Part 15

The first was a patient, which we were ourselves enabled to investigate by the courtesy of Dr A. Neumann. The patient's spleen was removed by E. Hahn on account of an echinococcus on Feb. 5, 1895. One may well assume that before the operation the spleen no longer discharged its normal function. On Sept. 2, 1897, we found the following numerical proportions:

Polynuclear neutrophil 76.5%, Lymphocytes 18.4%, Eosinophil 3.4%, Large mononuclear 1.1%, Mast cells 0.4%.

A condition therefore which was quite normal. In this connection it must be mentioned that an incipient phthisis pulmonum existed at the time, to which we must attribute an increase of the polynuclear elements, and without which the percentage figures of the lymphocytes and eosinophils would perhaps have been greater.

For the knowledge of the two other cases we are indebted to the kindness of Professor Jounescu of Bucharest. The one case was of a man of about 40 years of age, in whom splenectomy was undertaken on Sept. 27, 1897, for an enlarged spleen. Healing by first intention. The white blood corpuscles were permanently increased. The proportion of white to red was 1:120 to 1:130, the average number of red was 3,000,000. Our own examination of preparations obtained some two months after the operation, shewed a distinct lymphæmia, and also a preponderance of the larger lymph cells. The eosinophil and mast cells were plainly increased. We are unable to give more exact numerical data, as the preparations sent to us were not spread with sufficient regularity.

From the second case, which was also operated upon for enlargement of the spleen, we unfortunately only obtained much damaged preparations. Nevertheless so much could with certainty be established--that there was no considerable increase of the lymphocytes. The eosinophils on the contrary were increased distinctly, the mast cells to a lesser extent. It is probable that the increase of both of the latter kinds of cell was not a consequence of the extirpation of the spleen alone, but rather the expression of the reactive changes, which had already begun before the operation, from the exclusion of the splenic function.

Cases of splenectomy of this kind are transitional to the chronic diseases of the spleen. The latter present great difficulties, for one never knows how far in the most chronic diseases the other organs are damaged or influenced by the general illness.

An increase of the lymphocytes, so long as an affection of the lymphatic glands may be excluded, should be referred to functional exclusion of the spleen.

On the other hand, an increase of eosinophil cells associated with a chronic tumour of the spleen, is analogous to Kurloff's secondary reaction of the bone-marrow. Such cases are frequently found in the literature. For instance Müller and Rieder bring forward three cases of splenic tumour caused by congenital syphilis, cirrhosis of the liver, neoplasm in the cranial cavity, and in which the numbers of the eosinophils amounted to 12.3%, 7.0%, 6.5% respectively. In three cases of acute splenic tumour in typhoid fever the figure 0.31% with a maximum of 0.82%, was found. These authors have already raised the question "whether the increase of the eosinophil cells is connected with the splenic tumour or the bone-marrow? Perhaps the functional activity of the latter is vicariously raised to meet the more or less complete exclusion of the spleen from the formation of the blood; since Ehrlich has distinctly asserted that the probable place of formation of the eosinophil cells is the bone-marrow."

From what has been brought forward no doubt can now remain that the question has been decided quite in Ehrlich's favour.

But what then are the physiological functions of the spleen, since that organ is unnecessary for the persistence of life? Doubtless its chief duty is the taking up of the greater part of the decaying fragments of red and white blood corpuscles in the blood-stream, so that this valuable material is not quite lost for the organism. Thus Ponfick has found that after destruction of the red corpuscles the spleen takes up a portion of their "shadows," and for this reason calls the splenic tumour a spodogenous splenic tumour ([Greek: spodos], ruins). Ehrlich has made a corresponding observation for the products of dissolution of the white blood corpuscles, and has proved that the splenic tumour which occurs in many infectious diseases and in phosphorus poisoning is to a large extent caused by the parenchyma of the spleen taking up the remains of the neutrophil protoplasm.

