Prevention and treatment of infection in patients with an absent or hypofunctional spleen: A British Society for Haematology guideline

Guidelines for the prevention and treatment of infection in patients with an absent or dysfunctional spleen were published by the British Committee for Standards in Haematology in 1996 and updated in 2002 and 2011. With advances in vaccinations and changes in patterns of infection, the guidelines required updating. Key aspects included in this guideline are the identification of patients at risk of infection, patient education and information and immunisation schedules. This guideline does not address the non-infective complications of splenectomy or functional hyposplenism (FH). This replaces previous guidelines and significantly revises the recommendations related to immunisation. Patients at risk include those who have undergone surgical removal of the spleen, including partial splenectomy and splenic embolisation, and those with medical conditions that predispose to FH. Immunisations should include those against Streptococcus pneumoniae (pneumococcus), Neisseria meningitidis (meningococcus) and influenza. Haemophilus influenzae type b (Hib) is part of the infant immunisation schedule and is no longer required for older hyposplenic patients. Treatment of suspected or proven infections should be based on local protocols and consider relevant anti-microbial resistance patterns. The education of patients and their medical practitioners is essential, particularly in relation to the risk of serious infection and its prevention. Further research is required to establish the effectiveness of vaccinations in hyposplenic patients; infective episodes should be regularly audited. There is no single group ideally placed to conduct audits into complications arising from hyposplenism, highlighting a need for a national registry, as has proved very successful in Australia or alternatively, the establishment of appropriate multidisciplinary networks.

Lessons from prospective longitudinal follow-up of a French APECED cohort

BACKGROUND

APECED syndrome is a rare disease caused by biallelic mutations of the AIRE gene, usually presenting with the triad "hypoparathyroidism-adrenal failure-chronic mucocutaneous candidiasis (CMC)" and non-endocrine manifestations. The aim of this study was to determine the molecular profile of the AIRE gene, the prevalence of rare manifestations and to characterize immunological disturbances in a French cohort.

PATIENTS AND METHODS

A national, multicenter prospective observational study to collect genetic, clinical, biological and immunological data (NCT03751683).

RESULTS

25 patients (23 families) were enrolled. Eleven distinct AIRE variants were identified, two of which were not previously reported: an intronic variant, c.653-70G > A, and a c.1066del (p.Arg356GlyfsX22) variant (exon 9). The most common was the Finnish variant c.769C > T (16 alleles), followed by the variant c.967_979del13 (15 alleles), which seemed associated with a less severe phenotype. 17/25 patients were homozygote. The median number of clinical manifestations was seven; 19/25 patients presented with the hypoparathyroidism-adrenal failure-CMC triad, 8/13 showed pulmonary involvement, 20/25 had ectodermal dystrophy, 8/25 had malabsorption, and 6/23 had asplenia. Fifteen out of 19 patients had NK cell lymphopenia with an increase in CD4+ and CD8+ T lymphocytes and an age-dependent alteration of B lymphocyte homeostasis compared with matched controls (p < 0.001), related to the severity of the disease. All tested sera (n = 18) were positive for anti-interferon-α, 15/18 for anti-interleukin-22 antibodies, and 13/18 for anti-interleukin-17F antibodies, without clear phenotypic correlation other than with CMC.

CONCLUSION

This first prospective cohort showed a high AIRE genotype variability, with two new gene variants. The prevalence of potentially life-threatening non-endocrine manifestations, was higher with systematic screening. These manifestations could, along with age-dependent B-cell lymphopenia, contribute to disease severity. Systematic screening for all the manifestations of the syndrome would allow earlier diagnosis, supporting vaccination, and targeted therapeutic approaches.

Early and long-term outcomes following cardiac surgery for patients with heterotaxy syndrome

Objective

Heterotaxy syndrome is a complex multisystem abnormality historically associated with high morbidity and mortality. We sought to evaluate the early and long-term outcomes after cardiac surgery in heterotaxy syndrome.

Methods

This is a single-center retrospective review of patients with heterotaxy syndrome undergoing single-ventricle palliation or primary or staged biventricular repair from 1998 to 2018. Patients were stratified by single ventricle versus biventricular physiology, and the severity of atrioventricular valve regurgitation. Demographics, anatomic characteristics, and early and late outcomes, including the length of stay, mortality, and surgical or catheter reinterventions, were analyzed.

Results

Among 250 patients, 150 (60%) underwent biventricular repair. In-hospital mortality was 7.6% (n = 19). Median follow-up was 5.2 (range, 0-16) years. Among survivors to discharge, mortality was 19% (n = 44) and reintervention was 52% (n = 120). Patients with moderate/severe atrioventricular valve regurgitation were older (32 vs 16 months, P = .02), were more likely to experience adverse events during their index surgical admission (72% vs 46%, P < .001), and had longer in-hospital length of stay (20 vs 12 days, P = .009). Among patients with moderate to severe atrioventricular valve regurgitation, single-ventricle palliation is associated with a greater risk of unplanned reintervention compared with patients undergoing biventricular repair (hazard ratio, 2.13; CI, 1.10-4.12; P = .025).

Conclusions

There was no significant difference in early or late outcomes in single-ventricle versus biventricular repair strategies in heterotaxy. In the subgroup of patients with moderate/severe atrioventricular valve regurgitation, patients who underwent single-ventricle palliation were 2.5 times more likely to need a late reintervention compared with those undergoing biventricular repair.

Heterotaxy Syndrome With Right Isomerism and Interrupted Inferior Vena Cava: A Case Report and Literature Review

Heterotaxy syndrome (HS) occurs in developing embryos due to an inability to establish the normal anatomy, which manifests as abnormal symmetry and malposition of the thoracoabdominal viscera and vasculature, including cardiac and extracardiac anomalies. It is classified as right or left atrial isomerism. This classification depends on the atrial appendage morphology and the extracardiac defect associated with it. Right isomerism usually presents with right atrial appendages (RAA), asplenia, total anomalous pulmonary venous return, and severe pulmonary stenosis. In contrast, left isomerism usually presents with left atrial appendages, polysplenia, and an interrupted inferior vena cava (IVC). The interrupted IVC feature has never been reported with the right isomerism. Diagnosis of HS may take place prenatally or a few days postnatally due to the severe cardiac defect, whereas a left isomerism diagnosis may be delayed until adulthood. Despite the popularity of the HS classification, we reported a rare presentation of an interrupted IVC, dextrocardia, a right-sided aortic arch, and a total anomalous pulmonary venous return, which occurred along with the right isomerism major components (asplenia syndrome).

