Siemens ADVIA 2120, Operator'S Manual, Page: 130 / 477

6-12 Flags
Sample Related System Related
•
CML
•
Bone marrow transplant
•
Chemotherapy
1. Check the RBC reagents.
2. Check the RBC hydraulics.
3. Check the RBC and PLT gains.
4. Check the laser flowcell alignment
Left Shift (LS)
Definition
The presence of nonsegmented neutrophils (bands) is suspected.
The Left Shift flag is triggered if bands obstruct the MN/PMN valley. The flag is
not triggered if %NEUT is less than 30%
For normal samples, the valley separating the MN and PMN populations is well
defined, as determined by its relative depth (d/D). If this valley becomes too
shallow (d/D < 0.15), the MN and PMN populations cannot be separated.
The + LS flag is triggered if BASO d/D is less than 0.15.
The Lobularity Index (LI) is used to set the severity levels for this flag.
The LI is the PMN peak channel number on the Baso X histogram divided by 14,
and it is greater than 1.9 for normal samples. Values lower than 1.9 are usually
indicative of sample abnormality.
In samples where a bimodal distribution is not present, only PMN populations
with PMN peaks greater than channel 20 will be considered as valid PMN
populations. Below channel 20 the software will interpret the peak as a MN
population and the LI value will be blanked. Whenever a PMN peak is identified,
the LI result will be reported.
NOTE
If there is no value for MNx, there is also no value for the Lobularity Index (LI).
1 MN peak channel
2 MN/PMN valley channel
3 PMN peak channel
Default trigger values for the three Left Shift severity levels are:
+ LI > 1.9
++ LI = 1.7 to 1.9
+++ LI < 1.7