Single-cell RNA sequencing of intestinal immune cells in neonatal necrotizing enterocolitis.

PURPOSE: Necrotizing enterocolitis (NEC) causes fatal intestinal necrosis in neonates, but its etiology is unknown. We analyzed the intestinal immune response to NEC. METHODS: Using single-cell RNA sequencing (scRNA-seq), we analyzed the gene expression profiles of intestinal immune cells from four neonates with intestinal perforation (two with NEC and two without NEC). Target mononuclear cells were extracted from the lamina propria of the resected intestines. RESULTS: In all four cases, major immune cells, such as T cells (15.1-47.7%), B cells (3.1-19.0%), monocytes (16.5-31.2%), macrophages (1.6-17.4%), dendritic cells (2.4-12.2%), and natural killer cells (7.5-12.8%), were present in similar proportions to those in the neonatal cord blood. Gene set enrichment analysis showed that the MTOR, TNF-α, and MYC signaling pathways were enriched in T cells of the NEC patients, suggesting upregulated immune responses related to inflammation and cell proliferation. In addition, all four cases exhibited a bias toward cell-mediated inflammation, based on the predominance of T helper 1 cells. CONCLUSION: Intestinal immunity in NEC subjects exhibited stronger inflammatory responses compared to non-NEC subjects. Further scRNA-seq and cellular analysis may improve our understanding of the pathogenesis of NEC.

Laparoscopic definitive surgery for choledochal cyst is performed safely and effectively in infants.

Background: Laparoscopic definitive surgery for choledochal cyst (CC) in infants requires advanced skills because of their small size. If patients with a prenatal diagnosis of CC have any biliary symptoms, they need semi-emergency definitive surgery. This study aimed to estimate whether laparoscopic definitive surgery for CC can be performed safely and effectively in infants, especially when emergency surgery is required. Patients and Methods: From January 2006 to December 2019, 21 patients under 1 year of age underwent laparoscopically or open definitive surgery, and 16 patients aged 3-5 years underwent laparoscopic surgery for CC at our institution. In cases of prenatal diagnosis, elective surgery (EL) was performed at about 6 months of age for patients with no biliary symptoms; the semi-emergency surgery (EM) was performed when patients had any biliary symptoms. Surgical outcomes were retrospectively compared between the Lap <1 y and Op <1 y groups and between the Lap <1 y and Lap 3-5 y groups. In addition, the surgical outcomes of those who underwent EM were also evaluated. Results: Operative time was significantly longer, and blood loss was significantly lower in the Lap <1 y group than in the Op <1 y group. All surgical outcomes were similar between the Lap <1 y and Lap 3-5 y groups and between the EM and EL groups. Conclusion: Laparoscopic definitive surgery for CC in infants under 1 year of age is safe and feasible. Even semi-emergency laparoscopic surgery can be performed safely and effectively in small infants.

Risk factors and outcomes of bile leak after laparoscopic surgery for congenital biliary dilatation.

PURPOSE: One of the main causes of stricture at hepaticojejunostomy site after surgery for congenital biliary dilatation is inflammation or infection associated with bile leak. The aim of this study was to determine the risk factors and outcomes of bile leak after laparoscopic surgery. METHODS: We retrospectively reviewed the demographics and outcomes of patients who underwent laparoscopic surgery for congenital biliary dilatation between September 2013 and December 2019. Data from patients with bile leak were compared to data from patients without bile leak. RESULTS: Fourteen of 78 patients had bile leak. Hepatic duct diameter at anastomosis was the only risk factor of bile leak. Patients with the diameter ≤ 10 mm had higher incidence of bile leak than in patients with the diameter > 10 mm (P = 0.0023). Among them, bile leak occurred more frequently in patients operated on by non-qualified surgeons based on the Japan Society for Endoscopic Surgery endoscopic surgical skill qualification system than by qualified surgeons (P = 0.027). However, none of the patients with bile leak developed anastomotic stricture afterwards. CONCLUSION: Although good technical skill is necessary to avoid bile leak in narrow hepatic duct cases (≤ 10 mm), slight bile leak may not result in anastomotic stricture.

Drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms severity score: A useful tool for assessing disease severity and predicting fatal cytomegalovirus disease.

