Infectious complications in asplenic hosts

Splenectomy is associated with sexual dysfunctions and decreased libido

The removal of the spleen due to disease or trauma may be followed by disorders due to the asplenism, including immunodeficiency, hematological and metabolic diseases, mainly dyslipidemia, which can lead to sepsis, pulmonary embolism and early death. Although patients frequently report sexual disinterest after splenectomy, this feature has been experimentally studied only in a translational investigation performed by the same group of this work. To study libido and other sexual functions after the complete removal of the spleen in humans. This study was performed on 60 healthy adults, 30 men and 30 women, after more than 1 year of total splenectomy to treat isolated splenic trauma. The International Index of Erectile Function was applied to men and the Female Sexual Function Index to women. The analysis compared the responses obtained in the periods before and after the splenectomy. Laboratory tests with hematological and biochemical analyses, including sex hormones, were performed in all patients. The pre- and postoperative results were compared in each group using the paired t-test, with each patient being his or her own control and with significance to p < 0.05. A decrease in libido and an increase in sexual dysfunction was observed after splenectomy in all men and women, p < 0.001. All postoperative laboratory tests showed normal values in both genders. Asplenia is associated with a marked decrease in libido and intense sexual dysfunction in both men and women, with normal hematological and biochemical laboratory tests, including hormonal exams.

Reduction in pregnancies and litters in mice couples with splenectomized male

PURPOSE

The spleen is relevant in blood purification, hematopoiesis, metabolism, and immune response to antigens, in addition to the storage and control on the release of metals and amino acids. Its functions concerning reproduction characteristics are still unknown. The objective was to study the influence of splenectomies on reproduction.

METHODS

This study analyzed 25 mice couples, distributed into five groups: group 1 - control, no surgery: group 2 - control, submitted to laparotomy and laparorrhaphy only; group 3 - splenectomy in male mice; group 4 - splenectomy in female mice; group 5 - splenectomy in male and female mice. The animals were studied as regards the number of gestations and offspring generated in each gestation.

RESULTS

A decrease in both the number of gestations and the number of offspring was verified in the male mice that had received a splenectomy when coupled with normal female mice. It is important to emphasize lower reproduction level when paired asplenic males with normal females, otherwise, the couples in which both mice had been splenectomized did not present change in the reproduction pattern.

CONCLUSIONS

A reduction in the number of pregnancies and litters occurs in mice couples when the male mice were previously splenectomized.

A Complicated Case of Vaccine Refusal

Parents in the United States have a legal right to refuse vaccination for their children. There are, however, special circumstances under which the state may compel vaccination against parental wishes. In this Ethics Rounds article, we present the case of a young boy with sickle cell disease who was partially vaccinated against encapsulated bacteria and the ethics of whether to compel complete vaccination before splenectomy.

Potential role of Howell-Jolly bodies in identifying functional hyposplenism: a prospective single-institute study

Although patients with cancer and immunosuppression are at a risk of functional hyposplenism, how to detect it promptly remains unclear. Since hyposplenism allows erythrocytes with nuclear remnants (Howell-Jolly bodies [HJBs]) to appear in the peripheral blood, HJB detection by a routine microscopic examination may help identify patients with functional hyposplenism. This prospective study was thus performed to determine the underlying diseases in patients who presented with HJBs. Of 100 consecutive patients presenting with HJBs, 73 had a history of splenectomy. The remaining 27 had hematologic cancer (n = 6, 22%), non-hematologic cancer (n = 8, 30%), hepatic disorders (n = 4, 15%), premature neonates (n = 3, 11%), hemolytic anemia (n = 2, 7%), autoimmune disorders (n = 2, 7%) and miscellaneous diseases (n = 2, 7%), and their prior treatments included chemotherapy (n = 8, 30%), steroids (n = 7, 26%) and molecular-targeted therapy (n = 3, 11%). Among the 27 patients, 22 had computed tomography scans available: 3 (14%) had underlying diseases in the spleen, and the remaining 19 (86%) were all found to have a decreased splenic volume, including 11 (50%) with more than 50% of the ideal value. The present findings suggest that HJB detection identifies patients with potentially functional hyposplenism who should receive appropriate interventional treatment, such as vaccination and prophylactic antibiotics.

Indian Antimicrobial Prescription Guidelines in Critically Ill Immunocompromised Patients

How to cite this article: Kulkarni AP, Sengar M, Chinnaswamy G, Hegde A, Rodrigues C, Soman R, Khilnani GC, Ramasubban S, Desai M, Pandit R, Khasne R, Shetty A, Gilada T, Bhosale S, Kothekar A, Dixit S, Zirpe K, Mehta Y, Pulinilkunnathil JG, Bhagat V, Khan MS, Narkhede AM, Baliga N, Ammapalli S, Bamne S, Turkar S, Bhat KV, Choudhary J, Kumar R, Divatia JV. Indian Journal of Critical Care Medicine 2019;23(Suppl 1): S64-S96.

Protection Against Invasive Infections in Children Caused by Encapsulated Bacteria

The encapsulated bacteria Streptococcus pneumoniae, Neisseria meningitis, Haemophilus influenzae, and Streptococcus agalactiae (Group B Streptococcus) have been responsible for the majority of severe infections in children for decades, specifically bacteremia and meningitis. Isolates which cause invasive disease are usually surrounded by a polysaccharide capsule, which is a major virulence factor and the key antigen in protective protein-polysaccharide conjugate vaccines. Protection against these bacteria is largely mediated via polysaccharide-specific antibody and complement, although the contribution of these and other components, and the precise mechanisms, vary between species and include opsonophagocytosis and complement-dependent bacteriolysis. Further studies are required to more precisely elucidate mechanisms of protection against non-type b H. influenzae and Group B Streptococcus.

