B-cell depletion in autoimmune diseases

B cells have a pivotal function in the pathogenesis of autoimmune diseases, such as rheumatoid arthritis, multiple sclerosis and systemic lupus erythematosus. In autoimmune disease, B cells orchestrate antigen presentation, cytokine production and autoantibody production, the latter via their differentiation into antibody-secreting plasmablasts and plasma cells. This article addresses the current therapeutic strategies to deplete B cells in order to ameliorate or potentially even cure autoimmune disease. It addresses the main target antigens in the B-cell lineage that are used for therapeutic approaches. Furthermore, it summarises the current evidence for successful treatment of autoimmune disease with monoclonal antibodies targeting B cells and the limitations and challenges of these approaches. Finally, the concept of deep B-cell depletion and immunological reset by chimeric antigen receptor T cells is discussed, as well as the lessons from this approach for better understanding the role of B cells in autoimmune disease.

The Impact of Tobacco Smoking on Systemic Sclerosis, Idiopathic Inflammatory Myositis, and Systemic Lupus Erythematosus

This narrative review aims specifically to explore the relationship between tobacco exposure and systemic sclerosis (SSc), idiopathic inflammatory myositis (IIM), and systemic lupus erythematosus (SLE). Relevant articles were obtained by searching key terms such as "tobacco," "smoking," "scleroderma," "myositis," "lupus," and "Sjögren's" in PubMed and Google Scholar databases. The selected articles ranged from the years 2010 to 2023. Inclusion criteria were based on the relevance and contribution to the field of study. Systemic sclerosis is a complex condition involving multiple immune cell lines that can be influenced by tobacco. However, the existing literature does not provide sufficient evidence to support an increased risk of SSc in smokers or the impact on treatment options. Cigarette smoking does increase the risk of skin ulcerations in SSc patients. In addition, cigarette smoking has been associated with IIM through genetic and molecular mechanisms. Smokers with dermatomyositis or polymyositis are at an elevated risk of atherosclerosis and interstitial lung disease. Similarly, smoking in patients with SLE increases the risk of organ damage, thrombosis, and disease severity compared with non-smokers. Smokers with SLE also have more difficulty in controlling disease flares compared with non-smokers. Tobacco exposure can lead to secondary complications in patients with IIM and SLE, although the course of treatment may not differ significantly. No definitive conclusions can be drawn to the clear relationship between tobacco smoking and Sjögren's's syndrome.

Antimalarial Drugs at the Intersection of SARS-CoV-2 and Rheumatic Diseases: What Are the Potential Opportunities?

Background and Objectives: The coronavirus disease of 2019 (COVID-19) pandemic has posed a serious threat to humanity and is considered a global health emergency. Antimalarial drugs (ADs) have been used in the treatment of immuno-inflammatory arthritis (IIA) and coronavirus infection (COVID-19). The aim of this review is to analyze the current knowledge about the immunomodulatory and antiviral mechanisms of action, characteristics of use, and side effects of antimalarial drugs. Material and Methods: A literature search was carried out using PubMed, MEDLINE, SCOPUS, and Google Scholar databases. The inclusion criteria were the results of randomized and cohort studies, meta-analyses, systematic reviews, and original full-text manuscripts in the English language containing statistically confirmed conclusions. The exclusion criteria were summary reports, newspaper articles, and personal messages. Qualitative methods were used for theoretical knowledge on antimalarial drug usage in AIRDs and SARS-CoV-2 such as a summarization of the literature and a comparison of the treatment methods. Results: The ADs were considered a "candidate" for the therapy of a new coronavirus infection due to mechanisms of antiviral activity, such as interactions with endocytic pathways, the prevention of glycosylation of the ACE2 receptors, blocking sialic acid receptors, and reducing the manifestations of cytokine storms. The majority of clinical trials suggest no role of antimalarial drugs in COVID-19 treatment or prevention. These circumstances do not allow for their use in the treatment and prevention of COVID-19. Conclusions: The mechanisms of hydroxychloroquine are related to potential cardiotoxic manifestations and demonstrate potential adverse effects when used for COVID-19. Furthermore, the need for high doses in the treatment of viral infections increases the likelihood of gastrointestinal side effects, the prolongation of QT, and retinopathy. Large randomized clinical trials (RCTs) have refuted the fact that there is a positive effect on the course and results of COVID-19.