The question of the relation of the spleen to the =fresh formation of red blood corpuscles= is a problem of comparative anatomy. Observations on this point made on one kind of animal can certainly not claim validity for other kinds. In lower vertebrates, as in fishes, frogs, tortoises, and also in birds, the blood-forming activity of the spleen is pronounced and of great importance. In mammalia on the other hand, in some cases this function cannot be demonstrated, and in others only to a very small degree. In the spleen of normal mice nucleated red blood corpuscles are seen in relatively large numbers; in the rabbit they are less numerous and often only to be found with difficulty. In the dog they only make their appearance after anæmia from loss of blood, normally they are absent. =In the human spleen nucleated red blood corpuscles are not to be found normally or in cases of severe anæmia, but exclusively in leukæmic diseases.= U. Gabbi in his recently published work on the hæmolytic function of the spleen, also emphasises the difference between the various animal species. In guinea-pigs he found that the spleen acts largely as a scavenger of the red blood corpuscles; in rabbits very slightly. Consequently after removal of the spleen in guinea-pigs the number of red blood corpuscles rose 377,000 in the cubic millimetre, and the amount of hæmoglobin 8.2%. After splenectomy in rabbits the increase in these values is absent.

Shortly summarising our analysis of the facts before us, we must say that =the importance of the spleen for the production of the white blood corpuscles can in no respect be considerable=, and that if these cells really are produced by it, they must be free from granulations. The spleen therefore stands functionally in closer connection with the lymphatic gland system than with the bone-marrow. =The spleen has not the least connection with ordinary leucocytosis.=

() The Lymphatic Glands.

As it is impossible experimentally to prevent the lymphatic glands as a whole from contributing to the formation of the blood, we are dependent almost entirely on clinical and anatomical researches for an elucidation of their function.

Since Virchow's definition of the lymphocyte it has been admitted that the lymphocytes of the blood, both the small and larger kinds, are identical with those of the lymphatic glands and the rest of the lymphatic system. This is proved by the complete agreement in general morphological character, in staining properties of the protoplasm and nucleus, and from the absence of granulation.

Abundant clinical experience testifies that the lymphocytes of the blood really do arise from the lymphatic system. Ehrlich had previously observed that when extensive portions of the lymphatic glandular system are put out of action by new growths and similar causes, the number of the lymphocytes may be considerably diminished. These observations have since that time been confirmed by various authors. For example, Reinbach describes several cases of malignant tumour, particularly sarcoma, in which the percentage of lymphocytes, which normally amounts to about 25%, was very considerably lowered; in one case of lymphosarcoma of the neck they only made up 0.6% of the total number. These conditions are quite easily and naturally explained by the exclusion of the lymphatic glands. It is difficult for the advocates of the view that the lymphocytes are the early stages of all white blood corpuscles to reconcile it with these facts. According to their scheme the low number of lymphocytes is to be explained in such cases by their unusually rapid transformation to the polynuclear elements--the old forms; or to appropriate the expression of Uskoff, by a too rapid ageing of the lymphocytes.

Further evidence for the origin of the lymphocytes of the blood from the lymphatic glands is to be obtained from those cases in which we find an increase of the lymphocytes in the blood. These "lymphocytoses" occur, in comparison with other leucocytoses, relatively seldom. Under certain conditions in which a hyperplasia of the lymphatic glandular apparatus makes its appearance, we often see at first an increase of the lymphocytes in the blood. Ehrlich and Karewski in some unpublished work have investigated together a large number of typical cases of lymphoma malignum, and were able constantly to observe a lymphocytosis, which in some cases was of high degree and bore almost a leukæmic character.

Relying on these facts Ehrlich and Wassermann (Dermatolog. Zeitschr. Vol. I., 1894) made the diagnosis in vivo of malignant lymphoma in a rare skin disease, chiefly from the absolute increase of the lymphocytes alone, although no swelling of the glands was palpable. The post-mortem shewed that the chief condition was a swelling of the retro-peritoneal lymph glands to lumps as large as a fist.

The lymphocytosis following extirpation of the spleen also belongs to this category, since a vicarious enlargement of the lymph glands is always to be observed in these cases.

On investigating the conditions under which in healthy individuals an increased number of lymphocytes enter the blood-stream, we have in the first place to notice the digestive canal, whose wall contains a thick layer of lymphatic tissue. According to the results of Rieder the proportion of the lymphocytes to polynuclears is practically normal in the leucocytosis of digestion, indeed the lymphocytes are rather in excess. The eosinophils on the other hand shew a marked relative reduction in this condition. The leucocytosis of digestion consequently differs essentially from the other kinds, in which the neutrophil elements are chiefly increased. The simultaneous increase of lymphocytes and polynuclears is doubtless brought about by a super-position of a raised income of lymphocytes, and an ordinary leucocytosis caused by the assimilated products of metabolism.

