Though hematology and clinical chemistry can provide a lot of valuable information on their own, there are some diagnoses and treatments that require the combination of the two.
For instance, in fever investigations, the hematology analysis provides input regarding the white blood cell count. This can give indications as lymphocytosis, generally associated with viral infections, or neutrophilia commonly caused by bacterial infections. However, these indications can also be caused by other conditions such as stress or certain cancers.
Because the blood system is so complex, the results of a blood cell count need to be considered next to a physical exam and the anamnesis of the patient. To further reinforce the fever investigation and provide clinical data supporting the diagnosis, clinical chemistry can often be of help.
C-reactive protein (CRP ) and serum amyloid-A (SAA ) are two acute phase proteins, that drastically increase as a reaction to an inflammation. Both SAA and CRP can increase more than one hundred-fold in response to a systemic inflammation and both quickly drop when the inflammatory stimulus is eliminated. They are thus valuable biomarkers for inflammation. However, it is important to note that SAA and CRP are markers that might also increase as an unspecific response to immune-mediated diseases, surgical traumas, neoplasias, and similar, and should therefor not be considered alone.
In summary, the WBC differential from a hematology analyzer in combination with CRP or SAA will provide you valuable input for your fever investigation.