Table 1.
Studies assessing inflammatory/immune markers and cognition in schizophrenia.
| Authors | Year | N | Control type | Cognitive Functions and Instruments | Inflammatory Markers | Results | Conclusions |
|---|---|---|---|---|---|---|---|
| Dickerson et al. | 2007 | 413 SZ patients. | Patients divided by CRP levels (high or low). No healthy controls. | RBANS (based on 5 scales: immediate and delayed memory, visuo-constructional, language and attention) | CRP levels (˂ 5.0 mg/μl or ≥ 5.0 mg/μl) |
p=0.0047 (PCR negatively associated to RBANS) | CRP levels related to cognitive impairment measured by RBANS composite score in SZ. |
| Dickerson et al. | 2012 | 588 SZ patients. | Patients divided in four groups, according to HSV-1 serological status and CRP levels. No healthy controls. | RBANS | CRP levels (˂ 5.0 mg/μl or ≥ 5.0 mg/μl (and HSV1 status) |
Effect sizes on RBANS were .10 for HSV1+, .10 for high CRP, .14 for HSV1+ and high CRP together. | Additive effects of elevated CRP and exposure to HSV-1 in cognitive impairment in SZ. |
| MartÍnez-Cengotitabengoa et al. | 2012 | 28 First Episode Psychosis patients. | 28 healthy controls. | Fluency Assessment Scale, WAIS III, TMTA, TMTB Stroop Color and Word Test, WMS III, WCST. | MCP-1 (and oxidative stress markers). | Negative association between MCP-1 levels and learning and memory (p=0.009). | Learning, verbal and working memory correlates inversely with chemokine levels and executive function directly to antioxidant markers in first psychotic episodes. |
| Zhang et al. | 2013 | 77 First Episode and Drug NaÏve SZ patients | 75 healthy, gender, education and age-matched controls. | RBANS | IL-18 serum levels. | Positive association between IL-18 levels and RBANS visuospatial/constructional index (p=0.03). | IL-18 may be associated to cognitive deficits in SZ. Association was the opposite than expected, suggesting neuroprotection (hypothesis of antiviral activity). |
Abbreviations: CRP: C reactive protein, HSV1: Herpes Simplex Virus type 1, IL-18: interleukin 18, MCP-1: monocyte chemoattractant protein 1.RBANS: Repeatable Battery for the Assessment of Neuropsychological status, Th1/Th2: T helper cells type 1 and 2, SZ: schizophrenia, TMTA/B: Trail Making Test A and B, WAIS III: Wechsler Adult Intelligence Scale, WCST: Winconsin Card Sorting Test, WMS III: Wechsler Memory Scale