A cohort study to evaluate infection prevention protocol in pediatric trauma patients with blunt splenic injury in a Dutch level 1 trauma center

PURPOSE

Asplenic patients are at increased risk for the development of overwhelming postsplenectomy infection (OPSI) syndrome. It is believed that adequate immunization, antimicrobial prophylaxis, as well as appropriate education concerning risks on severe infection lead to the decreased incidence of OPSI. The aim of this study was to analyze the methods used to prevent OPSI in trauma patients splenectomized before the age of 18.

PATIENTS AND METHODS

A retrospective, single-center study of all pediatric patients sustaining blunt splenic injury (BSI) managed at our level 1 trauma center from January 1979 to March 2012 was performed. A questionnaire was sent to all the included patients to determine the level of knowledge concerning infection risks, the use of antibiotics, and compliance to vaccination recommendations. Furthermore, we investigated whether the implementation of guidelines in 2003 and 2011 resulted in higher vaccination rates.

RESULTS

We included 116 children with BSI. A total of 93 completed interviews were eligible for analysis, resulting in a total response rate of 80% and 1,116 patient years. Twenty-seven patients were splenectomized, and 66 patients were treated by a spleen preserving therapy (including embolization). Only two out of 27 splenectomized patients were adequately vaccinated, five patients without a spleen used prophylactic antibiotics, and about half of the asplenic patients had adequate knowledge of the risk that asplenia entails. A total of 22/27 splenectomized patients were neither adequately vaccinated nor received prophylactic antibiotics. There was no OPSI seen in our study population during the 1,116 follow-up years.

CONCLUSION

The vaccination status, the level of knowledge concerning prevention of an OPSI, and the use of prophylactic antibiotics are suboptimal in pediatric patients treated for BSI. Therefore, we created a new follow-up treatment guideline to have adequate preventive coverage to current standards for these patients.

Enhancing problem list documentation in electronic health records using two methods: the example of prior splenectomy

BACKGROUND

Quality improvement professionals often choose between patient-specific interventions, like clinical decision support (CDS), and population-based interventions, like registries or care management. In this paper, we explore the synergy of these two strategies, targeting the problem of procedure documentation for patients with a history of splenectomy.

METHODS

We developed a population health documentation (PHD) intervention and a CDS intervention to improve splenectomy documentation within our electronic health record. Rates of splenectomy documentation were collected before and after the implementation of both interventions to assess their impact on the rate of procedure documentation.

RESULTS

Both the PHD and CDS interventions led to statistically significant (p<0.001) increases in the baseline rate of splenectomy documentation of 27.4 documentations per month. During the PHD intervention, 444.7 splenectomies were documented per month, while 40.8 splenectomies per month were documented during the CDS intervention.

DISCUSSION

Both approaches were successful, with the PHD intervention leading to a larger number of incremental procedure documentations, in batches, and the CDS intervention augmenting procedure documentation on an ongoing basis. Our results suggest that population health and CDS strategies complement each other and, where possible, should be used in conjunction.

CONCLUSIONS

PHD and CDS strategies may best be used in conjunction to create a symbiotic relationship in which current problem and procedure documentation gaps are closed using PHD strategies, while new gaps are prevented through ongoing CDS interventions.

The Asplenic Patient: Post-Insult Immunocompetence, Infection, and Vaccination

BACKGROUND

Splenic injury can occur through multiple mechanisms and may result in various degrees of residual immunocompetence. Functionally or anatomically asplenic patients are at higher risk for infection, particularly with encapsulated bacteria. Vaccination is recommended to prevent infection with these organisms; however, the recommendations are routinely updated, and vaccine selection and timing are complex.

METHODS

Review of the pertinent English-language literature, including the recommendations of the U.S. Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices.

RESULTS

Overwhelming post-splenectomy infection is associated with high morbidity and mortality rates. Patients requiring splenectomy for trauma-related injury appear to be at lower risk for infection than those undergoing splenectomy for a hematologic or oncologic indication. Initial vaccination is dependent on immunization history but generally should consist of the 13-valent pneumococcal conjugate, quadrivalent meningococcal conjugate, meningococcal serogroup B, and Haemophilus influenzae serotype b (Hib) vaccines. Antimicrobial prophylaxis for certain asplenic patients, such as children under the age of five y, may be indicated.

CONCLUSION

Immunization remains a key measure to prevent overwhelming post-splenectomy infection. Consideration of new recommendations and indications, possible interactions, and timing remains important to including optimal response to the vaccines.

Recommended vaccinations for asplenic and hyposplenic adult patients

Asplenic or hyposplenic (AH) individuals are particularly vulnerable to invasive infections caused by encapsulated bacteria. Such infections have often a sudden onset and a fulminant course. Infectious diseases (IDs) incidence in AH subjects can be reduced by preventive measures such as vaccination. The aim of our work is to provide updated recommendations on prevention of infectious diseases in AH adult patients, and to supply a useful and practical tool to healthcare workers for the management of these subjects, in hospital setting and in outpatients consultation. A systematic literature review on evidence based measures for the prevention of IDs in adult AH patients was performed in 2015. Updated recommendations on available vaccines were consequently provided. Vaccinations against S. pneumoniae, N. meningitidis, H. influenzae type b and influenza virus are strongly recommended and should be administered at least 2 weeks before surgery in elective cases or at least 2 weeks after the surgical intervention in emergency cases. In subjects without evidence of immunity, 2 doses of live attenuated vaccines against measles-mumps-rubella and varicella should be administered 4-8 weeks apart from each other; a booster dose of tetanus, diphtheria and pertussis vaccine should be administered also to subjects fully vaccinated, and a 3-dose primary vaccination series is recommended in AH subjects with unknown or incomplete vaccination series (as in healthy people). Evidence based prevention data support the above recommendations to reduce the risk of infection in AH individuals.

