Prognostic value of estimating appendicular muscle mass in heart failure using creatinine/cystatin C

Objectives

As heart failure with concomitant sarcopenia has a poor prognosis, simple methods for evaluating the appendicular skeletal muscle mass index (ASMI) are required. Recently, a model incorporating anthropometric data and the sarcopenia index, that is, the ratio of serum creatinine to cystatin C (Cre/CysC), was developed to estimate the appendicular skeletal muscle mass. We hypothesized that this model would be superior to the previous model, which uses only anthropometric data to predict the prognosis. This study aimed to compare the prognostic value of low ASMI as defined by the biomarker and anthropometric models in patients with heart failure.

Methods

Among 847 patients, we estimated ASMI using an anthropometric model consisting of age, body weight, and height in 791 patients and a biomarker model that incorporates age, body weight, hemoglobin, and Cre/CysC in 562 patients. Patients were divided into low and non-low ASMI groups according to the ASMI estimated by each model, using the cut-off proposed by the Asian Working Group for Sarcopenia. The primary outcome was all-cause mortality.

Results

Overall, 53.4% and 39.1% of patients were diagnosed with low ASMI by anthropometric and biomarker models, respectively. The agreement of the diagnosis of low ASMI between the two models was poor, with a kappa coefficient of 0.56 (95% confidence interval: 0.49–0.63). Kaplan-Meier curves showed that a low ASMI was significantly associated with all-cause death in both models. However, this association was retained after adjustment for other covariates in the biomarker model (hazard ratio: 2.60, p=0.003), but not in the anthropometric model (hazard ratio: 0.70, p=0.257).

Conclusions and implications

Among patients hospitalized with heart failure, a low ASMI estimated using the biomarker model, but not the anthropometric model, was significantly associated with all-cause mortality.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Japan Agency for Medical Research and Development

Additional clinical impact of plaque analysis for on-site CT-derived FFR in coronary CT angiography on midterm prognosis

Background

We previously reported that per-patient on-site computed tomography-fractional flow reserve (CT-FFR), which can be acquired on-site workstation using fluid structure interaction during the multiple optimal diastolic phases measured 1 to 2 cm distal to a target lesion may be feasible for risk stratification based on future cardiac events for patients who did not undergo planned revascularization. However, per-vessel CT-FFR and the additional impact of plaque analysis on CT-FFR have not been evaluated.

Purpose

The aim of this study is to assess the clinical and additional impact of novel plaque analysis using labeling method for per-vessel CT-FFR on midterm prognosis.

Methods

A total of 254 consecutive patients with 354 vessels showing 50–90% stenosis but not revascularized within 90 days from coronary CT angiography (CCTA) on 320-row CT were retrospectively analyzed and followed during a median follow up 3.6 years. Plaque characteristics by labeling method (necrotic core/total plaque volume (% necrotic core), non-calcified plaque (NCP)/vessel volume (%NCP), and total plaque/vessel volume (%total plaque) for both total vessel volume (mm3) and at minimum lumen area (MLA, mm2)), positive remodeling (PR) and CT-FFR were analyzed on per-target vessels. The endpoint was vessel oriented-composite outcome (VOCO), including cardiac death, non-fatal MI, and unplanned revascularization.

Results

The incidence of VOCO occurred in 6.8% (24/354). In the cox proportional hazard model, a multivariate analysis identified CT-FFR≤0.80 was the most associated factor with VOCO (all values <0.01 for other plaque morphologies), but %necrotic core, %NCP, %total plaque at MLA and PR were significantly independent of CT-FFR≤0.80. (%necrotic core HR; 3.43 (p<0.01 [95% confidence interval (CI) 1.42–8.29]), %NCP HR; 4.05 (p=0.03 [95% CI 1.19–13.71]), %total plaque at MLA HR; 2.82 (p=0.02 [95% CI 1.18–6.76]), and PR HR; 2.90 (p<0.01 [95% CI 1.30–6.51]), respectively.)

