The correlation between C-reactive protein and toxic granulation of neutrophils in the peripheral blood

During inflammation, the serum concentrations of granulocyte colony stimulating factor (G-CSF), plasma interleukin-6 (IL-6), and C-reactive protein (CRP) increase. A positive correlation between CRP and the percentages of neutrophils exhibiting toxic granulation during inflammation has been demonstrated, and that the fluctuations of CRP and toxic granulation of neutrophils were similar.

We studied whether grading of toxic granulated neutrophils can be used as a surrogate marker for infection or inflammation, and also be an easier method than previously described methods.

We graded 357 consecutive peripheral blood slides from patients on whom a full blood count with differential count and CRP level was performed, according to intensity of toxic granulation in the neutrophil population, according to a newly proposed grading system.

The CRP range was between 1 and 530.3 mg/l. The results confirm the association between a rise in CRP and progressive intensity of toxic granulation in neutrophils in peripheral blood. Kruskal-Wallis equality of populations rank test showed a statistically significant difference between the graded categories (p=0.0001). The Trend test was also statistically significant (p=0.000).

The proposed system can be applied to patients with inflammatory or infectious conditions, where grading of toxic granulation of neutrophils can possibly be used as a surrogate marker to assess infection or inflammation and their response to treatment. It may be of particular use in cases where traditional infectious or inflammatory markers cannot be used, owing to inherent problems associated with the respective conditions.