Immune Cell Neurotrophin Production Is Associated with Subcortical Brain Atrophy in Neuropsychiatric Systemic Lupus Erythematosus Patients

Nerve Growth Factor and Autoimmune Diseases

NGF plays a crucial immunomodulatory role and increased levels are found in numerous tissues during autoimmune states. NGF directly modulates innate and adaptive immune responses of B and T cells and causes the release of neuropeptides and neurotransmitters controlling the immune system activation in inflamed tissues. Evidence suggests that NGF is involved in the pathogenesis of numerous immune diseases including autoimmune thyroiditis, chronic arthritis, multiple sclerosis, systemic lupus erythematosus, mastocytosis, and chronic granulomatous disease. Furthermore, as NGF levels have been linked to disease severity, it could be considered an optimal early biomarker to identify therapeutic approach efficacy. In conclusion, by gaining insights into how these molecules function and which cells they interact with, future studies can devise targeted therapies to address various neurological, immunological, and other disorders more effectively. This knowledge may pave the way for innovative treatments based on NGF manipulation aimed at improving the quality of life for individuals affected by diseases involving neurotrophins.

Blood levels of brain-derived neurotrophic factor (BDNF) in systemic lupus erythematous (SLE): a systematic review and meta-analysis

OBJECTIVES

BDNF has been implicated in the pathophysiology of systemic lupus erythematosus (SLE), especially its neuropsychiatric symptoms. The purpose of this study was to investigate the profile of blood BDNF levels in patients with SLE.

METHODS

We searched PubMed, EMBASE, and the Cochrane Library for papers that compared BDNF levels in SLE patients and healthy controls (HCs). The Newcastle-Ottawa scale was used to assess the quality of the included publications, and statistical analyses were carried out using R 4.0.4.

RESULTS

The final analysis included eight studies totaling 323 healthy controls and 658 SLE patients. Meta-analysis did not show statistically significant differences in blood BDNF concentrations in SLE patients compared to HCs (SMD 0.08, 95% CI [ - 1.15; 1.32], P value = 0.89). After removing outliers, there was no significant change in the results: SMD -0.3868 (95% CI [ - 1.17; 0.39], P value = 0.33. Univariate meta-regression analysis revealed that sample size, number of males, NOS score, and mean age of the SLE participants accounted for the heterogeneity of the studies (R² were 26.89%, 16.53%, 18.8%, and 49.96%, respectively).

CONCLUSION

In conclusion, our meta-analysis found no significant association between blood BDNF levels and SLE. The potential role and relevance of BDNF in SLE need to be further examined in higher quality studies.

Depression, anxiety, and sleep quality in childhood onset systemic lupus erythematosus and relationship with brain-derived neurotrophic factor

Background

The association between brain-derived neurotrophic factor (BDNF) and systemic lupus erythematosus (SLE) is controversial, and no study investigated the clinical associations of BDNF in patients with childhood onset systemic lupus erythematosus (cSLE). In this study, we aimed to investigate the serum levels of BDNF in patients with cSLE and examine whether a relationship of BDNF exists among depression, anxiety, and sleep quality.

Methods

Thirty patients and age-sex matched healthy controls were included. Depression, anxiety, sleep quality and quality of life were assessed by relevant questionnaires. Disease activity was assessed according to the SLE disease activity index (SLEDAI) and serum BDNF level was measured by the enzyme-linked immunosorbent assay method.

Results

Serum BDNF level was significantly lower in cSLE patients than healthy controls (21981 vs 29905 pg/mL, p = 0.001) and significantly decreased level was observed in active cSLE (SLEDAI >0), then those with SLEDAI = 0 (17110 vs 26852 pg/mL, p = 0.005). Although the scores of the depression, anxiety, sleep quality and quality of life questionnaires were strongly correlated with each other, no correlation was observed with serum BDNF levels.

Conclusions

In patients with cSLE, serum level of BDNF was significantly decreased compared to healthy controls. Our results suggest that serum BDNF levels were not associated with the presence of anxiety, depression and poor sleep quality and might be dictated by the pathophysiological process of SLE rather than mood disorders.

