A Single-Center Prospective Cohort Study on Postsplenectomy Sepsis and its Prevention

British Society for Haematology guidelines to improve the care of asplenic patients: Much work done, some remaining and a call for national registries

Asplenic patients are at high risk of serious infectious or thrombotic complications, especially when they are not adequately informed of the risk and not closely followed. Ladhani et al. on behalf of the British Society for Haematology propose updated guidelines for managing these patients. Healthcare professionals need to improve infection prevention in patients with hypofunctional or absent spleen through better identification and immunisation using established national registries. Commentary on: Ladhani et al. Prevention and treatment of infection in patients with absent or hypofunctional spleen: A British Society for Haematology guideline. Br J Haematol 2024;204:1672-1686.

Efficacy of a novel patient-focused intervention aimed at increasing adherence to guideline-based preventive measures in asplenic patients: the PrePSS trial

PURPOSE

To determine whether a novel intervention improves the adherence to guideline-based preventive measures in asplenic patients at risk of post-splenectomy sepsis (PSS).

METHODS

We used a prospective controlled, two-armed historical control group design to compare a novel, health action process approach (HAPA)-based telephonic intervention involving both patients and their general practitioners to usual care. Eligible patients were identified in cooperation with the insurance provider AOK Baden-Wuerttemberg, Germany. Patients with anatomic asplenia (n = 106) were prospectively enrolled and compared to a historical control group (n = 113). Comparisons were done using a propensity-score-based overlap-weighting model. Adherence to preventive measures was quantified by the study-specific 'Preventing PSS score' (PrePSS score) which includes pneumococcal and meningococcal vaccination status, the availability of a stand-by antibiotic and a medical alert card.

RESULTS

At six months after the intervention, we estimated an effect of 3.96 (95% CI 3.68-4.24) points on the PrePSS score scale (range 0-10) with mean PrePSS scores of 3.73 and 7.70 in control and intervention group, respectively. Substantial improvement was seen in all subcategories of the PrePSS score with the highest absolute gains in the availability of stand-by antibiotics. We graded the degree of participation by the general practitioner (no contact, short contact, full intervention) and noted that the observed effect was only marginally influenced by the degree of physician participation.

CONCLUSIONS

Patients who had received the intervention exhibited a significantly higher adherence to guideline-based preventive measures compared to the control group. These data suggest that widespread adoption of this pragmatic intervention may improve management of asplenic patients. Health insurance provider-initiated identification of at-risk patients combined with a patient-focused intervention may serve as a blueprint for a wide range of other preventive efforts leading to patient empowerment and ultimately to better adherence to standards of care.

Effects of a health psychology-based intervention for patients with asplenia on psychological determinants of preventive behaviour: A propensity score analysis

OBJECTIVE

Patients with asplenia have an increased lifelong risk of severe infections especially post splenectomy sepsis with hospital mortality rates of 30-50%. Adherence to existing guidelines for preventive measures is low. Objective of the study is the evaluation of a novel intervention to increase health psychological outcomes in patients with asplenia resulting in better adherence to preventive measures.

METHODS

The intervention was evaluated by conducting a prospective, two-armed historical control group design via propensity score analysis. Focus are health-psychological outcomes: self-efficacy, intention, risk perception, behaviour planning, self-management, health literacy, patient involvement and disease-knowledge.

RESULTS

Patients in the intervention group (N = 110) showed a higher increase in almost all outcomes compared to a historical control group (N = 115). The strongest increase was observed in "asplenia-specific self-management" (average treatment effect: ATE 1.14 [95% CI 0.91-1.36] p < .001) and "asplenia-specific health-literacy" (ATE 1.42 [95% CI 1.18-1.65] p < .001). Significant intervention effects were also found in behaviour planning, perceived involvement and disease-knowledge.

CONCLUSION

The patient-focused intervention is effective in improving health-psychological outcomes in patients with asplenia.

PRACTICE IMPLICATIONS

The implementation of the intervention can make an important contribution to care and lead to an improvement of health-psychological outcomes that may result in a higher adherence to prevention measures.

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.

The Impact of Standardized Infectious Diseases Consultation on Post-Splenectomy Care and Outcomes

Background

Patients who receive splenectomy are at risk for overwhelming postsplenectomy infection (OPSI). Guidelines recommend that adult asplenic patients receive a complement of vaccinations, education on the risks of OPSI, and on-demand antibiotics. However, prior literature suggests a majority of patients who have had a splenectomy receive incomplete asplenic patient care and thus remain at increased risk. This study assessed the impact of standardized involvement of infectious diseases (ID) providers on asplenic patient care outcomes in patients undergoing splenectomy.

