The Control of the Dosage of Antiserum

For many years antipneumococcal serum was administered in relatively small doses at intervals of 8 hours and injections were continued until the fever subsided (1). Such a slow method of giving antiserum necessitated a prolonged period of treatment and patients often succumbed to the pneumonia before they had been given adequate quantities of antibody. The importance of administering large doses of serum early in the course of treatment is now well recognized and has recently been reemphasized by Bullowa (2). It has been suggested that the ideal method of administering antiserum is to give the entire effective therapeutic dose in a single injection. This has been done by certain investigators with apparent success (3), but the method is highly impractical because, for reasons emphasized in a previous report (4) and illustrated by certain of the cases reported in the present study, it is quite impossible to calculate even roughly the effective therapeutic dose of antiserum for any given patient with pneumonia. To give more than the minimum effective dose only wastes serum and increases the cost of treatment. Neither the slow method of giving repeated injections of antiserum at intervals of several hours nor the ultra-rapid method of attempting to administer the entire effective dose in a single injection is theoretically sound. In order to determine the optimum amount of antiserum to be given patients with pneumococcal pneumonia it is necessary to employ some method of controlling the dosage of serum based upon the measurement of type-specific antibody circulating in the patient's blood. Various methods have been advocated in the past, none of which has proved to be entirely satisfactory. The most widely used has been the microscopic agglutination test introduced by Sabin in 1930 (5). Besides minor technical drawbacks which are inherent in any agglutination method (4), the test may, under certain circumstances, be unreliable as a guide to serum therapy. To illustrate this fact the following case report is briefly presented (see Figure 1):