Conclusion

From a view point of clinical outcomes for vessels with moderate to severe stenosis but not revascularized at initial CCTA, CT-FFR demonstrated the significant impact on per-vessel analysis. Moreover, %necrotic core, %NCP and %total plaque at MLA analyzed by labeling method provided better prognostic value in addition to CT-FFR.

Funding Acknowledgement

Type of funding sources: None.

Clinical impact of novel pericoronary adipose tissue measurement on ECG-gated non-contrast chest CT scan

Background

Pericoronary adipose tissue (PCAT) quantified from coronary computed tomography angiography (CCTA) is a new predictor of CT-derived high-risk plaque (HRP) and adverse cardiac events. There has been no report investigating the method to assess PCAT from non-contrast CT so far. In this present study, we developed a brand-new method to quantify the value of PCAT from electrocardiogram (ECG)-gated non-contrast CT (NC-PCAT).

Purpose

To develop a brand-new method to quantify NC-PCAT accurately, and evaluate its prognostic value.

Methods

We retrospectively studied two independent cohorts of patients undergoing CCTA and ECG-gated non-contrast CT for clinical indication of coronary artery disease (CAD). For former cohort of consecutive 300 patients, we validated the agreement between the NC-PCAT and PCAT, and evaluated the association between NC-PCAT and the prevalence of HRP. For latter cohort of consecutive 333 patients, we dichotomized them into two groups with median NC-PCAT, and assessed the prognostic value of NC-PCAT. To quantify NC-PCAT, we placed 15x15mm region of interest at epicardial fat tissue dorsally adjacent to right coronary ostium in axial slice of ECG-gated non-contrast CT, and defined NC-PCAT as the mean CT value of each 1x1mm pixel there. PCAT was quantified from CCTA using conventional method as described in former researches. Primary endpoint was defined as major adverse cardiac events (MACE), composite of all-cause death and non-fatal myocardial infarction. HRP was defined as coronary artery plaque which has two or more following features; positive remodeling, low attenuation, spotty calcification, and napkin-ring sign.

Results

NC-PCAT was well-correlated with PCAT (r=0.68, p<0.0001). In former cohort, we found HRP in 34 (11.3%) patients. In multivariable logistic regression analysis, higher NC-PCAT (OR 1.06, 95% CI 1.03–1.10, p=0.0001), coronary artery calcium score (CACS) (OR 1.01 per 10 CACS increase, 95% CI 1.00–1.02, p=0.013), and current smoking (OR 2.58, 95% CI 1.03–6.49, p=0.044) were independent predictors of the prevalence of HRP. Among patients with CACS more than zero (n=193), NC-PCAT (OR 1.06, 95% CI 1.03–1.10, p=0.0002), current smoking (OR 3.02, 95% CI 1.17–7.82, p=0.027), and male (OR 2.81, 95% CI 1.06–7.48, p=0.028) were independent predictors of the prevalence of HRP, whereas CACS was not (p=0.15). In latter cohort, the median duration of follow-up was 2.9 years (IQR 1.9–3.9), and 16 (4.8%) cases of MACE were identified. The cumulative incidence of MACE was significantly higher in high NC-PCAT group. Multivariable cox hazard regression analysis revealed that higher NC-PCAT was an independent predictor of primary endpoint, even after adjustment for sex and age (HR 4.28, 95% CI 1.20–12.52, p=0.012).

Conclusions

There was a positive correlation between NC-PCAT and PCAT. Higher NC-PCAT is significantly associated with not only the prevalence of HRP, but also worse clinical outcome.

Funding Acknowledgement

Type of funding sources: None.

Determination of physiological cardiac myosin-binging protein levels (cMyc) in healthy populations

Background

Cardiac myosin–binding protein C (cMyC) is a cardiac-restricted protein that has more abundant, rapid release and clearance kinetics than cardiac troponin. The current ESC guideline suggests the cMyC may provide value as an alternative to cardiac troponin. The 99th percentile value is universally endorsed as the reference cut off to aid in the diagnosis of acute myocardial infarction (AMI), however, none of the report of healthy population of cMyC.

Purpose

The aim of this study was to evaluate the distribution of cMyC values in healthy subjects.

