Asplenia Research Articles

Babesia Screening in the U.S. Blood Supply

Transmission of Babesia microti via transfusion of cellular blood products can cause severe infection in immunocompromised or asplenic patients.

Congenital Asplenia Revealed by Streptococcus oralis septicemia: Case Report

Congenital asplenia is a rare life-threatening condition, often presenting with sepsis caused by encapsulated pathogens. It may arise as part of situs abnormalities or result from an unrelated specific defect of spleen development. Isolated congenital asplenia is a very rare condition. We report a case of asplenia revealed by severe sepsis and multi-organ failure in a previously healthy 25-year-old male how had never undergone any surgical procedures. Blood cultures grew Streptococcus oralis four days after admission. Computed tomography revealed pneumonia and asplenia. The patient was finally diagnosed as Streptococcal sepsis revealing isolated congenital asplenia. Cephalosporin and levofloxacin were administered and the patient died following cardiopulmonary arrests. No family history for this condition was reported. Clinicians should pay attention to the congenital asplenia in Streptococcal disease, particularly in the event of overwhelming sepsis. In affected individuals, the use of appropriate antibiotic prophylaxis and immunisations could save lives.

A Retrospective Study of Invasive Bacterial Infections in Children with Asplenia

목적: 무비증 환자에서 높은 사망률을 보이는 침습성 세균 감염의 위험성은 잘 알려져 있으며 예방적 항생제 처방 및 특히 피막세균에 대한 예방접종이 강조된다. 최근 피막세균에 대한 국내 백신 영역에서 많은 변화가 있었으나 국내 무비증 소아청소년 환자의 현황과 침습성 세균 감염, 예방적 항생제 처방 및 예방접종의 실태에 관한 보고는 찾기 어렵다. 방법: 1997년 1월부터 2016년 12월까지 20년간 단일 3차 병원의 18세 이하 소아청소년 무비증 환자를 대상으로 후향적 의무기록 분석 기술 연구를 시행하였다. 결과: 총 213명의 소아청소년 무비증 환자 중 선천성 무비증은 114명(53.5%), 기능성 무비증은 58명 (27.2%)이었으며 나머지 41명(19.3%)은 후천성 무비증이었다. 비장절제술을 받은 중앙 연령은 12.2세(범위, 5.0-16.9세)였으며 수술의 가장 흔한 원인은 유전구형적혈구증(39.0%)이었다. 전체 무비증환자 중 16.4%만이 1년 이상 예방적 항생제를 유지하였고 항균제는 amoxicillin이 94.3%로 가장 흔하였으며 유지기간 중앙값은 41개월(범위, 12-161개월)이었다. 전체 무비증 환자 중 168명(78.9%)에서 예방접종력을 확인할 수 있었으며, 각 피막세균에 대한 예방접종률은 폐렴사슬알균이 44.1%, b형 인플루엔자균(Haemophilus influenzae type B)은 53.0%, 수막알균은 10.7%로 낮았고 3가지 백신을 모두 완료한 환자는 8.7%에 불과하였다. 연구 기간 동안 총 6명에서 6예(2.8%, 0.28/100인년)의 침습성 세균 감염증이 발생하였고 5예는 선천성 무비증, 1예는 기능성 무비증군에서 발생하였으며 발생 중 앙 연령은 15개월(범위, 4-68개월)이었다. 6예 중 5예는 균혈증, 1예는 뇌수막염이었고, 가장 흔한 균은 폐렴사슬알균(n=3)이었으며 그 외 H. influenzae 가 1예 있었다. 6예 중 3예(50.0%)가 사망하였고 모두 폐렴사슬알균 균혈증이었다. 6예 모두 예방적 항생제를 처방받지 않았고 예방접종력을 확인할 수 있었던 4예 중 1예만 Hib의 접종을 완료하였으나 나머지 모두는 피막세균 예방접종을 전혀 받지 않았다. 결론: 무비증 환자에서 높은 사망률을 보이는 침습성 세균 감염의 위험은 전통적으로 잘 알려져 있음에 도 불구하고 적절한 예방적 항생제 처방 및 필수 예방접종률은 여전히 낮은 수준이다. 따라서 임상 의 사는 무비증 환자의 정기적 추적 관찰뿐만 아니라 적절한 예방적 항생제 및 필수 예방접종에 대해 숙지 할 필요가 있다.