BACKGROUND: The prognosis of drug-induced hypersensitivity syndrome (DiHS)/drug reaction with eosinophilia and systemic symptoms (DRESS) is highly unpredictable. Severe complications, either related or unrelated to cytomegalovirus (CMV) reactivation, are a highly probable cause of death. OBJECTIVES: The aim was to establish a scoring system for DiHS/DRESS that can be used to monitor severity, predict prognosis, and stratify the risk of developing CMV disease and complications. METHODS: A retrospective analysis of 55 patients with DiHS/DRESS was performed. A composite score was created using clinical data. DiHS/DRESS patients were also stratified into 3 groups based on the scores to predict the risk of CMV reactivation and complications. RESULTS: This scoring system made it possible to predict CMV disease and complications. Scores ≥4 were associated with the later development of CMV disease and complications, while no patients with scores <4 developed complications. LIMITATIONS: This was a single-institution study with a relatively small patient cohort that lacked a validation cohort. CONCLUSIONS: Our scoring system may be useful for predicting CMV-related complications, and early intervention with anti-CMV agents should be considered in patients with scores ≥4 or with evidence of CMV reactivation.

Monocytes are involved in the balance between regulatory T cells and Th17 cells in severe drug eruptions.

BACKGROUND: Drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms (DiHS/DRESS) is a distinct phenotype of severe drug eruptions characterized by sequential reactivations of herpesviruses. Although a progressive loss of suppressive function in regulatory T cells (Tregs) occurred during the course of DiHS/DRESS, but not in Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN), no previous studies investigated the mechanism. Given the recent finding that Treg development could be differentially regulated by CD16+ patrolling monocytes (pMOs) and CD14+ classical monocytes (cMOs), we can hypothesize that a differential fine-tuned interaction between Tregs and monocytes is the driving force behind the possible shift from Tregs to Th17 cells over a prolonged period of time in DiHS/DRESS. OBJECTIVE: To investigate whether the shift from Treg to Th17 could specifically occur during the course of DiHS/DRESS and to elucidate which subsets of monocytes could be involved in the shift. METHODS: We performed a prospective longitudinal study on the frequencies of Tregs, Th17 cells and monocyte subsets after onset of DiHS/DRESS and SJS/TEN, and long after their clinical resolutions. We next examined whether pMOs and cMOs could have a strong impact on the Th17/Treg differentiation and which cytokines could be crucial for the interaction between Th17/Tregs and MO subsets, by in vitro cocultures. RESULTS: Selective depletion of pMOs occurring at the acute stage of DiHS/DRESS was associated with the relative increase in the frequencies of cMOs producing IL-10 and it did drive Treg expansions. After clinical resolution, pMOs producing IL-6 were alternatively recruited and contributed to the eventual shift from a Treg to Th17 responses. CONCLUSIONS AND CLINICAL RELEVANCE: The gradual shift from Treg to Th17 cell development observed during the clinical course of DiHS/DRESS is mediated by the predominance of cMOs at the acute stage and alternatively recruited pMOs at the resolution stage, respectively.

Characteristics and outcomes of minimally invasive surgery for congenital biliary dilatation in children aged <6 years: Comparison between children and adults.

BACKGROUND/PURPOSE: We evaluated the minimally invasive surgery for congenital biliary dilatation (CBD) in adults and children and analyzed the surgical outcomes, especially in children aged <6 years. METHODS: Characteristics and surgical outcomes of patients with CBD who underwent minimally invasive surgery at our hospital between 2013 and 2023 were retrospectively reviewed. RESULTS: Overall, 129 patients (89 children aged <6 years, 9 children aged between 6 and 18 years, and 21 adults) were included in this study. Children exhibited more protein plug presence and abnormal biochemical data than adults. Incidence of postoperative pancreatic fistulas was highest in the adult group (3.4%, 11%, and 33%, respectively, p < .01). In children aged <6 years, postoperative bile leakage and pancreatic fistulas occurred in 9.0% and 3.4% of patients, respectively. Multivariate logistic regression analysis revealed that the Todani IVA was associated with a decrease in postoperative bile leakage (odds ratio: -1.7; 95% confidence interval: (-3.3)-(-0.22), p = .03). CONCLUSION: Adults with CBD required prolonged operative times and had more short-term complications than children with CBD. In children aged <6 years, minimally invasive surgery for CBD can be safely performed; however, a small diameter of the bile duct may be associated with bile leakage.

