Post-splenectomy sepsis: preventative strategies, challenges, and solutions

Challenges in Diagnosing Post-Splenectomy Cytomegalovirus Mononucleosis

Cytomegalovirus (CMV) infection is often asymptomatic. However, in certain individuals, it can cause non-specific signs and symptoms that maybe hard to recognise. The condition may therefore be overlooked or misdiagnosed, leading to prolonged illness and serious sequelae. In this case report, we present a rare instance of CMV infection in an HIV-negative patient who had a remote history of splenectomy and was experiencing prolonged fever and markedly elevated white blood cell (WBC) count.

LEARNING POINTS

The clinical presentation of CMV infection in a post-splenectomy patient can be intricate and deceptive, involving non-specific symptoms such as prolonged fever and a markedly elevated WBC count.The decision on treatment among individuals without apparent risk factors (such as AIDS, transplant, or cancers) led to in-depth deliberations and discussion.Post-splenectomy patients with CMV infection may exhibit prolonged illness, potentially leading to severe consequences if left untreated.

Recent trends in organ-preserving pancreatectomy: Its problems and clinical advantages compared with other standard pancreatectomies

In this review article, we focus on recent papers on organ-preserving pancreatectomy procedures published since 2010. When comparing central pancreatectomy (CP) and distal pancreatectomy (DP), most studies have concluded that the CP group exhibited significantly lower incidence of new-onset diabetes or diabetes exacerbation than the DP group postoperatively. However, because of increased incidence of morbidities such as pancreatic fistula, the surgeon faces a considerable trade-off between increased short-term morbidity and long-term preservation of endocrine function. When the outcomes of two types of spleen-preserving DP (Kimura and Warshaw procedures) are compared, most studies mentioned the low incidence of postoperative gastric varices and splenic infarction with the Kimura procedure. Although there are several reports regarding the effect of spleen preservation on prevention of postoperative infections, no report on the contribution of spleen preservation to the prevention of overwhelming post-splenectomy infection is seen. The advantages of duodenum-preserving pancreatic head resection (DPPHR) concerning endocrine and exocrine functions continue to be subjects of discussion, mainly due to the limited number of institutions that have adopted this approach; however, DPPHR should be presented as an option for patients due to its low incidence of postoperative cholangitis. Organ-preserving pancreatectomy requires meticulous surgical techniques, and postoperative complications may increase with this surgery compared with standard pancreatectomy, which may be influenced by the surgeon's skill and the surgical facility where the procedure is performed. Nonetheless, this technique has significant long-term advantages in terms of endocrine and exocrine functions and its wider adoption in the future is expected.

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.

Serological and molecular detection of Toxoplasma gondii in ß. thalassemia patients

Toxoplasma gondii is a worldwide opportunistic protozoan causing life-threatening infection in immunocompromised patients, while frequently asymptomatic in immunocompetent individuals. The current study aimed to detect T. gondii; serologically and molecularly in ß. thalassemia patients and evaluate the association of infection with some hematological parameters in these patients. Blood samples were collected from 100 ß. thalassemia patients. Serological diagnosis of T. gondii using ELISA for IgG and IgM antibodies was performed. Molecular diagnosis by Real-Time (RE) PCR was performed using specifically designed primers amplifying 389 bp fragments of Toxoplasma genome. 45 patients (45%) had anti-Toxoplasma IgG antibodies with no detectable IgM antibodies while both anti-Toxoplasma IgM and IgG antibodies were noticed in 10 patients (10%). IgM only antibodies were discovered in two cases (2%). The total seropositivity rate among patients was 57%. RE PCR analysis revealed Toxoplasma DNA in 20% out of 100 patients. PCR and serological examination showed slight agreement. A statistically significant relation was observed between the results of IgG and IgM ELISA and PCR for the detection of T. gondii infection among patients with ß. thalassemia. None of the studied risk factors (age, gender, contact with cats, consumption of undercooked meat) or hematological parameters (ESR, anemia degree, ferritin level, type of blood transfusion, spleen status) showed statistically significant association with Toxoplasma infection. It can be concluded that patients with thalassemia have a high risk of infection with T. gondii. RE PCR should be used as a diagnostic method in association with serology especially in immunocompromised patients to increase sensitivity.

Selection of surgical modality for massive splenomegaly in children

BACKGROUND

Laparoscopic splenectomy (LS), a treatment for both benign and malignant splenic diseases, can prove technically challenging in patients with massive splenomegaly. In particular, the optimal surgical modality for treating massive splenomegaly in children remains controversial.

METHODS

The clinicopathologic data of 289 pediatric patients undergoing splenectomy for massive splenomegaly were studied in a retrospective analysis. Accordingly, the patients were classified into the LS surgery group and open splenectomy (OS) surgery group. In the laparoscopy cohort, they were separated into two subgroups according to the method of surgery: the multi-incision laparoscopic splenectomy (MILS) and the single-incision laparoscopic splenectomy (SILS) surgery groups, respectively. Patient demographics, clinical data, surgery, complications, and postoperative recovery underwent analysis. Concurrently, we compared the risk of adverse laparoscopic splenectomy outcomes utilizing univariable and multivariable logistic regression.

RESULTS

The total operation time proved remarkably shorter in the OS group in contrast to the LS group (149.87 ± 61.44 versus 188.20 ± 52.51 min, P < 0.001). Relative to the OS group, the LS group exhibited lowered postoperative pain scores, bowel recovery time, and postoperative hospitalization time (P < 0.001). No remarkable difference existed in post-operation complications or mortality (P > 0.05). Nevertheless, the operation duration was remarkably longer in the SILS surgery group than in the MILS surgery group (200 ± 46.11 versus 171.39 ± 40.30 min, P = 0.02). Meanwhile, the operative duration of MILS and SILS displayed a remarkable positive association with splenic length. Moreover, the operative duration of SILS displayed a remarkable positive association with the age, weight, and height of the sick children. Splenic length proved an independent risk factor of adverse outcomes (P < 0.001, OR 1.378).

CONCLUSIONS

For pediatric patients with massive splenomegaly who can tolerate prolonged anesthesia and operative procedures, LS surgery proves the optimal treatment regimen. SILS remains a novel surgery therapy which may be deemed a substitutional surgery approach for treating massive splenomegaly.

The Value of IgM Memory B-Cells in the Assessment of Splenic Function in Childhood Cancer Survivors at Risk for Splenic Dysfunction: A DCCSS-LATER Study

Background

Childhood cancer survivors (CCS) who received radiotherapy involving the spleen or total body irradiation (TBI) might be at risk for splenic dysfunction. A comprehensive screening test for examining splenic dysfunction is lacking.

Objective

We investigated whether IgM memory B-cells could be used to assess splenic dysfunction in CCS who received a splenectomy, radiotherapy involving the spleen, or TBI.

Methods

All CCS were enrolled from the DCCSS-LATER cohort. We analyzed differences in IgM memory B-cells and Howell-Jolly bodies (HJB) in CCS who had a splenectomy (n = 9), received radiotherapy involving the spleen (n = 36), or TBI (n = 15). IgM memory B-cells < 9 cells/µL was defined as abnormal.

