What’s the mean of shift to the left
How to calculate , its indication
Neutrophils are of two types segmented neutrophils and banded neutrophils (or bands).
Segmented are called mature neutrophils, and bands are called immature neutrophils.
In case of infection the immature neutrophils are increased in number.
We define bands equal to or more than 10% as bandemia.
The ratio between bands and the total neutrophils is called I/T ratio and calculated by this formula:
I/T = bands / (bands + segmented)
I/T ≥ 0.2 is considered a positive for sepsis.
Also bands ≥ 10 can be considered as a positive for sepsis.
Amazing question ,wait for amazing answer🙂💻🪧📒
_ In any infection settings ,your bone marrow. Which is your first defense in your body start to increase its production in WBCs expressed in neutrophils to the site of infection to fight as much as possible, so these huge amounts of neutrophils doesn’t wait to be mature ,so more neutrophils consumption ,many immature neutrophils are released in response to mainly Bacterial infection.
So when we find that many immature neutrophils ,it mean rapid release of cells which indicates their is an alarm for early acute infection(Sepsis) and inflammation,OK?
Neutrophils in laboratory report by making CBC with diffrential report studying neutrophil patterns are many stages,as illustrated in attached image
From left to right 6 stage from immature neutrophil to mature one as follwing:
➡️Myeloblast➡️promeylocyte➡️Melocyte➡️MetaMelocyte➡️Band neutrophil➡️Segmented .
So,
** Mature neutrophil= segmented appearance
**Immature neutrophil=Bands🪡= stabs=Bandemia
_ So when we say (left shift), its mean we going to left side where 
high number of banded or immature neutrophils which occur in acute infection as sepsis
_ When we say (right shift),it’s mean we going to the right site towards less number of immature neutrophils which occur in improvement from acute infection or can indicate chronic infection&Macrocytic anemia
Calculation I/T ratio= No of immature(bands) / Total No. Of Immature(bands)+Mature(segmented)
Normal value: bands <10%
Total =The maximum acceptable I/T ratio for excluding sepsis in the first 24 hours is 0.16 nearly=0.2%
