Serum ferritin and beta 2-microglobulin in patients with multiple myeloma

In 76 patients with clinically well-defined multiple myeloma (median age at diagnosis: 68.5 years), serum ferritin (SF) and beta 2-microglobulin (beta 2M) were measured by RIA methods. Seventy sex- and age-matched healthy individuals served as controls. Both serum ferritin (median: 343 vs 193 micrograms/liter; P less than 10(-7] and beta 2M (median: 4.25 vs 3.5 mg/liter) showed a significant increase (P less than 0.05) in myeloma patients compared to controls. Intercorrelation analysis revealed significant correlations between SF and tumor mass, serum creatinine, and beta 2M, and between beta 2M and tumor mass, percentage of plasma cell infiltration in bone marrow, agglutinine titers, serum creatinine, hemoglobin, and age of the patients. Both tumor proteins might gain clinical importance particularly in those patients in which precise monitoring of disease is impossible either due to lack of paraprotein production or due to the particular paraprotein type. This seems to account for patients with light chain paraproteins, and for those patients with biclonal gammopathies or with IgE and/or IgD paraproteins.