Circulating interleukin-6, tumour necrosis factor soluble receptor-II, interleukin-1 receptor antagonist, and serum procalcitonin in patients with heat stroke: Prognostic implications

Abstract

Heat Stroke (HS) is frequently fatal illness that usually occurs episodically as clusters of patients presenting to the emergency room. We have studied 26 patients with HS incurred during the religious pilgrimage to Makkah at (0, 6, 12, 24 hr) and found that the level of IL-Ira, TNF SR II and IL-6 are elevated. It appears such elevation are required for and are part of acute phase response and recovery. However markedly elevated cytokines are associated with mortality. We also found the precursors to the hormone calcitonin: Procalcitonin are greatly increased in patients with this condition. Although serum levels are high upon admission (3.4±1.0 ng/ml vs 0.17±0.04 ng/ml for a febrile emergency room control (P=0.012), even higher levels occured at 6 hours 25.1±6.4 ng/ml, (P<0.0001). Among the 6 patients who died 4 of them had levels indistinguishable from control subjects, the other 2 patients who had high levels, had additional medical complications. Chi-square analysis of categorized Pro CT revealed a significant positive correlation between Pro CT and survival. Our study shows that the level of IL-Ira, TNF SR II and IL-6 are increased in HS and associated with mortality and also it may suggest that the hyperprocalcitoninemia may be related to the post-injury cytokine cascade. The mechanism by which hyperprocalcitoninemic response is elicited in surviving HS patients, but fail to occur in most of those who do not survive requires further study.