Clinical characteristics, patient selection and clinical outcomes of tafamidis treatment in transthyretin amyloidosis cardiomyopathy

Background

Tafamidis is a stabilizer of transthyretin, specifically designed to decrease or prevent amyloidogenesis, and improves prognosis in patients with transthyretin amyloid cardiomyopathy (ATTR-CM). However, clinical coarse, selection of appropriate patients and monitoring therapeutic effect of tafamidis remained unclear.

Purpose

The aim of this study was to clarify the patients' characteristics, clinical coarse, and clinical outcomes of tafamidis in patients with ATTR-CM and to evaluate prognostic factors and changes in clinical data over time.

Methods

We evaluated consecutive 180 patients with ATTR-CM considering tafamids treatment. A total of 107 patients had tafamidis treatment (tafamidis treatment group) and 65 patients did not treat with tafamidis (treatment naïve group). The remaining 8 patients were preclinical. Clinical data were obtained at the consideration of tafamidis treatment. We divided the following the cut-off values of high-sensitivity cardiac troponin T (hs-cTnT); >0.05 ng/mL, B-type natriuretic peptide (BNP); >250 pg/ml, and estimated glomerular filtration rate (eGFR); <45 mL/min/1.73 m2 and calculated the score by adding 1 point if increased or decreased by more than the cut-off value. We divided patients into a low score group (0–1 point) and high score group (2–3 points).

Results

All of study patients in the tafamidis treatment group were wild-type ATTR-CM. Compared to tafamidis treatment group, tafamidis naïve group were significantly older (75.6±5.3 vs. 82.8±4.6 years; p<0.01), female dominant (8% vs. 28%; p<0.01), increased BNP levels (median 209 vs 306 pg/ml; p<0.01), and lower haemoglobin levels (14.1±1.8 vs. 12.4±1.8 g/dl; p<0.01). Tafamidis treatment group was significantly favourable clinical outcomes competed to treatment naïve group (p<0.05; log rank test). According to multivariate logistic regression analysis, prior heart failure hospitalization (hazard ratio [HR]: 5.93, 95% confidence interval [CI]: 1.25–28.03, p=0.03) and high score group (HR: 1.56, 95% CI: 0.37–7.25; <0.01) were the significant poor prognostic factors in tafamids treatment group. Among tafamidis treatment group, Hs-cTnT levels were significantly decreased after 12 months tafamidis treatment (0.055 [0.037–0.082] vs. 0.044 [0.033–0.077]; p<0.01) instead of no significant differences in BNP and significant decline of eGFR levels. There were no significant changes over time in the echocardiographic parameters after 12 months, and native T1 and extracellular volume fraction obtained by cardiac magnetic resonance in a limited number of patients.

Conclusion

The prognosis of ATTR-CM patients treated with tafamidis was favorable compared to tafamidis naïve group. Patient stratification combined with biomarkers predicted favorable prognosis in patients with tafamidis treatment. Hs-cTnT may be a useful maker for evaluating the therapeutic effect by tafamidis.

Funding Acknowledgement

Type of funding sources: None.

Change in echocardiography in patients with transthyretin amyloid cardiomyopathy with tafamidis treatment

Background

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive and infiltrative disease caused by the deposition of insoluble transthyretin (TTR) amyloid fibrils in the myocardium, which leads to cardiomyopathy characterized by increased ventricular wall thickness and diastolic dysfunction. TTR amyloid fibrils are performed by dissociation of the tetrameric TTR into monomers and misfolding and misassemble into insoluble fibrils. Tafamidis stabilizes the tetramers and inhibits the TTR monomerization, leads to inhibit the formation and deposition of TTR fibril. Clinical trials suggested tafamidis could improve prognosis by slowing the progression of amyloidosis. Evaluation of serial measurement echocardiographic findings by tafamidis treatment is important, but these data has not been fully revealed.

Purpose

The aim of study was to evaluate the change of echocardiographic parameter in patients with ATTR-CM received tafamidis for 12 months. Especially in strain echocardiogram, global longitudinal strain (GLS) has reported to be associated with prognosis, and apical sparing pattern, which longitudinal strain (LS) in the basal and middle segments is more severely impaired than the apical segments, is specific finding in ATTR-CM.

Method

Echocardiographic findings before and 12 months were compared in 68 patients with ATTR-CM who started a new prescription of tafamidis and 18 tafamidis naïve patients with ATTR-CM patients who underwent echocardiography annually prior to the approval of tafamidis.

