Transient Macroamylasemia in a Severely Multiple-Handicapped Child Following the Development of Acute Bronchitis

Macroamylasemia is a condition of elevated serum amylase levels in which normal serum amylase form a complex with high molecular weight proteins such as immunoglobulins. This is a case report on a patient with macroamylasemia following acute asthmatic bronchitis. A 5-year-old male with cerebral palsy and developmental retardation was admitted to our hospital because of high fever and severe cough. Treatment of the respiratory symptoms provided symptomatic improvement, but the serum amylase levels became suddenly elevated. Although acute pancreatitis associated with respiratory infection was initially suspected, a predominant salivary isoamylase, normal serum lipase level, low urine amylase level, and low amylase-creatinine clearance ratio (ACCR) (0.58%) indicated macroamylasemia. The serum amylase level decreased, and the ACCR increased within normal range 2 weeks after discharge. Both of these indicators have been within normal range over the past year. Transient macroamylasemia can be misdiagnosed as acute pancreatitis, especially in a severely multiple-handicapped child who is unable to complain. The ACCR is useful in the diagnosis of macroamylasemia.