tommyk
04-08-2006, 10:21 PM
Hy 2105
A 9-month-old boy named Mike Tyson, is taken to the emergency room because of high fever.
Breath sounds are diminished in the lungs, and a chest x-ray film shows lobar pneumonia.
Probable streptococcal pneumonia is demonstrated in Gram's stain of sputum and then later confirmed by culture. The child responds to antibiotic therapy. A detailed history is taken during the admission, which reveals that this is the third episode of pneumonia in this young child; the two previous episodes occurred at 6 and 71/2 months of age.
One of the mother's brothers had died of infection at age 9. Immunoglobulin studies demonstrate the following:
IgG
80 mg/dL
[normal 723-1685 mg/dL]
IgA
60 mg/dL
[normal 81-463 mg/dL]
IgM
20 mg/dL
[normal 48-271 mg/dL]
Studies of the lymphocyte population demonstrate normal numbers of T cells and markedly decreased B cells. Which of the following is the most likely diagnosis? (Hint: look at immunoglobins titer)
1-Bruton agammaglobulinemia
2-Common variable immunodeficiency
3-DiGeorge syndrome
4-Transient hypogammaglobulinemia of infancy
5-Wiskott-Aldrich syndrome
a) This is Bruton agammaglobulinemia (X-linked agammaglobulinemia). It causes low or absent numbers of B cells, leading to a panhypogammaglobulinemia. Cellular immunity is intact. The patients typically develop infections after about six months of age, when maternal antibodies have decreased to low levels. There is a life-long predisposition for recurrent pyogenic infections, particularly of the lungs, sinuses, and bones. While the condition is classically considered X-linked, this can only be proven in about 20% of cases. These patients require life-long immunoglobulin therapy and aggressive antibiotic management when infections do develop.
Common variable immunodeficiency can have some clinical overlap with Bruton's agammaglobulinemia, but is characterized by normal B cell levels and typically presents in the second or third decade of life.
DiGeorge syndrome typically presents with hypocalcemia in infancy.
Transient hypogammaglobulinemia of infancy has clinical overlap with Bruton's agammaglobulinemia, but can be distinguished by the presence of normal B cell numbers.
Wiskott-Aldrich syndrome is an X-linked disorder with eczema, thrombocytopenia, and recurrent infection
YOU WILL SEE THIS ON YOUR EXAM
A 9-month-old boy named Mike Tyson, is taken to the emergency room because of high fever.
Breath sounds are diminished in the lungs, and a chest x-ray film shows lobar pneumonia.
Probable streptococcal pneumonia is demonstrated in Gram's stain of sputum and then later confirmed by culture. The child responds to antibiotic therapy. A detailed history is taken during the admission, which reveals that this is the third episode of pneumonia in this young child; the two previous episodes occurred at 6 and 71/2 months of age.
One of the mother's brothers had died of infection at age 9. Immunoglobulin studies demonstrate the following:
IgG
80 mg/dL
[normal 723-1685 mg/dL]
IgA
60 mg/dL
[normal 81-463 mg/dL]
IgM
20 mg/dL
[normal 48-271 mg/dL]
Studies of the lymphocyte population demonstrate normal numbers of T cells and markedly decreased B cells. Which of the following is the most likely diagnosis? (Hint: look at immunoglobins titer)
1-Bruton agammaglobulinemia
2-Common variable immunodeficiency
3-DiGeorge syndrome
4-Transient hypogammaglobulinemia of infancy
5-Wiskott-Aldrich syndrome
a) This is Bruton agammaglobulinemia (X-linked agammaglobulinemia). It causes low or absent numbers of B cells, leading to a panhypogammaglobulinemia. Cellular immunity is intact. The patients typically develop infections after about six months of age, when maternal antibodies have decreased to low levels. There is a life-long predisposition for recurrent pyogenic infections, particularly of the lungs, sinuses, and bones. While the condition is classically considered X-linked, this can only be proven in about 20% of cases. These patients require life-long immunoglobulin therapy and aggressive antibiotic management when infections do develop.
Common variable immunodeficiency can have some clinical overlap with Bruton's agammaglobulinemia, but is characterized by normal B cell levels and typically presents in the second or third decade of life.
DiGeorge syndrome typically presents with hypocalcemia in infancy.
Transient hypogammaglobulinemia of infancy has clinical overlap with Bruton's agammaglobulinemia, but can be distinguished by the presence of normal B cell numbers.
Wiskott-Aldrich syndrome is an X-linked disorder with eczema, thrombocytopenia, and recurrent infection
YOU WILL SEE THIS ON YOUR EXAM