Unilateral Autoimmune Pulmonary Alveolar Proteinosis with Polymyositis-related Interstitial Lung Disease

A 61-year-old patient with cystic bronchiectasis and bronchial artery hyperplasia in the left lung was diagnosed with polymyositis-related interstitial lung disease. After nine months of immunosuppressive therapy, he developed unilateral autoimmune pulmonary alveolar proteinosis (APAP) in the right lung with respiratory failure. After bronchial artery embolization to prevent massive hemoptysis, whole-lung lavage was performed using veno-venous extracorporeal membrane oxygenation. His respiratory condition improved, and he was discharged from the hospital with supplemental oxygen. Three reported cases of APAP with polymyositis-related interstitial lung disease, including the present case, were all positive for anti-glycyl tRNA synthetase antibody and were under immunosuppressive treatment.

Incidence of acute exacerbation in patients with interstitial lung disease after COVID-19 vaccination

Acute exacerbations due to COVID-19 vaccination in patients with interstitial lung disease (ILD) have been reported, but their incidence is unknown. We investigated the incidence of exacerbations of ILD and respiratory symptoms due to the mRNA COVID-19 vaccines. A questionnaire survey was conducted on adverse reactions to the mRNA COVID-19 vaccination in 545 patients with ILD attending our hospital and retrospectively examined whether the eligible patients actually developed acute exacerbations of ILD induced by the vaccine. Of the 545 patients, 17 (3.1%) patients were aware of the exacerbation of respiratory symptoms, and four (0.7%) patients developed an acute ILD exacerbation after vaccination. Of the four patients who experienced exacerbations, two had collagen vascular disease-associated ILD, one had nonspecific interstitial pneumonia, another had unclassifiable idiopathic pneumonia, and none had idiopathic pulmonary fibrosis. Four patients were treated using steroid pulse therapy with a steroid taper, and two of the four also received intravenous cyclophosphamide pulse therapy. Tacrolimus was started in one patient with myositis-associated interstitial lung disease. Eventually, all patients exhibited improvement with immunosuppressive treatment and were discharged. COVID-19 vaccination for patients with ILD should be noted for developing acute exacerbations of ILD with low incidence, although manageable with early diagnosis and treatment.

Clinical characteristics of pulmonary hypertension in patients with pleuroparenchymal fibroelastosis

BACKGROUND

This study aimed to investigate the clinical characteristics and prognosis of patients with pleuroparenchymal fibroelastosis (PPFE) and pulmonary hypertension (PH).

METHODS

We retrospectively analyzed the data of patients who were diagnosed with PPFE and underwent transthoracic echocardiography (TTE) for the evaluation of their right heart systems within 3 months of their first visit between 2011 and 2018. Patients were divided into the PH and non-PH groups based on their peak tricuspid regurgitation velocity (TRV) on TTE (cutoff, 2.8 m/s). The clinical characteristics of PH and association between PH and survival among patients with PPFE were investigated.

RESULTS

In total, 83 patients were enrolled. Sixteen (19.3%) patients were included in the PH group. The PH group had a lower body mass index, percent predicted forced vital capacity (FVC), 6-min walk distance, and partial pressure of arterial oxygen than the non-PH group. There was no significant difference in the presence of usual interstitial pneumonia patterns in the lower lobes between the two groups. The survival period was significantly shorter in the PH group than in the non-PH group (median survival 16.3 versus 50.2 months, log-rank p < 0.001). The multivariate Cox proportional hazard model showed that male sex (hazard ratio [HR] = 4.83, p < 0.001), Krebs von den Lungen-6 (KL-6) > 550 U/mL (HR = 3.48, p = 0.005), %FVC < 50% (HR = 3.04, p = 0.028), and peak TRV > 2.8 m/s (HR = 3.26, p = 0.038) were independently associated with poor survival.

CONCLUSIONS

PH was not rare in patients with PPFE. Male sex, increased KL-6, lower FVC, and PH were independently associated with poor survival in patients with PPFE.

Exacerbation of autoimmune pulmonary alveolar proteinosis that improved with lone treatment of complicating nontuberculous mycobacterial infection: A case report

Herein, we present the case of a 63-year-old man with autoimmune pulmonary alveolar proteinosis (APAP) complicated by Mycobacterium avium complex (MAC) infection. APAP was diagnosed based on serum anti-granulocyte-macrophage colony-stimulating factor antibody, bronchoalveolar lavage fluid (BALF) findings, and transbronchial lung biopsy. Nodular shadows with cavities were visible on chest CT images, and Mycobacterium intracellulare was identified by BALF culture. Rifampicin, ethambutol, and clarithromycin were administered, and 4 months later, the nodular shadows of MAC had disappeared, and APAP was remarkably improved. Thus, in cases of APAP exacerbation complicated with infections, such as MAC, control of the infections may improve APAP.

Risk factors for acute exacerbation following bronchoalveolar lavage in patients with suspected idiopathic pulmonary fibrosis: A retrospective cohort study

INTRODUCTION

Bronchoalveolar lavage (BAL) is useful for diagnosing diffuse lung disease and excluding other conditions. However, acute exacerbations (AEs) are recognized as important complications of BAL in patients with idiopathic pulmonary fibrosis (IPF). This study aimed to identify risk factors for BAL-induced AEs in patients with IPF.

MATERIAL AND METHODS

We retrospectively analyzed the data of 155 patients with suspected IPF who had undergone BAL between January 2013 and December 2018. BAL-related AE was defined as the development of AE within 30 days after the procedure. We compared clinical features and parameters between patients with AE (AE group) and without AE (non-AE group). We also reviewed the relevant reported literature.

RESULTS

Among the 155 patients, 5 (3.2%) developed AE within 30 days after BAL. The average duration from BAL to AE onset was 7.8 days (2-16 days). Results from the univariate analysis revealed PaO2 < 75 mm Hg (p = 0.036), neutrophil content in BAL ≥ 7% (p = 0.0061), %DLCO < 50% (p = 0.019), Gender-Age-Physiology (GAP) stage III (p = 0.034), and BAL recovery rates < 30% (p < 0.001) as significant risk factors for post-BAL AE. All five patients who developed AE recovered and were discharged.

CONCLUSIONS

Disease severity, high neutrophil levels in BAL, and poor BAL recovery rates may be risk factors for BAL-induced AEs.