Methods

A quasi-experimental study design compared a prospective cohort of patients undergoing splenectomy from August 2017 to June 2021 who received standardized ID involvement in care of the asplenic patient with a historic control cohort of patients undergoing splenectomy at the same institution from January 2010 through July 2017 who did not. There were 11 components of asplenic patient care defined as primary outcomes. Secondary outcomes included the occurrence of OPSI, death, and death from OPSI.

Results

50 patients were included in the prospective intervention cohort and 128 in the historic control cohort. There were significant improvements in 9 of the 11 primary outcomes in the intervention arm as compared to the historic controls. Survival analysis showed no statistically significant difference in the incidence of OPSI-free survival between the groups (p = 0.056), though there was a trend towards improvement in the prospective intervention arm.

Conclusions

Standardized involvement of an ID provider in the care of patients undergoing splenectomy improves asplenic patient care outcomes. Routine involvement of ID in this setting may be warranted.

Portal vein thrombosis following elective laparoscopic splenectomy: incidence and analysis of risk factors

BACKGROUND

Minimally invasive splenectomy is now well established for a wide range of pathologies. Portal vein thrombosis (PVT) is increasingly being recognised as a complication of splenectomy. The aim was to determine the incidence and risk factors for PVT after laparoscopic splenectomy.

METHODS

All cases of elective laparoscopic splenectomy performed from 1993 to 2020 were reviewed. Parameters recorded included demographics, diagnostic criterion and post-operative outcomes. Data were analysed using Minitab V18 with a p < 0.05 considered significant.

RESULTS

210 patients (103 female, 107 male) underwent laparoscopic splenectomy (14 to 85 years). A major proportion of cases were performed for ITP (n = 77, p = 0.012) followed by lymphoma (n = 28), indeterminate lesions (n = 21) and myelofibrosis (n = 19). Ten patients developed symptomatic portal vein thrombosis (4.8%). Patients presented most commonly with pain and fever and diagnosis was confirmed by computed tomography (CT) or ultrasonography (USS). There were 10 conversions (4.8%) to open and two postoperative deaths, one from PVT and one from pneumonia. The remaining nine patients were successfully treated with anticoagulation. Of 19 patients with myelofibrosis, six patients developed PVT (p = 0.0002). Patients who developed PVT had significantly greater specimen weights (1773 g vs 348 g, p < 0.001). Forty-three patients had a specimen weight of 1 kg or greater, and of these 9 developed portal vein thrombosis (21%), versus one with PVT of 155 with a specimen weight of less than 1 kg (p < 0.0001). Myelofibrosis (p = 0.0039), specimen weight (p < 0.001) and mean platelet count (p = 0.0049) were predictive of PVT.

CONCLUSION

A high index of suspicion for this complication should be maintained and prompt treatment with anticoagulation. High-risk patients should be considered for prophylactic anticoagulation and routine imaging of the portal vein.

Exploring the metabolic phenotypes associated with different host inflammation of acute respiratory distress syndrome (ARDS) from lung metabolomics in mice

RATIONALE

The aim of this study was to analyze the metabolomics of lung with different host inflammation of acute respiratory distress syndrome (ARDS) for the identification of biomarkers for predicting severity under different inflammatory conditions.

METHODS

Cecal ligation and puncture (CLP) and lipopolysaccharide (LPS)-intratracheal injection induced acute lung injury (ALI) were used. A mouse model was used to explore lung metabolomic biomarkers in ALI/ARDS. The splenectomy model was used as an auxiliary method to distinguish between hyper- and hypo-inflammatory subtypes. Plasma, lung tissue and bronchoalveolar lavage fluid (BALF) samples were collected from mice after CLP/LPS. The severity of lung injury was evaluated. Expression of tumor necrosis factor-α (TNF-α) in mice serum and lung was tested by enzyme-linked immunosorbent assay (ELISA) and polymer chain reaction (PCR). Polymorphonuclear cells in BALF were counted. The lung metabolites were detected by gas chromatography/mass spectrometry (GC/MS), and the metabolic pathways predicted using the KEGG database.

