Agammaglobulinemia, plasma cell dyscrasia, and amyloidosis in a 12-year-old child.

A 12-year-old boy suffered from recurrent respiratory infections, an immune deficiency characterized by the complete absence of IgG, IgA, IgD, and the salivary "secretory component" associated with a plasma cell dyscrasia. Rectal and kidney biopsy specimens showed amyloid deposits. Amyloidosis has been extensively studied by several groups of investigators in patients with plasma cell dyscrasia in general, and in patients with lambda-Bence Jones proteinuria in particular, but the finding of a monocional serum IgM-lambda component in an agammaglobulinemic child with Bence Jones proteinuria and amyloidosis represents a puzzling clinical syndrome. Searching for monoclonal components in patients with amyloidosis, even if they are agammaglobulinemic, is important. We also discuss here the "mixed type" of amyloid deposition and its relation to the recurrent infections and the plasma cell dyscrasia in this patient.