Bill was healthy for the first 10 months of his life. In the next year he had pneumonia once, several ear infections, and a streptococcal infection of the skin. These were all treated successfully with antibiotics, but it seemed to his mother he was always on some type of antibiotic. He was a bright and active child who developed normally but he continued to have repeated infections of the ears and sinuses and twice more had pneumonia. At 2 years old his pediatrician tested his serum immunoglobulins and found 80mg/dl IgG (normal is 600-1500mg/dl); no IgA (normal is 50-125 mg/dl), and only 10mg/dl IgM (normal is 75-150mg/dl). Bill was started on monthly intramuscular injections of gamma globulin; his serum level was maintained at 200mg/dl. He did well in school despite numerous absences with recurrent pneumonia and other infections. At age 9 he was hospitalized for partial lung collapse and a chronic cough. On physical examination he was found to be well-developed and alert with normal height and weight, although the doctor noted that he had no visible tonsils. Lab tests showed that his WBC was normal. Flow cytometry was performed on the cells to determine the types of lymphocytes that were present: 85% were determined to be T-cells, but none displayed the marker for a B-cell (normal is 12%). T-cell proliferation indices were normal. Serum IgG remained low and serum IgA and IgM were undetectable. He was given intravenous gamma globulin to maintain his IgG levels at 600mg/dl by infusing himself with 20g of gamma globulin every weekend. He improved remarkably but still has occasional bouts of sinus infections which respond well to antibiotic treatment.
Billâs recurrent infections were almost all due to Streptococcus and Haemophilis species. These bacteria have a slimy capsule composed of polysaccharide polymers that do not respond well to phagocytosis alone. How might the body normally remove this type of infection?
What other genetic defect of the immune system (other than lack of IgG) could mimic this type of disorder?
Bill was healthy for the first 10 months of his life. In the next year he had pneumonia once, several ear infections, and a streptococcal infection of the skin. These were all treated successfully with antibiotics, but it seemed to his mother he was always on some type of antibiotic. He was a bright and active child who developed normally but he continued to have repeated infections of the ears and sinuses and twice more had pneumonia. At 2 years old his pediatrician tested his serum immunoglobulins and found 80mg/dl IgG (normal is 600-1500mg/dl); no IgA (normal is 50-125 mg/dl), and only 10mg/dl IgM (normal is 75-150mg/dl). Bill was started on monthly intramuscular injections of gamma globulin; his serum level was maintained at 200mg/dl. He did well in school despite numerous absences with recurrent pneumonia and other infections. At age 9 he was hospitalized for partial lung collapse and a chronic cough. On physical examination he was found to be well-developed and alert with normal height and weight, although the doctor noted that he had no visible tonsils. Lab tests showed that his WBC was normal. Flow cytometry was performed on the cells to determine the types of lymphocytes that were present: 85% were determined to be T-cells, but none displayed the marker for a B-cell (normal is 12%). T-cell proliferation indices were normal. Serum IgG remained low and serum IgA and IgM were undetectable. He was given intravenous gamma globulin to maintain his IgG levels at 600mg/dl by infusing himself with 20g of gamma globulin every weekend. He improved remarkably but still has occasional bouts of sinus infections which respond well to antibiotic treatment.
Billâs recurrent infections were almost all due to Streptococcus and Haemophilis species. These bacteria have a slimy capsule composed of polysaccharide polymers that do not respond well to phagocytosis alone. How might the body normally remove this type of infection?
What other genetic defect of the immune system (other than lack of IgG) could mimic this type of disorder?
