Yasuhiro Takemori

Expression of various sialylated carbohydrate antigens in malignant and nonmalignant pancreatic tissues.

The expression of six sialylated carbohydrate antigens (CA19–9, CA-SO, SLEX, SLX, DU-PAN-2, ST-439) was examined in malignant and nonmalignant pancreatic tissues using an immunohistochemical method to elucidate the characteristics of these carbohydrate antigens as tumor markers. All carbohydrate antigens except for sialyl SSEA-I (SLX, 52.4%) were expressed in more than 80% of the pancreatic cancer. CA19–9 and CA-50, belonging to type I blood group antigens, and DU-PAN-2 and ST-439 were localized predominantly in the cytoplasm of cancer cells, while sialyl Lex (SLEX) and SLX, belonging to type II blood group antigens, were stained mainly on the apical membranes of malignant glands. Although type I antigens were expressed in most nonmalignant pancreatic tissues, the type II antigens and ST-439 were absent in almost all of the normal tissues and faintly expressed in few chronic pancreatitis tissues, suggesting the high tumor specificity of these antigens. Each antigen was expressed on the apical surface of ducts in normal pancreas. However, in about 30% of chronic pancreatitis cases, type I antigens and DU-PAN-2 were observed in the cytoplasm of ductal cells. All patients showing stromal stain, possibly caused by loss of antigen polar expression and shedding into the surrounding stroma adjacent to malignant glands, revealed high levels of serum antigen. This finding suggests that the stromal appearance of antigens is a significant factor in the elevation of serum antigen levels.

Diagnostic significance of cancer-associated carbohydrate antigen (CA19-9) concentrations in pancreatic juice: analysis in pure pancreatic juice collected by endoscopic aspiration and immunohistochemical study in chronic pancreatitis.

This study evaluated the diagnostic significance of concentrations of the cancer-associated carbohydrate antigen CA 19–9 in pure pancreatic juice (PPJ) collected by endoscopic cannulation. We also attempted to elucidate the features and source of the increased CA 19–9 concentration found in the pancreatic juice of patients with chronic pancreatitis (CP) by means of immunohistochemical staining. The mean output as well as the mean concentration of CA 19–9 in each of the four fractions collected was highest in patients with pancreatic cancer (PC) and also was elevated significantly in patients with CP compared with controls. However, CA 19–9 concentrations were not elevated in patients with cholecystolithiasis. When the cutoff value was set as the mean concentration + 2SD of the controls, significantly elevated concentrations of CA 19–9 were found in the third fraction (secretory phase) in 90% of the patients with PC and 66% of the patients with CP. Immunohistochemical staining revealed that CA 19–9 was expressed more widely in the ductal cells of CP tissues than in those of normal pancreatic (NP) tissues, with CP tissue showing more CA 19–9-positive ductal cells per area than NP tissues. In NP tissue, CA 19–9 was localized to the apical surface and supranuclear regions (apical type) in all the ductal cells stained by the antigen, while ∼50% of cases with CP exhibited a cytoplasmic pattern showing a loss of polarity of the antigen expression. Moreover, this cellular localization pattern was more pronounced in the small ducts that had proliferated and aggregated following the destruction of lobules in CP. These results indicate that although increased concentrations of CA 19–9 in PPJ have no cancer specificity, measurement of CA 19–9 in PPJ can be used as a sensitive marker for some pancreatic disorders, and higher CA 19–9 concentrations in the pancreatic juice of patients with CP may reflect the strong expression of CA 19–9 in the proliferating small ducts associated with CP.

