Upregulated expression of glucose transporter isoform 1 in invasive and metastatic extramammary Paget's disease

Glucose transporter isoform 1 (GLUT1), which is upregulated in a variety of malignant tumors, facilitates cellular glucose uptake to boost rapid tumor growth and progression. In several types of cancer, inhibition of GLUT1 suppresses tumor proliferation and metastasis, indicating that GLUT1 is a potential target of anticancer therapy. The present study performed immunohistochemistry to analyze GLUT1 expression levels in 51 patients with extramammary Paget's disease (EMPD), including 23 with only intraepidermal lesions and 28 with dermal-invasive lesions. Of the 28 patients with dermal invasion, nine had available samples of lymph node metastasis. GLUT1 staining scores were significantly higher in dermal-invasive (P<0.0001) and metastatic lesions (P=0.0008) compared with in intraepidermal lesions. GLUT1 is upregulated during the transition from preinvasive to invasive or metastatic tumor in EMPD. Moreover, GLUT1 staining scores were statistically higher in intraepidermal tumor cells of dermal-invasive EMPD compared with tumor cells of only in situ EMPD (P=0.0338). GLUT1 is upregulated even during the preinvasive phase in patients with invasive EMPD, suggesting that GLUT1 immunostaining can predict the risk of dermal invasion. The present study provides novel evidence to pursue in vitro and in vivo studies to confirm that upregulated expression of GLUT1 enhances tumor aggressiveness in EMPD.

Significant increase in the prevalence of Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus, particularly the USA300 variant ΨUSA300, in the Japanese community

IMPORTANCE

USA300 is an MRSA clone producing PVL, a toxin associated with SSTIs. ΨUSA300 is a USA300 variant recently identified in Japan by Takadama et al. (15). Here, we found that the prevalence rate of PVL-positive MRSA in S. aureus was elevated in the Japanese community, and ΨUSA300 accounted for most of them. ΨUSA300 strains have been isolated from several areas in Japan and were associated with deep-seated SSTIs. This study highlighted the emerging threat posed by ΨUSA300 in Japan.

Case report: A case of epidermolysis bullosa acquisita with IgG and IgM anti-basement membrane zone antibodies relapsed after COVID-19 mRNA vaccination

We report a case of autoimmune bullous disease (AIBD) with IgG and IgM autoantibodies against epidermal basement membrane zone (BMZ), which showed recurrence of mucocutaneous lesions after coronavirus disease 2019 (COVID-19) mRNA vaccination. A 20-year-old Japanese woman with a 4-year history of epidermolysis bullosa acquisita (EBA) presented to our clinic. She noticed fever and rash on the same day and visited at our hospital 2 days later. Physical examination revealed blisters, erosions and erythema on the face, shoulder, back, upper arms, and lower lip. A skin biopsy from the forehead showed subepidermal blister. Direct immunofluorescence showed linear depositions of IgG, IgM, and C3c in the epidermal BMZ. By indirect immunofluorescence of 1M NaCl-split normal human skin, circulating IgG autoantibodies were bound to the dermal side of the split at 1:40 serum dilution, and circulating IgM antibodies were bound to the epidermal side of the spilt. After the increase of prednisolone dose to 15 mg/day, the mucocutaneous lesions resolved in a week. The present case is the first case of possible EBA with IgG and IgM anti-BMZ antibodies, in which the mucocutaneous lesions were recurred after COVID-19 mRNA vaccination. Clinicians should be aware that bullous pemphigoid-like AIBDs, including EBA and IgM pemphigoid, might be developed after COVID-19 mRNA vaccination.

A case of COVID ‐19 with pernio‐like skin lesions and increased red blood cell distribution width

Heparin resistance has been observed in patients with active severe COVID‐19 infection. The red blood cell distribution (RDW), a component of the complete blood count that reflects cellular volume variation, has been shown to be associated with elevated risk for morbidity and mortality in a wide range of diseases. Cutaneous manifestations, RDW, and levels of LD and D‐dimer might be useful biomarkers in triage of patients with COVID‐19.

A Case of Anti-BP180-type Mucous Membrane Pemphigoid with IgG and IgA Autoantibodies Showing Distinct Reactivities

Dear Editor, Mucous membrane pemphigoid (MMP) is an autoimmune blistering disease characterized by erosive mucosal lesions mainly on the oral and ocular mucosae (1). We report a case of oral and ocular anti-BP180-type MMP with variable IgG and IgA reactivities and underlying dementia. An 84-year-old Japanese man presented with a 4-year history of erosions in the oral cavity and on the conjunctivae, with progressive vision impairment. The medical history included benign prostatic hyperplasia, cataract, sinusitis, and dementia. Physical examination revealed erosions and white atrophic scars along the gingival mucosa and on the hard palate (Figure 1, a, b). Conjunctival inflammation and corneal scarring were also observed only on the left eye (Figure 1, c, d). No lesions were observed on the skin or on any other mucosae. A skin biopsy from the patient's oral mucosa showed lymphocytic infiltration in the superficial dermis without apparent subepithelial blister. Direct immunofluorescence showed linear depositions of IgG, IgA, and C3 at the epithelial basement membrane zone (Figure 1, e-g). Circulating IgG and IgA autoantibodies were not detected by indirect immunofluorescence of normal human skin, while circulating IgA, but not IgG, autoantibodies were bound to the epidermal side of 1M NaCl-split normal human skin at 1:10 serum dilution (Figure 1, h, i). Commercially available IgG enzyme-linked immunosorbent assays (ELISAs) of BP180 NC16a domain, BP230, and type VII collagen (MBL, Nagoya, Japan) showed negative results. IgG and IgA immunoblotting analyses of six different antigen sources, including BP180 C-terminal domain recombinant protein, were all negative. However, ELISA of full-length BP180 was slightly positive for IgG antibodies (index = 5.79; cut-off <4.64). Immunoblotting analysis of full-length BP180 was negative for both IgG and IgA antibodies (Figure 1, j, k). Immunoblotting analysis of hemidesmosome-rich fraction was negative for both IgG and IgA antibodies to integrin β4 (Figure 1, l). Based mainly on the clinical and immunological findings, we established a diagnosis of MMP with IgG and IgA autoantibodies, likely reactive with BP180. Because the patient refused systemic treatments, we prescribed a mouth rinse sodium gualenate hydrate and eyedrops of fluorometholone and purified sodium hyaluronate, which did not improve the oral and ocular mucosal symptoms during the 8 month follow-up period (Figure 1, m, n). Both IgG and IgA autoantibodies in anti-BP180-type MMP tend to react with the C-terminal domain of BP180 (2), and IgG autoantibodies in 39.7% of MMP patients reactive with the epidermal side of split skin were reported to be positive with BP180 C-terminal domain (3). The full-length BP180 ELISA shows excellent sensitivity for diagnosing BP180-type MMP (4). The different IgG and IgA reactivities among various methods used in the present study may be attributed either to different methodologies (i.e., immunoblotting or ELISA) or to the different substrates, since BP180-type MMP targets various regions of BP180, including the NC16a domain, the C-terminal domain, and the intracytoplasmic region (5). Precise diagnosis for MMP by various immunological methods is critical, because urgent and extensive treatments are necessary for the ocular and laryngeal lesions, which may result in loss of eyesight and airway obstruction, respectively. Acknowledgments: We express our gratitude to Ms. Mako Mine and Dr. Daisuke Hayashi, Department of Dermatology, Osaka City University Graduate School of Medicine in Osaka, Japan for the HD-rich fraction immunoblotting analysis, and Dr. Yoshiaki Hirako, Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan for the preparation of the HD-rich fraction sample. This work was supported by JSPS KAKENHI Grant Number JP20k08684 and the Hirosaki University Research Support System.