Recommendations for Use of Meningococcal Conjugate Vaccines in HIV-Infected Persons - Advisory Committee on Immunization Practices, 2016.

At its June 2016 meeting, the Advisory Committee on Immunization Practices (ACIP) recommended routine use of meningococcal conjugate vaccine (serogroups A, C, W, and Y; including MenACWY-D [Menactra, Sanofi Pasteur] or MenACWY-CRM [Menveo, GlaxoSmithKline]) for persons aged ≥2 months with human immunodeficiency virus (HIV) infection. ACIP has previously recommended routine vaccination of persons aged ≥2 months who have certain medical conditions that increase risk for meningococcal disease (1), including persons who have persistent (e.g., genetic) deficiencies in the complement pathway (e.g., C3, properdin, Factor D, Factor H, or C5-C9); persons receiving eculizumab (Soliris, Alexion Pharmaceuticals) for treatment of atypical hemolytic uremic syndrome or paroxysmal nocturnal hemoglobinuria (because the drug binds C5 and inhibits the terminal complement pathway); and persons with functional or anatomic asplenia (including persons with sickle cell disease). Routine vaccination with meningococcal conjugate vaccine is also recommended for all healthy adolescents in the United States (1). This report summarizes the evidence considered by ACIP in recommending vaccination for HIV-infected persons, and provides recommendations and guidance for use of meningococcal conjugate vaccines (serogroups A, C, W, and Y) among HIV-infected persons aged ≥2 months; the majority of meningococcal disease among HIV-infected persons is caused by these four serogroups.

Recommendations for Serogroup B Meningococcal Vaccine for Persons 10 Years and Older.

This policy statement provides recommendations for the prevention of serogroup B meningococcal disease through the use of 2 newly licensed serogroup B meningococcal vaccines: MenB-FHbp (Trumenba; Wyeth Pharmaceuticals, a subsidiary of Pfizer, Philadelphia, PA) and MenB-4C (Bexsero; Novartis Vaccines, Siena, Italy). Both vaccines are approved for use in persons 10 through 25 years of age. MenB-FHbp is licensed as a 2- or 3-dose series, and MenB-4C is licensed as a 2-dose series for all groups. Either vaccine is recommended for routine use in persons 10 years and older who are at increased risk of serogroup B meningococcal disease (category A recommendation). Persons at increased risk of meningococcal serogroup B disease include the following: (1) persons with persistent complement component diseases, including inherited or chronic deficiencies in C3, C5-C9, properdin, factor D, or factor H or persons receiving eculizumab (Soliris; Alexion Pharmaceuticals, Cheshire, CT), a monoclonal antibody that acts as a terminal complement inhibitor by binding C5 and inhibiting cleavage of C5 to C5A; (2) persons with anatomic or functional asplenia, including sickle cell disease; and (3) healthy persons at increased risk because of a serogroup B meningococcal disease outbreak. Both serogroup B meningococcal vaccines have been shown to be safe and immunogenic and are licensed by the US Food and Drug Administration for individuals between the ages of 10 and 25 years. On the basis of epidemiologic and antibody persistence data, the American Academy of Pediatrics agrees with the Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention that either vaccine may be administered to healthy adolescents and young adults 16 through 23 years of age (preferred ages are 16 through 18 years) to provide short-term protection against most strains of serogroup B meningococcal disease (category B recommendation).