Result

Among tafamidis treatment group, echocardiographic parameters were not significant changes before and after 12 months tafamidis treatment [left ventricular ejection fraction (LVEF): 49.6±10.6% vs. LVEF: 49.9±10.7% (p=0.767), interventricular septum diameter (IVSd):16.0±2.3mm vs 15.7±2.1mm (p=0.241), left ventricular posterior wall diameter (LVPWd):16.1±2.5mm vs 16.1±2.5mm (p=0.964), GLS: −8.4±2.7% vs −8.2±2.8% (p=0.419), LS at base: −4.6±2.6% vs −4.2±2.4% (p=0.291), LS at middle: −6.9±3.6% vs −6.9±2.8% (p=0.922), LS at apical:-12.7±4.2% vs −12.4±4.4% (p=0.615). Among tafamidis naïve group, these parameters remained almost unchanged in 12 months as well, except for GLS and LS at apical. LS at apical showed a significant impairment. [LVEF: 53.8±9.2% vs 51.7±9.3% (p=0.244), IVSd: 15.5±2.3mm vs 16.0±1.8mm (p=0.321), LVPWd: 15.4±2.3mm vs 15.9±2.3mm (p=0.267), GLS: −10.4±2.4% vs −9.0±2.9% (p=0.065), LS at base: −5.0±2.7% vs −5.1±2.9% (p=0.865), LS at middle: −8.9±3.1% vs −8.5±3.5% (p=0.565), LS at apical: −15.4±4.0% vs −12.6±4.4% (p=0.02); Table 1]

Conclusion

We evaluated changes in echocardiographic findings with tafamidis treatment for 12 months. The echocardiographic parameters did not change over the course of 12 months, but the decrease in LS at apex observed in the tafamidis naïve group.Segmental LS could reflect a slight progression of cardiac amyloidosis and the short-term effects of tafamidis.

Funding Acknowledgement

Type of funding sources: None.

P26 Soluble programed cell death ligand-1 is associated with acute coronary syndrome

Background

Immune checkpoint by programmed cell death (PD)-1 and its ligand (PD-L1) play crucial role in T cell tolerance toward vascular wall antigens. PD-L1 is widely expressed on a number of cells including immune cells and vascular endothelium. It was reported that increased expression of PD-L1 in dendritic cells implicates upregulated inflammation in atherosclerotic lesions that is associated with plaque instability. Although plaque rupture in coronary atherosclerosis is an important pathogenesis of acute coronary syndrome (ACS), the association between PD-L1 and ACS is still unknown.

Purpose

We hypothesize that circulating PD-L1 might be associated with ACS, reflecting endothelial damage and coronary plaque rupture. To elucidate this hypothesis, we compared serum levels of soluble PD-L1 (sPD-L1) in stable coronary artery disease (CAD) patients with those in ACS patients.

Methods

Serum levels of sPD-L1 were measured by using commercially available ELISA kit (Human PD-L1/B7-H1 DuoSet, R&D Systems) in consecutive patients with CAD admitted to our University Hospital from February 2016 to March 2017. Patients with any malignant disease or severe inflammatory disease were excluded from this study. Serum levels of sPD-L1 and clinical backgrounds were compared between stable-CAD and ACS patients.

Results

In total, 269 patients with CAD were enrolled (28 cases [10.4 %] with ACS and 241 cases [89.6 %] with stable-CAD). PD-L1 had no correlation to C-reactive protein, cardiac troponin, and classical atherosclerotic risks such as age, body mass index, estimated glomerular filtration rate, low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol, and hemoglobin A1c. Although age, sex, history of smoking, and the prevalences of hypertension, diabetes mellitus and dyslipidemia were comparable between both groups, the level of LDL-C was significantly higher in patients with ACS compared with those with stable-CAD (94.0 [77.0–112.0] mg/dL vs. 78.5 [65.0–97.0] mg/dL, P = 0.008). Also serum level of sPD-L1 was significantly increased in patients with ACS compared with those with stable-CAD (106.1 [60.9–157.7] pg/mL vs. 64.8 [30.9–102.5] pg/mL, P = 0.003). Univariate logistic regression analysis identified that serum levels of both sPD-L1 and LDL-C were independently associated with ACS. Moreover, multivariable logistic regression analysis with factors from univariate analysis identified that serum level of sPD-L1 was significantly and independently associated with ACS (odds ratio: 1.006, 95 % confidence interval: 1.001–1.012, P = 0.03).

Conclusions

This is the first study to elucidate that the increased serum levels of sPD-L1 was associated with ACS. This study suggests that sPD-L1 could be a risk marker and therapeutic target for ACS.

P2613Clinical significance of brachial-ankle pulse wave velocity in patients with heart failure with reduced left ventricular ejection fraction

Background

Heart failure (HF) is characterized as a complex syndrome of structural and functional cardiac disorder that impair ventricular filling and/or blood ejection. Peripheral arterial disease (PAD) is accompanied by systemic inflammation and is frequently associated with other cardiovascular diseases. Although PAD and HF share cardiovascular risk and pathophysiological features, and each has been associated with increased morbidity and mortality. Pulse wave velocity (PWV) is known to be an indicator of arterial stiffness. We previously reported the prognostic significance of brachial–ankle PWV (baPWV) in patients with HF with preserved left ventricular ejection fraction. However, its association with cardiovascular outcomes in HF with reduced EF (HFrEF) and HF with mid-range EF (HFmrEF) patients remains uncertain.

