The Occurrence of Abnormal Leukocytes in the Blood in Acute Infections

During the past year we have had several acute infectious cases, running a febrile course, usually mild and all ending in recovery, but in which the blood picture gave rise to considerable apprehension, at the time, as to the ultimate outcome.The appearance in the blood of cells indistinguishable from those found in acute leukemia, together with enlargement of the lymph nodes and sometimes enlargement of the spleen, with a moderate fever, and absence of definite signs pointing to other disease entity, is a clinical picture that might easily give rise to a grave prognosis.An excessive proportion of lymphocytes, a reversal of the polymorphonuclear lymphocyte relation, is not infrequently seen in the normal blood of children, and occasionally in adults under pathologic conditions other than lymphatic leukemia.A lymphocytosis is also noted in some cases following the administration of certain therapeutic agents.In early childhood is found the most marked increase, due to congenital syphilis, cholera infantum, rickets, scurvy and pertussis.In adult life, hemophilia, cervical adenitis, enlarged tonsils, chlorosis, pellagra, exophthalmic goiter, varicella, mumps, secondary anemia asso- ciated with syphilis, tuberculosis and malaria frequently show an exces- sive percentage of lymphocytes in the blood.This condition is also noted at times following the administration of therapeutic doses of thyroid extract, tuberculin, pilocarpin, and quinin hydrochlorate sub- cutaneously.However, the cases presented in this series have a different aspect and clinical picture from the type of cases noted above.They also present a different picture from that found in acute leukemia, and while each new case may give rise to grave doubts as to prognosis, a careful investigation and study of the history and findings will usually serve to distinguish this type of case from true leukemia.