CPT® Code 87335

1. Indications

The procedure associated with CPT® Code 87335 is indicated for the detection of the Escherichia coli 0157 antigen in patients who present with symptoms suggestive of infection. The following conditions warrant the performance of this test:

• Hemorrhagic Colitis - A severe form of colitis characterized by abdominal pain and bloody diarrhea, often associated with E. coli 0157 infection.
• Hemolytic Uremic Syndrome - A serious condition that can occur following E. coli 0157 infection, leading to kidney failure and other complications.
• Gastrointestinal Symptoms - Patients exhibiting symptoms such as fever, nausea, vomiting, and abdominal cramps that may suggest an E. coli infection.
• Exposure History - Individuals with a known exposure to contaminated food or water sources that may harbor E. coli 0157.

2. Procedure

The procedure for detecting the Escherichia coli 0157 antigen using CPT® Code 87335 involves several key steps, each critical for accurate results:

• Sample Collection - A fecal sample is obtained from the patient. This sample can either be placed in a fixative to preserve its integrity or sent fresh to the laboratory for immediate processing.
• Preparation of the Sample - In the laboratory, the fecal sample is prepared for analysis. This may involve homogenization or dilution to ensure that the antigen is adequately accessible for detection.
• Immunoassay Technique Application - The prepared sample undergoes testing using one of the immunoassay techniques: EIA, ELISA, FIA, or IMCA. Each method utilizes specific antibodies that bind to the E. coli 0157 antigen if present in the sample.
• Detection and Measurement - Following the binding of the antigen to the antibodies, a secondary enzyme-labeled antibody is added. This antibody facilitates a chromogenic reaction, resulting in a color change or fluorescence that indicates the presence of the antigen. The intensity of the color or fluorescence is measured to determine the qualitative or semi-quantitative levels of the antigen.

3. Post-Procedure

After the completion of the immunoassay procedure, the laboratory will analyze the results and report the findings. If the test is positive for Escherichia coli 0157, appropriate clinical follow-up and management should be initiated based on the patient's symptoms and overall clinical picture. It is essential for healthcare providers to interpret the results in conjunction with the patient's clinical history and other diagnostic findings. Additionally, proper handling and disposal of the fecal sample and any materials used during the testing process must be adhered to in order to maintain safety and compliance with laboratory protocols.