Streptococcus pneumoniae Infection in Patients with Asplenia: A Spanish Perspective over a 25-Year Period

Anatomical or functional asplenia constitutes a risk factor for Streptococcus pneumoniae (SP) infection, being more frequent in children and the elderly and in people with multiple comorbidities. We aimed to describe the impact of invasive pneumococcal disease (IPD) on the clinical features and outcomes of patients hospitalized for asplenia in Spain. Discharge reports from the Spanish Minimum Basic Data Set were used to retrospectively analyze hospital discharge data with a diagnosis of asplenia from 1997 to 2021. A total of 132,257 patients with asplenia (splenectomized/non-splenectomized) were identified from the Spanish database. Among the cases, 177 (37.5%) patients with splenectomy and 295 (62.5%) patients without splenectomy developed IPD. The clinical presentations (non-infection vs. infection) did not significantly differ between the two reference groups, except for patients with COPD, rheumatoid disease, AIDS, other neurological disorders, metastatic cancer, and drug abuse. The risk factors for IPD were also more frequently reported in patients without splenectomy (p < 0.001) and with comorbidities (p = 0.005). The study of patients with asplenia provides relevant information about the state of SP infection. This epidemiological tracking can serve to better understand the comorbidities that affect them, the risk factors for the disease, the prediction of antibiotic use, and vaccination in public health, among other factors.

Pneumococcal Septic Shock Syndrome: A Deadly Condition Despite Vaccination

Invasive pneumococcal disease is a serious infection with an elevated case-fatality rate that can be even higher among patients with asplenia. Its impact has been blunted by the widespread use of vaccines; even recently, in 2021, two new pneumococcal conjugate vaccines emerged. The authors present a case of a 58-year-old male, splenectomised with the immunisation schedule complete, who died of invasive pneumococcal disease with a fulminant course. It is highlighted that fever in a patient with impaired splenic function is an emergency, and despite the success of immunisation in reducing pneumococcal carriage and invasive disease, serotypes continue to change. Also, the local epidemiology may help guide situations where the immunisation recommendations are dubious regarding the implementation of the new vaccines.

Intra-erythrocytic vacuoles in asplenic patients: elusive genesis and original clearance of unique organelles

The spleen plays a dual role of immune response and the filtration of red blood cells (RBC), the latter function being performed within the unique microcirculatory architecture of the red pulp. The red pulp filters and eliminates senescent and pathological RBC and can expell intra-erythrocytic rigid bodies through the so-called pitting mechanism. The loss of splenic function increases the risk of infections, thromboembolism, and hematological malignancies. However, current diagnostic tests such as quantification of Howell-Jolly Bodies and splenic scintigraphy lack sensitivity or are logistically demanding. Although not widely available in medical practice, the quantification of RBC containing vacuoles, i.e., pocked RBC, is a highly sensitive and specific marker for hyposplenism. The peripheral blood of hypo/asplenic individuals contains up to 80% RBC with vacuoles, whereas these pocked RBC account for less than 4% of RBC in healthy subjects. Despite their value as a spleen function test, intraerythrocytic vacuoles have received relatively limited attention so far, and little is known about their origin, content, and clearance. We provide an overview of the current knowledge regarding possible origins and mechanisms of elimination, as well as the potential function of these unique and original organelles observed in otherwise "empty" mature RBC. We highlight the need for further research on pocked RBC, particularly regarding their potential function and specific markers for easy counting and sorting, which are prerequisites for functional studies and wider application in medical practice.

HSV Encephalomyelitis in an Immunocompetent Patient With Prior Splenectomy

A 44-year-old male with history of asplenia, provoked PE, and hyperlipidemia presented with ascending paralysis, bowel and bladder incontinence and altered mental status, and progressively developed acute hypoxic respiratory failure. Initial workup including CT head, magnetic resonance imaging (MRI) brain, and lumbar puncture which was concerning for herpes simplex virus (HSV) meningoencephalitis; out of caution he was started on multiple antibiotics consequently resulting in the development of Clostridium difficile (C.diff). He also received two doses of IVIG. He was transferred to our institution and after interval re-imaging via MRI brain and spinal surveys and repeat lumbar punctures, he was found to have a high CSF HSV titer and positive GAD 65 antibody, the latter likely a false positive due to IVIG administration. IVIG was not continued from the outside hospital due to the development of deep vein thrombosis (DVT), and the risks of plasmapheresis outweighed the benefits. The patient gradually improved after a prolonged course of acyclovir and was downgraded out of the Neuroscience ICU (NSICU), however decompensated due to rectal bleeding, and subsequently went into cardiac arrest. Though this patient underwent a splenectomy, his relative immunocompetency towards non-encapsulated organisms should have been preserved. It has not been clearly described in the literature how and why HSV encephalomyelitis takes a fulminant course in immunocompetent patients, including our asplenic patient. Furthermore, definitive treatment and management of this condition remains unclear. Severity of HSV encephalomyelitis has not been clearly described in the literature, particularly in immunocompetent patients (such as this asplenic patient).

Babesiosis: An Atypical Cause of Respiratory Failure

Babesiosis is a parasitic infection of the Babesia protozoa, which has been increasing in incidence in endemic areas of the United States. Symptoms of babesiosis can occur on a wide spectrum, from a mild flu-like illness to a fulminant disease course. Known complications of severe cases include intravascular hemolytic anemia and may involve the coagulation system, heart, spleen, kidneys, and in some cases, the lungs. This case report describes an 81-year-old, asplenic female in northern Wisconsin who presented to a hospital with shortness of breath and a non-productive cough. Definitive diagnosis of babesiosis, which was made through both a nucleic acid panel and blood smear, was initially delayed given the rare pulmonary manifestation of babesiosis. When the lungs are involved in the disease course, non-cardiogenic pulmonary edema leading to acute respiratory distress syndrome is among the most commonly seen complications. The pathophysiology of pulmonary involvement has not been made entirely clear but is most likely multifactorial, including the sequelae of changes to both the patient's red blood cells and pulmonary vasculature. This report highlights that atypical tick-borne illnesses like babesiosis should be considered as a cause of acute respiratory failure, particularly in the setting of sepsis and fever. The threshold for parasitic testing should be low in patients in endemic regions with risk factors, including increased age and history of asplenia, as babesiosis frequently has no localizing symptoms to suggest a protozoan infection. As babesiosis incidence continues to rise, prompt diagnosis and proper treatment can prevent severe complications and death in patients.

Disseminated Cryptococcosis in an HIV-Negative Patient With Liver Cirrhosis and Asplenia: A Rare but Dreadful Disease

Cryptococcosis (cryptococcal infection) is a severe life-threatening fungal infection. It is seen worldwide, specifically in immunocompromised, mainly in human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS)-infected individuals. Cryptococcal infection can present with meningitis, pneumonia, peritonitis, disseminated cryptococcosis, and cryptococcal fungemia. Here, we report the case of an HIV-negative Caucasian male in his early 50s with liver cirrhosis and asplenia who presented to our hospital with bilateral foot cellulitis and pneumonia. He was eventually diagnosed with disseminated cryptococcosis. Even with appropriate treatment, he developed multiorgan failure and finally expired. The disseminated cryptococcal infection has a very high mortality rate in patients with liver cirrhosis and asplenia. Liver cirrhosis is an independent risk factor, and asplenia is a comorbid condition for cryptococcal infection in HIV-negative patients. Healthcare providers should have a high suspicion of cryptococcosis in these patients. Early testing with cryptococcal antigen assay and initiation of an appropriate antimicrobial regimen can help minimize bad outcomes.