Enhanced β-adrenergic response in mice with dominant-negative expression of the PKD2L1 channel

Polycystic kidney disease (PKD) is the most common genetic cause of kidney failure in humans. Among the various PKD-related molecules, PKD2L1 forms cation channels, but its physiological importance is obscure. In the present study, we established a transgenic mouse line by overexpressing the dominant-negative form of the mouse PKD2L1 gene (i.e., lacking the pore-forming domain). The resulting PKD2L1del-Tg mice exhibited supraventricular premature contraction, as well as enhanced sensitivity to β-adrenergic stimulation and unstable R-R intervals in electrocardiography. During spontaneous atrial contraction, PKD2L1del-Tg atria showed enhanced sensitivity to isoproterenol, norepinephrine, and epinephrine. Action potential recording revealed a shortened action potential duration in PKD2L1del-Tg atria in response to isoproterenol. These findings indicated increased adrenergic sensitivity in PKD2L1del-Tg mice, suggesting that PKD2L1 is involved in sympathetic regulation.

A Case of Possible Concurrence of Dermatitis Herpetiformis and Linear Immunoglobulin A / Immunoglobulin G Bullous Dermatosis

Dear Editor, Linear immunoglobulin (Ig) A bullous dermatosis (LABD), one subtype of subepidermal autoimmune bullous skin diseases (AIBDs), is characterized by linear deposit of only IgA along the basement membrane zone (BMZ) on direct immunofluorescence (DIF) (1,2). Patients showing linear deposits of both IgA and IgG are diagnosed with linear IgA/IgG bullous dermatosis (LAGBD) (3,4). Dermatitis herpetiformis (DH) is another type of subepidermal AIBD characterized by clinically pruritic erythematous skin lesions with vesicles on the elbows, knees, and buttocks with granular IgA deposits of IgA by DIF (5). In this study, we report a Japanese case of a patient who showed possible concurrence of DH and LAGBD based on clinical, histological, and immunological findings. A 72-year-old Japanese man who had a past history of dyslipidemia and resected lung cancer but was not taking any medicines, presented with a one-year history of blistering skin lesions. Physical examination revealed erythemas and peripherally arranged vesicles and erosions on the bilateral elbows, knees, and the buttock (Figure 1, a-c). Mucous membranes were not involved. The results of all laboratory tests were within normal ranges, except for increased serum IgA level 351 mg/dL (normal ranges; 46-260 mg/dL). Skin biopsy histopathologically showed subepidermal blisters infiltrated with neutrophils and eosinophils (Figure 1, d). DIF showed deposits of IgG, IgA, and complement component 3 along the BMZ mainly in granular but partially in a linear pattern (Figure 1, e-g). Circulating IgG (Figure 1, h) and IgA (Figure 1, i) autoantibodies were not detected by indirect immunofluorescence (IIF) of normal skin, however, circulating IgA (Figure 1, j) but not IgG (Figure 1, k) antibodies were bound to both the epidermal and dermal sides by IIF of 1M NaCl-split normal skin. Commercially available enzyme-linked immunosorbent assays (ELISAs) for BP180 NC16a domain, BP230, and type Vll collagen (MBL, Nagoya, Japan), showed negative results for both IgG and IgA antibodies. IgG in-house ELISA for full length BP180 was also negative. IgG and IgA immunoblotting analyses of different antigen sources, including normal human epidermal and dermal extracts, recombinant proteins of NC16a, and C-terminal domains of BP180 region, BP230, purified laminin 332, and concentrated culture supernatant of HaCaT cells for LAD-1, were all negative. IgA ELISAs of tissue- and epidermal-transglutaminases were negative (1.92 AU/mL and 20.98 AU/mL, respectively; normal range <22.0 AU/mL). The patient was successfully treated with only topical corticosteroids with occasional mild local relapses. Japanese DH is different from European DH in some respects, i.e., DH is very rare in Japan due to genetic/HLA difference, absence of celiac disease, and frequent fibrillar IgA deposition in DIF. Therefore, we believe that this case is interesting as a rare Japanese DH case with complicated conditions. The clinical and immunochemical characteristics in the present case were compatible for both DH and LAGBD. Clinical features of vesicles on erythemas on the knees and buttock suggested DH, while histopathological features were compatible with LAGBD but also with DH, DIF results suggested both LAGBD and DH, and the results of IIF of 1M NaCl-split skin suggested LAGBD. All biochemical studies for autoantigens were negative, which suggested DH. However, autoantigens are not clearly detected in many LAGBD cases, either. IgA anti-epidermal transglutaminase antibody, a DH marker, was negative, but the titer was relatively high but within normal range. Therefore, we considered that this case might have developed DH and LAGBD concurrently. However, there may be two other possibilities: [1] this case was DH and non-pathogenic circulating autoantibodies were secondary production, and [2] LAGBD cases may sometimes show granular-linear BMZ deposition of IgG and IgA. Future studies on similar cases are needed to clarify our speculations.

