Immunoglobulin-like transcript 2 as an impaired anti-tumor cytotoxicity marker of natural killer cells in patients with hepatocellular carcinoma.

Introduction: Natural killer (NK) cells play a pivotal role in immune surveillance in the liver. We aimed to identify potential targets for NK cell-mediated immune intervention by revealing the functional molecules on NK cells in HCC patients. Methods: To evaluate the impact of aging on NK cell phenotypes, we examined NK cells from healthy volunteers (HVs) of various ages. Because ILT2 expression on CD56dim NK cells increased with increasing age, we enrolled age-matched HCC patients and HVs. We determined the NK cell phenotypes in blood mononuclear cells (PBMCs) and intrahepatic lymphocytes (IHLs) from cancerous and non-cancerous tissues. We evaluated cytotoxicity and antibody-dependent cellular cytotoxicity (ADCC) of NK cells in vitro. Results: ILT2-positive CD56dim NK cells in PBMCs were increased in HCC patients compared with HVs. In HCC patients, ILT2-positive CD56dim NK cells were increased in cancerous IHLs compared with non-cancerous IHLs and PBMCs. We examined the impact of macrophage migration inhibitory factor (MIF) on ILT2 expression in co-cultures of HCC cells and NK cells. The enhanced expression of ILT2 on CD56dim NK cells from HCC patients was inhibited by masking antibodies against MIF and CXCR4. ILT2-positive CD56dim NK cells exhibited lower capacities for cytotoxicity and ADCC than ILT2-negative cells, which were partially restored by ILT2 blockade. Conclusions: In HCC patients, ILT2 is a signature molecule for cancerous CD56dim NK cells with impaired cytolytic capacity. The MIF-CXCR4 interaction is associated with ILT2 induction on CD56dim NK cells and ILT2 serves as a target for functional NK cell restoration.

Vitamin D deficiency during the coronavirus disease 2019 (COVID-19) pandemic among healthcare workers.

BACKGROUND & AIMS: Vitamin D deficiency is a common nutritional problem worldwide that may have worsened during the coronavirus disease 2019 (COVID-19) pandemic. The present study sought to examine the prevalence and correlates of vitamin D deficiency among healthcare workers three years after the start of the COVID-19 pandemic. METHODS: Participants comprised 2543 staff members from a medical research institute, who completed a questionnaire and donated blood samples in June 2023. 25-hydroxyvitamin D (25[OH]D) levels were measured using an electrochemiluminescence immunoassay. Logistic regression was used to calculate the odds ratio and its 95% confidence interval while adjusting for covariates. RESULTS: The proportions of participants with vitamin D insufficiency (25[OH]D 20-29 ng/mL) and deficiency (25[OH]D < 20 ng/mL) were 44.9% and 45.9%, respectively. In a multivariable-adjusted model, factors associated with a higher prevalence of vitamin D deficiency included younger age, female sex, fewer hours of daytime outdoor physical activity during leisure time (without regular use of sunscreen), lower intake of fatty fish, no use of vitamin D supplements, smoking, and no alcohol consumption. Occupational factors, including shift work, were not independently associated with vitamin D deficiency. CONCLUSIONS: Our results suggest that vitamin D insufficiency and deficiency are highly prevalent among healthcare workers. Health education regarding lifestyle modifications for this occupational group are warranted to improve their vitamin D status in the COVID-19 era.

Preinfection Neutralizing Antibodies, Omicron BA.5 Breakthrough Infection, and Long COVID: A Propensity Score-Matched Analysis.

BACKGROUND: Data are limited on the role of preinfection humoral immunity protection against Omicron BA.5 infection and long coronavirus disease (COVID) development. METHODS: We conducted nested case-control analysis among tertiary hospital staff in Tokyo who donated blood samples in June 2022 (1 month before Omicron BA.5 wave), approximately 6 months after receiving a third dose of COVID-19 mRNA vaccine. We measured live virus-neutralizing antibody titers against wild type and Omicron BA.5, and anti-receptor-binding domain (RBD) antibody titers at preinfection, and compared them between cases and propensity-matched controls. Among the breakthrough cases, we examined association between preinfection antibody titers and incidence of long COVID. RESULTS: Preinfection anti-RBD and neutralizing antibody titers were lower in cases than controls. Neutralizing titers against wild type and Omicron BA.5 were 64% (95% confidence interval [CI], 42%-77%) and 72% (95% CI, 53%-83%) lower, respectively, in cases than controls. Individuals with previous Omicron BA.1/BA.2 infections were more frequent among controls than cases (10.3% vs 0.8%), and their Omicron BA.5 neutralizing titers were 12.8-fold higher than infection-naive individuals. Among cases, preinfection antibody titers were not associated with incidence of long COVID. CONCLUSIONS: Preinfection immunogenicity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may play a role in protecting against the Omicron BA.5 infection but not preventing long COVID.

