Congenital Asplenia by HC120221235852

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									Congenital Asplenia
    ISAT 351
     03/13/03

   Written by:
  Neesha Patel
 Kevin McArthur
  Pam Brinker
   Adam Neff
 Justin Chapman
                              Congenital Asplenia
Immune Cells That are Involved

        This deficiency is involved with both the
reticuloendothelial (RES) system and adaptive immunity by
the congenital absence of a spleen. The main defect is the
loss of mononuclear phagocytes. This process clears
pathogenic organisms from the blood. Also, there is a loss
of B and T cell mass, which may be largely compensated at
the level of systemic lymphoid tissue. In terms of the loss       Picture of a broken
of mononuclear phagocytes, T cell function is                     Spleen taken from
systematically impaired for a time after a therapeutic            http://faculty.purduenc.e
                                                                  du/jcamp/pigfold/abdom
splenectomy. The loss of B cell mass can result in a              en.html
noticeable but clinically significant decrease in total
immunoglobin levels.

Immune Response that causes symptoms and principles of the immune system

As stated above, the loss of mononuclear phagocytes causes this disease to occur. In
terms of specific antibody responses to antigen, the route of antigen exposure is critical to
the response. The route that favor lymphatic accumlation of antigen produce antibody
titers. The hematogenous exposure results in absent antibodies against specific antigens.
This occurs because there is no splenic lymphoid tissue to process the antigen and present
for T-B cell interaction. The lack of T and B cells compromise the host’s ability to mount
an antigen-specific immune response to opsonize bacteria for phagocytosis.

Symptoms and Treatment

        Research shows that 90% of the disease is associated with complex congenital
heart disease and other malformations in the bodies organ systems. Examples include
autosomal recessive inheritance, severe abdominal pain, vomiting, trouble breathing

         The spleen is very important for the body’s defense against infections. It filters
antigen and antibody complexes and bacteria. The spleen is particularly important in
removing bacteria that are not well opsonized from circulation. As well, it is an important
site for immunoglobulin M production, antigen presentation to T cells and memory B cell
differentiation. The lack of such functions when the spleen is absent or not functioning
properly explains the increased susceptibility to bacterial infections

Because the spleen plays a critical role in the clearance of bacteria from the blood stream
and is also important in antibody synthesis, a patient with asplenia is at significant risk of
serious life-threatening infections and fulminant sepsis, especially in the first 2 years of
life.
A clue to the underlying problems may be obtained by careful examination of
radiographs, which may reveal abnormal placement of the cardiac apex, stomach bubble
and liver. Once Asplenia is diagnosed, aggressive management is the key to decreasing
the amount of deaths. There are 4 key parts to the treatment of this disease: 1. antibiotic
prophylaxis, 2. appropriate immunizations, 3. aggressive management of suspected
infection and 4. parent education

   1. antibiotic prophylaxis is a treatment with a significant amount of antibiotic,
      because the bodies immune system is so weak and very susceptible to infection.
   2. Patients then need to immediately receive all the standard immunizations as well
      as a conjugated H Influenza vaccine. This conjugated vaccine elicits more
      antibody responses than the non-conjugated vaccine.
   3. Aggressive Management means to report to the doctor immediately even if a
      simply cold has occurred. This could lead to further problems if not treated
      immediately with drugs.
   4. Parent Education means to notify the parents as soon as the child has been
      diagnosed so proper action can be taken.

Questions:

   1) What are two important functions of the spleen after birth?

       It plays an active role in the production of IgM antibodies, and it is a
       significant reservoir for T lymphocytes.

   2) The spleen is an important scavenger, which it participates in the destruction of
      what 3 bloodelements?

       Erythrocytes, white cells, and platelets

References:

http://www.emedicine.com/ped/topic150.htm

http://www.acii.net/issues/20002ct.pdf

http://medic.med.uth.tmc.edu/edprog/Immuno/CVignette.htm

								
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