Attenuated β-adrenergic response in calcium/calmodulin-dependent protein kinase IV-knockout mice

In the present study, we examined the importance of Ca2+/calmodulin-dependent protein kinase IV (CaMKIV) in the regulation of cardiac function using genetically modified CaMKIV-null mice. RT-PCR analysis revealed decreased expression of voltage-dependent calcium channels in the cardiac myocytes of CaMKIV-null mice compared with wild-type mice. CaMKIV-null mice showed shortened QT time on electrocardiograms. Pharmacological analysis revealed decreased responsiveness to the β-adrenergic blocker propranolol in CaMKIV-null mice, whereas the plasma norepinephrine level was not affected. CaMKIV-null mice showed decreased baroreflex on electrocardiograms. Heart rate variability analysis showed unstable R-R intervals, a decreased low frequency power/high frequency power (LF/HF) ratio, and increased standard deviation of the normal to normal R-R intervals (SDNN) in CaMKIV-null mice, suggesting decreased responsiveness to β-adrenergic stimulation in CaMKIV-null mice. Atrial contraction analysis and cardiac action potential recording showed a decreased response to the β-adrenoceptor agonist isoproterenol in CaMKIV-null mice. Furthermore, fluorescence imaging in a CRE-hrGFP assay revealed a decreased response to isoproterenol in CaMKIV-null cardiac myocytes. Taken together, our data strongly suggest a significant effect of CaMKIV gene ablation on cardiac β-adrenergic signal transduction.

Autoantibodies to BPAG1e Trigger Experimental Bullous Pemphigoid in Mice

Bullous pemphigoid (BP) is an autoimmune blistering disease that targets the hemidesmosomal proteins BP180 and BP230/BPAG1e. Whereas the role of anti-BP180 antibodies has been extensively characterized, the pathogenicity of anti-BPAG1e antibodies remains unclear. The purpose of this study is to elucidate the role of antibodies to BPAG1e in the experimental bullous pemphigoid models. We generated Bpag1 conditional knockout mice, where the knockout of Bpag1 is restricted to keratin 5-expressing epithelial cells. Bpag1 conditional knockout mice were immunized with the C-terminal portion of BPAG1e, and the splenocytes were injected into Rag2^-/- mice intravenously. The recipient mice presented with erosion on the feet and tails. Microscopic examination showed subepidermal blisters and a linear deposition of IgG at the dermal-epidermal junction. To assess the potential role of trauma on BP development, we inflicted surface wounds on the dorsum of the Rag2^-/- recipient mice after adoptive transfer. The wounded Rag2^-/- mice had increased morbidity and severity of BP-like symptoms. Moreover, the depletion of B cells from splenocytes abolished a subepidermal blistering phenotype in vivo. These findings demonstrate that antibodies to BPAG1e might play a pathogenic role in causing subepidermal blistering, and external factors, including trauma, might be a trigger for BP development.

Current status of Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus isolated from patients with skin and soft tissue infections in Japan

The USA300 clone, which produces Panton-Valentine leukocidin (PVL), is a major pathogenic community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) clone that causes intractable skin infections. Recently, PVL-positive CA-MRSA, including USA300 clones, have emerged in both communities and hospitals in Japan. To prevent an outbreak of PVL-positive MRSA, infected patients should be treated with effective antimicrobial agents at community clinics. Herein, we investigate molecular epidemiological characteristics of PVL-positive MRSA isolated from outpatients with skin and soft tissue infections (SSTI), which are common community-onset infectious diseases. The detection rate of MRSA was 24.9% (362 strains) out of 1455 S. aureus strains isolated between 2013 and 2017. Among the MRSA strains, 15.5% (56 strains) were PVL-positive strains and associated with deep-seated skin infections. Molecular epidemiological analyses of PVL-positive MRSA showed that USA300 was the predominant clone (53.6%, 30 strains) and was identified in Kanto (18 strains), Kagawa (nine strains), Tohoku (two strains) and Hokkaido (one strain). Notably, minocycline and fusidic acid were effective against all PVL-positive MRSA strains. Hence, our data reveals the current status of PVL-positive MRSA isolated from patients with SSTI in Japan. Continuous surveillance of CA-MRSA is necessary to monitor latest prevalence rates and identify effective antimicrobial agents for PVL-positive MRSA strains.

Effects of Zinc Acetate on Serum Zinc Concentrations in Chronic Liver Diseases: a Multicenter, Double-Blind, Randomized, Placebo-Controlled Trial and a Dose Adjustment Trial

The essential trace element zinc maintains liver functions. Liver diseases can alter overall zinc concentrations, and hypozincemia is associated with various hepatic pathologies. Modulating systemic zinc through dietary supplementation is potentially useful for liver diseases. We evaluated the usefulness of zinc (NPC-02; acetate formulation) supplementation. We conducted two NPC-02 studies on zinc-deficient patients (serum zinc < 70 μg/dL). Study 1: double-blind, randomized, placebo-controlled trial on 57 subjects with chronic liver diseases comparing serum zinc in patients given NPC-02 (NPC-02 group) versus placebo (Placebo group). Study 2: dose adjustment study on 43 subjects with/without liver diseases to determine proportions maintaining serum zinc target (≥ 80 μg/dL but < 200 μg/dL). In study 1, NPC-02 subjects had higher serum zinc concentrations at week 8 than Placebo subjects (83.2 ± 20.2 and 61.3 ± 12.0, respectively; P < 0.0001), and more NPC-02 than Placebo subjects achieved the serum zinc target (15/27 vs. 1/26). In study 2, the NPC-02-induced serum zinc increase was dose-dependent in subjects both with and without liver diseases (r = 0.5143, P = 0.0022 and r = 0.5753, P = 0.0005, respectively). Interestingly, there was a marginally positive correlation between serum zinc and albumin levels in subjects with but not in those without liver diseases (r = 0.4028, P = 0.0631 and r = 0.1360, P = 0.5567, respectively). NPC-02 dose-dependently increases serum zinc in hypozincemic patients, regardless of liver disease. NPC-02 is a potentially effective therapy for liver cirrhosis, in which zinc deficiency is common. Clinical trial registry number: NCT02337569, NCT02321865.

