A 1 year old boy is brought to the OPD by his parents with complaints of inability to gain weight and chronic diarrhoea. He was growing well till the age of 6 months. After that, he staed to develop recurrent episodes of pneumonia. Family history is positive for similar symptoms in a maternal uncle. On examination, he is below the 3rd percentile for weight. Tonsils are absent. Stool is positive for Giardia. Which of the following is not true regarding his condition?
This childs presentation suggests X-linked or Bruton&;s agammaglobulinemia. It is primarily a disease of humoral immunity. Cellmediated immunity is not affected. Bruton Agammaglobulinemia Bruton agammaglobulinemia is an inherited immunodeficiency disease caused by mutations in the gene coding for Bruton tyrosine kinase (BTK). B cells do not differentiate and mature. They are arrested in the pre B cell stage. There&;s extremely low IgG levels (below 100 mg/dL) and absence of other immunoglobulin classes. The tonsils and lymph nodes are usually atrophic. Lymph node biopsy reveals depletion of cells of B cell-dependent areas - The follicles. Babies born with this disorder have viually no peripheral B cells (<1%) and suffer from recurrent bacterial infection Reference: Ananthanarayan and Paniker&;s Textbook of Microbiology Tenth edition
All classes of immunoglobulin levels are reduced
Lymph node biopsy shows depletion of follicles
Both humoral and cell mediated immunity are affected
It is caused by a mutation of the Btk gene
Immunology