Detection of serum antibodies to amino-pyrine or its derivatives by a passive hemagglutination assay method.

An attempt has been made to detect antibodies to aminopyrine or its derivatives ( pyrazolone derivatives) with a passive hemagglutination assay system. Formalinized red blood cells were sensitized by coupling diazotized 4-aminoantipyrine to the surface membrane. With this method, circulating antibodies were detected in a patient with aminopyrine-induced agranulocytosis. Serial determinations revealed that the concentration of antibody increased rapidly after the onset of clinica l manifestations, reaching a maximum in about a week, and thereafter began to fall off gradually. The presence of antibody was found in 32 sera of 75 patient s with a history of skin reaction due to aminopyrine or its analogues and in 15 sera of 62 control subjects having no such history. The highest hemagglutination titer was 1 : 16. Adverse reactions to drugs occur commonly in clinical practice and constitute a problem of considerable importance. Some of these reactions are judged to be allergic in mechanism t) -s). For example, the administration of aminopyrine or its derivatives (pyrazolone derivatives) has been known to induce agranulocytosis or skin reactions4l. Moeschlin and Wagner5l demonstrated that agranulocytosis was elicited in volunteers to whom blood from a patient with aminopyrine-induced agranulocytosis had been given intravenously. They also found a substance in the plasma of the patient at the height of disease which produced in vitro agglutination of homologous and heterologous leukocytes. In addition to this finding, Thierfelder et al.6l succeeded in demonstrating in the serum of a patient suffering from agranulocytosis due to aminopyrine an antibody-like principle able to agglutinate donor leukocytes in the presence of aminopyrine. The detection and quantitative measurement of such fi::j'i: JJI{::, tifr:j'i: {~, fi:~51JlA, li'i!JIIliifl\'t Received for publication October 22, 1968. * Presented in abstract form at the 9th Annual Meeting of the Japanese Society of Clinical Hematology, Nara, October 31, 1967. ** Present Address: Professor, Second Department of Internal Medicine, Nagoya City University Medical School, Nagoya.