Durability and determinants of anti-SARS-CoV-2 spike antibodies following the second and third doses of mRNA COVID-19 vaccine.

OBJECTIVES: To examine the differences in durability and its determinants of humoral immunity following 2- and 3-dose COVID-19 vaccination. METHODS: Throughout the pandemic, we evaluated the anti-spike IgG antibody titers of 2- and 3-dose mRNA vaccine recipients over time among the staff of a medical and research center in Tokyo. Linear mixed models were used to estimate trajectories of antibody titers from 14 to 180 days after the last immune-conferred event (vaccination or infection) and compare antibody waning rates across prior infection and vaccination status, and across background factors in infection-naïve participants. RESULTS: A total of 6901 measurements from 2964 participants (median age, 35 years; 30% male) were analyzed. Antibody waning rate (percentage per 30 days [95% CI]) was slower after 3 doses (25% [23-26]) than 2 doses (36% [35-37]). Participants with hybrid immunity (vaccination and infection) had further slower waning rates: 2-dose plus infection (16% [9-22]); 3-dose plus infection (21% [17-25]). Older age, male sex, obesity, coexisting diseases, immunosuppressant use, smoking, and alcohol drinking were associated with lower antibody titers, whereas these associations disappeared after 3 doses, except for sex (lower in female participants) and immunosuppressant use. Antibody waned slightly faster in older participants, females, and alcohol drinkers after 2 doses, whereas it did not differ after 3 doses across except sex. DISCUSSION: The 3-dose mRNA vaccine conferred higher durable antibody titers, and previous infection modestly enhanced its durability. The antibody levels at a given time point and waning speed after 2 doses differed across background factors; however, these differences mostly diminished after 3 doses.

Cumulative and undiagnosed SARS-CoV-2 infection among the staff of a medical research centre in Tokyo after the emergence of variants.

To describe the trend of cumulative incidence of coronavirus disease 19 (COVID-19) and undiagnosed cases over the pandemic through the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants among healthcare workers in Tokyo, we analysed data of repeated serological surveys and in-house COVID-19 registry among the staff of National Center for Global Health and Medicine. Participants were asked to donate venous blood and complete a survey questionnaire about COVID-19 diagnosis and vaccine. Positive serology was defined as being positive on Roche or Abbott assay against SARS-CoV-2 nucleocapsid protein, and cumulative infection was defined as either being seropositive or having a history of COVID-19. Cumulative infection has increased from 2.0% in June 2021 (pre-Delta) to 5.3% in December 2021 (post-Delta). After the emergence of the Omicron, it has increased substantially during 2022 (16.9% in June and 39.0% in December). As of December 2022, 30% of those who were infected in the past were not aware of their infection. Results indicate that SARS-CoV-2 infection has rapidly expanded during the Omicron-variant epidemic among healthcare workers in Tokyo and that a sizable number of infections were undiagnosed.

Neutralizing antibodies after three doses of the BNT162b2 vaccine, breakthrough infection, and symptoms during the Omicron-predominant wave.

OBJECTIVES: To investigate the role of immunogenicity after the third vaccine dose against Omicron infection and COVID-19-compatible symptoms of infection. METHODS: First, we examined vaccine effectiveness (VE) of the third dose against the second dose during the Omicron wave among the staff at a tertiary hospital in Tokyo. In a case-control study of third vaccine recipients, we compared the preinfection live-virus neutralizing antibodies (NAb) against Omicron between breakthrough cases and their controls who had close contact with patients with COVID-19. Among these cases, we examined the association between NAb levels and the number of COVID-19-compatible symptoms. RESULTS: Among the 1456 participants for VE analysis, 60 breakthrough infections occurred during the Omicron wave. The third dose VE for infection was 54.6%. Among the third dose recipients, NAb levels against Omicron did not differ between the cases (n = 22) and controls (n = 21). Among the cases, those who experienced COVID-19-compatible symptoms had lower NAb levels against Omicron than those who did not. CONCLUSION: The third vaccine dose was effective in decreasing the risk of SARS-CoV-2 infection during Omicron wave compared with the second dose. Among third dose recipients, higher preinfection NAb levels may not be associated with a lower risk of Omicron infection. Contrarily, they may be associated with fewer symptoms of infection.

