Liver regeneration after splenectomy in patients with liver cirrhosis

Splenectomy ameliorates liver cirrhosis by restoring the gut microbiota balance

BACKGROUND

Dysbiosis of gut microbiota is frequent in liver cirrhosis (LC) patients, and splenectomy (SP) has been reported to improve LC. Herein, we report the effects of SP on gut microbiota, especially on Veillonella parvula, a Gram-negative coccus of the gastrointestinal tract, in LC mice, and the underlying mechanism.

METHODS

LC mice models were induced by tail vein injection of concanavalin A (ConA), followed by SP. 16 s rRNA sequencing was conducted to analyze the effects of ConA induction and SP on mouse gut microbiota and the gene expression affected by gut microbiota. LC mice receiving SP were gavaged with Veillonella parvula. Likewise, hepatic stellate cells (HSC) and hepatocytes (HC) were induced with conditioned medium (CM) of Veillonella parvula.

RESULTS

SP alleviated LC in mice by restoring gut barrier function and maintaining gut microbiota balance, with Veillonella as the key genus. The Veillonella parvula gavage on LC mice reversed the ameliorative effect of SP. The CM of Veillonella parvula promoted the activation of HSC and the release of IL-6, IL-1β, and TNF-α. Also, the CM of Veillonella parvula induced HC pyroptosis and the release of ALT and AST. Veillonella parvula represented an imbalance in the gut microbiota, thus enhancing gut-derived endotoxins in the liver with the main target being Tlr4/Nlrp3. Inhibition of Tlr4 blocked Veillonella parvula-induced HC damage, HSC activation, and subsequent LC progression.

CONCLUSION

SP-mediated gut microbiota regulation ameliorates ConA-related LC progression by inhibiting Tlr4/Nlrp3 in the liver.

The spleen as a possible source of serine protease inhibitors and migrating monocytes required for liver regeneration after 70% resection in mice

Introduction: The role of the immune system in liver repair is fundamentally complex and most likely involves the spleen. The close connection between the two organs via the portal vein enables delivery of splenic cytokines and living cells to the liver. This study evaluates expression of inflammation-related genes and assesses the dynamics of monocyte-macrophage and lymphocyte populations of the spleen during the recovery from 70% hepatectomy in mice. Methods: The study used the established mouse model of 70% liver volume resection. The animals were sacrificed 24 h, 72 h or 7 days post-intervention and splenic tissues were collected for analysis: Clariom™ S transcriptomic assay, immunohistochemistry for proliferation marker Ki-67 and macrophage markers, and flow cytometry for lymphocyte and macrophage markers. Results: The loss and regeneration of 70% liver volume affected the cytological architecture and gene expression profiles of the spleen. The tests revealed significant reduction in cell counts for Ki-67+ cells and CD115+ macrophages on day 1, Ly6C + cells on days 1, 3 and 7, and CD3+CD8+ cytotoxic lymphocytes on day 7. The transcriptomic analysis revealed significant activation of protease inhibitor genes Serpina3n, Stfa2 and Stfa2l1 and decreased expression of cell cycle regulatory genes on day 1, mirrored by inverse dynamics observed on day 7. Discussion and conclusion: Splenic homeostasis is significantly affected by massive loss in liver volume. High levels of protease inhibitors indicated by increased expression of corresponding genes on day 1 may play an anti-inflammatory role upon reaching the regenerating liver via the portal vein. Leukocyte populations of the spleen react by a slow-down in proliferation. A transient decrease in the local CD115+ and Ly6C+ cell counts may indicate migration of splenic monocytes-macrophages to the liver.

Baseline ALBI Grade Predicts Benefits After Splenectomy for Cirrhotic Patients with Hypersplenism

PURPOSE

Splenectomy is an effective treatment for correcting cytopenia caused by hypersplenism secondary to cirrhosis. However, other potential benefits have not been well characterized. In this study, we investigated the value of splenectomy as it relates to improvement in hepatic function, liver regeneration, and health-related quality of life, and their association with baseline characteristics to clarify which patients may benefit the most from splenectomy.