Burden of COVID-19 disease and vaccine coverages in Apulian splenectomized patients: A retrospective observational study

Splenectomy/asplenia is a condition associated with immune-compromission and specific vaccines are recommended for these patients, including the anti-COVID-19 vaccine. Among the high-risk group for which vaccination was prioritized in Italy, the immunocompromised patients after therapies or treatments were included. The Apulian regional archive of hospital discharge forms was used to define the list of splenectomized Apulian inhabitants, considering data from 2015 through 2020. The overall vaccination status of asplenic patients was assessed via data collected from the Regional Immunization Database. The history of SARS-CoV-2 infection and the infectious disease outcomes were extracted from the Italian Institute of Health platform "Integrated surveillance of COVID-19 cases in Italy". 1219 Apulian splenectomized inhabitants were included; the incidence rate of SARS-CoV-2 infection was 15.0 per 100 persons-year with a proportion of re-infection equal to 6.4%; the proportion of hospitalization was 2.9%, with a case-fatality rate of 2.6%. The vaccine coverage (VC) for the anti-COVID-19 vaccine basal routine was 64.2%, for the first booster dose was 15.4%, and for the second booster dose was 0.6%. A multifactorial approach is needed to increase the vaccination uptake in this sub-group population and to increase the awareness of the asplenia-related risks to patients and health personnel.

Diagnosis of Dextrocardia with a Pictorial Rendition of Terminology and Diagnosis

A significant number of patients with dextrocardia and other cardiac malpositions have other congenital heart defects (CHDs). The incidence of CHDs in subjects with cardiac malpositions is significantly greater than that in normal children, and the prevalence varies with the associated visceroatrial situs. The most useful approach to diagnosis is segmental analysis. Firstly, dextroposition should be excluded. In segmental analysis, the visceroatrial situs, ventricular location, status of atrioventricular connections, the great artery relationship, and conotruncal relationship are determined with the use of electrocardiogram (ECG), chest X-ray, and echocardiographic studies, and, when necessary, other imaging studies, including angiography. Following identification of the afore-mentioned segments, the associated defects in the atrial and ventricular septae, valvar and vascular stenosis or atresia may be determined by a review of the historical information, physical examination, and analysis of chest roentgenogram, ECG, and echocardiographic studies. Along the way, a pictorial rendition of the terminology and diagnosis of cardiac malpositions is undertaken.

Fontan Palliation in Patients with Heterotaxy Syndrome: A Five Decade Experience

BACKGROUND

Patients with heterotaxy syndromes (right and left atrial isomerism) are at high risk of poor outcomes after single-ventricle palliation. However, the long-term outcomes and specific parameters associated with poor outcomes are incompletely understood.

METHODS

A retrospective review was performed of all patients with atrial isomerism who had a Fontan at our institution from 1973 to 2020. Standard demographic, as well as pre-, peri-, and postoperative parameters were collected. Features and outcomes of patients with polysplenia were compared to asplenia. Outcomes were analyzed for effect during 4 eras: (1: 1973-1984; n = 27), (2: 1985-1994; n = 93), (3: 1995-2004; n = 28), and (4: 2005-2020; n = 10).

RESULTS

Of the 1176 patients who had a Fontan operation, 158 (14%) had a heterotaxy syndrome. The median age at the time of Fontan was 8 (9) years. Early mortality was 20% and was greater in patients with asplenia compared to polysplenia (27% vs. 12%, p = .019). But it substantially improved over time (61% in era 1 vs. 7%-10% in the more recent eras (p < .001)), as did transplant-free survival (22% at 10 years in era 1 vs. 88% in era 4, p < .001). Transplant-free survival was significantly lower in patients with asplenia versus those with polysplenia (p = .014), and patients with heterotaxy had lower survival than nonheterotaxy (p = .01). This was largely due to the asplenia group (p < .001) (hazard ratio = 3.05, p = .007).

CONCLUSIONS

After Fontan operation, patients with heterotaxy, particularly asplenia, continue to demonstrate worse transplant-free survival than nonheterotaxy patients. Early mortality and long-term transplant-free survival have improved in more recent eras.

Surgical management of hearts with isomeric atrial appendages

BACKGROUND AND AIM

On the basis of previously published accounts, coupled with our own experience, we have assessed the surgical approaches to patients with isomeric atrial appendages.

METHODS

We reviewed pertinent published studies on surgical treatment of individuals with isomeric atrial appendages, with the pertinent surgical details provided by most of the manuscripts.

RESULTS

Half of patients with right isomerism, and two-thirds of those with left isomerism have bilateral superior caval veins. Azygos extension of the inferior caval vein is reported in three-quarters of those with left isomerism. The coronary sinus is universally absent in right isomerism, along with totally anomalous pulmonary venous connection, and is absent in two-fifths of those with left isomerism. Univentricular atrioventricular connections are expected in up to three-quarters of those with right isomerism. Atrioventricular septal defect is reported in up to four-fifths, more frequently in right isomerism, with such patients typically having discordant ventriculoatrial connections or double outlet right ventricle. Reported mortalities extend to 85% for those with right, and 50% for those with left isomerism. In right isomerism, mortality is up to 54% for systemic-to-pulmonary arterial shunting, up to 75% for univentricular repair, and up to 95% for repair of totally anomalous pulmonary venous connection itself. No more than one-quarter had undergone Fontan completion, with reported mortalities of 21%.

CONCLUSION

Early surgical results are satisfactory in patients with left isomerism, but disappointing for those with right. Recent advances in cardiac and liver transplantation may offer improved survival.

Spleen angiosarcoma: a world review

Introduction: Spleen angiosarcoma (SA) is a rare malignant neoplasm that arises from the splenic vascular endothelium, with only around 300 cases reported to date. Due to a limited number of reported cases, there is a paucity of data and a lack of understanding of its presentation, diagnosis, and management. In this study, we aim to provide a comprehensive review of SA.Areas covered: On 27 February 2021, a literature search was done in PubMed and Embase database. The search yielded 122 articles involving 205 patients. The focus was on patient demographics, risk factors, clinical presentations, investigation results, preliminary diagnoses, therapies provided, and patient outcomes. These factors were analyzed to identify possible risk factors, diagnostic modalities, and therapeutic principles that were not mentioned before.Expert opinion: The clinical presentation or investigation results of patients with SA are often nonspecific. Hence, they may not be sufficient to clinch the diagnosis of SA if used alone. The authors recommend a triple assessment of clinical examination, imaging findings, and pathology to diagnose SA with high accuracy. Splenectomy should be the mainstay of management, with chemotherapy and radiotherapy considered as adjuncts, especially in the presence of metastases.

Heterotaxy syndrome with complex congenital heart disease, facial palsy, and asplenia: A rare newborn finding

Heterotaxy syndrome is associated with asplenia/polysplenia and complex congenital heart disease. Facial palsy in heterotaxy is very rare. The management is still challenging with a poor prognosis. Proper counseling to the family about the disease course, treatment modalities, and outcomes is essential.

Improved heart transplant survival for children with congenital heart disease and heterotaxy syndrome in the current era: An analysis from the pediatric heart transplant society

BACKGROUND

Challenges exist with heterotaxy due to the complexity of heart disease, abnormal venous connections, and infection risks. This study aims to understand heart transplant outcomes for children with heterotaxy.

