In reference to "use of the lymphocyte count as a diagnostic screen in adults with suspected Epstein-Barr virus infectious mononucleosis".

We read the recent article by Biggs et al. on the use of the absolute lymphocyte count in the diagnosis of infectious mononucleosis. We carried out a similar study on the use of the lymphocyte to white cell ratio, and later reanalyzed our data using an absolute lymphocyte count above 4, in response to an earlier study carried out by Biggs et al. We would like to highlight the divergence in results between our study and the current study by Biggs et al. Biggs et al. analyzed 50 patients with positive monospot tests, and found a negative predictive value of 99%, specificity of 94%, and sensitivity of 84%. Our cohort had 500 positive monospot results, and we found a negative predictive value of 71.7%, a specificity of 96.8%, and sensitivity of 61.8%. Our article demonstrated that a much larger number of patients had positive monospots with a lymphocyte count of <4 (191 cases), suggesting that the use of the lymphocyte count is associated with a high rate of false-negative results. As with the paper by Wolf et al. previously, we recommend the continued use of the Hoagland criteria for diagnosis of infectious mononucleosis, as the modest saving incurred with the abandonment of the monospot test may lead to the provision of misinformation on recovery, including the avoidance of contact sports, and potentially far greater costs to both the patient and the medical institution involved. PAUL LENNON, MRCS JAMES PAUL O’NEILL, FRCSI TADHG O’DWYER, FRCSI Department of Otolaryngology Head and Neck Surgery Mater Misericordiae University Hospital