Pneumococcal vaccination coverages among low-, intermediate-, and high-risk adults in Catalonia

ABSTRACTThere is scarce data about pneumococcal vaccination coverages among adults in recent years. We investigated current pneumococcal vaccination coverages in Catalonia, Spain, with a cross-sectional population-based study including 2,033,465 individuals aged 50 y or older assigned to the Catalonian Health Institute at 01/01/2015 (date of survey). A previously validated institutional research clinical Database was used to classify study subjects by their vaccination status for both 23-valent pneumococcal polysaccharide vaccine (PPSV23) and 13-valent pneumococcal conjugate vaccine (PCV13), to identify comorbidities and underlying conditions, and establish the risk stratum of each individual: High risk stratum: functional or anatomic asplenia, cochlear implants, CSF leaks, or immunocompromising conditions; medium risk stratum: immunocompetent persons with history of chronic cardiac or respiratory disease, liver disease, diabetes mellitus, alcoholism and/or smoking; low risk stratum: persons without high or medium risk conditions. Of the total 2,033,465 study population, an amount of 789,098 (38.8%) had received PPVS23, whereas 5031 (0.2%) had received PCV13. PPSV23 coverages increased largely with increasing age: 4.8% in 50–59 y vs 35.5% in 60–69 y vs 71.9% in 70–79 y vs 79.5% in 80 y or older; p < 0.001). PCV13 coverages also increased with age, although they were very low in all age groups. PPSV23 coverages were 59.2% in high risk stratum, 48.3% in medium risk stratum and 28.1% in low risk stratum (p < 0.001). For the PCV13, uptakes were 1.2%, 0.3% and 0.1% in high, medium and low stratum, respectively (p < 0.001). In conclusion, pneumococcal vaccination coverages in Catalonian adults are not optimal, being especially small for the PCV13 (even in high-risk subjects).

Vaccinations for immunocompromised hosts – focussing on patients after a hematological stem cell or organ transplantation, with HIV or with functional or anatomical asplenia

Patients with an acquired immune deficiency, for example due to HIV-infection, after a solid organ or haematological stem cell transplantation or due to functional or anatomical asplenia, have a greater risk to experience severe complications or a chronic course of infection compared to healthy individuals. Vaccinations would pose an ideal primary preventive method. However, their efficacy is reduced if applied during the immunosuppressed period. Therefore, whenever possible, vaccinations should be administered before the period of immunosuppression starts – or caught up later during the period of minimal possible immunosuppression. Nevertheless, the benefit conveyed through vaccines is undisputed, particularly if indications regarding dosing of vaccines (amount and frequency of doses) are optimized according to the given state of immunosuppression. Live attenuated vaccines are contraindicated during severe immunosuppression. Serologies should still be analysed and documented however, since these vulnerable patients require passive immunization through specific or standard intravenous immunoglobulins in case of relevant exposure to the respective antigens. For all patients therefore, careful documentation and communication of previous vaccinations and serologies (protective or not) among the various medical specialties is required to optimize patient management. For all immunosuppressed patients the efficacy of polysaccharide vaccines (such as the pneumococcal and meningococcal vaccines PSV-23 and MPV-ACWY) is strongly reduced compared to the conjugated ones (PCV13 and MCV-ACWY). Therefore, contrary to most other national guidelines, the Swiss guidelines recommend to use only the conjugated versions in primary vaccination series as well as in boosters – this applies strongly for immunosuppressed patients, but is recommended also for the general population in Switzerland. Another common management recommendation specific for transplant patients is the indication to control vaccine efficacy by measuring titers. This is also indicated for hepatitis B in HIV-positive patients, but not required for any vaccine in asplenic patients. In summary, vaccines pose an important opportunity for primary and secondary prevention for vulnerable patients at highest risk of experiencing the worst forms of the diseases to be prevented.

Transcription factor TLX1 controls retinoic acid signaling to ensure spleen development.

The molecular mechanisms that underlie spleen development and congenital asplenia, a condition linked to increased risk of overwhelming infections, remain largely unknown. The transcription factor TLX1 controls cell fate specification and organ expansion during spleen development, and Tlx1 deletion causes asplenia in mice. Deregulation of TLX1 expression has recently been proposed in the pathogenesis of congenital asplenia in patients carrying mutations of the gene-encoding transcription factor SF-1. Herein, we have shown that TLX1-dependent regulation of retinoic acid (RA) metabolism is critical for spleen organogenesis. In a murine model, loss of Tlx1 during formation of the splenic anlage increased RA signaling by regulating several genes involved in RA metabolism. Uncontrolled RA activity resulted in premature differentiation of mesenchymal cells and reduced vasculogenesis of the splenic primordium. Pharmacological inhibition of RA signaling in Tlx1-deficient animals partially rescued the spleen defect. Finally, spleen growth was impaired in mice lacking either cytochrome P450 26B1 (Cyp26b1), which results in excess RA, or retinol dehydrogenase 10 (Rdh10), which results in RA deficiency. Together, these findings establish TLX1 as a critical regulator of RA metabolism and provide mechanistic insights into the molecular determinants of human congenital asplenia.

