Part 20

In many other diseases as well, the observation has been made that hyperleucocytosis as a rule is only absent in specially severe, or in some way atypical cases. Several observers (Löwy and Richter, M. Hahn, Jacob), have been able to demonstrate experimentally for various infections, that artificial hyperleucocytosis influences the course of an artificial infection most favourably. The question, in what way does this process contribute to the protection of the body, is at the present time under discussion, and introduces the most difficult problems of biology.

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The ~morphological character of leucocytosis~ is certainly not simple, and we must sharply separate various groups, according to the kind of leucocyte increased.

The most important consideration is, whether cells capable of spontaneous movement, and of active emigration into the blood, are increased ("~active leucocytosis~"); or whether the number of those cells is raised, to which an independent mobility cannot be ascribed, which therefore are only passively washed into the blood-stream by mechanical forces ("~passive leucocytosis~").

The passive form of =leucocytosis= corresponds to the different kinds of lymphæmia, including that of leukæmia. In the section on the lymphatic glands, we have established this view in detail, and we have particularly insisted that a suppuration, consisting of lymph cells, does not occur.

In sharp contrast to this form there are for every specific kind of active leucocytosis, analogous products of inflammation (pus, exudations), composed of the same kind of cell.

We divide =active leucocytosis= into the following groups:

([alpha]) =polynuclear leucocytoses=:

1. =polynuclear neutrophil leucocytosis=, 2. =polynuclear eosinophil leucocytosis=;

() =mixed leucocytoses= in which the granulated mononuclear elements take part; "=myelæmia=."

Virchow, the discoverer of leucocytosis, advocated the view, that it resulted from an increased stimulation of the lymph glands. The stimulation of the lymph glands consists in "that they are engaged in an increased formation of cells, that their follicles enlarge, and after a time contain many more cells than before." The swelling of the lymphatic glands has as a consequence an increase of the lymph corpuscles in the lymph, and through this an increase again of the colourless blood corpuscles.

This standpoint had to be abandoned, when Ehrlich shewed that it is chiefly the emigration of the polynuclear neutrophil cells, which brings about leucocytosis. Exact figures on this point were first given by Einhorn, who worked under Ehrlich, and were later generally confirmed. Corresponding with the increase of neutrophil blood corpuscles alone, there is always a relative decrease of lymphocytes, often to 2% and even lower. It must here be borne in mind, that the percentage of the lymph cells may be much diminished, without change in their absolute number. It has however been conclusively demonstrated that occasionally in polynuclear leucocytosis, the absolute number of the lymphocytes may decrease. Einhorn had already described a case of this kind, and recently Türk has for the first time established the fact by an abundance of numerical estimations.

The eosinophil cells are as a rule diminished in ordinary polynuclear leucocytosis, as Ehrlich had already mentioned in his first communication. The diminution is often considerable, often indeed absolute.

A few diseases shew, besides the neutrophil leucocytosis, an increase of the eosinophils as well, as we shall describe in detail in the next section.

Polynuclear neutrophil leucocytosis--leucocytosis [Greek: kat' exochên]--may be divided into several groups =according to their clinical occurrence=. We distinguish:

A. =physiological leucocytosis=,

which appears in health as an expression of changes in the physiological state. To this group belongs the leucocytosis of digestion, the leucocytosis from bodily exertion (Schumburg and Zuntz) or from cold baths, and further the leucocytosis of pregnancy.

B. =pathological leucocytosis=.

1. The increase of polynuclear cells occurring in infectious processes, often called inflammatory, after the principle "a potiori fit denominatio." The majority of febrile infectious diseases, pneumonia, erysipelas, diphtheria, septic conditions of the most varied ætiology, parotitis, acute articular rheumatism, etc. are accompanied by a leucocytosis of greater or less extent. In this connection uncomplicated typhoid fever and measles occupy a peculiar position. In them the absolute number of white blood corpuscles is diminished, and chiefly at the expense of the polynuclear neutrophil cells.

For the details we have quoted, and for the course and variations of leucocytosis in infectious diseases we refer to the thorough monograph of Türk. Of Türk's observations we will mention only that in the final stage of the process of leucocytosis, which occurs at the time of the crisis in diseases which run their course critically, mononuclear neutrophil cells and stimulation forms as well often make their appearance in the blood. In still later stages, in which the blood has once more a nearly normal composition, a moderate increase of the eosinophils--gradually waxing and again waning--is very frequently found (Zappert and others). Stiénon, who has likewise devoted special researches to the occurrence of leucocytosis in infectious diseases, shews this point very well in his curves.

2. =Toxic leucocytosis= occurring in intoxications with the so-called blood poisons. This important group has not yet received adequate treatment in the literature. In general the majority of blood poisons, potassium chlorate, the derivatives of phenyl hydrazin, pyrodin, phenacetin call forth even in man a considerable increase of the leucocytes besides the destruction of the red blood corpuscles. This has been observed experimentally by Rieder.

We observed marked increase of the white blood corpuscles after poisoning from arsenurietted hydrogen, from potassium chlorate, further in a fatally ending case of hæmoglobinuria (sulphonal poisoning?) as well as after protracted chloroform narcosis.

3. The =leucocytosis= which accompanies acute and chronic anæmic conditions, especially posthæmorrhagic.

4. =Cachectic leucocytosis= in malignant tumours, phthisis, etc.

To enter here more precisely into the special clinical importance of blood investigation in different forms of disease would lead us too far, and we refer for this subject to the excellent and thorough monograph on leucocytosis by Rieder and to the papers of Zappert and Türk. In this place we will only touch on the most weighty points.

. The prognostic importance of the enumeration of the white blood corpuscles. Thus for example the absence of leucocytosis influences the prognosis of pneumonia unfavourably (Kikodse and others); and the appearance of numerous myelocytes in diphtheria is ominous, as demonstrated by C. S. Engel (see page 78).

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Finally, we may dismiss in a few words the origin of ~polynuclear neutrophil leucocytosis~, and refer to what has been said in another place on the function of the bone-marrow.