Methods

We used two cohorts in this retrospective study. 1) Healthy subjects; a total of 500 subjects (250 men and 250 women) who had annual health examinations in 2012 in the area of Kamigoto, a suburb of Nagasaki city in Southern Japan were enrolled. All participants showed none of abnormal findings including cell blood counts, chemical analysis, liver function tests, general urine tests, occult blood tests of stool, barium swallow, mammography for women, abdominal ultrasound sonography, and electrocardiogram. All blood samples were obtained in a fasting state in the morning. 2) Chest pain subjects; we collected samples from 250 subjects including 50 with non-ST elevation myocardial infarction visited admitted to a university hospital for measurement of high-sensitivity troponin T and coronary artery assessment by coronary angiography. We measured cMyC level in both cohorts by HISCL™-800 system (Sysmex corporation, Japan). The assay has a limit of detection of 0.5 ng/L and a lower limit of quantification of 1.3 ng/L.

Result

In healthy subjects, median age (IQR) was 44 (20, 82) in men and 50 (23, 91) in women. The 99th percentile of cMyC was 27.3 ng/L, which was around one-third lower than that in previous report (87 ng/L). In chest pain subjects, the concentrations of cMyC at presentation were significantly higher in those with versus without AMI (median, 66 ng/L versus 10 ng/L, P<0.001). Discriminatory power for AMI, as quantified by the area under the receiver-operating characteristic curve (AUC), was comparable for cMyC (AUC, 0.85 (95% CI 0.79–0.91) and hs-cTnT (AUC, 0.81 (95% CI 0.76–0.88)).

Conclusion

We defined the normal range of cMyC in healthy Japanese subjects. The level of cMyC at presentation provides discriminatory power comparable to hs-cTnT in the diagnosis of AMI. To determine the physiological value of a biomarker may be necessary to evaluate enough information about their health status.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Grant-in-Aid for Scientific Research

Optimal measurement location of on-site based CT-derived FFR on midterm prognosis

Background

Fractional Flow Reserve (FFR) derived from coronary computed tomography angiography (CCTA) enables anatomical and hemodynamical assessment of coronary artery disease. CT-FFR, which can be acquired on-site workstation using fluid structure interaction during the multiple optimal diastolic phase, has an incremental diagnostic value over conventional CCTA. However, few studies are focused on investigating the appropriate measurement location of CT-FFR, considering the prognosis, using CCTA as a standalone modality.

Purpose

The aim of this study is to assess the clinical impact on CT-FFR with an appropriate measurement.

Methods

A total of 370 consecutive patients who underwent CCTA in a single-heartbeat scan with a phase window of 70% to 99% of the R-R interval, showing 50–90% stenosis of at least one major epicardial vessel measuring ≥1.8 mm in diameter on CCTA were retrospectively analyzed and followed during a median follow up 2.9 years. CT-FFR values were measured at three points: 1, 2 cm distal to a target lesion (CT-FFR1cm, 2cm) and the vessel terminus (CT-FFRlowest), and a CT-FFR value ≤0.80 was considered abnormal. The endpoint was MACE, a composite of cardiac death, non-fatal MI, and unplanned revascularization.

Results

The incidence of MACE occurred in 8.4% (31/370) of the whole patients, including four cardiac deaths, ten all cause deaths, two non-fatal MI, and twenty unplanned revascularization. The Kaplan-Meier survival analysis demonstrated a significantly higher cumulative MACE rate in patients with positive CT-FFR1cm and 2cm than those with negative CT-FFR1cm and 2cm, while there was no significant difference between negative and positive in CT-FFRlowest, among patients with negative CT-FFR1cm and 2cm (Figure 1). Among 221 patients, who did not perform early revascularization within 90 days from CCTA, there was no significant difference in CT-FFRlowest in the incidence of MACE. In contrast, the risk of MACE was significantly higher in both positive CT-FFR1cm and CT-FFR2cm (Figure 2).

