Inflammatory reaction and laboratory tests: hematologic examination

The leukocyte count, the differential leukocyte count and the erythrocyte sedimentation rate (ESR) are the more commonly used tests for diagnosing or managing an inflammatory process. Measurements of acute-phase proteins has an advantage over that of the leukocyte count and ESR. Especially microscopic examination of peripheral blood smear can be time consuming, but the simple and inexpensive technique is still clinically useful when a high grade bacteremia is likely to be present. Although the results are examiner dependent, it should be reliable in the proper clinical setting. In the guidelines for the selection of laboratory tests for monitoring the acute phase response, published in 1988, the International Committee for Standardization in hematology (ICSH) considered the biohazzard of ESR. Therefore the ESR should not routinely be performed on blood samples from patients who show a positive test for hepatitis virus or human immunodeficiency virus. The subcommittee for laboratory tests in daily care situations in Japan Society of Clinical Pathology published the "Essential Laboratory Tests" in 1989. We conclude that the differential leukocyte counts and the ESR should be used to follow the activity and response to treatment of certain inflammatory disorders when other objective indicators are not available.