At times a considerable increase in the number of eosinophile cells is found in films made from persons suffering from lead poisoning, particularly when there has been prolonged obstinate constipation. The count is never high, and is rarely more than 5 or 6 per cent. It is not usual to find any of the other forms of white cells in the blood, and in this way the anæmia of lead poisoning may be easily differentiated from the other forms, such as pernicious anæmia, lymphatic leucæmia, spleno-medullary lymphocythæmia. By examining a number of blood-films derived from persons subjected to lead absorption, and shuffled with a number of films from normal persons, one of us (K. W. G.) has been able to separate out, by the above method, the blood-films taken from the suspected persons. The criteria in the determination were—
1. The presence of basophile granules.
2. Total basophile staining and size of corpuscles—poikilocytosis.
3. Differential count, showing increase in a number of lymphocytes and large mononuclear cells.
Determination of the presence of lead poisoning from the examination of the blood, therefore, receives considerable support; but at the same time it is open to some objection from the fact that it is not in lead poisoning alone that basophile granules make their appearance in the blood. Any cause producing destruction of the red blood-cells, and even their depletion by prolonged hæmorrhage, is followed by an increase in the output of the red cells from the bone-marrow[9]. During this output of extra blood-cells from the bone-marrow, numerous cells gain entrance to the blood, in which the nuclei are not entirely degenerated; and it is these particular cells which give the phenomena of basophile staining, and their presence is rather indicative of the increased blood-formation that is progressing, following blood-destruction, rather than direct evidence of blood-destruction itself.
In a number of forms of anæmia—in fact, in almost all forms of severe secondary anæmia, and certainly all forms of anæmia associated with hæmolysis—the presence of basophile granules may be demonstrated. They are commonly found in pernicious anæmia, secondary septic anæmia, and the anæmia of malaria. Practically, the use of basophile granules in the presence of the blood of lead-workers is being utilized in Leipzig for the early detection of lead poisoning. By means of the Zeiss eyepiece enumeration disc the relative number of basophile granule cells to normal red cells is determined; and when the number of red cells containing basophile granules exceeds 100 per million red cells, the individual from whom the blood is derived is regarded as in a presaturnine condition, and given proper treatment. By this means it has been found possible to diminish the number of persons actually suffering from lead poisoning.
The adoption of such a method has some drawbacks, especially in view of the fact that substances other than lead may cause the basophilia. At the same time there is no doubt that, if all persons employed in lead trades who showed basophilia were suspended from their employment at the present time, a very large number of persons would be dealt with. Yet the practical application of this method is by no means impossible under industrial conditions, and would at any rate give a definite test upon which diagnosis could be made, though it would be quite impossible to expect the general practitioner or the certifying surgeon to estimate the basophilic content. All such estimations would necessarily have to be performed at some properly equipped pathological laboratory, such as at the present time many municipal authorities possess.
These facts are of importance, as a differential count of the white cells, together with a careful inspection of a blood-film for basophile staining and alteration in the red cells, as well as other phenomena noted, together with an estimation of the hæmoglobin contained in the blood, are to our mind of considerably more value in the diagnosis of lead poisoning than is the quantitative estimation of the red or white cells. The following tables give a certain number of enumerations, etc., made from the blood of lead-poisoned persons:
BLOOD-EXAMINATION OF LEAD ANÆMIA—DIFFERENTIAL COUNT PER CENT.
| No. | Hb. | R.B.C. | W.B.C. | Index. | A. | B. | C. | D. | E. | F. | G. | H. | I. | J. | K. | Work. | Notes. |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Per Cent. | |||||||||||||||||
| 1 | 60 | 3,460,000 | 7,000 | 0·7 | 63 | 20 | 6 | 3 | 8 | 0 | + | - | + | - | + | Paint mill | 5 years. |
| 2 | 45 | 1,707,000 | 9,000 | 1·4 | 46 | 38 | 8 | 1 | 7 | 0 | + | + | + | + | + | Paint mill | 10 years. |
| 3 | 55 | 2,620,000 | 20,000 | 1·0 | 58 | 32 | 4 | 2 | 4 | 0 | + | - | + | - | + | Paint mill | 7 years. |
| 4 | 60 | 1,334,000 | 10,000 | 3·0 | 55 | 35 | 8 | 0 | 5 | 0 | + | - | + | + | + | Packer white lead | 5 years. |
| 5 | 54 | 3,210,000 | 8,000 | 0·9 | 52 | 41 | 4 | 2 | 1 | 0 | + | + | + | - | + | Grinder | 6 years. |
| 6 | 60 | 1,347,000 | 10,000 | 3·0 | 59 | 32 | 3 | 2 | 3 | 1 | + | + | + | + | + | White lead | 8 years. |
| 7 | 65 | 3,760,000 | 9,000 | 0·9 | Press and stoves | 8 years. | |||||||||||
| 8 | 65 | 2,200,000 | 10,000 | 0·7 | + | + | Zinc distillation still | 20 years; double wrist-drop 2 years. | |||||||||
| 9 | 50 | 3,860,000 | 8,000 | 0·6 | - | + | + | White lead beds | 10 years. | ||||||||
| 10 | 60 | 3,420,000 | 9,000 | 1·0 | 76 | 16 | 13 | 3 | 0 | 0 | + | + | Packer |