Chemiluminescence-based alpha-fetoprotein testing: from laboratory quality control to rational clinical application

Preface: Clinical Coordinates of Alpha-Fetoprotein Testing

Alpha-fetoprotein (AFP) is one of the commonly used tumor markers in clinical practice and holds significant reference value in the auxiliary diagnosis, efficacy evaluation, and recurrence monitoring of hepatocellular carcinoma. AFP assay kits employing chemiluminescence immunoassay have become routinely conducted items in the clinical laboratories of many medical institutions due to their characteristics in sensitivity and linear range.

Technical Features of Chemiluminescence Method

The chemiluminescence method combines immunoreaction with chemiluminescent signal detection, estimating the AFP concentration in a sample through the binding quantity of labeled markers to the target antigen. Such kits are generally based on the double-antibody sandwich principle and are suitable for serum or plasma samples. Compared with traditional radioimmunoassay or enzyme-linked immunosorbent assay methods, the chemiluminescence method demonstrates certain advantages in detection speed, degree of automation, and analytical sensitivity, and can accommodate the testing needs of large-batch samples. Meanwhile, the widespread adoption of fully automated chemiluminescence analysis systems has also provided conditions for reducing manual operation steps.

Auxiliary Value and Boundaries in Clinical Application

Elevated serum AFP levels can be observed in a variety of conditions. In clinical practice, AFP is commonly used for periodic screening in populations at high risk for hepatocellular carcinoma, as well as for auxiliary evaluation of treatment efficacy and monitoring of disease progression trends. It should be clearly understood that AFP is not a specific diagnostic indicator for tumors; factors such as chronic hepatitis, active-phase cirrhosis, pregnancy, and certain reproductive system diseases can all lead to changes in AFP concentration. Therefore, clinicians typically make comprehensive judgments by combining AFP test results with imaging examinations and past medical history, rather than drawing conclusions based on a single numerical value alone.

Quality Control: Ensuring Result Stability and Reliability

When using chemiluminescence AFP assay kits, laboratories should run internal quality control materials before testing and record quality control charts as recommended by the manufacturer, perform calibration at established intervals and evaluate calibration curves, and participate in inter-institutional quality assessment programs to verify the accuracy and comparability of test results. For patients undergoing long-term follow-up, it is recommended that serial testing be completed in the same laboratory using the same method and detection system to reduce result fluctuations introduced by platform differences or lot changes. Standardized sample collection, centrifugation, and storage procedures also directly affect measured values, and laboratories should establish corresponding standardized operating documents.

Conclusion: Focusing on Testing Standards and Reasonable Interpretation

The widespread use of AFP assay kits (chemiluminescence method) provides a convenient auxiliary tool for clinical decision-making. Reasonable use of these kits requires laboratories to strictly control the entire testing process, while the clinical side should pay attention to dynamic changes in results and individual differences. The standardization of testing methods and the prudence of clinical interpretation together constitute the foundation for high-quality tumor marker application.