Measuring a patient’s ratio of white blood cell types may help to distinguish between infectious mononucleosis and bacterial tonsillitis, according to a new study.
In the study, doctors at St George’s Hospital in London retrospectively analysed laboratory tests from 120 patients with infectious mononucleosis and 100 patients with bacterial tonsillitis treated at their facility.
All patients were given the spot test for mononucleosis and additional blood tests were performed to determine the number of lymphocytes and overall white blood cell count.
Total white blood cell count was significantly increased in the tonsillitis group compared with the mononucleosis group (16,560 cells per microliter versus 11,400 cells per microlitrer), but the lymphocyte count was higher in the mononucleosis group (6,490 cells per microliter versus 1,590 cells per microliter). The ratio of lymphocyte/white blood cell count ratio averaged .54 in the mononucleosis group and .10 in the tonsillitis group.
Based on this data, the researchers determined that a ratio higher than .35 would have a sensitivity of 90 per cent and a specificity of 100 per cent for the detection of mononucleosis.