Results

We observed a higher median number of IgM memory B-cells in CCS who received radiotherapy involving the spleen (31 cells/µL, p=0.06) or TBI (55 cells/µL, p = 0.03) compared to CCS who received splenectomy (20 cells/µL). However, only two CCS had IgM memory B-cells below the lower limit of normal. No difference in IgM memory B-cells was observed between CCS with HJB present and absent (35 cells/µL vs. 44 cells/µL).

Conclusion

Although the number of IgM memory B-cells differed between splenectomized CCS and CCS who received radiotherapy involving the spleen or TBI, only two CCS showed abnormal values. Therefore, this assessment cannot be used to screen for splenic dysfunction.

Machine Learning-Based Early Prediction of Sepsis Using Electronic Health Records: A Systematic Review

BACKGROUND

Sepsis, a life-threatening infection-induced inflammatory condition, has significant global health impacts. Timely detection is crucial for improving patient outcomes as sepsis can rapidly progress to severe forms. The application of machine learning (ML) and deep learning (DL) to predict sepsis using electronic health records (EHRs) has gained considerable attention for timely intervention.

METHODS

PubMed, IEEE Xplore, Google Scholar, and Scopus were searched for relevant studies. All studies that used ML/DL to detect or early-predict the onset of sepsis in the adult population using EHRs were considered. Data were extracted and analyzed from all studies that met the criteria and were also evaluated for their quality.

RESULTS

This systematic review examined 1942 articles, selecting 42 studies while adhering to strict criteria. The chosen studies were predominantly retrospective (n = 38) and spanned diverse geographic settings, with a focus on the United States. Different datasets, sepsis definitions, and prevalence rates were employed, necessitating data augmentation. Heterogeneous parameter utilization, diverse model distribution, and varying quality assessments were observed. Longitudinal data enabled early sepsis prediction, and quality criteria fulfillment varied, with inconsistent funding-article quality correlation.

CONCLUSIONS

This systematic review underscores the significance of ML/DL methods for sepsis detection and early prediction through EHR data.

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.

Long-term Results of Splenectomy in Transfusion-dependent Thalassemia

Splenectomy is indicated in transfusion-dependent thalassemia (TDT) only in certain situations. This study aimed to present the effectiveness, complications, and long-term follow-up results of splenectomy in children with TDT. We performed a 30-year single-institution analysis of cases of splenectomy for TDT between 1987 and 2017 and their follow-up until 2021. A total of 39 children (female/male: 24/15) were included. The mean age at splenectomy was 11.2±3.2 years, and their mean follow-up duration after splenectomy was 21.5±6.4 years. Response was defined according to the patient's annual transfusion requirement in the first year postsplenectomy and on the last follow-up year. Complete response was not seen in any of the cases; partial response was observed in 32.3% and no response in 67.6%. Thrombocytosis was seen in 87% of the patients. The platelet counts of 7 (17.9%) patients were >1000 (10 9 /L), and aspirin prophylaxis was given to 22 (56.4%) patients. Complications were thrombosis in 2 (5.1%) patients, infections in 11 (28.2%) patients, and pulmonary hypertension in 4 (10.2%) patients. Our study showed that after splenectomy, the need for transfusion only partially decreased in a small number of TDT patients. We think splenectomy can be delayed with appropriate chelation therapy up to higher annual transfusion requirement values.

Comparison of infectious complications after spleen preservation versus splenectomy during laparoscopic distal pancreatectomy for benign or low-grade malignant pancreatic tumors: A multicenter, propensity score-matched analysis

BACKGROUND

Previous studies have reported contrasting results regarding the advantages of spleen preservation during laparoscopic distal pancreatectomy (LDP) for preventing infectious complications.

METHODS

A total of 3787 patients who underwent LDP for benign or low-grade malignant pancreatic disease in 92 centers across Korea and Japan were included in this retrospective study. Postoperative infectious complications and other complications were compared between LDP with splenectomy (LDPS) and LDP with spleen preservation (LSPDP) by propensity score matching (PSM) analysis.

RESULTS

After PSM, the LSPDP group had a lower rate of overall infectious complications (P = .079) and a significantly lower rate of intra-abdominal abscess (P = .014) compared with the LDPS group. Within the LSPDP group, the vessel preservation subgroup had a significantly higher rate of infectious complications (P = .002) compared with the vessel resection subgroup. Low-volume centers had a higher rate of intra-abdominal abscess than high-volume centers in the LSPDP group (P = .001) and the splenic vessel preservation subgroup (P = .003).

CONCLUSIONS

Spleen preservation in LDP for benign or borderline malignant pancreatic diseases was advantageous in lowering the risk of infectious complications, specifically intra-abdominal abscess. However, the risk of intra-abdominal abscess may differ according to the level of surgeon's experience.

Cost-effectiveness of second-line therapies in adults with chronic immune thrombocytopenia

Major options for second-line therapy in adults with chronic immune thrombocytopenia (ITP) include splenectomy, rituximab, and thrombopoietin receptor agonists (TRAs). The American Society of Hematology guidelines recommend rituximab over splenectomy, TRAs over rituximab, and splenectomy or TRAs while noting a lack of evidence on the cost-effectiveness of these therapies. Using prospective, observational, and meta-analytic data, we performed the first cost-effectiveness analysis of second-line therapies in chronic ITP, from the perspective of the U.S. health system. Over a 20-year time-horizon, our six-strategy Markov model shows that a strategy incorporating early splenectomy, an approach at odds with current guidelines and clinical practice, is the cost-effective strategy. All four strategies utilizing TRAs in the first or second position cost over $1 million per quality-adjusted life-year, as compared to strategies involving early use of splenectomy and rituximab. In a probabilistic sensitivity analysis, early use of splenectomy and rituximab in either order was favored in 100% of 10 000 iterations. The annual cost of TRAs would have to decrease over 80% to begin to become cost-effective in any early TRA strategy. Our data indicate that effectiveness of early TRA and late TRA strategies is similar with the cost significantly greater with early TRA strategies. Contrary to current practice trends and guidelines, early use of splenectomy and rituximab, rather than TRAs, constitutes cost-effective treatment in adults with chronic ITP.

Sickle Cell Trait, Clinical Manifestations and Outcomes: A Cross-Sectional Study in Colombia: Increasing Rate of Symptomatic Subjects Living in High Altitude

Background

Sickle cell trait (SCT) is an autosomal recessive blood disorder in which patients are heterozygous carriers for hemoglobin S (HbAS) and are usually asymptomatic. We performed a descriptive analysis of clinical manifestations and outcomes associated with SCT.

Methods

This was a descriptive, cross-sectional study that included patients with SCT from 2014 to 2020 at Hospital Militar Central, the reference center of the Military forces in Bogota, Colombia.