Prognostic value of lymphocyte counts in bronchoalveolar lavage fluid in patients with acute respiratory failure: a retrospective cohort study

Background

Cellular patterns in bronchoalveolar lavage fluid (BALF) are used to distinguish or rule out particular diseases in patients with acute respiratory failure (ARF). However, whether BALF cellular patterns can predict mortality or not is unknown. We test the hypothesis that BALF cellular patterns have predictive value for mortality in patients with ARF.

Methods

This was a retrospective single-center observational study conducted in a Japanese University Hospital. Consecutive patients (n = 78) with both pulmonary infiltrates and ARF who were examined by bronchoalveolar lavage (BAL) between April 2015 and May 2018 with at least 1 year of follow-up were analyzed. Primary analysis was receiver operating characteristic curve—area under the curve (ROC-AUC) analysis for 1-year mortality.

Results

Among the final sample size of 78 patients, survivors (n = 56) had significantly increased lymphocyte and eosinophil counts and decreased neutrophil counts in BALF compared with non-survivors (n = 22). Among the fractions, lymphocyte count was the most significantly different (30 [12-50] vs. 7.0 [2.9-13]%, P <0.0001). In the ROC curve analysis of the association of BALF lymphocytes with 1-year mortality, the AUC was 0.787 (P <0.0001, cut-off value [Youden index] 19.0%). Furthermore, ≥20% BALF lymphocytes were significantly associated with increased survival with adjustment for baseline imbalances (1-year adjusted hazard ratio, 0.0929; 95% confidence interval, 0.0147–0.323, P <0.0001; 90-day P =0.0012). Increased survival was significantly associated with ≥20% BALF lymphocytes in both interstitial lung disease (ILD) and non-ILD subgroups (P =0.0052 and P =0.0033, respectively). In secondary outcome analysis, patients with ≥20% BALF lymphocytes had significantly increased ventilator-free days, which represents less respiratory dysfunction than those with <20% BALF lymphocytes.

Conclusions

In the patients with ARF, ≥20% lymphocytes in BALF was associated with significantly less ventilatory support, lower mortality at both 90-day and 1-year follow-ups.

The Gender-Age-Physiology system as a prognostic model in patients with idiopathic pulmonary fibrosis treated with nintedanib: a longitudinal cohort study

INTRODUCTION

The Gender-Age-Physiology (GAP) system is a tool for predicting prognosis in patients with idiopathic pulmonary fibrosis (IPF). Yet, to date, the GAP system has not been evaluated in patients with IPF who received nintedanib.

MATERIAL AND METHODS

This single-center retrospective study included 89 patients with IPF who received Nintedanib for at least 3 months. All-cause mortality was set as the end point. Clinical parameters, including the GAP stage, were statistically analyzed for risk factors leading to mortality using the Cox proportional hazard model.

RESULTS

The median follow-up was 16.4 months (range 3.7-37.4 months), during which 23 patients died. Univariate analysis revealed that the GAP stage (hazard ratio [HR] 3.00, 95% confidence interval [CI] 1.52-5.92, p = 0.0014) and PaO2 (HR 0.95, 95% CI 0.92-0.98, p = 0.0063) were significant prognostic factors. Multivariate analysis revealed that the GAP stage was a significant prognostic factor (HR 2.26, 95% CI 1.07-4.78, p = 0.031). Log-rank analysis revealed that there were no significant differences in "Gender" (p = 0.47) and "Age" (p = 0.18) factors. However, there were significant differences in "Physiology" factors (% of forced vital capacity, p = 0.018; % of diffusing capacity of lung carbon monoxide, p < 0.001). The cumulative incidences of mortality at 1 and 2 years were as follows: GAP I: 5.1% and 6.8%; GAP II: 9.5% and 29.3%; and GAP III: 18.9% and 84.2%.

CONCLUSIONS

The GAP system is useful as a prognostic tool in patients with IPF who have been treated with nintedanib.

Feasibility and accuracy of rapid on-site evaluation of touch imprint cytology during transbronchial biopsy

Background

Rapid on-site evaluation (ROSE) of cytologic material is widely performed because it provides clinicians with instant diagnostic information. However, the utility of ROSE of touch imprint cytology (ROSE-TIC) during transbronchial biopsy (TBB) remains unclear. The aim of this study was to evaluate the feasibility and accuracy of ROSE-TIC for TBB.

Methods

A retrospective study was performed on patients who underwent diagnostic bronchoscopy combined with ROSE-TIC. The results of ROSE-TIC, diagnosed as either positive or negative for malignancy, were compared with the histological findings and final diagnosis. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated. The success rate of molecular testing on TBB specimens was also assessed.

Results

Overall, 460 patients underwent bronchoscopy with ROSE-TIC. Of these, 377 cases (82.0%) were malignant and 83 cases (18.0%) were non-malignant in the final diagnosis. Compared with the histological findings, ROSE-TIC showed sensitivity, specificity, PPV, NPV, and diagnostic accuracy values of 91.1%, 90.4%, 94.8%, 84.0%, and 90.9%, respectively. Compared with the final diagnosis, ROSE-TIC showed sensitivity, specificity, PPV, NPV, and diagnostic accuracy values of 75.3%, 91.6%, 97.6%, 45.0%, and 78.3%, respectively. Seven discordant cases (1.5%) were positive on ROSE-TIC and negative on final diagnosis. The success rates for molecular analysis from TBB samples were 96.6% for EGFR mutation, 87.3% for ALK rearrangement, 93.1% for ROS1 rearrangement, and 96.2% for PD-L1 expression.

Conclusions

The accuracy of ROSE-TIC is high. It can be useful for obtaining instant diagnosis, contributing to a high success rate of molecular analysis for targeted therapy.

Clinical characteristics and risk factors of drug-induced lung injury by ALK tyrosine kinase inhibitors: A single center retrospective analysis

BACKGROUND

If anaplastic lymphoma kinase (ALK) gene rearrangement in lung cancer is identified, ALK-tyrosine kinase inhibitors (ALK-TKIs) can be an effective treatment. However, the details of drug-induced lung injury (DILI) caused by ALK-TKI, which can be a serious side effect of ALK-TKIs, remains unclear. This study aimed to investigate the clinical features and the onset risk factors of DILI by ALK-TKIs in clinical practice.

METHODS

The clinical features of 56 consecutive patients who received crizotinib, alectinib, and/or ceritinib at our hospital from 2012 to 2018 were retrospectively examined. Among these, patients diagnosed with DILI due to ALK-TKIs were evaluated in terms of clinical features and parameters. Each clinical parameter before the administration of ALK-TKIs was compared between the DILI onset group and the non-onset group.