Conclusion

From a view point of clinical outcome for patients with moderate to severe stenosis on CCTA, a CT-FFR value when measured at 1-to-2 cm distal to a target lesion could be feasible for the deferral of unnecessary invasive coronary angiography safely. Moreover, CT-FFR1–2cm showed better risk stratification measurement rather than CT-FFRlowest, based on future adverse cardiac event.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Canon Medical Systems Corporation Kaplan-Meier 1Kaplan-Meier 2

One-year outcome of the rule-out group according to the 0-h /1-hour algorithm with suspected myocardial infarction in Asian countries

 

Background/Introduction; A rapid rule-out or rule-in protocol based on the 0-h/1-hour algorithm using high-sensitivity cardiac troponin T (hs-cTnT) is recommended by the European Society of Cardiology (ESC). Around 40–50% were stratified into “rule-out” group, and their 30-days prognosis was excellent. However, the one-year prognosis is uncertain. We aimed to better characterize these patients.

Methods

This study was a prospective, multi-center, observational study of patients with suspected non-ST elevation acute coronary syndrome (NSTE-ACS) admitted to 5 hospitals in Japan and Taiwan from 2014 November to 2018 December, respectively.

All patients underwent a clinical assessment the included medical history, physical examination, 12-lead ECG, standard blood test, chest radiography. Exclusion criteria were ST elevated myocardial infarction, chronic kidney disease (serum creatinine more than 3 mg/dL) and congestive heart failure, arrhythmia, or infection disease. The patients were divided into three groups according to the algorithm; “rule-out”, “observe” and “rule-in”. The final diagnosis was then adjudicated by 2 independent cardiologists using all available information, including coronary angiography, coronary computed tomography, stress electrocardiography and follow-up data. The presence of acute myocardial infarction (AMI) was defined according to the Fourth Universal Definition of Myocardial Infarction. After hospital discharge patients were follow after one-year b telephone or in written form. Major adverse cardiovascular events (including death myocardial infarction, coronary artery bypass grafting, percutaneous coronary intervention (PCI)) were recorded by establishing contact with the patient and the family physicians. The primary prognosis end point was all-cause mortality.

Results

Of the 1,187 patients were analyzed after exclusion. The prevalence rate of AMI was 16.1%. According to the algorithm, 42% (n=493) of patients were assigned to “rule-out” group and had no AMI nor death. The most common final adjudicated diagnoses were atypical chest pain (80%), gallstone attack (3%) and vasospastic angina pectoris (2%). All patients with unstable angina (4.7%) underwent PCI.

Conclusion(s)

Our findings suggest that the “rule-out” group patients according to ESC 0-h/1-hour algorithm provides very high safety and efficacy for the triage toward AMI.

Funding Acknowledgement

Type of funding source: None

Validation and comparison of BIOSTAT risk score and AHEAD score for patients with acute heart failure

Background/Introduction

Acute heart failure (AHF) is one of the major causes of mortality, and identifying the patients at high risk of mortality at the time of admission is crucial to improve clinical outcomes. Although some risk prediction models for patients with AHF have been proposed mainly from randomized clinical trials, the patients in such studies tend not to be similar to those in the real world. Recently, BIOSTAT risk score and AHEAD score derived from two large-scale registry dataset are proposed as useful risk stratification tools for patients with AHF. However, these scores have not been well externally validated and their prognostic prediction performance has not been directly compared.

Purpose

To validate and compare prognostication of BIOSTAT risk score and AHEAD score in AHF patients.

Methods

Patients who consecutively admitted to the cardiac intensive-care unit in our institution with a diagnosis of AHF from 2007 to 2011 were analyzed. Among them, patients with acute coronary syndrome, dialysis, malignancy were excluded. BIOSTAT risk score was calculated using 5 factors (age, blood urea nitrogen, BNP, hemoglobin, prescription of beta blockers), and AHEAD score was also calculated with 5 factors (atrial fibrillation, hemoglobin, age, creatinine, and diabetes mellitus). We also developed AHEAD + BNP model incorporating BNP into AHEAD score. Endpoint was 1-year all-cause death.