METHODS

All children with congenital heart disease listed for transplant from 1993 to 2018 were included. Those with and without heterotaxy were compared. Waitlist outcomes and survival post-listing and transplant were analyzed. Post-transplant risk factors were identified using multiphase parametric hazard modeling.

RESULTS

There were 4814 children listed, of whom 196 (4%) had heterotaxy. Heterotaxy candidates were older (5.8 ± 5.7 vs 4.2 ± 5.5 years, p < 0.01), listed at a lower urgency status (29.8% vs 18.4%, p < 0.01), more commonly single ventricle physiology (71.3% vs 59.2%, p < 0.01), and less often supported by mechanical ventilation (22% vs 29.1%, p < 0.05) or extracorporeal membrane oxygenation (3.6% vs 7.5%, p < 0.05). There were no differences in waitlist outcomes of transplant, death, or removal. Overall, post-transplant survival was worse for children with heterotaxy: one-year survival 77.2% vs 85.1%, with and without heterotaxy, respectively. Heterotaxy was an independent predictor for early mortality in the earliest era (1993-2004), HR 2.09, CI 1.16-3.75, p = 0.014. When stratified by era, survival improved with time. Heterotaxy patients had a lower freedom from infection and from severe rejection, but no difference in vasculopathy or malignancy.

CONCLUSIONS

Mortality risk associated with heterotaxy is mitigated in the recent transplant era. Early referral may improve waitlist outcomes for heterotaxy patients who otherwise have a lower status at listing. Lower freedom from both infection and severe rejection after transplant in heterotaxy highlights the challenges of balancing immune suppression.

Prevalence and distribution of functional splenic tissue after splenectomy

BACKGROUND

Individuals splenectomised for trauma have lower infection rates than those splenectomised for other conditions. Residual functional splenic tissue (FST) after splenectomy may provide ongoing immunological protection.

AIMS

To quantify the prevalence and volume of residual FST post-splenectomy using standard testing.

METHODS

Splenectomised adults were recruited from the Spleen Australia clinical registry. Eligible individuals had been splenectomised at least 1 year prior to their visit and resided in Victoria. Splenic function was identified by evaluating Howell-Jolly bodies and IgM memory B cells. A 99m-Technetium-labelled, heat-denatured erythrocyte scintigraphic scan was performed if splenic function was detected.

RESULTS

Initially, 75 splenectomised individuals (all cause) were recruited, with a median of 58 years of age and who were splenectomised a median of 14 years previously. The most common indications for splenectomy were trauma (30.7%) and haematological disease (28.0%). Scintigraphy identified FST in nine individuals (12.0%). Eight had been splenectomised for trauma. In this cohort, 34.8% of individuals splenectomised for trauma had residual FST. To explore our findings further, 45 additional individuals were recruited, predominately individuals splenectomised for trauma. Twenty-five individuals completed assessments by December 2018. An additional 11 individuals had FST, of whom 9 had been splenectomised for trauma. Overall, we identified 20 individuals with residual FST. Volumes ranged from 2.2 to 216.0 cc. We saw individuals with accessory spleens and splenotic nodules and an individual with both. Seventeen individuals had been splenectomised for trauma.

CONCLUSIONS

Residual FST is commonly seen in individuals splenectomised for trauma. It can present in varying distributions and of varying volume. The clinical significance is unclear.

Roseomonas gilardii Bacteremia in a Patient With HbSβ0-thalassemia: Clinical Implications and Literature Review

Roseomonas gilardii is a Gram-negative coccobacillus identified in immunocompromised pediatric patients. A 5-year-old male with a history of HbSβ thalassemia status postsurgical splenectomy presented to the emergency department with fever. Blood cultures grew R. gilardii at 63 hours, but the patient had been discharged home at 48 hours. The patient was readmitted for repeat cultures and initiated on meropenem for 10 days as Roseomonas spp. are often resistant to third generation cephalosporins. R. gilardii is a rare cause of bacteremia in immunocompromised patients. Clinicians should consider Roseomonas in slow growing Gram-negative rod bacteremias, and consider meropenem as empiric coverage.

Management strategies for human babesiosis

INTRODUCTION

Human babesiosis is reported throughout the world and is endemic in the northeastern and northern Midwestern United States and northeastern China. Transmission is primarily through hard bodied ticks. Most cases of severe disease occur in immunocompromised individuals and may result in prolonged relapsing disease or death.

AREAS COVERED

We provide a summary of evidence supporting current treatment recommendations for immunocompetent and immunocompromised individuals experiencing babesiosis.

EXPERT OPINION

Most cases of human babesiosis are successfully treated with atovaquone and azithromycin or clindamycin and quinine. Severe disease may require prolonged treatment.

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

Background

This study evaluated the impact of a dedicated outpatient service on vaccination uptake after splenectomy and on the incidence of postsplenectomy sepsis.

Methods

From 2009 to 2016 at the University Hospital Freiburg (Germany), asplenic patients were referred to a dedicated outpatient service, provided with comprehensive preventive care including vaccinations, and enrolled in a prospective cohort study. The impact of the service on vaccination uptake and the occurrence of severe sepsis/septic shock was compared between patients who had splenectomy (or were asplenic) within 3 months of study entry (“early study entry”) and those who had splenectomy (or were asplenic) >3 months before study entry (“delayed study entry”).

Results

A total of 459 asplenic patients were enrolled, and 426 patients were followed prospectively over a median period of 2.9 years. Pneumococcal vaccine uptake within 3 months of splenectomy or first diagnosis of asplenia was 27% vs 71% among delayed study entry and early study entry patients, respectively (P < .001). Forty-four episodes of severe sepsis or septic shock occurred in study patients: 22 after study entry and 22 before study entry. Streptococcus pneumoniae was more frequent among sepsis episodes that occurred before study entry (8/22) than after study entry (1/22 episodes). For episodes occurring after study entry, only a higher Charlson comorbidity index score was significantly associated with severe sepsis/septic shock postsplenectomy.

Conclusions

With dedicated outpatient care, high uptake of pneumococcal vaccination postsplenectomy was achieved. Sepsis episodes were largely of nonpneumococcal etiology in patients who had received dedicated postsplenectomy care.

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.

Beware of the dog! Septic shock due to Capnocytophaga canimorsus revealed on peripheral blood smear

A blood smear examination led to the diagnosis of severe bacterial infection in a splenectomized patient. The knowledge of a relevant clinical information (recent dog bite) could have led to immediate presumptive identification of the causative agent, Capnocytophaga canimorsus.

Outcomes in adults with congenital heart disease and heterotaxy syndrome: A single-center experience

BACKGROUND

Heterotaxy syndrome (HS) is a condition in which the thoracoabdominal organs demonstrate an abnormal lateral arrangement and is often associated with congenital heart disease (CHD). Little is known about the adult HS population with CHD.

OBJECTIVE

To describe the outcomes and sociodemographics of the adult CHD population with HS.

METHODS

Records of patients 18 years of age or older with diagnoses of both CHD and HS at Texas Children's Hospital from 1964 to 2018 were reviewed.

