The study of immune system state, substance P, hemostasis and interrelation between these systems in respiratory diseases in frequently ill children

Aim. To study immune system state, hemostasis system, the neuropeptide level (substance P) and their interrelation in respiratory diseases in frequently ill children.

Methods. 340 frequently ill children, 125 rarely ill children and 30 apparently healthy children aged 6 months to 6 years were studied in the acute period of the disease, and in the period of clinical remission. Diagnosis was made on the basis of medical history, clinical signs, instrumental and laboratory assessment results. CD3+, CD4+, CD8+, CD19+ lymphocytes count, serum immunoglobulin classes A, G, M, E levels, interleukin-1β, -2, -6, -8, tumor necrosis factor α, substance P were determined.

Results. Strong negative correlation was revealed between the CD4+-cells level, interleukin-2, interferon γ and hemostasis system parameters. Substance P, interacting mainly with interleukin-1β and -2, CD4+-cells, interferon γ, indirectly interacts with the hemostasis system. In recurrent obstructive bronchitis and complicated acute pneumonia course substance P content increase was higher (4.6-fold compared with healthy children). The fact that the immune system indicators, including cytokine status, substance P and hemostasis system do not normalize during respiratory disease clinical remission in frequently ill children indicates the infection persistence, the inflammatory process continuation during clinical remission.

Conclusion. Along with the immune system, the nervous system and hemostasis system play an important role in respiratory diseases severity in frequently ill children, their complications, prolonged duration, recurrence and transition into a chronic condition.