Coronavirus Disease 2019 (COVID-19) Breakthrough Infection and Post-Vaccination Neutralizing Antibodies Among Healthcare Workers in a Referral Hospital in Tokyo: A Case-Control Matching Study.

BACKGROUND: While increasing coverage of effective vaccines against coronavirus disease 2019 (COVID-19), emergent variants raise concerns about breakthrough infection. Data are limited, however, whether breakthrough infection during the epidemic of the variant is ascribed to insufficient vaccine-induced immunogenicity. METHODS: We describe incident COVID-19 in relation to the vaccination program among workers of a referral hospital in Tokyo. During the predominantly Delta epidemic, we followed 2415 fully vaccinated staff (BNT162b2) for breakthrough infection and selected 3 matched controls. We measured post-vaccination neutralizing antibodies against the wild-type, Alpha (B.1.1.7), and Delta (B.1.617.2) strains using live viruses and anti-spike antibodies using quantitative assays, and compared them using the generalized estimating equation model between the 2 groups. RESULTS: No COVID-19 cases occurred 1-2 months after the vaccination program during the fourth epidemic wave in Japan, dominated by the Alpha variant, while 22 cases emerged 2-4 months after the vaccination program during the fifth wave, dominated by the Delta variant. In the vaccinated cohort, all 17 cases of breakthrough infection were mild or asymptomatic and participants had returned to work early. There was no measurable difference between cases and controls in post-vaccination neutralizing antibody titers against the wild-type, Alpha, Delta, and anti-spike antibody titers, while neutralizing titers against the variants were considerably lower than those against the wild-type. CONCLUSIONS: Post-vaccination neutralizing antibody titers were not decreased among patients with breakthrough infection relative to their controls under the Delta variant outbreak. The result points to the importance of infection-control measures in the post-vaccination era, irrespective of immunogenicity profile.

Cessation of methotrexate and a small intestinal resection provide a good clinical course for a patient with a jejunum perforation induced by a methotrexate-associated lymphoproliferative disorder: a case report.

BACKGROUND: Methotrexate (MTX) is a frequently used drug in the treatment of rheumatoid arthritis (RA), but occurrences of lymphoproliferative disorders (LPD) have been reported in patients undergoing an MTX regimen. Almost half of the patients with methotrexate-associated lymphoproliferative disorders (MTX-LPD) have extranodal lesions; moreover, although extremely rare, digestive tract perforations resulting from the extranodal lesions of MTX-LPD have also been reported. CASE PRESENTATION: We describe the case of an 81-year-old woman with RA who had been prescribed MTX at 6 mg per week for the past 11 years. She was admitted to our hospital with occasional abdominal pain and was first diagnosed with enteritis. Her abdominal pain did not improve, and a computed tomography scan showed abdominal effusion and free air in the abdominal cavity. She was diagnosed with a digestive tract perforation and underwent emergency surgery. The perforation site was identified in the jejunum, and she underwent small intestinal resection around the perforated region. The pathological findings showed an ulcer in the jejunum and infiltration of large atypical lymphocytes around the perforated region. An immunohistochemical examination revealed the expression of a cluster of differentiation 20 and latent membrane protein 1. Considering the patient's history of RA treated with MTX, she was diagnosed as having Epstein-Barr virus (EBV)-related MTX-LPD with a histological diagnosis of EBVMCU. MTX was discontinued after the surgery, and her soluble interleukin-2 receptor (sIL-2R) levels had returned to normal 1 year later. She has had a good course for the 2 years since surgery and remains asymptomatic with no recurrence of MTX-LPD, as confirmed by the sIL-2R levels. CONCLUSION: We experienced a rare case of the jejunum perforation induced by MTX-LPD. Since only a few cases have been reported of a patient with small intestinal perforation induced by MTX-LPD, further research is necessary to evaluate the clinicopathological features of MTX-LPD. The patient had disease remission after surgery and by discontinuing MTX treatment; our case did not require chemotherapy. EBV-positive patients, especially those with a pathological presentation of EBVMCU, could have a higher likelihood of remission, which could have been a factor in the present case.

