The cancer recognition (CARE) antibody test.
The cancer recognition (CARE) antibody (Ab) test is a serologic assay for a specific IgM that is elevated in cancer patients. All tests are measured using an indirect enzyme-linked immunosorbent assay (ELISA) of human serum. The target polypeptide in the CARE Ab test is the IgM binding epitope (LT-11) of the CARE antigen (Ag) consisting of a 16 mer structure that has been produced synthetically. The mean relative concentration (MRC) is determined relative to standard, normalized human plasma. Non-parametric analysis showed median MRC values of healthy volunteers (HVs) with no history of cancer (n =47), family history of cancer (n = 126) and a previous cancer history (n = 24) to be 26, 34 and 46, respectively. It was determined that there was no significance found among the medians of the three HV groups (P = 0.53). The specificity of the HV types was between 87 and 98%. Benign/non-cancer surgical patients (n = 27) had a median value of 20 with a specificity of 96%. The cancer patients (n = 61) had a median value of 246 with a sensitivity of 89%. There was a significant difference between the HV and cancer patients (P < 0.0001) as well as between the benign/surgical non-cancerous group and cancer patients (P < 0.0001). The IgM antibody is heat stable at room temperature for two days versus being frozen at -80 degrees C (r2 = 0.97). Either serum or plasma samples may be used in the CARE Ab test (r2 = 0.92). The CARE Ab was almost exclusively IgM with no serum conversion to IgG in sequential measurements of patients with cancer over a six-month period. Preliminary data from patients undergoing post-operative cancer treatment showed that decreasing Ab levels revealed patients negative for residual cancer or undergoing remission, while relapsing patients show an increase in Ab levels. A return to a positive Ab level shortly after treatment is a poor prognostic sign while in advanced cancers the Ab levels may be depressed significantly.
Thornthwaite
Jerry T
JT
Cancer Research Institute of West TN at Freed-Hardeman University, 215 Hamlett Street, Henderson, TN 38340, USA. thornthwaite@fhu.edu
McDuffee
Emily C
EC
Harris
Robert B
RB
Secor McVoy
Julie R
JR
Lane
I W
IW
D000912:Antibodies, Neoplasm / Q000097:blood*; D000951:Antigens, Neoplasm / Q000276:immunology*; D014408:Biomarkers, Tumor / Q000097:blood*; D016022:Case-Control Studies; D045744:Cell Line, Tumor / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D016056:Immunodominant Epitopes / Q000276:immunology*; D007075:Immunoglobulin M / Q000097:blood; D009367:Neoplasm Staging; D009369:Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D011379:Prognosis; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods*
D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D016056:Immunodominant Epitopes; D007075:Immunoglobulin M