Results

Overall, 591 eligible patients were enrolled (mean age was 70±14 years old, 64.8% were male) and 96 patients (16.2%) died during the follow-up of 1-year. The median [interquartile range] of AHEAD score and BIOSTAT risk score were 2 [1–3] and 3 [2–4], respectively. The areas under the curves of receiver operating characteristic curve (AUC) were 0.66 for AHEAD, 0.68 for AHEAD + BNP, and 0.72 for BIOSTAT, respectively. The calibration plots for AHEAD, AHEAD + BNP, and BIOSTAT models showed good calibration (Hosmer-Lemeshow test: p=0.89, 0.74, and 0.74, respectively). The BIOSTAT model's AUC was significantly higher compared to AHEAD (p=0.018) and marginally statistically higher compared to AHEAD + BNP (p=0.054). However, BIOSTAT model showed statistically significant net reclassification improvement compared to both AHEAD (NRI: 0.43, p<0.001) and AHEAD + BNP (NRI: 0.43, p<0.001).

Conclusion

The BIOSTAT score comprised of five readily available clinical variables predict 1-year mortality of patients with AHF with good discrimination and calibration.

ROC curves

Funding Acknowledgement

Type of funding source: None

P2677A combination of HEART score and a 0-hour/1-hour algorithm for early and safe triage tool for patients in observe zone

Background

The European Society Cardiology guidelines recommend that a 0-hour/1-hour (0–1hr) algorithm using high sensitivity cardiac troponin T (hs-cTnT) improves the early triage of patients with suspected non-ST elevation acute coronary syndrome (NSTE-ACS). However, diagnostic uncertainty remains in the 25–30% of patients assigned to “observe” group.

Purpose

To establish a step wise risk score system using HEART score and 0-hour/1-hour algorithm to identify the low risk group from observation group.

Methods

This study was a prospective, multi-center, observational study of patients with suspected NSTE-ACS admitted to five hospitals in Japan and Taiwan from 2014 to 2018, respectively. We applied the algorithm and calculated HEART score simultaneously. Patients were divided into three groups according to the algorithm: hs-cTnT below 12 ng/L and delta 1 hour below 3 ng/L were the “rule out” group; hs-cTnT at least 52 ng/L or delta 1 hour at least 5 ng/L were in the “rule in” group; the remaining patients were classified as the “observe” group. All patients underwent a clinical assessment the included medical history, physical examination, 12-lead ECG, continuous ECG monitoring, pulse oximetry, standard blood test, chest radiography, cardiac and abdominal ultrasonography. Patients presenting with congestive heart failure, terminal kidney disease on hemodialysis state, arrhythmia, or infection disease (which causes to increase troponin level) were excluded. Thirty-day MACE was defined as acute myocardial infarction, unstable angina (UA), or death.

Results

Of the 1,332 patients enrolled, 933 patients were analyzed after exclusion. NSTE-ACS was the final diagnosis for 122 (13.1%) patients and none of death. The HEART score less than 4 points in observation groups identified as very low risk with a negative predictive value (NPV) of 98.1% (95% confidential interval (CI); 90.1%-100%) and sensitivity of 98.0% (95% CI; 89.6%-100%). There were only one patient (0.5%) with AMI. In case of the HEART score less than 5 points, it could also identify as very low risk with a NPV of 96.7% (95% CI; 90.8%-99.3%%) and sensitivity of 94.1% (95% CI; 83.8%-98.8%). There were only three patients (1.2%) with AMI.

Conclusion

A combination of HEART score and the 0-hour/1-hour algorithm strategy rapidly identified the patient in observation group of 30-day MACE including UA where nor further cardiac testing would be needed.

Acknowledgement/Funding

JSPS KAKENHI Grant Number JP18K09554

P6173Plaque characteristics on coronary CT angiography in case of discordance between fractional flow reserve (FFR) and instantaneous wave-free ratio (IFR)

Background

The usefulness of fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) evaluation has been confirmed in the determination of revascularization of coronary artery disease. When FFR≤0.8 and iFR≤0.89 were regarded as the criteria for positivity, the discordance was noted in approximately 20%, but this cause has not been well established.

