The cancer recognition (CARE) antibody test

Area of Science:

• Immunology
• Oncology
• Biochemistry

Background:

• The cancer recognition (CARE) antibody (Ab) test is a serologic assay designed to detect specific IgM antibodies elevated in cancer patients.
• This test utilizes an indirect enzyme-linked immunosorbent assay (ELISA) to measure IgM levels in human serum.
• The assay targets the IgM binding epitope (LT-11) of the CARE antigen (Ag), a synthetically produced 16-mer polypeptide.

Purpose of the Study:

• To evaluate the diagnostic performance of the CARE Ab test in distinguishing cancer patients from healthy volunteers and benign surgical patients.
• To assess the correlation of CARE Ab levels with cancer status, treatment response, and prognosis.

Main Methods:

• Indirect ELISA was employed to measure mean relative concentration (MRC) of CARE Ab in human serum samples.
• Samples were analyzed from healthy volunteers (n=47, n=126, n=24), benign/non-cancer surgical patients (n=27), and cancer patients (n=61).
• Non-parametric analysis was used to compare median MRC values and determine test specificity and sensitivity.

Main Results:

• Healthy volunteers showed median MRC values between 26-46, with specificities ranging from 87-98%.
• Benign/non-cancer surgical patients had a median MRC of 20 and 96% specificity.
• Cancer patients exhibited a significantly higher median MRC of 246 with 89% sensitivity (P < 0.0001 vs. healthy and benign groups).
• Preliminary data indicated decreasing Ab levels correlated with remission, while increasing levels suggested relapse or poor prognosis.

Conclusions:

• The CARE Ab test demonstrates significant potential as a serologic biomarker for cancer detection, showing high sensitivity and specificity.
• The test shows promise in monitoring treatment response and predicting prognosis in cancer patients.
• The IgM antibody is stable and can be reliably measured in both serum and plasma samples.