Results

Of 647 hemoglobin electrophoresis analyzed, we identified 51 patients with SCT, including 43 males (84.3%) and eight females (15.7%), with a median age of 22 years (IQR 15-36 years). Of these, 28 (54.8%) were Afro-Colombian, 23 (45.1%) were Colombian mestizos, and 31/51 (60.8%) of patients were active military members. Twenty-four patients (47.1%) were asymptomatic, and Twenty-seven patients (52.9%) were symptomatic (systemic complications); Most of the patients who presented symptoms were active military members of the Colombian military forces. Splenic complications were the most important (85.2%), p=0.0005, and there was a wide spectrum of splenic complications. In addition, we found significant elevations in leukocytes, bilirubin, LDH, and CRP. Eighteen patients (66.7%) received medical management, five (18.5%) required splenectomy, and only 5.9% of patients were sent for genetic counseling.

Conclusions

Military Personnel is a population with a high risk of developing symptoms, and splenic complications were the most relevant in symptomatic patients. Most patients received medical treatment, and 18.5% of patients required splenectomy. Our results reflect the absence of redirection of these patients to genetic counseling.

Severity scoring system to guide transfusion management in pediatric non-deletional HbH

BACKGROUND

Hemoglobin (Hb) H is generally recognized as mild thalassemia, despite its actual phenotypic diversity. A disease severity scoring system to guide initiation of regular transfusion among severely affected pediatric patients has not previously been reported.

METHODS

Patients with HbH were classified into transfusion-dependent thalassemia (TDT) and non-transfusion-dependent thalassemia (NTDT) as a surrogate for disease severity. Alpha-globin genotypes and relevant clinical parameters associated with TDT were identified. Univariate and multiple logistic regression analyses were performed to yield the most suitable severity scoring system.

RESULTS

From 246 patients with a median age of 14.3 (interquartile range 9.9-18.4) years initially enrolled into the study, the chance of having severe disease and developing TDT was remarkable only among patients with non-deletional HbH, for whom the scoring system was developed. Univariate and multiple logistic regression analyses resulted in three retained parameters associated with TDT, β-coefficients of which were used to develop the score. The final scoring system comprised age at diagnosis <2 years (score = 1), spleen size ≥3 cm (score = 1) and Hb at steady-state <7 (score = 4) or 7-8 g/dL (score = 3). A cutoff score ≥4 was associated with severe disease likely requiring regular transfusion (sensitivity 89.3%, specificity 81.4%), given regular transfusion resulted in maintained growth. The scoring system was validated in the second cohort of 77 non-deletional HbH, from which comparable sensitivity and specificity were obtained.

CONCLUSION

The newly developed scoring system was practical and helpful to highlight severely affected pediatric non-deletional HbH patients with potential needs of regular transfusion. This can be used as a guide for optimal treatment and disease monitoring in the future.

Prophylactic Splenectomy and Hyposplenism in Spaceflight

BACKGROUND: There is debate whether astronauts traveling to space should undergo a prophylactic splenectomy prior to long duration spaceflight. Risks to the spleen during flight include radiation and trauma. However, splenectomy also carries significant risks.METHODS: Systematic review of data published over the past 5 decades regarding risks associated with splenectomies and risks associated with irradiation to the spleen from long duration spaceflight were analyzed. A total of 41 articles were reviewed.RESULTS: Acute risks of splenectomy include intraoperative mortality rate (from hemorrhage) of 3-5%, mortality rate from postoperative complications of 6%, thromboembolic event rate of 10%, and portal vein thrombosis rate of 5-37%. Delayed risks of splenectomy include overwhelming postsplenectomy infection (OPSI) at 0.5% at 5 yr post splenectomy, mortality rate as high as 60% for pneumococcal infections, and development of malignancy with relative risk of 1.53. The risk of hematologic malignancy increases significantly when individuals reach 40 Gy of exposure, much higher than the 0.6 Gy of radiation experienced from a 12-mo round trip to Mars. Lower doses of radiation increase the risk of hyposplenism more so than hematologic malignancy.CONCLUSION:For protection against hematologic malignancy, the benefits of prophylactic splenectomy do not outweigh the risks. However, there is a possible risk of hyposplenism from long duration spaceflight. It would be beneficial to prophylactically provide vaccines against encapsulated organisms for long duration spaceflight to mitigate the risk of hyposplenism.Siu M, Levin D, Christiansen R, Kelly E, Alouidor R, Kamine TH. Prophylactic splenectomy and hyposplenism in spaceflight. Aerosp Med Hum Perform. 2022; 93(12):877-881.

Patients' with asplenia and doctors' experiences in implementing preventative measures following a novel educational intervention: a qualitative analysis

OBJECTIVE

To explore patients' with asplenia and general practitioners' (GPs) (1) perceptions of a novel, Health Action Process Approach (HAPA)-based, educational intervention which targets to increase adherence to post-splenectomy sepsis (PSS) prevention measures and (2) their experience in implementing prevention measures following this intervention.

DESIGN

A process evaluation conducted on average 3.5 (for patients) and 3.8 (for GPs) months after the intervention between January 2020 and April 2021 individually by means of semi-structured guideline-based telephone interviews. Data was analysed using qualitative content analysis.

PARTICIPANTS

Volunteer subsample of N=25 patients with asplenia and N=8 GPs who received the intervention. Inclusion criteria were met by prior participation in the intervention (German-speaking, of full age and insured by the cooperating health insurance). Patient selection was done by purposeful selection aiming at maximum variability in terms of adherence to preventative measures prior to intervention participation. Participating GPs are a non-purposeful selected convenience sample. For reasons of data protection, no personal data was collected.

RESULTS

The intervention was positively evaluated and its personal relevancy for patients and for the GPs' professional work became apparent. The intervention promoted risk awareness, intention to action, action planning and subsequently, improved adherence to preventative measures. Helpful factors for implementation among the patients were social support by relatives and GPs. Barriers to adherence identified in both groups can be divided into patient-attributed (eg, comorbidities), doctor-related (eg, lack of knowledge or support) as well as contextual factors (eg, vaccine supply constraints).

CONCLUSIONS

Our findings indicate a patient and GP perceived benefit of the intervention, but still identify prevailing barriers to implementation. In a further step, a quantitative evaluation of the intervention will be conducted and recommendations for integrating the intervention in usual care will be made.

TRIAL REGISTRATION NUMBER

DRKS00015238.

