Unusual biliary myoepithelial carcinoma in liver-case report and immunohistochemical study.

Myoepithelial carcinoma is a well-known tumor of salivary gland, representing 1% of all salivary gland tumors. They have also been reported in other sites as skin/soft tissue, breast and lung. This paper reports a rare case of primary myoepithelial carcinoma in the liver, as well as discusses the findings of immunohistochemistry. The clinical manifestations, imaging characteristics, and histopathological changes of myoepithelial carcinoma in this case were described. The patient was a 33 years old female presented with a cystic tumor in the right lobe of the liver. As the liver tumor increased in size within six months, malignant neoplasm was suspected and thus anterior hepatic segmentectomy was performed. The mass composed of glandular-like structures and trabecular sheets of spindled shaped cells and epithelioid cells which were positive for myoepithelial markers. The tumor recurred within one year, in the left lobe of the liver and partial left lobe lobectomy was performed. The tumor resected showed similar histology to the primary tumor. Three months later, another recurrence was noted for which radiofrequency ablation was performed. This report presents a recurrent case of myoepithelial carcinoma in the liver and suggests the possibility of biliary origin of such tumor.

[Postoperative cholangitis of balloon-occluded transarterial chemoembolization (B-TACE) for hepatocellular carcinoma].

In 35 patients who underwent balloon-occluded transarterial chemoembolization (B-TACE) for hepatocellular carcinoma (HCC) since January 2013, 5 patients (14%) had postoperative cholangitis, 1 of whom required drainage of a liver abscess. Four of these patients(80%)were treated with cisplatin (CDDP)-epirubicin (EPI)-Lipiodol (Lp) emulsion, and 1 was treated with EPI-Lp emulsion.The balloon was located and inflated at the lobar level (C: conventional)in 3 patients (60%) and at the subsegmental or more distal level (SS: superselective) in 2 patients (40%). Chemical vascular damage was considered to cause the cholangitis.We conclude that it is necessary to determine the optimal drug for B-TACE to reduce vascular damage. Miriplatin may be useful because of its lower vascular damage compared with CDDP-Lp and EPI-Lp.

Randomized trial of peginterferon α-2a plus ribavirin versus peginterferon α-2b plus ribavirin for chronic hepatitis C in Japanese patients.

BACKGROUND: Pegylated interferon (PegIFN) plus ribavirin is the standard therapy for patients with chronic hepatitis C genotype 1. Although several randomized clinical trials have compared PegIFNα-2a with PegIFNα-2b, these 2 regimens have not been directly compared in Asian patients. We, therefore, compared the safety and antiviral efficacy of these agents in Japanese patients. METHODS: A total of 201 PegIFN-naïve, chronic hepatitis C patients were randomly assigned to once-weekly PegIFNα-2a (180 µg) or PegIFNα-2b (60-150 µg) plus ribavirin. We compared the sustained virological response (SVR) rates between the 2 regimens and analyzed their effects in relation to baseline characteristics, including single nucleotide polymorphisms (SNPs) near the interleukin-28B (IL28B) gene (rs8099917). RESULTS: PegIFNα-2a was associated with a higher SVR rate than PegIFNα-2b (65.3 vs. 51.0%, P = 0.039). PegIFNα-2a and SNPs near IL28B independently predicted SVR (odds ratio 2.36; 95% confidence interval [CI] 1.19-15.50, and odds ratio 7.31; 95% CI 3.45-4.68, respectively) in logistic regression analysis. PegIFNα-2a was more effective than PegIFNα-2b (81.8 vs. 62.7%, P = 0.014) in IL28B TT genotype patients, despite similarly low SVR rates in patients with TG or GG genotypes (36.4 vs. 35.9%). Patients weighing <60 kg, women, and patients aged >60 years had significantly higher SVR rates with PegIFNα-2a than with PegIFNα-2b (63.9, 61.3, and 67.3% vs. 43.8, 43.3,and 39.2%, respectively). CONCLUSIONS: PegIFNα-2a plus ribavirin resulted in higher SVR rates than PegIFNα-2b plus ribavirin in Japanese patients. PegIFNα-2a-based treatment should therefore be the preferred choice for women, older or low-weight patients, and those with the IL28B TT genotype.

