Proposed Solutions for a Multiple Myeloma Case with Unobtainable Serum.

Abstract

Background: Multiple myeloma (MM) is a plasma cell malignancy characterized by monoclonal protein secretion. Excessive immunoglobulin production increases blood viscosity, impairing serum separation and complicating laboratory analyses. We present a case of a 54-year-old male MM patient with hyperviscous samples, describing the laboratory solutions applied.

Methods: To extract a sufficient liquid compartment from the initial sample, several approaches were planned: repeated or extended centrifugation using serum separator tubes (SST), collection in heparinized tubes, use of plain tubes with dilution at 1/2 and 1/4 ratios, and mechanical separator tube (MST) usage.

Results: Repeated or prolonged centrifugation in SSTs did not produce sufficient serum. Blood collected in a hep-arinized tube also failed to yield adequate plasma. Sampling into a plain tube with dilution enabled sufficient serum collection, and MST provided the required plasma volume. MST test results were consistent with the patient's clinical status, whereas increasing the dilution ratio in plain tubes led to greater percentage differences compared with MST results.

Conclusions: MST provided optimal and clinically reliable results. If MST is unavailable, we recommend diluting hyperviscous samples in plain tubes, beginning with a 1/2 ratio.