Since that time a number of confirmatory reports have been brought forward. Ross and Hund have shown that this method has been of value in their hands, and recently a further statement from McGuire and Redden tends to confirm their first views as to the value of immune serum from convalescent patients. Their last report giving a mortality of 6 in 151 cases of pneumonia cannot be other than positive proof of the value of this method of treatment.
As the technical side of the work has been given in several articles, we hardly think it necessary to again review it in detail. A few phases should, however, be recalled. It would seem that either serum or the whole citrated blood may be used. Solis-Cohen and his group of workers believe that whole blood has stronger bactericidal properties than defibrinated blood or the plasma. But yet one cannot complain, even on a theoretical basis, against the results obtained with serum by McGuire and Redden. The use of whole blood increases the detail of the procedure, in that the agglutination reactions must be estimated. Unfavorable results in this regard also naturally cut down the supply of available donors. In a military hospital a dearth of donors does not arise, but in civilian practice the problem is very different. In our work we never gave more than 100 cc. of whole blood; usually the amount varied between 50 cc. and 75 cc. On account of the small amount we felt that isoagglutination would not be a serious factor, and in more than 200 injections we failed to see any evidence of ill results from this source. Giving up to 500 cc., as was done by Ross and Hund, is probably a different affair, and accurate agglutination tests are essential. We feel that if the case is treated sufficiently early in the disease as much good can be shown to occur after 50 cc. as after 100 cc. of blood. We do believe, however, that the pooling of sera, where one is able to carry out this method, as it means a liberal supply of donors, is really the method of choice. Syphilis must be ruled out, both clinically and serologically.
As we emphasized previously, the problem presented in the army hospital and in civilian practice is a little different. We have had some experience with both sides. Fortunately, the greater part of our work was with the Student Army Training Corps, where army conditions were more or less carried out. There was never any difficulty in getting donors. In fact, the idea of giving blood appealed to these young fellows. In civilian life it is, in our experience, a more difficult problem. The usual personnel of the public ward has always its fair percentage of positive Wassermann reactors, and the type of individual is quite different from the young soldier. For a relative or friend we could easily get a donor, but this group would cover only a small percentage of the cases one wished to treat. The technique of giving blood can be reduced to a very simple procedure, and by no means should be regarded as a difficult surgical undertaking. Combining the receiving apparatus of Ross and Hund (J. A. M. A., 72, 1919, p. 642) with the syringe method for giving the blood which we suggested in our previous article makes an ideal arrangement.
The results depend upon the time of treatment. The earlier the pneumonia is recognized the better are the chances of recovery. It is our belief that the majority of influenza cases which kept a fairly high temperature for more than four days had a lung lesion, even if we could not make out definite consolidation. As the convalescent influenza serum may have value only for the influenza infection, it would, therefore, appear but logical that a late pneumonia which almost always has other organisms present would not react as favorably. We have seen very few of the deeply cyanotic type recover even with serum. The essential rule is to treat them before this stage develops.
We have observed little or no change in the leucocyte count, even after successful treatment, and taking our group as a whole we are rather surprised at this result. Other observers have noticed a marked increase in the leucocytes as the case reacted favorably to the injections. We agree with McGuire and Redden that the patients with counts below 10,000, as a rule, show the best results. This possibly indicates that the influenza infection is predominating, and that the usual secondary invaders (pneumococcus and streptococcus) are at this time playing but a little part. Hence the value of early treatment is apparent.
From the published results of different workers and our own experience, we feel that influenza immune serum or whole citrated blood given early in the pneumonia is of undoubted value—in fact, almost specific. If the epidemic reappears next year, unless some other better method is forthcoming, we would advise its more general use, and would suggest the collection of pooled serum as early as possible in the epidemic.
At the end of this article there is appended a series of our ward record charts of patients who developed pneumonia following the influenza. These charts are shown to indicate the results of giving immune convalescent citrated blood in pneumonia. The ones presented are from some of the group which recovered. We have, of course, the charts from the fatal cases, but as they do not bring out any special point, save that there was little or no change after treatment, we are omitting them. It is not our idea, however, to give the impression that we have had nothing but success with this method of treatment. It might be well to emphasize some of the salient points which are brought out.
(1) The regularity of the drop in temperature after the injection is almost generally demonstrated.
(2) The occasional chill following the injection seemed to have no untoward results.
(3) The leucocytes show, as a rule, little or no variation after transfusion. Our work agrees with McGuire and Redden’s statement that the cases with a leucocyte count under 10,000 give the best results with immune serum.