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Background: Patients with inflammatory bowel diseases (IBD) can develop extraintestinal manifestations (EIMs) during the disease course, which sometimes impact their quality of life. Objectives: This study aimed to clarify the prevalence and types of EIMs using a hospital-based IBD cohort in Japan. Methods: A patient cohort with IBD was established in 2019, as participated by 15 hospitals in Chiba Prefecture of Japan. Using this cohort, the prevalence and types of EIMs, which are defined based on previous reports and the Japanese guidelines, were investigated. Results: This cohort enrolled 728 patients, including 542 ulcerative colitis (UC) and 186 Crohn’s disease (CD). Of these patients with IBD, 10.0% were identified with one or more EIMs (57 (10.5%) with UC and 16 (8.6%) with CD). Arthropathy and arthritis were the most common EIM in 23 (4.2%) patients with UC, followed by primary sclerosing cholangitis (PSC) (2.6%). Arthropathy and arthritis were also the most common in patients with CD, but no cases of PSC were observed. EIMs were more frequently observed in patients with IBD treated by specialists than in those treated by non-specialists (12.7% vs. 5.5%, p = 0.011). The incidence of EIMs in patients with IBD was not significantly different over time. Conclusions: The prevalence and types of EIMs in our hospital-based cohort in Japan did not significantly differ from those reported in previous or Western studies. However, the incidence might be underestimated due to the limited ability of non-IBD specialists to discover and describe EIMs in patients with IBD.

Monoclonal immunoglobulin (MIg)-associated glomerular diseases with non-organized deposits are rare disorders. They have recently been categorized into light chain deposit disease (LCDD), light and heavy chain deposit disease (LHCDD), heavy chain deposit disease (HCDD), proliferative glomerulonephritis with MIg deposits (PGNMID) and its light chain only variant (PGNMID-LC), and membranous glomerulopathy with light chain-restricted deposits (MG-LC). In our Japanese cohort of more than 9,500 patients who underwent renal biopsy (1979 - 2020), we evaluated clinicopathological features and long-term outcomes in 38 patients with MIg-associated glomerular diseases with non-organized deposits: LCDD (n = 9), LHCDD (n = 8), HCDD (n = 5), PGNMID-membranoproliferative glomerulonephritis (MPGN) (n = 7), PGNMID-LC (n = 2), and MG-LC (n = 7). In patients with LCDD, a low estimated glomerular filtration rate (eGFR) at biopsy, a high detection rate of urinary MIgs, a high incidence rate of multiple myeloma, and sever tubulointerstitial and vascular lesions were significant clinicopathological characteristics. Median duration of follow-up in each group was 42 - 114 months. Most patients were treated with steroid-based therapy. Patients with LCDD, LHCDD, HCDD, and MG-LC were recently treated with bortezomib-based therapy. Renal survival rate was significantly shorter for LCDD than of PGNMID and MG-LC. Patient survival rate was significantly longer for MG-LC than HCDD and PGNMID. Major causes of death were pulmonary and cardiovascular complications. Among disease groups, significant differences were observed in eGFR at biopsy, detection rates of urinary MIgs, incidence rates of multiple myeloma, severities of tubulointerstitial and vascular lesions, and long-term outcomes.

Background IgA nephropathy (IgAN) and IgA vasculitis with nephritis (IgAVN) are related glomerular diseases characterized by marked similarities in immunological and histological findings. We herein performed a comparative proteomic analysis of glomerular proteins in IgAN and IgAVN. Methods We used renal biopsy specimens from 6 IgAN patients without nephrotic syndrome (NS) (IgAN-I subgroup), 6 IgAN patients with NS (IgAN-II subgroup), 6 IgAVN patients with 0–8.0% of glomeruli with crescent formation (IgAVN-I subgroup), 6 IgAVN patients with 21.2–44.8% of glomeruli with crescent formation (IgAVN-II subgroup), 9 IgAVN patients without NS (IgAVN-III subgroup), 3 IgAVN patients with NS (IgAN-IV subgroup), and 5 control cases. Proteins were extracted from laser microdissected glomeruli and analyzed using mass spectrometry. The relative abundance of proteins was compared between groups. An immunohistochemical validation study was also performed. Results More than 850 proteins with high confidence were identified. A principal component analysis revealed a clear separation between IgAN and IgAVN patients and control cases. In further analyses, 546 proteins that were matched with ≥ 2 peptides were selected. The levels of immunoglobulins (IgA, IgG, and IgM), complements (C3, C4A, C5, and C9), complement factor H-related proteins (CFHR) 1 and 5, vitronectin, fibrinogen chains, and transforming growth factor-β inducible gene-h3 were higher (> 2.6 fold) in the IgAN and IgAVN subgroups than in the control group, whereas hornerin levels were lower ( Conclusions The present results suggest shared molecular mechanisms for glomerular injury in IgAN and IgAVN, except for enhanced glomerular complement activation in IgAN. Differences in the protein abundance of podocyte-associated and GBM proteins between IgAN and IgAVN patients with and without NS may be associated with the severity of proteinuria.

Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) involves multiple organs, including the lungs and central nervous system. Lung lesions are frequently reported as mass lesions or non-specific interstitial pneumonia, whereas organising pneumonia (OP) due to IgG4-RD is rare. Furthermore, limited information is currently available on hypertrophic pachymeningitis (HP). We herein report a case of IgG4-RD complicated with OP and HP. The diagnosis was confirmed based on the serum concentration of IgG4 and the results of salivary gland and transbronchial lung biopsies. HP did not respond to steroid monotherapy and was also resistant to rituximab and intravenous cyclophosphamide; however, the combination therapy of methotrexate and dexamethasone was effective.

Objectives The aim of this article is to evaluate the effectiveness and safety of rituximab (RTX) for microscopic polyangiitis and granulomatosis with polyangiitis in Japan. Methods In this prospective observational study, all patients with microscopic polyangiitis and granulomatosis with polyangiitis administered RTX were enrolled at each institution. During the observation period of 2 years, data up to 6 months were analysed. Cox proportional hazards analysis was used to assess the factors associated with an outcome. Results Of the 75 patients who received RTX for remission induction therapy, 53 achieved remission by the sixth month and 50 were in remission at the sixth month. During therapy, 38 serious adverse events were observed in 24 patients, 21 serious infections in 16 patients, and 9 patients died. No factors were associated with remission; however, there was a significant difference between patients with and without remission in serious adverse events (22.6% vs. 54.5%), serious infections (11.3% vs. 45.4%), and death (1.9% vs. 36.4%). The hazard ratio (95% confidence interval) for serious infection was 3.49 (1.29–9.74) for patients aged ≥ 75 years and 3.53 (1.31–9.53) for pulmonary complications. Four patients maintained remission for 6 months. Conclusions The effectiveness and safety of RTX for microscopic polyangiitis and granulomatosis with polyangiitis for up to 6 months was demonstrated.

To evaluate effectiveness and safety of rituximab (RTX) for microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA) in Japan.In this prospective observational study, all patients with MPA and GPA administered RTX were enrolled at each institution. During observation period of two years, data up to six months was analysed. Cox proportional hazards analysis was used to assess the factors associated with an outcome.Of the 75 patients who received RTX for remission induction therapy, 53 achieved remission by 6th month and 50 were in remission at 6th month. During therapy, 38 serious adverse events (SAE) were observed in 24 patients, 21 serious infections (SI) in 16 patients, and nine patients died. No factors were associated with remission; however, there was a significant difference between patients with and without remission in SAE (22.6 vs. 54.5 %), SI (11.3 vs. 45.4 %), and death (1.9 vs. 36.4 %). The hazard ratio (95 % CI) for SI was 3.49 (1.29-9.74) for patients aged ≥ 75 years and 3.53 (1.31-9.53) for pulmonary complications. Four patients maintained remission for 6 months.Effectiveness and safety of RTX for MPA and GPA for up to 6 months was demonstrated.

Arteriovenous malformation (AVM) of the small bowel is a rare disease and can be sometimes difficult to treat due to the diagnostic difficulty. We herein report a case of small intestinal bleeding of AVM successfully treated with double-balloon enteroscopy (DBE) and laparoscope-assisted resection. A 44-year-old man complained of hematochezia and visited the previous doctor. He underwent gastroscopy and colonoscopy, but no bleeding site was detected. However, he rebled 2 days later and became hypotensive. Abdominal computed tomography revealed a hypervascular nodule in the jejunum. He was transferred to our institution for further treatment. DBE was performed and revealed a small pulsatile lesion with a tiny mucosal break. We then injected a marking tattoo. Two days later, he underwent an operation. We were able to easily locate the tattooed lesion laparoscopically and performed jejunal partial resection. His postoperative course was uneventful. DBE enabled a precise diagnosis and minimal invasive surgery.