METHODS

Patients with hypersplenism secondary to cirrhosis treated by splenectomy were retrospectively reviewed. Hepatic function was reflected by hematologic indices and albumin-bilirubin score. Liver volume was measured by imaging software, and quality-of-life was assessed by a 36-question short-form questionnaire. The changes in these three aspects after splenectomy were evaluated in the whole cohort and compared between subgroups.

RESULTS

The hepatic function of the patients significantly improved after splenectomy, and this was reflected by elevated serum albumin, shortened prothrombin time, and decreased albumin-bilirubin score. Patients with baseline albumin-bilirubin grade 2 or 3 and age < 56 years showed significantly decreased albumin-bilirubin score after splenectomy, whereas other subgroups did not. Moreover, liver volume increased remarkably after splenectomy in patients with baseline albumin-bilirubin grade 1, but not in those with grade 2 or 3. Significant improvement in quality-of-life occurred in the entire cohort after splenectomy, but more profound improvement was found in patients with albumin-bilirubin grade 2 or 3.

CONCLUSIONS

Splenectomy improves hepatic function, increases liver volume, and also improves quality-of-life in different subsets of patients with cirrhosis and hypersplenism. Baseline characteristics, such as albumin-bilirubin grade and age, are helpful in estimating the potential benefits of splenectomy for patients before surgery.

Individualized total laparoscopic surgery based on 3D remodeling for portal hypertension: A single surgical team experience

Background and aims

Portal hypertension (PHT) is common in end-stage cirrhosis, and variceal bleeding is the main complication associated with mortality. Surgery is usually performed in patients with PHT with a high risk of variceal bleeding in China. This study aimed to introduce an individualized and precise total laparoscopic surgical procedure based on 3D remodeling for PHT.

Methods

From March 2013 to December 2018, 146 patients with cirrhotic PHT underwent a laparoscopic surgical procedure in our department. An individualized 3D remodeling evaluation was carried out for surgical planning.

Results

The operation time was 319.96 ± 91.53 min. Eight of 146 patients were converted to open surgery. Acute portal vein system thrombosis occurred in 10 patients (6.85%). During the first year, 11 patients (8.15%) experienced rebleeding and two (1.48%) died. 18 patients (13.33%) experienced rebleeding and three died, giving a 3-year mortality rate of 3.66%. Compared with preoperatively, the portal vein showed significant postoperative decreases in diameter, flow velocity, and flow amount, while the hepatic artery showed significant postoperative increases in diameter, flow velocity, and flow amount. A 3D liver volume evaluation found that 19 of 21 patients had a significantly increased liver volume postoperatively, and a significantly decreased MELD score.

Conclusion

This retrospective study introduced a safe, feasible, and effective individualized surgical procedure. Our results show that this surgical treatment may not only act as an effective symptomatic treatment for PHT to prevent esophageal and gastric hemorrhage, but also as an etiological treatment to increase liver function and long-term survival.

Spleen: Reparative Regeneration and Influence on Liver

This review considers experimental findings on splenic repair, obtained in two types of small animal (mouse, rat, and rabbit) models: splenic resections and autologous transplantations of splenic tissue. Resection experiments indicate that the spleen is able to regenerate, though not necessarily to the initial volume. The recovery lasts one month and preserves the architecture, albeit with an increase in the relative volume of lymphoid follicles. The renovated tissues, however, exhibit skewed functional profiles; notably, the decreased production of antibodies and the low cytotoxic activity of T cells, consistent with the decline of T-dependent zones and prolonged reduction in T cell numbers. Species-specific differences are evident as well, with the post-repair organ mass deficiency most pronounced in rabbit models. Autotransplantations of splenic material are of particular clinical interest, as the procedure can possibly mitigate the development of post-splenectomy syndrome. Under these conditions, regeneration lasts 1-2 months, depending on the species. The transplants effectively destroy senescent erythrocytes, assist in microbial clearance, and produce antibodies, thus averting sepsis and bacterial pneumonia. Meanwhile, cellular sources of splenic recovery in such models remain obscure, as well as the time required for T and B cell number reconstitution.