The influence of the digestive tract is still more evident in certain diseases, more particularly in intestinal diseases of infants. A considerable increase of the lymphocytes in the blood-stream is here to be observed. Thus Weiss found an important increase of the white blood corpuscles in simple catarrh of the stomach and intestines, which presented the main features of a lymphocytosis.

Whooping-cough, according to the recent observations of Meunier, also belongs to the small number of diseases which are accompanied by a pronounced lymphæmia. In the convulsive period of this disease both the polynuclear cells and the lymphocytes are increased, the latter in preponderating amount. The former cells are increased to twice, the lymph cells to four times their normal amount. Doubtless in these cases also the lymphocytosis is due to the stimulation and swelling of the tracheobronchial glands.

An increase of the lymphocytes from chemical stimuli is exceedingly rare, though, as is well known, a large number of substances (bacterial products, proteins, nucleins, organic extracts, and so forth) can call forth a polynuclear leucocytosis. In quite isolated cases, an increase of the lymphocytes in the blood in consequence of the injection of tuberculin into tuberculous individuals has been seen. (E. Grawitz.) From the rarity of these cases it can scarcely be doubted that here a tuberculous disease of the glands also plays a part, so that the increased immigration of lymphocytes is brought about not by a chemical property of the tuberculin but by the extensive specific reaction of the diseased glands.

Only one single substance has so far been mentioned in the literature as capable in itself of producing a lymphocytosis. Waldstein asserts that he has produced by injection of pilocarpine, a lymphæmia which undergoes a progressive increase with a rise in number of the injections.

The origin also of lymphocytosis is therefore sharply marked off from that of the ordinary leucocytosis, which consists in an increase of the neutrophil elements. Whilst the latter is admittedly the expression of chemiotactic action, and arises by action at a distance of soluble substances on the bone-marrow, lymphocytosis is due to a local stimulation of certain glandular areas. Thus in the leucocytosis of digestion, of intestinal diseases of children, we refer it to the excitation of the lymphatic apparatus of the intestine, in tuberculin lymphæmia we recognise mainly a reaction of the diseased lymph glands. Hence we conclude that a lymphocytosis appears when a raised lymph circulation occurs in a more or less extended area of lymphatic glands, and when, in consequence of the increased flow, more elements are mechanically washed out of the lymph glands. The pilocarpine lymphocytosis does not contradict this view, for pilocarpine causes extraordinary though transient variations in the distribution of water, whereby the inflow into the blood of fluid containing lymph cells is increased. We therefore regard =lymphocytosis= as the result of a =mechanical= process; whilst =leucocytosis= is the expression of =an active chemiotactic reaction= of the polynuclear elements.

This view finds its best support in the fact that the polynuclear leucocytes possess lively amoeboid movement, which is completely wanting in the lymphocytes.

Corresponding to the absence of contractility in the lymphocytes it is also observed that in =inflammatory= processes in contradistinction to the polynuclear neutro-and oxyphils, the lymphocytes are not able to pass through the vessel wall. A very interesting experiment on this point was described by Neumann years ago. Neumann produced suppuration in a patient with lymphatic leukæmia, in whom the blood contained only a very small number of polynuclear cells. Investigation of the pus shewed that it consisted exclusively of polynuclear cells, and that not a single lymphocyte had come into the exudation, although this kind of cell was present so abundantly in the blood.

Histological examination of all fresh inflammatory processes, in which mainly polynuclear elements are found, leads to accordant results. It is well known that small-celled infiltration occurs in the later stage of inflammation, apparently consisting of lymph cells; nevertheless this does not in the least prove that these lymphocytes have emigrated here from the blood vessels. This is not the place to enter into the very extensive controversy on this point. We are content to refer to the most recent very thorough paper of Ribbert. Ribbert regards these foci of small-celled infiltration as the analogues of the lymphatic nodules, and explains their origin by an increase in size of the foci of lymphatic tissue, normally present, though in a condition but little developed.