An improved process for preparing tenuifolin (presenegenin 3-β-d-glucopyranoside) from the root of Polygala senega L. was developed. A crude saponin mixture extracted from P. senega was subjected to hydrolysis, and the reactivity of compounds in the extract was controlled by utilizing the combination of a flow reactor and experimental design. In addition, column chromatography with HP 20, a synthetic polystyrenic adsorbent, allowed the gram-scale preparation of tenuifolin in a continuous manner with fewer steps. This approach shortens the total time required for gram-scale preparation from 16 to 5 h in a continuous manner while improving the yield from 0.59% to 2.08% (w/w).

Background Neutrophil extracellular traps (NETs) are critically involved in microscopic polyangiitis (MPA) pathogenesis, and some patients with MPA possess anti-NET antibody (ANETA). Anti-myosin light chain 6 (MYL6) antibody is an ANETA that affects NETs. This study aimed to determine the significance of anti-MYL6 antibody in MPA. Methods The influence of anti-MYL6 antibody on NET formation and actin rearrangement necessary for NET formation was assessed by fluorescent staining. An enzyme-linked immunosorbent assay was established to detect serum anti-MYL6 antibody, and the prevalence of this antibody in MPA was determined. Furthermore, the disease activity and response to remission-induction therapy of MPA were compared between anti-MYL6 antibody-positive and -negative MPA patients. Results Anti-MYL6 antibody disrupted G-actin polymerization into F-actin, suppressing phorbol 12-myristate 13-acetate-induced NET formation. Serum anti-MYL6 antibody was detected in 7 of 59 patients with MPA. The Birmingham vasculitis activity score (BVAS) of anti-MYL6 antibody-positive MPA patients was significantly lower than anti-MYL6 antibody-negative MPA patients. Among the nine BVAS evaluation items, the cutaneous, cardiovascular, and nervous system scores of anti-MYL6 antibody-positive MPA patients were significantly lower than anti-MYL6 antibody-negative MPA patients, although other items, including renal and chest scores, were equivalent between the two groups. The proportion of patients with remission 6 months after initiation of remission-induction therapy in anti-MYL6 antibody-positive MPA patients was significantly higher than in anti-MYL6 antibody-negative MPA patients. Conclusions Collective findings suggested that anti-MYL6 antibody disrupted actin rearrangement necessary for NET formation and could reduce the disease activity of MPA.

Atraumatic splenic rupture (ASR) is a rare but fatal complication of malignant lymphoma. However, only one case of intravascular large B-cell lymphoma (IVLBCL)-related ASR (IVLBCL-ASR) has previously been reported, and the mechanism of IVLBCL-ASR is unknown. We present the case of a 78-year-old man who died unexpectedly and was diagnosed with IVLBCL-ASR pathologically by autopsy. A massive intraperitoneal hemorrhage and four lacerations on the splenic surface were discovered during the autopsy. CD20-positive lymphoma cells that infiltrated into small vessels were highly concentrated in the center of the spleen and were only slightly distributed in the lacerations on the splenic surface. Therefore, increased intrasplenic pressure due to lymphoma cell proliferation was identified as the cause of ASR. The patient had undergone

Diagnosis of acute onset autoimmune hepatitis (A-AIH) has been difficult in that patients may not have typical clinicopathological features of AIH. In our previous reports of severe and fulminant AIH, two-thirds of them showed radiological heterogeneity: hepatic heterogeneous hypoattenuation on unenhanced computed tomography (CT) reflecting heterogeneous distribution of massive hepatic necrosis (severe centrilobular necrosis), which would be beneficial for the diagnosis. In the present study, we analyzed non-severe A-AIH patients with or without radiological heterogeneity and tried to find novel clinical features for supporting the early diagnosis.Clinical, biochemical, immunological, radiological and histological features of 42 patients with non-severe A-AIH at community hospitals between 2010 and 2020 were analyzed.Of 42, 28 patients on whom CT scans were performed and who could be fully analyzed were enrolled. Five patients showed hepatic heterogeneous hypoattenuation on unenhanced CT. There was no significant difference in clinical, biochemical, immunological and histological features at diagnosis between the two groups according to the presence of radiological heterogeneity, although mean minimum prothrombin time activity during the course was lower in patients with heterogeneity without statistical significance (p = 0.080). All responded to treatment well and achieved initial remission within 3 months.It is possible that patients with non-severe A-AIH show radiological heterogeneity reflecting centrilobular necrosis which is one of important diagnostic features of A-AIH. Accordingly, radiological heterogeneity might be beneficial for the diagnosis of A-AIH in combination with conventional clinicopathological features if it is detected in the absence of features suggestive of other liver diseases.

