What laboratory finding is associated with AL amyloidosis?

The association of monoclonal protein on serum or urine immunofixation with AL amyloidosis is a fundamental aspect of the disease's diagnostic criteria. AL amyloidosis, also known as primary amyloidosis, occurs when abnormal light chains of immunoglobulins produced by plasma cells misfold and deposit as amyloid fibrils in various organs. The presence of these monoclonal proteins indicates an underlying plasma cell dyscrasia, which is a key feature of this condition.

When testing for AL amyloidosis, healthcare providers often perform serum and urine protein electrophoresis followed by immunofixation to identify these abnormal proteins. The detection of monoclonal protein helps in confirming the diagnosis and understanding the underlying mechanism of the disease. In contrast, other laboratory findings associated with AL amyloidosis, such as elevated creatinine levels, may reflect organ involvement or dysfunction, but they are not diagnostic markers for the disease itself.

Recognizing the importance of identifying monoclonal protein is essential for diagnosing AL amyloidosis and differentiating it from other conditions that can lead to amyloid deposition.