Asplenia
| Asplenia | |
| ICD-10 | D73.0, Q89.0 |
|---|---|
| ICD-9 | 289.59, 759.01 |
| OMIM | 208530 %271400 208540 |
|
Asplenia Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
Case Studies |
|
Asplenia On the Web |
|
American Roentgen Ray Society Images of Asplenia |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief:
Synonyms and keywords:
Overview
Historical Perspective
- In 1919, Morris and Bullock provided initial experimental evidence of the protective role of the spleen against infections.
- In 1952, King and Schumacker reported a series of cases of overwhelming post-splenectomy infections (OPSI) caused by encapsulated bacteria.
- In 1955, Rowley has demonstrated that splenectomized human beings fail to respond with a significant rise in antibody titer when an antigen is given intravenously.
- In 1969, Pearson et al,from USA, was the first to discover the term functional hypoplasia, a few decades ago when he identified some children suffering from sickle cell disease, who presented with the same clinical course as in splenectomised patients.
Classification
Pathophysiology
Physiology
The spleen consists of three functional inter-related compartments: red pulp, white pulp, marginal zone. The red pulp is a sponge-like structure filled with blood flowing through sinuses and cords functions as a filter for blood elements.[1] The white pulp consists primarily of lymphatic tissue creating structures called germinal centers which contain lymphocytes (activated B-lymphocytes among others), macrophages, and dendritic cells. They are situated in direct contact with splenic arterioles, branches of the splenic artery. Another region of the white pulp is that the periarteriolar lymphatic sheath, which consists of nodules containing mostly B lymphocytes. The marginal zone surrounds the white pulp and consists of blood vessels, macrophages, and specialized B cells.[2] The primary physiologic role of spleen is the filtration and processing of senescent blood cells, predominantly red blood cells and immunologically helps protect against encapsulated microorganisms and response to infectious pathogens. It contains both hematopoietic and lymphopoietic elements, which provides a basis for extramedullary hematopoiesis when necessary.
Pathology
It is understood that Asplenia is a variety of clinical settings, and it can refer to an anatomic absence of the spleen or functional asplenia secondary to a variety of disease states. The absence of a spleen is a well-known risk factor for severe bacterial infections, especially due to encapsulated bacteria. The spleen contains 2 types of tissues: white pulp and red pulp. The white pulp is rich in T-cell lymphocytes, naïve B-cell lymphocytes, and macrophages. The antigen-presenting cells (APC) can enter the white pulp and activate T cells, which in turn activate naïve B cells and differentiate into plasma cells that generate immunoglobulin M antibodies followed by immunoglobulin G antibodies. B cells can also act as antigen-presenting cells and has a phagocytic function to help opsonize encapsulated bacteria. About half of the total B cells in the blood express the memory marker CD27 and carry somatic mutations, and are therefore thought to be memory B cells. There are two types of memory B cells in human beings: switched memory B cells and IgM memory B cells. Switched memory B cells, which are the final product of germinal center reactions, produce high-affinity antibodies and have a protective function against infection. IgM memory B cells, need the spleen for their survival and generation and have the ability to produce natural antibodies. They also produce antibodies against Streptococcus pneumonia, Neisseria meningitidis, and Haemophilus influenzae type b. They can initiate T-cell-independent immune responses on infection or vaccination with capsular polysaccharide antigens.[1] The red pulp has macrophages and is responsible for filtering damaged, older red blood cells as well as phagocytosing opsonized bacteria. Due to this role of removing damaged erythrocytes, the spleen also plays an important role in the defense against intraerythrocytic parasitic infections such as malaria and Babesia.[3]
Causes
Asplenia is caused by either congenital, acquired conditions, or functional.
Common Causes
Acquired
- Acquired asplenia associated after trauma or surgery, is one of the commonest cause of the absence of splenic tissue.[4]
- Functional asplenia include diseases such as sickle cell disease, celiac disease, alcoholic liver disease, hepatic cirrhosis, lymphomas, and autoimmune disorders.[2]
Less Common Causes
Congenital
- Congenital asplenia may be isolated or usually seen as a clinical syndrome such as ivemark syndrome. This syndrome is classified under heterotaxy syndrome. It is associated with malformation of the heart, and abnormal arrangements of organs of the chest and abdomen along with asplenia or hypoplasia of the spleen.
- Isolated asplenia are rare and etiology was genetic, due to mutations in the gene RPSA, which encodes ribosomal protein SA, cause more than half of the cases of isolated congenital asplenia, which was first discovered in 2013.
- In heterotaxy syndrome Two human genes, connexin 43 and ZIC3, have been shown to be involved.
- congenital asplenia a very rare anomaly that has been reported in both infants and adults.
- Infantile cases are almost invariably associated with serious congenital malformations of the cardiovascular, gastrointestinal, and pulmonary systems that are not compatible with long life.
- These include atrioventricular communist, pulmonary stenosis or atresia, anomalies of the aorta and great vessels, complete or partial situs in versus, anomalies of the mesenteric and accessory lobes of the lungs.
