April 1, 1940
Dear Dr. Sabin:
It was certainly characteristic of you to telegraph your afterthought with reference to our patient with the presumed megakaryocytic abnormality.  I have experienced the same sensation of afterthought interpretation, based upon things seen but not fully interpreted at the time of the original survey.
I thoroughly concur in your suggestion that one must absolutely rule out other sources for the very abnormal cytoplasmic masses in the blood in this boy.  However, in the survey of the first fixed blood film, sent by mail from Louisville, one of the points which led me to the tentative diagnosis, was that neither granulocytes nor lymphocytes showed any pathologic changes.  This relatively normal condition of the polys, lymphocytes and monocytes, was confirmed in the supravital studies of the blood cells after the patient was admitted to University Hospital, and there was only an exceedingly rare (1/2 to l%) myelocytes present.  Therefore, there was no evidence of disordered maturation and development of granules in the granulocytic series that had intact cells, at any rate, and no persisting basophilia of the cytoplasm with definite granulation, which is usually readily seen in the bloods from patients having a toxic condition affecting the granulocytic cells.
We have stained the peripheral blood each day since the receipt of your wire, and as yet I have not found any of these masses of granular cytoplasm, interpreted as platelets, showing the oxydase reaction.  We are repeating the studies regularly, however, and today we plan to do another sterna marrow aspiration, and I shall apply the oxydase stain to films of marrow cells, to compare with the supravital and Wright's-Giemsa stains.
As you know, Dr. Houghton will culture the narrow material, and I am very eager to see what differences, if any, may become apparent as these possible myelocytoblastic cells grown in contrast with typical myeloblasts and myelocytes from myeloid leukemia.
In the surveys of the marrow tissue the afternoon you mere here, I felt rather definitely that the hyperplasia of blast cells was not typical of myeloblasts, megaloblasts, monoblasts or lymphoblasts.  There did seem to me to be all stages of transition between the large mononuclear cells with nucleoli, and the typical increased number and distribution of characteristic megakaryocytes.
We are doing quantitative studies, with Dr. Wilson's help, on both prothrombin and anti-thrombin content of the blood plasma in this patient, and I am especially interested in seeing whether we can get evidences of abnormal quantity or quality in the thrombin-kinase or anti-thrombin potency of this serum.
Your letter elaborating upon this ease arrived also promptly in due course, and we all appreciated greatly your follow-through and this evidence of the interest which the problem stimulated in your thinking.
The final three days of the seminar I believe went as smoothly and were received as enthusiastically as the first two days.  The men repeatedly mentioned their appreciation of your presence and of your contributions, culminating in a testimonial which was presented to me at the end of the course by Dr. Rudesill of Indianapolis, a copy of which I was asked to forward to you.  I thought this was a very nice, spontaneous gesture from the group, and you will see, from the wording of the appreciation signed by all of the men, that they included all of the individuals active in presenting work to them.
All in all, now that the intensive grind is over, I am glad we made the effort, and I hope you feel as well repaid for the trouble you took, as we do here.
It certainly was like old times to work and lecture shoulder to shoulder with you again, even though it was for but a fleeting few hours, and it has served to re-emphasize both the personal and the scientific privilege which the years in Baltimore and New York gave me as your student and associate.  We are trying to carry on, as you well know,-however far we may miss the goal-, in the tradition of Ludwig to Mall to Sabin, et al.
The children are thoroughly enjoying their books, and have already been asking when Dr. Sabin would come back for another visit.
I hope your trip from here to Denver was pleasant, and that your plans for the day in Chicago carried through without interruption.
I am leaving tomorrow morning at eight o'clock for Cleveland, where, as you know, I have three appearances, but inasmuch as there is only one each day from Wednesday through Friday, it seems, in contrast with the past two weeks, a very light schedule indeed.
After this week I am going to get down both to writing and to the current investigative program, inasmuch as the spring and summer quarters are my lightest teaching and administrative routine period.
All send affectionate greetings, and again deepest appreciation for your visit.
Always most cordially,
Charles A. Doan, M.D.
Professor of Medicine