Clinical Chemistry, Vol 41, 537-543, Copyright © 1995 by American Association for Clinical Chemistry

Enzyme immunoassay of immunoreactive progastrin-releasing peptide(31- 98) as tumor marker for small-cell lung carcinoma: development and evaluation

K Aoyagi, Y Miyake, K Urakami, T Kashiwakuma, A Hasegawa, T Kodama and K Yamaguchi
Tonen Corp., Research & Development Laboratory, Saitama, Japan.

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.

The following articles in journals at HighWire Press have cited this article:

				M. S. Nordlund, D. J. Warren, K. Nustad, J. Bjerner, and E. Paus Automated Time-Resolved Immunofluorometric Assay for Progastrin-Releasing Peptide Clin. Chem., May 1, 2008; 54(5): 919 - 922. [Abstract] [Full Text] [PDF]