Increased nitric oxide production by neutrophils from patients with chronic granulomatous disease on trimethoprim–sulfamethoxazole

Abstract

Chronic granulomatous disease (CGD) is an inherited disease characterized by severe and recurrent bacterial and fungal infections. Phagocytic cells of CGD patients are unable to produce superoxide anion, and their efficiency in bacterial killing is significantly impaired. In these patients, the prophylactic and therapeutic validity of a long-term use of trimethoprim–sulfamethoxazole (TMP–SMX) has been well established. However a role of nitric oxide (NO) produced by phagocytic cells from CGD patients is unknown, and the mechanism of TMP–SMX in CGD is unclear. We have directly measured NO production in whole human blood by using 4,5-diaminofluorescein as a novel fluorescent indicator for intracellular NO. Intracellular NO production of gated neutrophils increased time dependently when stimulated by lipopolysaccharide (LPS) and calcium ionophore. Although all polymorphonuclear leukocyte (PMN) specimens from patients with CGD failed to generate hydrogen peroxide, NO production by CGD PMNs was significantly increased compared with that of control PMNs ( p<0.05). TMP–SMX with LPS significantly increased compared with LPS-stimulated samples at clinical ( n=5, p<0.05) and 10-fold clinical concentrations ( n=5, p<0.01). TMP–SMX with LPS in CGD PMNs significantly increased the production of NO in comparison with the LPS stimulation at 10-fold clinical concentrations ( n=5, p<0.05). In conclusion, our data indicate the possibility that NO production by neutrophils from patients with CGD treated with TMP–SMX has a role of bactericidal activity instead of O 2 − in host defense mechanism.