The protective effect of the spleen in sickle cell patients. A comparative study between patients with asplenia/hyposplenism and hypersplenism

Sickle cell disease (SCD) is caused by a point mutation in the beta-globin gene. SCD is characterized by chronic hemolytic anemia, vaso-occlusive events leading to tissue ischemia, and progressive organ failure. Chronic inflammatory state is part of the pathophysiology of SCD. Patients with SCD have extremely variable phenotypes, from mild disease to severe complications including early age death. The spleen is commonly injured in SCD. Early splenic dysfunction and progressive spleen atrophy are common. Splenomegaly and hypersplenism can also occur with the loss of the crucial splenic function. Acute, life-threatening spleen-related complications in SCD are well studied. The association of laboratory parameters with the spleen status including hyposplenism, asplenia, and splenomegaly/hypersplenism, and their implication in vaso-occlusive crisis and long-term complications in SCD remain to be determined. We evaluated the association between the spleen status with clinical and laboratory parameters in 31 SCD patients: Group a) Patients with asplenia/hyposplenism (N = 22) (including auto-splenectomy and splenectomized patients) vs. Group b) patients with splenomegaly and or hypersplenism (N = 9). Laboratory studies included: Complete Blood Count, reticulocyte count, iron metabolism parameters, C Reactive Protein (CRP), Hb variant distribution, and D-dimer. Metabolic and morphological red blood cell (RBC) studies included: density gradient (by Percoll), glucose consumption, lactate release, and K⁺ leakage, fetal RBC (F-Cells) and F-Reticulocytes, annexinV+, CD71⁺, oxidative stress measured by GSH presence in RBC and finally Howell Jolly Bodies count were all analyzed by Flow Cytometry. Scanning electron microscopy analysis of RBC was also performed. Patients with asplenia/hyposplenism showed significantly higher WBC, platelet, Hematocrit, hemoglobin S, CRP, D-dimer, Gamma Glutamyl Transferase (GGT), cholesterol, transferrin, annexin V+ RBCs, CD71⁺ RBCs, together with a markedly lower F Reticulocyte levels in comparison with splenomegaly/hypersplenism patients. In summary, important differences were also found between the groups in the studied RBCs parameters. Further studies are required to elucidate the effect of the spleen including hyper and hypo-splenia on laboratory parameters and in clinical manifestations, vascular pathology, and long-term complications of SCD. The benefits and risks of splenectomy compared to chronic transfusion need to be evaluated in clinical trials and the standard approach managing hypersplenism in SCD patients should be re-evaluated.

Bacterial Etiology of Fever Episodes of Splenectomized Patients in Three Medical Centers in the City of Mashhad in Northeastern Iran

Background: Many medical and surgical conditions may need to be treated with splenectomy. As this lymphoid tissue plays an important role in controlling various infections, and many life-threatening infections can occur in the absence of the spleen, any episode of fever should be taken seriously. Objectives: This study aims to assess the bacterial etiology of fever episodes in splenectomized patients in three medical centers in Mashhad, a city in northeastern Iran. Methods: Between 2006 and 2017, splenectomized patients in Imam Reza, Ghaem, and Dr. Sheikh hospitals were included in a cross-sectional study. Data collected included, age at splenectomy, hospitalization duration, indications for admission to the intensive care unit, vital signs at admission, bacterial species responsible for sepsis, times of hospitalization due to fever episodes, clinical signs and symptoms, antibiotic prophylaxis, and outcomes at six and one years. The data were analyzed using SPSS Statistics 20. Results: A total of 280 splenectomized patients were reviewed, and 23 of them had episodes of fever. The most common causes of splenectomy were spleen masses and idiopathic thrombocytopenic purpura (ITP), each accounting for 17.4% of cases. The mean age of the patients was 24.2 ± 1.6 years. 47.8% of the patients were male, and 52.2% were female. The median admission duration was seven days. A majority of admissions were due to intra-abdominal infections (26.7%), pneumonia (13.3%), and bacteremia (10.0%). There were 30 episodes of fever recorded, of which 2 (6.7%) resulted in death. Blood culture was positive in four cases (13.3%) for Streptococcus pneumoniae, Staphylococcus aureus, Citrobacter, and Brucella. A suitable antibiotic coverage was obtained in 13.3% of cases (i.e., ceftriaxone + vancomycin or fluoroquinolone + vancomycin), and a minimum suitable empiric coverage was obtained in 10.0% of cases, and no appropriate antibiotic coverage was obtained in 76.7% of cases. Conclusions: The present study highlights widespread inappropriate empiric therapy of fever episodes in splenectomized patients, as well as a lack of due attention to timely sample collection before antibiotic administration. Despite this, the isolated organisms were varied and included S. pneumoniae, S. aureus, coagulase negative staphylococci, P. aeruginosa, Brucella, and Citrobacter.

High-fat diet activates splenic NOD1 and enhances neutrophil recruitment and neutrophil extracellular traps release in the spleen of ApoE-deficient mice

In the course of atherogenesis, the spleen plays an important role in the regulation of extramedullary hematopoiesis, and in the control of circulating immune cells, which contributes to plaque progression. Here, we have investigated the role of splenic nucleotide-binding oligomerization domain 1 (NOD1) in the recruitment of circulating immune cells, as well as the involvement of this immune organ in extramedullary hematopoiesis in mice fed on a high-fat high-cholesterol diet (HFD). Under HFD conditions, the absence of NOD1 enhances the mobilization of immune cells, mainly neutrophils, from the bone marrow to the blood. To determine the effect of NOD1-dependent mobilization of immune cells under pro-atherogenic conditions, Apoe^−/− and Apoe^−/−Nod1^−/− mice fed on HFD for 4 weeks were used. Splenic NOD1 from Apoe^−/− mice was activated after feeding HFD as inferred by the phosphorylation of the NOD1 downstream targets RIPK2 and TAK1. Moreover, this activation was accompanied by the release of neutrophil extracellular traps (NETs), as determined by the increase in the expression of peptidyl arginine deiminase 4, and the identification of citrullinated histone H3 in this organ. This formation of NETs was significantly reduced in Apoe^−/−Nod1^−/− mice. Indeed, the presence of Ly6G⁺ cells and the lipidic content in the spleen of mice deficient in Apoe and Nod1 was reduced when compared to the Apoe^−/− counterparts, which suggests that the mobilization and activation of circulating immune cells are altered in the absence of NOD1. Furthermore, confirming previous studies, Apoe^−/−Nod1^−/− mice showed a reduced atherogenic disease, and diminished recruitment of neutrophils in the spleen, compared to Apoe^−/− mice. However, splenic artery ligation reduced the atherogenic burden in Apoe^−/− mice an effect that, unexpectedly was lost in Apoe^−/−Nod1^−/− mice. Together, these results suggest that neutrophil accumulation and activity in the spleen are driven in part by NOD1 activation in mice fed on HFD, contributing in this way to regulating atherogenic progression.

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.

Congenital asplenia study: clinical and laboratory characterisation of adults with congenital asplenia

Congenital asplenia is a rare disorder commonly associated with other visceral and cardiac congenital anomalies. Isolated congenital asplenia is even less common than syndromic forms. The risk of severe bacterial infections associated with asplenia is the most concerning clinical implication and carries a significant mortality risk. Prophylactic measures against the clinical syndrome known as overwhelming postsplenectomy infections (OPSI) include vaccination, prophylactic and emergency antibiotics and health education including fever management and travel advice. This case series describes fourteen adults with congenital asplenia and polysplenia syndrome, most of whom were diagnosed incidentally as adults, and outlines the nature of their diagnosis, clinical phenotype, family history and key pathology findings.

