Mitochondrial DNA haplogroup R in the Han population and recovery from septic encephalopathy

Abstract

To determine whether the main mitochondrial DNA (mtDNA) haplogroups of the Han people are associated with neurological recovery from septic encephalopathy. We studied 137 individuals with septic encephalopathy who were sequentially admitted to the intensive care unit or the emergency intensive care unit at the First Affiliated Hospital, College of Medicine, Zhejiang University, and the People's Hospital of Zhejiang Province. Demographic and clinical data were recorded along with clinical outcome over 28days. The Glasgow coma scale (GCS) score was calculated daily until it reached 15 or until the patient died during the 28-day period. Follow-up was completed for all study participants. We then determined the mtDNA haplogroups of the patients by analyzing sequences of hypervariable mtDNA segments and testing diagnostic polymorphisms in the mtDNA coding region with DNA probes. MtDNA haplogroup R, one of the main mtDNA haplogroups of the Han people, was a strong independent predictor of outcome following septic encephalopathy, conferring a 4.053-fold (95% CI 1.803-9.110, p=0.001) increased chance of neurological recovery within 28days compared with those with a non-R mtDNA haplogroup. In the Han population, mtDNA haplogroup R is a strong independent predictor of the outcome of septic encephalopathy, conferring an increased chance of neurological recovery compared with individuals with a non-R haplogroup. Our results provide potential insights into the mechanisms involved in septic encephalopathy, and reveal that the mtDNA haplogroup R is an independent predictor of the outcome of septic encephalopathy.