Phagocytic function of lower spleen pole and autogenous splenic implants in rats

PURPOSE

To investigate whether there are differences between the phagocytic function of the remaining lower spleen pole after subtotal splenectomy and autogenous splenic implants.

METHODS

Thirty-six male Wistar rats, weighting 364 ± 60g were used. They were subjected to subtotal splenectomy preserving the lower spleen pole and to autogenous splenic implant in the greater omentum. Its viability was assessed microscopically. Phagocytic function was assessed by splenic uptake of the radioisotope-labeled colloid and by macrophages counting.

RESULTS

The viability of the autogenous splenic implant and of the lower spleen pole was found in 33 animals, with no difference between them. The weight of the implants was higher than the lower pole of animals from groups G1, G7, G30, G60 and G120. The implants phagocytic function by radioisotope uptake was higher than the lower pole in G7 and G120 groups and it did not differ from the other groups. The number of macrophages was higher in G1, G60, G90 and G120 and did not differ from the other groups.

CONCLUSION

Until the 16th week, the phagocytic function was more pronounced in autogenous splenic implants when compared with the lower spleen pole, but it became similar thereafter.

Capnocytophaga canimorsus: an emerging cause of sepsis, meningitis, and post-splenectomy infection after dog bites

Newly named in 1989, Capnocytophaga canimorsus is a bacterial pathogen found in the saliva of healthy dogs and cats, and is transmitted to humans principally by dog bites. This review compiled all laboratory-confirmed cases, animal sources, and virulence attributes to describe its epidemiology, clinical features, and pathogenesis. An estimated 484 patients with a median age of 55 years were reported, two-thirds of which were male. The case-fatality rate was about 26%. Its clinical presentations included severe sepsis and fatal septic shock, gangrene of the digits or extremities, high-grade bacteremia, meningitis, endocarditis, and eye infections. Predispositions were prior splenectomy in 59 patients and alcoholism in 58 patients. Dog bites before illness occurred in 60%; additionally, in 27%, there were scratches, licking, or other contact with dogs or cats. Patients with meningitis showed more advanced ages, higher male preponderance, lower mortality, and longer incubation periods after dog bites than patients with sepsis (p < 0.05). Patients with prior splenectomy presented more frequently with high-grade bacteremia than patients with intact spleens (p < 0.05). The organism possesses virulence attributes of catalase and sialidase production, gliding motility, cytotoxin production, and resistance to killing by serum complement due to its unique lipopolysaccharide. Penicillin is the drug of choice, but some practitioners prefer third-generation cephalosporins or beta-lactamase inhibitor combinations. C. canimorsus has emerged as a leading cause of sepsis, particularly post-splenectomy sepsis, and meningitis after dog bites.

Functional hyposplenism is an important and underdiagnosed immunodeficiency condition in children

AIM

Few studies have focused on paediatric hyposplenism/asplenism, in which splenic phagocytic activity is diminished or absent in an anatomically present spleen. This study aimed to evaluate clinical findings, laboratory tests and prognosis of children with functional hyposplenism/asplenism.

METHODS

The study group comprised 74 children who had liver/spleen technetium-99m sulphur colloid scintigraphy from 2002 to 2008. Information collected included demographic features, background diseases, blood smear findings, indications for scintigraphy and outcome. Children with functional hyposplenism were followed until 2012.

RESULTS

We found that 34 patients had functional hyposplenism/asplenism. The main indications for scintigraphy in the hyposplenic patients were persistent thrombocytosis and recurrent infections. Associated conditions included immunodeficiencies, autoimmune diseases, malignancies and genetic disorders. Main infections were sinopulmonary infections, bacteraemia and sepsis. The major pathogens were Streptococcus pneumoniae and Haemophilus influenza group A. There was no correlation between the presence of Howell-Jolly bodies in blood smear with clinical disease severity or scintigraphic findings. Repeated scintigraphy showed spontaneous normalisation in 40% of patients.

CONCLUSION

Functional hyposplenism is an important and underdiagnosed immunodeficiency condition in children, associated with various clinical conditions including prolonged unexplained thrombocytosis, immune deficiency and autoimmunity. Technetium-99m sulphur colloid scintigraphy is the method of choice for evaluating splenic function.

Cryptococcal meningitis in patients with autoimmune hemolytic anemia

To summarize the epidemiology, clinical features, treatment, and outcome of cryptococcal meningitis (CM) in autoimmune hemolytic anemia (AIHA) patients and to provide a reference for the prevention and control of AIHA complicated with CM, we evaluated five cases of CM in patients with AIHA treated in our hospital from 2003 to 2013 and eight related foreign cases. All of the clinical isolates were Cryptococcus neoformans var. grubii and grouped into the VNI genotype and serotype A. The clinical features exhibit significant features. Headache, nausea, and fever are common symptoms of AIHA complicated with CM. The early clinical manifestations lack specificity, which may lead to delayed diagnosis and treatment. Long-term use of prednisone (≥15 mg day(-1)), poor control of anemia, and splenectomy are risk factors for AIHA complicated with cryptococcal infection. The combination of intravenous amphotericin B and oral 5-fluorocytosine remains the preferred treatment for AIHA complicated with CM.