Autoimmune Hemolytic Anemia in Children: Laboratory Investigation, Disease Associations, and Treatment Strategies

Autoimmune hemolytic anemia is a relatively uncommon pediatric clinical condition. As such, the evaluation and management of these cases can be challenging for even the most seasoned pediatrician. In this review, the 3 major forms of autoimmune hemolytic anemia in children will be discussed: warm autoimmune hemolytic anemia, cold agglutinin disease, and paroxysmal cold hemoglobinuria. After a general description of the laboratory approach to these entities, the pathophysiology of these disease processes, including important disease associations, will be described, and treatment strategies will be discussed. This will provide the reader with a rational approach to identifying and managing pediatric patients with these uncommon autoimmune conditions.

Efficacy, immunogenicity, and evidence for best-timing of pneumococcal vaccination in splenectomized adults: a systematic review

INTRODUCTION

: Streptococcus pneumoniae is the most frequent cause of overwhelming post-splenectomy infections. Pneumococcal vaccination is generally recommended for splenectomized individuals. However, most of our knowledge comes from a few observational studies or small randomized clinical trials. We conducted this systematic review to assess the evidence of efficacy, antibody response, and the best timing for pneumococcal vaccination in splenectomized individuals.

AREAS COVERED

: The systematic review was conducted according to the PRISMA guidelines. We screened 489 articles, included 21 articles, and assessed the risk of bias using Cochrane RoB 2 and ROBINS-I. We summarized the findings narratively due to the heterogeneity of the studies.

EXPERT OPINION

Splenectomized individuals seem to have adequate antibody responses to pneumococcal vaccines. No differences in antibody responses were observed compared to healthy controls, except in one study. The studies were heterogeneous, and the majority had moderate to high degree of bias. There is a lack of clinical evidence for efficacy and best timing of pneumococcal vaccination in splenectomized individuals. Randomized clinical trials addressing these issues are needed.

Splenic rupture presenting with marked scrotal ecchymosis in a 2-day-old newborn

Splenic rupture is a rare and severe condition in neonates. The signs and symptoms are vague and non-specific and are often not recognised before the onset of hypovolaemic shock or death. A 2-day-old infant presented with scrotal ecchymosis, and ultrasonography detected haemorrhage in the scrotal, right inguinal and adrenal regions. Computed tomography demonstrated a peri-splenic haematoma. Haemoglobin (Hb) was 2.79 g/dL and, despite repeated transfusions, the Hb level could not be sustained. Exploratory laparotomy detected a large haematoma in the splenic region, and, because of the uncontrolled haemorrhage, splenectomy was required.

Reduced Clostridioides difficile infections in hospitalised older people through multiple quality improvement strategies

OBJECTIVES

To reduce infections with Clostridioides difficile (CDI) in geriatric patients by interventions easily implementable in standard clinical care.

METHODS

Prevalence and incidence of CDI between January 2015 and February 2020 were analysed (n = 25,311 patients). Pre-intervention status was assessed from April 2016 to March 2017 (n = 4,922). Between May 2017 and August 2019, a monocentric interventional crossover study (n = 4,655) was conducted including standard care and three interventions: (A) sporicidal cleaning of hospital wards, (B) probiotics and (C) improvement in personal hygiene for CDI patients. This was followed by a multicentric comparison of the interventional bundle (A + B + C) between September 2019 and February 2020 (n = 2,593) with the pre-intervention phase. In 98 CDI cases and matched controls individual risk factors for the development of CDI were compared.

RESULTS

Time series analyses of CDI cases revealed a reduction in the prevalence of CDI in all three participating centres prior to the multicentric intervention phase. In the monocentric phase, no effect of individual interventions on CDI prevalence was identified. However, an aggregated analysis of CDI cases comparing the pre-intervention and the multicentric phase revealed a significant reduction in CDI prevalence. Risk factors for the development of CDI included use of antibiotics, anticoagulants, previous stay in long-term care facilities, prior hospital admissions, cardiac and renal failure, malnutrition and anaemia.

CONCLUSIONS

The observed reduction in CDI may be attributed to heightened awareness of the study objectives and specific staff training. Individual interventions did not appear to reduce CDI prevalence. A further randomised trial would be necessary to confirm whether the bundle of interventions is truly effective.

Role of Partial Splenectomy in Hematologic Childhood Disorders

The spleen is a secondary lymphoid organ that belongs to the reticular-endothelial system, directly connected to blood circulation. The spleen is greatly involved in the immune response, especially against capsulated bacteria. Splenectomy plays a fundamental role in the treatment of numerous pediatric hematologic disorders. Taking into account all the possible complications (especially infections) linked to this procedure, alternatives to total splenectomy have been sought. Partial splenectomy has been proposed as a treatment that allows the reduction of infectious risk. This approach has proven safe and feasible in most patients, but multicentric and prospective studies are necessary to more accurately define the indications for performing partial splenectomy. However, vaccinations and antibiotic prophylaxis remain fundamental for preventing serious infections, even in the case of partial splenectomy. We review anatomical and functional properties of the spleen, with a focus on medical or surgical indications to splenectomy, aiming to give practical educational information to patients and their families after splenectomy. Furthermore, we discuss the feasibility of partial splenectomy in children with hematologic diseases who require splenectomy.

Pneumococcal Vaccination in Immunocompromised Hosts: An Update

Infections with the pathogen, Streptococcus pneumoniae, are a common cause of morbidity and mortality worldwide. It particularly affects those at the extremes of age and immunocompromised individuals. Preventing pneumococcal disease is paramount in at risk individuals, and pneumococcal vaccination should be offered. Here, we discuss the role of pneumococcal vaccination in specific groups of immunocompromised hosts.

Pneumococcal vaccine coverage in Japan among patients with a history of splenectomy: Results of a retrospective administrative database study

BACKGROUND

Splenectomy results in immune deficiency and increases the risk of clinically significant infections, termed overwhelming post-splenectomy infection (OPSI). In Japan, vaccination with the 23-valent pneumococcal polysaccharide vaccine (PPSV23) is covered by the Japanese National Health Insurance (NHI) for post-splenectomy patients, but there are limited data about whether these patients receive PPSV23 vaccination.

METHODS

We performed retrospective analyses of the JMDC Claims Database comprising employees (including some retired individuals) and their families in Japan. We identified patients who underwent splenectomy (registration period: January 1, 2005-June 30, 2019) at ≥ 2 to ≤ 64 years old, and obtained information about PPSV23 vaccination, reasons for splenectomy, and prevalence/complications of pneumococcal infectious diseases (including OPSI-related disorders).

RESULTS

Among 7,394,182 registered individuals, splenectomy was performed in 475, with an incidence rate of 1.6 cases per 100,000 person-years. Of 414 patients who underwent splenectomy at ≥ 2 to ≤ 64 years of age, their mean ± standard deviation age was 45.4 ± 15.7 years and 63.3% were 45-64 years old. Splenectomy was incidental in 55.3%. Overall, 123/414 patients were prescribed PPSV23 vaccination, resulting in vaccination coverage of 29.7%. The median interval from splenectomy to vaccination was 1.0 month (range: -1 to 85 months).

