The following is a summary of “Association between cognitive function and IL-18 levels in schizophrenia: Dependent on IL18 − 607 A/C polymorphism,” published in the December 2023 issue of Psychoneuroendocrinology by Guan et al.

There is more and more proof that a dysregulated immune system is linked to brain growth problems in people with schizophrenia (SZ). Cognitive decline is a long-lasting trait that starts with SZ and stays with the person throughout the disease. Some early research has shown that high levels of interleukin (IL)-18 combine with IL18 polymorphism and are linked to mental symptoms in SZ. For a study, researchers sought to determine if high amounts of IL-18 combined with the -607 A/C gene to determine cognitive loss in people with chronic SZ. 

They got 693 inpatients and 422 healthy controls to test for IL-18 and find out the genotype of the − 607 A/C variation. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was also used to measure brain ability. They discovered that the levels of IL-18 in the blood were higher in patients than in healthy controls. IL18–607 A/C levels were not linked to either patients or healthy controls.  Also, − 607 A/C was only linked to the visuospatial/constructional score in patients. 

The study showed that IL-18 levels were linked to better short-term memory only in people with the C/C gene and not in people with the C/A or A/A genotype. It showed that the link between IL-18 and brain function was contingent upon the IL18–607 A/C polymorphism in SZ cases.

Source: sciencedirect.com/science/article/abs/pii/S0306453023003645