Purpose

The first aim of this study was to investigate the impact of PAD on prognosis in HFrEF and HFmrEF. The second aim was to investigate the relationship between baPWV and the occurrence of cardiovascular events in patients with HFrEF and HFmrEF.

Methods

We measured ankle-brachial pressure index (ABI) and baPWV values at stable condition after optimal therapy for HF in 201 consecutive HFrEF and HFmrEF patients admitted to Kumamoto University Hospital from 2007 to 2015 who were enrolled and followed until the occurrence of cardiovascular events.

Results

The mean age of the two groups of patients was 67.5±11.8 years. The prevalence of PAD, defined as an ABI 0.9 or less, was 14% in patients. Kaplan–Meier analysis revealed that HFrEF and HFmrEF patients with PAD had a significant higher risk of total cardiovascular and HF-related events than those without PAD (P=0.03 and P=0.01, respectively). The hazard ratio (HR) between HFrEF and HFmrEF patients without PAD and those with PAD was compared after adjustment for other confounders. The probabilities of total cardiovascular and HF-related events in HFrEF and HFmrEF patients with PAD were significantly higher than those in HFrEF and HFmrEF patients without PAD (HR: 2.19; 95% CI: 1.02–4.73; P=0.04, and HR: 3.5; 95% CI: 1.27–9.66; P=0.01, respectively). Next, we divided HFrEF and HFmrEF patients without PAD into three groups according to baPWV values. In the Kaplan–Meier analysis, total cardiovascular and HF-related events in the highest baPWV group (1800 cm/s ≤ baPWV) had a significantly higher frequency than those in the mid-level baPWV group (1400 cm/s ≤ baPWV < 1800 cm/s) (P=0.007 and P=0.004, respectively) (Figure A, B). The hazard ratio (HR) between HFrEF and HFmrEF patients in the mid-level baPWV group and those with other baPWV groups was compared after adjustment for other cofounders. The probabilities of total cardiovascular and HF-related events were significantly higher in the highest baPWV group.

Conclusion

Identifying complications of PAD and measuring baPWV values in HFrEF and HFmrEF patients were useful for predicting their prognosis.

P1647Prognostic significance of circulating leukocyte subtype counts in patients with chronic heart failure

Background

Inflammation, characterized by early leukocyte recruitment, is known to be associated with vascular endothelial dysfunction and atherosclerosis. Previous studies have reported that an increased leukocyte count is a risk factor for the progression of atherosclerosis in cardiovascular diseases, and we previously reported that a high monocyte count was an independent and incremental of cardiovascular events in patients with coronary artery disease. Furthermore, previous study also reported that inflammation play a role in the pathophysiology of heart failure (HF), but few studies have evaluated the prognostic role of monocyte in patients with HF.

Purpose

To elucidate the prognostic value of monocyte in HF, we investigated the association of monocyte counts in patients with HF with their future cardiovascular events, and compared them among new categories of HF in this study.

Methods

Consecutive HF patients referred for hospitalization at Kumamoto University Hospital between 2006 and 2015 were registered. Finally, a total of 678 HF patients were enrolled in the study, and were followed prospectively until 2016 or until the occurrence of cardiovascular events. We defined high monocyte group as monocyte counts ≥360/mm3 according to previous clinical reports. We further divided HF patients into three types according to left ventricular ejection fraction (LVEF) (HF with reduced LVEF (HFrEF), HF with mid-range LVEF (HFmrEF), and HF with preserved LVEF (HFpEF)).

Results

In this study, HFrEF was 82 patients, HFmrEF was 118 patients and HFpEF was 478 patients, respectively. The average of total monocyte counts were 397±136 in HFrEF and 375±172 in HFmrEF, and 341±138 in HFpEF patients. Kaplan-Meier analysis revealed that both HFrEF and HFmrEF patients with high monocyte group (≥360 /mm3) had a significant higher risk of HF-related events (P=0.03 and P=0.02, respectively) but not of total cardiovascular events compared with those with low monocyte groups (<360/mm3) (P=0.001). By contrast, high and low monocyte groups in HFpEF patients had no significant difference in both total cardiovascular and HF-related events. Multivariate Cox hazard analysis identified a high monocyte count as an independent and significant predictor of future HF-related events in HFrEF and HFmrEF patients (hazard ratio: 3.02, 95% confidence interval: 1.20–7.59, p=0.018).

Next, by whether they had ischemic heart disease (IHD), we divided HFrEF and HFmrEF patients into two groups. Non-ischemic HF group with high monocyte counts had a significant higher risk of HF-related events compared to those with low monocyte counts (P=0.014). By contrast, there was no statistically significant difference of the occurrences of future HF-related events between in ischemic HF group with high and low monocyte counts.