RESULTS

A total of seven cases were diagnosed with DILI due to ALK-TKIs; no DILI-related deaths were observed. Chest computed tomography (CT) scan findings identified six patients with the organizing pneumonia (OP) pattern and one with the hypersensitivity pneumonia pattern. The onset of DILI was significantly different in patients age ≥ 64 years and with a creatinine clearance <80 mL/minute.

CONCLUSIONS

Extra caution for DILI due to ALK-TKIs may be needed when recommending ALK-TKIs for patients over 64 years of age, or with decreased renal function. CT images of the majority of patients with DILI by ALK-TKIs show an OP pattern.

KEY POINTS

Significant findings of the study: Extra caution is needed when recommending ALK-TKIs for patients over 64 years of age or those with decreased renal function. Computed tomography images of the majority of patients with DILI by ALK-TKIs show an OP pattern.

WHAT THIS STUDY ADDS

The same or a different ALK-TKI may be considered as a treatment option after the onset of DILI, based on careful judgment.

Tolerability of nintedanib-related diarrhea in patients with idiopathic pulmonary fibrosis

BACKGROUND

Nintedanib is an important drug for the treatment of idiopathic pulmonary fibrosis (IPF). However, the drug is discontinued in some patients who present with diarrhea. In this study, we aimed to assess the drug continuation rate in patients who developed diarrhea during nintedanib therapy and to evaluate if antidiarrheal drugs or nintedanib dose reductions improved clinical tolerability and efficacy.

METHODS

Eighty-six patients with IPF were treated in our institution between December 2015 and March 2018. Among them, 50 patients who experienced nintedanib-related diarrhea were analyzed regarding tolerability and persistence rate.

RESULTS

In 50 patients who experienced nintedanib-related diarrhea, 26 (n = 11, without reduction and n = 15, with reduction) continuously received nintedanib. Meanwhile, the drug was discontinued in 24 patients (n = 13, without reduction and n = 11, with reduction). In 9 of 24 patients, the drug was discontinued due to diarrhea. The annual rate of decline in forced vital capacity and the duration of nintedanib administration were not significantly different between groups with and without dosage reduction. Moreover, 23, 13, 8, and 2 patients received 1, 2, 3, and 4 agents, respectively. Clostridium butyricum is a probiotic bacterium most commonly used as an antidiarrheal agent. In this study, it was used in 28 of 46 patients. The total durations of nintedanib administration differed significantly according to the number of antidiarrheal drugs taken: 853 ± 221 days, more than three agents; 424 ± 365 days, without an agent (p = 0.043); and 460 ± 142, one agent (p = 0.0003).

CONCLUSIONS

When diarrhea occurs within a year after using nintedanib, the dose reduction may be acceptable without affecting pulmonary function. Moreover, treatment with multiple antidiarrheals may be a practical option to maintain the use of nintedanib therapy compared with monotherapy and no therapy.

Differences in tolerability of pirfenidone between elderly and younger patients with idiopathic pulmonary fibrosis

PURPOSE

Although pirfenidone (PFD) is a key drug for the treatment of idiopathic pulmonary fibrosis (IPF), differences in tolerability between elderly and young patients remain unclear. This study aimed to investigate age-related differences in adverse drug reactions to PFD and to evaluate whether patient age influences the safety and tolerability of PFD in clinical practice.

PATIENTS AND METHOD

One hundred fifty-four patients with IPF were treated with PFD in our institution between May 2009 and April 2017; these patients were classified into 2 groups on the basis of age: ≥75 years of age (elderly patients) and <75 years of age (younger patients). In each group, the clinical course, laboratory data, radiographic findings, adverse events, and tolerability of PFD at 6 months and 1 year after administration were retrospectively analyzed.

RESULTS

Among the 120 patients examined in this study, 31 patients (26%) were ≥75 years of age. The continuation rate of PFD at 1 year in the elderly patient group was significantly lower (n=11 [35%] vs 57 [64%], p=0.007) than in the younger patient group. Regarding adverse drug reactions to PFD, the incidence of gastrointestinal disorders including anorexia (n=24 [77%] vs 40 [45%], p=0.002) and the discontinuation caused by gastrointestinal disorders (n=11 [35%] vs 13 [15%], p=0.019) were significantly higher in elderly patients than those in younger patients. However, with the exception of gastrointestinal disorders, other adverse drug reactions did not significantly differ between elderly and younger patients.

CONCLUSIONS

Compared with younger patients, elderly patients with IPF had a higher incidence of gastrointestinal disorders, along with an increased discontinuation rate of PFD. More careful management of gastrointestinal disorders may be required to ensure continuation of PFD in elderly patients.

Utility of nintedanib for severe idiopathic pulmonary fibrosis: a single-center retrospective study

Introduction

The INPULSIS-ON trial demonstrated that nintedanib reduced decline in forced vital capacity (FVC) and low pulmonary function (%FVC < 50%) of patients with idiopathic pulmonary fibrosis (IPF). However, there is no sufficient evidence in real world.

Objectives

Reveal the utility and adverse events of nintedanib for severe IPF patients.

Methods

This was a single-center retrospective study. Patients who met the eligibility criteria of the INPULSIS trial (%FVC ≥ 50%; %D_LCO [diffusing capacity of the lung carbon monoxide % predicted] ≥ 30%) were classified as Mild to Moderate Group (n = 34); patients who did not meet the criteria were classified as Severe Group (n=17).

Results

The body mass index (24.7 ± 3.4 vs 22.4 ± 3.6 kg/m²; P = 0.021) were significantly low in Severe Group. Main adverse events (diarrhea, nausea, liver disorder, and acute exacerbation) tended to be more in Severe Group than in Mild to Moderate Group; however, the difference was not significant (P = 0.76, 0.14, 0.18, and 0.67, respectively). The continuation rates over 12 months tended to be higher in Mild to Moderate Group than in Severe Group (77% vs 44%; P = 0.027). Log-rank test revealed that the prognosis was significantly better in Mild to Moderate Group than in Severe Group (P = 0.014). In the Severe Group, patients who were able to continue nintedanib for more than 3 months had significantly better prognosis compared to those who could not (P = 0.007).

Conclusion

The benefit from nintedanib was reduced in patients in Severe Group when compared to those in Mild to Moderate Group; however, the prognosis is expected to improve with control of side effects and long-term administration. It is more important to control the side effects in Severe Group.

