From sadness to stiffness: the spleen's progress

Specific Spleen-Accumulated NIR-II Fluorescent Probe for Imaging-Guided Splenic Operation

Spleen is a large immune organ in the body. Splenic operations such as splenectomy and intrasplenic injection are of paramount importance for immunological research and splenic diseases. Fluorescence imaging can vastly simplify these operations, but a specific spleen-targeting probe is still unavailable. Herein, the first specific spleen-accumulated fluorescent probe, VIX-S is reported, which fluoresces at 1064 nm and is highly stable. Systematic studies reveal the superior targeting and imaging performance of VIX-S for the spleen in both nude and haired mice. In vivo imaging indicates that the probe can image the morphology of spleen with a signal-background ratio of at least two-fold higher than that of the liver. Moreover, the application of VIX-S in imaging-guided splenic operation, including splenic injury and intrasplenic injection, is demonstrated, which may provide a practice tool for spleen research in the animal model.

Synthesis and SAR study of novel diimide skeleton compounds with the anti-inflammatory activities in vitro and in vivo

Amide bonds widely exist in the structure of natural products and drugs, and play an important role in biological activities. However, due to the limitation of synthesis conditions, there are few studies on biscarbonyl diimides. In this paper, a series of new compounds with diimide skeleton were synthesized by using CDI and NaH as condensation agents. The anti-inflammatory activity and cytotoxicity of the compound in RAW264.7 macrophages were evaluated by ELISA and MTT experiments. The results showed that these compounds had good anti-inflammatory activity in vitro, and the IC₅₀ of compound 4d on inflammatory factors IL-6 and TNF-α reached 1.59 μM and 15.30 μM, respectively. Further structure-activity relationship showed that biscarbonyl diimide and unsaturated double bond played a major role in the anti-inflammatory activity. In addition, compound 4d can alleviate acute lung injury (ALI) induced by LPS in vivo, reduce alveolar cell infiltration, and decrease the expression of ALI inflammatory factors. At the same time, compound 4d can significantly improve the survival rate of LPS-induced sepsis in mice. In short, the design and synthesis of the diimide skeleton provides a potential lead compound for the treatment of inflammatory diseases, and also provides a new idea for the design of amide compounds.

Retrospective assessment of the clinical efficacy of laparoscopic partial splenectomy

The present study aimed to explore the clinical efficacy of laparoscopic partial splenectomy in the treatment of benign lesions of the spleen and partial splenic rupture. The clinical value of laparoscopic partial splenectomies performed between March 2015 and May 2022 was retrospectively analyzed. Cases considered included the following: 14 spleen cysts, five spleen hemangiomas, one spleen hamartoma and two splenic ruptures. Lesion diameters of cases ranged from 5.0-11.3 cm. Results indicated that all 22 patients had an uneventful surgery, including 11 cases with lesions located in the upper pole of the spleen, nine in the lower pole of the spleen, one in the upper middle pole and one in the middle and lower pole. Operation time ranged from 75-180 min (mean: 120±17 min) and intraoperative bleeding ranged from 80-300 ml (mean: 178±70 ml). The average duration of postoperative hospitalization was 6±2 days, with all patients followed up for 10-12 months. Patients reported no symptoms of discomfort and had platelet levels within normal range. In conclusion, laparoscopic partial splenectomy allows for lesion resection while retaining normal splenic function and may be effectively used for treating benign spleen tumors and partial splenic rupture. However, the operation is difficult and surgeons must be able to perform minimally invasive techniques and strictly screen cases.

Asplenia and spleen hypofunction

Asplenia (the congenital or acquired absence of the spleen) and hyposplenism (defective spleen function) are common causes of morbidity and mortality. The spleen is a secondary lymphoid organ that is responsible for the regulation of immune responses and blood filtration. Hence, asplenia or hyposplenism increases susceptibility to severe and invasive infections, especially those sustained by encapsulated bacteria (namely, Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae type b). Asplenia is predominantly due to splenectomy for either traumatic events or oncohaematological conditions. Hyposplenism can be caused by several conditions, including haematological, infectious, autoimmune and gastrointestinal disorders. Anatomical disruption of the spleen and depletion of immune cells, especially IgM memory B cells, seem to be predominantly responsible for the clinical manifestations. Early recognition of hyposplenism and proper management of asplenia are warranted to prevent overwhelming post-splenectomy infections through vaccination and antibiotic prophylaxis. Although recommendations are available, the implementation of vaccination strategies, including more effective and immunogenic vaccines, is needed. Additionally, screening programmes for early detection of hyposplenism in high-risk patients and improvement of patient education are warranted.

