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Blood product guidelines - possible DiGeorge syndrome

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General notes

DiGeorge Syndrome has many names and versions. Complete DiGeorge Syndrome (DGS) refers to infants with athymia who have a severe immune deficiency. Infants with DGS are at risk of transfusion acquired GVHD (taGVHD) from engraftment of lymphocytes present in transfusion of blood products. Irradiation of blood products ameliorates this risk with destruction of lymphocytes.

DGS with athymia will be present in ~1% of infants with 22q11 deletion. Not all patients with DGS have 22q11 deletion; deletions in chromosome 10, mutations of CHD7, CHARGE, and prenatal exposure to isotretinoin or high glucose have been described as associations.

Table 1: Frequency of common cardiac defects in 22q11

  Frequency of Finding
Cardiac anomalies
Tetralogy of Fallot
Interrupted aortic arch
Ventriculoseptal defect
Truncus arteriosus
49-83%
17-22%
14-15%
13-14%
7-9%

 Table 2: Frequency of the chromosome 22q11.2 deletion associated with the following cardiac anomalies

  Frequency of Deletion
Any cardiac lesion
Conotruncal cardiac anomaly
Interrupted aortic arch
Pulmonary atresia
Aberrant subclavian
Tetralogy of Fallot
Velopharyngeal insufficiency
Velopharyngeal insufficiency post adenoidectomy
Neonatal hypocalcaemia
Schizophrenia
1%
7-50%
50-60%
33-45%
25%
11-17%
64%
37%
74%
0 - 6%

From: Kobrynski, Lancet 2007

Of patients with athymia about 80% will have hypocalcaemia / hypoparathyroidism.

Investigation

Infants who have 22q11 deletion or other features suggesting DGS are at risk of taGVHD. Investigations should be undertaken as soon as possible and should include:

  • Review of CXR for thymic shadow
  • Blood count
  • Lymphocyte phenotype
  • Lymphocyte proliferation to PHA

Transfusion management

An urgent decision will often be needed where an infant at risk needs cardiac surgery.

  • If these results are not available prior to surgery then irradiated blood should be used.
  • If the results are available prior to surgery:
    • Infants with low T cells counts (eg CD4<400/ul) should have an immunology consult for further investigation, and irradiated blood should be used.
    • Infants with CD4 counts of >400/ul do not need any precautions for blood transfusion.
      The exception to this is infants who may have "atypical DiGeorge". These infants clinically present with eczematous like rash, adenopathy, and hepatosplenomegaly, due to clonal proliferation of a few T cells. Infants who present with these manifestations and congenital cardiac disease require immunology referral regardless of initial screening tests. If such infants require surgery blood products should be irradiated, even if CD4 count >400/ul.
  • In addition if thymic tissue is present at surgery then no further investigation or particular management of transfusion is required.

Older children with 22q11 or other features of DiGeorge Syndrome may not necessarily need the same precautions. If there is uncertainty about immune status this should be discussed with paediatric immunology.

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Document Control

  • Date last published: 22 November 2012
  • Document type: Clinical Guideline
  • Services responsible: Paediatric Intensive Care Unit
  • Owner: Fiona Miles
  • Editor: John Beca
  • Review frequency: 2 years