From the Guidelines
An abnormal basophil to neutrophil ratio in a CBC is a significant indicator of an underlying hematologic disorder, such as chronic myeloid leukemia, and warrants further diagnostic testing. Normally, basophils make up less than 1% of white blood cells while neutrophils comprise 40-60%, so the B:N ratio is very small. An elevated ratio (increased basophils and/or decreased neutrophils) may suggest allergic reactions, certain inflammatory conditions, or myeloproliferative disorders like chronic myeloid leukemia, as seen in studies such as 1 and 1. Conversely, a decreased ratio (reduced basophils and/or increased neutrophils) often points to acute bacterial infections, stress responses, or corticosteroid use.
Some key points to consider when evaluating an abnormal B:N ratio include:
- The presence of basophilia (>20% basophils in blood) is a criterion for accelerated phase chronic myeloid leukemia, as noted in 1 and 1
- The B:N ratio should never be interpreted in isolation but considered alongside other CBC parameters and clinical symptoms
- Further diagnostic testing is typically needed, which may include bone marrow examination, additional blood tests, or specific allergen testing depending on the suspected underlying condition
- The ratio changes because basophils release histamine and other inflammatory mediators during allergic and parasitic responses, while neutrophils are the primary responders to bacterial infections
In the context of chronic myeloid leukemia, an abnormal B:N ratio can be an important indicator of disease progression, as seen in studies such as 1. Therefore, it is essential to carefully evaluate the B:N ratio in conjunction with other clinical and laboratory findings to determine the underlying cause and guide further management.
From the Research
Basophil to Neutrophil Ratio in CBC
The basophil to neutrophil (B:N) ratio in a Complete Blood Count (CBC) is an indicator of various health conditions.
- An abnormal B:N ratio may indicate an underlying condition that affects the production or function of basophils and neutrophils.
- Basophils are the least abundant cells in blood, and their counting in hematology analyzers is not reliable due to high analytical imprecision and poor specificity 2.
- Neutrophils, on the other hand, are a type of white blood cell that plays a crucial role in the immune system, and their elevated levels have been associated with increased mortality in patients with stable coronary artery disease 3.
- The B:N ratio may be affected by various factors, including infections, malignancies, and hepatic disorders, which can cause neutrophil aggregation and pseudoleukopenia 4.
- A study found that high levels of basophils were associated with enhanced factor II plasma coagulant activity and increased risk of mortality in patients with stable coronary artery disease 3.
- However, there is limited research on the specific interpretation of the B:N ratio in CBC, and more studies are needed to understand its clinical significance 5, 6.