Conclusion

A high monocyte count was an independent and incremental predictor of HF-related events in HFrEF and HFmrEF especially with IHD, but not in HFpEF patients.

P2611The prognostic value of serum magnesium levels in patients with heart failure with preserved left ventricular ejection fraction

Background

In heart failure (HF) patients, various factors, such as hyperactivity of the renin-angiotensin system, influence of drug therapy such as loop and thiazide diuretics, undernutrition and others, can causes hypokalemia and hypomagnesemia. Although serum magnesium (Mg) levels are closely associated with the prognosis of HF patients, the clinical significance of serum Mg levels in cardiovascular outcomes of HF with preserved ejection fraction (HFpEF) patients is not fully understood.

Purpose

We examined the relationship between serum Mg and future HF-related events in patients with HFpEF.

Methods

This study was a retrospective, single-center, observational study. We enrolled 452 consecutive HFpEF patients admitted to our university hospital between January 2007 and September 2013 and followed them for 4 years or until occurrence of HF-related events. We defined lower serum Mg as <2.0 mg/dL (=0.8 mmol/L) and higher serum Mg as ≥2.0 mg/dL based on recent clinical evidences and compared their clinical characteristics and prognosis.

Results

The mean serum Mg level was 2.12 mg/dL (median, 2.1 mg/dL; interquartile range, 2.0–2.28 mg/dL). The follow-up period was 0–50 months (median, 47.3 months) and 48 HF-related events (10.6%) were recorded. The frequency of HF-related events was significantly higher in the lower serum Mg group compared with the higher serum Mg group (n=16, 17.4% vs. n=32, 8.9%; P=0.018). There were no significant differences between groups in the use of all drugs (loop diuretics, mineralcorticoid receptor antagonists, renin-angiotensin-aldosterone system inhibitors, calcium channel blockers, β-blockers, statins and Mg preparations). The lower serum Mg group (n=92) showed significantly higher prevalence of diabetes mellitus (DM), uric acid levels and B-type natriuretic peptide (BNP)levels compared with the higher serum Mg group (n=360). Kaplan-Meier curve revealed a significantly higher probability of HF-related events in the lower serum Mg group compared with the higher serum Mg group (log-rank test, P=0.012, Figure). Multivariate Cox proportional hazard analysis revealed that the lower serum Mg group had significantly and independently higher probabilities of HF-related events compared with those in the higher serum Mg group (hazard ratio: 2.37, 95% confidence intervals: 1.27–4.41, P=0.007). We reclassified the risk of a HF-related events after adding the lower serum Mg to the prognostic factors (age, previous hospitalization for HF, DM, ln-BNP); the continuous net reclassification improvement was 29.0% (p=0.041).

Conclusion

We first demonstrated that serum Mg was significantly correlated with the occurrence of future HF-related events in HFpEF patients. Lower serum Mg is able to successfully predict future HF-related events, and management of serum Mg in HFpEF patients is thus important.

Acknowledgement/Funding

None

Effect of maintenance therapy with low-dose peginterferon for recurrent hepatitis C after living donor liver transplantation

Approximately 30% of patients who have recurrent hepatitis C after liver transplantation achieve sustained virological response (SVR) by taking a combination therapy of pegylated interferon and ribavirin. For the remaining non-SVR patients, an effective management treatment has not yet been established. In this study, efficacy of long-term peginterferon maintenance therapy for non-SVR patients was evaluated. Forty patients who had previously received the combination therapy for hepatitis C after living donor liver transplantation were classified into one of the following three groups: the SVR group (n = 11); the non-SVR-IFN group (n =17), which received low-dose peginterferon maintenance therapy for non-SVR patients; and the non-SVR-Withdrawal group (n = 12), which discontinued the interferon treatment. We then compared histological changes among these three groups after 2 or more years follow-up. Activity grade of liver histology improved or remained stable in patients in the SVR and non-SVR-IFN groups, but deteriorated in half of the patients in the non-SVR-Withdrawal group. Fibrosis improved or remained stable in 10 of 11 SVR patients and in 13 of 17 non-SVR-IFN patients, but deteriorated in all non-SVR-Withdrawal patients. Mean changes in fibrosis stage between pretreatment and final liver biopsy were -0.18, +0.06 and +2.2 in the SVR, non-SVR-IFN and non-SVR-Withdrawal groups, respectively. Fibrosis stage deteriorated to F3 or F4 significantly more rapidly in the non-SVR-Withdrawal group than in the other two groups. In conclusion, continuing long-term maintenance therapy with peginterferon prevented histological progression of hepatitis C in patients who had undergone living donor liver transplantation.

