In order to maintain and develop a universal health insurance system, it is crucial to utilize limited medical resources effectively. In this context, considerations are underway to introduce health technology assessments (HTAs), such as cost-effectiveness analyses (CEAs), into the medical treatment fee system. CEAs, which is the general term for these methods, are classified into four categories, such as cost-effectiveness analyses based on performance indicators, and in the comparison of health technologies, the incremental cost-effectiveness ratio (ICER) is also applied. When I comprehensively consider several Japanese studies based on these concepts, I find that, in the results of the analysis of the economic performance of healthcare systems, Japan shows the most promising trend in the world. In addition, there is research indicating the superior cost-effectiveness of Rituximab against refractory nephrotic syndrome, and it is expected that health economics will be actively applied to the valuation of technical innovations such as drug discovery.

IgG4-related disease (IgG4-RD) is an inflammatory condition characterized by a high serum IgG4 concentration and the abundant infiltration of lymphocytes and IgG4-positive plasma cells in the tissue, as well as spatial (diverse clinical manifestations) and temporal (the possibility of recurrence) multiplicities. Since the initial documentation of IgG4-related disease in patients with autoimmune pancreatitis in 2001, a growing body of evidence has been accumulating to suggest that various-virtually all-organs can be affected by IgG4-RD. In general, steroid therapy is effective and is considered to be the first-line treatment for IgG4-RD. The precise mechanism underlying this systemic disorder has remained unknown. Considering that IgG4-RD was specified as being an intractable disease in 2015, further studies are needed to clarify whether IgG4-RD is indeed a distinct disease entity or a complex of disorders of different etiologies and clinical conditions.

Objective The aim of the present study is to investigate the role of double-balloon enteroscopy in the diagnosis and surgical treatment of metastatic small bowel tumors.

Patients We retrospectively reviewed the records of 13 patients with metastatic small bowel tumors among 376 patients who underwent double-balloon enteroscopy from June 2005 to March 2017 in our hospital.

Results The primary lesion sites were the lung (n=9), kidney (n=2), stomach (n=1) and duodenum (n=1). The clinical presentations were anemia requiring blood transfusion (n=10), obstructive symptoms (n=2), and no symptoms (n=1). The locations of the metastatic small bowel tumors were the jejunum (n=7), ileum (n=1), and both sites (n=5). The histological diagnosis of the metastatic tumor was made from biopsy specimens taken with double-balloon enteroscopy from all 11 patients whose condition permitted a biopsy. In seven patients, the findings on double-balloon endoscopy were determinants of the kind and extent of surgical treatment performed. Four patients had multiple metastatic small bowel tumors, and all were able to be removed surgically with guidance from preoperative tattooing at double-balloon endoscopy. After operation, blood transfusions were no longer needed in four of six patients who had required preoperative transfusions for the treatment of anemia, and one patient with intestinal obstructive symptoms was able to resume oral intake.

Conclusion Double-balloon endoscopy was useful for making a histological diagnosis and directing surgical treatment in patients with metastatic small bowel tumors. Surgical treatment afforded palliation of symptoms in five patients.

Objective The pathogenesis of multiple white and flat elevated lesions in the stomach has not been elucidated. We investigated the prevalence of such lesions and their characteristics in affected individuals.

Methods The subjects were 1,995 individuals (1,320 men, 675 women; mean age 54.2±9.5 years) who visited our medical center for a comprehensive annual medical checkup and in whom the status of Helicobacter pylori infection could be determined. The presence of multiple white and flat elevated lesions in the stomach and the degree of gastric mucosal atrophy were evaluated using endoscopic findings.

Results Multiple white and elevated lesions in the stomach were observed in 60 subjects (3.0%), who were predominantly women and older in comparison to those without such lesions. The prevalence rates of these lesions in H. pylori-positive and H. pylori-negative and in post-eradicated subjects were 0.5%, 1.3%, and 4.6%, respectively. A multiple logistic regression analysis demonstrated that post-eradication status, female gender, older age, and a higher grade of gastric mucosal atrophy were significant risk factors for the occurrence of multiple white and elevated lesions.