Safety and short-term therapeutic effects of miriplatin-lipiodol suspension in transarterial chemoembolization (TACE) for hepatocellular carcinoma.

AIM: To determine the safety and usefulness of a novel anticancer drug, miriplatin, in transarterial chemoembolization (TACE) for unresectable hepatocellular carcinoma. PATIENTS AND METHODS: Patients (n=115) who underwent TACE with miriplatin-lipiodol suspension (miriplatin group), and control patients (n=131) who underwent TACE with cisplatin-lipiodol suspension (CDDP group) took part in this study. RESULTS: The overall incidence of adverse events was significantly lower in the miriplatin group. The percentage of patients attaining treatment effect 4 in both groups was not significantly different. The proportion exhibiting a >50% decrease in positive tumor markers following TACE was significantly greater in the CDDP group for alpha-fetoprotein, but not significantly different for des-gammma-carboxy prothrombin. CONCLUSION: Miriplatin-lipiodol suspension was associated with reduced intensity of adverse events and had comparable short-term therapeutic effects to cisplatin-lipiodol suspension, thereby indicating its usefulness in TACE.

Severe congestive heart failure with cardiac liver cirrhosis 10 years after orthotopic liver transplantation for familial amyloidotic polyneuropathy.

Reported herein is an autopsy case of familial amyloidotic polyneuropathy (FAP) with cardiac liver cirrhosis associated with amyloid cardiomyopathy after liver transplantation. At 47 years of age a Japanese woman with a transthyretin Val30Met mutation and sensorimotor polyneuropathy underwent liver transplantation; no postoperative deterioration related to the graft or polyneuropathy occurred. However, cardiovascular dysfunction associated with amyloid deposition gradually worsened. Pacemaker implantation and diuretics were ineffective against the heart failure; 10 years after transplantation the patient died. Autopsy revealed massive pleural and pericardial effusions and amyloid cardiomyopathy, especially in the right atrium and cardiac conduction system. Amyloid deposition was slight in all organs except the heart, but liver cirrhosis with reversed lobulation and centrilobular hemorrhagic necrosis was prominent. There was no histological evidence for chronic liver graft rejection. These findings suggest that liver transplantation effectively stopped amyloid deposition and ameliorated clinical FAP symptoms but that amyloid cardiomyopathy after liver transplantation in advanced clinical stages may lead to severe congestive heart failure and cardiac liver cirrhosis.

Aging and transthyretin-related amyloidosis: pathologic examinations in pulmonary amyloidosis.

Although aging is closely related with the onset of senile systemic amyloidosis (SSA) caused by wild-type transthyretin (TTR), the effect of aging on amyloid formation has remained unclear in familial amyloidotic polyneuropathy (FAP), caused by variant- and wild-type TTR. The aim of this study was to elucidate the effects of aging and/or other factors in FAP on amyloid formation in the lung, one of the most important target organs of amyloid deposition in SSA. Pulmonary amyloid distribution was determined using 19 autopsied lung samples from patients with FAP amyloidogenic TTR (ATTR) V30M, the most common type of FAP. Amyloid deposition was observed around the walls of the bronchi/ bronchioles, the pulmonary arteries, and the pulmonary veins, while no amyloid deposits could be found around the lymphatics. In addition, amyloid deposition in the alveolar regions was a characteristic finding in aged patients with FAP ATTR V30M (average ages of the patients with amyloid positive vs. negative: 50.55 +/- 8.75 vs. 39.75 +/- 4.17 years old, p < 0.005), similar to the finding in one SSA patient. These results suggest that aging could play an important role in the progression of pulmonary amyloid formation in FAP ATTR V30M.

