Serum Beta-2 Microglobulin Pretreatment Level
Description
Serum Beta-2 Microglobulin is a protein that is found on the surface of many cells and plentiful on the surface of white blood cells. Increased production or destruction of these cells causes Serum β2 (beta-2) Microglobulin level to increase. Elevated Serum β2 (beta-2) Microglobulin level is a prognostic factor for plasma cell myeloma.
The Revised International Staging System (RISS or R-ISS) is now used to stage plasma cell myeloma (9732/3), using several different criteria. The stages are based on the absence or presence of the following related criteria.
* 3931: Serum Beta-2 Microglobulin Pretreatment Level
* 3930: Serum Albumin Pretreatment Level
* 3857: High Risk Cytogenetics
* 3869: LDH Level
Required for Staging: The AJCC Staging System Plasma Cell Myeloma and Plasma Cell Disorders (9732/3 only) and EOD.
* Note: RISS stage is not applicable for the descriptions of plasma multiple myeloma that are listed in the codes 1 and 9 in the SSDI Schema Discriminator 1: Plasma Cell Myeloma Terminology. If you have coded 1 or 9 for this Schema Discriminator, the four data items listed above are BLANK.
The RISS stages are
* Stage I: Serum Beta-2-microglobulin <3.5 mg/L and serum albumin > 3.5 g/dL and no high-risk cytogenetics and Normal LDH
* Stage II: Not R-ISS I or III
* Stage III: Serum Beta-2-microglobulin > 5.5 mg/L and high-risk cytogenetics and/or high LDH
Rationale
Serum Beta-2 Microglobulin Pretreatment Level is a prognostic factor required in AJCC 8th edition, Chapter 82 *Plasma Cell Myeloma and Plasma Cell Disorders*, for staging of plasma cell myeloma. It is a new data item for cases diagnosed 1/1/2018+.
Additional Info
**Source documents:** laboratory tests (blood only),
**Other names include** B2M, Total Beta-2 microglobulin, B2-microglobulin, and B2M
Notes
**Note 1:** **Physician statement**
* Physician statement of Serum Beta-2-Microglobulin Pretreatment Level can be used to code this data item when no other information is available
**Note 2:** **Pretreatment results only**
* Record this data item based on a **blood test** performed at diagnosis (pre-treatment). Use the highest value available.
* Do not use results from a urine test
**Note 3:** **Component of RISS Stage**
* LDH level is part of the Revised International Staging (RISS). Use the cut points listed in the table below regardless of the lab’s reference range.
Coding Guidelines
**1) Code 5** if Schema Discriminator 1: Plasma Cell Myeloma Terminology is coded to 1 or 9
**2) Code 9** when there is no mention of the Serum beta-2-microglobulin
Default
9
Metadata
SSDI
| Code |
Description |
| 0 |
β2-microglobulin < 3.5 mg/L |
| 1 |
β2-microglobulin ≥ 3.5 mg/L < 5.5 mg/L |
| 2 |
β2-microglobulin ≥ 5.5 mg/L |
| 5 |
Schema Discriminator 1: Plasma Cell Myeloma Terminology coded to 1 or 9 |
| 7 |
Test ordered, results not in chart |
| 9 |
Not documented in medical record
Serum Beta-2 Microglobulin Pretreatment Level not assessed or unknown if assessed |
