Glutamine depletion and heat shock protein 70 (HSP70) in children with meningococcal disease

Abstract

Heat shock proteins are classified into six main families, of which HSP70 is the best studied. HSP70 is postulated to modulate the immune/inflammatory response in critical illness. Glutamine promotes HSP70 release, however, little is known about the relationship between glutamine and HSP70 in paediatric critical illness. We therefore aimed to describe plasma levels of HSP70, inflammatory mediators and glutamine in critically ill children. A clinical audit identified 143 children with severe meningococcal disease, 78 convalescent children, in addition to 35 healthy paediatric controls. Stored plasma was used to measure plasma concentrations of HSP70, inflammatory mediators and glutamine. HSP70 was significantly increased on admission (n = 143, mean 26.7 ng/ml; ±SD 79.95) compared with convalescence (n = 78, mean 3.16 ng/ml; ±SD 5.67). Glutamine levels were low (n = 132, mean 0.31 mmol/l; ±SD 0.13), which continued in convalescence (n = 65, mean 0.40 mmol/l; ±SD 0.14). Enteral glutamine provided only 28% of the recommendations. Glutamine was inversely correlated with length-of-stay (n = 98, r = -0.520, p < 0.001), ventilation (n = 98, r = -0.513, p < 0.001), lactate (n = 98, r = -0.41, p < 0.001) and CRP (n = 98, r = -0.51, p < 0.001). HSP70 was correlated with length-of-stay (n = 99, r = 0.30, p < 0.001), ventilation (n = 99, r = 0.31, p < 0.001), lactate (n = 99, r = 0.26, p < 0.001) and CRP (n = 99, r = 0.29, p < 0.001) and inflammatory mediators. There was no relationship between glutamine and HSP70 or inflammatory mediators. During acute illness HSP70/inflammatory mediators are significantly increased, and glutamine is significantly depleted. However, glutamine and HSP70 were not correlated. Enteral feeds only provided a small proportion of the ASPEN/ESPEN recommendations for glutamine.