High prevalence of Human Herpesvirus 8 in schizophrenic patients

Sexually transmitted infections, sexual life and risk behaviours of people living with schizophrenia: systematic review and meta-analysis

BACKGROUND

Sexually transmitted infections (STIs), along with sexual health and behaviour, have received little attention in schizophrenia patients.

AIMS

To systematically review and meta-analytically characterise the prevalence of STIs and sexual risk behaviours among schizophrenia patients.

METHOD

Web of Science, PubMed, BIOSIS, KCI-Korean Journal Database, MEDLINE, Russian Science Citation Index, SciELO and Cochrane Central Register were systematically searched from inception to 6 July 2023. Studies reporting on the prevalence or odds ratio of any STI or any outcome related to sexual risk behaviours among schizophrenia samples were included. PRISMA/MOOSE-compliant (CRD42023443602) random-effects meta-analyses were used for the selected outcomes. Q-statistics, I2 index, sensitivity analyses and meta-regressions were used. Study quality and publication bias were assessed.

RESULTS

Forty-eight studies (N = 2 459 456) reporting on STI prevalence (including 15 allowing for calculation of an odds ratio) and 33 studies (N = 4255) reporting on sexual risk behaviours were included. Schizophrenia samples showed a high prevalence of STIs and higher risks of HIV (odds ratio = 2.11; 95% CI 1.23-3.63), hepatitis C virus (HCV, odds ratio = 4.54; 95% CI 2.15-961) and hepatitis B virus (HBV; odds ratio = 2.42; 95% CI 1.95-3.01) infections than healthy controls. HIV prevalence was higher in Africa compared with other continents and in in-patient (rather than out-patient) settings. Finally, 37.7% (95% CI 31.5-44.4%) of patients were sexually active; 35.0% (95% CI 6.6-59.3%) reported consistent condom use, and 55.3% (95% CI 25.0-82.4%) maintained unprotected sexual relationships.

CONCLUSIONS

Schizophrenia patients have high prevalence of STIs, with several-fold increased risks of HIV, HBV and HCV infection compared with the general population. Sexual health must be considered as an integral component of care.

Infections and schizophrenia

This paper provides a critical review of the literature, demonstrating a certain pathogenetic role of various infections, primarily viruses from the herpes and chlamydia groups, in the development and progression of schizophrenia, including published results of the authors’ own long-term studies.

Bioinformatics analysis of long non-coding RNA-associated competing endogenous RNA network in schizophrenia

Schizophrenia (SCZ) is a serious psychiatric condition with a 1% lifetime risk. SCZ is one of the top ten global causes of disabilities. Despite numerous attempts to understand the function of genetic factors in SCZ development, genetic components in SCZ pathophysiology remain unknown. The competing endogenous RNA (ceRNA) network has been demonstrated to be involved in the development of many kinds of diseases. The ceRNA hypothesis states that cross-talks between coding and non-coding RNAs, including long non-coding RNAs (lncRNAs), via miRNA complementary sequences known as miRNA response elements, creates a large regulatory network across the transcriptome. In the present study, we developed a lncRNA-related ceRNA network to elucidate molecular regulatory mechanisms involved in SCZ. Microarray datasets associated with brain regions (GSE53987) and lymphoblasts (LBs) derived from peripheral blood (sample set B from GSE73129) of SCZ patients and control subjects containing information about both mRNAs and lncRNAs were downloaded from the Gene Expression Omnibus database. The GSE53987 comprised 48 brain samples taken from SCZ patients (15 HPC: hippocampus, 15 BA46: Brodmann area 46, 18 STR: striatum) and 55 brain samples taken from control subjects (18 HPC, 19 BA46, 18 STR). The sample set B of GSE73129 comprised 30 LB samples (15 patients with SCZ and 15 controls). Differentially expressed mRNAs (DEmRNAs) and lncRNAs (DElncRNAs) were identified using the limma package of the R software. Using DIANA-LncBase, Human MicroRNA Disease Database (HMDD), and miRTarBase, the lncRNA- associated ceRNA network was generated. Pathway enrichment of DEmRNAs was performed using the Enrichr tool. We developed a protein-protein interaction network of DEmRNAs and identified the top five hub genes by the use of STRING and Cytoscape, respectively. Eventually, the hub genes, DElncRNAs, and predictive miRNAs were chosen to reconstruct the subceRNA networks. Our bioinformatics analysis showed that twelve key DEmRNAs, including BDNF, VEGFA, FGF2, FOS, CD44, SOX2, NRAS, SPARC, ZFP36, FGG, ELAVL1, and STARD13, participate in the ceRNA network in SCZ. We also identified DLX6-AS1, NEAT1, MINCR, LINC01094, DLGAP1-AS1, BABAM2-AS1, PAX8-AS1, ZFHX4-AS1, XIST, and MALAT1 as key DElncRNAs regulating the genes mentioned above. Furthermore, expression of 15 DEmRNAs (e.g., ADM and HLA-DRB1) and one DElncRNA (XIST) were changed in both the brain and LB, suggesting that they could be regarded as candidates for future biomarker studies. The study indicated that ceRNAs could be research candidates for investigating SCZ molecular pathways.

