Enzyme immunoassay of immunoreactive progastrin-releasing peptide(31-98) as tumor marker for small-cell lung carcinoma: development and evaluation.
Previously, using recombinant human progastrin-releasing peptide (ProGRP)(31-98), we developed a RIA for ProGRP(31-98) and demonstrated that the determination of serum ProGRP(31-98) was a reliable marker for small-cell lung carcinoma (SCLC) (Miyake et al., Cancer Res 1994;54:2136-40). Aiming for a more convenient assay system, we have now developed and evaluated a highly sensitive and specific ELISA for ProGRP(31-98). Only 50 microL of nonextracted serum is needed, and results are obtained in only 2 h. Intraassay and between-day CVs were 1.7-4.6% and 4.2-6.8%, respectively. The log-log calibration curve was linear to 1000 ng/L, and analytical recovery was 91.5-108.7%. The detection limit of this assay, 1.9 ng/L, means that basal concentrations of ProGRP(31-98) were detectable in all healthy subjects. The cutoff value, based on the mean + 3 SD of concentrations in 247 healthy subjects, was set to 45.1 ng/L. Serum concentrations exceeded this value in 18 of 25 SCLC patients, similar to the frequency of increased values found by RIA previously. In contrast, the frequency of increased serum ProGRP(31-98) in patients with nonmalignant pulmonary diseases or non-SCLC was quite low: 0% and 5.0%, respectively. Such results may justify a clinical trial for evaluating this ELISA for the diagnosis and monitoring of SCLC patients.
Aoyagi
K
K
Tonen Corp., Research & Development Laboratory, Saitama, Japan.
Miyake
Y
Y
Urakami
K
K
Kashiwakuma
T
T
Hasegawa
A
A
Kodama
T
T
Yamaguchi
K
K
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal; D001483:Base Sequence; D014408:Biomarkers, Tumor / Q000097:blood*; D001710:Biotin; D018288:Carcinoma, Small Cell / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay / Q000706:statistics & numerical data*; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood*; D008832:Microchemistry; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000097:blood* / Q000737:chemistry / Q000235:genetics; D010455:Peptides / Q000097:blood* / Q000737:chemistry / Q000235:genetics; D011994:Recombinant Proteins / Q000032:analysis / Q000097:blood / Q000737:chemistry / Q000235:genetics; D012016:Reference Values; D012680:Sensitivity and Specificity
D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor; D010446:Peptide Fragments; D010455:Peptides; D011994:Recombinant Proteins; C087079:pro-gastrin-releasing peptide (31-98); D001710:Biotin