Cord Blood Banking Marketing Training Programme

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Cord Blood BankingMarketing Training Programme

• Module 4
• September 13 , 2005

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TodaysTopics

• HLA Typing
• Thalassaemia

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What is HLA typing

• HLA stands for Human Leukocyte Antigen.
• An antigen is a protein present on the cells in
  your body.
• This HLA protein lets your cells recognize
  anything foreign in your body.
• Human Leukocyte Antigens are on your white cells
  (leucocytes)
• HLA typing is the most important way to decide if
  a donor's stem cells will match yours.
• By the way, blood type and HLA type have nothing
  to do with each other.

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Why is HLA typing important ?

• The degree of HLA compatibility between donor and
  recipient will influence the outcome of the
  transplant.
• The function of the immune system is to fight
  against foreign particles that the body sees as
  "non-self", such as bacteria and viruses. This
  can lead to rejection of the transplanted stem
  cells.
• Cells from the donor's immune system which are
  introduced along with the transplanted stem cells
  ("graft") can also recognise HLA mismatches and
  attack vital organs of the recipient's body
  ("host"). This is called graft versus host
  disease (GvHD).
• The more compatible the donor-recipient match,
  the less likely it is that rejection or severe
  GvHD will occur.

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Inheritance of HLA type

• All humans inherit 1/2 of their entire
  genetic make-up, and thus of their HLA-type, from
  their mother and the other 1/2 from their father.
• For each full sibling, a patient has a one
  in four (25) chance of a full match.

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Inheritance of HLA type. 
The differently shaded circles and squares
represent the 4 familial haplotypes M1 and M2
represent the maternal haplotypes, F1 and F2
represent the paternal haplotypes.
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Likelihood of a HLA match

• More siblings better the likelihood of a
  match
• One sibling 25
• Two siblings 44
• Three siblings 58
• Four siblings 68
• Five siblings 76
• Six siblings 82
• Seven siblings 87
• Eight siblings 90
• Nine siblings 92
• Ten siblings 94

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How is HLA typing performed ?

• A blood sample is required to perform HLA
  typing.
• The white cells are isolated from the blood and
  typing is performed by two different methods
•   Serological testing Where the white cells
  are used
• DNA testing Where DNA extracted from the
  white cells is used.
• LifeCell uses the molecular or DNA method which
  is more accurate
•   

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Searching for a matching donor

• An HLA type consists of two main groups
• Class I antigens (HLA-A, -B, -C)
• Class II antigens (HLA-DR, -DQ, -DP). There are
  six HLA antigens considered most important for
  determining compatibility two A antigens, two B
  antigens, and two DR antigens (eg A 3, 32 B 7,
  37 DR 1, 15).
• We inherit a set (or haplotype) of HLA-A, B and
  DR antigens from each parent.
•  

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HLA Test Reporting

• Preliminary tissue typing takes about 2 weeks.
• Further high resolution (more detailed) tissue
  typing performed on the patient and any
  potentially matched donor samples may take
  another 2 to 4 weeks.

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Thalassaemia
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What is Thalassaemia ?

• Thalassaemia consists of a group of inherited
  diseases of the blood.
• About 100,000 babies worldwide are born with
  severe forms of the disease each year.
• Thalassaemia occurs most frequently in people of
  Italian, Greek, Middle Eastern, Southern Asian
  and African ancestry.

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Occurrence in India

• It is estimated that in India there are over
  100,000 cases of Thalassaemia Major
• And nearly 30 million carriers of the
  Thalassaemia trait.
• The disease is more prevalent in certain
  communities like Sindhis, Punjabis, Gujaratis,
  Bengalis, Gaurs and Saraswats.

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What causes Thalassaemia ?

• Thalassaemia is a genetic disorder
• A child cannot develop the disease unless
  both parents carry the Thalassaemia gene.

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Kinds of Thalassaemia

• The two main types are
• alpha and
• beta Thalassaemia,
• Depends on which part of an oxygen- carrying
  protein (called hemoglobin) is lacking in the red
  blood cells.

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What happens in Thalassaemia ?

• Thalassaemia can cause
• Ineffective production of red blood cells,
• Destruction of red blood cells.
• The red blood cells to be smaller than normal
• The amount of hemoglobin in the red blood cells
  to be below normal levels.As a result, people
  with Thalassaemia often have a reduced number of
  red blood cells in the bloodstream, a condition
  called anemia.

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Progeny of Thalassemics

• People with Thalassaemia major can have babies
  only if their partner does not carry any sort of
  Thalassaemia. But all Thalassaemia major's
  patients children will carry Thalassaemia minor.
  If a Thalassaemia majors partner does not
  carry any Thalassaemia gene none of the children
  would have Thalassaemia major.

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Progeny of Thal Traits

• If both parents have thalassaemia minor
• 25 chance of their children having
  Thalassaemia major,
• 50 will have Thalassaemia minor and
• 25 will be normal.
• Each subsequent pregnancy carries the same risk.

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Thalassaemia Trait

• If only one parent passes the gene for
  Thalassaemia on to the child, then the child is
  said to have Thalassaemia trait.
• Normally healthy apart from mild anaemia during
  pregnancy
• Thalassaemia trait will not develop into the
  full-blown disease, and no medical treatment is
  necessary. 

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Beta-Thalassaemia Major

• Multiple lifelong transfusions save lives
• Overload of iron in the bodies of Thalassaemia
  patients
• The deposits eventually can affect the normal
  functioning of the heart, and liver, in addition
  to delaying growth and sexual maturation.
• Other risks associated with chronic blood
  transfusions for Thalassaemia major include
  blood-borne diseases like Hepatitis B and C

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Diagnosis of Thalassaemia

• Diagnosis can be made by a blood test that
  shows anaemia. Certain types of haemoglobin like
  foetal haemoglobin and haemoglobin A2 are raised
  in their blood.
• Hemoglobin Electrophoresis Under Rs 1000

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Prognosis

• Thalassaemia major- If left untreated the life
  span may be restricted to 3-5 years.
• The treatment is long-drawn, expensive (Rs
  5000-10000 per month) and emotionally taxing for
  the family.
• Thalassaemia minor most carriers unaware of
  problem

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Transplants for Thalassaemia

• Bone marrow
• Peripheral Blood
• Cord Blood
• Candidates for transplant
• Children younger than 16 years of age
• No existing evidence of liver scarring or serious
  liver disease.
• A failure rate of 10-30.

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Prevention of Thalassaemia

• Screening of women and if positive for the
  trait, their prospective husbands must be
  screened .
• If both have Thalassaemia minor then prenatal
  testing must be done. Prenatal detection is by
  Amniocentesis or Chorionic villus sampling ,
  performed between 9 and 18 weeks of pregnancy.

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Offering Hope