Significance of des-gamma-carboxy prothrombin in selection criteria for living donor liver transplantation for hepatocellular carcinoma

Des-gamma-carboxy prothrombin (DCP) levels reportedly correlate with histological features of hepatocellular carcinoma (HCC). We examined serum DCP as a predictor of HCC recurrence in 144 patients who underwent living donor liver transplantation. Receiver operating characteristics (ROC) analysis revealed superiority of DCP and AFP over preoperative tumor size or number for predicting recurrence. Multivariate analysis revealed tumor size >5 cm, > or =11 nodules, and DCP >400 mAU/mL as significant independent risk factors for recurrence. Incidence of microvascular invasion (62% vs. 27%, p = 0.0003) and poor differentiation (38% vs. 16%, p = 0.0087) were significantly higher for patients with DCP >400 mAU/mL than for patients with DCP < or =400 mAU/mL. In ROC analysis for patients with < or =10 nodules all < or =5 cm to predict recurrence, area under the curve was much higher for DCP than for AFP (0.84 vs. 0.69). Kyoto criteria were thus defined as < or =10 nodules all < or =5 cm, and DCP < or =400 mAU/mL. The 5-year recurrence rate for 28 patients beyond-Milan but within-Kyoto criteria was as excellent as that for 78 patients within-Milan criteria (3% vs. 7%). The preoperative DCP level offers additional information regarding histological features, and thus can greatly improve patient selection criteria when used with tumor bulk information.

Portal vein complications in pediatric living donor liver transplantation using left-side grafts

The aim of this report is to assess the rate of portal vein complications (PVCs), the success rate of treatment for PVCs and the prognosis of patients with PVCs for pediatric living donor liver transplantation (LDLT). Pre- and postoperative records of 521 pediatric LDLTs, using left-side grafts were retrospectively reviewed. The overall rate of PVC was 9%, with early PVC occurring in nine patients (1.7%) with a mortality rate of 67% and late PVC in 38 patients (7.3%). Fifteen of these patients with late PVC showed complete portal vein occlusion despite various treatments, and in six of them the graft was lost. Histological examination revealed fibrosis in portal areas in 13 patients, around the central veins associated with cholestasis in the parenchyma in 10, and hepatocyte ballooning in 12. Correction of portal vein flow or retransplantation is necessary for the rescue of patients with early PVCs. Graft loss in the long term may be high with the occurrence of liver failure or portal hypertension related causes, such as hepatopulmonary syndrome and gastrointestinal bleeding in patients with late PVCs. For the rescue of these patients, especially for patients with body weight < 6 kg, regular monitoring of portal vein flow is essential.

New protocol of immunosuppression for liver transplantation across ABO barrier: the use of Rituximab, hepatic arterial infusion, and preservation of spleen

INTRODUCTION

An ABO-incompatible (ABO-I) living donor liver transplantation (LDLT) is a challenge. Until 2000 systemic multidrug immunosuppression and splenectomy was the gold standard with poor results. Application of local administration with prostagrandin E1 (PGE1) and steroids via a portal vein (PV) catheter dramatically improved the survival from 20% to 60% but PV thrombus became a problem (35%). To solve it, an hepatic arterial (HA) catheter was used instead of a PV catheter and splenectomy was omitted. Although the PV thrombus problem was resolved, the ABO antibody titers significantly increased, and two cases of uncontrollable humoral rejection (HR) were experienced. In this study, Rituximab was introduced instead of splenectomy to decrease the antibody. We report the efficacy of prophylaxis with Rituximab for ABO-I LDLT.

METHODS

Eight patients received. Rituximab at 2 to 14 days before LDLT. During the operation, the spleen was preserved. Methylpredonisolone and PGE1 were administered via an HA catheter for 2 to 3 weeks after LDLT in addition to an immunosuppressive regimen consisting of tacrolimus and steroids. Antibody titers were measured serially.

RESULT

There was no clinical HR. Two patients died of complications unrelated to HR. The antibody titer decreased compared to patients without splenectomy/rituximab. B cells (CD19) were depleted from peripheral blood for up to 3 months. Cytomegalovirus infections were decreased compared to patients with splenectomy (P = .085).

CONCLUSION

Rituximab prophylaxis and HA infusion therapy prevented clinical HR, which may provide a breakthrough to overcome the ABO blood-type barrier in liver transplantation.

Monosegmental living donor liver transplantation

BACKGROUND

Living donor liver transplant (LDLT) program has been started from 1990 in Japan, and is still major form of liver transplantation because of the scarcity of cadaveric donor organs. In small infants, implantation of left lateral segment grafts can be a problem because of a large-for-size graft. Until November 2002, we performed 867 transplants for 828 patients (561 children and 306 adults), and 14 cases received monosegment grafts from living donors.

METHODS

Fifteen patients, median age 211 days, median weights 5.95 kg, received monosegmental LDLT. The indication for using this technique was infants with an estimated graft-to-recipient weight ratio of over 4.0%.