Role of extracellular superoxide dismutase in patients under maintenance hemodialysis.

BACKGROUND: It has been well documented that free radical injury is involved in the progression of chronic renal failure. Extracellular superoxide dismutase (EC-SOD), localized on the endothelial cell surface, plays an important role in reducing oxidative stress especially in the vessels by binding to the endothelial cell surface via the heparin-binding domain. Although EC-SOD Arg213Gly, which cannot bind on endothelial cells, has been considered a polymorphism, the effect of EC-SOD on hemodialysis patients has not been well examined. METHODS: In 178 hemodialysis patients, the following examinations were performed. EC-SOD Arg213Gly was examined by polymerase chain reaction (PCR)-induced mutation restriction analysis (PCR-IMRA). As indexes of atherosclerosis, the annual progression in intima-media thickness (DeltaIMT), plaque score, pulse wave velocity (PWV) and plasma-oxidized low-density lipoprotein (OxLDL) values were examined. RESULTS: PCR-IMRA revealed that 20 of 178 patients possessed the mutation (11.2%), and the incidence was about twice as high as that in a previously reported Japanese population. Although there were no statistical differences in plaque score and PWV with and without EC-SOD Arg213Gly, DeltaIMT and plasma OxLDL values in patients with EC-SOD Arg213Gly were significantly higher than those in patients without the mutation. CONCLUSION: EC-SOD Arg213Gly is an accelerating factor for the progression of renal failure and atherosclerosis.

Studies on unfolded beta-microglobulin at C-terminal in dialysis-related amyloidosis.

BACKGROUND: In 1997, Stoppini et al reported that monoclonal antibody specific to the C-terminal 92-99 of beta(2)-microglobulin (beta(2)m) had been capable of inhibiting fibrillogenesis of beta(2)m in vitro. Meanwhile, recent studies have indicated that an acidifying procedure can unfold conformation of the precursor protein, leading to fibril formation of beta(2)m as well as a transthyretin. METHODS: We thus prepared monoclonal antibody specific to the C-terminal 92-99 (mAb 92-99), and investigated its reactivity in plasma ultrafiltrate and amyloid tissues from 18 hemodialysis patients with dialysis-related amyloidosis (DRA). RESULTS: beta(2)m extracted from ultrafiltrate showed no reaction for mAb 92-99, whereas acidified beta(2)m from ultrafiltrate showed a reaction for mAb 92-99. Similarly, a homogenate of carpal amyloid tissues showed a strong reaction for mAb 92-99 on immunoblotting. Immunohistochemical study showed also a distinct staining for mAb 92-99 in 7 Congophilic specimens from DRA patients. More interestingly, staining for mAb 92-99 could be found in most, though not all, non-Congophilic tissues. CONCLUSION: This study demonstrates that the monoclonal antibody specific to the C-terminal 92-99 of beta(2)m can detect the conformational intermediate in amyloidogenesis of beta(2)m ex vivo, and demonstrates that an unfolded beta(2)m at C-terminal could be found not only in Congophilic area but even in non-Congophilic area as well.

Muscular amyloid angiopathy with amyloidgenic transthyretin Ser50Ile and Tyr114Cys.

Among patients with familial amyloid polyneuropathy (FAP), those with transthyretin Val30Met mainly show distally predominant weakness and atrophy, whereas some FAP patients, including those with transthyretin Ser50Ile and Tyr114Cys, show muscle weakness and atrophy that is dominant proximally, simulating myopathy. To clarify the cause of proximally dominant muscular atrophy in patients with FAP transthyretin Ser50Ile and Tyr114Cys, we investigated the distinctive features of muscle specimens of patients with FAP, 3 of who had Val30Met, 2 Ser50Ile, and 2 Tyr114Cys transthyretin. All specimens showed transthyretin amyloid around blood vessels and perimysium, and neurogenic denervation patterns. The amount of amyloid around the vessels was much greater in patients with FAP Ser50Ile and Tyr114Cys than in Val30Met patients. Muscular amyloid angiopathy may contribute to motor nerve injury that, in turn, may lead to amyotropic changes in patients with FAP Ser50Ile and Tyr114Cys.