Duodenal duplication cyst at the second part of the duodenum with congenital duodenal position anomaly completely resected by laparoscopic partial duodenectomy: a case report.

BACKGROUND: Duodenal duplication cysts (DDC) are rare duplications of the alimentary tract. Their treatment depends on their size and location. A radical treatment is total resection, if possible. However, partial excision, puncture, and marsupialization can be selected to prevent surgical injury to the pancreaticobiliary tract despite the risk of recurrence. There are some reports of pancreaticoduodenectomy for DDC because of the risk of recurrent symptoms and malignancy. However, this is considered excessively invasive for DDC, particularly in pediatric cases, because of its extremely low rate of malignancy and high morbidity and mortality rates. We encountered a case of DDC with a congenital duodenal position anomaly occurring in the second part of the duodenum. Taking advantage of the congenital duodenal position anomaly, the DDC was completely resected without injuring the pancreaticobiliary duct. CASE PRESENTATION: A 6-year-old boy was diagnosed with a duodenal duplication cyst with obstruction. There was a congenital duodenal position anomaly. The distal second part of the duodenum was the dorsal side of the proximal second part of the duodenum and ascended upward from the proximal second part of the duodenum. The third and fourth parts of the duodenum ran downward to the left and posterior parts of the portal vein, forming the ligament of Treitz. Complete laparoscopic resection of the duodenal duplication cyst and the second to fourth parts of the duodenum, and duodenojejunostomy with retrocolic reconstruction was performed because the duodenum was easily mobilized to the ligament of Treitz owing to the duodenal position anomaly. The duodenojejunostomy with retrocolic reconstruction achieved a more physiologically normal appearance compared to what would have been achieved with a Roux-en-Y reconstruction. The patient was discharged on postoperative day 12 without any complications. CONCLUSIONS: The procedure used in this case might not be easily applied in all laparoscopy cases. However, it could be an option for duodenal duplication cysts with congenital duodenal position anomalies.

Developing an Effective Off-the-job Training Model and an Automated Evaluation System for Thoracoscopic Esophageal Atresia Surgery.

BACKGROUND: Pediatric minimally invasive surgery requires advanced technical skills. Off-the-job training (OJT), especially when using disease-specific models, is an effective method of acquiring surgical skills. To achieve effective OJT, it is necessary to provide objective and appropriate skill assessment feedback to trainees. We aimed to construct a system that automatically evaluates surgical skills based on forceps movement using deep learning (DL). METHODS: Using our original esophageal atresia OJT model, participants were tasked with performing esophageal anastomosis. All tasks were recorded for image analysis. Based on manual objective skill assessments, each participant's surgical skills were categorized into two groups: good and poor. The motion of the forceps in both groups was used as training data. Employing this training data, we constructed an automated system that recognized the movement of forceps and determined the quality of the surgical technique. RESULTS: Thirteen participants were assigned to the good skill group and 32 to the poor skill group. These cases were validated using an automated skill assessment system. This system showed a precision of 75%, a specificity of 94%, and an area under the receiver operating characteristic curve of 0.81. CONCLUSIONS: We constructed a system that automatically evaluated the quality of surgical techniques based on the movement of forceps using DL. Artificial intelligence diagnostics further revealed the procedures important for suture manipulation. LEVELS OF EVIDENCE: Level IV.

Short- and long-term outcomes of 34 patients with drug-induced hypersensitivity syndrome in a single institution.