CONCLUSION

This was the first study to document PPSV23 vaccination coverage after splenectomy in a Japanese real-world setting. PPSV23 coverage is quite low in Japan relative to that in other countries.

Radiotherapy for symptom palliation of splenomegaly in patients with haematological malignancies

Splenomegaly severely compromises the quality of life of those affected. The aim of the present study was to describe the clinical characteristics of patients with haematological disorders who receive radiotherapy for splenomegaly, particularly focusing on the changes in spleen volume. The present study conducted a retrospective analysis of consecutive patients with haematological disorders who underwent splenic radiotherapy with palliative intent at the Department of Radiology of the University of Tokyo Hospital between June 2008 and June 2019. Pre- and post-radiotherapy spleen volumes were measured from computed tomography images. A total of 8 patients (5 men and 3 women) with a median age of 59 years (range, 46-76 years) were included. The median total prescription and fractional doses were 4.5 Gy (range, 1.5-10 Gy) and 0.78 Gy (range, 0.5-2.0 Gy), respectively. A total of 5 patients (62.5%) experienced a reduction in spleen volume. The mean ± SD spleen sizes pre- and post-radiotherapy were 1,887±1,011 and 1,368±577 ml, respectively. The mean variation rate in spleen volume was -19.1±24.7%, and the case with the most notable improvement in the present study exhibited a -52.4% change. Of the 5 patients who experienced pain prior to radiotherapy, 3 achieved pain relief, 1 did not experience any change and 1 patient was not assessed post-radiotherapy. Therefore, the findings of the present study revealed that palliative radiotherapy for splenomegaly may achieve symptom palliation and radiological volumetric effects in patients with haematological disorders.

A BERIBERI UNHEALTHY LATTE: ENCEPHALOPATHY AND SHOCK FROM SEVERE NUTRITIONAL DEFICIENCY

BACKGROUND

Thiamine deficiency is an uncommon cause of severe illness in the United States that can lead to significant morbidity because of high-output cardiac failure, peripheral neuropathy, and permanent neurologic impairment. We report the case of a middle-aged woman with extreme malnutrition caused by complications of Roux-en-Y gastric bypass (RYGB) surgery who presented with signs and symptoms of severe thiamine deficiency and septic shock.

CASE REPORT

A 43-year-old woman who had undergone RYGB surgery and who had multiple complications presented to the emergency department with agitation, confusion, and lethargy. The physical examination revealed an obtunded woman appearing much older than her reported age with significant peripheral edema. She was hypoxemic, hypotensive, and febrile. The initial laboratory analysis revealed a serum lactate level above the measurable limit, a normal thyroid-stimulating hormone, and elevated levels of troponin and brain natriuretic peptide. A transthoracic echocardiogram showed high-output heart failure. The patient's family later revealed that for the past year her diet had consisted almost exclusively of frozen blended lattes. High doses of thiamine and folate were started. Her shock, hyperlactatemia, and respiratory failure resolved by hospital day 3 and her encephalopathy resolved soon thereafter. Why Should an Emergency Physician be Aware of This?: Thiamine deficiency is a rare but reversible cause of shock, heart failure, and encephalopathy. Identifying patients who are at risk for severe nutritional deficiencies may aid in more rapid treatment with relatively benign medications with little downside, in this case high-dose vitamin B₁, and ultimately improve patient-oriented outcomes such as mortality, morbidity, and hospital length of stay.

Vaccination coverage among paediatric onco-haematological patients: an Italian cross-sectional study

Children with onco-hematological diseases are at increased risk of infection. However, this risk can in part be controlled or reduced using currently available vaccines. Despite available evidence, in patients diagnosed with a hematological or oncological disease the vaccination schedule is often inappropriately discontinued. In this study we evaluated whether the diagnosis of an oncological or hematological disease is a determinant of noncompliance with recommended vaccinations.The study was carried out between March and April 2019. The population was composed of a convenience sample of 228 children cared for in the Pediatric Oncology Department and Pediatric Hematology Department of the Policlinico Giovanni XXIII Pediatric Hospital (Bari, Italy) from 2005 to 2015. Information on the immunization status of the patients was obtained from the Apulia regional immunization database (GIAVA). A post-diagnosis adherence score was calculated.The vaccination coverage was 87.7% for the DTaP-IPV-Hep B-Hib vaccine (3 doses), 68.7% for the pneumococcal vaccine (3 doses), 75.8% for the MMR vaccine (2 doses) and 75.1% for the varicella vaccine (2 doses). The average age at vaccination was older than that recommended by the National Vaccination Plan. A diagnosis of oncological disease and an older age at enrollment were risk factors for missing vaccinations. These results showed that the overall vaccination status of pediatric onco-hematological patients is suboptimal. Improving provider communication and establishing the hospital as the primary environment for vaccine administration may lead to better vaccination compliance in this group.

Immunization coverage among asplenic patients and strategies to increase vaccination compliance: a systematic review and meta-analysis

BACKGROUND

Asplenic or splenectomized patients have a higher risk (ranging from 10 to 50-fold) than the general population of developing an overwhelming post-splenectomy infection (OPSI). Thus, they should receive specific vaccinations to prevent bacterial infections and influenza. The aim of this meta-analysis was to estimate vaccination coverage (VC) with the recommended vaccines among splenectomized patients; strategies recommended in those studies to improve VC worldwide are considered as well.

RESEARCH DESIGN AND METHODS

Scopus, MEDLINE/PubMed, Google Scholar and ISI Web of Knowledge databases were searched. Research papers, short reports, reviews, and meta-analyses published between January 1, 2010 and July 18, 2020 were included; no geographic restrictions were included. Twenty-four studies were included in the meta-analysis.

RESULTS

For anti-pneumococcal vaccination, coverage was 55.1% (95%CI = 41.0-69.2%), for anti-Hib 48.3% (95%CI = 34.3-52.3%), for anti-meningococcal C/ACYW135 33.7% (95%CI = 23.6-43.9%), for anti-meningococcal B 13.3% (95%CI = 7.0-19.5%) and for anti-influenza 53.2% (95%CI = 22.0-84.4%). Most studies determined a lack of adherence to international guidelines by healthcare workers and suggested the need to better educate health professionals in the management of post-splenectomy patients.

CONCLUSIONS

The meta-analysis showed the suboptimal immunization coverage for the vaccines recommended for asplenic patients. Greater efforts must be made by public health professionals to increase VC in this group of patients at risk. Introducing specific prophylaxis protocols in the clinical routine seems to guarantee better immunization compliance in those patients.

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.

The spleen as an organ at risk in paediatric radiotherapy: A SIOP-Europe Radiation Oncology Working Group report

BACKGROUND

Radiation may cause long-term splenic dysfunction, risking potentially fatal late sepsis. We aimed to review this complication's magnitude in paediatric radiotherapy and gauge the level of awareness of the spleen as an organ at risk.