[New molecular marker in dialysis setting--misfolded beta 2-microglobulin].

More than 25 clinical settings in amyloidosis have been acknowledged in which a peculiar criminal protein, a precursor protein, has been identified. As of now, however, the mechanism of amyloidogenesis, by which a precursor protein is transformed irreversibly into an amyloid protein, remains to be clarified. We speculated that a study of the molecular conformation of beta 2-microglobulin (beta 2 m), a precursor protein in dialysis-related amyloidosis (DRA), might provide a typic model of amyloidogenesis in other precursor proteins. Therefore, we investigated the misfolding of beta 2 m in DRA using a specific monoclonal antibody against C-terminal peptide 92-99 of beta 2 m. Our study indicated the possibility that the monoclonal antibody specific for C-terminal 92-99 of beta 2 m can detect a pre-amyloid state in amyloidogenesis in vivo, which might take place in the extravascular space.

A different amyloid formation mechanism: de novo oculoleptomeningeal amyloid deposits after liver transplantation.

BACKGROUND: Liver transplantation has served as a treatment for patients with familial amyloidotic polyneuropathy (FAP) because variant transthyretin (TTR), the pathogenic protein of FAP, is predominantly produced by the liver. However, the effect on amyloid formation of TTR that is synthesised by the retina and the choroid plexus remains to be elucidated in FAP patients with liver transplants. OBJECTIVE: To investigate changes in ocular tissues and the central nervous system (CNS) of FAP patients after liver transplantation. DESIGN: Clinical study. SETTING: Graduate School of Medical Sciences, Kumamoto University, Japan. INTERVENTION: Transplantation of livers from cadaveric or living donors. MEASUREMENTS: Preoperative measures and postoperative (16-108 months) follow-up of clinical data, including routine ophthalmologic, neurologic, and laboratory evaluations. RESULTS: In 22 patients with FAP related to the amyloidogenic TTR (ATTR) Val30Met and 3 patients with FAP ATTR Tyr114Cys, after liver transplantation, 3 patients began to show evidence of de novo glaucoma, and 1 had vitreous opacity that was caused by the variant TTR. Another three patients showed new amyloid deposits in the pupillary margin, which could lead to glaucoma and vitreous opacity. As for changes in the CNS and levels of total protein and TTR in cerebrospinal fluid (CSF), after liver transplantation, two FAP ATTR Tyr114Cys patients exhibited de novo amyloid deposition in the leptomeninges, and total protein and TTR levels in CSF were significantly increased. CONCLUSIONS: Oculoleptomeningeal involvement in FAP was not prevented by liver transplantation because variant TTR produced by the retina and the choroid plexus forms amyloid fibrils in situ.

Inhibitory effect of α-tocopherol on methylmercury-induced oxidative steress.

OBJECTIVES: The present study investigated the involvement of oxidative stress in the degeneration of the cerebellum during methylmercury (MeHg) intoxication and the protective effect of α-tocopherol (Vit E) against MeHg toxicity. METHODS: After 5 mg/kg of MeHg was administered to Wistar rats for 12 consecutive days, the cerebellum were examined histopathologically. In addition, the same amount of MeHg was administered to 3 different groups of Wistar rats: rats with a Vit E-deficient diet, rats fed 150 mg/kg of Vit E for 20 consecutive days after initial MeHg administration, and rats with an ordinary diet. RESULTS: Positive immunoreactivity against anti-hydroxynonenal (HNE), a marker of lipid peroxidation, was observed in the cerebellum after MeHg administration. Levels of thiobarbituric acid reactive substance (TBARS), another marker of lipid peroxidation, and those of protein carbonyl, a biomarker for protein oxidation, increased after MeHg administration. In the rats with MeHg and a Vit E-deficient diet, mortality and prevalence of piloerection significantly increased, and in the rats with MeHg and Vit E, mortality, piloerection, retracted and crossed hind leg, and ataxic gait significantly decreased, compared with the rats with MeHg alone. The levels of NO(2) (-) and NO(3) (-) in the serum significantly increased in the rats with MeHg alone 14 days after the initial MeHg administration, but were significantly suppressed by Vit E administration. CONCLUSIONS: Oxidative stress, especially lipid peroxidation, may play an important role in the cerebellar degeneration process during MeHg intoxication and Vit E may play a protective role against MeHg toxicity as an effective antioxidant.