BACKGROUND: Drug-induced hypersensitivity syndrome (DIHS)/drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe systemic hypersensitivity reaction caused by specific drugs, in which herpesvirus reactivations and organ dysfunction occur during the course of the disease. Although recent reports have documented the development of autoimmune disease after complete resolution of DIHS/DRESS, relatively little is known about long-term outcomes after complete resolution of the disease. OBJECTIVE: The aim of this study was to retrospectively analyze complications and sequelae in the early and late phases of DIHS/DRESS according to treatment. METHODS: In all, 34 patients were classified into 2 groups: 14 patients with oral corticosteroid treatment; and 20 with noncorticosteroid treatment. The disease time course was divided into 2 periods: the first 6 months after onset of the drug reaction (early phase); and the period thereafter (late phase). Investigations to detect the presence of viral/bacterial infectious diseases, organ dysfunction, and autoantibodies were performed in both early and late phases. RESULTS: Herpesvirus infections and pneumonia were detected in 6 and 2 patients, respectively, in the corticosteroid treatment group in the early phase. In the noncorticosteroid treatment group, 2 patients developed autoimmune diseases, namely lupus erythematosus and autoimmune thyroiditis. Autoantibodies were detected in 44.4% of patients examined in the late phase of the disease. LIMITATIONS: This study only evaluated a small number of autoantibodies. CONCLUSION: The need for anti-inflammatory effects from systemic corticosteroids should be balanced with the risk of infectious diseases and the benefits of preventing the appearance of later autoimmune conditions in patients with DIHS/DRESS.

Defective regulatory T cells in patients with severe drug eruptions: timing of the dysfunction is associated with the pathological phenotype and outcome.

Toxic epidermal necrolysis (TEN) and drug-induced hypersensitivity syndrome (DIHS) represent two ends of a spectrum of severe drug eruptions: DIHS is unique in that severe epidermal damage seen in TEN is absent, sequential reactivations of herpesviruses occur, and autoimmunity often ensues. To investigate whether changes in regulatory T (Treg) cell function would contribute to variability in the clinical manifestations, we examined the frequency, phenotype, and function of Treg cells both during the acute stage and again long after clinical resolution of both diseases. Dramatic expansions of functional Treg cells were found in the acute stage of DIHS. In contrast, Treg function was profoundly impaired in TEN, although present in normal frequency. Skin homing addressins were more preferentially expressed on Treg cells in DIHS than in TEN. Indeed, Treg cells were more abundantly present in the skin lesions of DIHS. Surprisingly, Treg cells contracted upon resolution of DIHS became functionally deficient, whereas their functional defects in TEN were restored upon recovery. These findings indicate that a transitory impairment in their function during the acute stage of TEN may be related to severe epidermal damage, while a gradual loss of their function after resolution of DIHS may increase the risk of subsequently developing autoimmune disease.

Relationship between cytomegalovirus reactivation and dermatomyositis.

Dermatomyositis (DM) is an autoimmune disease manifested by muscle weakness and characteristic cutaneous eruptions. Cytomegalovirus (CMV) belongs to the ß-herpesvirinae subfamily of herpesviridae that cause morbidity and mortality in immunocompromised patients. With respect to the relationship between CMV and DM, it remains unknown whether CMV plays a pathogenetic role or whether CMV disease is an opportunistic infection due to immunosuppressive treatment. We report two patients with DM who developed cutaneous CMV ulcers within one month after the initiation of systemic corticosteroid treatment. In this context, we retrospectively studied the clinical characteristics of six DM patients with CMV reactivation and the effect of corticosteroid treatment on CMV reactivation in these patients. We also examined possible predictive parameters of CMV reactivation during the course of DM. Our results suggest that CMV reactivation occurs more frequently in DM patients than previously recognized; CMV reactivation occurs regardless of the dosage and duration of corticosteroid administration or the presence of underlying disease. Furthermore, our study shows that a reduction in platelets, serum globulin and IgG levels during the course of DM may be useful predictive parameters for CMV reactivation in patients with DM.

＜Editors' Choice＞ Long-term outcomes of the partial splenectomy for hypersplenism after portoenterostomy of patients with biliary atresia.

