Decrease of respiratory burst in neutrophils of patients with ankylosing spondylitis by combined radon-hyperthermia treatment

Objective To define the respiratory burst activity of neutrophils, the total anti-oxi dative status of plasma and the parameters of systemic inflammation inpatie nts with ankylosing spondylitis (AS) before and after a combined radon-hype rthermia treatment in the thermal tunnels of Bockstein-Bad Gastein in Austr ia. Methods In 20 patients with AS the effects of a total of 25 hours of radon-hyperthe rmia-treatment spread over a period of three weeks were studied. The respir atory burst activity of neutrophils was measured fluorometrically using dic hlorofluorescein diacetate, the total anti-oxidant status was measured usin g azinodiethyl-benzthiazoline-sulphonate, and inflammation parameters were determined by routine laboratory assays. Results Before treatment, the basal neutrophil respiratory burst in patients (n = 2 0) was 409 +/- 62 fluorescence arbitrary units (AU; mean +/- SEM) and 359 /- 37 AU in controls (n = 9; p > 0.5); the stimulated respiratory burst (fM et-Leu-Phe, 10(-6) M) was 1,027 +/- 133 AU in patients and 1,152 +/- 218 AU in controls (p > 0.5). After treatment the basal neutrophil respiratory bu rst in patients (n = 19) was 137 +/- 16 and in controls it was 174 +/- 35 A U (n = 8; p > 0.1); the stimulated respiratory burst was 670 +/- 66 and 1,3 05 +/- 82 AU, in patients and controls respectively (p < 0.001). No effects of treatment on the total anti-oxidant status of the plasma or on the para meters of inflammation were detected. Conclusion Combined radon-hyperthermia treatment reduces the respiratory burst activit y of the blood circulating neutrophils in patients with AS. If respiratory burst activity from the neutrophils plays a role in the pathophysiology of ankylosing spondylitis, the observed reduction may be related to the benefi cial effects of radon hyperthermia treatment.