A novel tool for detecting amyloid deposits in systemic amyloidosis in vitro and in vivo.

We synthesized (trans,trans)-1-bromo-2,5-bis-(3-hydroxycarbonyl-4-hydroxy)styrylbenzene (BSB) and used this compound to detect amyloid fibrils in autopsy and biopsy samples from patients with localized amyloidosis, such as familial prion disease, and systemic amyloidosis, such as familial amyloidotic polyneuropathy, amyloid A (AA) amyloidosis, light chain (AL) amyloidosis, and dialysis-related amyloidosis. BSB showed reactions in all Congo red-positive and immunoreactive regions of the samples examined in the study, and some amyloid fibrils in the tissues could be detected more precisely with BSB than with the other methods. In the mouse model of AA amyloidosis, injected BSB reacted with amyloid in all regions in the serial sections in which Congo red staining was positive. A highly sensitive 27-MHz quartz crystal microbalance analysis revealed that BSB showed a significant affinity for amyloid fibrils purified from familial amyloidotic polyneuropathy and dialysis-related amyloidosis samples and suppressed formation of transthyretin amyloid in vitro. These results suggest that BSB may become a valuable tool for detection of amyloid deposits in amyloidosis and of the mechanism of amyloid formation.

Circulating level of alpha2-macroglobulin-beta2-microglobulin complex in hemodialysis patients.

BACKGROUND: The presence of alpha2-macroglobulin (alpha2M) in amyloid tissue from patients with dialysis-related amyloidosis (DRA) was demonstrated by Argilés et al in 1989. Thereafter, the formation of the complex of beta2-microglobulin (beta2m) with alpha2m was confirmed directly by in vitro study. In Alzheimer's disease, complex formation of amyloid beta-peptide and alpha2M is considered to play an important role in the pathogenesis by modifying the degradation processes of amyloid protein. Thus, we hypothesized that the alpha2M-beta2m complex is an important factor in the pathogenesis of DRA as well. Here, we measured the circulating levels of alpha2M-beta2m complex in the maintenance hemodialysis patients and discussed about its clinical significance in DRA. METHODS: One hundred and thirty-seven hemodialysis patients and 11 prehemodialysis chronic renal failure (CRF) patients were included in this study. The affinity of purified alpha2M for beta2m was confirmed by a highly sensitive 27 MHz quartz crystal microbalance (QCM). The presence of circulating alpha2M-beta2m complex was analyzed by immunoblotting analysis. Furthermore, the serum levels of alpha2M-beta2m complex were measured by sandwich enzyme immunoassay. RESULTS: QCM analysis revealed the high affinity of alpha2M for beta2m. The presence of circulating alpha2M-beta2m complex was detected in two out of a total 11 prehemodialysis CRF patients and in 95 out of the total of 137 hemodialysis patients. None of the healthy subjects, however, were observed to present with any alpha2M-beta2m complex. Serum levels of the alpha2M-beta2m complex were correlated to the duration of hemodialysis (P= 0.043). Serum levels of the alpha2M-beta2m complex were significantly higher in patients with high DRA score than in patients with negative DRA score (P= 0.018). Moreover, serum levels of the alpha2M-beta2m complex showed significantly lower in the hemodiafiltration patients compared to the hemodialysis patients (P= 0.002) and showed a strong correlation with DRA score in hemodialysis patients excluding 11 hemodiafiltration patients (P= 0.0004). CONCLUSION: This study is the first to demonstrate the presence of circulating alpha2M-beta2m complex in hemodialysis patients. Furthermore, we observed the correlation between serum levels of alpha2M-beta2m complex and clinical characteristics of DRA. Thus we concluded that a formation of an alpha2M-beta2m complex may be implicated in DRA.