Clear cell neuroendocrine tumor in the gallbladder diagnosed as a benign polyp preoperatively: a case report.

BACKGROUND: Gallbladder neuroendocrine neoplasm is a rare disease that is divided into neuroendocrine tumors (NETs) and neuroendocrine carcinomas (NECs). Clear cell NETs of the gallbladder are extremely rare. We report the case of a patient with polypoid clear cell NET G1 of the gallbladder who underwent laparoscopic cholecystectomy. CASE PRESENTATION: A 10-mm pedunculated polyp in the gallbladder neck was detected on a follow-up abdominal ultrasound in a 60-year-old man with chronic hepatitis and hepatitis B without medication. Six months later, an abdominal ultrasound revealed that the tumor had enlarged to 12 mm in size. He was asymptomatic and had no abnormalities in other laboratory examinations, including the tumor markers, carcinoembryonic antigen and CA19-9. Abdominal ultrasound showed a 12-mm polyp in the neck of the gallbladder with perfusion and focal thickening of the gallbladder wall. A gallbladder stone was also seen in the fundus. An enhanced computed tomography scan and magnetic resonance imaging revealed a polypoid lesion and gallbladder stone located at the neck of the gallbladder and the fundus, respectively. Malignancy could not be excluded, and hence, a laparoscopic cholecystectomy was performed. Pathologically, a pedunculated polyp (14 × 11 × 15 mm) was observed in the neck of the gallbladder, and the polypoid lesion comprised nests or trabecular growths of clear NET cells in the lamina propria (ENETS: T1N0M0; AJCC: T1aN0M0). Immunohistochemical staining with synaptophysin, chromogranin A, and CD56 was confined to the tumor. The pathological diagnosis was clear cell NET G1 of the gallbladder. Although clear cell NET is often described as a distinct manifestation of von Hippel-Lindau disease (VHL), the patient had no past medical or family history of VHL. Until his one-and-a-half-year follow-up, the patient was doing well and without any signs of recurrence. CONCLUSION: We report an extremely rare case of gallbladder clear cell NET G1. When NET G1 is incidentally identified in a gallbladder surgical specimen, clinical information and pathological findings should be considered as references.

A Multicenter Phase 2 Trial to Evaluate the Efficacy of mFOLFOX6 + Cetuximab as Induction Chemotherapy to Achieve R0 Surgical Resection for Advanced Colorectal Liver Metastases (NEXTO Trial).

BACKGROUND: The effect of cetuximab plus mFOLFOX on downsizing of the tumors for curative resection has yet to be assessed for patients with advanced colorectal liver metastases (CRLMs). This study aimed to assess the oncologic benefit of cetuximab plus mFOLFOX for wild-type KRAS patients with advanced CRLMs. METHODS: In this multicenter phase 2 trial, patients with technically unresectable tumor and/or five or more CRLMs harboring wild-type KRAS were treated with mFOLFOX plus cetuximab. The patients were assessed for resectability after 4 treatments, and then every 2 months up to 12 treatments. Patients with resectable disease were offered surgery after a waiting period of 1 month. The primary end point of the study was the R0 resection rate. The secondary end points were safety, progression-free survival (PFS), and overall survival (OS). The study is registered with the University Hospital Medical Information Network-Clinical Trials Registry Clinical Trials Registry (no. C000007923). RESULTS: Between 2012 and 2015, 50 patients from 13 centers were enrolled in this trial. Two patients were excluded because they had not received induction therapy. The 48 patients had a complete response rate of 0% and a partial response rate of 64.6%. For 26 R0 resections (54.2%) and 5 R1 resections (10.4%), no mortality occurred. During a median follow-up period of 31 months, the median OS for all the patients was calculated to be 41 months (95% confidence interval, 28-not reached). The 3-year OS rate was 59%. CONCLUSION: For patients with advanced CRLMs harboring wild-type KRAS, cetuximab administered in combination with mFOLFOX yields high response rates, leading to significantly high R0 resection rates and favorable prognoses.

Bone morphogenetic protein 4 provides cancer-supportive phenotypes to liver fibroblasts in patients with hepatocellular carcinoma.