Serum BDNF and cognitive dysfunction in SLE: findings from a cohort of 111 patients

OBJECTIVE

The association between brain-derived neurotrophic factor (BDNF) and neuropsychiatric systemic lupus erythematosus (NPSLE) is controversial in the literature. Cognitive dysfunction (CD) is a common, underdiagnosed NPSLE manifestation, but its pathophysiology is unknown. Thus, we investigate serum BDNF as a potential biomarker of CD in a cohort of SLE patients.

METHODS

We included 63 SLE patients, 48 NPSLE, and 57 age- and gender-matched controls (CON). All participants underwent neuropsychological assessment. Data on cardiovascular comorbidities, SLE disease activity index (SLEDAI), and Systemic Lupus International Collaborating Clinics damage index (SLICC-DI) were compiled. Multiple regression analyses evaluated predictors of serum BDNF levels.

RESULTS

Serum BDNF levels were lower in SLE and NPSLE patients than in CON (SLE 800.4 ± 502.7 vs. NPSLE 779.7 ± 426.3 vs. CON 1,345.5 ng/mL ± 438.4; p < 0.001). In addition, hypertension (B: - 192.5, SE: 84.3, 95% CI: - 359.7 to - 25.3, p = 0.024) and SLICC-DI score (B: - 75.9, SE: 27.2, 95% CI: - 129.8 to - 22, p = 0.006) were predictors of serum BDNF levels in SLE. There was no relation between BDNF levels and CD.

CONCLUSION

BDNF levels are lower in SLE patients than CON and inversely associated with hypertension and SLICC-DI scores. No association between BDNF levels and CD or NPSLE was observed in this cohort. These findings indicate that BDNF may be associated with overall burden in SLE rather than specific manifestations such as cognition impairment. Key Points • BDNF is associated with an overall burden in SLE rather than specific manifestations such as cognition dysfunction. • BDNF levels are reduced in patients with SLE, and higher SLICC-DI scores and hypertension are independent predictors of lower serum BDNF levels. • The cognitive dysfunction rate is elevated (46%) among Brazilian SLE patients.

Plasma levels of nerve growth factor in Egyptian autistic children: Relation to hyperserotonemia and autoimmunity

Hyperserotonemia and brain-specific autoantibodies are detected in some autistic children. Nerve growth factor (NGF) stimulates the proliferation of B lymphocytes with production of antibodies and also increases mast cell serotonin release. This work was the first to investigate the relationship between plasma NGF and both hyperserotonemia and the frequency of serum anti-myelin basic protein (anti-MBP) auto-antibodies in 22 autistic children aged between 4 and 12 years and 22 healthy-matched controls. Levels of NGF, serotonin and anti-MBP were significantly higher in autistic children than healthy control children (P < 0.001). There was a significant positive correlation between NGF and serotonin levels in autistic patients (P < 0.01). In contrast, there was a non-significant correlation between NGF and anti-MBP levels (P > 0.05). In conclusions, serum NGF levels were elevated and significantly correlated to hyperserotonemia found in many autistic children.

Advances in the diagnosis, pathogenesis and treatment of neuropsychiatric systemic lupus erythematosus

PURPOSE OF REVIEW

Diagnosing and treating neuropsychiatric systemic lupus erythematosus (NPSLE) remains challenging as the pathogenesis is still being debated. In this review, we discuss studies evaluating recent advances in diagnostic methods, pathogenic mediators and potential treatments.

RECENT FINDINGS

Screening tools used for neurodegenerative diseases were found to be both sensitive and moderately specific for cognitive dysfunction in NPSLE. Neuroimaging can be used to distinguish systemic lupus erythematosus (SLE) patients from healthy controls, but further refinement is needed to differentiate between lupus patients with and without neuropsychiatric manifestations. Elevated levels of specific molecules in the cerebrospinal fluid and/or serum, as well as the presence of certain autoantibodies, have been identified as potential biomarkers in attempts to facilitate a more accurate and objective diagnosis. Among such autoantibodies, anti-NR2 and anti-ribosomal P autoantibodies also have a pathogenic role, although newer studies demonstrate that blood-brain barrier damage may not always be required as previously believed. These and other observations, together with new evidence for disease attenuation after microglial modulation, suggest direct involvement of the central nervous system in NPSLE pathogenesis.