Assessment of cognitive impairment in HSV-1 positive schizophrenia and bipolar patients: Systematic review and meta-analysis

A common characteristic among schizophrenia and bipolar disorder patients is cognitive dysfunction, especially for memory and attention. Recent evidence has suggested that cognitive impairment in schizophrenia and bipolar disorder patients could be associated with herpes simplex virus 1 (HSV-1) infection, due to the ability of HSV-1 to infect neurons in the temporal lobe, which plays a key role in the formation of memory and processing of sensory input. The objective of this review is to analyze the aggregate neuropsychological testing data from previous studies regarding the impact of HSV-1 infection on cognitive function in schizophrenia and bipolar disorder. A systematic literature search generated a total of 379 articles; 12 full-text case control and cross-sectional studies met the eligibility criteria to be included in the review. Pooled effects assessed the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) total scores and the three index scores for immediate memory, delayed memory, and attention in a random effects model. The overall effect for RBANS total score was in favor of the HSV-1 positive group (z = 3.10, p = 0.002). A statistically significant overall effect of cognitive impairment for memory and attention indices was in favor of HSV positive schizophrenia patients (z = 5.95 p < 0.00001). The findings from the meta-analysis suggest that serological evidence of HSV-1 infection has a significant impact on cognitive function with small to moderate effect sizes (-0.23 to -0.49), particularly affecting memory and attention, in schizophrenia and bipolar patients.

Type specific Real time PCR for detection of human herpes virus 6 in schizophrenia and bipolar patients: a case control study

BACKGROUND

Schizophrenia (SC) and bipolar disorder (BD) are among the most devastating diseases worldwide. There are several lines of evidence suggesting that viruses may play significant roles in the etiology of these mental disorders. The aim of this study was the detection of HHV-6A/B in the peripheral blood mononuclear cells (PBMC) of SC and BD patients versus the healthy control (HC) subjects using a new method of type-specific Real time PCR analysis.

METHODS

A type-specific Real time PCR was performed for simultaneous detection and typing of HHV-6A/B in the PBMCs of 120 SC and BD patients and 75 HCs.

RESULTS

Only one case of HHV-6B out of 120 (0.8 %) SC and BD patients and two cases of HHV-6A (2.7 %) in 75 HCs were detected.

CONCLUSIONS

The low levels of HHV-6 detection in PBMCs, severely limited the capacity of this study to investigate the association between the presence of HHV-6 and BD or SC in this population, thus no conclusions can be drawn in this regard. Meanwhile this study introduces a Real time PCR based method for type specific detection of HHV-6A/B in clinical samples.

Schizophrenia and psychoneuroimmunology: an integrative view

PURPOSE OF REVIEW

Since decades immunological aberrancies have been reported in schizophrenia patients. As schizophrenia represents a heterogenous disorder with a variety of clinical manifestations, complex interactions between the immune system in the brain might have important etiological implications.

RECENT FINDINGS

Recent findings of altered expression of immune-related genes, changes of peripheral and central cytokines, antibodies and immune cells point toward dysbalanced immune response processes in schizophrenia.

SUMMARY

Based on immunogenetic factors, immune dysfunctions caused by infections, increased autoimmune reactivity and low-grade inflammatory processes in the periphery as well as in central nervous system may affect neurobiological circuits including changed neurotransmitter metabolisms contributing to pathophysiological alterations in schizophrenia. These immunological abnormalities might provide tools for better diagnostic characterization of this heterogenous disease and on the other side, they may also support the development of immune-related therapeutic strategies.