Advisory Committee on Immunization Practices Recommended Immunization Schedule for Adults Aged 19 Years or Older — United States, 2016

I October 2015, the Advisory Committee on Immunization Practices (ACIP) approved the Recommended Adult Immunization Schedule: United States, 2016. This schedule summarizes ACIP recommendations for the use of vaccines routinely recommended for adults in 2 figures (Figures 1 and 2), footnotes for each vaccine (Figure 3), and a table that describes primary contraindications and precautions for commonly used vaccines for adults (Table). Details on these updates and information on other vaccines recommended for adults can be found at www.cdc.gov/vaccines/schedules. The full ACIP recommendations for each vaccine are not included in the schedule owing to space limitations but can be found at www.cdc.gov/vaccines/hcp/acip-recs /index.html. The 2016 adult immunization schedule was reviewed and approved by the American College of Physicians, American Academy of Family Physicians, American College of Obstetricians and Gynecologists, and American College of Nurse-Midwives. Changes in the 2016 adult immunization schedule from the 2015 schedule include the following new ACIP recommendations: Y Interval change for 13-valent pneumococcal conjugate vaccine (PCV13) followed by 23-valent pneumococcal polysaccharide vaccine (PPSV23) from “6 to 12 months” to “at least 1 year” for immunocompetent adults aged ≥65 years (1). Adults aged ≥19 years with anatomical or functional asplenia, cerebrospinal fluid leak, or cochlear implant or who are immunocompromised should receive PPSV23 at least 8 weeks after PCV13. Y Serogroup B meningococcal (MenB) vaccine series should be administered to persons aged ≥10 years who are at increased risk for serogroup B meningococcal disease (2). Those at increased risk include persons with anatomical or functional asplenia or persistent complement component deficiencies, microbiologists who are routinely exposed to isolates of Neisseria meningitidis, and persons identified at increased risk because of a serogroup B meningococcal disease outbreak. MenB vaccine series may be administered to adolescents and young adults aged 16 through 23 years (preferred age is 16 through 18 years) to provide short-term protection against most strains of serogroup B meningococcal disease (3). Y Nine-valent human papillomavirus (HPV) vaccine (9vHPV) was added to the 2016 adult immunization schedule. This vaccine can be used for routine vaccination against HPV as 1 of 3 HPV vaccines (bivalent HPV vaccine [2vHPV], quadrivalent HPV vaccine [4vHPV], and 9vHPV) recommended for females and 1 of 2 HPV vaccines (4vHPV and 9vHPV) recommended for males (4). Notable changes in Figures 1 and 2 are as follows: Y The row for “Meningococcal” was retitled to “Meningococcal 4-valent conjugate (MenACWY) or polysaccharide (MPSV4)” to indicate that there are 2 types of serogroup A, C, W, and Y meningococcal vaccines available for adults. Y A new row for “Meningococcal B (MenB)” was added. Y Additional text was added in several indication bars to describe reasons for alternate dosing schedules for vaccines where such designations were appropriate; for example, in the “Measles, mumps, and rubella (MMR)” indication bar that states “1 or 2 doses,” the clause “depending on indication” was added. Y The text in the “Hepatitis A” indication bar was revised from “2 doses” to “2 or 3 doses depending on vaccine” to account for the hepatitis A and hepatitis B combination vaccine that is administered in a 3-dose series. Additional clarifying changes in Figure 2 include: Y The text in the consolidated “Influenza” indication bar was simplified to “one dose annually”; readers should refer to the footnotes for additional information regarding which influenza vaccine types are recommended for different age and risk groups. Y The text in the “Pneumococcal polysaccharide (PPSV23)” indication bar was revised from “1 or 2 doses” to “1, 2, or 3 doses depending on indication” to account for the recommendation that adults aged ≥19

