Titanium dioxide stimulates phagocytic activity of blood neutrophils

Aliakhnovich N.S.

Vitebsk State Medical University, Vitebsk, Belarus

The aim. Evaluation of the TiO2 effect on the phagocytic activity of peripheral blood neutrophils.
Materials and methods. 17 people were examined - 10 people with atopic bronchial asthma (m/f - 5/5, mean age - 38 [28, 48]), verified according to the international criteria, the second group (control) - 7 people - healthy controls (m/f - 3/4, mean age - 23 [21; 26] years).
The phagocytic index and neutrophil activity in the NBT-test were calculated for all the examined patients. 0.008% solution of TiO2 (based on 1 mg / kg of body weight) was added to the test-samples, control samples were added with the physiological solution, standard samples - with a suspension of killed Staphylococcus aureus. All the samples were incubated for 30 minutes at 37°C, the ready smears were microscopied with counting the amount of formazan-positive granulocytes in the NST-test and cells that absorbed 1 or more Stf particles per 100 granulocytes.
Results. TiO2 stimulated phagocytosis of staphylococcus with blood neutrophils in 53% of the examined patients by 8-30% (p = 0.02). Under the influence of TiO2 activity of phagocytes significantly increased, in comparison with that in spontaneous NST-test (p = 0.0001), but was lower than induction by staphylococcus (p = 0.049).
In patients with allergopathology, TiO2 stimulated phagocytosis of staphylococcus and neutrophil activity in the NBT-test was also effective, as was the culture of staphylococcus aureus (31.2% compared to 34.3%).
In the healthy group, the TiO2 solution increased the activity of neutrophils in the NST-test, compared with the physiological solution (on average and in 71% of cases by 10-18%), but not so than the culture of staphylococcus (24%, compared to 39, 7%).
Among healthy people, there was a correlation between the hereditary of allergy and the neutrophil activity in the NBT-test with TiO2 (0.78).
Conclusions. It was found that 0.008% solution of TiO2 stimulated the activity of neutrophils in the NBT-test, both in patients with atopic bronchial asthma and healthy people after 30 minutes of incubation in a thermostat. In patients with allergies, TiO2 increased phagocytosis of staphylococcus, as well as metabolic activity of neutrophils so much as staphylococcus. A strong correlation was found between the hereditary allergies and the increased metabolic activity of blood phagocytes in the NBT-test with TiO2 in healthy individuals.