immunlogy case report done by Areen Mitt'b talk about Severe combined immunodeficiency omenn syndrome uploded by Abbas W. Abbas

1. Severe combined immunodeficiency
(SCID): Omenn syndrome
Done by:
Areen Mittib
"The Case of baby J.K" by Areen.A.E Mittib

2. Severe combined immunodeficiency
(Omenn syndrome): case Report
By
Areen.A.E Mittib
Immunology course
Al-najah university-faculty of medicine
Summary:
The case involves an infant who suffers from recurrent infection. He was
diagnosed with severe combined immunodeficiency (SCID) which is a type
of genetic disorder represented by T cell deficiency as well as B cell deficiency.
SCID results from an aberration in the development of different classes of
immune cells receptors due to a defect in the molecular mechanism known
as somatic recombination which RAG enzymes play a critical role in it.
This patient had suffered from bladder infection, recurrent ear infection associated with chronic diarrhea and failure to thrive.
Early recognition of SCID is a pediatric emergency and awareness of this
condition should lead to a more sympathetic management of the case.
Introduction:
SCID (bubble boy disease) is a genetic disease that results when one of the
thirteen genes involved in a molecular mechanism known as somatic recombination is mutated. Somatic recombination is responsible for giving
rise to variable B and T cell receptors. It's classified to many types according to the mutated gene. Omenn syndrome is the type results when RAG
coding gene is mutated (1) (4).
It’s relatively uncommon with a prevalence of approximately 1 in 100,000
births. Babies with SCID, if untreated, usually die within 1 year unless they
have undergone successful Hematopoietic stem cell transplantation or other treatments (1) (4).
Its clinical features are severe microbial infections early in life and often associated with chronic diarrhea and failure to thrive (1) (4).
"The Case of baby J.K" by Areen.A.E Mittib

3. Case History:
At birth, Baby J.K was a normal baby boy. Both of his parents were in
their late twenties and were healthy. At the fourth weak, J.K developed a
middle-ear infection .He suffered from recurrent ear infections over the
next three months, which required antibiotic treatment (3).
His pediatrician recommended taking of the fluid from his ear and Cultures
of the drainage fluid showed the presence of Homophiles influenza (3).
At the third months of age, J.K had four episodes of diarrhea which persisted
for 3–5 days each time. J.K also was not gaining weight as rapidly as was
expected during this time. At the fourth months, he developed another ear infection, this one more severe than the first. His mother mentioned unusual
,unpleasant odor when she changes his diapers .Ear’s fluid specimen was
taken and cultured , the culture revealed the presence of Pseudomonas
aeruginosa and his doctor determined that J.K suffered from bladder infection (3).
No lymph nodes could be palpated in J.K’s neck or axilla. His heart, lungs,
liver, and spleen were of normal size (3).
Diagnosis:
His physicians took a blood sample for a complete blood count (CBC). The
results show normal RBC and platelet number but low WBC number especially T cell and B cell while high number of NK .A sample of J.K’s DNA
was sent for sequence analysis, which revealed mutations in both copies of
his RAG gene (3)(4)(1)
Discussion:
J.K suffered from recurrent ear infection, the first was at age four weeks by
haemophilus influenza and the second was at age four months by Pseudomonas aeruginosa , urine odor indicate that there was bladder infection
. All these infections indicate there is no response by Adaptive immune system for bacterial infection (immunodeficiency).
Complete blood count (CBC) shows normal RBC and platelet number but
low WBC number especially T cell and B cell while high number of NK. B
and T cell failed to mature and undergo apoptosis (negative selection) so
their numbers are low.
"The Case of baby J.K" by Areen.A.E Mittib

4. J.Ks condition diagnosed as severe combined immunodeficiency omenn type
and was confirmed by DNA sequence analysis, which revealed mutations in
both copies of his RAG gene. The mutations in both genes which resulted
in a complete lack of expression of functional RAG protein.
Conclusion:
This Case about infant who suffers from recurrent infection and diagnosed
with severe combined immunodeficiency (SCID) which is a type of genetic
disorder represented by T cell deficiency as well as B cell deficiency.
Omenn syndrome forms due to genetic mutation in gene responsible for
expression of RAG enzymes .RAG enzymes play a critical role in development of T and B receptors by process known as somatic recombination.
complete loss of these enzymes cause inability of T cell and B cell to mature and then by negative selection these cell will die , so the number of
these lymphocyte will decrease.
Treatment:
J.K was received intravenous antibiotics to treat the ear and bladder infections and intravenous fluids. He recovered from the infections but remained
weak.
My own opinion:
NK number in CBC was high. Its number increases as an alternative of T
and B cell because of no somatic recombination mechanism needed for its
receptor formation.
"The Case of baby J.K" by Areen.A.E Mittib

5. I think about Gene therapy or bone marrow transplantation for long term
treatment .But may transplant bone marrow rejects by the large number of
NK.
Appendices:
References:
1-Santagata S, Villa A, Sobacchi C, Cortes P, Vezzoni P (2000). "The genetic and biochemical basis of Omenn syndrome". Immunology Rev. 178: 6474
2- : Parham, Peter. 2005. The Immune System, 2nd Edition. Garland Science, New York, NY.
3- Munoz-Robles, J., M.J. Del Rey, J. Ruiz-Contreras, et al.. Partial Immune Reconstitution after Bone Marrow Transplantation in a Boy with
Recombination Activating Gene 1 Defect. Bone Marrow Transplantation
33(8):877–878
4- Villa, A., C. Sobacchi, L.D. Notaraneglo, et al. V(D)J Recombination Defects in Lymphocytes due to rag Mutations: Severe Immunodeficiency with
a Spectrum of Clinical Presentations. Blood 97(1):81–88.
"The Case of baby J.K" by Areen.A.E Mittib