Purpose

The purpose of this study was to investigate the patient background and features on coronary CT angiography (CCTA) showing the discordance between FFR≤0.8 and iFR≤0.89.

Methods

The subjects were consecutive 85 cases with 108 vessels in which stenosis of 30–90% was detected at one vessel of at least 2mm or more in the major epicardial vessels and FFR and iFR was performed within subsequent 90 days, among suspected cases of coronary arterial diseases which underwent CCTA. The factors showing the discordance between FFR and iFR (patient background, coronary artery calcification score, high risk plaque features on CCTA (positive remodeling, low attenuation plaque), plaque characteristics by a plaque analysis software using a new algorithm called labeling method (vessel volume, plaque volume, lumen volume, plaque length, maximum plaque burden, necrotic core area, fibrous area and calcium area) were evaluated using logistic regression analysis on per-patient and per-vessel basis.

Results

There were no significant both FFR and iFR positive definite factors on per-patient basis. The lumen volume/vessel volume (OR: 0.93, 95% CI: 0.88–0.98, P=0.0032) (OR: 0.90, 95% CI: 0.85–0.95, P<0.0001),minimum lumen area (MLA) (OR: 0.59, 95% CI: 0.41–0.85, P=0.0006) (OR: 0.64, 95% CI: 0.44–0.92, P=0.0047), the plaque volume/vessel volume (OR: 1.05, 95% CI: 1.01–1.10, P=0.0114) (OR: 1.09, 95% CI: 1.04–1.15, P=0.0002) and maximum plaque burden (OR: 1.08, 95% CI: 1.01–1.15, P=0.0095) (OR: 1.06, 95% CI: 1.00–1.13, P=0.0406) were significant both FFR and iFR positive definite factors on per-vessels basis. Discordance between FFR≤0.8 and iFR≤0.89 was observed in 23 vessels (21.3%) of 19 patients. In FFR positive and iFR negative group (15 vessels, 13.9%), positive remodeling (PR) (OR: 4.38, 95% CI: 1.13–17.00, P=0.0294) was only significant predictor. In FFR negative and iFR positive group, there was no significant predictors.

Conclusions

In both FFR and iFR, only lumen volume /vessel volume, MLA, plaque volume/vessel volume and plaque burden were significant positive definite factors. As for the discordance between FFR and iFR, PR is significant predictor in FFR positive and iFR negative group.

P2676Prospective validation of the 2015 ESC 0-hour/1-hour algorithm using high-sensitivity cardiac troponin T in Asian countries

Background/Introduction

Implementation of the 2015 ESC 0-hour/1-hour algorithm using high-sensitivity troponin (hs-cTn) T in Asian countries presents a challenge for clinical practice.

Purpose

We aimed to prospectively validate the 0-hour/1-hour algorithm in Asian countries.

Methods

We conducted a prospective, multi-center, international cohort already utilizing 0-hour/1-hour algorithm using hs-cTnT for evaluation of patients with suspected of non-ST elevation acute coronary syndrome (NSTE-ACS). All patients underwent a clinical assessment the included medical history, physical examination, 12-lead ECG, continuous ECG monitoring, pulse oximetry, standard blood test, chest radiography, cardiac and abdominal ultrasonography. Patients presenting with congestive heart failure, terminal kidney disease on hemodialysis state, arrhythmia, or infection disease (which cause to increase troponin level) were excluded. Patients were divided into three groups according to the algorithm: hs-cTnT below 12 ng/L and delta 1 hour below 3 ng/L were the “rule out” group; hs-cTnT at least 52 ng/L or delta 1 hour at least 5 ng/L were in the “rule in” group; the remaining patients were classified as the “observational” group. The final diagnosis was then adjudicated by 2 independent cardiologists using all available information, including coronary angiography, coronary computed tomography, stress electrocardiography and follow-up data. The presence of acute myocardial infarction (AMI) was defined according to the Fourth Universal Definition of Myocardial Infarction.