Bezafibrate Improves GLOBE and UK-PBC Scores and Long-Term Outcomes in Patients With Primary Biliary Cholangitis

In Japan, bezafibrate (BF) is a second-line agent for primary biliary cholangitis (PBC) that is refractory to ursodeoxycholic acid (UDCA) treatment. From a retrospective cohort (n = 873) from the Japan PBC Study Group, we enrolled 118 patients who had received UDCA monotherapy for at least 1 year followed by combination therapy with UDCA+BF for at least 1 year. GLOBE and UK-PBC scores after UDCA monotherapy (i.e., immediately before UDCA+BF combination therapy) were compared with those after 1 year of UDCA+BF combination therapy. The real outcomes of enrolled patients estimated by Kaplan-Meier analysis were compared with the predicted outcomes calculated using GLOBE and UK-PBC scores. In addition, the hazard ratio of BF treatment was calculated using propensity score analysis. The mean GLOBE score before the combination therapy was 0.504 ± 0.080, which improved significantly to 0.115 ± 0.085 (P < 0.0001) after 1 year of combination therapy. The real liver transplant-free survival of enrolled patients was significantly better than that predicted by GLOBE score before introducing BF. Combination therapy did not significantly improve the real rates of liver transplantation or liver-related death compared with those predicted by UK-PBC risk score before introducing BF, but the predicted risk was significantly reduced by the addition of BF (P < 0.0001). Cox regression analysis with inverse probability of treatment weighting showed that the addition of BF significantly reduced the hazard of liver transplant or liver-related death in patients who, after 1 year of UDCA monotherapy, had normal serum bilirubin (adjusted hazard ratio 0.09, 95% confidence interval 0.01-0.60, P = 0.013). Conclusion: Addition of BF to UDCA monotherapy improves not only GLOBE and UK-PBC scores but also the long-term prognosis of PBC patients, especially those with early-stage PBC.

Green tea polyphenol (epigallocatechin-3-gallate) improves gut dysbiosis and serum bile acids dysregulation in high-fat diet-fed mice

Gut microbiota have profound effects on bile acid metabolism by promoting deconjugation, dehydrogenation, and dehydroxylation of primary bile acids in the distal small intestine and colon. High-fat diet-induced dysbiosis of gut microbiota and bile acid dysregulation may be involved in the pathology of steatosis in patients with non-alcoholic fatty liver disease. Epigallocatechin-3-gallate (EGCG), the most abundant polyphenolic catechin in green tea, has been widely investigated for its inhibitory or preventive effects against fatty liver. The aim of the present study was to investigate the effects of EGCG on the abundance of gut microbiota and the composition of serum bile acids in high-fat diet-fed mice and determine the specific bacterial genera that can improve the serum bile acid dysregulation associated with EGCG anti-hepatic steatosis action. Male C57BL/6N mice were fed with the control diet, high-fat diet, or high-fat diet + EGCG at a concentration of 0.32% for 8 weeks. EGCG significantly inhibited the increases in weight, the area of fatty lesions, and the triglyceride content in the liver induced by the high-fat diet. Principal coordinate analysis revealed significant differences in microbial structure among the groups. At the genus level, EGCG induced changes in the microbiota composition in high-fat diet-fed mice, showing a significantly higher abundance of Adlercreutzia, Akkermansia, Allobaculum and a significantly lower abundance of Desulfovibrionaceae. EGCG significantly reversed the decreased population of serum primary cholic acid and β-muricholic acid as well as the increased population of taurine-conjugated cholic acid, β-muricholic acid and deoxycholic acid in high-fat diet-fed mice. Finally, the correlation analysis between bile acid profiles and gut microbiota demonstrated the contribution of Akkermansia and Desulfovibrionaceae in the improvement of bile acid dysregulation in high-fat diet-fed mice by treatment with EGCG. In conclusion, the present study suggests that EGCG could alter bile acid metabolism, especially taurine deconjugation, and suppress fatty liver disease by improving the intestinal luminal environment.

Efficacy of direct-acting antiviral treatment in patients with compensated liver cirrhosis: A multicenter study

AIM

Although the development of new direct-acting antivirals (DAAs) for the treatment of chronic hepatitis C virus (HCV) infection has markedly advanced, the effects of cirrhosis on DAA treatment remain unclear. We aimed to clarify the impact of cirrhosis on DAA treatment of patients infected with HCV.

METHODS

This large-scale, multicenter, retrospective study consisted of 2130 HCV genotype 1b-infected patients who were treated with one of the following DAA combination therapies: asunaprevir/daclatasvir (ASV/DCV), ledipasvir/sofosbuvir (LDV/SOF), or paritaprevir/ombitasvir/ritonavir (PTV/OBV/r). Ninety-two patients (4.3%) previously received DAA-based treatment. Seven hundred and forty-five patients (34.9%) had cirrhosis.

RESULTS

Overall, the sustained virologic response (SVR) rate was 93.0%. The SVR rates in patients who received ASV/DCV, LDV/SOF, or PTV/OBV/r were 90.0%, 96.9%, and 97.6%, respectively. The SVR rate in patients with cirrhosis (89.1%) was significantly lower than that in patients without cirrhosis (95.1%, P = 6.94 × 10^-7 ). In the multivariate analysis for the overall cohort, absence of cirrhosis (P = 1.26 × 10^-3 ), no previous DAA-based treatment (P = 2.54 × 10^-14 ), low HCV-RNA levels (P = 1.64 × 10^-6 ), wild-type non-structural protein 5A L31/Y93 (P = 7.33 × 10^-13 ), and DAA regimen (LDV/SOF or PTV/OBV/r) (P = 1.92 × 10^-14 ) were independent factors contributing to SVR. Except for patients with DAA-based treatment history, absence of cirrhosis (P = 2.15 × 10^-3 ; odds ratio, 2.51) was an independent factor contributing to SVR in 2038 DAA-naïve patients.