A case of right sided cardiosplenic heterotaxy syndrome

Heterotaxy is said to exist when the internal thoracoabdominal organs demonstrate abnormal arrangement across the left-right axis of the body. It is categorized into asplenia and polysplenia syndrome variants. Asplenia syndrome is characterized by complex congenital heart defects, asplenia and abdominal heterotaxy. Evidence with regard to the incidence of isomerism is sparse. However, recent studies show that it is commoner in Asians compared to Western populations. Most cases of right isomerism are recognized in early infancy because of the presence of severe forms of complex cyanotic heart disease. Infants with right isomerism invariably have obstruction of the pulmonary outflow tract, as well as common mixing at atria and ventricles, and pulmonary atresia is present in 67% of cases. Here we report an unusual and relatively late presentation of an infant with right sided cardiosplenic heterotaxy syndrome associated with severe cyanotic congenital heart disease.

A Dutch nationwide survivorship care program for Hodgkin lymphoma survivors.

6 Background: Survivors of Hodgkin lymphoma (HL) are at increased risk of various late adverse effects of treatment, leading to substantial excess morbidity and mortality. Long-term follow-up care programs have been established for childhood cancer survivors, but not yet for HL survivors. The Dutch BETER consortium (Better care after Hodgkin lymphoma: Evaluation of long-term Treatment Effects and screening Recommendations) has developed a nationwide infrastructure for Survivorship Care Clinics for HL survivors. The consortium aims to: 1) establish follow-up guidelines for survivors; 2) identify survivors eligible for follow-up care; 3) educate survivors about late adverse treatment effects; and 4) provide risk-based care. Methods: Evidence-based follow-up guidelines were developed according to international standards. The guideline development group consisted of clinicians, methodological experts and patient representatives. To be eligible for follow-up care patients must have survived ≥ 5 yrs and have been treated at ages 15-70 years after 1969. Survivors were identified through the Netherlands Cancer Registry and hospital-based registries. Tracing of current addresses was done through the nationwide database of Municipal Offices. Results: We developed guidelines forsecond malignancies, cardiovascular disease, thyroid disease, osteoporosis and functional asplenia infection prophylaxis. Recommendations are given for fertility care and therapy for neck muscle weakness. We have identified and traced a cohort of 12,000 HL survivors in 23 centers, covering about 80% of HL patients in the Netherlands, of whom 8,500 appear to be eligible for follow-up care. For all survivors, treatment data were collected from the medical records to provide risk-based screening recommendations. A website and a survivorship care plan were developed to educate survivors about late effects. A nationwide database, including screening and adverse events data, is in development to evaluate the follow-up guidelines for diagnostic value and efficacy. Conclusions: We expect that the BETER project will improve healthy life expectancy of HL survivors. Evaluation of follow-up care will lead to a more evidence-based follow-up program.

Prevalence of High-Risk Underlying Conditions for Pneumococcal Disease Among People Over 50 Years in Catalonia, Spain

Background: Published data on the frequency and distribution of high-risk factors for pneumococcal disease are limited. This study investigated the prevalence of high-risk underlying conditions for pneumococcal disease among people over 50 years in Catalonia, Spain. Methods: Cross-sectional population-based study including 2,033,465 individuals aged 50 years or older registered at 01/01/2015 in the Catalonian Health Institute. A previously validated institutional research clinical Database was used to identify high-risk conditions to suffer pneumococcal disease (functional or anatomic asplenia, cochlear implants, cerebrospinal fluid [CSF] leaks and/or immunocompromising conditions). Prevalence of risk conditions was compared according to gender and age strata. Results: Of the total 2,033,465 study population, an amount of 176,600 persons (8.7%) had any high-risk condition. Prevalence of high-risk subjects did not substantially differ by gender (9.2% in men vs. 8.2% in women; p<0.001), but considerably increased with increasing age (5.1% in 50-64 years vs. 10.6% in 65-79 years vs. 16.1% in people 80 years or older; p<0.001). Overall, 294 individuals (<0.1%) had anatomical or functional asplenia, 76 (<0.1%) cochlear implants, 41 (<0.1%) CSF leaks, 3,854 (0.2%) had immunodeficiency/AIDS, 16,815 (0.8%) had severe renal disease (nephrotic syndrome or renal failure), 5,034 (0.2%) had received bone marrow transplantation, 103,948 (5.1%) had recent cancer (diagnosed within 5 prior years) and 72,040 (3.5%) received immunosuppressive medication/radiotherapy. Conclusion: In our setting, almost ten percent of people over 50 years have any high-risk factor for pneumococcal vaccination, basically immunocompromising conditions.

