Prognostic marker in hematology
β2-microglobulin is present on the surface of all nucleated cells and enters the blood during their renewal and destruction. In multiple myeloma, lymphomas and chronic lymphocytic leukemia, its level is proportional to the mass of tumor cells, therefore the indicator is included in the international myeloma staging system and serves as one of the main prognostic factors. It is also used to monitor the effectiveness of treatment: a decrease in level reflects a decrease in tumor mass. An important limitation is that β2-microglobulin is excreted by the kidneys, and in renal failure its concentration increases regardless of the oncological process, so the result is always assessed together with creatinine.
Why preparation is so important
The laboratory result is a number, but the correct number can only be obtained if the rules are followed. Eating changes the levels of glucose, lipids and a number of enzymes significantly; physical activity the day before increases CK and AST; smoking affects hormones; time of day is critical for cortisol and testosterone.
Therefore, a “bad analysis” often turns out to be a consequence of impaired preparation, and not an illness, and leads to unnecessary examinations and prescriptions.
General rules for donating blood
- on an empty stomach 8–12 hours, you can drink water
- Eliminate alcohol and intense exercise per day
- no smoking in an hour
- donate blood before physiotherapy, x-rays and massage
- Take medications in advance by agreeing with your doctor
- for hormones in women, take into account the day of the cycle
How to read the result
Reference values depend on the method and equipment of the laboratory, so it is correct to compare results only within the same laboratory. A deviation of a few percent from the normal limit in itself rarely matters - the overall picture and dynamics are important. It is up to the physician to interpret the analysis: an isolated indicator without a clinical context is often misleading.