Massive splenomegaly and hypersplenism in patients with biliary atresia after Kasai portoenterostomy were treated with partial splenic embolization or total splenectomy. We performed partial splenectomy to reduce the complications of partial splenic embolization and avoid overwhelming post-splenectomy infection. This study aimed to evaluate the long-term effects of partial splenectomy for hypersplenism on postoperative liver and spleen function in patients with biliary atresia. Among jaundice-free patients with biliary atresia who underwent Kasai portoenterostomy between January 1992 and December 2012, 15 underwent partial splenectomy for massive splenomegaly and hypersplenism at our institution. Changes in the laboratory data 10 years post partial splenectomy were retrospectively investigated, and these along with the latest data were measured. A total of four patients (27%) required living-donor liver transplantation after partial splenectomy, a proportion similar to those who did not undergo partial splenectomy. Compared to the preoperative baseline, the platelet counts were significantly higher at 1 and 3 years after surgery (p < 0.05). Aspartic aminotransferase-to-platelet ratio index was significantly lower at 1, 7, and 10 years after partial splenectomy (p < 0.05). No further surgeries were required for hypersplenism after partial splenectomy over 10 years, and there were no cases of overwhelming post-splenectomy infection after partial splenectomy. Partial splenectomy is safe and effective for the treatment of hypersplenism with biliary atresia over a long time period. It could be considered as an alternative to partial splenic embolization as it can suppress hypersplenism for a long time and induces fewer postoperative complications.

Lichen planus occurring after influenza vaccination: report of three cases and review of the literature.

Although influenza vaccine is thought to be effective and safe, it occasionally causes systemic reactions such as toxic epidermal necrolysis, bullous pemphigoid, lichen planus (LP), etc. The period of increased risk of developing these events was different depending on the immune responses induced by the vaccination. We report 3 cases of LP which appeared after an influenza vaccination. Our cases indicate that the period of increased risk of developing vaccine-related LP was concentrated within 2 weeks after vaccination, and that the vaccine alone represents a triggering factor necessary for immune alteration sufficient for the development of LP. Because these adverse events tend to develop over a predictable time course, the time of onset may give an important clue to the diagnosis of vaccine-related diseases. We suggest that a history of recent vaccination should be sought in all patients presenting with linear LP.

Recognition of immune reconstitution syndrome necessary for better management of patients with severe drug eruptions and those under immunosuppressive therapy.

The immune reconstitution syndrome (IRS) is an increasingly recognized disease concept and is observed with a broad-spectrum of immunosuppressive therapy-related opportunistic infectious diseases and severe drug eruptions complicated by viral reactivations. Clinical illness consistent with IRS includes tuberculosis, herpes zoster, herpes simples, cytomegalovirus infections and sarcoidosis: thus, the manifestations of this syndrome and diverse and depend on the tissue burden of the preexisting infectious agents during the immunosuppressive state, the nature of the immune system being restored, and underlying diseases of the hosts. Although IRS has originally been reported to occur in the setting of HIV infection, it has become clear that the development of IRS can also be in HIV-negative hosts receiving immunosuppressive agents, such as prednisolone and tumor necrosis factor α inhibitors, upon their reduction and withdrawal. Drug-induced hypersensitivity syndrome, a life-threatening multiorgan system reaction, is another manifestation of the newly observed IRS. Clinical recognition of the IRS is especially important in improving the outcome for diseases with an otherwise life-threatening progenosis. Clinicians should be aware of the implications of IRS and recognize that relieving the symptoms and signs of immune recovery by anti-inflammatory therapies needs to be balanced with anti-microbial therapies aiming at reducing the amplitude and duration of tissue burden of preexisting microbes.

Pathomechanisms of lichen planus autoimmunity elicited by cross-reactive T cells.

Lichen planus (LP) is an idiopathic inflammatory disease of the skin and mucous membranes, characterized by an autoimmune attack on the epidermis by skin-infiltrating T cells. It remains unknown, however, how such autoaggressive T cells could be activated in vivo to cause epidermal damage; we hypothesize that memory T cells specific for a previously encountered virus could cross-react with other antigens, including contact allergens, drugs and other heterologous viruses in the absence of cognate antigen, and cause epidermal damage. This hypothesis provides an explanation for an intimate relationship between exposure to a number of exogenous agents, such as viruses and drugs, and the development of LP. In addition to T cells migrating from the circulation, T cells indigenously residing in the epidermis, such as intraepidermal CD8+ T cells, would also be involved in tissue damage. This population is typically detected at high frequencies in the resting lesion of fixed drug eruption, which is a simplified disease model for LP. Fucosyltransferase VII, essential for generating E-selectin ligand, is shown to play an indispensable role in inducing the accumulation of relevant skin-homing T cells at sites of LP lesions; however, the alternative notion should be appreciated that T cell recruitment to the skin is also crucial for host defense and that T cells frequently found in LP lesions could display beneficial properties for the host.