Utility and limitations of a method for detecting Helicobacter pylori-specific antigens in the stool

Background: Recently, a method for detecting Helicobacter pylori-specific antigens in the stool (HpSA) has been proposed to be useful clinically. The aim of this study was to determine the accuracy of HpSA for the diagnosis of H. pylori infection, including early assessment after eradication treatment, and the potential for quantitative evaluation of H. pylori in the stomach. Methods: The subjects were 85 patients with gastroduodenal disorders who underwent endoscopic examination. Of these, 36 were treated for eradication of H. pylori infection and reassessed 4–8 weeks after treatment. HpSA was tested by enzyme immunoassay. For the definitive diagnosis of H. pylori infection, biopsy specimens were taken endoscopically and examined by quantitative culture, rapid urease test, and immunohistostaining. In addition, serum antibody against H. pylori was tested before the eradication treatment and a 13C-urea breath test was conducted after treatment. The results of these reference tests were compared with those obtained by HpSA. Results: The sensitivity and specificity of HpSA were 90.4% and 100% before eradication treatment and 57.1% and 100% after the treatment. There was a positive correlation between the optical density of HpSA and the number of H. pylori bacilli evaluated by quantitative culture. Conclusions: The HpSA test is considered to be an accurate method for the diagnosis of H. pylori infection, with high specificity. However, there may be problems of false negativity if HpSA is used for the early assessment of treatment efficacy. Furthermore, HpSA is suggested to have potential for the quantitative evaluation of H. pylori status in the stomach.

Factors affecting serum levels of CA 19-9 with special reference to benign hepatobiliary and pancreatic diseases

SummaryIn order to elucidate the factors affecting the serum levels of CA 19-9, we analyzed sera of 79 patients with pancreatic cancer and 169 with non-malignant diseases, chiefly consisting of hepatobiliary and pancreatic diseases. Serum CA 19-9 values in patients with pancreatic cancer had no relation to the location of the tumor or presence of jaundice. Similarly, no tendency was observed as to the location and size of tumor or to the grade of differentiation in 12 CA 19-9-negative patients with pancreatic cancer. Serum levels of CA 19-9 in patients with cholelithiasis complicated by cholangitis frequently showed markedly high values, but then rapidly normalized in parallel with the subsiding of inflammation. The behaviour of serum CA 19-9 showed little relation to renal or hepatic failures or to intrahepatic cholestasis. However, slightly elevated levels of the antigen were found in more than half of those patients with fulminant hepatitis showing massive necrosis. In chronic pancreatitis, the prevalence was only 8%; however, an increase was observed at the time of exacerbation in 2 of 5 positive patients. There was hardly any increase in serum levels of CA 19-9 after endoscopic retrograde cholangiopancreatography (ERCP), although serum levels of pancreatic enzymes rose after ERCP in almost all patients. Thus, it appears that CA 19-9 does not easily escape into the bloodstream, unlike pancreatic enzymes.

Novel diagnostic method of testing for Helicobacter pylori infection using the rapid leukocyte strip test, Leukostix

Background and Aim:  A characteristic of gastric mucosa infected with Helicobacter pylori is infiltration of inflammatory cells, mainly consisting of neutrophils. The present study aimed to detect neutrophils in homogenates of biopsied gastric mucosa semiquantitatively using the rapid leukocyte strip test, Leukostix. The authors then investigated the association of these results with H. pylori status.

Evaluation of Cancer‐Associated Carbohydrate Antigen (NCC‐ST‐439) Measurement in Pure Pancreatic Juice Collected by Endoscopic Aspiration

Abstract: This study was undertaken to elucidate the diagnostic significance of the measurement of a cancer‐associated carbohydrate antigen, NCC‐ST‐439 (ST‐439), in pure pancreatic juice collected by endoscopic cannulation, chiefly from patients with pancreatic diseases.

Abstracts of Selected Papers Presented at the 31st Annual Meeting of the Japanese Society of Gastroenterology

S OF SELECTED PAPERS PRESENTED AT THE 31ST ANNUAL MEETING OF THE JAPANESE SOCIETY OF GASTROENTEROLOGY October 5-7, 1989, Asahikawa, Japan Chairman: Masayoshi NAMIKI, M.D.