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.