[Serum interleukin-6 in multiple myeloma: I. Relation to selected laboratory indicators of disease]

In a group of 111 patients with multiple myeloma (MM) comprising a group of 34 patients examined when the diagnosis was established and a group of 77 patients evaluated in different stages of the disease, the author examined the relationship between the interleukin-6 serum level (IL-6), assessed by the method of enzyme immunoanalysis and selected laboratory indicators of the disease. Elevated IL-6 values were recorded in 38% of the patients. In neither of the groups significant relations were found between IL-6 and calcium, urea, creatinine levels, the amount and type of monoclonal immunoglobulin, lacticode dehydrogenase, beta 2-microglobulin, ferritin, IL-2 and its soluble receptor in serum and the incidence of myeloma plasmocytes in bone marrow. In the second (but not in the first) group a significant relationship was recorded between IL-6 levels and the red cell sedimentation rate, the Hb value, the CRP level and serum albumin and the value of thymidinekinase in serum of patients with a value beyond the normal range. From the investigation ensues that examination of IL-6 serum levels in MM contributes so far mainly to improvement of the diagnosis and expedient classification of this disease in clinical practice.