Sarcoid Myositis with Anti-Ku Antibody Consistent with both Sarcoidosis and Polymyositis

We herein describe a case of sarcoid myositis with anti-Ku antibody positivity. Pathological findings of the muscle were compatible with sarcoidosis, but could not be completely distinguished from myositis diseases that arise from other causes. According to a physical examination, pathological findings, the detection of anti-Ku antibody and the human leukocyte antigen (HLA)-DPB1 allele, we strongly suspected that the patient developed both sarcoidosis and polymyositis. Sarcoidosis is often complicated by autoimmune diseases. This case suggests the possibility that sarcoidosis and other autoimmune diseases may have common causal genetic factors.

Trousseau's syndrome: cancer-associated thrombosis

Trousseau's syndrome (cancer-associated thrombosis) is the second leading cause of death in cancer patients, after death from cancer itself. The risk of a venous thromboembolism is 4- to 7-fold higher in patients with cancer than in those without cancer. The causes of this impaired coagulation are associated with general patient-related risk factors, and other factors that are specific to the particular cancer or treatment. It is important to assess the risk of thrombotic events in cancer patients and administer effective prophylaxis and treatment. Effective prophylaxis and treatment of venous thromboembolism reduces morbidity and mortality, and improves patients' quality of life. Low molecular weight heparin is the first-line treatment for venous thromboembolism, as an effective and safe means for prophylaxis and treatment, according to guidelines released by international scientific societies. Oral anticoagulation therapy with warfarin is preferable to no therapy. However, warfarin has low efficacy and is associated with high rates of recurrence. If low molecular weight heparin is unavailable, some guidelines recommend the use of vitamin K antagonists that have a target international normalized ratio in the range of 2-3, as acceptable alternatives. Novel oral anticoagulants that directly inhibit factor Xa or thrombin are promising for the prophylaxis of high-risk cancer patients and in the long-term treatment of venous thromboembolism. However, to date, there is insufficient evidence to support the use of these new anticoagulants.

Expression mechanism of human uterine endometrial cancer-specific fucosylated carbohydrate chains - aberrant alpha-1-]4-fucosyl-transferases in uterine endometrial cancer-derived cell-lines with type-I carbohydrate chain

Cells of uterine endometrial cancer cell line SNG-II were classified into two groups according to their reactivity with anti-uterine endometrial cancer monoclonal antibody (MSN-1), whose recognition antigen is mainly the Lewis(b) antigens; those that strongly reacted with MSN-1 (SNG-S group) and those that weakly reacted with it (SNG-W group). The SNG-S showed a higher activity of a 1-->4-fucosyltransferase activity than that of the SNG-W. The expression of Lewis(b) antigen was stronger in the SNG-S than that in the SNG-W. Therefore, the expression of uterine endometrial cancer-specific fucosylated carbohydrate could be mainly controlled by alpha-fucosyltransferase activities.

8-1A, a human monoclonal antibody that reacts with intact human chorionic gonadotropin

The incidence of choriocarcinoma has decreased over time and therapeutic results have improved about 90% complete remission in patients without extensive metastasis. However, some choriocarcinomas metastasize to other organs and show resistance to chemotherapy, having a poor prognosis despite multidisciplinary treatment. Better methods of early diagnosis for recurrence or micrometastasis, and treatment against cases with intractable gestational trophoblastic neoplasia (GTN) are needed to improve the prognosis. Human chorionic gonadotropin (hCG) is a glycoprotein hormone composed of two dissimilar subunits and a tumor marker to make a diagnosis and monitor therapeutic effect in GTN. Even when hCG levels in the serum become too low to measure with the hCG beta-CTP system which is the most sensitive assay, there are estimated to be approximately 10,000 trophoblastic cells in the body. Residual trophoblast cells may cause symptoms such as bleeding or undergo malignant transformation to choriocarcinoma. Since most monoclonal antibodies developed so far are murine, administration creates human anti-mouse antibodies, resulting in clinical failure. More recent mouse/human chimeric antibodies or humanized antibodies still possess substantial immunogenicity that makes repeated administration difficult. In the present study, KM mice that can produce completely human monoclonal antibodies were used to prepare hCG-specific human monoclonal antibody. This yielded 8-1A, a human monoclonal antibody capable of reacting with intact hCG. In the future, new diagnostic techniques and treatments for chorionic diseases may be developed using this kind of human monoclonal antibody.

Selective cytotoxicity of adriamycin immunoconjugate of monoclonal antibody MSN-1 to endometrial adenocarcinoma in vitro and in vivo

Missile therapy, which destroys cancer cells specifically, has been regarded as an effective treatment modality for carcinoma. The monoclonal antibody MSN-1 (IgM), which reacts strongly with endometrial adenocarcinomas, was combined with adriamycin (ADM) by a disulfide bond using N-succinimidyl-3-(2-pyridyldithio) propionate (SPDP) and 2-iminothiolane. Its selective cytotoxicity against SNG-II was examined in a colony formation in vitro, and on athymic mice in vivo. The results of our study suggest that the <inhibitory concentration> or IC50, of the MSN-1-ADM immunoconjugate against SNG-II to be 57 times that of ADM alone in vitro. The reductions in resected weights of target tumor cells, at the local site of the MSN-1-ADM immunoconjugate treatment, were 25% with caudal vein administration, and 38% with local administration, as compared with the untreated group, in vivo. There was no weight loss in treated mice. Our results suggest that this MSN-1-ADM immunoconjugate has potential clinical application in the treatment of endometrial adenocarcinomas.

Effect of gelonin immunoconjugate with monoclonal antibody MSN-1 to endometrial adenocarcinoma on antigen-producing tumor cells in vivo

Missile therapy, which destroys cancer cells specifically, has been advocated as an effective modality for the treatment of carcinoma. We have developed an immunoconjugate consisting of the monoclonal antibody MSN-1 (IgM), which reacts strongly with endometrial adenocarcinomas, combined with a plant hemitoxin named gelonin via a disulfide bond using N-succinimidyl-3-(2-pyridyldithio) propionate and 2-iminothiolane, and examined its selective cytotoxicity in athymic mice. The reductions in resected weights of target tumor cells, at the local site of MSN-1-gelonin immunoconjugate treatment, were 96% with local administration and 75% with caudal vein administration, as compared with the untreated group. There was no weight loss in treated mice. Our results suggest that this MSN-1-gelonin immunoconjugate has potential clinical applications in the treatment of endometrial adenocarcinomas.

