HE4 Human Epididymis Protein 4 Elisa Test Kit

INTENDED USE

The HE4 assay is an enzyme-linked immunosorbent assay (ELISA) for the in vitro quantitative determination of Human Epididymis Protein 4 (HE4) in human serum. It is further intended to be used in conjunction with CA125 as an aid in estimating the risk of epithelial ovarian cancer in premenopausal and postmenopausal women presenting with pelvic mass.

Summary

Human epididymis protein 4 (HE4) belongs to the family of whey acidic four disulfide core (WFDC) proteins with suspected trypsin inhibitor properties. Other proteins in this family include SLPI, Elafin, and PS20 (WFDC1). The HE4 gene codes for a 13kD protein, although in its mature glycosylated form the protein is approximately 20-25 kD, and consists of a single peptide containing two WFDC domains. HE4 was first identified in the epithelium of the distal epididymis and originally predicted to be a protease inhibitor involved in sperm maturation. HE4 has since been reported to be expressed in several normal tissues including epithelia of respiratory and reproductive tissues and also in ovarian cancer tissue. In addition to expression on a cellular level, secreted HE4 has been detected in high levels in the serum of ovarian cancer patients. In a case/control study comparing patients with ovarian cancer to healthy and benign conditions, Hellström et al. found that HE4 detected ovarian cancer with 67% sensitivity at a specificity level of 96%. In a subsequent study evaluating numerous known biomarkers for ovarian cancer, HE4 showed the highest sensitivity for the detection of ovarian cancer, particularly in early stage disease. In this study, the combination of HE4 and CA 125 was a more accurate predictor of malignancy than either marker alone, with a sensitivity of 76% and a specificity of 95%. Ovarian cancer is the fourth most common cause of cancer-related death in women worldwide. To improve the triage of patients presenting with pelvic mass, the HE4 ELISA may be used in conjunction with CA125 assay as an aid in estimating the risk that the patient is harboring epithelial ovarian cancer. The results must be interpreted in conjunction with other methods in accordance with standard clinical management guidelines. An additional use of the HE4 ELISA is as an aid in monitoring response to therapy for patients with invasive epithelial ovarian cancer. The results should be used in conjunction with other clinical methods used for monitoring ovarian cancer.

Test principle

One-step sandwich principle.

Total duration of assay: 80 minutes.

• Sample, HE4 antibody coated microwells and enzyme labeled monoclonal HE4 antibody are combined.

• During the incubation, HE4 presents in the sample is allowed to react simultaneously with the two antibodies, resulting in the HE4 molecules being sandwiched between the solid phase and enzyme-linked antibodies.

• After washing, a complex is generated between the solid phase, the HE4 within the sample and enzyme-linked antibodies by immunological reactions.

• Substrate solution is then added and catalyzed by this complex, resulting in a chromogenic reaction. The resulting chromogenic reaction is measured as absorbance.

• The absorbance is proportional to the amount of HE4 in the sample.