RESULTS

Graft and patient survival is 85.7%. There were no differences in donor operation time and blood loss between monosegmentectomy and left lateral segmentectomy. Segment III grafts were indicated in 13 cases. Two vascular complications were observed (one hepatic artery thrombosis and one portal vein thrombosis).

CONCLUSIONS

Monosegental living donor liver transplantation is a feasible option with satisfactory graft survival in small babies with liver failure.

Living donor liver transplantation in Kyoto, 2001

The living-donor liver transplant program at Kyoto University Hospital entered its 12th year in 2001. The rapid increase in adult patients that occurred with active use of right hemi-liver grafts is now reaching its plateau, limited by OR facilities and bed capacity. Graft selection is now being polarized to the left lateral section and right hemi-liver, and disease indications are becoming more similar to those for Western cadaveric programs, including a program for hepatocellular carcinoma. With the active introduction of right hemi-liver grafts, donor selection requires more multifactorial attention. Although most anatomical variants are managed surgically without significant risk, small-for-size grafts combined with high-risk patients are often a continuing problem even with the use of right hemi-liver grafts. Solutions for small-for-size syndrome with or without persistent portal hypertension and massive ascites are urgent targets of research. It will take some more time in Japan until the final establishment of a mutual compensatory system between cadaveric and living donor programs covering medical and socioeconomical aspects is achieved.

Evaluation of an office-based urine test for detecting Helicobacter pylori: a Prospective Pilot Study

BACKGROUND/AIMS

To ascertain the reliability of a newly developed office-based urine test, the RAPIRUN test, used for detection of H. pylori infection.

METHODOLOGY

Urine specimens from 142 consecutive patients undergoing gastroendoscopy (77 men, 65 women; mean 52.0 years) were tested with RAPIRUN at the same time. The total reaction time for the urine test is 20 min. None of the patients had received any H. pylori eradicating treatment. The H. pylori status was evaluated based on 5 different tests: culture, histology, biopsy urease test, 13C-urea breath test, and the RAPIRUN test. A commercial office-based kit using an immunochromatographic technique was used to examine urine samples for H. pylori antibody. H. pylori status was defined as positive when the culture was positive or if 2 of the other 3 tests (histology, biopsy urease test, and 13C-urea breath test were positive.

RESULTS

Of 93 patients with H. pylori infection, 88 were tested as positive by RAPIRUN (sensitivity 94.6%). Of 48 patients without infection, 43 were found to be negative by RAPIRUN (specificity 89.6%). One case with an invalid urine test was excluded.

CONCLUSIONS

This urine test is a rapid, inexpensive, reliable and easy-to-use tool for the diagnosis of H. pylori infection in untreated patients. It can be used for mass screening of patients' H. pylori status, particularly in children, postgastrectomy patients, uncooperative patients, and patients undergoing bismuth or proton pump inhibitor treatment.

Posttransplant lymphoproliferative disorder after liver transplantation in miniature swine

BACKGROUND

Posttransplant lymphoproliferative disorder (PTLD) is a well-known, life-threatening complication of immunosuppressive therapy, occurring in both adult and pediatric transplant recipients.

METHODS

To study the effect of major histocompatibility complex on tolerance induction to primarily vascularized liver allograft, a semi-identical miniature swine model was developed to mimic the clinical situation of parent-into-infant liver transplantation. Long-term acceptance of semi-identical liver allograft was obtained by a transient course of FK506. In a subgroup of six animals, three developed a lethal PTLD. These animals were studied by histology and immunohistochemistry and the anti-donor cellular immune response was assessed. In addition, the possible viral origin of the proliferative process was evoked.

RESULTS

Histology and immunohistochemistry revealed an abnormal B-cell proliferation in many organs of swine suffering from PTLD. Evidence of human Epstein-Barr virus, cytomegalovirus, and adenovirus was not evidenced, but a porcine virus responsible for a respiratory and reproductive syndrome (PRRS) was identified in the lymphoid tissue of these animals. In mixed lymphocyte reaction, a significant antiself immune response confirmed an infection by a virus.

CONCLUSIONS

This is the first report suggesting that PRRS virus might provoke PTLD in immunosuppressed miniature swine after orthotopic liver transplantation. Whether PTLD could be induced by injection of the PRRS virus in immunosuppressed animals, a pig model of PTLD might be developed and would represent an interesting preclinical model for testing anti-PTLD therapies.

Living donor liver transplantation for Budd-Chiari syndrome with inferior vena cava obstruction and associated antiphospholipid antibody syndrome

BACKGROUND

Recently, the antiphospholipid antibody syndrome (APLS) has been recognized as the cause of the Budd-Chiari syndrome (BCS) in adults. However, APLS-induced BCS has been seen rarely in children. The surgical strategy for BCS depends on the patency of the inferior vena cava (IVC) and on the primary disease.