Dual Effects of Large Spleen Volume After Splenectomy for the Patients With Chronic Liver Disease

Background

After splenectomy in patients with chronic liver disease, a large spleen was reported to be not only a risk factor of portal/splenic vein thrombosis (PSVT), but also a prediction for favorable improvement of liver function. This study aimed to evaluate the risk of PSVT and the improvement of liver function after splenectomy, with special attention to spleen volume (SV).

Methods

This studied included 50 patients who underwent splenectomy with diagnosed chronic liver disease between January 2005 and December 2017. After evaluation of risk factors for PSVT the cut-off value of SV for predicting PSVT was determined. According to the cut-off value of SV, 50 patients were divided into 2 groups: small-volume group (SVG) and large-volume group (LVG). Postoperative liver functions were compared between the 2 groups.

Results

Twenty-eight patients developed PSVT. Larger SV was the most significant independent risk factor for PSVT. The cut-off value of SV was 520 mL. Preoperatively, LVG had significantly higher total bilirubin, and MELD (model for end-stage liver disease) score, and had significantly higher rates of pancytopenia than SVG. Postoperatively, compared to SVG, platelet count, choline esterase, and total cholesterol in LVG were significantly increased.

Conclusion

After splenectomy in the patients with chronic liver disease, large SV is an independent risk factor for PSVT, with a clear benefit in improving liver function, if PSVT is properly diagnosed and managed.

Organ-organ communication: The liver's perspective

Communication between organs participates in most physiological and pathological events. Owing to the importance of precise coordination among the liver and virtually all organs in the body for the maintenance of homeostasis, many hepatic disorders originate from impaired organ-organ communication, resulting in concomitant pathological phenotypes of distant organs. Hepatokines are proteins that are predominantly secreted from the liver, and many hepatokines and several signaling proteins have been linked to diseases of other organs, such as the heart, muscle, bone, and eyes. Although liver-centered interorgan communication has been proposed in both basic and clinical studies, to date, the regulatory mechanisms of hepatokine production, secretion, and reciprocation with signaling factors from other organs are obscure. Whether other hormones and cytokines are involved in such communication also warrants investigation. Herein, we summarize the current knowledge of organ-organ communication phenotypes in a variety of diseases and the possible involvement of hepatokines and/or other important signaling factors. This provides novel insight into the underlying roles and mechanisms of liver-originated signal transduction and, more importantly, the understanding of disease in an integrative view.

Pretransplantation splenomegaly frequently persists after liver transplantation and can manifest as hypersplenism and graft fibrosis - a retrospective study

The risk factors and clinical impact of post-transplantation splenomegaly (SM) are poorly understood. We investigated the predictors and impacts of post-transplantation SM in 415 LT patients at Kyoto University Hospital from April 2006 to December 2015. First, the predictors and clinical consequences of SM three years post-transplantation were analyzed among spleen-preserved recipients. Second, the clinical data of surviving recipients three years post-transplantation were compared between splenectomized and spleen-preserved recipients. There was no difference in indication for liver transplantation between these two groups. Third, survival outcomes were compared between splenectomized and spleen-preserved recipients. SM was determined as a SV/body surface area (BSA) higher than 152 ml/m² . In the first analysis, preoperative SM occurred in 79.9% recipients and SM persisted three years post-transplantation in 72.6% recipients among them. Preoperative SV/BSA was the only independent predictor of three year post-transplantation SM, which was associated with lower platelet (PLT), white blood cell (WBC) counts and significant graft fibrosis (21.4% vs. 2.8%). In the second analysis, spleen-preservation was related to lower PLT, WBC counts and a higher proportion of significant graft fibrosis (26.7% vs. 7.1%) three years post-transplantation. In the third analysis, spleen-preserved recipients showed worse survival than splenectomized recipients. In conclusion, preoperative SM frequently persists more than three years post-transplantation and is associated with subclinical hypersplenism, graft fibrosis, graft loss, and even death.