A 28-year-old woman exhibited a spiking fever, arthritis, and liver disfunction when she was 22 weeks pregnant. She was diagnosed with adult-onset Still's disease (AOSD). As her condition was resistant to corticosteroid therapy, tocilizumab (TCZ) was selected. The TCZ treatment was effective, and she delivered a healthy child while receiving TCZ treatment. Cases in which AOSD first arises during pregnancy are rare, and there have been no reports of TCZ treatment for AOSD being initiated during pregnancy. Although the safety of TCZ treatment during pregnancy has not been established, it may be effective against severe AOSD that develops during pregnancy.

l‐Lysine oxidase (LysOX) is a FAD‐dependent homodimeric enzyme that catalyzes the oxidative deamination of l‐lysine to produce α‐keto‐ε‐aminocaproate with ammonia and hydrogen peroxide. LysOX shows strict substrate specificity for l‐lysine, whereas most l‐amino acid oxidases (LAAOs) exhibit broad substrate specificity for l‐amino acids. Previous studies of LysOX showed that overall structural similarity to the well‐studied snake venom LAAOs. However, the molecular mechanism of strict specificity for l‐lysine was still unclear. We here determined the structure of LysOX in complex with l‐lysine at 1.7 Å resolution. The structure revealed that the hydrogen bonding network formed by D212, D315, and A440 with two water molecules is responsible for the recognition of the side chain amino group. In addition, a narrow hole formed by five hydrophobic residues in the active site contributes to strict substrate specificity. Mutation studies demonstrated that D212 and D315 are essential for l‐lysine recognition, and the D212A/D315A double mutant LysOX showed different substrate specificity from LysOX. Moreover, the structural basis of the substrate specificity change has also been revealed by the structural analysis of the mutant variant and its substrate complexes. These results clearly explain the molecular mechanism of the strict specificity of LysOX and suggest that LysOX is a potential candidate for a template to design LAAOs specific to other l‐amino acids.

Objective: To gain better understanding of the effects of biologics, we evaluated clinical outcomes in patients with moderate to severe exacerbations of ulcerative colitis (UC).Methods: This retrospective, multicenter study retrieved the entire clinical courses of UC patients who began treatments between 2004 and 2018. All exacerbations and clinical parameters, including treatment details for exacerbations and both remission and re-exacerbation dates, were identified during the observation period. Two different endpoints, the cumulative incidence rates of surgical resection and re-exacerbation, were evaluated separately in moderate to severe exacerbation events.Results: Among 1401 patients, 1626 exacerbation events were determined according to a partial Mayo score (remission: 7). During the observation period, as administration rates of biologics increased, both surgical resection and hospitalization rates decreased, for 959 moderate to severe exacerbation events. We confirmed that biologics significantly reduced the cumulative re-exacerbation rate in moderate to severe exacerbation events during the study period compared with suboptimal therapies (a 0.507-fold decrease risk according to COX regression analysis, P P = 0.606).Conclusions: Biologics may improve remission duration, but these agents had no significant impact in reducing the risk of surgical resection in moderate to severe active UC.