METHODS

A 10-year-old boy with a diagnosis of BCS complicated with IVC obstruction caused by APLS received medical treatment and radiologic intervention for 2 years. In spite of these treatments, no relief of the symptoms could be achieved. Finally, the patient underwent living donor liver transplantation (LDLT), which required cavoplasty. He has had an uneventful course since the LDLT.

CONCLUSIONS

IVC-obstructed BCS associated with APLS seems to be a good indication for LDLT with cavoplasty. Because liver transplantation (LT) itself is not a cure for APLS, the risk of thrombosis cannot be eliminated entirely by LT. Although immunosuppression may influence antiphospholipid antibody production, long-term observation and life-long anticoagulant treatment is needed even after LT. J Pediatr Surg 36:659-662.

Simplified technique of orthotopic liver transplantation in pigs

BACKGROUND

Pig models have become common in transplantation immunological research. However, in pigs, clamping of the venous splanchnic system during orthotopic liver transplantation (OLT) is responsible for high morbidity and mortality rates; therefore, the use of venovenous bypass (VVB) is advocated. Because venous bypass can also cause specific complications, a simplified method for OLT in pigs has been developed and evaluated in terms of morbidity and mortality.

METHODS

Twenty-three OLTs were performed between pairs of inbred miniature swine. Donor and recipient pairs (weighing 20-35 kg) were selected at 3-6 months of age. In the donor, the portal vein, infrahepatic vena cava, and suprahepatic vena cava were dissected, whereas the hepatic artery was preserved in continuity with the coeliac trunk and the abdominal aorta up to the iliac bifurcation. In situ cold perfusion was then performed. The recipient was prepared simultaneously by another surgical team. After total hepatectomy and complete portal and caval clamping, the suprahepatic vena cava and portal vein were sutured; VVB was not used. After completion of both venous sutures, the liver graft was reperfused. The infrahepatic vena cava was then anastomosed and unclamped. The donor aorta conduit was implanted end-to-side to the recipient infrarenal aorta, and the biliary reconstruction consisted of a cholecystojejunostomy with a Roux-Y loop.

RESULTS

Twenty of 23 (87%) animals survived more than 1 week (7-483 days). The mean anhepatic time was 29.6+/-4.12 min. Although severe hypotension was noted during the anhepatic phase, the hemodynamic status rapidly recovered and stabilized after graft reperfusion.

CONCLUSION

Simplified technique without VVB is appropriate for successfully achieving OLT in pigs.

Effects on human and nonhuman primate immune response of a new rat anti-CD2 monoclonal antibody

BACKGROUND

Nonhuman primate models are highly clinically relevant in transplantation. The development of immunosuppressive tools or a tolerogenic regimen for primate models therefore represents an important goal of transplantation immunological research. Hence, we have developed a rat monoclonal antibody (mAb) that recognizes the CD2 molecule (LO-CD2b) on both human and nonhuman primate cells.

METHODS

The LO-CD2b mAb has been characterized by flow cytometry, E-rosetting inhibition, and Western blotting. In vitro inhibition of immune responses by LO-CD2b was assessed after both mitogenic and allogeneic stimulation in mixed lymphocyte reactions (MLR). Several LO-CD2b dose and time responses were tested. In vivo, peripheral and lymph node T-cell depletion was examined both by flow cytometry and immunohistology in 10 baboons that received intravenous injection of LO-CD2b at different doses and time courses. Xenosensitization (anti-rat) was assessed by ELISA. Renal allograft survival was followed in two baboons treated with iterative LO-CD2b injections.

RESULTS

In vitro, LO-CD2b binds a lymphocyte antigenic determinant of 52 kDa that is recognized by other well-characterized anti-CD2 mAbs (T11, Leu5b). LO-CD2b recognized natural killer CD2+ cells. Administration of 200 ng/ml LO-CD2b almost completely inhibited human and baboon mitogenic stimulation. Allogeneic baboon and human MLR were completely inhibited by the addition of LO-CD2b (at 312 ng/ml) on the day of the initiation of culture; when added after 1 or 2 days, LO-CD2b still provided a significant MLR inhibition (>50%). Incubation of LO-CD2b with baboon peripheral blood mononuclear cells produced very low cytokine levels (interferon-y, tumor necrosis factor-alpha, interleukin 2). In secondary MLR, baboon peripheral blood mononuclear cells previously incubated with LO-CD2b were unable to respond to a second allogeneic stimulation but were able to react to mitogens. In vivo, within the first hour after LO-CD2b injection (at 0.15, 0.5, and 2 mg/kg), an 85-90% peripheral depletion of CD2+ cells was observed. A partial T-cell depletion in inguinal lymph nodes was seen after 1 week. The mechanism of peripheral T-cell depletion could have been antibody-dependent cell cytotoxicity or opsonization but was complement independent. Iterative LO-CD2b injections (12 days at 0.35 mg/kg) slightly prolonged the renal allograft survival in two baboons.

