In-house quality control and result interpretation of HIV antigen/antibody chemiluminescence detection kits

Basic Laboratory Requirements and Reagent Management

The human immunodeficiency virus antigen and antibody detection kit (chemiluminescence immunoassay) has certain requirements for the laboratory environment: the temperature should preferably be controlled at 18-25°C, the humidity at 30%-70%, and direct sunlight and strong magnetic field interference should be avoided. Before opening, reagents should be stored in a refrigerator at 2-8°C, and before use they need to be equilibrated to room temperature (about 30 minutes). Reagents of different lot numbers must not be mixed, and reagents of the same lot number should be used within the expiration date. In daily operations, the chemiluminescence analyzer should be calibrated regularly, and calibration records should be retained.

Design of Indoor Quality Control Plan

Indoor quality control is a core step in ensuring detection quality. It is recommended to simultaneously set negative, positive, and cutoff value quality control materials during each batch of testing. The negative control should use serum or quality control material from normal individuals known to be HIV-negative, and the positive control may use stabilized quality control material containing HIV antibodies or p24 antigen. Cutoff value quality control materials can be used to monitor changes in the sensitivity of the kit. The luminescence values of the quality control materials should be within the mean and standard deviation range established by the laboratory (usually using the ±2s or ±3s rule). If out of control, factors such as reagents, instruments, and operations need to be investigated, and all specimens must be retested. Quality control chart analysis should be performed at least once a month to evaluate long-term precision.

Interpretation of Results and Cutoff Value Setting

The kit usually uses the ratio of the signal value to the cutoff value (S/CO) as the basis for interpretation. Generally, S/CO >= 1.0 is judged as positive, and S/CO