Effect of laparoscopic splenectomy on portal vein thrombosis and serum YKL-40 in patients with cirrhotic portal hypertension

INTRODUCTION AND OBJECTIVES

Laparoscopic splenectomy (LS) is a supportive intervention for cirrhotic patients. However, its efficacy for patients with cirrhotic portal hypertension (CPH) still needs clarification. Studies indicated YKL-40 might be effective targets for treatment of splenomegaly, however deeper insights are unclear. The aim of this study was to investigate the effect of LS on the formation of portal vein thrombosis (PVT) and serum levels of a fibrosis marker, YKL-40, in patients with CPH.

MATERIALS AND METHODS

A total of 80 patients who underwent LS and 30 healthy controls were investigated in this study. Serum levels of YKL-40 were measured by enzyme-linked immunosorbent assay (ELISA). Demographic characteristics including age and gender were recorded. Clinicopathological and laboratory examinations included the severity of esophageal varices and the presence of viral hepatitis. The liver function was assessed according to the Child-Pugh classification. The incidence of PVT before and after operation was also monitored.

RESULTS

Serum YKL-40 was significantly increased in CPH patients, and was associated with Child-Pugh score and HBV infection. Furthermore, elderly patients had an increased risk for postoperative PVT. Higher serum YKL-40 was observed in patients with thrombus at postoperative 7, 14 and 21 days than those without thrombus.

CONCLUSIONS

LS could reduce serum YKL-40 levels and PVT progression and was a useful treatment for patients <40 years of age with CPH.

Splenic serum from portal hypertensive patients enhances liver stem cell proliferation and self-renewal via the IGF-II/ERK signaling pathway

BACKGROUND

Hypersplenism is a serious complication of portal hypertension (PH) and can affect the prognosis of liver disease. Liver stem cells (LSCs) are involved in liver regeneration and hepatocarcinogenesis after liver cirrhosis.

AIM

To explore the effects and mechanism of the spleen on the proliferation and differentiation of LSCs in PH due to liver cirrhosis.

METHODS

Fetal liver stem cells (FLSCs) were treated with splenic serum from liver cirrhosis patients with hypersplenism and control serum from healthy volunteers, and the proliferation, self-renewal, and IGF-II/ERK signaling pathway of FLSCs were then evaluated.

RESULTS

We found that splenic serum from PH patients promoted FLSC proliferation, colony formation, and Ki-67 expression in vitro. Splenic serum from PH also enhanced FLSC spheroid formation in vitro. Mechanistically, we determined that insulin-like growth factor (IGF)-II concentration was elevated in splenic serum from PH patients and could promote FLSC proliferation and self-renewal. Furthermore, both IGF-II and splenic serum from PH patients enhanced ERK signaling activation through IGF-I receptor (IGF-I R) in FLSCs. Consistently, blocking IGF-I R or ERK signaling could attenuate the effects of splenic serum from PH patients on FLSCs.

CONCLUSIONS

The spleen in PH patients promotes FLSC proliferation and self-renewal through the IGF-II/ERK signaling pathway.

Spleen-Associated Effects on Immunity in Hepatitis B Virus-Related Cirrhosis with Portal Hypertension

Our study aimed to investigate the histologic and immunological changes of portal hypertension (PH) pre- and postsplenectomy in hepatitis B virus (HBV)-related cirrhosis. Peripheral blood samples were obtained from 30 patients with HBV-related cirrhosis and PH at pre- and postsplenectomy time points and from 15 healthy subjects. Spleen tissue specimens were collected from 15 of the patients with HBV-related cirrhosis and from 8 control patients who had undergone splenectomy due to trauma. Immunohistochemical staining was performed to evaluate the immune effector cells and the expression of negative immune regulators. Flow cytometry was used to investigate the immunophenotypes and percentages. The spleen of cirrhotic patients with PH showed extensive depletion of splenic CD4, CD8, and human leukocyte antigen DR cells along with overexpression of the inhibitory receptors programmed death-1 (PD-1) and T cell immunoglobulin domain and mucin domain-3 and their ligands (PD-L2 and galectin-9). Peripheral blood of patients with PH showed remarkable decrease in proportions of CD8 T cell and natural killer (NK) cells and increase in regulatory T (Treg) cells, as well as high expression of PD-1 in CD4/8 T cells. Compared with presplenectomy patients, cirrhotic patients with PH showed increased proportions of CD8 and NK cells, decreased proportion of Treg cells, and decreased expression of PD-1 in peripheral blood CD4/8 T cells after splenectomy. PH-spleen could lead to peripheral tolerance and immunosuppression in HBV cirrhotic patients, and splenectomy may cause beneficial immunological changes.