Case report: Single-cell mapping of peripheral blood mononuclear cells from a patient with both Crohn’s disease and isolated congenital asplenia

Crohn’s disease (CD), as one of the principal form of inflammatory bowel disease (IBD), is characterized by the chronic and recurring inflammatory conditions in the intestine resulting from the over-activation of intestinal immunity. Hyposplenism is strongly associated with CD, while the effect of human spleen on the differentiation and development of immune cell subsets in CD patients remains unclear. Isolated congenital asplenia (ICA) is an extremely rare condition characterized by the absence of a spleen at birth without any other developmental defects. Here, we describe the first case of a patient with both ICA and CD, and follow the progression of CD from remission to active stage. Using cytometry by time of flight (CyTOF) analysis, we draw the first single-cell mapping of peripheral blood mononuclear cells (PBMC) from this unique patient, tracing back to the innate or adaptive immune cell subsets and cell surface markers affected by the spleen. Based on our analysis, it is speculated that the spleen contributes to maintaining immune homeostasis, alleviating intestinal inflammation and improving prognosis by influencing the differentiation and development of peripheral immune cell subsets and the expression of cell surface markers in patients with CD.

Ultrasound Assessment of the Relevance of Liver, Spleen, and Kidney Dimensions with Body Parameters in Adolescents

Objective

Ultrasound is a practical imaging modality for screening and identification of anomalies in the organs. This study used ultrasonography to examine the association between body parameters and dimensions of the normal liver, spleen, and kidney in adolescents based on ultrasound examination results.

Methods

A total of 300 junior and senior high school teenagers receiving routine health check-ups in our hospital from January 2020 to January 2021 were included. Their height and weight were measured, and their body surface area (BSA) and body mass index (BMI) were calculated. Ultrasound imaging was employed to obtain information such as the length and volume of the liver, gallbladder, spleen, and kidney. Besides, the correlation of body parameters such as gender, age, height, weight, BSA, and BMI with visceral dimension was investigated using the Pearson test and multiple regression analysis, respectively.

Results

We observed that the abdominal organs of adolescents were enlarged with age. The span and volume of the liver and the length and volume of the right kidney were significantly larger in boys than in girls. The age, BSA, and BMI were positively correlated with the liver span and spleen length, as well as the left and right kidney lengths. Additionally, age, BSA, and BMI were identified as important predictors for dimensions of the spleen, liver, and kidney.

Conclusions

Body parameters are notably associated with the dimensions of the liver, spleen, and kidney and could be utilized as predicting factors for the liver, spleen, and kidney dimensions.

Role of IgM Memory B Cells and Spleen Function in COVID-19

IgM memory B cells, are a peculiar subset of memory B cells, which probably originates in the spleen and outside germinal centers and provide a rapid line of defence against mucosal infections. Their role in counteracting COVID-19 is still elusive but, recent evidence, mainly boosted by studies on spleen function/involvement in COVID-19, seems to support the notion that this subset of memory B cells could exert a protective role against this virus, along with other coronaviruses, particularly in the acute setting of the infection, as outlined by worst clinical outcomes observed in unvaccinated patients with impaired IgM B memory response and spleen function. Herein we critically summarise the current landscape of studies on IgM memory B cells, focusing on the clinical impact of their depletion, by comparing the COVID-19-related splenic dysfunction with other hypo- and asplenic conditions and by adding recent data on follow-up studies and postulate a mechanistic explanation for their reduced numbers. The early detection of an impaired IgM memory B cell response in patients with COVID-19 may contribute to their improved care through different strategies, such as through tailored vaccine strategies, prompt hospital admission and/or administration of anti-infective treatments, thus resulting in an better prognosis, although at present management algorithms are still unavailable. Moreover, further studies with longer follow-up are needed to assess the evolution of COVID-19-associated/exacerbated immune deficit.