CONCLUSION

LO-CD2b is a nonactivating rat anti-CD2 mAb able to strongly inhibit both mitogenic and allogeneic responses in human and nonhuman primates. In vivo, LO-CD2b provides a rapid peripheral T-cell depletion, which is reversible within days after the cessation of injections. This rat mAb represents a very important tool for in vivo experimental investigation in nonhuman primates because it similarly reacts against human T cells in vitro.

A 12-day course of FK506 allows long-term acceptance of semi-identical liver allograft in inbred miniature swine

BACKGROUND

Spontaneous tolerance to liver allograft has been reported previously in outbred pig models, but the lack of genetic background did not allow to analyze the impact of the major histocompatibility complex (MHC) on tolerance induction. A model of semi-identical liver allograft was therefore developed in inbred miniature swine in order to mimic the clinical situation of living related liver transplant (parent into infant) and to study a protocol for inducing tolerance to liver allograft.

METHODS

SLAdd (class Id/d, class IId/d) pigs received orthotopic liver allograft from heterozygous SLAcd (class Ic/d, class IIc/d) miniature swine. Eight animals did not receive immunosuppression. Fourteen SLAdd animals had a 12-day course of FK506 and were divided in two subgroups. In subgroup FK-1, six pigs received a daily intramuscular injection of FK506 at 0.1-0.4 mg/kg, in order to reach daily trough levels between 7 and 20 ng/ml; in subgroup FK-2, eight additional animals received two daily injections of FK506 at 0.05 mg/kg regardless of the daily trough levels. Graft survival, liver biological tests, histology, cellular and humoral immune responses, as well as detection of microchimerism were assessed in all groups.

RESULTS

All untreated animals rejected their allograft and died within 28.1 +/- 9.5 days. These rejector animals developed a significant anti-donor cellular and humoral immune response. No peripheral or lymphoid tissue microchimerism was detected in this group. In contrast, long-term survival was obtained in five FK-treated animals (112, 154, 406, 413, and 440 days), whereas several pigs died with a normal allograft function from either overimmunosuppression or intercurrent causes. All FK-treated pigs developed a specific anti-donor unresponsiveness in both cell mediated lymphocytotoxicity and mixed lymphocyte reaction and did not develop anti-donor alloantibodies. The study of the anti-donor immune response by mixed lymphocyte reaction, during the first postoperative week, demonstrated a specific anti-donor unresponsiveness in the peripheral blood from the first posttransplant day. Although microchimerism was detectable in the peripheral blood for several postoperative weeks (maximum 10 weeks) in FK-treated animals, donor cells or DNA were not detected during the long-term follow-up in peripheral blood or lymphoid tissues.

CONCLUSIONS

Spontaneous tolerance to semi-identical orthotopic liver allograft did not occur, whereas a 12-day course of FK506 allowed long-term graft acceptance. All FK-treated animals developed in vitro signs of specific immune unresponsiveness and transient peripheral microchimerism. The specific anti-donor cellular unresponsiveness occurred on the first postoperative day after surgery and was of long-term duration. The study of the early immunological events in this model could be of major importance regarding clinical living related liver transplantation.

Impact of the development of a liver transplant program on the treatment of biliary atresia in an institution in Japan

Kasai operation for biliary atresia (BA) and living-related liver transplantation (LRLT) for failed Kasai cases have been performed by the same team in our hospital. Outcome of the treatment for BA in the pretransplantation and posttransplantation era in our institution were compared. As the "pre" group, 35 children first underwent the Kasai operation between 1982 and 1989. The "post" group consisted of 25 patients who underwent Kasai after introduction of the LRLT program in our hospital (1990). As for the reconstruction procedure after portal dissection during Kasai, jejunal interposition hepatic portoduodenostomy for the pre group was intentionally changed to Roux-en-Y procedure for the post group to decrease the risk of duodenal leakage after LRLT. Patients who needed revision of the Kasai decreased from 57% for the pre group to 28% for the post group. There was only one re-revision in the post group compared with seven in the pre group. In the pre group, 10 patients (28.6%) died at age 6 to 16 (mean, 8.5) months before the transplantation program was initiated. In the pre group, three patients could receive a cadaveric liver transplantation in other countries, and seven had LRLT in our hospital. Ten patients (40%) in the post group had LRLT at 7 to 22 (mean, 9.3) months old, and no deaths occurred in this group. When the patients who had liver dysfunction were excluded, the percentage of the patients who could be expected to survive and accomplish growth without undergoing liver transplantation was similar for the two groups, (31.4% v 36%). The change in the reconstruction procedure and the tendency for fewer revisions of Kasai procedure were effects of the start of the liver transplant program. As a general strategy for BA, Kasai operation should be the initial procedure, followed by liver transplantation for failed Kasai. In the late-diagnosed patients, primary LRLT can be considered if the liver has already been cirrhotic. LRLT in the infantile period is a significant component of this strategy for helping all patients to survive.