Role of VLDL/chylomicron in amyloid formation in familial amyloidotic polyneuropathy.

We examined the affinity of transthyretin (TTR) for lipoproteins and the effect of lipoproteins on TTR-related amyloidogenesis using serum samples from healthy volunteers and patients with familial amyloidotic polyneuropathy (FAP) ATTRVal30Met. In both volunteers and patients, TTR levels were highest in the VLDL fraction containing chylomicrons (VLDL/CM) and next highest in the HDL fraction. Levels were lowest in the LDL fraction. Mass spectrometric analyses of TTR spectra revealed significant TTR association with VLDL/CM and the levels of variant TTR were decreased in the FAP patients. Examination of the affinity of wild-type and variant TTRs for lipoprotein via a quartz crystal microbalance (QCM) revealed the highest affinity of both proteins for VLDL/CM. In in vitro amyloid formation test measured with thioflavin T and electron microscopy, in the presence of VLDL/CM, amyloid formation of TTR was enhanced more than in the presence LDL or in the absence of lipoprotein species. These results suggest that TTR should be highly associated especially with VLDL/CM and amyloidogenicity of TTR should be enhanced around the adipocytes.

Amyloid deposition in ocular tissues of patients with familial amyloidotic polyneuropathy (FAP).

It is known that the severity of ocular symptoms does not always correlate with the systemic symptoms in patients with familial amyloidotic polyneuropathy (FAP ATTR V30M). The ocular tissues may have their own TTR metabolic system. The aim of this study is to clarify the distribution of amyloid deposition in the ocular tissues and to investigate the relationship between ocular symptoms and histopathological changes. We analyzed histopathologically 9 autopsied eyes taken from 3 Japanese and 6 Swedish patients with FAP ATTR V30M. Localization of amyloid deposition varied among the different cases, but there were some tendencies in the distribution. The degree of amyloid deposition in the ocular tissues was not always correlated with the duration of the disease. The frequency of amyloid deposition in the conjunctiva, iris, trabecular meshwork and vitreous body were 88.9%, 44.4%, 11.1% and 11.1% respectively in the 9 patients. These frequencies in the histopathological changes correlated with the frequencies in the clinical ocular manifestations as previously reported.

Amyloid formation in rat transthyretin: effect of oxidative stress.

BACKGROUND: Transgenic mice carrying a human mutant transthyretin (TTR) gene are too small for in vivo experiments. It is necessary to have rat TTR protein and its antibody to overcome this problem. METHODS: Posttranslational modification of purified TTR was analyzed by means of matrix-assisted laser desorption ionization/time-of-flight mass spectrometry (MALDI/TOF-MS). Production of amyloid fibrils in vitro was confirmed by thioflavin T test and electron microscopy. Amyloidogenicity of rat TTR from rats with or without challenging paraquat was compared in vitro by thioflavin T test. RESULTS: MALDI/TOF-MS for rat TTR revealed three major modified forms-sulfate-conjugated, Cys-conjugated and glutathione-conjugated-in addition to the unconjugated (free) form of TTR. Although rat TTR in buffer of pH 7.0 could not make amyloid fibrils, rat TTR at pH 2.0-3.5 significantly formed amyloid fibrils, as confirmed by the thioflavin T test and electron microscopy. TTR purified from rats administered 4 mg/kg of paraquat formed much more amyloid fibrils than that from normal rats at pH 2.0-3.5 and significant amyloid fibrils were confirmed even at pH 7.0. CONCLUSIONS: Rat TTR may be a valuable experimental tool for examination of the amyloidogenicity of senile systemic amyloidosis (SSA) as well as familial amyloidotic polyneuropathy (FAP) both in vitro and in vivo.

