ERITROTsITOMETRYYa (erythrocytes] + Greek metreo to measure, measure) — size discrimination of erythrocytes.
At E. establish diameter, volume and thickness of erythrocytes. Determination of diameter of erythrocytes can be carried out under a microscope with the help an eyepiece micrometer (see) and automatic (electronic) counters, and also nomograms (see).
The erythrocytometric Price-Jones curve represents graphic registration of distribution of erythrocytes on their diameter. On abscissa axis postpone the size of diameter of erythrocytes in micron, for ordinate axes — percentage of erythrocytes of the corresponding diameter. The received points connect and receive an erythrocytometric curve (fig. 1). Normal the majority of erythrocytes (on average 70%) has diameter of 7 — 8 microns, the maximum is the share of erythrocytes with a diameter of 7,2 — 7,5 microns, to-ry is average diameter and corresponds to top of a curve. Erythrocytes with a diameter less than 6,7 microns belong to microcytes, with a diameter more than 7,7 microns — to macrocytes, with a diameter more than 9,5 microns — to megaloytes. The erythrocytometric Price-Jones curve reflects a condition of an erythrocytopoiesis. Width of the basis of this curve characterizes an anisocytosis. At a macrocytosis and mega-lotsitoze the curve has the flat form, the wide basis, two or several tops and is shifted towards large diameters of erythrocytes to the right, it meets at V12-(foliyevo) scarce anemias. At a microcythemia and a microspherocytosis the erythrocytometric curve has the wide basis, two tops, is shifted towards smaller diameters to the left, meets at micro spherocytic hemolitic and iron deficiency anemias.
The total amount of erythrocytes determined with the help gematokritno-go numbers (see) gives an idea of
Fig. 1. Erythrocytometric Price-Jones curve: and — is normal; — at mik-rotsitarny anemia (the curve has two tops and it is shifted towards smaller diameters of erythrocytes to the left); in — at macrocytic anemia (the curve of a flat form, with several tops, is shifted towards large diameters of erythrocytes to the right).,
a ratio between the volume of plasma and cellular elements of blood. The average volume of an erythrocyte is defined by the attitude of gematokritny number towards quantity of erythrocytes in
1 mkl blood. Normal it fluctuates from 76 to 96 mkm3. The average volume of an erythrocyte increases at a macrocytosis (acute posthemorrhagic anemia, a paroxysmal night haemoglobinuria, diffusion damage of a liver), a macrocytosis and a spherocytosis (enzimopenichesky anemias), a megalotsitoza [In 12-(foliyevo) scarce anemias]. The average volume of an erythrocyte decreases at a microcythemia (e.g., an iron deficiency anemia, a thalassemia, a renal failure). The different volume of erythrocytes (macro - and microforms, sferotsi-you, megaloytes) is observed at hemolitic anemias, leukoses, etc.
During the determination of diameter of an erythrocyte by means of automatic (electronic) counters on the oscillographic screen register an erythrocytometric curve with the subsequent drawing it on paper.
For size discrimination and a form of erythrocytes the holography is used (see). It is based on registration and the subsequent recovery of reflections from an object electromagnetic (optical holography) or sound (acoustic holography) waves.
The average volume and average diameter of an erythrocyte define also by Mazon's nomogram. Basic data are quantity of erythrocytes in 1 mkl blood and gemato-kritny number. On a scale «erythrocytes» and «gematokritny number» find necessary sizes and connect them a straight line. The point of intersection of this line with a scale «the average volume of an erythrocyte» is also an indicator of average volume of an erythrocyte; e.g., at quantity of erythrocytes
of 5 million in 1 mkl blood and gematokritny number of 45% the average volume of an erythrocyte is equal 90 mkm3 (fig. 2). The average volume of an erythrocyte can be determined by a micromethod Panchenko-va, to-ry it is used for definition of ROE (see Sedimentation of erythrocytes). At the same time the size of a column of the besieged erythrocytes is fixed in 12 or 24 hours. The average volume of an erythrocyte is calculated on a formula: Vmkm3 = 100 • where V — the average volume of an erythrocyte, h — height of a column of the besieged erythrocytes, n — number of erythrocytes in 1 mkl blood.
Average diameter of an erythrocyte is calculated on a formula:
Thickness of an erythrocyte is calculated on a formula: T = where V — the average volume of an erythrocyte; S — the area of its basis, edge is calculated on a formula S — yag2 (I am a constant, it is equal to 3,14; — a half of average diameter of an erythrocyte). It is normal
of Fig. 2. Mazon's nomogram for determination of average volume of erythrocytes depending on their quantity (one million in 1 mkl) and gematokritny number (in %).
average thickness of erythrocytes
is 1,9 — 2,1 microns. Increase in thickness of an erythrocyte is noted at a microspherocytosis and a megalotsitoza; reduction — at the planocytosis observed, e.g., in case of a thalassemia.
An indicator of sphericity, or a spherocytic index — the relation of average diameter of an erythrocyte to its average thickness. Normal it fluctuates from 3,4 to 3,9. Values below 3,4 indicate tendency to a spherocytosis, higher than 3,9 — to a planocytosis. Nek-ry researchers give wider borders 2,4 — 4,2.
Bibliogrkassirsky I. A. and Alekseev G. A. Clinical hematology, M., 1970; The Guide to clinical laboratory diagnosis, under the editorship of M. A. Bazarnova, the p. 2, page 24, etc., Kiev, 1982; N. P Falcons. Scoping of erythrocytes in the device Panchenko-va, Klien, medical, t. 32, No. 2, page 71, 1954; The Reference book on clinical laboratory methods of a research, under the editorship of E. A. Kost, M., 1975; Todorov Y. Clinical laboratory trials in pediatrics, the lane with bolg., Sofia, 1968.
V. T. Morozova.