Lymphocyte/White blood Cell Count Ratio: Simple Blood Test to Distinguish between Mononucleosis and Tonsillitis

Filed in archive Diagnostics , Studies on January 22, 2007

Acute tonsillitis and infectious mononucleosis are both common ear, nose and throat conditions with similar symptoms: sore throat, fever, painful swallowing, white plaque on the tonsils and redness of the throat and tonsils.

Acute tonsillitis is inflammation of the tonsils caused by bacteria while infectious mononucleosis, characterized by glandular fever, is caused by the Epstein-Barr virus with spontaneous rupture of the spleen and acute intra-abdominal hemorrhage as its potential complications.

At the moment, distinguishing one from the other requires an expensive mononucleosis spot test.

According to an article in the January issue of Archives of Otolaryngology--Head & Neck Surgery (one of the JAMA/Archives journals), measuring a patient's ratio of white blood cell types may help physicians accurately distinguish between the similar conditions.

The study, conducted by Dennis M. Wolf, B.Sc., D.O.-H.N.S., M.R.C.S., and colleagues at St. George's Hospital, London measured the number of lymphocytes (a particular type of white blood cell involved in the body's immune response) and overall white blood cell count: 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 percent and a specificity of 100 percent for the detection of mononucleosis, meaning that an individual with a ratio this high would be correctly diagnosed with mononucleosis 90 percent of the time and an individual with a ratio of .35 or lower would be correctly diagnosed as not having mononucleosis 100 percent of the time.

The study's author concluded:

"The specificity and sensitivity of this test seem to be better than the mononucleosis spot test itself.

In conclusion, we recommend that the lymphocyte--white blood cell count ratio should be used as an indicator to decide whether mononucleosis spot tests are required.

Results from our retrospective pilot study suggest that the lymphocyte--white blood cell count ratio could be a quickly available alternative test for the detection of glandular fever [mononucleosis]."

The blood test (lymphocyte/white blood cell count ratio) can potentially help in making treatment decisions regarding the two conditions.

Source: Science Daily

Article abstract here.