In 2022, cases of pediatric acute hepatitis of unknown origin increased in the United Kingdom. Initially, with the relaxation of Coronavirus disease 2019 measures, adenovirus's prevalence was noted. Moreover, metagenomic analysis suggested that adeno-associated virus type 2 (AAV2) was the causative agent; high levels of AAV2 were detected in many affected children. HLA-DRB1*04:01 was also detected, indicating a possible genetic predisposition. Acute liver failure sometimes occurs with gene therapy using intravenous infusion with AAV9 vectors, which might be a related condition. Some cases of hepatitis are also caused by sever acute respiratory syndrome coronavirus 2. In Japan, postpandemic pediatric hepatitis cases have not increased compared to prepandemic cases, and AAV2 has rarely been detected-differing from the reports and results from the United Kingdom and United States. Historically, approximately 40% of pediatric acute liver failure cases have an unknown origin, and AAV is presumed to be involved in some of these cases.

Although quality control is critical in clinical research to ensure reliable data collection, few observational studies have a data quality control system. To improve the quality of a multicenter observational study including patients with hepatitis C virus-associated cirrhotic receiving antiviral therapy, we assigned a quality control officer to the study office to examine query content. A total of 369 patients were enrolled from 2019 to 2021, and data collection management was conducted by the Research Electronic Data Capture system, with regular entry promotion and data checks. The 847 queries that occurred between 2020 and 2021 were categorized into "not entered" (617 queries) and "data-related" (230 queries), and all queries were resolved. The semi-annual changes in query content showed a decreasing trend for "not entered" (212/179/133/93), while "data-related" remained (34/54/86/56). Our findings demonstrated that the assignment of a quality control officer could enhance data quality, leading to improved quality of observational studies.

Owing to the coronavirus disease 2019 (COVID-19) pandemic that was reported and spread from Bukan, China at the end of 2019, transplant medicine faced various challenges, including COVID-19 infection of recipients, transmission of infection through human traffic for transplantation, and the risk of COVID-19 infection of transplant patients. Therefore, a comparison of the number of organ donations and deceased donor liver transplant cases between 2019, before the COVID-19 pandemic, and after 2020, after the pandemic, was performed.

Here, the authors describe a case of acute liver failure during the COVID-19 pandemic, wherein deceased donor liver transplantation was performed at the appropriate time through collaboration among multiple disciplines and institutions from the early stage of diagnosis.

A woman in her 50s underwent hepatectomy for type B cirrhosis and hepatocellular carcinoma. Approximately 15 months postoperatively, she developed anemia, decreased white blood cell count, and peripheral neuropathy. Her blood test showed low serum copper and high serum zinc levels, and it was determined that the patient had copper deficiency due to excess zinc, which was caused by the long-term zinc intake that was prescribed by another department postoperatively. In addition to drug discontinuation, copper supplementation with pure cocoa was administered; subsequently, blood cell counts recovered, and peripheral neuropathy improved. Although zinc replacement therapy is becoming common in patients with cirrhosis, zinc can induce copper deficiency if continuously taken in large doses. Hemopenia due to copper deficiency is frequently difficult to distinguish, and neuropathy may be irreversible. The need to measure serum copper during zinc administration should be communicated.

A 60-year-old man was diagnosed with hepatocellular carcinoma (HCC) and received chemotherapy with atezolizumab plus bevacizumab. After two courses, computed tomography (CT) revealed an improvement in HCC treatment. Five months after initiating chemotherapy, nasal hemorrhage occurred and was associated with bevacizumab, which required nasal mucosa ablation twice. Atezolizumab monotherapy was administered, but after two courses CT results revealed exacerbation. The dose of bevacizumab was reduced to 7.5 mg/kg. After seven courses, CT showed improvement of HCC and disappearance of one metastatic lung tumor.

Based on the findings of the IMbrave150 trial, atezolizumab+bevacizumab (atezo+beva) combination therapy is currently used as a first-line treatment for unresectable hepatocellular carcinoma (HCC) in Japan. Although atezo+beva combination therapy has proved to be useful in clinical practice, reports of immune-related adverse events (irAEs) associated with immune checkpoint inhibitors are increasing. Herein, we present three cases with pituitary adrenocortical insufficiency that occurred following atezo+beva therapy for unresectable HCC. We diagnosed pituitary adrenocortical insufficiency based on decreased serum cortisol levels and unchanged serum adrenocorticotropic hormone levels. Notably, all patients experienced a considerable improvement in hyponatremia, and their blood pressure promptly normalized with the initiation of hydrocortisone treatment. Immune checkpoint inhibitors can cause various irAEs. Of these, hyponatremia and hypotension occurred due to pituitary adrenocortical insufficiency should be kept in mind, when administering atezo+beva as part of the treatment regimen.