CONCLUSION

This study suggests that the presence of cirrhosis reduces the SVR rate of DAA treatment, regardless of the type of DAA treatment.

Analysis of 307 cases with drug-induced liver injury between 2010 and 2018 in Japan

AIM

In order to know the present status of drug-induced liver injury (DILI) in Japan, we present the data of prospectively collected DILI cases between 2010 and 2018 from 27 hospitals.

METHODS

Drug-induced liver injury cases diagnosed by DILI experts from 27 hospitals all over Japan have been prospectively collected since 2010. Alanine aminotransferase level ≥150 U/L and/or alkaline phosphatase ≥2× upper limit of normal were inclusion criteria.

RESULTS

In total, data of 307 cases (125 male and 182 female individuals) aged between 17 and 86 years old were collected. The types of liver injury were as follows: 64% hepatocellular type, 20% mixed type, and 16% cholestatic type. A drug-induced lymphocyte stimulation test was carried out in 59% of cases, and was positive in 48% and semipositive in 3% of cases. Eosinophilia ≥6% was observed in 27% of cases. Fifty-three percent of DILI cases occurred within 30 days and 79% of DILI cases occurred within 90 days after starting drug administration. By the diagnostic scale of the Digestive Disease Week (DDW)-Japan 2004 workshop, 93.8% of cases were diagnosed as "highly probable", and 5.9% as "possible".

CONCLUSIONS

Japanese DILI patients are somewhat different from those of Europe and North America. The diagnostic scale of the DDW-Japan 2004 workshop has been used in Japan. However, there are many issues to improve the causality assessment of DILI that we must investigate in the future. It is critical to elucidate the mechanisms of drug metabolism and the pathophysiology of liver injury by various drugs to prevent DILI.

Influences of Taurine Deficiency on Bile Acids of the Bile in the Cat Model

Taurine content in the body is maintained by both biosynthesis from sulfur-contained amino acids in the liver and ingestion from usual foods, mainly seafoods and meat. Contrary to the rodents, the maintenance of taurine content in the body depends on the oral taurine ingestion in cats as well as humans because of the low ability of the biosynthesis. Therefore, insufficient of dietary taurine intake increases the risks of various diseases such as blind and expanded cardiomyopathy in the cats. One of the most established physiological roles of taurine is the conjugation with bile acid in the liver. In addition, taurine has effect to increase the expression and activity of bile acid synthesis rate-limiting enzyme CYP7A1. Present study purposed to evaluate the influence of taurine deficiency on bile acids in the cats fed taurine-lacking diet. Adult cats were fed the soybean protein-based diet with 0.15% taurine or without taurine for 30 weeks. Taurine concentration in serum and liver was undetectable, and bile acids in the bile were significantly decreased in the taurine-deficient cats. Taurine-conjugated bile acids in the bile were significantly decreased, and instead, unconjugated bile acids were significantly increased in the taurine-deficient cats. Present results suggested that the taurine may play an important role in the synthesis of bile acids in the liver.

The comparison of the intensity of human intestinal spirochetes between Brachyspira pilosicoli and Brachyspira aalborgi infections

The agglutination titers of Brachyspira pilosicoli (B. pilosicoli) and Brachyspira aalborgi (B. aalborgi) were examined in colitis patients with human intestinal spirochetes. Among three cases of colitis patients, the titer of B. pilosicoli was extremely high in two cases while the titer of B. aalborgi was extremely high in one case. These three cases had symptoms of colitis, such as watery diarrhea, and we diagnosed the case as Brachyspira- related colitis. These findings suggest that the agglutination titers of Brachyspira may be useful in cases of Brachyspira- related colitis. Severe symptoms, such as abdominal pain and diarrhea, were observed in cases with high antibody titer of B. aalborgi, as well as B. pilosicoli, indicating that B. aalborgi could also cause symptomatic colitis.

Human-specific dual regulations of FXR-activation for reduction of fatty liver using in vitro cell culture model

Nuclear receptor farnesoid X receptor activation inhibits fatty acid synthesis through the liver X receptor-α-sterol regulatory element binding protein-1c pathway universally in animals, but also has human-specific crosstalk with the peroxisome proliferator-activated receptor-α. The effects of farnesoid X receptor-ligands on both the synthesis and degradation of fatty liver through nuclear receptor-related regulation were investigated in both human and murine hepatocytes. A fatty liver culture cell model was established using a synthetic liver X receptor-α-ligand (To901317) for both human and mouse non-neoplastic hepatocytes. The hepatocytes were exposed to natural or synthetic farnesoid X receptor-ligands (bile acids, GW4064, obeticholic acid) together with or after To901317. Cellular triglyceride accumulation was significantly inhibited by the farnesoid X receptor-ligands along with inhibition of lipogenic genes and up-regulation of farnesoid X receptor-target small heterodimer partner in both human and mouse cells. The accumulated triglyceride was significantly degraded by the farnesoid X receptor-ligands only in the human cells accompanied with the up-regulations of peroxisome proliferator-activated receptor-α and fatty acid β-oxidation. Farnesoid X receptor-ligands can be therapeutic agents for treating human fatty liver through dual effects on inhibition of lipogenesis and on enhancement of lipolysis.

Increased N-Acetyltaurine in the Skeletal Muscle After Endurance Exercise in Rat

Taurine is metabolized to a novel metabolite, N-acetyltaurine (NAT), through N-acetylation with acetate. Furthermore, NAT production increases when the endogenous production of acetate is elevated in some situations, such as alcohol catabolism and endurance exercise. We have previously reported that both the serum concentration and urinary excretion of NAT from humans were increased after endurance exercise, and that NAT was secreted by cultured skeletal muscle cells exposed to both acetate and taurine. The present study evaluated the hypothesis that NAT is synthesized in the skeletal muscle after endurance exercise. Normal rats were loaded to a transient treadmill running until exhaustion. Serum, skeletal muscle, and liver were collected immediately after the exercise. The NAT concentration in the plasma and in the soleus muscle from the exercised rats was significantly increased compared to that in the samples from the sedentary control rats. There was a significant positive correlation in the NAT concentration between the plasma and soleus muscle. The NAT concentration in the liver was unchanged after the endurance exercise. These results confirm that the significantly increased NAT in both the serum and urine after endurance exercise is derived from NAT synthesis in the skeletal muscle.