METHODS

Clinical trial protocols and radiotherapy guidelines, patient/parent information sheets, and professional guidance documents were reviewed to assess the perceived risk of radiotherapy-related splenic dysfunction. Paediatric oncologists and paediatric radiation oncologists across Europe were surveyed to estimate the level of understanding of this risk and to ascertain current practice. Spleen doses received in practice were examined. A systematic review of relevant publications was undertaken.

RESULTS

The risk is not mentioned in most clinical trials, patient information leaflets, or professional guidance documents. When mentioned, a threshold dose of 40 Gy is cited. The survey showed only limited awareness. More than half of patients assessed received spleen doses in excess of 10 Gy. The systematic review identified one paper reporting a relative mortality risk of 5.5 with spleen doses in the 10-20 Gy range.

CONCLUSIONS

The risk of mortality from overwhelming infection is poorly recognised. We therefore recommend routine delineation of the spleen. Protocols and guidelines should give a spleen dose objective as low as reasonably achievable, ideally mean <10 Gy without compromise to target volumes. Revised evidence-based guidelines and continuing professional development activities should inform oncologists. Patient/parent information should mention the risk and the dose received be communicated to colleagues. Antibiotic prophylaxis and/or (re)vaccination should be considered if the mean spleen dose is ≥10 Gy.

How I approach hereditary hemolytic anemia and splenectomy

Hereditary hemolytic anemias (HHA) are a heterogeneous group of anemias associated with decreased red cell survival. While there can be clinical benefit of splenectomy in many cases, splenectomy is not appropriate for all types of HHA. Additionally, there are significant risks during and following splenectomy including surgical risks, postsplenectomy sepsis, and thrombotic complications. This review discusses the diagnostic approach to HHA as well as the role of splenectomy in the management. Surgical approaches and outcomes for total and partial splenectomy are discussed.

Clinical implications of increased uptake in bone marrow and spleen on FDG-PET in patients with bacteremia

PURPOSE

To investigate which clinical factors and laboratory values are associated with high FDG uptake in the bone marrow and spleen on 2-deoxy-2-[18F]fluoro-D-glucose (FDG) positron emission tomography (PET)/computed tomography (CT) in patients with bacteremia.

METHODS

One hundred forty-five consecutive retrospective patients with bacteremia who underwent FDG-PET/CT between 2010 and 2017 were included. Mean standard uptake values (SUV_mean) of FDG in bone marrow, liver, and spleen were measured. Bone marrow-to-liver SUV ratios (BLR) and spleen-to-liver SUV ratios (SLR) were calculated. Linear regression analyses were performed to examine the association of BLR and SLR with age, gender, hemoglobin, leukocyte count, platelets, glucose level, C-reactive protein (CRP), microorganism, days of antibiotic treatment before FDG-PET/CT, infection focus, use of immunosuppressive drugs, duration of hospital stay (after FDG-PET/CT), ICU admission, and mortality.

RESULTS

C-reactive protein (p = 0.006), a cardiovascular or musculoskeletal focus of infection (p = 0.000 for both), and bacteremia caused by Gram-negative bacteria (p = 0.002) were independently and positively associated with BLR, while age (p = 0.000) and glucose level before FDG-PET/CT (p = 0.004) were independently and negatively associated with BLR. For SLR, CRP (p = 0.001) and a cardiovascular focus of infection (p = 0.020) were independently and positively associated with SLR, while age (p = 0.002) and glucose level before FDG-PET/CT (p = 0.016) were independently and negatively associated with SLR.

CONCLUSION

High FDG uptake in the bone marrow is associated with a higher inflammatory response and younger age in patients with bacteremia. In patients with high FDG uptake in the bone marrow, a cardiovascular or musculoskeletal focus of infection is more likely than other foci, and the infection is more often caused by Gram-negative species. High splenic FDG uptake is associated with a higher inflammatory response as well, and a cardiovascular focus of infection is also more likely in case of high splenic FDG uptake.

Contribution of Extramedullary Hematopoiesis to Atherosclerosis. The Spleen as a Neglected Hub of Inflammatory Cells

Cardiovascular diseases (CVDs) incidence is becoming higher. This fact is promoted by metabolic disorders such as obesity, and aging. Atherosclerosis is the underlying cause of most of these pathologies. It is a chronic inflammatory disease that begins with the progressive accumulation of lipids and fibrotic materials in the blood-vessel wall, which leads to massive leukocyte recruitment. Rupture of the fibrous cap of the atherogenic cusps is responsible for tissue ischemic events, among them myocardial infarction. Extramedullary hematopoiesis (EMH), or blood cell production outside the bone marrow (BM), occurs when the normal production of these cells is impaired (chronic hematological and genetic disorders, leukemia, etc.) or is altered by metabolic disorders, such as hypercholesterolemia, or after myocardial infarction. Recent studies indicate that the main EMH tissues (spleen, liver, adipose and lymph nodes) complement the hematopoietic function of the BM, producing circulating inflammatory cells that infiltrate into the atheroma. Indeed, the spleen, which is a secondary lymphopoietic organ with high metabolic activity, contains a reservoir of myeloid progenitors and monocytes, constituting an important source of inflammatory cells to the atherosclerotic lesion. Furthermore, the spleen also plays an important role in lipid homeostasis and immune-cell selection. Interestingly, clinical evidence from splenectomized subjects shows that they are more susceptible to developing pathologies, such as dyslipidemia and atherosclerosis due to the loss of immune selection. Although CVDs represent the leading cause of death worldwide, the mechanisms involving the spleen-atherosclerosis-heart axis cross-talk remain poorly characterized.

A Study on the Efficacy of Empirical Antibiotic Therapy for Splenectomized Children with Fever

Thalassemia represents a heterogeneous group of inherited diseases characterized by the lack or reduced production of hemoglobin β-chains. Many patients with thalassemia require splenectomy. What should be considered in the evaluation and management of candidates for splenectomy is to cover vaccination against infections such as pneumococci and the implementation of antibiotic prophylaxis. This study aimed to investigate the effect of the antibiotic type on the outcome of acute post-splenectomy infection in patients with thalassemia. This investigation is a retrospective cohort study. One hundred fifty medical records of hemoglobinopathy patients who underwent splenectomy were collected from the Ali-Asghar Hospital, Tehran, Iran. SPSS v. 20 and SAS v. 1.9 were used to analyze the data. A total of 150 patients that were vaccinated against post-splenectomy infections and were under antibiotic prophylaxis underwent splenectomy. The most commonly prescribed drugs were ceftriaxone or cefotaxime (132 cases, 88%), followed by ceftriaxone plus clindamycin (5.3%), ceftriaxone plus amikacin (3.3%), clindamycin (1.3%), vancomycin plus amikacin (0.7%), and others (1.3%). In terms of treatment outcomes, 143 cases (95.3%) were treated with the same antibiotics, and 4 (2.7%) experienced a changed antibiotic regimen with vancomycin. The results show that perceptions of treatment for fever in splenectomized children need to be changed, and most of them do not require hospitalization and initiation of broad-spectrum antibiotics such as vancomycin for initially refractory cases, and can only be treated with daily intravenous ceftriaxone.