SUMMARY

Neuropsychiatric involvement of SLE includes a variety of symptoms that impact quality of life and patient prognosis. There have been recent advances in improving the diagnosis of NPSLE as well as in dissecting the underlying pathogenesis. The attenuation of neuropsychiatric disease in mouse models demonstrates the potential for targeted therapies, which are based on a clearer understanding of the pathogenesis of NPSLE. Further assessment of these treatments is required in NPSLE patients, as well as the potential use of neuroimaging to distinguish between SLE patients with or without neuropsychiatric manifestations.

Interaction of BDNF and cytokines in executive dysfunction in patients with chronic schizophrenia

Multiple lines of evidence indicate that patients with chronic schizophrenia (SCZ) display executive dysfunction across the illness course. However, the potential molecular pathophysiologic mechanisms remain poorly elucidated. Neurodevelopmental changes caused by alterations of inflammatory mediators and neurotrophins have been shown to occur in the earliest stages of SCZ, and be associated with executive dysfunction (ED) in SCZ. Therefore, the current study was to investigate whether the interplay between BDNF and inflammatory mediators was involved in the disruption of executive function of long-term hospitalized patients with chronic SCZ. Serum cytokines and BDNF levels were measured in 112 long-term hospitalized patients with chronic SCZ and 44 healthy normal controls. Executive functions were assessed by verbal fluency tests (VFT), the Stroop word-color test (Stroop), and the Wisconsin card sorting tests (WCST).The results showed that the patients had higher IL-2, IL-6, IL-8, but lower TNF-α and BDNF compared to control subjects. In the patient group, BDNF was positively associated with IL-2 and IL-8 levels, while lower BDNF levels were correlated with ED measured by VFT and WCST tests. Multiple stepwise regression analyses confirmed that BDNF × IL-8 and BDNF × TNF-α were factors influencing the total score of VFT, while BDNF × IL-8 and BDNF × TNF-α were recognized as influencing factors for WCST scores. Our results suggest complex interactions between BDNF and cytokines were involved in the pathophysiology of executive function impairments in patients with SCZ.

Nerve Growth Factor Serum Levels Are Associated With Regional Gray Matter Volume Differences in Schizophrenia Patients

Numerous neuroimaging studies have revealed structural brain abnormalities in schizophrenia patients. There is emerging evidence that dysfunctional nerve growth factor (NGF) signaling may contribute to structural brain alterations found in these patients. In this pilot study, we investigated whether there was a correlation between NGF serum levels and gray matter volume (GMV) in schizophrenia patients. Further, we investigated whether there was an overlap between the correlative findings and cross-sectional GMV differences between schizophrenia patients (n = 18) and healthy controls (n = 19). Serum NGF was significantly correlated to GMV in the left prefrontal lobe, the left midcingulate cortex, and the brainstem in schizophrenia patients. However, we did not find any correlations of NGF serum levels with GMV in healthy controls. Schizophrenia patients showed smaller GMV than healthy controls in brain regions located in the bilateral limbic system, bilateral parietal lobe, bilateral insula, bilateral primary auditory cortex, left frontal lobe, and bilateral occipital regions. In a conjunction analysis, GMV in the left midcingulate cortex (MCC) appears negatively correlated to NGF serum levels in the group of schizophrenia patients and also to be reduced compared to healthy controls. These results suggest an increased vulnerability of schizophrenia patients to changes in NGF levels compared to healthy controls and support a role for NGF signaling in the pathophysiology of schizophrenia. As our pilot study is exploratory in nature, further studies enrolling larger sample sizes will be needed to further corroborate our findings and to investigate the influence of additional covariates.