Conclusion Multiple white and elevated lesions were frequently observed in subjects with successful H. pylori eradication.

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.

Objective To analyze the changes in the pharmacotherapy and glycemic control trends in elderly patients with type 2 diabetes mellitus (T2DM) in Japan.

Methods We extracted the data of 7,590 patients (5,396 men and 2,194 women; median year of birth: 1945) with T2DM registered in the National Center Diabetes Database for the years 2005 to 2013, and conducted age-stratified (<65, 65-74, and ≥75 years of age) analyses.

Results The hemoglobin A1c (HbA1c) levels declined from 2005 to 2013, and for those who received antihyperglycemic drug prescription, the HbA1c levels were lower in the older age group than in the younger age group. In the ≥75 age group, dipeptidyl peptidase-4 inhibitors (DPP4i) became the most frequently prescribed drug (49.1%) in 2013, and sulfonylureas remained the second-most frequently prescribed drug (37.8%) with decreased prescribed doses. The prescription ratio of oral drugs associated with a risk of hypoglycemia was higher in patients ≥75 years of age than in those <75 years of age (40.5% and 26.4%, respectively in 2013), although it showed a downward trend. The prescription rates of insulin for patients ≥75 years of age increased during the study period.

Conclusion The pharmacotherapy trends for elderly patients with T2DM changed dramatically in Japan with the launch of DPP4i in 2009. Glycemic control in a considerable portion of the ≥75 age group in Japan was maintained at the expense of potential hypoglycemia by the frequent, although cautious, use of sulfonylureas, glinides and insulin.

A 68-year-old man with a history of diabetes mellitus was admitted to our hospital with a diagnosis of acute pancreatitis. Abdominal computed tomography revealed a suspicious tumor in the body of the pancreas, along with a dilated main pancreatic duct and edema of the pancreatic tail. Endoscopic retrograde pancreatography was performed after treating the patient's pancreatitis. When a cannula tip was advanced beyond the stenosis, deep into the distal pancreatic duct, thick white pus was evacuated. A bacteriological examination of the aspirated pancreatic juice revealed Enterobacter cloacae, and a cytological examination revealed adenocarcinoma. The diagnosis was acute obstructive suppurative pancreatic ductitis associated with pancreatic carcinoma.

A 47-year-old Japanese man was referred to hospital after the detection of a liver tumor. Dynamic computed tomography and gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging were consistent with a diagnosis of hepatocellular carcinoma (HCC). No perfusion defect was observed in the post-vascular phase of contrast-enhanced ultrasound (CEUS). Histopathological staining of the tumor cells was positive for antibodies against HMB-45 and cluster of differentiation (CD) 68, confirming the diagnosis of hepatic angiomyolipoma (HAML). These findings indicated the presence of macrophages in HAML. We herein report a case of HAML explain how macrophages that are present within the tumor affect the staining characteristics in the post-vascular phase of CEUS.

We herein report the case of a 37-year-old man with both pheochromocytoma and visceral fat accumulation and describe the sequential changes in his adiponectin levels throughout the clinical course from catecholamine crisis until the follow-up for adrenalectomy. His adiponectin level decreased during catecholamine crisis and increased after adrenalectomy. However, his adiponectin level decreased again at two years postoperatively when his visceral fat area greatly increased. This case suggests that catecholamines and visceral fat volume may affect adiponectin metabolism in subjects with pheochromocytoma, which may precipitate cardiovascular complications in this endocrine disease.

Immune checkpoint inhibitors (ICIs) are becoming a common and important cancer therapy. ICIs are associated with a unique category of side effects, termed immune-related adverse events (irAEs). We herein report the case of a 72-year-old man with postoperative recurrence of lung squamous cell carcinoma who was treated with nivolumab and who developed proteinuria and a worsening kidney function. A kidney biopsy revealed IgA nephropathy. After drug withdrawal, the proteinuria improved and the deterioration of the patient's renal function was halted. Although renal irAEs are considered to be rare and glomerulonephritis is not typical presentation, physicians need to pay more attention to renal irAEs and glomerular injury.

