Potential for differential diagnosis of autoimmune pancreatitis and pancreatic cancer using carbonic anhydrase II antibody.

OBJECTIVES: Pancreatic ductal epithelia contain an abundance of carbonic anhydrase (CA), and the presence of antibodies to this enzyme has been described in autoimmune disorders. We previously found a small amount of an immunoglobulin G-like material in purchased CAII reagents, which led to pseudopositive reactions. METHODS: We determined the optimum measurement conditions for detecting anti-CAII antibody using an enzyme-linked immunosorbent assay and sera from 140 patients with pancreatic diseases. RESULTS: Compared with the prevalence of anti-CAII antibody in healthy subjects, a significantly higher seroprevalence of the antibody was detected in patients with autoimmune pancreatitis (AIP) (88.9%, P < 0.02), Sjögren syndrome (67.6%, P < 0.01), and alcoholic chronic pancreatitis (45.8%, P < 0.01). No positive results were obtained among patients with pancreatic cancer. Moreover, the antibody value obtained in the pancreatic cancer patients was actually lower than that obtained in healthy subjects. CONCLUSIONS: The anti-CAII antibody is probably not a specific marker of AIP because it was present at a higher frequency in the sera of patients with other pancreatic diseases. Nevertheless, the anti-CAII antibody may be a useful tool for the differential diagnosis of AIP and pancreatic cancer.

Recruitment of immature neutrophils in peripheral blood following leukocytapheresis therapy for rheumatoid arthritis.

The objective of this study is to evaluate the cellular mechanism underlying filtration leukocytapheresis (LCAP) therapy for the treatment of rheumatoid arthritis (RA). Thirteen patients with refractory RA each underwent three sessions of LCAP. Before (pre-) and after (post-) the completion of the first LCAP session, peripheral blood was sampled and analyzed for neutrophil surface markers using flow cytometry. The surface antigens of peripheral blood mononuclear cells (PBMCs) and neutrophils obtained at pre- and post-LCAP were then analyzed using a fluorescence-activated cell sorter. The American College of Rheumatology's criterion of a 20% improvement was achieved in six patients, but not in the other seven patients, after LCAP therapy. The post-LCAP number of blood band form neutrophils with a bone marrow phenotype (CD49d(dim+), low density) was higher among the responders than among the nonresponders, suggesting an association between the clinical response and the recruitment of bone-marrow-derived neutrophils. After the nonspecific absorption of WBCs during a 1-h Cellsorba procedure, the number of PBMCs was consistently decreased, although the number of neutrophils that were affected by removal plus recruitment varied in a manner that was independent of efficacy. In contrast, the emergence of immature neutrophils in the peripheral blood was characteristic of the effective therapies. These cells were found after the 1st session of responders and also found following sessions of LCAPs. Immature neutrophils, which may be recruited from the bone marrow in the peripheral blood after the first session of LCAP, can predict the clinical efficacy of subsequent LCAP sessions.

Significant elevation of IgG anti-WRN (RecQ3 RNA/DNA helicase) antibody in systemic sclerosis.

Werner syndrome, caused by the homologous mutation of RecQ3 RNA/DNA helicase (WRN), is often misdiagnosed as systemic sclerosis (SSc) because of apparent similar skin changes and its relatively high frequency in Japan. The present study was undertaken to determine whether anti-WRN antibodies assayed by specific enzyme-linked immunosorbent assay occur in 41 SSc patients (30 diffuse and 11 limited types) and, if so, to determine any clinical association, such as skin sclerosis. Serum level of IgG anti-WRN antibody in SSc was significantly higher than that from 30 age- and sex-matched normal volunteers (P < 0.001). The serum level of IgG anti-WRN antibody in diffuse type SSc was significantly higher than the limited type (P < 0.05). A significant correlation was observed between serum levels of IgG anti-topoisomerase I antibody and IgG anti-WRN antibody in the same samples from SSc (P < 0.05). Moreover, in 119 normal healthy individuals aged from 0 to 99 years, a statistically significant correlation (P < 0.001) existed between serum level of IgG anti-WRN antibody and advancing age. A significantly higher level of IgG autoantibody specific for WRN detected in diffuse than in limited type SSc and normal may contribute to the pathogenesis of skin sclerosis in SSc.

Detection of autoantibody against carbonic anhydrase II in various liver diseases by enzyme-linked immunosorbent assay using appropriate conditions.

BACKGROUND: Immunoglobulin G autoantibody against carbonic anhydrase (CA) II has been detected in the sera of patients with a variety of autoimmune diseases. Antibody against CAII has also been described as a serological marker for distinguishing between cases of autoimmune cholangitis (AIC) and those of primary biliary cirrhosis (PBC). However, the optimal antibody measurement conditions (enzyme-linked immunosorbent assay: ELISA) have not yet been established. Moreover, we also found that a small amount of an IgG-like material exists in purchased CAII reagents, which causes pseudopositive reactions. METHODS: The sera of 96 patients with liver disease were examined for the presence of anti-CAII antibody using antigen (CAII) not containing the IgG-like material as the most suitable measurement conditions. Compared with the anti-CAII antibody prevalence of 3.8% found in normal subjects, a significantly higher seroprevalence of the antibody was detected in patients with PBC (31.0%, P<0.02), autoimmune hepatitis (AIH) (50.0%, P<0.01) and chronic viral hepatitis (27.5%, P<0.01). But, in cases of PBC, no significant correlation was noted between the level of anti-CAII antibody and the presence of anti-mitochondrial antibodies (AMA). CONCLUSIONS: While CAII may be a target antigen in autoimmune diseases, the anti-CAII antibody is not likely to be a specific marker of AIC. The optimum measurement conditions for the ELISA for anti-CAII antibody would provide us with valuable information to elucidate the underlying immunological abnormalities in liver diseases.

Detection of anti-SS-A/Ro and anti-SS-B/La antibodies of IgA and IgG isotypes in saliva and sera of patients with Sjögren's syndrome.

To assess the frequency and the possibility of local production of autoantibodies against SS-A/Ro and SS-B/La in patients with primary Sjögren's syndrome (SS), serum and saliva samples were obtained from 42 patients with SS, 10 with rheumatoid arthritis without sicca syndrome, and 12 healthy volunteers. Autoantibodies were detected using enzyme-linked immunosorbent assay and immunoblotting. The frequencies of IgA anti-SS-A antibody, IgA anti-SS-B antibody, IgG anti-SS-A antibody and IgG anti-SS-B antibody in serum from SS patients were 45%, 50%, 43% and 21%, respectively. The frequencies of IgA anti-SS-A antibody, IgA anti-SS-B antibody, IgG anti-SS-A antibody and IgG anti-SS-B antibody in saliva from SS patients were 31%, 33%, 40%, and 19%, respectively. We also found secretory IgA anti-SS-A and anti-SS-B antibodies accompanying secretory components in saliva and sera in representative SS patients. Significant correlations were found between serum and salivary levels of IgA anti-SS-A antibodies, and between serum and salivary levels of IgA anti-SS-B antibodies in SS patients. Significant correlations were also found between serum and salivary levels of IgG anti-SS-A antibodies, and between serum and salivary levels of IgG anti-SS-B antibodies in SS patients. Immunoblot analysis confirmed the presence of IgA-class autoantibodies against SS-A and SS-B in saliva and serum from representative patients. The presence of IgA- and IgG-class autoantibodies against SS-A and SS-B and those accompanying secretory components in saliva from SS patients suggests the local production of these antibodies and the relationship between local and systemic antibody responses.