[Background:] Tertiary lymphoid tissues (TLTs) are ectopic lymphoid tissues found in chronically inflamed organs. Although studies have documented TLT formation in transplanted kidneys, the clinical relevance of these TLTs remains controversial. We examined the impacts of TLTs on future graft function using our histological TLT maturity stages and the association between TLTs and Banff pathologic scores. We also analyzed the risk factors for the development of TLTs. [Methods:] Serial protocol biopsy samples (0-hour, 1-, 6-, and 12-months) without rejection were retrospectively analyzed from 214 patients who underwent living donor kidney transplantation. TLTs were defined as lymphocyte aggregates with signs of proliferation and their stages were determined by the absence (stage I) or presence (stage II) of follicular dendritic cells. [Results:] Only 4% of patients exhibited TLTs at the 0-hour biopsy. Prevalence increased to almost 50% at the 1-month biopsy and then slightly further for 12 months. The proportion of advanced stage II TLTs increased gradually, reaching 19% at the 12-month biopsy. Presence of stage II TLTs was associated with higher risk of renal function decline after transplantation compared to patients with no TLT or stage I TLTs. Stage II TLTs were associated with more severe tubulitis and interstitial fibrosis/tubular atrophy at 12 months and predicted poorer graft function independently from the degree of interstitial inflammation. Pre-transplantation rituximab treatment dramatically attenuated the development of stage II TLTs. [Conclusions:] TLTs are commonly found in clinically stable transplanted kidneys. Advanced stage II TLTs are associated with progressive graft dysfunction, independent of interstitial inflammation., 移植腎の三次リンパ組織は腎予後と関連することを解明. 京都大学プレスリリース. 2021-11-02.

A 72-year-old man presented with a 6-month history of systemic edema. Hyperpigmentation, hemangioma, pleural effusion, IgG-kappa-type monoclonal protein, high vascular endothelial growth factor values, renal failure, and nerve conduction study abnormalities were also present. Multiparameter flow cytometry (MFC) showed 0.2% neoplastic plasma cells (CD38-, CD56-, and kappa-positive; CD19-, CD27-, and lambda-negative) in the bone marrow leading to POEMS syndrome. Cases involving kappa-type POEMS syndrome are extremely rare. A kidney biopsy revealed membranous proliferative glomerulonephritis-like changes in our case. Lenalidomide-dexamethasone therapy improved the renal function. Detection of neoplastic plasma cells by MFC was useful for the accurate diagnosis and treatment evaluation.

In Japan, a novel coronavirus has been prevalent since January 2020. The Japanese and local governments have implemented various measures, including declaring a state of emergency, according to the epidemic situation in each region. This study estimated the effective reproduction number (Rt) using the number of confirmed positive cases and positivity rates in Tokyo and examined the association between Rt and the rate of increase/decrease in the number of people across 12 sites. In Tokyo, there were five waves in which Rt was persistently estimated as approximately 1.0. The fourth and fifth waves started under the declaration of the state of emergency and coincided with an increase in the number of people. However, the contribution of the number of people to Rt was inconsistent, even when the number of people was of the same magnitude. A possible reason for this is difference in the countermeasures content, as the impact of vaccination was considered to be minor at the time. Where vaccination is insufficient, the wave is terminated by controlling the number of people leaving their homes. It is suggested that infection could be controlled more efficiently, depending on the content of the countermeasures.

The infliximab biosimilar CT-P13 was the first biosimilar drug targeting tumor necrosis factor-α. However, its efficacy and safety in real-world clinical situations have remained insufficient. Therefore, we aimed to verify the efficacy and safety of CT-P13 in bio-naïve patients with Crohn’s disease. This retrospective multicenter study compared the remission rate at week 54 between patients with Crohn’s disease treated with originator infliximab or CT-P13. Endoscopic and laboratory findings were assessed in both groups. A total of 184 (156 originator and 28 CT-P13) patients were analyzed. Of these, 138 originator users and 19 biosimilar users completed 54-week administration. The clinical remission rates in patients taking originator infliximab of CT-P13 at week 54 were 92.5% and 100%, respectively. The endoscopic scores of each group significantly decreased from baseline at week 54 in both groups, and the mucosal healing rate at week 54 was 53% and 64%, respectively. Laboratory data significantly improved from baseline to week 14 and 54 in both groups. Adverse events were observed more frequently in the CT-P13 group ( 25% vs. 4.5%, p = 0.0015). The efficacy of CT-P13 were comparable with those of originator infliximab in bio-naïve patients with Crohn’s disease evaluated by clinical, endoscopic, and laboratory findings.

