Adaptive and inflammatory immune responses in patients infected with strains of Vibrio parahaemolyticus

Abstract

In patients with diarrhea caused by Vibrio parahaemolyticus antibody-secreting cell responses to thermostable direct hemolysin (TDH), lipopolysaccharide (LPS), and whole-cell bacteria were seen. TDH- and LPS-specific responses were seen in serum samples, and immunoglobulin A antibody responses were observed in stool. Levels of C-reactive protein and nitric oxide metabolites increased in the systemic circulation at the onset of illness. Tumor necrosis factor-a and lactoferrin levels were high during the acute stage in mucosal secretions and in plasma, whereas interleukin-1β levels were high only in mucosal secretions. Duodenal and rectal biopsy specimens obtained at the onset of illness showed an acute inflammatory response. The lamina propria showed edema, congestion of blood vessels, and hemorrhage, with an increase in levels of polymorphonuclear neutrophils and macrophages. Strains belonging to different serotypes exhibited varying resistance to killing by serum; the O8:K21 strain was most sensitive. Infection with V. parahaemolyticus results in B cell responses and an acute inflammatory response that is self-limiting