Is patient-reported outcome improved by nalfurafine hydrochloride in patients with primary biliary cholangitis and refractory pruritus? A post-marketing, single-arm, prospective study

BACKGROUND

Patients with primary biliary cholangitis (PBC) frequently suffer from pruritus, which can severely impair their health-related quality of life (HRQOL). Nalfurafine hydrochloride, a selective κ-opioid receptor agonist, was recently approved in Japan for refractory pruritus in patients with chronic liver diseases, but it still remains unclear whether this treatment improves the patient-reported outcome (PRO) in PBC patients with refractory pruritus. Herein, we conducted a multicenter, post-marketing, single-arm prospective study to investigate the efficacy of nalfurafine in terms of PRO, and the associations of the efficacy with any clinical characteristics.

METHODS

After screening for pruritus in 496 patients with PBC using PBC-40 and the visual analog scale (VAS), we identified 141 patients with moderate to severe pruritus; these were invited to participate in the study. The participants received 2.5 μg nalfurafine once daily for 12 weeks, and pruritus and HRQOL were assessed in week 12 of this treatment. Generic HRQOL, short form 36, blood chemistries, and serum autotaxin levels were also measured at baseline and at week 12.

RESULTS

Forty-four patients participated in this study. The mean PBC-40 itch domain scores and VAS declined during the study period, from 8.56 to 7.63 (P = 0.041) and from 42.9 to 29.3 (P = 0.001) at baseline and at week 12, respectively, indicating a significant effect of nalfurafine. The other domains of PBC-40 and all domains of SF-36 were not significantly altered by this treatment. We failed to find any association between the change in VAS and PBC-40 itch scores and any clinical variable. Serum autotaxin levels were significantly increased during the study period.

CONCLUSIONS

This study demonstrated that nalfurafine improved pruritus in patients with PBC, independent of their clinical characteristics, but had a limited effect on the PRO.

Ledipasvir-sofosbuvir for treating Japanese patients with chronic hepatitis C virus genotype 2 infection

BACKGROUND & AIMS

Japanese patients with chronic hepatitis C virus (HCV) genotype 2 infection have high rates of sustained virological response (SVR) following 12 weeks of treatment with the nucleotide polymerase inhibitor sofosbuvir in combination with ribavirin, which was the standard of care at the time this study was undertaken. We assessed the efficacy of 12 weeks of treatment with a ribavirin-free regimen of ledipasvir-sofosbuvir.

METHODS

In an open-label, Phase 3 trial we enrolled Japanese patients with chronic HCV genotype 2 infection, with or without compensated cirrhosis. In Cohort 1, participants were randomized 1:1 to receive ledipasvir-sofosbuvir (n = 106) or sofosbuvir + ribavirin (n = 108) for 12 weeks. In Cohort 2, 25 ribavirin-intolerant or -ineligible patients received ledipasvir-sofosbuvir for 12 weeks. The primary endpoint was SVR 12 weeks after therapy (SVR12). In Cohort 1 non-inferiority was assessed with a prespecified margin of 10%.

RESULTS

One-third (33%) of patients were treatment experienced, and 14% had cirrhosis. In Cohort 1, SVR12 rates were 96% (95% CI, 91% to 99%) with ledipasvir-sofosbuvir and 95% (95% CI, 90% to 98%) with sofosbuvir plus ribavirin, thus achieving non-inferiority. Among ribavirin-intolerant/ineligible patients in Cohort 2, SVR12 was 96% (95% CI, 80% to 100%) with ledipasvir-sofosbuvir. Overall, the most common adverse events were nasopharyngitis, anaemia, and headache; anaemia was only observed in patients receiving ribavirin. The percentage of patients who discontinued treatment because of an adverse event was low (1%).

CONCLUSIONS

Among Japanese patients with HCV genotype 2, 12 weeks of treatment with ledipasvir-sofosbuvir resulted in high rates of SVR12 that were non-inferior to sofosbuvir + ribavirin.

Agaro-Oligosaccharides Regulate Gut Microbiota and Adipose Tissue Accumulation in Mice

Gut microbiota are deeply associated with the prevalence of obesity. Agarose is hydrolyzed easily to yield oligosaccharides, designated as agaro-oligosaccharides (AGO). This study evaluated the effects of AGO on obese phenotype and gut microbial composition in mice. Mice were administered AGO in drinking water (AGO-receiving mice). 16S rRNA gene sequencing analyses revealed their fecal microbiota profiles. Serum bile acids were ascertained using a LC-MS/MS system. Compared to the control group, AGO administration significantly reduced epididymal adipose tissue weights and serum non-esterified fatty acid concentrations, but the cecal content weights were increased. Data from the serum bile acid profile show that concentrations of primary bile acids (cholic acid and chenodeoxycholic acid), but not those of secondary bile acids (deoxycholic acid, lithocholic acid, and ursodeoxycholic acid), tended to increase in AGO-receiving mice. 16S rRNA gene sequencing analyses showed that the relative abundances of 15 taxa differed significantly in AGO-receiving mice. Of these, the relative abundances of Rikenellaceae and Lachnospiraceae were found to be positively correlated with epididymal adipose tissue weight. The relative abundances of Bacteroides and Ruminococcus were correlated negatively with epididymal adipose tissue weight. Although the definitive role of gut microbes of AGO-received mice is still unknown, our data demonstrate the possibility that AGO administration affects the gut microbial composition and inhibits obesity in mice.

Efficacy and safety of ombitasvir/paritaprevir/ritonavir combination therapy for genotype 1b chronic hepatitis C patients complicated with chronic kidney disease

AIM

The aim of this study was to clarify the effects and safety of ombitasvir/paritaprevir/ritonavir (OBT/PTV/r) therapy in genotype 1b chronic hepatitis C patients with non-dialysis chronic kidney disease (CKD).

