Infectious Lymphocytosis

various changes have been noted in the lymphatic system during infection. The paper by Sprunt and Evans2 in 1920 and the subsequent discovery twelve years later of heterophile antibodies in the serum of patients with infectious mono-nucleosis3 stimulated renewed interest in the problem. Data from most laboratories show that the leucocytes rarely pass a level of 20,000 and that there is an "increase of the mononuclear elements." The finding of an "increase of the mononuclear elements" has probably been responsible for the delay in separating cases of infectious mononucleosis from those considered to fall into the group "infectious lymphocytosis." The mononuclear cells involved in glandular fever are generally accepted to be either young or abnormal lymphocytes. They vary in size; the nuclei may be of different shapes; the cytoplasm is usually deeply basophilic. The Paul-Bunnell test is positive in from fifty to ninety per cent. of patients, depending to a large extent on the cases which the individual author chooses to include as infectious mononucleosis in his series. Carl H. Smith,4 in 1941, separated from infectious mononucleosis a group of cases constituting a new disease entity which he called infectious lymphocytosis. Early in 1941 Reyersbach and Lenert5 reported sixteen cases of "atypical infectious mononeucleosis" which occurred over a period of six months in a convalescent home for children recovering from rheumatic fever. The authors discovered these cases while doing routine blood counts in 108 patients. There was complete absence of physical signs and symptoms. The leucocytes varied from 18,400 to 59,300. The lymphocytes ranged from 71 to 90 per cent. The lymphocytes were all mature and no abnormal forms were seen. Paul-Bunnell tests were negative in all cases. The injection into rabbits of washings from the throats of patients and of plasma of patients did not induce a monocytic response. Cultures from the throat of some of the children did not disclose listerella mono-cytogenes. Another significant paper in the same year by Thelander and Shaw,6 who presented the case reports of two sisters aged 21 and 3j years. The sisters became ill within four days of each other, with symptoms of fever, pain in the back of the neck, convulsions, and twitching of muscles. One of the children had a palpable cervical and shotty inguinal lymph nodes. The highest leucocyte count in the respective cases was 50,500, with 84 per cent. lymphocytes; and 45,700, with 86 per cent. lymphocytes. Heterophile …