Expressions and significance of aquaporin-4 in children with severe hand-foot-mouth disease

Abstract

Objective To explore the levels of water channel protein 4 (aquaporin-4, AQP-4) in the serum and the cerebrospinal fluid of patients with severe hand-foot-mouth disease (HFMD) and its clinical significance. Methods Children with the critical HFMD (clinical stage 3) admitted to Xuzhou Children′s Hospital from February 2017 to November 2017 were recruited(critical group). In the same period, another 25 cases of common HFMD (central nervous system infection excluded in cerebrospinal fluid examination, common group), the other 25 cases of severe HFMD (clinical stage 2, severe group) were taken as the controls.The levels of AQP-4 in the serum and and cerebrospinal fluid were measured in all children and the levels of AQP-4 in cerebrospinal fluid were checked again in the critical and severe cases after treatment.The levels of interleukin-6(IL-6), norepinephrine(NE) and neuron-specific enolase(NSE) in the serum were examined simultaneously and the correlation between them was analyzed. Results Before treatment, the levels of AQP-4 in the serum of critical group were(54.42±19.86) μg/L, which were significantly higher than common group[(8.02±1.59) μg/L] and severe group[(22.04±8.14) μg/L] (F=36.684, P<0.01). Compared with before treatment, the levels of AQP-4 in the serum of critical and severe group were significantly lower after treatment (P<0.05). Before treatment, the levels of AQP-4 in the cerebrospinal fluid of critical and severe cases were respectively (9.81±2.27) μg/L and (8.58±1.92) μg/L, which were significantly higher than common group(6.56±1.79) μg/L(F=6.713, P<0.05). After treatment, the levels of AQP-4 in the cerebrospinal fluid of critical and severe cases were (8.41±1.63) μg/L and (7.14±1.69) μg/ L separately, which were significantly lower than before treatment (t=6.340, 5.073, all P<0.01). The levels of IL-6, NE and NSE in serum were significantly different among the three groups(P<0.01). The above indicators were positively correlated with the levels of AQP-4 in the serum(r=0.734, 0.810, 0.729, all P<0.01)and were also positively correlated with AQP-4 in the cerebrospinal fluid(r=0.299, 0.431, 0.363, all P<0.05). Conclusion AQP-4 may participate in pathophysiological processes of HFMD.The levels of AQP-4 in serum can be used as an indicator for judging the severity and monitor prognosis of HFMD. Key words: Aquaporin-4; Hand-foot-mouth disease; Interleukin-6; Norepinephrine; Neuron-specific enolase