Objective. To reveal additional laboratory criteria for assessing the affection of the nervous system in case of neurosyphilis. Materials and methods. There was a study of 49 patients with a specific affection of the nervous system. The complex study comprised a clinical examination performed by a dermatovenerologist, a neurologist and an ophthalmologist as well as serologic examination of blood and spinal fluid. The level of IL-6, IL-17 and TNF-α in parallel blood and spinal fluid samples was determined. Results. The authors obtained statistically significant results for the concentration of IL-6 and TNF-α. The increased level of these indices was observed in the spinal fluid of patients with the most severe neurological manifestations of the specific process. Thus, it is evident that changes in this index reflect the severity of affection for all components of the nervous tissue. The described changes demonstrate the autoimmune nature of pathological processes taking place in the nervous system.