Blood clearance of Howell-Jolly bodies in an experimental autogenic splenic implant model

BACKGROUND

Autogenic splenic implant (ASI) is one of the few alternatives for preservation of splenic tissue when total splenectomy is inevitable. The aim of this study was to determine the morphological and functional regeneration of ASIs, as indicated by the clearance of Howell-Jolly (HJ) bodies, in an experimental model.

METHODS

Ninety-nine male Wistar rats were divided into three groups: sham-operated (group 1), total splenectomy alone (group 2), and total splenectomy combined with ASI (group 3). Animals in group 3 were further allocated to nine subgroups of nine rats each, and analysed at different time points (1, 4, 8, 12, 16, 20, 24, 28 and 32 weeks after surgery). Blood smears were prepared at predetermined times for detection of HJ bodies. Morphological regeneration of tissue in the ASI was analysed by histology.

RESULTS

At 1 week, the regenerated mass corresponded to about 7 per cent of the tissue implanted, reaching approximately 54 per cent at 24 weeks. The HJ body levels were increased in groups 2 and 3 until 8 weeks after surgery, following which levels in the ASI group became similar to those in the sham-operated group. HJ bodies were difficult to detect when a level of 22.5 per cent of regenerated ASI mass was reached.

CONCLUSION

Functional regeneration of ASIs occurred from 8 weeks after surgery. When 22.5 per cent of regenerated ASI mass was reached almost no HJ bodies could be observed in the bloodstream, resembling a spleen in situ.

SURGICAL RELEVANCE

Splenectomy has been practised routinely, both in the emergency setting and as a therapeutic elective procedure. There is a correlation between asplenia/hyposplenia and the occurrence of fulminant sepsis, underlining the importance of developing surgical methods for preserving splenic function. Both clinical and experimental studies have shown at least partial morphological and functional regeneration of autogenic splenic implants (ASIs). Experimental studies investigating the immunoprotective effect of ASIs, based mostly on exposure of animals to various bacteria, have demonstrated that ASIs can increase the rate of bacterial clearance and decrease mortality from sepsis. Clinical studies have shown their ability to remove colloidal substances and altered erythrocyte corpuscular inclusions, such as Howell-Jolly, Heinz and Pappenheimer bodies, from the bloodstream. In this experimental study the functional and morphological regeneration of ASIs was studied over time in rats.

Intravascular hemolysis, vascular endothelial cell activation and thrombophilia in splenectomized patients with hemoglobin E/β-thalassemia disease

The relationship between asplenia and thrombophilia in β-thalassemia disease patients is not yet completely understood. One hundred and ten adult hemoglobin (Hb) E/β-thalassemia (E/β-Thal) disease outpatients, dichotomized according to the presence or absence of the spleen, were prospectively studied for evidence of intravascular hemolysis (IVH) and vascular endothelial cell (EC) activation. Biomarkers of IVH (serum cell-free Hb), EC [soluble E-selectin (sE-selectin) and soluble vascular cell adhesion molecule 1 (sVCAM-1)], platelet and EC [soluble P-selectin (sP-selectin)], inflammation [high-sensitivity C-reactive protein (hs-CRP)], and coagulation [thrombin-antithrombin complexes (TAT)] activation, as well as other selected blood tests were determined. The 61 splenectomized patients had a more severe hemolytic disease and higher levels of cell-free Hb and ferritin (p = 0.003), sE-selectin, sP-selectin, hs-CRP, and TAT (p < 0.05). However, serum levels of sVCAM-1 were not different between the two groups. The findings suggested IVH and EC activation. Together with chronic iron overload and chronic low-grade inflammation activation, the findings extend our understanding of the mechanism of thrombophilia in splenectomized E/β-Thal disease patients.

Vaccination considerations in the asplenic patient

Overwhelming postsplenectomy sepsis is a rare but devastating and often lethal disease. Although vaccines are available, their proper use may be questioned. Standardization of protocols for the immunization of asplenic patients should be universal, thus, likely improving on their use. This article reviews the vaccines to be administered to the asplenic patient.

Lung abscess presenting as tension pyopneumothorax in a gastrointestinal cancer patient

We report a surgical case of tension pyopneumothorax in a patient who was receiving chemotherapy for esophageal cancer. A 68-year-old man who had undergone total gastrectomy with splenectomy for gastric cancer and was receiving chemotherapy for esophageal cancer was presented to our hospital with dyspnea. Left tension pyopneumothorax was diagnosed, and he received left lower lobectomy after pleural drainage. His postoperative course was uneventful, and he is alive without any cancer recurrences 5 years after the lobectomy. Once tension pyopneumothorax has developed from lung abscess, emergent lobectomy may be a useful option to prevent lethal aspiration pneumonia.

Changes in gastrosplenic circulation and splenic function after distal pancreatectomy with spleen preservation and splenic vessel excision

INTRODUCTION

Distal pancreatectomy with spleen preservation and splenic vessel excision is a commonly used technique. However, it produces significant gastrosplenic circulation and splenic function changes.

PURPOSE

The aim of this work was to determine the immediate consequences on gastrosplenic circulation, late consequences on splenic function, and development of varicose veins.

METHODS

Thirty-five patients with pancreatic tumors and anatomical feasibility were included. Preoperative splenic circulation was evaluated by dynamic contrast-enhanced computed tomography (CT) scans. Early splenic perfusion was assessed by CT 7 days after surgery and late changes in gastrosplenic circulation 6 months after surgery. Varicose veins were evaluated by CT and endoscopy 6 months after surgery. Pitted cells and Howell-Jolly bodies were used as markers of splenic function. Postoperatory findings included changes in splenic perfusion 7 days and 6 months after surgery, development of varicose veins on CT scans and endoscopy, and detection of markers of splenic hypofunction on blood smears.