RESULTS

Sixty-two patients met inclusion criteria. Median age was 22.7 [IQR 19.6-30.0] years; 26 (42%) were female; and 13 (21%) of patients had a gap in care of >3 years. Median follow-up time in adulthood was 2.9 [IQR 1.3-8.2] years. Forty-three (69%) of patients had single ventricle heart disease, 31 (71%) of whom completed Fontan circulation. A total of 36 interventions occurred in 24 patients which included 16 cardiac catherization interventions, 13 electrophysiology-related procedures, and 18 surgical procedures including 2 orthotopic heart transplants. The median age for death or heart transplant was 45.3 (95%CI 34.3-56.1) years. Heart failure-free survival was 80.8 ± 5.2%, 58.7 ± 11.0%, and 31.1 ± 15.7% at 20, 30, and 40 years old, respectively. Cerebrovascular accident-free survival was 84.3 ± 5.1%, 54.2 ± 11.3%, and 40.6 ± 14.5% at 20, 30, and 40 years old, respectively. Tachyarrhythmia-free survival was 54.0 ± 7.1%, 29.2 ± 8.3%, and 19.5 ± 9.7% at 20, 30, and 40 years old and bradyarrhythmia-free survival was 66.0 ± 6.3%, 41.7 ± 9.4%, and 33.4 ± 10.6% at ages 20, 30, and 40 years, respectively.

CONCLUSIONS

At a tertiary referral center, adult patients with CHD and HS have high rates of comorbidities and early death or heart transplant. Longitudinal surveillance and further exploration into factors associated with improved survival in this population are warranted.

Mutations in RPSA and NKX2-3 link development of the spleen and intestinal vasculature

Idiopathic intestinal varicosis is a developmental disorder defined by dilated and convoluted submucosal veins in the colon or small bowel. A limited number of families with idiopathic intestinal varices has been reported, but the genetic cause has not yet been identified. We performed whole‐exome and targeted Sanger sequencing of candidate genes in five intestinal varicosis families. In four families, mutations in the RPSA gene were found, a gene previously linked to congenital asplenia. Individuals in these pedigrees had intestinal varicose veins and angiodysplasia, often in combination with asplenia. In a further four‐generation pedigree that only showed intestinal varicosities, the RPSA gene was normal. Instead, a nonsense mutation in the homeobox gene NKX2‐3 was detected which cosegregated with the disease in this large family with a LOD (logarithm of the odds) score of 3.3. NKX2‐3 is a component of a molecular pathway underlying spleen and gut vasculature development in mice. Our results provide a molecular basis for familial idiopathic intestinal varices. We provide evidence for a relationship between the molecular pathways underlying the development of the spleen and intestinal mucosal vasculature that is conserved between humans and mice. We propose that clinical management of intestinal varices, should include assessment of a functional spleen.

Blood reservoir function in patients with Fontan circulation and asplenia syndrome

Splanchnic circulation constitutes a major portion of the vasculature capacitance and plays an important role in maintaining blood perfusion. Because patients with asplenia syndrome lack this vascular bed as a blood reservoir, they may have a unique blood volume and distribution, which may be related to their vulnerability to the haemodynamic changes often observed in clinical practice. During cardiac catheterisation, the mean circulatory filling pressure was calculated with the Valsalva manoeuvre in 19 patients with Fontan circulation, including 5 patients with asplenia syndrome. We also measured the cardiac output index and circulatory blood volume by using a dye dilution technique. The blood volume and the mean circulatory filling pressure and the venous capacitance in patients with asplenia syndrome were similar to those in the remaining patients with Fontan circulation (85 ± 14 versus 77 ± 18 ml/kg, p = 0.43, 31 ± 8 versus 27 ± 5 mmHg, p = 0.19, 2.8 ± 0.6 versus 2.9 ± 0.9 ml/kg/mmHg, p = 0.86). Unexpectedly, our data indicated that patients with asplenia syndrome, who lack splanchnic capacitance circulation, have blood volume and venous capacitance comparable to those in patients with splanchnic circulation. These data suggest that (1) there is a blood reservoir other than the spleen even in patients with asplenia; (2) considering the large blood pool of the spleen, the presence of a symmetrical liver may represent the possible organ functioning as a blood reservoir in asplenia syndrome; and (3) if this is indeed the case, there may be a higher risk of hepatic congestion in patients with Fontan circulation with asplenia syndrome than in those without.

Novel Targeting to XCR1+ Dendritic Cells Using Allogeneic T Cells for Polytopical Antibody Responses in the Lymph Nodes

Vaccination strategy that induce efficient antibody responses polytopically in most lymph nodes (LNs) against infections has not been established yet. Because donor-specific blood transfusion induces anti-donor class I MHC antibody production in splenectomized rats, we examined the mechanism and significance of this response. Among the donor blood components, T cells were the most efficient immunogens, inducing recipient T cell and B cell proliferative responses not only in the spleen, but also in the peripheral and gut LNs. Donor T cells soon migrated to the splenic T cell area and the LNs, with a temporary significant increase in recipient NK cells. XCR1⁺ resident dendritic cells (DCs), but not XCR1⁻ DCs, selectively phagocytosed donor class I MHC⁺ fragments after 1 day. After 1.5 days, both DC subsets formed clusters with recipient CD4⁺ T cells, which proliferated within these clusters. Inhibition of donor T cell migration or depletion of NK cells by pretreatment with pertussis toxin or anti-asialoGM₁ antibody, respectively, significantly suppressed DC phagocytosis and subsequent immune responses. Three allogeneic strains with different NK activities had the same response but with different intensity. Donor T cell proliferation was not required, indicating that the graft vs. host reaction is dispensable. Intravenous transfer of antigen-labeled and mitotic inhibitor-treated allogeneic, but not syngeneic, T cells induced a polytopical antibody response to labeled antigens in the LNs of splenectomized rats. These results demonstrate a novel mechanism of alloresponses polytopically in the secondary lymphoid organs (SLOs) induced by allogeneic T cells. Donor T cells behave as self-migratory antigen ferries to be delivered to resident XCR1⁺ DCs with negligible commitment of migratory DCs. Allogeneic T cells may be clinically applicable as vaccine vectors for polytopical prophylactic antibody production even in asplenic or hyposplenic individuals.

Vancomycin-resistant Enterococcus faecium Empyema in an Asplenic Patient

Enterococcal empyema is a rare complication of pneumonia. We report the case of a 67-year-old asplenic man with pneumonia complicated by respiratory failure and empyema requiring decortication and prolonged chest tube drainage. Cultures of the empyema were initially negative, but later grew vancomycin-resistant Enterococcus faecium (VRE), which was successfully treated with linezolid. To our knowledge, this is only the second reported case of an empyema caused by VRE that was not associated with an intra-abdominal infection. We suspect superinfection due to airway or chest tube contamination as the most likely mechanism of infection. Physicians should consider multi-drug resistant organisms such as VRE in patients with empyema that fail to resolve with chest tube drainage and broad-spectrum antibiotics.

