Ammonia level and Alzheimer type 2 astrocytes in the brain of deceased patients with liver cirrhosis of the varying degree

Abstract

The aim of the study – comparative analysis of the ammonia level and Alzheimer type 2 astrocytes in the brain cortex and white matter of cerebral hemispheres, hippocampus, thalamus, striatum and cerebellum in the deceased patients with liver cirrhosis of classes A, B and C according to Child–Pugh. Materials and methods. The study was performed on the brain of deceased 90 patients (65 ± 3 years) suffered from non-alcoholic liver cirrhosis (LC) of classes A (n = 30, group “A”), B (n = 30, group “B”) and C (n = 30, group “C”) according to Child–Pugh score, among which 59 (65.55 %) patients had clinical symptoms of hepatic encephalopathy of I–IV grades. The control group included postmortem brains of 30 patients (59.0 ± 2.5 years) who died from acute cardiovascular insufficiency and did not suffer from liver diseases or intoxication. A retrospective analysis of clinical and laboratory data from case histories was carried out. For histochemical (HC) determination of the ammonia in paraffin sections of the cerebral cortex and white matter, hippocampus, thalamus, striatum and cerebellum we used the protocol with Nessler’s reagent proposed by Gutierrez-de-Juan et al. (2017). In the noted brain regions, the analysis of HC ammonia optical density was performed in five standardized fields of view (×200) of the microscope scope A1 “Carl Zeiss” (Germany) with Jenoptik camera progress Gryphax 60 N-C1ꞌꞌ1.0x426114 (Germany) using ImageJ software; in each noted brain region the number of Alzheimer’s type 2 astrocytes (AA2) was counted per twenty standardized fields of view at magnification ×400. Results. HC method for ammonia detection with Nessler’s reagent according to V. Gutiérrez-de-Juan et al. (2017) reveals region-dependent fine-grained expression of ammonia in the brain neuropil of deceased patients in control and cirrhotic groups. In control patients, a very low HC ammonia expression is observed with higher values in cerebellum, thalamus, and striatum, while still ranked as negative. Increased HC ammonia expression (compared to control) is observed in deceased patients with compensated LC of “A” group in the cortex, thalamus, striatum and cerebellum; in subcompensated LC of “B” group – as well in the white matter and hippocampus. In deceased patients with decompensated LC of “C” group, in cerebellum, thalamus and striatum HC ammonia expression is maximally increased (by 6.18, 5.72, and 5.50 folds, respectively). Significant correlations are present between patients’ postmortem brain HC ammonia expression and the last intravital indicators of the blood total bilirubin, AST, ALT, albumin, leukocytic intoxication index. In compensated cirrhosis, increase in AA2 numbers compared to control is found in thalamus, striatum and cerebellum, which corresponds to AA2-astrocytosis of I degree. In subcompensated cirrhosis, AA2-astrocytosis of moderate II degree is found in the cortex, thalamus and cerebellum; AA2-astrocytosis of I degree – in striatum. In decompensated cirrhosis, pronounced AA2-astrocytosis of III degree is determined in the cortex, thalamus, striatum and cerebellum; moderate AA2-astrocytosis of II degree – in cerebral white matter, and mild AA2-astrocytosis of I degree – in the hippocampus. There is a moderate, strong, and very strong positive relationship between the levels of AA2-astrocytosis and HC ammonia expression in the thalamus, striatum, and cerebellum. Conclusions. In deceased patients with LC, the neuropil HC ammonia expression in cerebellum, thalamus, striatum, and cerebral cortex directly correlates with the severity of LC according to Child–Pugh, reaching a maximum in LC of class C, and has significant correlations with intravital blood levels of total bilirubin, AST, ALT, albumin, leukocytic intoxication index. With LC progression, AA2-astrocytosis increases significantly in thalamus, cerebellum, striatum and cerebral cortex, which positively correlates with HC ammonia expression in these brain regions.