Detection of APC mutations by a yeast-based protein truncation test (YPTT)

APC gene mutations play a role in the initiation step of colorectal carcinogenesis in both familial adenomatous polyposis (FAP) and non-FAP patients. Almost all of the APC mutations are nonsense or frameshift mutations, which truncate the APC protein and are thought to inactivate normal APC function. We show a novel method for detecting nonsense and frameshift APC gene mutations by using Saccharomyces cerevisiae. Polymerase chain reaction (PCR)-amplified APC fragments are cloned directly into yeast expression vectors in vivo, and the yeast expresses a hemagglutinin epitope (HA)-tagged APC peptide. When an APC fragment contains a nonsense or frameshift mutation, HA-tagged truncating APC peptide can be detected by Western blotting using an anti-HA antibody. We identified both germ-line and somatic APC mutations in patients with FAP and non-FAP colorectal tumors, respectively. This method, called the yeast-based protein truncation test (YPTT), is simple and fairly cheap, and it can be applied to any genes that are inactivated by protein truncating mutations.

Effects of gelonin immunoconjugate of monoclonal antibody MSN-1 to endometrial adenocarcinoma on antigen-producing tumor cells in vitro

Missile therapy, which destroys cancer cells specifically, has been considered to be an effective modality for treatment of carcinoma. We have developed a monoclonal antibody MSN-1 (immunoglobulin class: IgM), of which the immunogen is the endometrial adenocarcinoma cell line SNG-II, which strongly reacts with endometrial adenocarcinomas. We describe an immunoconjugate consisting of the MSN-1 and a plant hemitoxin named gelonin which has revealed to assume selective cytotoxicity against the SNG-II in a colony formation assay in vitro. The results of our study suggest that the 'inhibitory concentration' or IC50, of the MSN-1-gelonin immunoconjugate against the SNG-II was 188 fold that of gelonin alone. These results indicated that the MSN-1-gelonin immunoconjugate exhibited highly selective cytotoxicity to endometrial adenocarcinoma, which expressed an epitope against the MSN-1, and it is suggested that the MSN-1-gelonin immunoconjugate has possibility of clinical application to treatment of endometrial adenocarcinomas.

Establishment of a quantitative assay of abnormal glycolipid expression in endometrial cells, and its diagnostic value for endometrial carcinoma

We developed a new quantitative method for detecting abnormal glycolipid expression in endometrial cells using a monoclonal antibody (MSN-1) and analyzed the glycolipid antigen recognized by MSN-1 in 173 clinical endometrial cell samples (66 normal endometria, 39 endometrial hyperplasias, and 68 endometrial adenocarcinomas). The mean glycolipid antigen levels in normal endometrium, endometrial hyperplasia, and endometrial carcinoma were 0.42 +/- 1.37, 2.13 +/- 3.84, and 19.4 +/- 25.8 (mean +/- SD) units, respectively. If the cutoff rate of this assay was fixed at 1.8 units, the positivity rates for patients with normal endometrium, endometrial hyperplasia, and endometrial carcinoma were 6.1% (4/66), 28.2% (11/39), and 76.5% (52/68), respectively. In 35 endometrial carcinoma patients, endometrial smears were simultaneously performed, and there were 22 positive smears (62.9%). When the cytological diagnosis was combined with our assay, 94.3% (33/35) of the carcinomas were detected. Thus, this assay seems to be a supplementary diagnostic method for endometrial carcinoma.

Enzymatic basis for the accumulation of Lewis(b) antigen in uterine endometrial cancer

In order to clarify the mechanism of the abnormal expression of Lewis(b) antigen, which was specific for uterine endometrial cancer tissue, the activities of alpha 1-->2fucosyltransferase, alpha 1-->3fucosyltransferase, and alpha 1-->4fucosyltransferase in normal endometrial tissues and uterine endometrial cancer tissues were determined. Further, an immunocytochemical study of the expression of blood group-related carbohydrate antigens in 6 cultured cell lines derived from various gynecologic malignant tumors was performed and the alpha 1-->2fucosyltransferase, alpha 1-->3fucosyltransferase, and alpha 1-->4fucosyltransferase activities of these cell lines were determined. Compared with normal endometrium, uterine endometrial cancer tissues showed significantly higher values of alpha 1-->2fucosyltransferase, alpha 1-->3fucosyltransferase, and alpha 1-->4fucosyltransferase activities. The specifically strong expression of type I carbohydrate chains, particularly the Lewis(b) antigen, was recognized in cultured cell lines derived from uterine endometrial cancer. Compared with those cell lines derived from uterine cervical cancer and ovarian cancer, the cultured cell lines derived from uterine endometrial cancer showed higher activities of alpha 1-->2fucosyltransferase and alpha 1-->4fucosyltransferase, which are enzymes related to the synthesis of Lewis(b) antigen. The cell lines derived from uterine endometrial cancer showed specifically high values of alpha 1-->4fucosyltransferase activity. These results suggest that the alpha 1-->2fucosyltransferase and alpha 1-->4fucosyltransferase activities, especially the alpha 1-->4fucosyltransferase activity, contribute to the abnormal expression of the Lewisb antigen in uterine endometrial cancer.

[Characterization of anti human uterine endometrial cancer antibody (MSN-1) and its usefulness in clinical application]

We have produced a monoclonal antibody (MSN-1), by using our endometrial cancer-cultured cell line (SNG-II) as an immunogen. MSN-1 belongs to the IgM immunoglobulin class and mainly recognized the Lewis carbohydrate moiety. It seldom, reacted immunohistochemically with normal endometrium but with about 90% of endometrial cancer cases. So, we evaluated the effectiveness of its use in clinical application. We studied the relationship between the stage of cancer and reactivity to MSN-1, and that between the reactivity of moderately differentiated endometrial cancer to MSN-1 and a 5-year survival rate. Endometrial cancer with a poor prognosis tended to react poorly to MSN-1, suggesting the possibility that the reactivity to MSN-1 is useful as a new prognostic factor. A study of endometrial hyperplasia revealed that the reactivity to MSN-1 was high in the high risk group (individuals diagnosed as endometrial cancer later). This suggested that the analysis of the expression of the antigen recognized by MSN-1 is useful in selecting the high risk group out of patients with endometrial hyperplasia. Furthermore, we indicated that abnormal expression of the antigen recognized by MSN-1 associated with neoplasia of endometrial cells is useful in developing a new diagnostic method for example our endometrial cell enzyme immunoassay (EmC-EIA) and will be helpful in developing diagnostic approaches, such as missile therapy with a complex of MSN-1 and adriamycin for endometrial cancer.