Organoaxial gastric volvulus with diaphragmatic eventration and wandering spleen: an unusual association

Organoaxial gastric volvulus occurs when the stomach rotates around a transverse line between the pylorus and gastroesophegeal junction. It is potentially life threatening because delayed diagnosis and treatment may result in perforation, infarction and gangrene of stomach. As it is a rare entity high index of suspicion is required to prevent high morbidity and mortality. Primary Gastric volvulus has been seen in association with congenital asplenia or "wandering spleen" or with diaphragmatic hernia or diaphragmatic eventration. We report a case of 17 year female (perhaps the first in literature) who had wandering spleen, diaphragmatic eventration and gastric volvulus a congenital anomaly rare to find and a brief review of literature.

Immunization for Patients with Asplenia: Importance and Recommendations

The spleen is an important component of the lympho-hematopoietic complex system, playing a relevant role in the defense against infections. Patients with functional or anatomic asplenia have an increased susceptibility to infections related to the absence or reduction of splenic function. This group of patients is particularly vulnerable to encapsulated bacteria. Therefore, the infectious complications associated with these pathogens are the most threatening in the scenario of spleen function impairment. Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae type b are encapsulated bacteria and are considered to be the main factors responsible for infections with high morbidity and mortality in asplenic patients. Thus, immunization against these microorganisms is an indispensable strategy in order to ensure the survival of these individuals.

Vacunas antineumocócicas. Nuevas vacunas conjugadas para el adulto

Pneumococcal infections are a significant cause of morbidity and mortality, and are one of the 10 leading causes of death worldwide. Children under 2 years have a higher incidence rate, followed by adults over 64 years. The main risk group are individuals with immunodeficiency, and those with anatomical or functional asplenia, but can also affect immunocompetent persons with certain chronic diseases. Significant progress has been made in the last 10 years in the prevention of these infections. Until a few years ago, only the 23-valent non-conjugate pneumococcal vaccine was available. Its results were controversial in terms of efficacy and effectiveness, and with serious limitations on the type of immune response induced. The current possibility of using the 13-valent conjugate vaccine in adults has led to greater expectations in improving the prevention of pneumococcal disease in these age groups.

Summary of the National Advisory Committee on Immunization's Statement on the re-immunization with polysaccharide 23-valent pneumococcal vaccine.

Individuals who are 2 years of age and over and at high risk for invasive pneumococcal disease (IPD) (defined as those with functional or anatomic asplenia or sickle cell disease; hepatic cirrhosis; chronic renal failure or nephrotic syndrome; HIV infection; and immunosuppression related to disease or therapy) are recommended to receive one lifetime booster dose of polysaccharide 23-valent pneumococcal vaccine (Pneu-P-23) vaccine, in addition to age- and risk-specific recommendations for the conjugate 13-valent pneumococcal vaccine (Pneu-C-13). Adults aged 65 years and over are also considered at high risk for invasive pneumococcal disease (IPD). To determine the optimal time between initial vaccination with Pneu-P-23 and subsequent booster doses to protect against IPD in those at high risk for IPD. The National Advisory Committee on Immunization (NACI) conducted a systematic review of the literature on booster doses of pneumococcal vaccine for individuals at high risk for IPD disease. NACI reviewed the evidence considering the target population, safety, immunogenicity, efficacy, effectiveness of the vaccines, vaccine schedules, and other aspects of the overall immunization strategy, and then approved three specific recommendations. For all individuals aged 2 years and over who are at high risk for IPD and who have received a dose of Pneu-P-23, re-vaccination with a second dose of Pneu-P-23 should be provided five years after the initial dose of Pneu-P-23. They should also have previously received age-appropriate doses of 13-valent conjugate pneumococcal vaccine. There is currently insufficient evidence to determine the optimal timing and number of Pneu-P-23 boosters in high-risk adults. One lifetime booster of Pneu-P-23 is currently recommended for individuals at high risk for IPD, five years after the previous dose. Given the increased risk of IPD in adults aged 65 years and older and the rapid decline in antibodies following Pneu-P-23, all individuals should receive one dose of Pneu-P-23 at age 65 years-as long as five years have passed since the previous Pneu-P-23 dose. No additional booster dose is currently recommended for this age group, if they have no medical conditions that put them at high risk for IPD. The new and complete set of current recommendations for pneumococcal vaccines will be published in the updated "Pneumococcal" chapter in the Canadian Immunization Guide in the near future.

