Delayed encephalopathy after acute carbon monoxide poisoning: a case study

Delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) is a relatively rare inflammatory-associated neurometabolic complication. In this article, we present a case report of a 50-year-old male patient with a history of carbon monoxide poisoning. This acute poisoning, although successfully controlled during a stay in the intensive care unit of a local hospital, later led to persistent neurological symptoms. The patient was then treated in the inpatient unit of the rehabilitation clinic, where cognitive deterioration began to develop 20 days after admission. Subsequent examination using EEG and magnetic resonance imaging confirmed severe encephalopathy later complicated by SARS-CoV-2 infection with fatal consequences due to bronchopneumonia. Because currently there are no approved guidelines for the management of DEACMP, we briefly discuss the existing challenges for future studies, especially the application of rational immunosuppressive therapy already in the acute treatment phase of CO poisoning, which could prevent the development of a severe form of DEACMP.

Investigation of the relationship between MBP gene polymorphisms and delayed encephalopathy after acute carbon monoxide poisoning

Increasing evidence reveals that delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) results from the combined effects of environmental and genetic factors. The main pathological feature of DEACMP was generalized demyelination of cerebral white matter. Myelin basic protein (MBP) levels in cerebrospinal fluid (CSF) and serum samples from DEACMP patients were elevated. This study investigated the association of MBP single nucleotide polymorphisms(SNPs) (rs470555, rs470724, rs4890785, rs595997, rs76452994, and rs921336) with DEACMP. We genotyped 416 DEACMP patients and 785 age, educational level, and sex-matched ACMP patients for rs470555, rs470724, rs4890785, rs595997, rs76452994, and rs921336 SNPs using the Agena MassArray. There were no significant differences in the allele frequency distribution, four genetic models, and genotype distributions between the DEACMP and ACMP groups for rs470555, rs470724, rs4890785, and rs595997. However, significant differences were observed for rs76452994 and rs921336. This study revealed that the MBP polymorphisms, rs470555, rs470724, rs4890785, and rs595997, were not associated with DEACMP. Based on the codominant, dominant, and overdominant genetic inheritability patterns, the MBP rs76452994 and rs921366 polymorphisms were associated with DEACMP. Furthermore, the G allele of rs76452994 and T allele of rs921336 could lead to higher DEACMP risk.

The Relationship between Cadherin Polymorphisms and the Risk of Delayed Encephalopathy after Acute Carbon Monoxide Poisoning in the Chinese Han Population

Objective

The purpose of this study was to analyze the relationship between cadherin gene single-nucleotide polymorphisms (SNPs) and the risk of delayed encephalopathy after acute carbon monoxide poisoning (DEACMP).

Materials and Methods

A total of 416 patients with DEACMP and 754 patients with acute carbon monoxide poisoning (ACMP) were recruited. We used the Sequenom MassARRAY® system to detect cadherin gene SNPs related to DEACMP. Using different genetic analysis models, we evaluated the relationship between the cadherin gene polymorphisms and risk of DEACMP.

Results

We found that rs1944294 in the N-cadherin (CDH2) gene showed significant differences in genotype frequencies between the two groups under codominant and dominant inheritance models. Similarly, rs2513796 in the cadherin-17 (CDH17) gene showed significant differences under the codominant, dominant, and overdominant genetic models. And the T allele frequency of rs1944294 in the DEACMP group was significantly higher than that in the ACMP group (P = 0.023).

Conclusions

Cadherin gene SNPs (rs1944294, rs2513796) are associated with an increased risk of DEACMP in the Chinese population.

DNA pooling base genome-wide association study identifies variants at NRXN3 associated with delayed encephalopathy after acute carbon monoxide poisoning

Delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) is more characteristic of anoxic encephalopathy than of other types of anoxia. Those who have the same poisoning degree and are of similar age and gender have a greater risk of getting DEACMP. This has made it clear that there are obvious personal differences. Genetic factors may play a very important role. The authors performed a genome-wide association study involving pooling of DNA obtained from 175 patients and 244 matched acute carbon monoxide poisoning without delayed encephalopathy controls. The Illumina HumanHap 660 Chip array was used for DNA pools. Allele frequencies of all SNPs were compared between delayed encephalopathy after acute carbon monoxide poisoning and control groups and ranked. A total of 123 SNPs gave an OR >1.4. Of these, 46 mapped in or close to known genes. Forty-eight SNPs located in 19 genes were associated with DEACMP after correction for 5% FDR in the genome-wide association of pooled DNA. Two SNPs (rs11845632 and rs2196447) locate in the Neurexin 3 gene were selected for individual genotyping in all samples and another cohort consisted of 234 and 271 controls. There were significant differences in the genotype and allele frequencies of rs11845632 and rs2196447 between the DEACMP group and controls group (all P-values <0.05). This study describes a positive association between Neurexin 3 and controls in the Han Chinese population, and provides genetic evidence to support the susceptibility of DEACMP, which may be the resulting interaction of environmental and genetic factors.