Characteristic alteration in the concentration of IV 3NeuAc alpha-nLc4Cer in the villi of human placenta during the gestational period

A study on the ganglioside composition in the villi isolated from human placenta at various gestational periods was carried out by conventional procedures including thin-layer chromatography (TLC), TLC-immunostaining, negative ion fast-atom bombardment mass spectrometry (FABMS) and exoglycosidase treatment. The major gangliosides in the villi were II3 NeuAc-LacCer (GM3) and IV3NeuAc alpha-nLc4Cer, comprising 60-70% of the total gangliosides. The concentration of IV3NeuAc alpha-nLc4Cer per gram dry weight of tissue in the villi was found to be gradually decreased from the early to the late gestational period and the molecule with 2-hydroxy fatty acids was undetectable after 20 weeks of the gestational period. However, no significant correlation between the concentration of GM3 and the gestational periods was observed. Thus the characteristic alteration in the concentration of IV3NauAc alpha-nLc4Cer in the villi might be related to various functions of human placental villi during the gestational period.

[Development of a new supplementary diagnostic method for endometrial cancer by flow cytometry employing anti-endometrial cancer antibody, MSN-1 and MSN-3]

In cytology, it is often difficult to make a definite diagnosis of endometrial cancer. In order to devise a new supplementary method, using flow cytometry we analyzed the reactivities of endometrial cells with two monoclonal antibodies (MSN-1 and MSN-3), both of which are strongly reactive to endometrial cancer cells. Employing either or both antibodies in flow cytometry, we investigated the usefulness of this analysis for distinguishing endometrial cancer cells from normal endometrial cells. Results revealed a low positive rate for normal endometrium: 9.2% with MSN-1 and 5.0% with MSN-3. In contrast, for endometrial cancer the positive rate was high: 81.2% with MSN-1 and 43.8% with MSN-3. Combined analysis with both antibodies increased the positive rate for endometrial cancer to 93.7%. These results suggest that analysis by flow cytometry employing MSN-1 and MSN-3 may have a diagnostic value for endometrial cancer. We are also investigating the usefulness of two-color analysis using these antibodies.

Abnormal expression of blood group-related antigens in uterine endometrial cancers

The expression of A, B, and H group antigens, Lewis group antigens (Lewis(a), Lewis(b), Lewis(x), and Lewis(y)), and Lc4 and nLc4 antigens, the precursor antigens of both groups, was examined immunohistochemically with monoclonal antibodies in 9 normal endometria, 6 endometrial hyperplasias, and 31 endometrial cancers. 1) A, B and/or H antigens were detected in endometrial cancers at an incidence of 51.6%, while no distinct localization of these antigens was observed in normal endometria. H antigen, the precursor of A and B antigens, was particularly frequently detected in endometrial cancers. 2) An increased rate of expression of Lewis group antigens, particularly Lewis(b) antigen, was observed in endometrial cancers compared with its expression in normal endometria. 3) Lc4 and nLc4 antigens were detected in endometrial cancers at rates of 41.9% and 38.7%, respectively, these expressions being increased compared with those in normal endometria. 4) These results suggest that a highly abnormal expression of blood group-related antigens in endometrial cancers occurs not only at the level of A, B, and H antigens and Lewis group antigens, but also at the level of their precursor Lc4 and nLc4 antigens. 5) Lewis(a), Lewis(b), and Lc4 antigens, built on the type-1 chain, are more specific to endometrial cancers than their respective positional isomers, Lewis(x), Lewis(y), and nLc4 antigens, built on the type-2 chain.

A new CA125-like antigen (CA602) recognized by two monoclonal antibodies against a newly established ovarian clear cell carcinoma cell line (RMG-II)

A cell line designated RMG-II was established from the ascites of a patient with ovarian clear cell carcinoma. The chromosomal analysis revealed aneuploidy with a hypertetraploid modal number and 8 marker chromosomes. Radioimmunoassay and immunocytochemical staining showed that RMG-II cells produced some tumor markers such as CA125 and TPA. Two monoclonal antibodies, designated MA602-1 and MA602-6, were generated by immunization of mice with an extract prepared from the culture supernatant of RMG-II cells. The epitopes recognized by these two monoclonal antibodies were proved to differ from the CA125 epitope, but to exist on the molecule bearing CA125. We developed a double-determinant sandwich enzyme immunoassay using these two monoclonal antibodies, and the antigen defined by this assay was termed CA602. CA602 was frequently found in the sera of ovarian cancer patients; the positive rates were 92%, 38%, 60%, and 80% for serous, mucinous, clear cell, and endometrioid ovarian carcinomas, respectively, when the cut-off value was set at 60 U/ml (= mean + 3SD of healthy females). CA602 levels in serum were also high in endometriosis patients and in early pregnancy, as is the case for CA125, and the correlation coefficient between CA602 and CA125 was high (r = 0.88). Our preliminary evidence suggests that this CA602 assay system has higher sensitivity than the CA125 one.

In vitro and in vivo induction of squamous cell carcinoma antigen (SCC) in a uterine cervical cancer cell line (SKG-IIIa) with peplomycin and sodium butyrate

In order to investigate the effect of an antisquamous cell carcinoma drug, peplomycin, the new analogue of bleomycin, on the production of a squamous cell carcinoma-associated tumor marker termed "SCC" (or TA-4), we carried out in vitro and in vivo experiments using the uterine cervical epidermoid cancer cell line SKG-IIIa, together with the investigation of the effect of sodium butyrate which was reported to be one of the representative gene modulators. In vitro production of SCC was biochemically and immunocytochemically confirmed in SKG-IIIa cells. Immunocytochemistry using anti-SCC antibody revealed that the total number of SCC-positive cells increased after the treatment with peplomycin (1.6 fold) or sodium butyrate (1.5 fold). The total amount of SCC in cultured medium, intracellular SCC, and cell debris during 5 days of culturation also increased with peplomycin (1.8 fold) and sodium butyrate (1.4 fold). These data strongly suggest that SCC production of SKG-IIIa cells is stimulated by peplomycin and sodium butyrate in vitro. In vivo experiments were also performed by administering peplomycin to nude rats with heterotransplanted tumors of SKG-IIIa, and transient elevations of serum SCC level (113% to 238% of the initial values) were observed, suggesting that SCC production of cancer cells is also stimulated by peplomycin in vivo.