RESULTS AND CONCLUSION

Seven days after surgery, 63% of patients had some degree of splenic hypoperfusion, and 6 months after surgery, 83% of patients had normal perfusion. CT scans showed varices in 26 patients, and endoscopy revealed varicose veins in 11. Two patients experienced bleeding; markers of splenic hypofunction were found in 59% of cases.

Hyposplenism: A comprehensive review. Part II: Clinical manifestations, diagnosis, and management

In the first part of this review, we described the physiological basis of splenic function and hypofunction. We also described the wide spectrum of diseases that can result in functional hyposplenism. In the second part of this review, we will be discussing the clinical picture, including complications, diagnostic methods, and management of hyposplenism.

Immunization in special populations

In summary, immunizations in special populations require understanding the underlying disease and how it might affect the immune system's ability to mount an antibody response to vaccines or predispose certain patient populations to developing certain serious infections. There is still a great need for research on the optimal timing of vaccines after transplants, how to assess protection and development of a protective antibody response after immunization, and whether certain groups (eg, HIV) need to be revaccinated after a certain amount of time if their antibody levels decline. In addition, there are limited data on efficacy of the newer vaccines in these special patient populations, which also requires further investigation.

Prevention of infections associated with combat-related thoracic and abdominal cavity injuries

Trauma-associated injuries of the thorax and abdomen account for the majority of combat trauma-associated deaths, and infectious complications are common in those who survive the initial injury. This review focuses on the initial surgical and medical management of torso injuries intended to diminish the occurrence of infection. The evidence for recommendations is drawn from published military and civilian data in case reports, clinical trials, meta-analyses, and previously published guidelines, in the interval since publication of the 2008 guidelines. The emphasis of these recommendations is on actions that can be taken in the forward-deployed setting within hours to days of injury. This evidence-based medicine review was produced to support the Guidelines for the Prevention of Infections Associated With Combat-Related Injuries: 2011 Update contained in this supplement of Journal of Trauma.

Clinical spectrum of serious bacterial infections among splenectomized patients with hemoglobinopathies in Israel: a 37-year follow-up study

PURPOSE

Patients with hemoglobinopathies who undergo splenectomy are at risk for invasive infections. The aim of this investigation was to present the clinical spectrum of infections in splenectomized patients.

METHODS

The study cohort comprised 54 splenectomized patients with beta-thalassemia (β-thalassemic) and sickle cell disease. The incidence of serious invasive bacterial infections was recorded. All patients received pneumococcal vaccine and all received oral prophylactic penicillin.

RESULTS

A total of 22 episodes of serious bacterial infections were identified in 19 patients among the study cohort of 54 splenectomized patients (35%). The clinical spectrum included sepsis (10 patients), bacteremia (8), liver abscess (1), forearm abscess (1), and urinary tract infection (2). The most frequent pathogens were Escherichia coli (8 cases), Steptococcus pneumoniae (5), and Campylobacter (2). 22 patients with β thalassemia died during the study period: 6 due to bacterial infection and 18 due to cardiomyopathy. The time elapsed between splenectomy and S. pneumoniae infection was significantly shorter than that between splenectomy and infections caused by other pathogens (18 ± 14 vs. 115 ± 93 months, respectively; p = 0.035).

CONCLUSIONS

Splenectomized patients with β thalassemia and sickle cell disease are predisposed to severe infections, with the majority of these infections being caused by Gram-negative microorganisms. The attending physician(s) should take these findings into consideration when deciding upon an empiric antibiotic treatment for splenectomized patients who present with fever or sepsis.

Subtotal laparoscopic splenectomy in rats with preservation of the inferior pole

Purpose: To evaluate the feasibility and safety of subtotal splenectomy by laparoscopy with inferior pole preservation and to determine the viability of the splenic remnant. Methods: Twenty male Wistar rats weighing between 365 g and 474 g (mean 417.92 ± 36.15g SD) were operated and randomly assigned to two groups : Group 1 rats were killed on postoperative day 10 (n = 10), and Group 2 on the postoperative day 80 (n = 10). Both the inferior splenic pole and the superior part of the spleen, which was used as a control to measure inferior pole viability, were weighed and morphologically examined. Results: The technique was feasible in all cases. There were two postoperative deaths on immediate postoperative and one not well defined. The average weight percentage of the inferior pole, measured indirectly on the 10th day, was 53.67% ± 11.59% and on the 80th day was 62.69% ± 6.89%. The inferior pole was necrotic, with abscess formation in one case (5.9%) and appeared normal in all other cases. Microscopy showed features that were compatible with normality. Conclusions: Subtotal splenectomy with preservation of the inferior pole by laparoscopy was feasible and safety. The lower splenic pole was viable in 94.1% of animals.

Survivorship: childhood cancer survivors

Late effects of therapy for childhood cancer are frequent and serious. Fortunately, many late effects are also modifiable. Proactive and anticipatory risk-based care can reduce the frequency and severity of treatment-related morbidity. The primary care clinician should be an integral component in risk-based care of survivors. Continued communication between the "late effects" staff at the cancer center and the primary care clinician is essential for optimum care of this high-risk population.