Impact of a spleen registry on optimal post-splenectomy vaccination and care

Objective: To evaluate quality of patient knowledge and rates of adherence to guidelines amongst splenectomised patients registered to the Spleen Australia registry. Method: Registrants recruited for assessment of residual splenic function post-splenectomy also underwent an assessment of quality of knowledge and a review of their long-term management. Eligible patients were ≥ 18 years of age, registered to the Spleen Australia clinical registry and had been splenectomised at least 1 year prior to their visit. Quality of knowledge was assessed using a validated questionnaire used in similar studies. Receipt of immunisations was validated by record review. Chemoprophylaxis use was self-reported by patients. Adherence was evaluated using Australian guidelines. Results: 77 patients were evaluated for education and adherence. 58% were female, mean age was 58 years, and median duration since splenectomy was 14 years. Most common indications for splenectomy were trauma and haematological conditions. 77% had good knowledge of key educational points to reduce chances of infection. Adherence to immunisations varied with poor adherence to vaccines introduced after 2010. Only 6 patients were adherent to all recommended immunisations. Increasing duration since registration was associated with poorer 13vPCV (p = 0.008) and 4vMenCV adherence (p = 0.001). Over 70% either currently or had previously used daily chemoprophylaxis and 66% had a supply of emergency antibiotics. Conclusions: Although registrants are receiving initial and booster vaccinations, they do not receive newly recommended vaccines. In order to maintain long-term adherence, we recommend streamlining health information systems, improving awareness strategies and improving financial access to vaccinations in the community with additional awareness of the activities of the registry.

Understanding of the significance and health implications of asplenia in a cohort of patients with haemaglobinopathy: possible benefits of a spleen registry

OBJECTIVES

Asplenia and hyposplenism carry a significant risk of ongoing morbidity and mortality which can be reduced by education, vaccination and antibiotic use. We aimed to assess education and other methods of prevention in a cohort of patients with haemoglobinopathy in a tertiary referral centre, which also had access to a post-splenectomy registry created to reduce post-splenectomy infection risk.

METHODS

A standardized questionnaire was used on patients who attended the service for regular therapy. Patients were also asked about standard post-splenectomy preventive therapies including antibiotics and vaccinations.

RESULTS

There were 49 patients who had either had a splenectomy or knew their spleen to be non-functional. Of these, nearly half knew themselves to be on the Victorian Spleen Registry (51.0%). The median knowledge score was 12 (range 4-17) out of a possible 18. Most significantly the benefits of the registry were not seen in terms of knowledge but in delivery of recommended vaccines and the use of a medical alert card.

CONCLUSION

This study examined knowledge and attitudes about splenectomy in a cohort of haemoglobinopathy patients in an Australian tertiary referral centre. The majority had good or fair knowledge with a strong association of some elements of post-splenectomy care with being placed on a spleen registry and having received targeted education. Implementation of systematic approaches by medical staff is likely to be the main benefit of a clinical registry approach in this setting.

HLX is a candidate gene for a pattern of anomalies associated with congenital diaphragmatic hernia, short bowel, and asplenia

Isolated congenital diaphragmatic hernia is often a sporadic event with a low recurrence risk. However, underlying genetic etiologies, such as chromosome anomalies or single gene disorders, are identified in a small number of individuals. We describe two fetuses with a unique pattern of multiple congenital anomalies, including diaphragmatic hernia, short bowel and asplenia, born to first-cousin parents. Whole exome sequencing showed that both were homozygous for a missense variant, c.950A>C, predicting p.Asp317Ala, in the H.20-Like Homeobox 1 (HLX1) gene. HLX is a homeobox transcription factor gene which is relatively conserved across species. Hlx homozygous null mice have a short bowel and reduced muscle cells in the diaphragm, closely resembling the anomalies in the two fetuses and we therefore suggest that the HLX mutation in this family could explain the fetal findings.

Factors influencing bacteraemia in patients with isomerism and CHD: the effects of functional splenic status and antibiotic prophylaxis

BACKGROUND

"Heterotaxy syndrome", best segregated as isomerism, is characterised by laterality defects of the thoraco-abdominal organs, causing functional impairment. In particular, the spleen is frequently affected, increasing susceptibility to bacteraemia. This study explored factors that may increase the risk of bacteraemia in patients with isomerism.

METHODS

We identified patients with CHD and isomerism. Review of outpatient, inpatient, and surgical records was conducted to collect data and determine trends in the cohort. A Cox regression analysis was conducted to determine factors influencing freedom from bacteraemia (Fig 1).

RESULTS

We identified 83 patients with CHD and isomerism - 17 (20%) who had documented episodes of bacteraemia with a total of 21 episodes. A majority (86%) were nosocomial. The median age at the time of bacteraemia was 4 months. Although splenic anatomy did appear to influence the risk of bacteraemia in univariate analysis, this significance was lost with multivariate analysis. None of the other factors was significantly associated in either univariate or multivariate analysis.

CONCLUSION

Specific factors such as splenic anatomy, atrial appendage isomerism, and antibiotic prophylaxis status are not significantly associated with the risk of bacteraemia in patients with CHD and isomerism. Nosocomial infections represent a majority of bacteraemia in these patients.

Overwhelming Postsplenectomy Infection: A Prospective Multicenter Cohort Study

BACKGROUND

Recent population-based cohort studies have questioned the role of pneumococci as the most frequent pathogen causing severe infection in patients after splenectomy. The aim of the study was to define the causative pathogens and clinical presentation of patients with overwhelming postsplenectomy infection (OPSI).

METHODS

In a prospective cohort study in 173 German intensive care units, we searched for patients with and without asplenia and community-acquired severe sepsis/septic shock. Clinical and laboratory variables and survival of patients were assessed.

RESULTS

Fifty-two patients with severe sepsis or septic shock with asplenia and 52 without asplenia were included. OPSI patients more often had a history of malignancy (38% vs 17%; P = .016) and had a lower body mass index (24 kg/m(2) vs 28 kg/m(2); P = .004). Streptococcus pneumoniae was detected more frequently in OPSI patients (42% vs 12% without asplenia; P < .001) and more frequently manifested as bloodstream infection (31% vs 6%; P = .002). Gram-negative infection was similar in both groups (12% vs 19%; P = .157). Pneumococcal vaccine coverage of OPSI patients was low overall (42% vs 8% among patients without asplenia; P < .001). Purpura fulminans was a frequent complication, developing in 19% of OPSI patients vs 5% of patients without asplenia (P = .038). The interval between splenectomy and OPSI was 6 years (range, 1 month-50 years). On multivariable Poisson regression, asplenia was the only predictive variable independently associated with pneumococcal sepsis (adjusted relative risk, 2.53 [95% confidence interval, 1.06-6.08]).

CONCLUSIONS

Pneumococcal infections remain the most important cause of severe sepsis and septic shock following splenectomy.

A Virtual Clinic Improves Pneumococcal Vaccination for Asplenic Veterans at High Risk for Pneumococcal Disease

We developed a "virtual clinic" to improve pneumococcal vaccination among asplenic adults. Using an electronic medical record, we identified patients, assessed their vaccination status, entered orders, and notified patients and providers. Within 180 days, 38 of 76 patients (50%) received a pneumococcal vaccination. A virtual clinic may optimize vaccinations among high-risk patients.

