Evaluation of the UBC test in the urine of healthy individuals, patients with benign disorders and urinary bladder cancer.

Using the UBC test, the specificity, sensitivity and prognostic information were evaluated in patients with recently diagnosed transitional cell carcinoma (TCC) and in a control group consisting of apparently healthy individuals and individuals with benign disorders. Frozen urine samples from the 485 individuals in the control group and 100 newly diagnosed TCC patients were analyzed with the UBC test, specific for epitopes on cytokeratin fragments released from the urothelial cells. All the samples were analyzed and corrected for creatinine. No significant concentration difference was found between males and females (p=0.65) and there was no age dependent relation. The median concentration for the entire control group was estimated at 3.7 microg/g and the 95th percentile was calculated at 53.0 microg/g. The apparently healthy individuals in the control group had a median value of 3.4 microg/g with a 95th percentile of 24.3 microg/g. An increased frequency of elevated UBC concentrations was found in some benign disorders e.g., anemia, thyroid disorders, diabetes mellitus, hyperlipemia, urosepsis and cystitis. Patients with superficial tumors exhibited a 66% sensitivity (at 95% specificity), and the UBC concentrations did not differ statistically (p=0.16) from those patients with muscle invasive lesions with a 52% sensitivity. When the UBC concentrations were related to histopathological grade, a significant concentration difference (p<0.004) was found between low grade tumors (sensitivity 41%) and high grade tumors (sensitivity 72%). Survival analysis showed that patient with muscle invasive tumors, high-grade tumors and high UBC concentrations have a significantly reduced survival (five-year survival was estimated to 30%, 35% and 30% respectively) compared to patients with superficial tumors, low-grade tumors or low UBC concentrations (five-year survival, 60%, 85% and 75% respectively). The UBC test showed good accuracy and repeatability. Clinically the test could assist in tumor grading and the detection of recurrent disease, which in turn could assist in treatment selection for the individual patient and possibly improve prognosis.

Cytokeratin 8 and 18 fragments measured in serum and their relation to survival in patients with non-small cell lung cancer.

BACKGROUND: In this study we investigated if the newly developed monoclonal antibodies against Cytokeratin 8 and 18 fragments (Cyk 8/18) have prognostic information in patients with non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: Serum from 69 patients with NSCLC was investigated using a sandwich ELISA, Cyk 8/18, provided by IDL Biotech, Sollentuna Sweden. RESULTS: Cyk 8/18 levels varied between 0.34-14.2 ng/mL, compared with a cut-off value of 1.0 ng/mL for healthy individuals (95% specificity). Using that cut-off value, 80% of NSCLC patients had elevated levels. A statistically significant diminished survival was found for Cyk 8/18 values of 8.0 ng/mL or higher (p = 0.0001). When survival data and Cyk 8/18 levels were analysed according to continuous Cox regression analysis, increased levels of Cyk 8/18 were significantly related to decreased survival (p = 0.016). CONCLUSIONS: The Cyk 8/18 monoclonal antibody had in this study prognostic information regarding survival in patients with NSCLC.

A novel IRMA and ELISA for quantifying cytokeratin 8 and 18 fragments in the sera of healthy individuals and cancer patients.

Cytokeratins 8 and 18 are most frequently co-expressed in simple epithelia and carcinomas. Fragments of these cytokeratins are released into the systemic circulation where they can be quantified and utilized as tumour markers. The present paper reports on a solid-phase sandwich monoclonal immunoassay, considered "epithelial tissue-specific", which recognizes fragments of human cytokeratins 8 and 18 of different sizes (10-50 kD). The evaluated ELISA and IRMA assays exhibited a detection limit of 0.1 microgram 1-1 and characteristically demonstrated a within-assay coefficient of variation (CV) of 1-4% and a between-assay CV of 3-5%. The long-term (300 days) repeatability of lyophilized samples tested in the assay was estimated to have a less than 10% CV. Of apparently healthy individuals, 95% were found to have serum concentrations of less than 0.95 micrograms 1-1. A highly significant difference was found between apparently healthy individuals and pancreatic cancer patients. Patients with metastatic disease showed a sensitivity of 93% and those with local disease 83%, at 95% specificity. This TPAcyk assay revealed good correlation (0.98) with the TPS assay detecting the specific M3 epitope of the tissue polypeptide antigen. The correlation with the long established polyclonal assay of tissue polypeptide antigen (TPA) was estimated to be 0.9.