Infections in thalassemia and hemoglobinopathies: focus on therapy-related complications

The clinical approach to thalassemia and hemoglobinopathies, specifically Sickle Cell Disease (SCD), based on transfusions, iron chelation and bone marrow transplantation has ameliorated their prognosis. Nevertheless, infections still may cause serious complications in these patients. The susceptibility to infections in thalassemia and SCD arises both from a large spectrum of immunological abnormalities and from exposure to specific infectious agents. Four fundamental issues will be focused upon as central causes of immune dysfunction: the diseases themselves; iron overload, transfusion therapy and the role of the spleen. Thalassemia and SCD differ in their pathogenesis and clinical course. It will be outlined how these differences affect immune dysfunction, the risk of infections and the types of most frequent infections in each disease. Moreover, since transfusions are a fundamental tool for treating these patients, their safety is paramount in reducing the risks of infections. In recent years, careful surveillance worldwide and improvements in laboratory tests reduced greatly transfusion transmitted infections, but the problem is not completely resolved. Finally, selected topics will be discussed regarding Parvovirus B19 and transfusion transmitted infections as well as the prevention of infectious risk postsplenectomy or in presence of functional asplenia.

Role of secondary lymphoid tissues in primary and memory T-cell responses to a transplanted organ

Secondary lymphoid tissues are the hub of adaptive immune responses wherein rare cognate lymphocytes encounter dendritic cells bearing antigen from peripheral tissues and differentiate into effector and memory cells that eliminate antigen. It is accepted that immune responses against microbial and tumor antigens are initiated within secondary lymphoid tissues. There is less agreement on whether the same principle applies to immune responses to a transplanted organ because an allograft expresses foreign major histocompatibility complex and contains donor antigen presenting cells that could activate T cells directly in situ leading to rejection. Recent studies confirm that although naïve T cells can be primed within the allograft, their differentiation to effect rejection is dependent on secondary lymphoid tissues. Antigen-experienced memory T cells, unlike Naïve T cells, function largely independent of secondary lymphoid tissues to cause allograft rejection. In an alloimmune response, secondary lymphoid tissues support not only immune activation but also immune regulation essential for allograft survival. Here, we will review recent findings and discuss the role of secondary lymphoid tissues in primary and memory alloimmune responses.

Introducing mediterranean journal of hematology and infectious diseases

Mediterranean Journal of Hematology and Infectious Diseases (MJHID) is a new open access, peer-reviewed, online journal, which encompasses different aspects of clinical and translational research providing an insight into the relationship between acute and chronic infections and hematological diseases. MJHID will be a topical journal on subjects of current importance in clinical haematology and infectious diseases. Every issue should have, beside the editor in chief, a guest editor. Both editor in chief and guest editor provide to invite experts in the selected topic to performe a complete update of the arguments readily available for practising phisicians. The journal will have also a section devoted to original papers, case reports and letters to editor and Editorial comment mostly focusing on the arguments treated in the previous topical issues.

Survivorship after childhood, adolescent, and young adult cancer

Survivors of pediatric and young adult cancers face lifetime risks associated with their cancer therapy, with a significant proportion at risk for serious morbidity and premature mortality. This growing population has complex healthcare needs. In this article, we present 4 case vignettes to illustrate specific risks of cancer therapy and describe a model for the care of survivors of childhood, adolescent, and young adult cancer.

Staphylococcus aureus infection after splenectomy and splenic autotransplantation in BALB/c mice

Splenectomy results in an increased risk of sepsis. The autogenous transplant of the spleen is an option for preserving splenic functions after total splenectomy. In this study, the capacity of animals undergoing autogenous spleen transplantation to respond to Staphylococcus aureus infection was investigated. BALB/c mice were divided into three groups: splenectomy followed by autotransplantation in the retroperitonium (AT), splenectomized only (SP) and operated non-splenectomized sham control (CT). Thirty days after surgery the mice were infected intravenously with S. aureus. Splenectomized mice had a higher number of colony-forming units (CFU) of S. aureus in liver and lungs in comparison with either AT or with CT mice (P < 0.05). Higher CFU numbers in lung of SP mice correlated with elevated production of interleukin-10 associated with a lower production of interferon-gamma and tumour necrosis factor-alpha. However, systemically, the level of tumour necrosis factor-alpha was higher in the SP group than in CT or AT. Lower titres of specific anti-S. aureus immunoglobulin (Ig)M and IgG1 were observed 6 days after infection in SP mice in comparison either with the AT or CT groups. Thus, splenectomy is detrimental to the immune response of BALB/c mice against infection by S. aureus which can be re-established by autogenous implantation of the spleen.

A 52-year-old man with malaise and a petechial rash

BACKGROUND

Capnocytophaga canimorsus is a Gram-negative, fusiform, rod-shaped organism that is part of the normal oral flora of dogs, cats, and other animals. A significant number of Emergency Department (ED) patients are surgically or functionally asplenic and may be at marked risk for overwhelming post-splenectomy infection (OPSI). OPSI has a mortality rate estimated to be up to 70%. The risk of sepsis is estimated to be 30-60 times greater after splenectomy, and C. canimorsus is one of the organisms that can cause catastrophic OPSI.

OBJECTIVES

To describe a case of C. canimorsus septic shock in a post-splenectomy patient and review the epidemiology of OPSI, the role of the spleen in protecting the body from infection, and the potential role of early goal-directed therapy in the resuscitation of patients with OPSI.

CASE REPORT

A 52 year-old man with a past medical history significant for idiopathic thrombocytopenic purpura (status post-splenectomy), and non-Hodgkin lymphoma (treated for cure), was brought to the ED with the chief complaints of light-headedness, malaise, and a rapidly spreading rash. He was found to be hypotensive, tachycardic, and tachypneic, and had a marked lactic acidosis. He was aggressively resuscitated with large volume fluid resuscitation and treated empirically with broad-spectrum antibiotics for septic shock of unclear etiology. His clinical course was complicated by acute lung injury and renal failure. Blood cultures grew C. canimorsus; he was extubated on hospital day 7 and discharged home several days later in good condition.