Asplenia in children with congenital heart disease as a cause of poor outcome

The absence of a spleen is a well-known risk factor for severe bacterial infections, especially due to encapsulated bacteria. Congenital asplenia can be part of multiple congenital abnormalities as in heterotaxy including Ivemark syndrome with congenital anomalies of the heart or great vessels, or it can be isolated, which is extremely rare. In these cases, asplenia is an important factor effecting mortality. In this report, the clinical courses of five children with asplenia and concomitant minor or complex cardiac anomalies are presented. The ages of the children ranged between 1.5 and 17 months at the time of diagnosis. All of the cases had had a history of hospitalisation for infectious diseases before the diagnosis. The patient who was diagnosed at 17 months old had a history pneumonia, urinary tract infection, and bacterial meningitis beginning at five months old. Three children had complex cardiac anomalies, one child had ventricular septal defect, and one child had atrial septal defect. Howell-Jolly bodies were determined in peripheral blood smear in all of the patients. The diagnoses of asplenia were confirmed with spleen scintigraphy. One of the patients with complex cardiac anomalies died a short time after diagnosis, because of cardiac failure. The rest of the four patients were vaccinated for encapsulated bacteria and were taken under antibiotic prophylaxis. These children did not need hospitalisation for infectious diseases during the follow-up period (5-40 months). In asplenic children, early diagnosis, antibiotic prophylaxis, and immunisation for encapsulated bacteria can decrease the risk of morbidity and mortality.

A review of guidance on immunization in persons with defective or deficient splenic function

The spleen acts as a blood filter and lymphopoietic organ. Asplenic and hyposplenic individuals are more susceptible to serious infections caused by encapsulated bacteria but they can be protected by antibiotic prophylaxis and immunizations. Recent progress in vaccinology means prophylaxis is now successful in the vast majority of serious infections with pneumococci, meningococci and Haemophilus influenzae type b responsible for the majority of cases of overwhelming sepsis in asplenic patients. Current guidelines are coherent. Physicians treating patients with conditions associated with hyposplenism are ethically obliged to immunize their patients using the vaccines currently available to protect them from largely preventable, life-threatening infections.

Laterality defects in the national birth defects prevention study (1998-2007): birth prevalence and descriptive epidemiology

Little is known epidemiologically about laterality defects. Using data from the National Birth Defects Prevention Study (NBDPS), a large multi-site case-control study of birth defects, we analyzed prevalence and selected characteristics in children born with laterality defects born from 1998 to 2007. We identified 517 nonsyndromic cases (378 heterotaxy, 73.1%; 139 situs inversus totalis [SIT], 26.9%) resulting in an estimated birth prevalence of 1.1 per 10,000 live births (95% confidence interval 1.0–1.2). Prevalence did not differ significantly across sites, over time, or by inclusion of pregnancy termination. Laterality defects were more common among preterm cases compared to term cases, and in children born to mothers who were non-white or younger than 20 years compared to white mothers or those age 25–29 years. The distribution of associated cardiac and extra-cardiac defects, excluding the expected heterotaxy anomalies, varied by type of laterality defect. Cases with heterotaxy were significantly more likely than those with SIT to have double outlet right ventricle, atrioventricular canal defects, pulmonary stenosis, non-tetralogy of Fallot pulmonary atresia with ventricular septal defect, totally and partially anomalous pulmonary venous return; also more likely to have orofacial clefts, esophageal atresia, bowel atresias, and omphalocele, though not reaching statistical significance. Relatively more common among cases with SIT were Dandy- Walker malformation, anotia/microtia, and limb deficiency. The similarity in the demographic characteristics of heterotaxy and SIT supports the hypothesis that they are part of a continuum of abnormal left-right axis patterning. These findings on laterality defects may help guide clinical care, future research, and prevention strategies.

Defects in laterality with emphasis on heterotaxy syndromes with asplenia and polysplenia: an autopsy case series at a single institution

Heterotaxy is a rare disease with high morbidity and mortality. Controversy exists over how to classify these syndromes with most cases stratified into asplenia/polysplenia syndromes or right/left isomerism. In an effort to review comprehensively specific pheonotypes associated with heterotaxy syndromes, we reviewed published cases series, adopted a classification scheme based on spleen status, and evaluated autopsy cases retrospectively with abnormal laterality at our institution. We categorized 116 cases as situs inversus totalis, polysplenia, asplenia, and single right-sided spleen. Cardiovascular abnormalities occurred in 87.1% of polysplenia, 90.5% of asplenia, and all cases of single right-sided spleen. For polysplenia, 48.9% had bilateral bilobed lungs, 87% had right-sided stomach, 58.1% had midline symmetric liver, and 60.4% had malrotated intestines. For asplenia, 51.9% had bilateral trilobed lungs, 86.7% had right-sided stomach, 45.8% had symmetric liver, and 65.5% had malrotated intestines. Atrioventricular septal defects occurred in 91.2% of asplenia compared to 56.8% of polysplenia cases. Eight percent had pulmonary/aortic stenosis or atresia. Double outlet right ventricle was more common in polysplenia (32.6%) compared to asplenia (21.4%). Total anomalous systemic venous return was described in 55.6% of polysplenia and total anomalous pulmonary venous connections in 81% of asplenia cases. Greater than half of the cases had no heterotaxy diagnosis. Although, we found similar heterotaxy-associated characteristics, the frequencies differed from previous studies. We found great variation in how heterotaxy-associated defects were described, diagnosed, and reported. Although there are known associated characteristics with the polysplenia/asplenia syndromes, correct identification requires a standardized approach for diagnosis and reporting.

Prevalence and risk factors for pulmonary hypertension in patients with hemoglobin E/β-thalassemia disease

OBJECTIVES

To find the prevalence and risk factors of pulmonary hypertension (PHT) in adult patients with hemoglobin E/β-thalassemia disease (E/β-Thal).

METHODS

One hundred and ten clinically stable E/β-Thal outpatients, sixty-one of whom had undergone splenectomy, were prospectively studied using their clinical profiles, selected blood tests, chest roentgenogram, and transthoracic echocardiogram. Based on the pulmonary artery systolic pressure (PASP) values estimated by the echocardiogram of ≥36 mmHg, they were dichotomized into those with (PHT+) and without (PHT-) PHT.

RESULTS

PHT was found in 41 (37.3%) patients without gender preponderance. It was not due to the left heart and was not severe (PASP = 46.3 ± 10.4 mmHg). PASP was higher in splenectomized patients (48.0 ± 11 vs. 40.3 ± 4.7 mmHg (P = 0.004)). PHT was found in 32 of 61 (52.5%) splenectomized patients, mostly (53%) in the second decade, and rarely (6.3%) during the first 5 yr after splenectomy. PHT+ patients had more hemolysis (P = 0.001-0.04 depending on the parameters), more asplenic cases (P < 0.001), and higher serum soluble vascular cell adhesion molecule-1 (sVCAM-1) and high-sensitivity C-reactive protein levels (P = 0.004 and 0.008, respectively). Strong risk factors by univariate analysis were serum sVCAM-1 levels ≥1600 ng/mL, serum cell-free Hb ≥ 3 mg/dL, asplenia, and amount of NRBCs/100 WBCs >40.

