The expression of six sialylated carbohydrate antigens (CA19-9, CA-SO, SLEX, SLX, DU-PAN-2, 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 Le" (SLEX) and SLX, belonging to type I1 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 I1 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-:! 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. Key Words: Sialylated carbohydrate antigen-Pancreatic cancer-CA19-%Sialyl SSEA-1 (SLXtDU-PAN-2- There have been no useful tumor markers for pancreatic cancer except for carcinoembryonic antigen (CEA). However, many of the recently developed tumor antigens detected by monoclonal antibodies (MoAbs) against various adenocarcinomas Manuscript

DU-PAN-2 is a high-molecular-weight glycoprotein defined by a murine monoclonal antibody (MAb) against a pancreatic ductal adenocarcinoma cell line. In order to evaluate the usefulness of this antigen as a tumor marker, we determined the serum level of the antigen by competitive inhibition radioimmunoassay in sera from 139 patients with various malignant tumors, chiefly digestive cancers, 98 patients with different benign diseases and 11 healthy subjects. Values in the healthy subjects were less than 100 U/ml. Levels above 100 U/ml were frequently observed in sera from benign diseases, but levels above 400 U/ml were found in only 6 of the patients with benign diseases. In contrast, levels exceeding 400 U/ml were detected in 72% of patients with pancreatic cancer, 44% of patients with hepatocellular cancer and 40% of patients with biliary tract cancer. The positivity was low in other cancers such as gastric cancer (19%) and colorectal cancer (7%). Serum levels of CEA and CA 19-9 were also determined in cancer patients. Among the pancreatic cancer patients studied, values above 400 U/ml were found in 5 of the 8 CEA-negative patients (less than 5 ng/ml) and 2 of the 3 CA 19-9 negative patients (less than 37 U/ml). These results indicate that determination of the serum DU-PAN-2 can aid in serological diagnosis of cancer of the digestive tract, more particularly of the pancreas.

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.

A 42-year-old womanwith autosomal dominant polycystic kidney disease (ADPKD) was admitted to our hospital on April 29, 1999, with complaints of abdominal pain. A diagnosis of intestinal obstruction wasreached on the basis of clinical findings and X-ray evidence. A computed tomography scan of the abdomenshowed massively enlarged kidneys, especially the right kidney, which seemed to compress the small intestine. The patient underwent percutaneous aspiration of the largest cysts on the surface of the right kidney. The symptoms, in this rare case of intestinal obstruction by an enlarged kidney in ADPKD, were alleviated the day after the aspiration procedure. (Internal Medicine 41: 441-444, 2002)

In 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.