CONCLUSIONS

Patients status-post-splenectomy are at greatly increased risk for infection from encapsulated organisms and other organisms, including C. canimorsus, which is part of the normal oral flora of dogs, cats, and other animals. It can be spread to humans by bites, scratches, or less invasive forms of animal-human contact. C. canimorsus infection can lead to OPSI. Early recognition and aggressive clinical management, including early goal-directed therapy and rapid administration of antibiotics, may minimize the morbidity and mortality of this condition and other etiologies of severe sepsis and septic shock.

Immune response to the 7-valent pneumococcal conjugate vaccine in 30 asplenic children

The aim of the study was to determine the concentration of pneumococcal antibodies after a dose of 7-valent pneumococcal conjugate vaccine (PCV7) in 30 asplenic children between 4 months and 19 years of age. Fifteen children had received pneumococcal polysaccharide vaccine (PPV) approximately 5 years prior to vaccination with PCV7. The antibody concentrations against serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F were measured by ELISA before and after the PCV7 vaccination. Before vaccination with PCV7, the antibody concentrations were similar in children who had or had not received PPV previously. A dose of PCV7 stimulated a good immune response in asplenic patients. Prior immunization with PPV did not affect the antibody concentration after the vaccination with PCV7. In conclusion, asplenic children vaccinated with PPV may need revaccination with PPV earlier than the recommended 3-5 years after the first dose. PCV7 induces a satisfactory immune response in asplenic patients and should be considered as an alternative vaccine in that patient group.

Ciliary syndromes and treatment

Abnormal visceral patterning has been known for centuries. However, it has not been associated with ciliary dysfunction until recently. Overlapping clinical entities including situs inversus, certain infertility disorders, as well as chronic respiratory infections have their roots in abnormal ciliary function. Current research focuses on causative factors and genes involved in signal transduction pathways that define ciliary function and structure, as well as treatment. In this review, attempts are made to outline selected, yet key topics related to ciliary function in health and disease.

Invasive Cryptococcus neoformans infection in an asplenic patient

Individuals who are asplenic or have impaired splenic function are at increased risk of developing life-threatening infections, especially due to encapsulated bacteria. This risk is higher in children, but adults can also develop fulminant infection or "post splenectomy sepsis" (PSS). Cryptococcus neoformans is an encapsulated yeast usually causing infection in immunocompromised patients. In a recent review of cryptococcal infection in HIV-negative patients, splenectomy was reported to be a risk factor for infection in 3% of cases. Detailed case reports are lacking. Here we report a case of disseminated C. neoformans infection in a patient who had a splenectomy performed for warm autoantibody haemolytic anaemia some months before he presented with signs and symptoms of meningitis. This report aims to raise awareness of the possibility of C. neoformans infection in asplenic patients.

The Prevention and Management of Infections in Children with Asplenia or Hyposplenia

Overwhelming sepsis remains a significant complication of asplenia and hyposplenia. The mainstays of prevention are education, immunization, and prophylactic antibiotics. Evidence to base recommendation and guidelines is lacking. Such decisions as the specific immunizations required, the timing of immunizations, the duration of antibiotic prophylaxis, and the prevention of overwhelming postsplenectomy sepsis in children undergoing splenectomy are often empiric. This article reviews the current literature on the prevention and management of severe infections in children with underlying asplenia or hyposplenia.

Prevención de la sepsis en pacientes esplenectomizados

Although the high mortality rate from infectious causes in asplenic patients has been well known since the beginning of the twentieth century, rates of antibiotic prophylaxis in these patients continue to be worryingly low. Consequently, we reviewed the causes of these high mortality rates with a view to recommending preventive measures. The attitude to prophylaxis in these patients depends on age and the cause of splenectomy both in vaccination and antibiotic prophylaxis. The immune status of these patients is decisive in antibiotic prophylaxis, as this treatment will differ in patients splenectomized after a traffic accident and in those splenectomized for lymphoma.

Time lapse and comorbidities influence patient knowledge and pursuit of medical care after traumatic splenectomy

BACKGROUND

There is insufficient knowledge of infectious risk in patients after splenectomy; minimal data exists specifically for trauma patients. This study evaluated patient knowledge and practices regarding infection risk after traumatic splenectomy. Our hypothesis was that patients with poor knowledge regarding their asplenic state would be less likely to pursue medical care in the event of an illness than those with good knowledge.

METHODS

Non-randomized, cohort study of all posttraumatic splenectomy patients < or =11 years after injury in 2 rural trauma centers. Patients received a validated questionnaire; weighted responses determined knowledge about infection risks and appropriate follow-up actions.

RESULTS

Fifty-four percent of patients responded to the questionnaire. Overall, 47% of responders were identified as having adequate knowledge regarding infectious risk, and only 28% would pursue appropriate medical care. Of patients with adequate knowledge, 42% were more likely to pursue appropriate care versus 15% of patients with inadequate knowledge (p = 0.06). Patients with adequate knowledge were more likely to receive an annual influenza vaccine (p = 0.03) and contact their provider with fewer symptoms (p = 0.03). Logistic regression revealed significant interactions between knowledge and presence of comorbidities (p = 0.04). Focusing on patients with poor knowledge and absence of comorbidities, none would engage in appropriate action in the event of illness (p < 0.01). A longer time since injury, >3 years, was associated with a diminished likelihood of appropriate action (p = 0.03). The relationship between knowledge and action was not accounted for by other potential confounders.