We determined the usefulness and prognostic ability of the renal risk score (RRS), proposed in Europe, for Japanese patients with antineutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis (AAGN) and high myeloperoxidase (MPO)-ANCA positivity; these aspects remain to be verified.This retrospective study was conducted on 86 Japanese patients with new, biopsy-confirmed AAGN. We calculated the RRS and analyzed the relationship between this classification, and clinicopathological features and prognosis. We also compared the predictive values between RRS for endpoints including renal death and conventional prognostic tools for patients with AAGN.There were 33, 37, and 16 patients in the low-, medium-, and high-risk groups, respectively. All patients were MPO-ANCA positive. The median follow-up period was 33 months; 16 (18.6%) patients progressed to end-stage renal disease (ESRD). In the high-risk group, 9/16 (56.3%) patients progressed to ESRD, and renal prognosis was significantly poorer than that in other groups (low-risk group, P 0.001; medium-risk group, P = 0.004). In Cox multivariate regression analysis, RRS was an independent, poor renal prognostic factor (hazard ratio 5.22; 95% confidence interval 2.20-12.40; P 0.001). The receiver-operating characteristic curves of the RRS for each endpoint were comparable with those of the 2010 histological classification and those of the severity classification of Japanese rapidly progressive glomerulonephritis.This is the first study to report the usefulness of the RRS for predicting renal outcomes among Japanese patients with AAGN. Our predictive value of the RRS was comparable with that of conventional prognostic tools.

Graphical abstract, Highlights • The suppression mechanism of activity by propeptide remains unclear for most LAAOs. • The crystal structures of the LysOX precursor (prLysOX) have been determined. • The propeptide indirectly changes the active site structure to suppress the activity. • prLysOX can adopt another conformation similar to mature LysOX. • prLysOX is able to be activated without proteolytic processing., Harmuful proteins are usually synthesized as inactive precursors and are activated by proteolytic processing. l-Amino acid oxidase (LAAO) is a flavoenzyme that catalyzes the oxidative deamination of l-amino acid to produce a 2-oxo acid with ammonia and highly toxic hydrogen peroxide and, therefore, is expressed as a precursor. The LAAO precursor shows significant variation in size and the cleavage pattern for activation. However, the molecular mechanism of how the propeptide suppresses the enzyme activity remains unclear except for deaminating/decarboxylating Pseudomonasl-phenylalanine oxidase (PAO), which has a short N-terminal propeptide composed of 14 residues. Here we show the inactivation mechanism of the l-lysine oxidase (LysOX) precursor (prLysOX), which has a long N-terminal propeptide composed of 77 residues, based on the crystal structure at 1.97 Å resolution. The propeptide of prLysOX indirectly changes the active site structure to inhibit the enzyme activity. prLysOX retains weak enzymatic activity with strict specificity for l-lysine and shows raised activity in acidic conditions. The structures of prLysOX crystals that soaked in a solution with various concentrations of l-lysine have revealed that prLysOX can adopt two conformations; one is the inhibitory form, and the other is very similar to mature LysOX. The propeptide region of the latter form is disordered, and l-lysine is bound to the latter form. These results indicate that prLysOX uses a different strategy from PAO to suppress the enzyme activity and suggest that prLysOX can be activated quickly in response to the environmental change without proteolytic processing.

There is yet no gold standard for the diagnosis of acute-onset autoimmune hepatitis (A-AIH), especially histologically acute AIH. As a result, long-term observation of A-AIH has been difficult and the nature is not well known. We retrospectively analyzed the clinicopathological features of A-AIH over a long prospective follow-up period. Clinical, biochemical, immunological and pathological features of 30 patients (21 female, mean age 55.1 ± 13.1 years) with non-severe A-AIH “without signs of clinical and radiological chronicity” admitted to a community hospital between 2001 and 2015 who were prospectively followed for more than 2 years were analyzed retrospectively. Liver histology of 45% showed acute and 55% chronic hepatitis. Mean age was older, prothrombin time activity was higher, AIH scores before treatment were lower in histologically acute hepatitis than histologically chronic hepatitis significantly. Liver fibrosis was not coarse, but delicate with severe activity in most patients showing chronic hepatitis defined by our strict criteria. Median (range) follow-up period was 6.9 (2.1–16.2) years. Six (20%) patients experienced episode of relapses. All were alive at the last follow-up point. Corticosteroid was continued at 2.5–5 mg/day until the study end point without serious side effects in most patients. Serial change of alanine aminotransferase levels, immunoglobulin G levels and anti-nuclear antibody titers did not show statistical difference between histologically acute and chronic hepatitis. Rapid progression of fibrosis could occur in A-AIH. Treatment response and long-term prognosis were good, and not different between patients with histologically acute and chronic hepatitis.