Results

Of the 1,332 patients enrolled in 2014 to 2018, 933 patients were analyzed after exclusion. AMI was the final diagnosis for 122 (13.1%) patients. The algorithm ruled out AMI in 401 patients with a negative predictive value and sensitivity of 100% (95% confidential interval [CI], 98.6%-100%) and 100% (95% CI, 94.0%-100%), respectively, in the rule-out group. None of the patients were diagnosed with AMI. Among the 211 patients classified into the rule-in group, 90 were diagnosed as having AMI. The positive predictive value and specificity were 43.1% (95% CI, 36.2%-50.2%) and 78.3% (95% CI, 74.5%-81.7%), respectively. The median length of hospital stay was 159 min (142–180) in rule out group.

Conclusion(s)

Our findings suggest that the 0-hour/1-hour algorithm using hs-cTnT provides very high safety and efficacy for the triage toward rapid rule-out to rule-in of AMI.

Acknowledgement/Funding

JSPS KAKENHI Grant Number JP18K09554

Possible role of vascular endothelial cells in immune responses in colonic mucosa examined immunocytochemically in subjects with and without ulcerative colitis

Phenotypic characteristics of vascular endothelial cells of the colonic mucosa in patients with ulcerative colitis and healthy controls were studied with immunoperoxidase staining by light and electron microscopy. The cells could be classified into two groups according to their phenotypes; one was positive for von Willebrand factor and the other had an antigen detected by a monoclonal antibody, OKM5. The endothelial cells positive for von Willebrand factor were usually in relatively large blood vessels, and OKM5-positive cells were mostly located in small capillaries along the glandular epithelium. OKM5-positive endothelial cells also expressed HLA-DR and interleukin-1 (IL-1). In patients with ulcerative colitis, OKM5-positive endothelial cells and spindle-shaped cells that might be precursors of endothelial cells were more numerous in the lamina propria than in the other subjects. Thus, OKM5-positive endothelial cells may be important as antigen-presenting cells and immunoregulatory cells in the intramucosal immune system. Furthermore, colonic epithelial cells in patients with ulcerative colitis synthesized HLA-DR and IL-1, and may have a close relation to immune responses, such as antigen processing and presentation to immunocompetent cells. It was suggested that these cells have a close relation to the pathogenesis of the impaired immune responses in situ in ulcerative colitis.

[Immunocytochemical characterization of the DNA-polymerase alpha-positive colonic mucosal epithelial cells in patients with ulcerative colitis]

Colonic mucosal epithelial cells (EpC) in patients with ulcerative colitis (UC) have been shown to express HLA-DR antigen. In the present study, we observed the characteristics of HLA-DR-positive EpC using immunoperoxidase technique. In the control group, colonic EpC expressed HLA-ABC, but not HLA-DR. Only the EpC at the base of glands revealed positive for DNA-polymerase alpha (DNA-P). On the other hand, in actively inflamed mucosa of UC, about 80% of glands strongly expressed HLA-DR. Furthermore, most of EpC in the HLA-DR-positive glands showed positive nuclear stainings for DNA-P. This indicates that these EpC are not in the resting stage. It is strongly suggested that there are close relationships between the regeneration or proliferation of the EpC and class II MHC (HLA-DR) expression on the EpC in UC.

Clinical and prognostic features of rectal sparing in ulcerative colitis

Thirty patients with ulcerative colitis who had been followed clinically for more than 5 years were studied. Patients with total or left-sided colitis were investigated to evaluate the significance of rectal sparing in the prognosis of the disease. Patients were divided into two groups, one with complete or relative sparing of the rectum and the other with homogeneous lesions ranging from the rectum to the proximal colon based on endoscopic findings. The administration of topical corticosteroids seemed to have little effect on rectal sparing. However, the relapse index was significantly higher in patients with rectal sparing. The intractability index, representing the ratio of the duration of the active stage to the investigation period, was also higher, though not significantly so, in this group. The results suggest that rectal sparing may give information about intractability or a tendency to relapse.

