77 - okt3

[ArchivalUser]

A 3-year-old boy has had numerous bacterial infections, including respiratory infections with Hemophilus influenzae, Streptococcus pneumoniae, and Staphylococcus aureus since infancy. He develops a polyarthritis that clears with immunoglobulin therapy. A lymph node biopsy is performed, and microscopically the germinal centers of his nodes are rudimentary. During the 3rd decade of his life he develops systemic lupus erythematosus. He demonstrates skin test positivity to Candida antigen. Laboratory studies show that his serum IgG is 110 mg/dL. His total WBC count is 7650/microliter with differential count of 65 segs, 4 bands, 22 lymphs, and 9 monos. Which of the following immunologic disorders best explains these findings?

A A deficiency of adenosine deaminase

B Malformation of 3rd and 4th pharyngeal pouches

C Reduction in CD4 lymphocytes

D A defect of NADPH oxidase

E Failure of maturation of B cells into plasma cells

[ArchivalUser]

E?

[ArchivalUser]

Excellent drhimanshu

E) CORRECT. He has features of X-linked agammaglobulinemia of Bruton. In this condition, B-cell maturation stops after the rearrangement of heavy-chain genes, and light chains are not produced. Thus, complete immunoglobulin molecules with both heavy and light chains are not assembled and transported to the cell membrane. The lack of immunoglobulins predisposes the child to recurrent bacterial infections. Since T-cell function remains intact, viral, fungal, and protozoal infections are not common.

[ArchivalUser]

thanx ...actualy i just went through immuno deficiency diseases few days back

[ArchivalUser]

yep Bruton's disease...nice q OKT3...thanks...