[Establishment and characterization of a human chorionic gonadotropin (hCG) producing cell line (RTSG) from an ovarian epithelial cancer]

A new cell line designated RTSG established in vitro from the pleural effusion of a patient with metastatic ovarian epithelial cancer has been subcultured 46 times for more than 2 years. The cells grew in a monolayered sheet, showing a tendency to pile up, with the population doubling in 48 hrs. Electron-microscopically, desmosomes were characteristically observed, suggesting the cells were of epithelial origin. Chromosomal analysis revealed aneuploidy with a tetraploid mode. The heterotransplanted tumors in nude mice were histopathologically classified as a poorly differentiated adenocarcinoma, whereas the original tumor consisted mainly of mucinous and serous cystadenocarcinoma and only partly of poorly differentiated adenocarcinoma. The cells secreted hCG (38.8 mIU/day/10(6) cells) and beta-hCG (6.1 ng/day/10(6) cells) in spent medium. Immunocytologic +-and-histochemical staining for tumor markers of the original tumor, the cultured cells and the transplanted tumors also revealed the localization of not only hCG and beta-hCG but also CA19-9 and CA-125 whose values had been elevated in the preoperative serum (hCG: 10 mIU/ml, CA19-9: 6,400 U/ml, CA-125: 225 U/ml). Results of PAS, Alcian-blue and Mucicarmine strains indicated that most of the PAS-positive substances in the cultured cells and the transplanted tumors were consistent with glycogen while the original tumor mainly contained mucin except for the lesion of poorly differentiated adenocarcinoma with glycogen. These results suggested that the cultured cells might originate from poorly differentiated adenocarcinoma cells in the original tumor.

[Biological properties of two newly established cell lines (RMUG-S, RMUG-L) from a human ovarian mucinous cystadenocarcinoma]

Two morphological different cell lines (RMUG-S and RMUG-L) have been established from a human ovarian mucinous cystadenocarcinoma. CA-125 and CEA were demonstrated in the patient's serum. PAS, Alcian blue and mucicarmine positive substances were observed in the original tumor and two cultured cells. The modal chromosomal numbers of RMUG-S and RMUG-L were stable in the hypodiploid and hyper-triploid ranges, respectively. Radioimmunoassay and immunocytochemical staining revealed that RMUG-S and RMUG-L mainly produced CA-125 and CEA, respectively. In CBA nude mouse, RMUG-S and RMUG-L cells mainly produced poorly-differentiated adenocarcinoma, but in mucinous cystadenocarcinoma was detected in part of the RMUG-L tumor.

Cancer-associated galactosyltransferase as a new tumor marker for ovarian clear cell carcinoma

Serum cancer-associated galactosyltransferase antigen (caGT) was assayed in gynecological cancer patients by means of a GT-II-reactive monoclonal antibody (MAb 3872)-based immunoassay. Thirty-six of 47 (75%) ovarian cancer patients showed a significant elevation of caGT in serum above the cutoff level of 200 milliunits/ml (mean +/- 2 SD) determined from normal controls. Particularly, serum caGT levels in eight of nine patients with ovarian clear cell carcinoma were above the cutoff value, and six of them gave more than 200 milliunits/ml. Elevation of caGT in serum from pregnant women was also detected, and the level increased during the course of gestation. Immunohistochemical study revealed that not only various ovarian carcinoma cells in vivo and in vitro, but also syncytiotrophoblast of early gestational placenta, fetal tissues such as mucus-producing cells in the lower alimentary tract, and renal tubules at the 11th week of gestation were stained with MAb 3872, thus indicating its oncofetal character. Compared with CA-125, caGT showed a lower false-positive rate (10%) in benign gynecological diseases, and there was no correlation between caGT and CA-125 values. Therefore, caGT will be a useful tumor marker for ovarian cancers, especially for clear cell carcinoma.

Human monoclonal antibody (HMST-1) against lacto-series type 1 chain and expression of the chain in uterine endometrial cancers

A human monoclonal antibody termed HMST-1 was produced by fusing lymphocytes from segments of human pelvic lymph nodes from an endometrial cancer patient with murine myeloma cells. The epitope recognized by HMST-1 was determined to be lacto-series type 1 chain-containing glycosphingolipid (Gal beta 1-3GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1Cer) by isolating the antigen from endometrial cancer cell line SNG-II and analyzing with fast atom bombardment mass spectrometry, permethylation analysis, and exoglycosidase treatment. By the immunohistochemical avidin-biotin-peroxidase complex method, no normal endometrium and benign endometrial hyperplasia were stained with HMST-1, but HMST-1 reacted with about 35% of endometrial cancer cases. These facts indicate that the rate of expression of the antigen increases along with the course of malignancy in the endometrium. By sialidase treatment of the section, the positive rate increased to 57% in endometrial cancers and to 13% in normal endometrium, indicating that the antigen was masked with sialic acid and exposed by neuraminidase treatment. Immunohistochemistry also revealed that the antibody reacted with human fetal alimentary tract epithelium and mesothelium, indicating the oncodevelopmental nature of Gal beta 1-3GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1Cer.

A monoclonal antibody (MSN-1) against a newly established uterine endometrial cancer cell line (SNG-II) and its application to immunohistochemistry and flow cytometry

To determine a phenotypic difference between normal endometrium and endometrial adenocarcinoma, a new monoclonal antibody (MSN-1) was produced by immunizing a new endometrial cancer cell line (SNG-II), which was established in 1981 from a 43-year-old Japanese woman with stage II uterine endometrial cancer. MSN-1 recognized the Lewis-b carbohydrate moiety on the cell surface glycolipid and seldom reacted immunohistochemically with normal endometrium but with about 90% of endometrial cancer cases. By application of MSN-1 to flow cytometry, the possibility of differentiating endometrial normal cells from cancer cells was demonstrated.

