When is elevated testosterone not testosterone? When it is an immunoassay interfering antibody.

Area of Science:

• Endocrinology
• Hematology
• Clinical Chemistry

Background:

• Hormone level discrepancies can complicate patient diagnosis and treatment.
• Accurate laboratory testing is crucial for effective medical management.
• Acute myelogenous leukemia (AML) presents unique diagnostic challenges.

Observation:

• A patient presented with clinical findings inconsistent with a markedly elevated testosterone (T) level.
• This discrepancy prompted an investigation into the cause of the inaccurate testosterone measurement.

Findings:

• The elevated testosterone level was determined to be a false positive result.
• The cause was identified as heterophile antibodies present in the patient's blood.
• These antibodies originated from a polyclonal gammopathy associated with acute myelogenous leukemia.

Implications:

• This case underscores the need to consider antibody interference in immunoassays.
• Clinicians should be aware of potential laboratory test interferences in patients with hematological malignancies.
• Investigating unexpected laboratory results is vital for accurate diagnosis and appropriate patient care.