A novel localized amyloidosis associated with lactoferrin in the cornea.

We report a novel localized amyloidosis associated with lactoferrin. To elucidate the precursor protein of corneal amyloidosis associated with trichiasis, we analyzed amyloid deposits from three patients by histopathology and biochemistry. Amyloid deposits showed immunoreactivity, confirmed by electron microscopy, for only anti-human lactoferrin antibody. Electrophoresis of amyloid fibrils revealed lactoferrin with and without sugar chains; N-terminal sequence analysis revealed full-length lactoferrin and a truncated tripeptide of N-terminal amino acids, Gly-Arg-Arg. Carboxymethylated wild-type lactoferrin formed amyloid fibrils in vitro. Lactoferrin gene analysis in the three patients revealed a Glu561Asp mutation in all of the patients and a compound heterozygote of Ala11Thr and Glu561Asp mutations in one patient. A heterozygotic Glu561Asp mutation appeared in 44.8% of healthy Japanese volunteers, suggesting that the mutation may not be an essential mutation for amyloid formation (p = 0.104). Results thus suggest that lactoferrin is this precursor protein.

Decreased thermodynamic stability as a crucial factor for familial amyloidotic polyneuropathy.

A single mutation in the wild-type transthyretin (WT TTR) such as V30M causes a familial amyloidotic polyneuropathy disease. Comparison of the three-dimensional crystal structures of WT and V30M does not tell much about the reason. High-pressure NMR revealed that at neutral pH both WT and V30M exist as equilibrium between the native tetramer and the dissociated/unfolded monomer. The native tetramer is highly stable in WT (deltaG(0)=104 kJ/mol at 37 degrees C, pH 7.1), but the stability is significantly reduced in V30M (deltadeltaG(0)=-18 kJ/mol), increasing the fraction of the unfolded monomer by a 1000-fold. Significant reduction of thermodynamic stability of WT TTR by mutation could be a crucial factor for familial amyloidotic polyneuropathy.

Presence of autoantibody against ATTR Val30Met after sequential liver transplantation.

BACKGROUND: Recently, sequential liver transplantation has been performed with an explanted liver from a patient with familial amyloidotic polyneuropathy (FAP) because of the shortage of donors. However, metabolism of amyloidogenic transthyretin (ATTR), the pathogenic protein of FAP, has not been well studied in patients who have undergone sequential liver transplantation. The purpose of this study was to examine the changes in serum ATTR levels and to investigate the presence of an autoantibody in patients who underwent sequential liver transplantation with an explanted organ from a patient with heterozygotic FAP (FAP ATTR Val30Met). METHODS: This was a case study performed at the Kumamoto University School of Medicine, Kumamoto, Japan, and Kyoto University School of Medicine, Kyoto, Japan. Intervention occurred by sequential liver transplantation with an explanted FAP patient's liver. Levels of normal TTR and ATTR in the two patients who received the transplanted liver were analyzed by means of an enzyme-linked immunosorbent assay (ELISA) and a matrix-assisted laser desorption/time-of-flight mass spectrometry. In addition, the presence of an autoantibody against ATTR Val30Met was evaluated via ELISA using purified ATTR Val30Met from homozygotic FAP patients' sera. RESULTS: After the operation, the variant TTR levels were unexpectedly lower than levels of normal TTR in serum samples from patients with a transplanted liver from the FAP patient. An autoantibody against the variant TTR was detected on day 3 after the operation in the serum of those patients and continued to be present for at least 2 months after the operation. CONCLUSIONS: An autoantibody against the variant TTR may reduce the serum levels of variant TTR. Although the antibody may play a beneficial role in reducing the pathogenic protein, the long-term effect of the antibody must be investigated further.