BACKGROUND: Cancer-associated fibroblasts (CAFs) are essential constituents of cancer-supportive microenvironments. The high incidence of hepatocellular carcinoma (HCC) in advanced fibrosis patients implies that fibroblasts have a promoting effect on HCC development. We aimed to explore the regulators of phenotypes and function of CAFs in the liver. METHODS: We established primary cancer-associated fibroblasts (CAFs) and non-cancerous liver fibroblasts (NFs) from 15 patients who underwent HCC resection. We compared phenotypes, capacity of cytokine/chemokine production and gene expression profiles between pairs of CAFs and NFs from the same donors. We examined resected tissue from additional 50 patients with HCC for immunohistochemical analyses. RESULTS: The CAFs expressed more ACTA2 and COL1A1 than the NFs, suggesting that CAFs are more activated phenotype. The CAFs produced larger amounts of IL-6, IL-8 and CCL2 than the NFs, which led to invasiveness of HuH7 in vitro. We found that Bone Morphogenetic Protein-4 (BMP4) is up-regulated in CAFs compared to NFs. The CAF phenotype and function were gained by BMP4 over-expression or recombinant BMP4 given to fibroblasts, all of which decreased with BMP4 knockdown. In tissues obtained from the patients, BMP4-positive cells are mainly observed in encapsulated fibrous lesions and HCC. Positive expression of BMP4 in HCC in resected tissues, not in fibroblasts, was associated with poorer postoperative overall survival in patients with HCC. CONCLUSION: Endogenous and exogenous BMP4 activate liver fibroblasts to gain capacity of secreting cytokines and enhancing invasiveness of cancer cells in the liver. BMP4 is one of the regulatory factors of CAFs functioning in the microenvironment of HCC.

A case of intraductal papillary mucinous neoplasm with high serum pepsinogen II level.

We report the case of a 65-year-old woman who had a high level of serum pepsinogen II. Several months earlier, she had found a mass on the right side of her upper abdomen. Esophagogastroduodenoscopy did not reveal atrophic or inflammatory findings. She had not taken proton pump inhibitors, and there was no indication of renal dysfunction. Imaging tests showed a mass of approximately 80mm in the pancreatic head. We performed pancreatoduodenectomy, and the histopathological examination revealed an intraductal papillary mucinous neoplasm (IPMN) of gastric type. Serum pepsinogen II levels substantially lowered after surgery. To the best of our knowledge, this is the first report on a relationship between IPMN and serum pepsinogen II.

[Primary adenosquamous carcinoma of the liver presenting with hematochezia due to tumor invasion of the colon].

A 69-year-old female was referred to our hospital with hematochezia. Dynamic computed tomography demonstrated a large tumor with rim enhancement and central necrosis that invaded into the transverse colon. The tumor was resected, and histopathological examination revealed mixed adenocarcinoma and squamous cell carcinoma with partial abscess formation. On the basis of a literature review and the findings from the present case, rim enhancement with central necrosis on imaging appears to be characteristic of this disease.

Surgery for digestive malignancies in patients with psychiatric disorders.

BACKGROUND: The psychiatric population has been reported to be accompanied with a higher morbidity and mortality in several situations. However, little is known about the effect of co-morbid psychiatric disorders on surgical risk during major digestive surgery for malignancies. Our purpose in the present study, therefore, was to evaluate the impact of co-morbid psychiatric disorders on the outcome of surgery for digestive malignancies. METHODS: We retrospectively reviewed medical records of 568 consecutive patients who underwent hepatectomies, gastrectomies, or colorectal resections between June 1998 and May 2006. Of these, 86 patients had psychiatric disorders (disorder group: DG) and the remaining 482 patients did not (non-disorder group: NG). Postoperative parameters including morbidity, mortality, length of postoperative hospital stay in the surgical ward, and the incidence of psychiatric disorder-associated problems were assessed. RESULTS: Overall, there was 1 patient who died within 30 days in hospital in the DG and 2 patient deaths in the NG. Thirty complications developed in 24 patients of the DG, whereas 138 complications developed in 129 patients of the NG. There was no significant difference in the morbidity or mortality rate between the two groups. The length of the postoperative hospital stay was also similar between the two groups, and the incidence of psychiatric disorder-associated postoperative problems was about ten times higher in the DG than in the NG. CONCLUSIONS: Patients with psychiatric disorders are not accompanied with excess surgical risk during major surgery for digestive malignancies as compared to patients without psychiatric disorders.