CONCLUSIONS

Trauma patients retain minimal knowledge about infection risk after splenectomy and are not likely to pursue appropriate medical care. Time since injury negatively influences patient actions. Healthcare providers must be more proactive to develop new strategies in educating these patients, particularly those without comorbidities and those greater than 3 years postsplenectomy.

Subtotal splenectomy preserving the lower pole in rats: technical, morphological and functional aspects

PURPOSE: To assess the possibility of preserving the lower pole of the spleen, supplied by the inferior lobar vessels and segmental vessels, or by vessels of the gastrosplenic ligament, in subtotal splenectomy; to study the viability and function of the lower pole of the spleen. METHODS: Thirty-six male Wistar rats were used in this study. Said animals weighed 273-390 g ( 355.2 ± 30.5 g ), and were randomly distributed into three groups. Group 1 comprised ten animals which were submitted to exploratory laparotomy with spleen manipulation (sham operation). Group 2 comprised 16 animals which were submitted to total splenectomy. Group 3 comprised ten animals which were submitted to subtotal splenectomy, preserving the lower pole of the spleen. Blood was collected from all animals before and 90 days after surgery to measure the levels of cholesterol and triglycerides. The animals were sacrificed 90 days after surgery. Spleens and remaining spleens were removed for macroscopic and microscopic examination. RESULTS: Surgery was performed with no complications in all groups. Six animals died in group 2. Spleens of groups 1 and 2, and lower poles of group 3 were macroscopically viable. Apparent white pulp hyperplasia was observed in group 1. In group 3, slight inflammation and capsular fibrosis were observed at the incision site, as well as diffuse hemosiderosis in the red pulp. Average mass of remaining spleen was 35.84% ± 4.31%. No significant difference was observed between preoperative and late postoperative lipid levels in groups 1 and 3 (p > 0.05). Late postoperative lipid levels significantly increased in group 2. CONCLUSIONS: Preservation of the lower pole of the spleen (supplied by gastrosplenic vessels or inferior lobar vessels and segmental vessels) was possible with subtotal splenectomy. The lower pole was macroscopically and microscopically viable in all cases. Subtotal splenectomy preserving the lower pole prevented changes in lipid levels, which were observed in rats submitted to total splenectomy. Plasma lipid levels in rats submitted to subtotal splenectomy were similar to those observed in sham operated rats.

Surgical Infection Society Guidelines for Vaccination after Traumatic Injury

BACKGROUND

Recommendations for vaccination of injured patients against infection are evolving. Newly-recognized infections, safety considerations, changing epidemiology, and redefinition of patient groups at risk are factors that may influence vaccine development priorities and recommendations for immunization. However, recommendations must often be formulated based on incomplete data, forcing reliance on expert opinion to address some crucial questions. These guidelines provide evidence-based recommendations for the prevention or treatment of infectious morbidity and mortality after traumatic injury, such as soft tissue wounds, human or animal bites, or after splenectomy.

METHODS

A panel of experts conducted a thorough review of published literature, as well as information posted on the internet at the websites of the U.S. Centers for Disease Control and Prevention, among others. MEDLINE was searched for the period 1966-2004 using relevant terms including "anthrax," "rabies," "tetanus," "tetanus toxoid," and " splenectomy," in combination with "vaccine" and "immunization." The Cochrane database was searched also. Reference lists were cross-referenced for additional relevant citations. All published reports were analyzed for quality and graded, with the strength of the recommendation proportionate to the quality of the supporting evidence.

RESULTS

Recommendations are provided for pre- and post-exposure prophylaxis of rabies and anthrax. For tetanus prophylaxis, recommendations are provided for prophylaxis of acute wounds stratified y age and prior immunization status, and for immunization of persons at high risk. After splenectomy, it is recommended that all persons ages 2-64 years receive 23- valent pneumococcal vaccine and meningococcal vaccine, with Haemophilus influenzae type B vaccine administered to high-risk patients as well (all are Grade D recommendations). Vaccination should be given two weeks before elective splenectomy (Grade C), or two weeks after emergency splenectomy (Grade D). A booster dose of pneumococcal vaccine is recommended after five years (Grade D); no re- vaccination recommendation is made for meningococcal or Haemophilus influenzae type B vaccine. Recommendations for prophylaxis of splenectomized children under the age of five years are also provided.

CONCLUSION

There are limited data on the use of vaccines after injury. This document brings together a disparate literature of variable quality into a discussion of the infectious risks after injury relevant to vaccine administration, a summary of safety and adverse effects of vaccines, and evidence-based recommendations for vaccination.

The prevention and treatment of bacterial infections in children with asplenia or hyposplenia: practice considerations at the Hospital for Sick Children, Toronto

Children born without a spleen or who have impaired splenic function, due to disease or splenectomy, are at significantly increased risk of life-threatening bacterial sepsis. The mainstays of prevention are education, immunization, and prophylactic antibiotics. The availability of conjugate 7-valent pneumococcal vaccines for use in children to age 9 years at least, as well as conjugate meningococcal C vaccine in some countries, for use beginning in infancy, appear to represent beneficial additions, but not substitutions, to previous recommendations for the use of polysaccharide 23-valent pneumococcal and quadrivalent A, C, Y, W-135 vaccines. Routine immunization against H. influenzae type b should continue with non-immunized children older than age 5 years receiving two doses 2 months apart, similar to children who have not previously received conjugate pneumococcal vaccine in infancy. Annual influenza immunization, which reduces the risk of secondary bacterial infection, is also recommended for asplenic children and their household contacts. Many experts continue prophylaxis indefinitely although prophylaxis of the penicillin allergic child remains suboptimal.