METHODS

This retrospective, multicenter study of 12-week OBT/PTV/r therapy included genotype 1b patients with non-dialysis CKD. Chronic kidney disease was defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² . Virologic responses and treatment-emergent adverse events (TEAEs) in patients with CKD were compared with those in patients without CKD.

RESULTS

Two hundred and thirty-five patients with a median age of 67 years (range, 27-89 years) were enrolled, consisting of 181 patients without CKD and 54 patients with CKD. Overall, the rates of rapid virologic response (RVR), end of treatment response (ETR), and sustained virologic response (SVR) were 78.7%, 98.7%, and 98.7%, respectively. Among the 181 non-CKD patients, the rates were 77.3% (140/181), 98.9% (179/181), and 98.9% (179/181), respectively. Among the 54 CKD patients, the rates were 83.3% (45/54), 98.1% (53/54), and 98.1% (53/54), respectively. There were no significant differences in the virologic response rates between the two groups (P = 0.449 for RVR, 0.545 for ETR, and 0.545 for SVR). In the CKD group, the eGFR level did not significantly change throughout the treatment period. There was no significant difference in the incidence of TEAEs or treatment discontinuation due to TEAEs between the two groups.

CONCLUSION

The present study showed that the effects and safety of OBV/PTV/r therapy in genotype 1b chronic hepatitis C patients with non-dialysis CKD were not inferior to those in patients without CKD.

Analysis of factors predicting the response to tolvaptan in patients with liver cirrhosis and hepatic edema

BACKGROUND AND AIM

This study aimed to clarify the factors predictive of treatment response to tolvaptan (V2-receptor antagonist) for cirrhotic patients with hepatic edema in a real-world setting.

METHODS

In this retrospective, multicenter study, tolvaptan was orally administered at a dose of 7.5 mg once a day. Patients with a decrease in body weight of 1.5 kg or greater from baseline were characterized as responders at day 7.

RESULTS

Of 229 patients, 210 were subjected to this analysis. Patients consisted of 133 men and 77 women, with the median age of 67 years (range, 40-89 years). According to the Child-Pugh classification, five patients were classified as class A, 90 as class B, and 115 as class C. The frequencies of responders and nonresponders were 55.2% and 44.8%, respectively. Blood urea nitrogen (BUN) level was significantly lower in responders compared with nonresponders (P = 3.77 × 10^-3 ). Using the receiver operating characteristic curve, the cutoff value of 28.2 mg/dL was the most useful in discriminating responders from nonresponders. Among 154 patients with BUN level of less than 28.2 mg/dL, 95 (61.7%) were responders. By contrast, among 56 patients with BUN level of 28.2 mg/dL or more, 21 (37.5%) were nonresponders (P = 2.70 × 10^-3 ). On multivariate analysis, BUN level of <28.2 mg/dL and urine sodium >51 mEq/day were found to be independent factors associated with the response to tolvaptan.

CONCLUSIONS

This study suggests that BUN level and urinary sodium excretion are closely associated with the response to tolvaptan in cirrhotic patients with hepatic edema.

Differences in the Serum 4β-hydroxycholesterol Levels of Patients with Chronic Hepatitis C Virus (HCV) Infection: A Possible Impact on the Efficacy and Safety of Interferon (IFN)-free Treatment

Objective Since the majority of direct-acting antivirals (DAAs) that are used in the treatment of hepatitis C virus (HCV) infection are mainly metabolized by CYP3A4, it is hypothesized that inter-individual differences in CYP3A4 activity may be associated with the bioavailability of these agents. Methods The level of serum 4β-hydroxycholesterol (4βHC), a surrogate marker of CYP3A4 activity, was determined by LC-MS/MS in samples obtained from patients with HCV infection (CHCs) as well as healthy control subjects (CTLs). Serum samples obtained from patients treated with either asunaprevir/daclatasvir (ASV/DCV) or ombitasvir/paritaprevir/ritonavir (OTV/PTV/r) were used for additional assays. Results The serum 4βHC level in CHCs was significantly higher than that in CTLs, and a gender difference was seen among CHCs. In patients treated with OTV/PTV/r, the serum 4βHC level was observed to gradually decrease during the treatment period. In the cohort treated with ASV/DCV, 4 of 83 patients showed virological treatment failure. In pretreatment testing, an Invader assay detected a low prevalence of resistance-associated variants in these four patients. The average serum concentration of DCV/ASV in the treatment-failed group tended to be lower than that in the sustained virological response (SVR) group. The pretreatment serum 4βHC level in patients with treatment failure was significantly higher than that in patients with an SVR but in whom the prevalence of resistance-associated variants was low in the pretreatment setting. Conclusion The evaluation of CYP3A4 activity by measuring 4βHC before treatment may provide additional information that can potentially be used to select cost- and efficacy-optimized treatment of HCV.

Detection of Gut Dysbiosis due to Reduced Clostridium Subcluster XIVa Using the Fecal or Serum Bile Acid Profile

BACKGROUND

Dysbiosis, especially a reduced Clostridium subcluster XIVa (XIVa), has been reported in several gastrointestinal diseases. Since XIVa is thought to be the main bacterial cluster that metabolizes bile acids (BAs) in the human intestine, we hypothesized that the BA profile in feces, and possibly in serum, could be a convenient biomarker for intestinal XIVa activity.

METHODS

First, blood and feces were collected from 26 healthy controls and 20 patients with gastrointestinal diseases, and the relationships among fecal microbiomes and fecal and serum BA compositions were studied. Second, serum BA compositions of 30 healthy controls and the remission and exacerbation states of 14 Crohn's disease (CD) and 12 ulcerative colitis (UC) patients were compared. Fecal microbiomes were analyzed by terminal restriction fragment length polymorphism analysis, and BA compositions were quantified by HPLC-MS/MS.