[Galactosyltransferase isozyme II (GT-II) as a new tumor marker for ovarian cancers--especially for clear cell carcinoma]

Serum levels of galactosyltransferase (GT) and its isozyme (GT-II), which transfers galactose from UDP-galactose to N-acetylglucosamine etc., in gynecologic malignancies, were assayed. GT activity was assayed with UDP-[3H] galactose and ovalbumin as substrate, and GT-II was assayed by selectively removing GT-II from serum by immunoabsorption with immobilized monoclonal antibody 3872, followed by assay of bound GT activity. GT was not specific for cancer, but GT-II was positive in 74% of the ovarian cancer patients, and remarkably high serum levels were observed in mesonephroid cancers, indicating its possible usefulness as a new tumor marker. Immunohistochemical staining revealed that GT-II was localized on the cell surface and in the cytoplasm, suggesting its production by tumor cells.

Monoclonal antibody-defined antigen of human uterine endometrial carcinomas is Leb

A monoclonal antibody, MSN-1, generated by immunizing a mouse with a human uterine endometrial adenocarcinoma cell line, SNG-II, was strongly and specifically reactive with neutral glycosphingolipids from cancer tissues of patients with uterine endometrial adenocarcinomas. The glycosphingolipid antigen was purified from pooled human meconia, which contained the antigen at the concentration of 1.95 mumol/g dry weight. Its structure was determined by NMR, negative ion FABMS, permethylation analysis, and TLC-immunostaining with monoclonal anti-Lc4Cer antibody, and was concluded to be the III4IV2Fuc2Lc4Cer,Leb antigen of the human Lewis blood system. On ELISA, the monoclonal antibody was found to be strongly reactive with Leb, slightly with Lea and not at all with A, B, H, or IV2FucGg4Cer. The amount of Leb in cancerous regions in the patients with the Lea-b+ blood group was significantly increased compared to that in normal regions in the same patients, and it was a newly appearing antigen in the cancerous tissue of a patient with the Lea+b- blood group.

Establishment of a human ovarian clear cell carcinoma cell line (RMG-I) and its single cell cloning--with special reference to the stem cell of the tumor

A cell line, designated RMG-I, has been established from ascites of a patient with ovarian clear cell carcinoma. RMG-I cells have grown well for more than 6 years with mirror ball formation. Chromosome analysis revealed aneuploidy with a modal number of 47 and 3 marker chromosomes. The histological characteristics of the transplanted tumor were similar to those observed in the original tumor which was composed of dark cells, clear cells, and hobnail cells. Thus, the RMG-I cell line was identified to be an ovarian clear cell carcinoma. Immunohistochemically, basic fetoprotein (BFP) and ferritin were demonstrated in the original tumor, the cultured cells, and the transplanted tumor. Furthermore, in order to clarify whether these 3 kinds of cells originate from one stem cell or not, monoclonal cell population were transplanted into nude mice, and its histological investigation revealed that 3 types of cells existed in the transplanted tumor, proving that they originate from one stem cell.

[On the clinical usefulness of a few sugar antigens and a galactosyl-transferase]

Using human cultured cell lines or lymphocytes, two kinds of murine- and one human-monoclonal antibodies were produced, respectively and their clinical usefulness were investigated, and the possibility of galactosyl-transferase as a new tumor maker was also discussed. (1) A murine monoclonal antibody MSN-1, which was raised against human endometrial cancer cell line and recognized blood type sugar chain Leb, reacted with about 85% of endometrial cancer tissues, indicating that useful clinical information may be obtained by applying MSN-1 to immunohistochemistry and flow cytometry. (2) A new assay system using two murine monoclonal antibodies MA54 and MA61, which were raised against human lung cancer cell line and reacted with mucin sugar residues, revealed 76% positive rate in ovarian cancer patients, especially 82% in mucinous cystadenocarcinoma, indicating the clinical effectiveness as a new tumor maker compensating for the drawbacks of CA-125. (3) Galactosyl-transferase isozyme GT-2 was analyzed by the assay system using a newly produced monoclonal antibody. GT-2 was positive in 74% of ovarian cancers, especially in 89% of meso-nephroid cancer, indicating that GT-2 could be a useful tumor maker in ovarian tumors. (4) Human monoclonal antibody, which recognized "type 1 sugar chain" or iso-paragloboside, reacted about one half of endometrial cancer tissues. The production of human monoclonal antibody may contribute to the cancer imaging and the missile therapy.

[Establishment and characteristics of a new human choriocarcinoma cell line and its production of tumor markers]

A human gestational uterine choriocarcinoma cell line (NJG) was established in vitro. The NJG cell line had been subcultured more than 73 times over 7 years. The cells consisted mainly of Langhans-like cells, while multinucleated cells were occasionally seen. The cells grew in a monolayered sheet, showing a tendency to pile up, with the population doubling in 80 hrs. Electron-microscopically, desmosomes were characteristically observed, which suggested that the cultured cells were of epithelial origin. Chromosomal analysis revealed aneuploidy with a hypertriploid mode and 4 marker chromosomes. Immunocyto- and-histochemical staining for tumor markers of the cultured cells and the transplanted tumors to nude mice showed close similarity. SP1 was occasionally demonstrated and PP5 was faintly stained only in the heterotransplanted tumors, although PP10 and PP12 were not demonstrable. HCG was localized not only in syncytial cells, but also in Langhans cells, and syncytial cells without hCG were also observed in the tumors. A single cell clone was also established from the original NJG cells by a limiting dilution method. The heterotransplanted tumor consisted of Langhans and syncytial cells, indicating that both cells originated from the same cell.

[Production of monoclonal antibody against a newly established human endometrial cancer cell line SNG-II]

A cell line designated SNG-II was established from the operation specimen of human endometrial adenocarcinoma, and by means of an immunization procedure using intact SNG-II cells, a monoclonal antibody (Mab) named MSN-1 which reacts immunohistochemically with endometrial cancers was obtained. The cell line grew well without interruption for over 5 years, and, SNG-II cells produced tumors of cell differentiated adenocarcinoma in nude mice. The modal chromosomal number was diploid without a marker chromosome. The production of human chorionic gonadotropin and its beta-subunit, CA-125, tissue polypeptide antigen, and placental proteins such as PP6 and PP7 in SNG-II was confirmed. MSN-1 was of IgM subclass. As the antigenic reactivity was unchanged by trypsin treatment, but lost by periodic treatment, it was suggested that the antigen corresponding to MSN-1 was a carbohydrate sequence. Immunohistochemically MSN-1 reacted with about 70% cases of endometrial adenocarcinoma, but seldom with normal endometrium. Furthermore, the staining pattern of MSN-1 was different in benign cells from that in malignant cells: only the luminal surface of the normal endometrium was positive, whereas the cytoplasma was also stained in many of adenocarcinoma cells.