Immunoglobulins in families of myeloma patients.

The serum immunoglobulin levels of 200 first-degree relatives and 23 spouses of 32 patients with myelomatosis were compared with those of age- and sex-matched control persons. First-degree relatives of myeloma patients appeared to have higher serum levels of IgG (P less than 0.05), IgA (P less than 0.