Repeatedly in the course of 3 years, the authors studied the state of cell-mediated immunity (CMI) of 29 patients with precancer (laryngitis chronica) followed on a permanent basis by means of the antigen prepared from the serum of C3H/H2K strain inbred mice infected by the LDH virus. The study was preformed in ENT Clinic of the 3rd Medical Faculty, Charles University, Prague. The immune response to the LDH virus was determined by the leukocyte adherence inhibition test (LAI test) and the evaluation was carried out by average measurements of ad index of positivity (IP). The aim of the study was to evaluate the average index of positivity calculations of patients with laryngeal precancers and its decrease comparing to the group of patients with malignant tumors of the head and neck according to mean IP values the control group (voluntary blood donors). Authors also studied variability of IP values of patients with diagnosed laryngeal precancer during the time of the study. IP values of patients with precancer of the head and neck (laryngitis chronica) differed from those obtained from control group and from patients with diagnosed cancer. The IP values decrease within one year in case of successful treatment, but individual consideration of each precancer case is required.

Keywords: LDH virus, Diagnosis, Laryngeal carcinoma