Tacrolimus is the most commonly used immunosuppressant. Because of its narrow therapeutic range, it is necessary to frequently monitor its concentration. We report the case of a 25-year-old man who underwent kidney transplantation whose tacrolimus concentrations, as measured by an affinity column-mediated immunoassay, were falsely elevated. As we reduced the dose of tacrolimus, the recipient developed T cell-mediated rejection. Using the same blood samples, an enzyme-multiplied immunoassay technique showed that the patient's levels of tacrolimus were extremely low. A further examination indicated that the false increase in the tacrolimus concentration was likely due to an unknown interfering substance. We administered methylprednisolone and antithymocyte-globulin. The patient's serum creatinine level decreased and remained stable after these treatments.

We herein report a case of immune-related colitis induced by the long-term use of nivolumab. A 62-year-old Japanese man was treated with nivolumab at 3 mg/kg every 2 weeks for advanced lung adenocarcinoma. The patient was admitted to our hospital due to non-bloody watery diarrhea after the 70th dose of nivolumab. A biopsy specimen of the colon mucosa revealed evidence of colitis with cryptitis and crypt microabscesses. He was diagnosed with immune-related colitis and started on predonisolone 60 mg/day. Subsequently, his symptoms remarkably resolved. Consideration of immune-related adverse events up to several years after the initiation of nivolumab is important.

A 50-year-old man with lung adenocarcinoma (c-T1aN2M1b) experienced reddish purpura mainly on the lower legs after receiving 12 cycles of second-line chemotherapy with docetaxel. There was tumor enlargement on computed tomography performed to assess the therapeutic response, so paraneoplastic IgA vasculitis was considered. IgA vasculitis was diagnosed based on a biopsy of the skin lesion and histology of an upper gastrointestinal hemorrhagic mucosal erosion. As IgA vasculitis can lead to serious gastrointestinal or systemic complications, IgA vasculitis should be considered as a differential diagnosis for rashes in patients with malignancy.

A 63-year-old man with occupational exposure to silica presented with cutaneous ulcer, pleuritic pain, and a fever. Laboratory data showed lymphopenia and positive serum antinuclear and anti-DNA antibodies. Computed tomography of the chest showed egg shell-like calcification of the hilar and mediastinal lymph nodes without pulmonary parenchymal involvement of silicosis. A surgical biopsy showed silicotic nodules with surrounding infiltration of lymphocytes and plasma cells in the parietal pleura. With a diagnosis of systemic lupus erythematosus (SLE), systemic corticosteroid therapy was given, which led to the resolution of symptoms and laboratory abnormalities. We discuss the relationship between silica exposure and the development of SLE.

A 59-year-old woman suffering from dry cough and dyspnea was admitted to our hospital. She had undergone concurrent chemo-radiotherapy five months earlier. Chest computed tomography revealed bilateral ground-glass opacities extending outside the irradiated lung field. Her eosinophil numbers were increased in both the peripheral blood and the bronchoalveolar lavage fluid; therefore, she was diagnosed with radiation pneumonitis accompanied by eosinophilic alveolitis. Steroid therapy promptly improved the pneumonitis. Radiation pneumonitis accompanied by eosinophilic alveolitis extending outside the irradiated field is rare. Bronchoalveolar lavage is useful for a diagnosis, and steroid therapy is effective for treatment.

A 70-year-old woman with lymphadenopathy was admitted to hospital in 2008. Lymph node biopsy showed reactive lymphoid hyperplasia (RH) with monoclonal proliferation of Epstein-Barr virus (EBV). Her lymphadenopathy regressed without treatment. In 2014, the patient presented with nasal obstruction because of a left nasal mass. She was diagnosed with EBV-positive diffuse large B-cell lymphoma (DLBCL) of the elderly based on the examination of a biopsy specimen of the mass. The IgH rearrangement in the specimens from the 2008 and the 2014 revealed that they were genetically identical. This is the first report of RH progressing to DLBCL, and suggests that EBV-positive B-cells in RH lymph nodes predict the evolution to DLBCL.