Dissociation between the functional activity and immunoreactive concentration of C1 esterase inhibitor in active and quiescent Crohn's disease

The plasma immunoreactive concentration and the functional activity of C1 esterase inhibitor (C1INH) were measured in 17 samples from 15 patients with Crohn's disease (CD) and 10 samples from healthy volunteers. C1INH activity was measured by the chromogen substrate method and the immunoreactive concentration by the single radial immunodiffusion method. The functional activity was 95.7 +/- 4.6% in the controls. In CD it was 60.8 +/- 7.5% in the active stage (CDAI greater than 100) and 113.4 +/- 4.9% in the quiescent stage (CDAI less than or equal to 100). There were significant differences between the controls and both the active and quiescent stages (p less than 0.05). The activity was significantly lower in the active than in the quiescent stages (p less than 0.01). However, the difference in the immunoreactive concentration of C1INH in the active and quiescent stages was not significant; it was 27.8 +/- 3.5 mg/dl in the active stage and 33.7 +/- 2.0 mg/dl in the quiescent stage. This difference in the pattern of change between the immunoreactive concentration and the functional activity of C1INH might arise from the mode of C1INH action, with stoichiometric binding to substrates, giving rise to irreversible complexes. These results showed the functional consumption of C1INH in active CD, which may be an aggravating factor in the pathogenesis of the inflammatory process in the patient.

Immunoglobulin-containing cells in the colonic mucosa of rabbits with carrageenan-induced colitis

Immunohistochemical analysis of immunocompetent cells in the colonic mucosa was performed with carrageenan-induced experimental colitis in rabbits. Colitis was induced by seven months of oral administration of lambda-degraded carrageenan following immunization with the same substances containing Freund's complete adjuvant. In the colonic mucosa with colitis, IgG- and IgM-containing cells were significantly increased in number (IgG: 540 +/- 94/mm2 in experimental group, vs. 120 +/- 54/mm2 in control, P less than .05, IgM: 55.0 +/- 19.7/mm2 in experimental group, vs. 6.7 +/- 2.4/mm2 in control, P less than .05). There was no significant increase of IgA-containing cells either in number or in proportion to the total mononuclear cells. These changes, induced by carrageenan in rabbits, had resembled those in human ulcerative colitis well. These observations suggested an impairment of the IgA-regulated local immune system and an abnormality in the differentiation process of immunoglobulin-secreting cells.

The leading cord method of colonofiberscopy

Although the colonofiberscope has undergone various modifications and improvements, the insertion principle remains unchanged; that is, pushing and rotation and the elasticity of the scope itself are inevitable. It often is difficult to maintain proper balance among these dynamic factors; imbalance prevents deep insertion. Over-elongation of the scope leads to insertion failure, particularly if there are adhesions of the sigmoid colon, overextension of the colon, or transverse colon ptosis. Our "leading cord" method is an excellent aid to colonofiberscopy. It can be inserted from the clamp hole of a conventional fiberscope and hardened to straighten the scope, thereby permitting deep insertion. With this technique the region from the rectum to the descending colon, as well as a ptosed transverse colon, can be straightened. Our clinical experience indicates that the rate of successful insertions in colonofiberscopy will be increased considerably with this complementary device.

Epithelial dysplasia of the rabbit colon induced by degraded carrageenan

Colonic mucosal lesions, characterized by crypt abscesses and mononuclear cell infiltration, which resemble human ulcerative colitis can be induced in rabbits by short-term (7 to 8 weeks) administration of carrageenan according to our method. In this study experimental epithelial dysplasia of the colon was induced by the p.o. administration of lambda-degraded carrageenan for a much longer period of time. Fifteen rabbits, sensitized i.m. with the same substance 1 week before, were subjected to 12 or 28 months of treatment with 1% carrageenan solution in drinking water. Histological examination disclosed chiefly mild inflammatory changes of the colonic mucosa in all animals and a focal but high-grade dysplasia (nonpolypoid) involving the mucosal epithelium in three of the five animals treated for 28 months. The present observations suggested that epithelial dysplasia of the colon may be caused in association with inflammation and that the pathological condition produced by us can be a useful model of carcinoma in situ possibly resulting from inflammation.