Stability: 3 days at 2–8°C; 6 months at –20°C
High cell turnover in myeloma results in raised serum concentrations of b2 microglobulin and renal dysfunction will result in serum retention contributing further to raised concentrations. Measurement of serum b2 microglobulin indirectly reflects tumour mass, growth rate, and renal function, and, not surprisingly therefore, it is the most powerful single prognostic indicator in the management of myelomatosis. Serum concentrations below 4 mg/L at presentation indicate the best prognosis, while concentrations above 20 mg/L represent the worst prognosis. The relationship of serum b2 microglobulin to tumour mass allows this marker to be used in the same way as the serum paraprotein to monitor disease, particularily in the BJ myeloma where a serum paraprotein is absent and urinary BJ quantitation is unreliable.
a -interferon – used in the maintainence therapy of multiple myeloma – can induce a marked increase in serum b2 microglobulin concentrations and this should be taken into consideration when using b2 microglobulin for the assessment of tumour response during a -interferon therapy.
Can be added on to an existing request up to 4 days following sample receiptSpecimen Labelling Procedure