Random locomotion in dark-field microscopy of single granulocytes from venous blood, tissue and exudate. Methodological considerations and clinical applications

The random locomotion of granulocytes was studied in dark-field microscopy, and a standardized procedure for the classification of granulocytes into rapid-moving, (RM), slow-moving (SM) and non-moving (NM) cells was developed. When granulocytes from blood donors were tested, 54% were RM, 21% SM and 25% NM with variation between repeated tests, acceptable for a semiquantitative method. When the test was applied in 124 patients with infectious and inflammatory diseases and hematological malignancies, a significantly higher number of NM blood cells was found in patients with septicemia and pneumonia. The method was found especially suitable for samples containing few granulocytes, such as samples from soft-tissue infections, pulmonary infiltrates and neutropenic blood.