RESULTS

The LPS/CLP-Splen group had more severe lung injury than the corresponding ALI group; that in the CLP-Splen group was more serious than in the LPS-Splen group. TNF-α expression was significantly elevated in the serum and lung tissue after LPS or CLP, and higher in the LPS/CLP-Splen group than in the corresponding ALI group. The level of TNF-α in the CLP-Splen group was elevated significantly over that in the LPS-Splen group. Both these groups also showed significant neutrophil exudation within the lungs. During differential inflammation, more differential metabolites were detected in the lungs of the CLP group ALI mice than in the LPS group. A total of 41 compounds were detected in the lungs of the CLP and CLP-Splen groups. Contrastingly, eight compounds were detected in the lungs of the LPS and LPS-Splen groups. The LPS-Splen and CLP-Splen groups had significant neutrophil exudation in the lung. Random forest analysis of lung-targeted metabolomics data indicated 4-hydroxyphenylacetic acid, 1-aminocyclopentanecarboxylic acid (ACPC), cis-aconitic acid, and hydroxybenzoic acid as strong predictors of the hyper-inflammatory subgroup in the CLP group. Furthermore, with splenectomy, 13 differential metabolic pathways between the CLP and LPS groups were revealed.

CONCLUSIONS

Hyper-inflammatory subgroups of ARDS have a greater inflammatory response and a more active lung metabolism. Combined with the host inflammation background, biomarkers from metabolomics could help evaluate the response severity of ARDS.

Preventing infections in children and adults with asplenia

An estimated 1 million people in the United States have functional or anatomic asplenia or hyposplenia. Infectious complications due to encapsulated organisms such as Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae can lead to fulminant sepsis and death, particularly in young children, in the period shortly after splenectomy, and in immunocompromised patients. Patients with asplenia are also at risk for less common infections due to Capnocytophaga, Babesia, and malaria. Antibiotic prophylaxis, vaccines, and patient and family education are the mainstays of prevention in these at-risk patients. Recommendations for antibiotic prophylaxis typically target high-risk periods, such as 1 to 3 years after splenectomy, children ≤5 years of age, or patients with concomitant immunocompromise. However, the risk for sepsis is lifelong, with infections occurring as late as 40 years after splenectomy. Currently available vaccines recommended for patients with asplenia include pneumococcal vaccines (13-valent pneumococcal conjugate vaccine followed by the 23-valent pneumococcal polysaccharide vaccine), meningococcal vaccines (meningococcal conjugate vaccines for serogroups A, C, Y and W-135 and serogroup B meningococcal vaccines), H. influenzae type b vaccines, and inactivated influenza vaccines. Ongoing booster doses are also recommended for pneumococcal and meningococcal vaccines to maintain protection. Despite the availability of prevention tools, adherence is often a challenge. Dedicated teams or clinics focused on patient education and monitoring have demonstrated substantial improvements in vaccine coverage rates for individuals with asplenia and reduced risk of infection. Future efforts to monitor the quality of care in patients with asplenia may be important to bridge the know-do gap in this high-risk population.

miR-331 inhibits CLDN2 expression and may alleviate the vascular endothelial injury induced by sepsis

The present study aimed to determine the expression level of claudin-2 (CLDN2) in the peripheral blood of patients with sepsis, and to investigate its potential function and mechanism of action in vascular endothelial injury. A total of 25 patients with sepsis were included in the present study. Reverse transcription-quantitative PCR was used to determine CLDN2 levels in peripheral blood. HUVECs stably expressing CLDN2 were prepared and Cell Counting Kit-8, flow cytometry and Transwell assays were performed to study the proliferation, apoptosis and migration of HUVECs, respectively. Using bioinformatics, microRNA (miR) molecules that interact with CLDN2 were predicted. A dual luciferase reporter assay was used to test whether miR-331 regulated CLDN2. Western blotting was employed to determine CLDN2 protein expression. In addition, in vitro transfection of HUVECs with miR-331 mimics was performed to test the rescue effects of miR-331 on the cell function changes induced by CLDN2. The results indicated that elevated CLDN2 expression altered the proliferation and cell cycle of peripheral vascular endothelial cells. CLDN2 overexpression inhibited HUVEC proliferation via mechanisms not associated with the cell cycle. CLDN2 mRNA levels in the peripheral blood of patients with sepsis were significantly higher than those in healthy subjects. Upregulated CLDN2 expression promoted the apoptosis of HUVECs, but reduced their proliferation and migration. Notably, miR-331 was able to bind with CLDN2 mRNA and regulate its expression. Upregulation of miR-331 expression inhibited the expression of CLDN2 and restored nearly normal proliferation, apoptosis and migration to HUVECs. The present study demonstrated that CLDN2 expression is elevated in peripheral blood from patients with sepsis, and promotes the injury of vascular endothelial cells. In addition, miR-331 participates in the direct regulation of CLDN2, and upregulation of miR-331 expression inhibits the expression of CLDN2 and restores cellular functions to HUVECs.