- In the adult splenic agenesis is usually an isolated and unexpected finding.[5]
Differentiating Asplenia from other Diseases
Epidemiology and Demographics
Risk Factors
Common Risk Factors
- Common risk factors in the development of asplenia include:
Less Common Risk Factors
- Less common risk factor include:
- mutations in the gene RPSA, is a risk factor for Isolated asplenia.[7]
- Two human genes, connexin 43 and ZIC3, is a risk factor for heterotaxy syndrome.[8]
Screening
Natural History, Complications and Prognosis
Natural History
- If left untreated, Patients with asplenia or hyposplenia are at risk of life-threatening infection.
- Overwhelming post-splenectomy infection (OPSI) occurs in 5% of patients and has a mortality rate of 38%–70%.
- Patients with functional asplenia and hyposplenia who have not undergone a splenectomy can present with a life-threatening infection comparable to an OPSI
Diagnosis
Diagnostic study of choice | History and Symptoms | Physical Examination | Laboratory Findings | Electrocardiogram | X-Ray Findings | Echocardiography and Ultrasound | CT-Scan Findings | MRI Findings | Other Imaging Findings | Other Diagnostic Studies
Treatment
Primary prevention
- Vaccination against these encapsulated bacteria is recommended to prevent asplenia patients from severe infection. Up to 87% of asplenic patients were found to have been infected with Streptococcus pneumoniae, one of the most common bacterial pathogen leading to infection in patients with asplenia.
- Vaccinations are also recommended before splenectomy and after the surgical removal. For those with functional asplenia or autosplenectomy, it is also advised to continue aggressive vaccination schedules. It is recommended that patients should be given the pneumococcal conjugate vaccine (PCV-13) 8 weeks in advance, as well as the pneumococcal polysaccharide vaccine (PPSV-23), Haemophilus influenzae type B vaccine (Hib), and the quadrivalent meningococcal conjugate vaccine 14 days before planned surgery for splenectomy.
Secondary prevention
Effective measures for the secondary prevention of asplenia include:
- Patient should carry an alert card or bracelet and an up-to-date vaccination record.[9]
- Adult with asplenia, if unable to seek medical attention within 2 hours, should have access to preprescribed antibiotics which should be taken at fever onset.
- The risk of infection can be significantly reduced by using systematic, long-term approaches to care for asplenic patients.
- Patient and family education program that addresses the risk of infection in these at-risk patients.[3]
Case Studies
Template:Hematology Template:Phakomatoses and other congenital malformations not elsewhere classified
de:Asplenie
nl:Asplenie
fi:Asplenia
- ↑ 1.0 1.1 Di Sabatino A, Carsetti R, Corazza GR (2011) Post-splenectomy and hyposplenic states. Lancet 378 (9785):86-97. DOI:10.1016/S0140-6736(10)61493-6 PMID: 21474172
- ↑ 2.0 2.1 Kirkineska L, Perifanis V, Vasiliadis T (2014). dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=25125944 "Functional hyposplenism" Check
|url=value (help). Hippokratia. 18 (1): 7–11. PMC 4103047. PMID 25125944. - ↑ 3.0 3.1 Lee GM (2020). "Preventing infections in children and adults with asplenia". Hematology Am Soc Hematol Educ Program. 2020 (1): 328–335. doi:10.1182/hematology.2020000117. PMC 7727556 Check
|pmc=value (help). PMID 33275684 Check|pmid=value (help). - ↑ 4.0 4.1 Erdem SB, Genel F, Erdur B, Ozbek E, Gulez N, Mese T (2015). "Asplenia in children with congenital heart disease as a cause of poor outcome". Cent Eur J Immunol. 40 (2): 266–9. doi:10.5114/ceji.2015.52841. PMC 4637402. PMID 26557043.
- ↑ MYERSON RM, KOELLE WA (1956). "Congenital absence of the spleen in an adult; report of a case associated with recurrent Waterhouse-Friderichsen syndrome". N Engl J Med. 254 (24): 1131–2. doi:10.1056/NEJM195606142542406. PMID 13322226.
- ↑ Browning MG, Bullen N, Nokes T, Tucker K, Coleman M (2017). "The evolving indications for splenectomy". Br J Haematol. 177 (2): 321–324. doi:10.1111/bjh.14060. PMID 27018168.
- ↑ Bolze A (2014). "[Connecting isolated congenital asplenia to the ribosome]". Biol Aujourdhui. 208 (4): 289–98. doi:10.1051/jbio/2015001. PMID 25840456.
- ↑ Ahmed SA, Zengeya S, Kini U, Pollard AJ (2010). "Familial isolated congenital asplenia: case report and literature review". Eur J Pediatr. 169 (3): 315–8. doi:10.1007/s00431-009-1030-0. PMID 19618213.
- ↑ O'Neill NE, Baker J, Ward R, Johnson C, Taggart L, Sholzberg M (2020). "The development of a quality improvement project to improve infection prevention and management in patients with asplenia or hyposplenia". BMJ Open Qual. 9 (3). doi:10.1136/bmjoq-2019-000770. PMC 7410002 Check
|pmc=value (help). PMID 32759171 Check|pmid=value (help).