Hemostatic efficacy of two topical adjunctive hemostats in a porcine spleen biopsy punch model of moderate bleeding

Topical hemostatic agents have become essential tools to aid in preventing excessive bleeding in surgical or emergency settings and to mitigate the associated risks of serious complications. In the present study, we compared the hemostatic efficacy of SURGIFLO^® Hemostatic Matrix Kit with Thrombin (Surgiflo-flowable gelatin matrix plus human thrombin) to HEMOBLAST™ Bellows Hemostatic Agent (Hemoblast-a combination product consisting of collagen, chondroitin sulfate, and human thrombin). Surgiflo and Hemoblast were randomly tested in experimentally induced bleeding lesions on the spleens of four pigs. Primary endpoints included hemostatic efficacy measured by absolute time to hemostasis (TTH) within 5 min. Secondary endpoints included the number of product applications and the percent of product needed from each device to achieve hemostasis. Surgiflo demonstrated significantly higher hemostatic efficacy and lower TTH (p < 0.01) than Hemoblast. Surgiflo-treated lesion sites achieved hemostasis in 77.4% of cases following a single product application vs. 3.3% of Hemoblast-treated sites. On average, Surgiflo-treated sites required 63% less product applications than Hemoblast-treated sites (1.26 ± 0.0.51 vs. 3.37 ± 1.16). Surgiflo provided more effective and faster hemostasis than Hemoblast. Since both products contain thrombin to activate endogenous fibrinogen and accelerate clot formation, the superior hemostatic efficacy of Surgiflo in the porcine spleen punch biopsy model seems to be due to Surgiflo's property as a malleable barrier able to adjust to defect topography and to provide an environment for platelets to adhere and aggregate. Surgiflo combines a flowable gelatin matrix and a delivery system well-suited for precise application to bleeding sites where other methods of hemostasis may be impractical or ineffective.

Depletion of circulating IgM memory B cells predicts unfavourable outcome in COVID-19

Impaired immune responses have been hypothesised to be a possible trigger of unfavourable outcomes in coronavirus disease 2019 (COVID-19). We aimed to characterise IgM memory B cells in patients with COVID-19 admitted to an internal medicine ward in Northern Italy. Overall, 66 COVID-19 patients (mean age 74 ± 16.6 years; 29 females) were enrolled. Three patients (4.5%; 1 female) had been splenectomised and were excluded from further analyses. Fifty-five patients (87.3%) had IgM memory B cell depletion, and 18 (28.6%) died during hospitalisation (cumulative incidence rate 9.26/100 person-week; 5.8-14.7 95% CI). All patients who died had IgM memory B cell depletion. A superimposed infection was found in 6 patients (9.5%), all of them having IgM memory B cell depletion (cumulative incidence rate 3.08/100 person-week; 1.3-6.8 95% CI). At bivariable analyses, older age, sex, number of comorbidities, and peripheral blood lymphocyte count < 1500/µl were not correlated with IgM memory B cell depletion. A discrete-to-marked reduction of the B-cell compartment was also noticed in autoptic spleen specimens of two COVID-19 patients. We conclude that IgM memory B cells are commonly depleted in COVID-19 patients and this correlates with increased mortality and superimposed infections.

The spectrum of splenic complications in patients with sickle cell disease in Africa: a systematic review

The majority of the global population of sickle cell disease (SCD) patients resides in Africa. Individuals with this condition are at great risk of serious infections and early mortality secondary to splenic dysfunction without preventative measures. This review investigated the spectrum of splenic complications encountered in SCD among populations in Africa. We systematically searched several databases for all articles published through March 3, 2020. We included 55 studies from 14 African countries. This review reveals the difference in frequency of splenic complications in SCD in Africa when compared with their counterparts in the United State and Europe. While several studies (n = 45) described splenomegaly with a prevalence of 12% to 73% among children, and 4% to 50% among adults with HbSS, the reported prevalence for acute splenic sequestration crisis (n = 6 studies) and hypersplenism (n = 4 studies) was <10% and <5% respectively. A total of 30 surgical splenectomy was reported across eight studies. Only two (3.7%) studies provided data on spleen function. A conflicting pattern was observed amongst studies that evaluated the relationship between splenomegaly and the presence of bacterial and malaria infections. This review reveals the paucity of studies describing the role of SCD-induced splenic dysfunction in morbidity and infection related mortality in Africa.