Expert consensus on interventional therapy for traumatic splenic bleeding

This study aims to introduce the diagnosis and treatment processes of traumatic splenic bleeding and explain its emergency, medical, interventional, and surgical treatments. Furthermore, this study aims to summarize the indications and contraindications of splenic artery embolization, interventional procedures, and precautions of complications.

Audit of Post-Splenectomy Prophylaxis in a Single Tertiary Center in Slovenia: Where Are We and What Should Be Done?

Background: Patients who have had splenectomies are at increased risk for severe infections and overwhelming sepsis caused by pneumococci, meningococci, Haemophilus influenzae, and other encapsulated pathogens. Prophylactic measures are important to reduce mortality in this group; among them are vaccinations, antibiotic prophylaxis, and education. We performed a retrospective audit of post-splenectomy prophylactic measures, focusing on vaccinations and antibiotic prophylaxis coverage. Patients and Methods: We included 156 adult patients who had splenectomies between January 2010 and December 2018 in a study conducted at a single tertiary medical center. Data regarding vaccinations, antibiotic prophylaxis, and severe infections in the post-splenectomy period were obtained from medical records and supplemented by a patient-devised questionnaire. Results: Overall 121 of 156 (77.5%) of patients received a basic pneumococcal vaccination, although only 27 of 70 (38.6%) received re-vaccination after five years. Lower vaccination coverage was observed for meningococcal diseases and Haemophilus influenzae type b (Hib) disease with 57.0% (89/156) and 55.7% (87/156) vaccination coverage, respectively. A difference in pneumococcal vaccination coverage between patients after elective splenectomy (81/91; 89.0%) and non-elective splenectomy (40/65; 61.5%) was observed. However, no difference was observed among meningococcal and Hib vaccination coverage. Antibiotic prophylaxis was recommended to patients more frequently after elective splenectomy (41/82; 50.0%) than non-elective (16/56; 28.6%) yet after an elective splenectomy, patients discontinued the prophylaxis more often than those after a non-elective surgery. Overall, only 30 of 146 (20.5%) of patients received antibiotic prophylaxis over two years. In the observed period, 12.3% of patients suffered a severe infection. Conclusion: Our study shows that there is adequate basic pneumococcal vaccination coverage among patients after a splenectomy particularly after an elective splenectomy, but there is a lack of and an inadequate implementation of other prophylactic measures. There is an urgent need for an organized approach involving better education of healthcare practitioners as well as patients concerning the risk of asplenia. In addition, an improved long-term follow-up is needed including establishing a central registry for the asplenic patients in Slovenia.

Increased long-term pneumonia risk for the trauma-related splenectomized population - a population-based, propensity score matching study

BACKGROUND

Splenectomy is the life-saving treatment for high-grade spleen trauma. Splenectomized patients are at a significant infection risk. However, the trauma-induced splenectomy results in less incidence of postsplenectomy infection than the hematologic disorder. We conducted a large-scale study to identify the infection rate and management strategy in trauma-related splenic injuries.

METHODS

We included patients with the diagnosis of spleen injury in Taiwan from January 2003 to December 2013 by using the National Health Insurance Database and divided them into spleen preserved and splenectomized groups. The demographic factors including age, sex, hospital level, year of injury, trauma mechanism, associated injuries, whether injury severity score ≧16, and comorbidities were extracted. A 1:1 propensity score match was performed, and we analyzed the long-term outcome as the presence of infection-related disease (septicemia, pneumonia, and meningitis) after spleen trauma. The multivariate logistic regression analysis was used to identify the risk factor for each outcome.

RESULTS

During the 11 years included in this study, a total of 8,897 patients with spleen trauma were identified. A total of 3,520 (39.6%) patients were splenectomized, and 5,377 (60.4%) were spleen preserved. After propensity score matching, 3,099 pairs of patients were enrolled for further analysis. In univariate analysis, the incidence of pneumonia is significantly higher in the splenectomized group (8.5% vs 7.0%, P = .037). There was no significant difference in septicemia and meningitis between the 2 groups. In multivariate analysis, splenectomy is an independent risk factor for pneumonia in long-term follow-up.

CONCLUSION

Compared with the spleen preserved group, splenectomy is related to an increased likelihood of long-term pneumonia onset but not to an increase in the possibility of other infections.

Platelet phenotype and function in the absence of splenic sequestration (Review)

The spleen, in addition to its role in immunity, plays key roles in erythrocyte maintenance and platelet sequestration. Loss of the spleen via splenectomy occurs in approximately 6.4 to 7.1 per 100 000 people per year globally, commonly as a life-saving emergency procedure in trauma and a therapeutic procedure in hematological and hematological malignant conditions. It is associated with increased risk of life-threatening infection and thromboembolism, presumably via loss of splenic function, but the underlying mechanisms behind post-splenectomy thromboembolism are unclear. The splenectomized individual has a two-fold risk of thromboembolism as compared to non-splenectomized individuals and the risk of thromboembolism is elevated both post-operatively and in the longer term. Although those splenectomized for hematological conditions or hematological malignant conditions are at highest risk for thromboembolism, an increase in thromboembolic outcomes is also observed amongst individuals splenectomized for trauma, suggesting underlying disease state is only a partial factor. Although the physiological role of the splenic platelet pool on platelets is unclear, platelet changes after splenectomy suggest that the spleen may play a role in maintaining platelet quality and function. In hypersplenic conditions, sequestration can increase to sequester up to 72% of the total platelet mass. Following splenectomy, a thrombocytosis is commonly seen secondary to the loss of the ability to sequester platelets. Abnormal platelet quality and function have been observed as a consequence of splenectomy. These platelet defects seen after splenectomy may likely contribute to the increase in post-splenectomy thromboembolism. Here we draw upon the literature to characterize the post-splenectomy platelet and its potential role in post-splenectomy thromboembolism.

Post-splenectomy Sepsis: A Review of the Literature

The spleen is an intraperitoneal organ that performs vital hematological and immunological functions. It maintains both innate and adaptive immunity and protects the body from microbial infections. The removal of the spleen as a treatment method was initiated from the early 1500s for traumatic injuries, even before the physiology of spleen was properly understood. Splenectomy has therapeutic effects in many conditions such as sickle cell anemia, thalassemia, idiopathic thrombocytopenic purpura (ITP), Hodgkin’s disease, and lymphoma. However, it increases the risk of infections and, in some cases, can lead to a case of severe sepsis known as overwhelming post-splenectomy infection (OPSI), which has a very high mortality rate. Encapsulated bacteria form a major proportion of the invading organisms, of which the most common is Streptococcus pneumoniae. OPSI is a medical emergency that requires prompt diagnosis (with blood cultures and sensitivity, blood glucose levels, renal function tests, and electrolyte levels) and management with fluid resuscitation along with immediate administration of empirical antimicrobials. OPSI can be prevented by educating patients, vaccination, and antibiotic prophylaxis. This article summarizes the anatomy and physiology of the spleen and highlights its important functions. It primarily focuses on the pathophysiology of OPSI, its current management, and prevention strategies.