Association between psoriasis and dementia: A systematic review

Gentiopicrin-Loaded Chitosan Nanoparticles as a Topical Agent for the Treatment of Psoriasis

Psoriasis, a chronic inflammatory skin disease induced by various factors, including genetic factors, immune factors, environmental factors, and psychological factors, is characterized by thickening of the epidermis, excessive proliferation of keratinocytes, abnormal differentiation, and an excessive inflammatory response. Traditional treatments for psoriasis still face challenges because of limited curative effects, notable side effects, and a tendency for recurrence. In contrast, topical therapy provides a favorable option for psoriasis treatment because of its noninvasive and self-administered method. In this study, gentiopicrin (Gen) is encapsulated in the liposomes to form a nanodrug, and then chitosan is covered on the nanodrug to assemble the nanodrug delivery system (CS@Gen), which is used as a topical agent for treating psoriasis. Then M5 (a mixture of five pro-inflammatory cytokines, i.e., IL-17A, IL-22, IL-1α, oncostatin M, and TNF-α)-induced HacaT cells and imiquimod-induced psoriasis mouse models are established, whose results show that CS@Gen induces apoptosis and inhibits the proliferation and cell migration of psoriasis keratinocytes. Additionally, the application of CS@Gen cream can significantly reduce epidermal thickness, diminish skin scaling, and improve other related mechanisms in mice affected by psoriasis. Meanwhile, the prepared CS@Gen can significantly reduce the expression levels of IL-17a, Cxcl2, S100a, Mki67, and other related inflammatory factors, resulting in indirectly inhibiting the inflammation of keratinocytes. In summary, the present study provides an ideal loading for an anti-inflammatory and immunomodulatory drug delivery system for the treatment of psoriasis.

Hospital-Diagnosed Infections, Autoimmune Diseases, and Subsequent Dementia Incidence

Importance

Systemic inflammation has been suggested to explain reported associations between infections and dementia. Associations between autoimmune diseases and dementia also suggest a role for peripheral systemic inflammation.

Objective

To investigate the associations of infections and autoimmune diseases with subsequent dementia incidence and to explore potential shared signals presented by the immune system in the 2 conditions.

Design, Setting, and Participants

This nationwide, population-based, registry-based cohort study was conducted between 1978 and 2018 (40-year study period). All Danish residents born 1928 to 1953, alive and in Denmark on January 1, 1978, and at age 65 years were included. Persons with prior registered dementia and those with HIV infections were excluded. Data were analyzed between May 2022 and January 2023.

Exposures

Hospital-diagnosed infections and autoimmune diseases.

Main Outcomes and Measures

All-cause dementia, defined as the date of a first registered dementia diagnosis after age 65 years in the registries. Poisson regression with person-years at risk as an offset variable was used to analyze time to first dementia diagnosis.

Results

A total of 1 493 896 individuals (763 987 women [51%]) were followed for 14 093 303 person-years (677 147 [45%] with infections, 127 721 [9%] with autoimmune diseases, and 75 543 [5%] with dementia). Among individuals with infections, 343 504 (51%) were men, whereas among those with autoimmune diseases, 77 466 (61%) were women. The dementia incidence rate ratio (IRR) following any infection was 1.49 (95% CI, 1.47-1.52) and increased along with increasing numbers of infections in a dose-dependent manner. Dementia rates were increased for all infection sites in the short term, but not always in the long term. The dementia IRR following any autoimmune disease was 1.04 (95% CI, 1.01-1.06), but no dose-dependent increase was observed, and only a few autoimmune conditions showed increased IRRs for dementia.

Conclusions and Relevance

These findings may point toward a role for infection-specific processes in the development of dementia, rather than general systemic inflammation, as previously hypothesized. Assessing these 2 conditions in a single setting may allow for additional insights into their roles in dementia and for hypotheses on possible underlying mechanisms.

Association Between Psoriasis and Dementia: A Retrospective Cohort Study

Background

To date, no large study has examined the relationship between psoriasis and dementia in Germany.

Objective

The aim of this study was to assess the association between psoriasis and the risk of all-cause dementia in patients followed in general practices in Germany.

Methods

This retrospective cohort study is based on longitudinal data from the IQVIA^TM Disease Analyzer database and included patients with an initial diagnosis of psoriasis between January 1995 and December 2014 in 1,173 general practices in Germany. Patients without psoriasis were matched individually (1:1) to psoriasis patients using propensity scores. The main outcome of the study was the cumulative incidence of dementia diagnoses within up to 15 years of the index date. Univariate Cox proportional regression models were used to assess the relationship between psoriasis or psoriatic arthritis and dementia.

Results

The present study included 10,583 patients with a diagnosis of psoriasis and 10,583 controls without psoriasis. After 15 years of follow-up, 22.0% of the psoriasis patients and 19.1% (p < 0.001) of the non-psoriasis patients developed dementia. The incidence rate of dementia in 1,000 person-years was 15.0 in psoriasis patients and 11.9 in the non-psoriasis cohort. Psoriasis was significantly associated with a dementia risk (HR: 1.24; 95% CI: (1.14-1.35); p < 0.001). The association was stronger in patients with PsA (HR: 1.35; 95% CI: (0.98-1.86)) but this was not significant (p = 0.070).

Conclusion

The present study found a positive association between psoriasis and all-cause dementia in patients in general practices in Germany.

Psoriasis and neurodegenerative diseases—a review

Psoriasis is a chronic skin disease with underlying genetic, inflammatory and immunological background, which is a great medical problem, currently regarded as a systemic condition. Neurodegenerative diseases (NDs) are characterized by a progressive loss of nervous tissue, which affects elderly people more frequently; therefore, it is suspected that, due to society's aging, morbidity is going to increase. We performed a thorough review in order to investigate for the first time whether psoriasis may predispose to different particular neurodegenerative diseases—Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS). PubMed search resulted in the retrieval of 833 records, of which 77 eligible were included in the review. Our thorough analysis revealed there are some potential links between psoriasis and NDs (inflammation, oxidative stress, genetics, cardiometabolic disorders), but there is no strong evidence that psoriasis may predispose to NDs. Based on the evidence, it seems that the risk of PD in psoriatics is not increased, and the evidence for increased risk of AD slightly prevails the data that state the opposite. ALS risk does not seem to be increased in psoriatics. The paucity of original studies does not allow for the formulation of definitive conclusions but encourages to perform further investigations.

Neuroinflammation in Dementia—Therapeutic Directions in a COVID-19 Pandemic Setting

Although dementia is a heterogenous group of diseases, inflammation has been shown to play a central role in all of them and provides a common link in their pathology. This review aims to highlight the importance of immune response in the most common types of dementia. We describe molecular aspects of pro-inflammatory signaling and sources of inflammatory activation in the human organism, including a novel infectious agent, SARS-CoV-2. The role of glial cells in neuroinflammation, as well as potential therapeutic approaches, are then discussed. Peripheral immune response and increased cytokine production, including an early surge in TNF and IL-1β concentrations activate glia, leading to aggravation of neuroinflammation and dysfunction of neurons during COVID-19. Lifestyle factors, such as diet, have a large impact on future cognitive outcomes and should be included as a crucial intervention in dementia prevention. While the use of NSAIDs is not recommended due to inconclusive results on their efficacy and risk of side effects, the studies focused on the use of TNF antagonists as the more specific target in neuroinflammation are still very limited. It is still unknown, to what degree neuroinflammation resulting from COVID-19 may affect neurodegenerative process and cognitive functioning in the long term with ongoing reports of chronic post-COVID complications.