Severe Legionnaires’ Disease Complicated by Rhabdomyolysis and Clinically Resistant to Moxifloxacin in a Splenectomised Patient: Too Much of a Coincidence?

We here report a case of Legionnaires' disease in a splenectomised patient, complicated by rhabdomyolysis and acute renal failure and characterized by a poor clinical response to moxifloxacin. Splenectomy is not included among the factors, typically associated with higher risk or mortality in patients with Legionellosis. However, our report is consistent with previous case reports describing severe Legionella infections in asplenic subjects. The possibility that functional or anatomic asplenia may be a factor predisposing to severe clinical course or poor response to therapy in patients with Legionella infection cannot be excluded, deserving further investigation in the future. More studies are required in order to clarify the underlying pathophysiological mechanisms that connect asplenia, immunological response to Legionella, and pathogen's resistance to antibiotics.

Déficit en sphingomyélinase acide et rupture splénique : splénectomie ou traitement conservateur ?

IntroductionAcid sphingomyelinase deficiency leads to a severe infantile disease (Niemann-Pick disease type A) or an attenuated form of the disease encountered in adults (Niemann-Pick type B), including pulmonary fibrosis and splenomegaly. Case reportA 52-year-old man with Niemann-Pick disease type B was admitted with splenic rupture. Embolization of the splenic artery was initially performed. Three months later, the splenic volume had increased and functional asplenia was diagnosed. Splenic scintigraphy showed 20% of functional splenic tissue. Splenectomy was finally performed because of complete necrosis of the spleen. ConclusionDespite its theoretical contra-indication in Niemann-Pick disease due to a risk of respiratory insufficiency, splenectomy must sometimes be considered.

Delayed Treatment of a Dog Bite Resulting in Devastating Capnocytophaga Sepsis in an Alcoholic Patient With Functional Asplenia

Capnocytophaga canimorsus is a slow-growing gram-negative rod found in the normal oral flora of 20% to 25% of dogs. It is usually transmitted to humans by dog bite or exposure, causing symptoms ranging from local wound irritation to sepsis, meningitis, and death. Asplenia, alcohol abuse, and steroid use are risk factors for invasive disease, but this infection also occurs in the normal host.

Altered translation of GATA1 in Diamond-Blackfan anemia.

Ribosomal protein haploinsufficiency occurs in diverse human diseases including Diamond-Blackfan anemia (DBA),1,2 congenital asplenia,3 and T-cell leukemia.4 Yet how mutations in such ubiquitously expressed proteins result in cell-type and tissue specific defects remains a mystery.5 Here, we show that GATA1 mutations that reduce full-length protein levels of this critical hematopoietic transcription factor can cause DBA in rare instances. We show that ribosomal protein haploinsufficiency, the more common cause of DBA, can similarly reduce translation of GATA1 mRNA - a phenomenon that appears to result from this mRNA having a higher threshold for initiation of translation. In primary hematopoietic cells from patients with RPS19 mutations, a transcriptional signature of GATA1 target genes is globally and specifically reduced, confirming that the activity, but not the mRNA level, of GATA1 is reduced in DBA patients with ribosomal protein mutations. The defective hematopoiesis observed in DBA patients with ribosomal protein haploinsufficiency can be at least partially overcome by increasing GATA1 protein levels. Our results provide a paradigm by which selective defects in translation due to mutations in ubiquitous ribosomal proteins can result in human disease.