CONCLUSIONS

Prevalence of PHT in E/β-Thal patients was 37.3% without gender preponderance. Those with severe hemolysis and asplenia invariably had severer PHT. Strong risk factors were asplenia and associated markedly elevated values of sVCAM-1, cell-free Hb, and NRBCs in blood.

Bordetella holmesii bacteremia cases in the United States, April 2010-January 2011

We describe the first report of temporally related cases of Bordetella holmesii bacteremia. Demographic and clinical data were collected through chart abstraction and case-patient interviews. Twenty-two cases were identified from 6 states. Symptom onset dates ranged from April 2010 to January 2011. Median age of patients was 17.1 years and 64% had functional or anatomic asplenia. Pulsed-field gel electrophoresis profiles of a sample of isolates were identical. These cases occurred during a peak in pertussis outbreaks with documented cases of B. holmesii/Bordetella pertussis respiratory coinfection; whether there is a link between B. holmesii respiratory and bloodstream infection is unknown.

A case of Helicobacter cinaedi bacteremia in an asplenic patient

Helicobacter cinaedi is an enterohepatic species. It can cause bacteremia, gastroenteritis, and cellulitis, particularly in immunocompromised individuals, such as those with acquired immunodeficiency syndrome, malignancy, or alcoholism. There are no previous reports of H. cinaedi infection in Korea. A 71-yr-old man was admitted to the emergency room because of dyspnea on November 9, 2011. He had undergone splenectomy 3 yr ago because of immune hemolytic anemia. Chest plain radiography revealed bilateral pleural effusion. He developed fever on hospital day (HD) 21. Three sets of blood cultures were taken, and gram-negative spiral bacilli were detected in all aerobic vials. The isolate grew in tiny colonies on chocolate agar after 3-day incubation under microaerophilic conditions. This organism tested positive for catalase and oxidase, and negative for urease. The 16S rRNA gene sequence of this isolate exhibited 99.8% homology with the published sequence of H. cinaedi CCUG 18818^T (GenBank accession no. ABQT01000054) and 98.5% homology with the sequence of Helicobacter bilis Hb1^T (GenBank accession no. U18766). The patient was empirically treated with piperacillin/tazobactam and levofloxacin, and discharged with improvement on HD 31. To our knowledge, this is the first report of H. cinaedi bacteremia in an asplenic patient. Asplenia appears to be a risk factor for H. cinaedi bacteremia.

Heterotaxy: lessons learned about patterns of practice and outcomes from the congenital heart surgery database of the society of thoracic surgeons

According to The International Society for Nomenclature of Pediatric and Congenital Heart Disease (ISNPCHD), "Heterotaxy is synonymous with 'visceral heterotaxy' and 'heterotaxy syndrome'. Heterotaxy is defined as an abnormality where the internal thoraco-abdominal organs demonstrate abnormal arrangement across the left-right axis of the body. By convention, heterotaxy does not include patients with either the expected usual or normal arrangement of the internal organs along the left-right axis, also known as 'situs solitus', or patients with complete mirror-imaged arrangement of the internal organs along the left-right axis also known as `situs inversus'." or patients with complete mirror-image arrangement of the internal organs along the left-right axis, also known as situs inversus. The purpose of this article is to review the data about heterotaxy in the Society of Thoracic Surgeons (STS) Congenital Heart Surgery Database. The investigators examined all index operations in the STS Congenital Heart Surgery Database over 12 years from January 1, 1998 to December 31, 2009, inclusive. This analysis resulted in a cohort of 77 153 total index operations. Of these, 1505 operations (1.95%) were performed in patients with heterotaxy. Of the 1505 index operations performed in patients with heterotaxy, 1144 were in patients with asplenia and 361 were in patients with polysplenia. In every STS -EACTS Congenital Heart Surgery Mortality Category, discharge mortality is higher in patients with heterotaxy compared with patients without heterotaxy (EACTS = European Association for Cardio-Thoracic Surgery). Discharge mortality after systemic to pulmonary artery shunt is 6.6% in a cohort of all single-ventricle patients except those with heterotaxy, whereas it is 10.8% in single-ventricle patients with heterotaxy. Discharge mortality after Fontan is 1.8% in a cohort of all single-ventricle patients except those with heterotaxy, whereas it is 4.2% in single-ventricle patients with heterotaxy. The STS Congenital Heart Surgery Database is largest congenital heart surgery database in North America. This review of data from the STS Congenital Heart Surgery Database allows for unique documentation of practice patterns and outcomes. From this analysis, it is clear that heterotaxy is a challenging problem with increased discharge mortality in most subgroups.

Right isomerism with complex cardiac anomalies presenting with dysphagia--a case report

Isomerism or Heterotaxy syndromes are rare multifaceted congenital anomalies with multi-system involvement. Grouped under the broad category of Situs Ambiguous defects, these often pose diagnostic difficulties due to their varied and confusing anatomy. Since patients rarely survive into adulthood due to cardiovascular complications, the etiology and natural history of such conditions are not fully understood. Imaging provides the most accurate non invasive method for diagnosis and thereby, prognosis in such cases. We present a case of right sided Isomerism with complex cardiac anomalies in a 17 year old adolescent, who presented with dysphagia as one of the main complaints. Multi modality imaging demonstrated the intricate abnormalities in vital systems.

Human immunoglobulin M memory B cells controlling Streptococcus pneumoniae infections are generated in the spleen

Splenectomized and asplenic patients have a high incidence of infections by encapsulated bacteria and do not respond to polysaccharide vaccines. To understand whether the absence of the spleen is associated with a defined B cell defect, we analyzed B cell subsets in the peripheral blood. We found that a population of B cells known as immunoglobulin (Ig)M memory is lacking in patients without spleen. The absence of IgM memory B cells correlates with an impaired immune response to encapsulated bacteria not only in splenectomized patients, but also in individuals with an intact spleen. We show that the physiological and transient predisposition to pneumococcal infections of young children (0-2 yr) is associated with the lack of circulating IgM memory B cells and of serum antipolysaccharide IgM. We also demonstrate that IgM memory B cells are undetectable in a fraction of patients with common variable immunodeficiency, who have recurrent and invasive infections by encapsulated bacteria. IgM memory B cells, therefore, require the spleen for their generation and/or survival and are responsible for the protection against encapsulated bacteria.

B-1a B cells that link the innate and adaptive immune responses are lacking in the absence of the spleen

Splenectomized individuals are prone to overwhelming infections with encapsulated bacteria and splenectomy of mice increases susceptibility to streptococcal infections, yet the exact mechanism by which the spleen protects against such infections is unknown. Using congenitally asplenic mice as a model, we show that the spleen is essential for the generation of B-1a cells, a B cell population that cooperates with the innate immune system to control early bacterial and viral growth. Splenectomy of wild-type mice further demonstrated that the spleen is also important for the survival of B-1a cells. Transfer experiments demonstrate that lack of these cells, as opposed to the absence of the spleen per se, is associated with an inability to mount a rapid immune response against streptococcal polysaccharides. Thus, absence of the spleen and the associated increased susceptibility to streptococcal infections is correlated with lack of B-1a B cells. These findings reveal a hitherto unknown role of the spleen in generating and maintaining the B-1a B cell pool.