Autoimmune gastritis

Autoimmune gastritis (AIG) is an increasingly prevalent, organ-specific, immune-mediated disorder characterized by the destruction of gastric parietal cells, leading to the loss of intrinsic factor and reduced acid output. These alterations result in malabsorption of iron, vitamin B₁₂ (pernicious anaemia) and potentially other micronutrients. For several years, most studies have focused on pernicious anaemia only, generating confusion between the two entities. In AIG, the gastric proton pump, H⁺/K⁺ ATPase, is the major autoantigen recognized by autoreactive T cells. The T cell-dependent activation of B cells stimulates the production of anti-parietal cell antibodies, the serological hallmark of AIG. The role of Helicobacter pylori infection in activating or favouring the autoimmune process is still uncertain. Early histopathological alterations allowing a more precise and prompt recognition have recently been described. AIG is burdened by a substantial diagnostic delay as it can present with varied clinical signs including, among others, gastrointestinal symptoms and neuropsychiatric manifestations. In advanced stages, AIG might progress to neuroendocrine tumours and gastric adenocarcinoma. Management includes early detection through a proactive case-finding strategy, micronutrient supplementation and endoscopic surveillance. This Primer comprehensively describes the most important insights regarding the epidemiology, pathophysiology, diagnosis and management of AIG, focusing on the most controversial, outstanding issues and future directions.

Preventing Infections by Encapsulated Bacteria Through Vaccine Prophylaxis in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), which comprises ulcerative colitis and Crohn's disease, is an immune-mediated, chronic-relapsing, disabling disorder which is associated with increased mortality and poor patients' quality of life. Patients with IBD are at increased risk of infections for many reasons. In fact, IBD often requires a lifelong immunosuppressive and/or biologic therapy, both commonly associated with respiratory and opportunistic infections, but also gastrointestinal, urinary tract infections, and sepsis. Moreover, impaired spleen function has been found in a considerable proportion of IBD patients, further increasing the risk of developing infections sustained by encapsulated bacteria, such as S. pneumoniae, H. influenzae, and N. meningitidis. Finally, comorbidities and surgery represent additional risk factors for these patients. Despite the availability of vaccinations against the most common serotypes of encapsulated bacteria, uncertainties still exist regarding a proper vaccination strategy and the actual effectiveness of vaccinations in this particular setting. Aim of this narrative review is to focus on the broad topic of vaccinations against encapsulated bacteria in IBD patients, discussing the clinical impact of infections, predisposing factors, vaccinations strategies, and unmet research and clinical needs.

Stigmatisation and resilience in inflammatory bowel disease

Inflammatory bowel disease, which includes Crohn's disease and ulcerative colitis, is an immune-mediated, chronic relapsing disorder characterised by severe gastrointestinal symptoms that dramatically impair patients' quality of life, affecting psychological, physical, sexual, and social functions. As a consequence, patients suffering from this condition may perceive social stigmatisation, which is the identification of negative attributes that distinguish a person as different and worthy of separation from the group. Stigmatisation has been widely studied in different chronic conditions, especially in mental illnesses and HIV-infected patients. There is a growing interest also for patients with inflammatory bowel disease, in which the possibility of disease flare and surgery-related issues seem to be the most important factors determining stigmatisation. Conversely, resilience represents the quality that allows one to adopt a positive attitude and good adjustments despite adverse life events. Likewise, resilience has been studied in different populations, age groups, and chronic conditions, especially mental illnesses and cancer, but little is known about this issue in patients with inflammatory bowel disease, even if this could be an interesting area of research. Resilience can be strengthened through dedicated interventions that could potentially improve the ability to cope with the disease. In this paper, we focus on the current knowledge of stigmatisation and resilience in patients with inflammatory bowel disease.