Due to depletion of the coating antibody used in the current DHEA ELISA kit, a design change was performed to produce a new DHEA ELISA kit.
The new DHEA ELISA kit will replace the current kit on the implementation date of July 01, 2022, at which time the current DHEA ELISA kit will no longer be available.
Prior to the implementation date, the new DHEA ELISA kit will be available for evaluation purposes (research use only) and will have catalogue number CAN-DH-490 (DC). On the implementation date, the new DHEA ELISA kit will revert to catalogue number CAN-DH-490 and retain the same regulatory approvals as the current kit.
A comparison study was performed between the new (y) and current (x) DHEA ELISA kits using 304 samples. The following linear regression was obtained:
y = 0.93x + 0.26, r = 0.974
A comparison study was performed between the new (y) DHEA ELISA kit and LCMS [Mayo Clinic, Test ID: DHEA_] (x) using 98 samples. The following Passing-Bablock regression was obtained:
y = 0.65x + 0.61, r = 0.923
The reference ranges published by LCMS (Mayo Clinic, Test ID: DHEA_) are higher than the reference ranges established for the prior and new DHEA ELISA kits; this is in line with the slope of the regression being 0.65, but the kits present a highly significant correlation (P < 0.0001).
An analysis of the overall agreement (total agreement percent (TAP)) based on the clinical output of the results between CAN-DH-490 (DC) and LCMS was 94%. This further supports the slope of the correlation concurring with the difference in the reference ranges used in each method.
The main changes between the current and new DHEA ELISA kits are as summarized in the following table:
| Parameter | Current DHEA ELISA | New DHEA ELISA |
|---|---|---|
| Reagents Provided | ||
| Calibrator Volume | A–F: 0.6 mL each | A–F: 1.0 mL each |
| Controls Volume | 0.6 mL each (low & high) | 1.0 mL each (low & high) |
| Assay Procedure | ||
| Total Incubation Time | 75 minutes | 110 minutes |
| Incubation Conditions | Shaking (microplate shaker) | No Shaking |
| Washing Step | 3 x 300 μL/well | 3 x 350 μL/well |
| Performance Characteristics | ||
| The performance characteristics have been updated with the new kit. The main advantages of the new kit are listed below. | ||
| Sensitivity | The sensitivity study was performed according to the CLSI EP17-A2 guideline. | |
| Precision | The precision study was performed based on the CLSI EP05-A3 guideline. | |
| Linearity | The linearity study was performed according to the CLSI EP06-A guideline. | |
| Interferences | Potential interferents were evaluated, including hemoglobin, bilirubin, triglycerides, biotin, HAMAS, rheumatoid factor (RF). | |
| Reference Ranges | Reference ranges of the new kit match closely those of the current kit, and other immunoassay competitors. With the new kit, the ranges for adults were established using a larger number of samples and now include also pediatric cohorts. | |