TAFRO syndrome is a systemic inflammatory disorder that is characterized by thrombocytopenia, anasarca, myelofibrosis, renal dysfunction, and organomegaly. Although thrombocytopenia is one of the major features of TAFRO syndrome, complications of disseminated intravascular coagulation (DIC) are not common. The therapeutic strategy for TAFRO syndrome complicated by DIC has not been established. We herein describe a case of TAFRO syndrome with DIC that was successfully treated with tocilizumab (an anti-IL-6 receptor antibody) and recombinant thrombomodulin (rTM). This case suggests a possible therapeutic benefit of rTM in patients with TAFRO syndrome complicated by DIC.

A 73-year-old man with primary myelofibrosis (PMF) was being treated with hydroxyurea, which was changed to ruxolitinib treatment because of worsening constitutional symptoms. Although ruxolitinib rapidly induced relief, he developed a high-grade fever. A comprehensive fever work-up found no apparent cause of the fever, except for PMF. Therefore, we increased the dose of ruxolitinib and added prednisolone, which was gradually withdrawn with resolution of the fever. However, the patient subsequently developed disseminated tuberculosis and died eight months after initiation of ruxolitinib. Our case highlights the importance of assessing and monitoring the immune status of patients receiving ruxolitinib.

A previously healthy 58-year-old man was admitted for muscle pain and weakness [manual muscle testing (MMT) of 4/4 for upper and lower limbs]. We detected elevated levels of inflammatory makers and PR3-anti-neutrophil cytoplasmic antibody (ANCA). Subsequently, the muscle weakness rapidly progressed to an MMT of 2 for all limbs. Magnetic resonance imaging indicated muscle edema, and the creatine kinase (CK) level increased to 29,998 U/L. Methylprednisolone (mPSL) and cyclophosphamide pulse therapy improved the patient symptoms. MMT recovered to 4 for all limbs. A muscle biopsy showed degenerated muscle fibers surrounded by neutrophil-predominant infiltration. In addition, lamina elastic breakdown and fibrinoid necrosis of arterioles were observed. A final diagnosis of microscopic polyangiitis (MPA) limited to the muscles was made.

A 16-year-old boy who was a non-smoker presented with a prolonged severe dry cough and malaise of 3 months in duration. Despite an increase in the patient's inflammatory marker levels, no respiratory lesions were radiologically or serologically detected. We suspected that the cough reflex pathway had been stimulated by large vessel vasculitis (LVV, a non-respiratory inflammatory condition) and diagnosed the patient with Takayasu arteritis. While inflammation of either the ascending pharyngeal or pulmonary artery have been reported to cause cough in patients with LVV, the present case shows that intense inflammation of the aortic arch and the starting portion of its main branches may stimulate a vagus nerve branch as a novel mechanism causing cough.

A 74-year-old woman who exhibited drowsiness was referred to our hospital. Enhanced head magnetic resonance imaging (MRI) revealed multiple ring-enhancing lesions and lesions showing partial mild hemorrhaging. The patient gradually progressed to a comatose condition with notable brain deterioration of unknown cause on follow-up MRI. On day nine, the patient inexplicably died, although brain herniation was suspected. Autopsy and histopathology revealed numerous amoebic trophozoites in the perivascular spaces and within the necrotic tissue. Brain immunostaining tested positive for Balamuthia mandrillaris. Infection due to free-living amoeba is rare in Japan; however, it may increase in the near future due to unknown reasons.

Cavernous hemangioma is a rare, non-functional, benign adrenal tumor. Adrenal cavernous hemangioma is often diagnosed after surgery with a histologic examination. A 70-year-old man complaining of appetite loss was admitted to our hospital. An incidental large left adrenal mass was found by computed tomography (CT). There were no clinical signs of adrenogenital syndrome, Cushing's syndrome or primary aldosteronism. Total resection was carried out. The pathological diagnosis was cavernous hemangioma. The differentiation of adrenal tumor is necessary in cases of large tumors, and resection is desirable given the risks of hemorrhaging and rupture.