Phagocytic and bactericidal activity and morphological parameters of blood platelets in patients with Trichinella spiralis infection.

PURPOSE The production of IgE increases in parasitic invasions, triggering local or systemic inflammatory response with the involvement of blood platelets. The aim of the study was to assess the number and morphological parameters of blood platelets as well as their phagocytic and bactericidal activity in patients with Trichinella spiralis infection. It is interesting to investigate the blood platelet response following Trichinella spiralis in order to elucidate possible effects on non-specific immunity. MATERIAL AND METHODS Twenty-six patients with Trichinella spiralis (before and after antiparasitic therapy) and forty healthy subjects were examined. The platelet count and morphological parameters were determined using a hematologic analyzer Technicon H-1 System. The platelet phagocytic activity was determined by measuring the percentage of phagocytizing cells and the phagocytic index. The bactericidal activity was assessed measuring the percentage of the bacteria killed by platelets and plasma. The strain Staphylococcus aureus ATCC 6538P was used for this purpose. RESULTS In patients infected with T. spiralis morphological parameters do not change, except for the percentage of large platelets. In the course of trichinellosis the phagocytic index of platelets is statistically significantly decreased and platelet bactericidal activity is impaired, while the bactericidal activity of the plasma is statistically significantly increased, compared to healthy subjects. CONCLUSIONS The present study has revealed that due to T. spiralis infection, the percentage of large, young blood platelets is decreased. The parasitic infection causes impairment of non-specific immunity through decreased bactericidal activity of blood platelets.