Clinical and laboratory findings in primary generalized and multiple-myeloma-related amyloidosis.

Thirty-four patients with primary generalized amyloidosis (PGA) and 14 with multiple-myeloma-related amyloidosis (MRA) were studied. The commonest clinical manifestations in PGA were nephrotic syndrome, hepatomegaly and congestive heart failure, and in MRA, low back pain, plasmacytoma and rheumatoid-arthritis-like syndrome. Eight patients with PGA had limited clinical expression of the disease, such as involvement of only kidneys, joints, parotid glands or gastrointestinal tract; in one patient amyloidosis was limited to lymph nodes. Low serum concentrations of total protein and albumin were common. M components were detected in the serum of 91% of patients with PGA and 92% of patients with MRA: 70% of the M components in PGA and 25% of those in MRA had lambda light chains. Bence Jones proteinemia was detected in 56% of the patients with PGA and in 77% of those with MRA. The serum concentration of immunoglobulins was decreased substantially in more than two thirds of the patients with PGA. Proteinuria (greater than 250 mg/24 h) was observed in 78% of patients with PGA and in 93% of patients with MRA. Bence Jones proteinuria was noted in 75 and 77% of patients, respectively. Plasmacytic infiltration of the bone marrow was found in 90% of the patients with PGA. The mean survival time of the patients with PGA was 28 months and of those with MRA, 29 months from the time of diagnosis.