Evaluation of a new tumor marker for cytokeratin 8 and 18 fragments in healthy individuals and prostate cancer patients.

The serological results from apparently healthy individuals and prostate cancer patients were evaluated with a new assay called TPAcyk ELISA. This assay has a biochemical specificity for fragments of cytokeratins 8 and 18, and exhibits a low within- and between-assay imprecision. The data indicate a significant difference between the results of males and females, but no significant age-dependent relation was found. The cut-off value (95% specificity) for healthy individuals was estimated to be 1.27 ng/mL (n = 190) for males and 0.95 ng/mL (n = 81) for females. When using a cut-off value of 1.27 ng/mL, we found a sensitivity for prostate cancer patients with T2-3 N0M0 of about 20%. For patients with metastatic disease, a sensitivity of 75% was found. A higher sensitivity was obtained with patient sera analyzed with PSA than with TPAcyk, particularly in patients with early stages of the disease. We conclude that the results from this new TPAcyk assay were significantly elevated in patients initially diagnosed with poorly differentiated tumors, that patients with localized tumors exhibited low concentrations, and that patients with metastatic disease showed, on average, 8 times higher concentrations than patients with localized disease. The combination of the TPAcyk and PSA results increased the sensitivity for prostate cancer, particularly in patients with metastatic disease.

The monoclonal anti-cytokeratin-8 antibody, 6d7, targets quiescent cells in prostatic-carcinoma spheroids.

A monoclonal antibody, 6D7, reactive with cytokeratin-8, the most abundant type of cytokeratin in normal and malignant epithelial cells, was examined for its binding in DU 145 prostatic carcinoma spheroids. It was found that 6D7 bound in the intermediate, quiescent cell layers of the spheroids while no binding was observed either in the outer layers, which comprises mainly proliferating cells, or in the central necrotic core of the spheroids. Even within the quiescent cell layers, binding was only observed in certain cells that appeared to have incorporated the anticytokeratin antibody. It is likely that these cells had a disturbance in cell membrane permeability and therefore permitted the transmembrane passage of 6D7. The disturbed cell membrane permeability was due to the local environmental conditions in the spheroids, since quiescent monolayer cells did not incorporate 6D7. A complementary binding of 6D7 and E4, a prostatic carcinoma reactive monoclonal antibody, was found in the DU 145 spheroids. While E4 bound strongly in the outer viable cell layers, 6D7 bound in the quiescent cell layers close to the necrotic core. A combination of radiolabelled 6D7 and E4, therefore appears efficient in targeting both proliferating and quiescent cells.

Immunotargeting with monoclonal cytokeratin 8 antibodies of human urothelial cancer transplanted to nude mice.

The possibility of using cytokeratin antibodies for the radioimmunolocalization of urinary bladder cancer was studied. A monoclonal murine IgG antibody was raised against cytokeratin 8 and labelled with iodine-125; normal murine IgG was used for control purposes. The urothelial cancer cell line RT4 was transplanted into immunodeficient nude mice. The anti-cytokeratin 8 antibody was administered intraperitoneally and its uptake in the tumour and other organs was analyzed with a computerized gamma camera. Optimal scintigraphic visualization occurred 11 days after antibody administration. The tumour/blood ratio of the specific antibody was 5.64 (+/- 5.01 SD) on day 11, compared with 0.73 (+/- 0.35 SD) in the control. Autoradiography demonstrated antibody uptake preferentially in viable sections of the tumour. The antibody uptake is presumed to be the result mainly of binding to the released cytokeratin in and around cells lysed during natural cellular death. The monoclonal murine anti-cytokeratin antibody is of potential interest in studies aimed at improving the clinical staging of urinary bladder cancer.