscular dystrophy 2
• Aldolase remains robust throughout muscle cell differentiation, making it a reliable marker for monitoring muscle damage in dystrophic conditions 3
• Serum aldolase monitoring helps assess disease activity and treatment response in muscular dystrophy patients 2

Acute Muscle Trauma (Option A - Incorrect)

• While aldolase may be elevated in acute muscle trauma, it is not specifically used to monitor its course
• Creatine kinase (CK) is the preferred marker for monitoring acute muscle trauma due to its greater specificity 4
• Aldolase's role is more valuable in chronic muscle diseases rather than acute trauma 4

Portal Cirrhosis (Option B - Incorrect)

• Aldolase B (not A) is the isozyme that may be elevated in liver disorders 1
• Aldolase activity is only slightly elevated in cirrhosis, making it a poor monitoring marker for this condition 1
• For liver disorders, other enzymes like AST, ALT, and GGT are more commonly used for monitoring 5

Obstructive Jaundice (Option D - Incorrect)

• Aldolase B may be slightly elevated in obstructive jaundice, but is not used for monitoring this condition 1
• For obstructive jaundice, alkaline phosphatase and direct bilirubin are the preferred monitoring markers 5, 6
• There is no established role for aldolase A monitoring in obstructive jaundice 1

Clinical Significance of Aldolase in Muscle Disorders

Aldolase A has unique characteristics that make it valuable for monitoring muscular dystrophy:

• It can be elevated even when CK is normal, potentially identifying muscle damage that might otherwise be missed 4, 7
• It is expressed early in muscle cell differentiation, while CK expression increases later in the differentiation process 3
• Elevated aldolase with normal CK may indicate damage to early regenerating muscle cells, providing insight into disease activity 3

Monitoring Protocol in Muscular Dystrophy

For optimal monitoring of muscular dystrophy:

• Measure both aldolase A and CK levels to get a complete picture of muscle damage 4
• Track trends in aldolase levels over time rather than focusing on isolated measurements
• Consider aldolase elevation in the context of clinical symptoms and disease progression
• Use aldolase measurements to assess response to therapeutic interventions

In conclusion, while aldolase A may be elevated in various conditions affecting muscle, its primary clinical utility for monitoring disease course is in muscular dystrophy.