Splenectomy Promotes Macrophage Polarization in a Mouse Model of Concanavalin A- (ConA-) Induced Liver Fibrosis

Background

Splenectomy can improve liver function and survival in patients with autoimmune hepatitis (AIH) and liver cirrhosis. We investigated the underlying mechanism in a mouse model of concanavalin A- (ConA-) induced liver fibrosis.

Methods

We used ConA to induce immune liver fibrosis in BALB/c mice. Splenectomy was performed alone or with the administration of dexamethasone (DEX). Changes in blood and liver tissues were evaluated.

Results

Mice treated with ConA for 7 weeks developed advanced liver fibrosis, while splenectomy suppressed liver fibrosis. Although the populations of macrophages/monocytes and M1 macrophages decreased after splenectomy, the inflammatory factors associated with M2 macrophages increased after splenectomy. Furthermore, the population of circulating CD11b⁺Ly6C^high myeloid-derived suppressor cells (MDSCs) increased after splenectomy. After ConA treatment, elevated levels of activated and total NF-kBp65/p50 combined with DNA were observed in hepatic tissues. In contrast, the levels of NF-κB p65/p50 decreased after splenectomy.

Conclusions

Splenectomy may promote the polarization of CD11b⁺Ly6C^high MDSCs and the differentiation of M2 macrophages while restricting the level of NF-κB p65-p50 heterodimers. These factors may suppress the progression of liver fibrosis.

Therapeutic implication of platelets in liver regeneration -hopes and hues

Mounting evidence highlights platelet involvement in liver regeneration via interaction with liver cells, growth factors release, and signaling contributions. Existing research suggests a compelling biological rationale for utilizing platelet biology, with the goal of improving liver function and accelerating its regenerative potential. Despite its expanding application in several clinical areas, the contribution of the platelet and its therapeutic implementation in liver regeneration so far has not yet fulfilled the initial high expectations. Areas covered: This review scrutinizes the progress, current updates, and discusses how recent understanding - particularly in the clinical implications of platelet-based therapy - may enable strategies to introduce and harness the therapeutic potential of the platelet during liver regeneration. Expert commentary: Several clinical and translational studies have facilitated a platform for the development of platelet-based therapy to enhance liver regeneration. While some of these therapies are effective to augment liver regeneration, the others have had some detrimental outcomes. The existing evidence represents a challenge for future projects that are focused on directly incorporating platelet-based therapies to induce liver regeneration.

The spleen in liver cirrhosis: revisiting an old enemy with novel targets

The spleen is a secondary lymphoid organ which can influence the progression of multiple diseases, notably liver cirrhosis. In chronic liver diseases, splenomegaly and hypersplenism can manifest following the development of portal hypertension. These splenic abnormalities correlate with and have been postulated to facilitate the progression of liver fibrosis to cirrhosis, although precise mechanisms remain poorly understood. In this review, we summarize the literature to highlight the mechanistic contributions of splenomegaly and hypersplenism to the development of liver cirrhosis, focusing on three key aspects: hepatic fibrogenesis, hepatic immune microenvironment dysregulation and liver regeneration. We conclude with a discussion of the possible therapeutic strategies for modulating splenic abnormalities, including the novel potential usage of nanomedicine in non-surgically targetting splenic disorders for the treatment of liver cirrhosis.