Exertional Rhabdomyolysis With Moderate Creatine Kinase Elevation and Marked Transaminase Elevation but Preserved Synthetic Function: A Case Report.

BACKGROUND Rhabdomyolysis is a skeletal muscle injury syndrome characterized by release of intracellular contents into the circulation. Abnormal liver biochemical test results are commonly observed in severe rhabdomyolysis. Most published cases have focused on extreme creatine kinase (CK) elevations (often >30 000 U/L) complicated by fulminant hepatic failure. There is a lack of literature regarding instances in which marked transaminase elevation occurs despite moderate CK elevation. CASE REPORT A 43-year-old man exhibited fatigue, nausea, and myalgia after a 3000-m run. Laboratory tests showed moderate CK elevation but striking transaminase elevation. Peak values were: CK, 2828 U/L; aspartate aminotransferase (AST), 2294 U/L; alanine aminotransferase (ALT), 1554 U/L; AST/ALT ratio, 1.48. Total bilirubin peaked at 34.2 μmol/L, the international normalized ratio was 1.22, and albumin level remained normal. Viral hepatitis serology findings were negative. The patient was diagnosed with exertional rhabdomyolysis; treatment comprised intravenous fluids, urine alkalinization, and hepatoprotective agents. CK and transaminase levels rapidly declined. At discharge on day 8, the patient was asymptomatic (ALT, 339 U/L). At 1 week, ALT had decreased to 79 U/L; all laboratory parameters were normal at 1 year. CONCLUSIONS Exertional rhabdomyolysis can produce marked transaminase elevation despite moderate CK elevation, which may not be linearly correlated with AST and ALT levels. This case documents the unusual phenotype of marked transaminase elevation with preserved synthetic function in a patient showing moderate CK elevation. In selected patients with preserved synthetic function and rapidly declining enzyme levels, conservative management may be appropriate after alternative liver injury etiologies have been excluded.