RESULTS

The highest positive correlation was observed between the fecal XIVa proportion and fecal unconjugated deoxycholic acid (DCA)/(DCA+unconjugated cholic acid [CA]) (r = 0.77, P < 0.0001) or serum DCA/(DCA+CA) (r = 0.52, P < 0.001). Diurnal variation in serum XIVa candidate markers also showed that DCA/(DCA+CA) was most stable and not affected by the contraction of the gallbladder. Serum DCA/(DCA+CA) was not significantly different between remission and exacerbation states in either CD or UC patients, but was significantly reduced in those in the remission state of CD and the remission and exacerbation states of UC compared with healthy controls (P < 0.05).

CONCLUSIONS

Decreased XIVa exhibits a strong correlation with reduced intestinal BA metabolism. Fecal and serum DCA/(DCA+CA) could be useful surrogate markers for the intestinal proportion of XIVa.

Serum Amino Acid Profiling in Citrin-Deficient Children Exhibiting Normal Liver Function During the Apparently Healthy Period

BACKGROUND

Citrin (mitochondrial aspartate-glutamate transporter) deficiency causes the failures in both carbohydrate-energy metabolism and the urea cycle, and the alterations in the serum levels of several amino acids in the stages of newborn (NICCD) and adult (CTLN2). However, the clinical manifestations are resolved between the NICCD and CTLN2, but the reasons are still unclear. This study evaluated the serum amino acid profile in citrin-deficient children during the healthy stage.

METHODS

Using HPLC-MS/MS analysis, serum amino acids were evaluated among 20 citrin-deficient children aged 5-13 years exhibiting normal liver function and 35 age-matched healthy controls.

RESULTS

The alterations in serum amino acids characterized in the NICCD and CTLN2 stages were not observed in the citrin-deficient children. Amino acids involved in the urea cycle, including arginine, ornithine, citrulline, and aspartate, were comparable in the citrin-deficient children to the respective control levels, but serum urea was twofold higher, suggestive of a functional urea cycle. The blood sugar level was normal, but glucogenic amino acids and glutamine were significantly decreased in the citrin-deficient children compared to those in the controls. In addition, significant increases of ketogenic amino acids, branched-chain amino acids (BCAAs), a valine intermediate 3-hydroxyisobutyrate, and β-alanine were also found in the citrin-deficient children.

CONCLUSION

The profile of serum amino acids in the citrin-deficient children during the healthy stage showed different characteristics from the NICCD and CTLN2 stages, suggesting that the failures in both urea cycle function and energy metabolism might be compensated by amino acid metabolism.

SYNOPSIS

In the citrin-deficient children during the healthy stage, the characteristics of serum amino acids, including decrease of glucogenic amino acids, and increase of ketogenic amino acids, BCAAs, valine intermediate, and β-alanine, were found by comparison to the age-matched healthy control children, and it suggested that the characteristic alteration of serum amino acids may be resulted from compensation for energy metabolism and ammonia detoxification.

Effects of the Concomitant Use of Low-dose Clarithromycin with an Anti-TNFα Antibody in a Patient with Intestinal Behçet Disease

A 66-year-old Japanese male with a history of Behçet disease exhibited oral and genital ulcers, and a round deep ileocecal ulcer. He was treated with a combination of mesalazine and 20 mg/day of prednisolone (PSL), but was only partially responsive to PSL and we were not able to reduce the steroid dosage. Adalimumab was also administered. However, the ulcer was not completely responsive, and weaning the patient off PSL remained impossible. In contrast, additional treatment with clarithromycin completely healed the refractory active ulcer and left only a scar. Furthermore, the ulcer has since maintained the scar stage despite successfully weaning the patient from PSL.

Efficacy and safety of ombitasvir/paritaprevir/ritonavir in dialysis patients with genotype 1b chronic hepatitis C

AIM

From a pharmacokinetic viewpoint, the use of ombitasvir/paritaprevir/ritonavir, one of the standards of care for genotype 1b chronic hepatitis C in Japan, could be possible in patients with impaired renal function. The aim of this study was to assess the efficacy and safety of this combination that have not yet been addressed in patients undergoing dialysis.

METHODS

A retrospective, multicenter study evaluated the outcome of 12-week ombitasvir (non-structural protein [NS]5A inhibitor)/paritaprevir (NS3/4A protease inhibitor)/ritonavir combination therapy for dialysis patients. The primary end-point was sustained virologic response 12 weeks after therapy (SVR12).

RESULTS

The subjects were 31 patients with a median age of 64 years (range, 49-85 years), including 10 cirrhotic patients. All of the 31 patients had an estimated glomerular filtration rate level <15 mL/min/1.73 m² , defined as end-stage renal disease (ESRD). Pre-existing resistance-associated substitutions at position L31 and Y93 of the NS5A region were detected in 0% and 3.6% (1/28), respectively. The rates of rapid virologic response, end-of-treatment response, and SVR12 were 93.5% (29/31), 100% (31/31), and 96.8% (30/31), respectively. The incidence of adverse events was 35.5% (11/31). Of the 11 patients, one discontinued the treatment due to erythema multiforme and thereafter relapsed. The most frequent adverse event was pruritus (6.5%; 2/31).

CONCLUSIONS

The present study suggests that ombitasvir/paritaprevir/ritonavir combination therapy is effective and safe for genotype 1b chronic hepatitis C patients undergoing dialysis due to ESRD.

Modulation of Stimulator of Interferon Genes (STING) Expression by Interferon-γ in Human Keratinocytes

Infection of microbial pathogen triggers the innate immune system, and the induction of interferons (IFNs) play a vital role in host antiviral response. Stimulator of interferon genes (STING) was identified as a crucial regulator of the DNA sensing pathway, and activates both nuclear factor-κB and interferon regulatory factor 3 transcription pathways to evoke IFNs production. In this study, we studied the upregulation of STING mRNA expression, induced by IFN-γ in human keratinocytes (HaCaT). STING promoter assays clarified that a gamma-activated sequence (GAS), located at - 7 to - 15-bp, is required for IFN-γ-upregulated promoter activity. Furthermore, an electrophoretic mobility shift assay showed that signal transducers and activators of transcription 1 (STAT1) attach to the GAS motif on the human STING promoter region. This indicates that IFN-γ/Janus kinases/STAT1 signaling is essential for the STING upregulation in human keratinocytes.