Leukocyte Sedimentation

LEUKOCYTE SEDIMENTATION represents a phenomenon analogous to the sedimentation of erythrocytes; even during the standard performance of the erythrocyte sedimentation reaction with citrate plasma, one can see above the upper boundary of the settled erythrocytes in various cases either a dense, well-separated narrow white layer (consisting under a microscope predominantly of leukocytes), or a more delicate, grayish film, or finally, the entire layer of plasma appears homogeneously turbid. Schilling studied leukocyte sedimentation in more detail in citrate blood in narrow tubes with a special device for observation under a low-power microscope system [later, a special Schilling-Schultz-Kunin apparatus was constructed]. Based on the character of the leukocyte suspension under a microscope, Schilling distinguishes 4 degrees of leukocyte sedimentation: 1) normally isolated, suspended leukocytes—a normal phenomenon; 2) separate clumps of leukocytes—insignificant sedimentation; 3) clear clumps of leukocytes—accelerated leukocyte sedimentation; 4) very large clumps—strong acceleration of leukocyte sedimentation. Determining the rate of leukocyte sedimentation by the size of the transparent plasma zone is only possible late—2–4 hours after the sedimentation of the main mass of erythrocytes—or is generally impossible in normal conditions. Bauer proceeds differently: he mixes defibrinated blood with 2% acetic acid, centrifuges it, repeatedly washes the leukocyte sediment with a physiological solution, shakes the sediment in a physiological solution for 2–3 minutes, and leaves the leukocyte suspension to settle in wide tubes; after 2–4 hours, a strip of transparent solution is noted in mm. The larger it is, the faster the leukocyte sedimentation. Leukocyte sedimentation is accelerated in infectious processes; leukocyte sedimentation is not parallel to erythrocyte sedimentation, in particular, it is not accelerated in blood diseases and cachexias. Leukocyte sedimentation is of significance for the prognosis of infections and for the discovery of infectious foci; however, in all these cases, changes in the hemogram are more sensitive. Leukocyte sedimentation depends on the degree of agglutinability of leukocytes, does not depend on their number, and does not depend on the ratio of blood protein fractions, but rather on some special substances (Schilling). According to data from the Obukh Institute (Bauer, Zaichenko), the acceleration of leukocyte sedimentation completely coincides with the toxicity of leukocytes, determined by the E. Freifeld method; Schultz and Barta note such a coincidence only in ¹/₃ of cases.