Objective. We previously showed that CD13/ aminopeptidase N (EC 3.4.11.2) induces chemotactic migration of T lymphocytes by its enzymatic activity. In this study, we examined the role of CD13/ aminopeptidase N in lymphocyte involvement in rheumatoid arthritis (RA).Methods. Synovial fluids were obtained from 27 RA patients and 6 osteoarthritis (OA) patients. Synovial tissue specimens were obtained from 3 RA patients and 3 OA patients. Protease activity of aminopeptidase in synovial fluids and synovial fibroblasts was assayed fluorometrically using the specific substrate. Expression of CD13/aminopeptidase N in synovial fibroblasts was determined by flow cytometry analyses, Western blotting, and reverse transcriptase-polymerase chain reaction (RT-PCR).Results. The mean value of aminopeptidase activity in synovial fluid samples from RA patients was significantly higher than that in samples from OA patients. Increased enzymatic activity of aminopeptidase was detected on synovial fibroblasts from RA patients compared with those from OA patients. Flow cytometry showed that the expression of CD13/ aminopeptidase N on synovial fibroblasts from RA patients was higher than the expression on synovial fibroblasts from OA patients, and Western blots and RT-PCR showed that synovial fibroblasts from RA

Polymyositis (PM) and dermatomyositis (DM) are systemic inflammatory disorders affecting skeletal muscles and other organs, and are associated with high morbidity and mortality rates. In this study, we studied the prevalence, clinical features and its comparative outcome of PM/DM, comparing PM and DM. Twenty-three PM/DM patients (9 PM and 14 DM) were included in this study. The complication of interstitial pneumonia (IP) was found in 17 patients (74%). HRCT showed that non-specific interstitial pneumonia pattern was the most common in patterns of lung involvement. Twenty-one patients (91%) with PM/DM received high dose of prednisolone therapy. The percentage of patients who received methylprednisolone (mPSL) pulse and cyclosporin A was higher in DM patients than in PM patients. The percentage of patients who received mPSL pulse and cyclosporin A was higher in later (after Apr 2004) patients than in former (before Mar 2004) patients. Malignant diseases appeared in 3 patients with DM which consisted of breast cancer, epipharyngeal cancer and gastric cancer. We observed 2 deaths in DM patients during the course of therapy; one was due to IP, and the other due to miliary tuberculosis. This study showed that a poorer prognosis was observed in patients with DM when compared with those with PM, and immunosuppressive medications may be implicated at least partially in increased risk of infections and malignancies in PM/DM patients especially DM patients, indicating that patients with PM/DM may require careful monitoring during the clinical course.

To determine the significance of CD13/aminopeptidase N in collagen vascular diseases (CVD), we examined its activity and expression in sera and disease sites of patients with CVD. Significantly higher aminopeptidase activity was detected in bronchoalveolar lavage fluid from patients with interstitial lung diseases due to rheumatoid arthritis (RA), polymyositis/dermatomyositis (PM/DM), systemic sclerosis (SSc), and Sjögren's syndrome than from control subjects. Increased aminopeptidase activity and increased expression of CD13/aminopeptidase N protein were found in alveolar macrophages from CVD patients with interstitial lung diseases. Significantly higher aminopeptidase activity was detected in pleural effusions from patients with systemic lupus erythematosus (SLE) than in transudate effusions. The mean aminopeptidase activity in synovial fluids from RA patients was significantly higher than from patients with osteoarthritis. The mean value of serum aminopeptidase activity was significantly higher in patients with SLE, RA, SSc, and PM/DM than in normal subjects. This study suggests that the activity of CD13/aminopeptidase N, locally produced in the disease site, is a useful marker for CVD and that CD13/aminopeptidase N may have an important role in the pathogenesis of CVD.

Biological agents represent an important advancement in for the treatment of rheumatoid arthritis (RA), but there is a subset of patients who do not improve despite therapy. This study aimed to determine the efficacy of biological agents for RA and to identify clinical factors that are associated with their response. We studied 98 patients with RA who started an initiating biological agent which was selected from infliximab, etanercept, adalimumab and tociliximab at 4 medical institutions. Etanercept was the most frequently used biological agent followed by infliximab although there was a difference in the selection of the biological agents among medical institutions. We found that etanercept achieved the highest treatment response, remission rate and drug survival rate. A high disease activity in the baseline disease activity score-c-reactive protein (CRP) was shown to be a negative predictor of the treatment response, and high patient global assessment was significantly less likely to achieve a good response. At week 4, decreases in 28 swollen joint counts and CRP were useful as predictors for sustaining the efficacy up to week 48. These data demonstrate that assessments of the disease activity at baseline and the early treatment response may be useful in predicting the efficacy and drug survival rate of biological agents.

This is the first report of the successful treatment of advanced biliary tract cancer with gemcitabine single-agent chemotherapy in combination with Juzen-taiho-to (JTT), a Japanese traditional herbal medicine. An 84-year-old woman was referred to our hospital with general fatigue and appetite loss; she was diagnosed with advanced biliary tract cancer and accompanying colonic invasion and hepatic metastasis. The patient's response to combination chemotherapy was extremely good, and her tumors disappeared. Recent studies have confirmed the occurrence of spontaneous and induced antitumor immune responses, carried out by tumor-infiltrating lymphocytes in the tumor microenvironment. The availability, antigen presentation, and proliferation of these immune cells are increased by cytokines such as granulocyte macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-2. Recently, JTT has gained recognition as a biological response modifier that has stimulatory effects on systemic immune responses such as enhancement of cytokine expression (GM-CSF, IL-2, etc.). In addition, some chemotherapy agents, such as anthracyclines and gemcitabine, are effective boosters of the immune response through tumor-specific antigen overexpression after apoptotic tumor cell destruction. These findings suggest that JTT enhances the antitumor effects of gemcitabine, in particular its tumor-specific effects on immune response, and these drugs are a good combination for advanced biliary tract cancer therapy.