Clinical Implications of Immunohistochemically Demonstrated Lymph Node Micrometastasis in Resectable Pancreatic Cancer

The purpose of this study was to determine the clinical significance of nodal micrometastasis detected by immunohistochemistry in patients that had undergone curative surgery for pancreatic cancer. Between 2005 and 2006, a total of 208 lymph nodes from 48 consecutive patients with pancreatic cancer that had undergone curative resection were immunostained with monoclonal antibody against pan-ck and CK-19. Micrometastasis was defined as metastasis missed by a routine H&E examination but detected during an immunohistochemical evaluation. Relations between immunohistochemical results and clinical and pathologic features and patient survival were examined. Nodal micrometastases were detected in 5 (29.4%) patients of 17 pN0 patients. Nodal micrometastasis was found to be related to tumor relapse (P = 0.043). Twelve patients without overt nodal metastasis and micrometastasis had better prognosis than 5 patients with only nodal micrometastasis (median survival; 35.9 vs 8.6 months, P < 0.001). The Cox proportional hazard model identified nodal micrometastasis as significant prognostic factors. Although the number of patients with micrometastasis was so small and further study would be needed, our study suggests that the lymph node micrometastasis could be the predictor of worse survival and might indicate aggressive tumor biology among patients undergoing curative resection for pancreas cancer.

Cytokeratin Autoantibodies: Useful Serologic Markers for Toluene Diisocyanate-Induced Asthma

To evaluate the clinical significance of autoantibodies to three major epithelial cytokeratins (CK) -- CK8, CK18, and CK19 -- we compared 66 patients with toluene diisocyanate (TDI)-induced asthma (group I) with three control groups: 169 asymptomatic exposed subjects (group II), 64 patients with allergic asthma (group III), and 123 unexposed healthy subjects (group IV). Serum IgG, specific for human recombinant CKs, were measured by ELISA (enzyme linked immunosorbent assay), and ELISA inhibition tests were performed. The existence of these antibodies was confirmed by IgG immunoblot analysis. Anti-TDI-HSA (human serum albumin) IgE and IgG antibodies were measured by ELISA in the same set of the patients. The prevalence of CK8, CK18, and CK19 auotantibodies in group I was significantly higher than in the other three groups. Results of the ELISA inhibition test showed significant inhibition with the addition of three CKs in a dose-dependent manner. No significant association was found between CK autoantibodies and the prevalence of anti- TDI-HSA IgG and IgE antibodies. These results suggest that autoantibodies to CK18 and CK19 can be used as serologic markers for identifying patients with TDI-induced asthma among exposed workers.