Emerging Medical Therapies in Rosacea: A Narrative Review

Rosacea is a chronic inflammatory disease with a multifactorial pathogenesis. The wide spectrum of clinical phenotypes, including erythema, telangiectasia, inflammatory papules and pustules, and phyma, demand an individualized approach to treatment. This narrative review offers an updated reference for rosacea management by covering the latest developments in both topical and systemic treatments, including data from newly approved therapies, updates to current treatment modalities and ongoing clinical trials. Although use of benzoyl peroxide as a treatment for rosacea has typically been limited due to irritation, the improved tolerability due to microencapsulation of benzoyl peroxide 5% cream provides a new therapeutic option for patients with rosacea. Minocycline foam and topical ivermectin cream add to our armamentarium of treatment options, particularly for inflammatory papules and pustules. Sarecycline has a narrower spectrum of antibacterial activity, which might reduce the development of antibiotic resistance and disruption of the microbiome compared to other oral antibiotics. Brimonidine gel and oxymetazoline cream provide topical options for redness and flushing. There is emerging evidence about the role of hydroxychloroquine and intradermal botulinum toxin A, which may improve rosacea through their effects on mast cells. The clinical trials pipeline includes agents with a variety of mechanisms, including mast cell stabilization, antimicrobial, anti-inflammatory, and vasoconstrictive effects. However, the clinical pipeline for rosacea appears limited, and there remain important unmet needs for patients with more recalcitrant rosacea or phymatous disease. In addition, there is a need for comparative effectiveness studies to identify the highest value treatment approaches for patients with rosacea.

Current Treatment Approach, Emerging Therapies and New Horizons in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE), the prototype of systemic autoimmune diseases is characterized by extreme heterogeneity with a variable clinical course. Renal involvement may be observed and affects the outcome. Hydroxychloroquine should be administered to every lupus patient irrespective of organ involvement. Conventional immunosuppressive therapy includes corticosteroids, methotrexate, cyclophosphamide, mycophenolate mofetil, azathioprine, cyclosporine and tacrolimus. However, despite conventional immunosuppressive treatment, flares occur and broad immunosuppression is accompanied by multiple side effects. Flare occurrence, target organ involvement, side effects of broad immunosuppression and increased knowledge of the pathogenetic mechanisms involved in SLE pathogenesis as well as the availability of biologic agents has led to the application of biologic agents in SLE management. Biologic agents targeting various pathogenetic paths have been applied. B cell targeting agents have been used successfully. Belimumab, a B cell targeting agent, has been approved for the treatment of SLE. Rituximab, an anti-CD20 targeting agent is also used in SLE. Anifrolumab, an interferon I receptor-targeting agent has beneficial effects on SLE. In conclusion, biologic treatment is applied in SLE and should be further evaluated with the aim of a good treatment response and a significant improvement in quality of life.

An Overview of Repurposed Drugs for Potential COVID-19 Treatment

The COVID-19 pandemic caused by SARS-CoV-2 has placed severe constraints on healthcare systems around the globe. The SARS-CoV-2 virus has caused upheaval in the healthcare and economic sectors worldwide. On the 20th of May 2020, the World Health Organisation declared COVID-19 a global pandemic due to the unprecedented number of cases reported around the globe. As of the 4th of November 2022, there were 637,117,429 coronavirus cases reported globally by Worldometer stats, with 6,602,572 related deaths. In South Africa, there were approximately 4,029,496 coronavirus cases and 102,311 associated deaths. As such, there is a need for efficacious therapeutic regimes. There has been a paucity of knowledge encompassing the use of effective and specific antiviral drug therapies for treating COVID-19 since the outbreak. In this review, we provide valuable insights into the repurposing of current drugs for COVID-19. Drug repurposing provides a suitable option for the discovery of efficacious drugs for COVID-19, thereby decreasing the costs and turnaround times of drug development strategies. This review provides an overview of ten drugs, including antimalarial, antiparasitic, anti-inflammatory, nucleoside analogue, monoclonal-antibody drugs, that were repurposed for the potential treatment of COVID-19.

Inhibiting TLR7 Expression in the Retinal Pigment Epithelium Suppresses Experimental Autoimmune Uveitis

Experimental autoimmune uveitis (EAU), a model of human uveitis, is an organ-specific, T cell-mediated autoimmune disease. Autoreactive T cells can penetrate the blood-retinal barrier, which is a physical defense composed of tight junction-linked retinal pigment epithelial (RPE) cells. RPE cells serve as antigen-presenting cells (APCs) in the eye since they express MHC class I and II and Toll-like receptors (TLRs). Although previous studies have shown that supplementation with TLR agonists exacerbates uveitis, little is known about how TLR signaling in the RPE contributes to the development of uveitis. In this study, we isolated the RPE from EAU mice, which were induced by active immunization (aEAU) or adoptive transfer of antigen-specific T cells (tEAU). The expression of TLRs on RPE was determined, and both aEAU and tEAU mice exhibited induced tlr7 expression. The TLR7 agonist R848 was shown to induce aggressive disease progression, along with significantly elevated levels of the uveopathogenic cytokine IL-17. Furthermore, not only IL-17 but also R848 appeared to enhance the inflammatory response and to impair the barrier function of the RPE, indicating that TLR7 signaling is involved in the pathogenesis of EAU by affecting the behaviors of the RPE and consequently allowing the infiltration of autoreactive T cells intraocularly. Finally, local application of shRNA against TLR7 delivered by recombinant AAV effectively inhibited disease severity and reduced IFN-γ and IL-17. Our findings highlight an immunomodulatory role of RPE TLR7 in EAU development and provide a potential therapeutic strategy for autoimmune uveitis.

Association between Hydroxychloroquine and bacterial pneumonia in rheumatic patients: A population-based propensity score matching cohort study

BACKGROUND

Whether hydroxychloroquine (HCQ) use could reduce lesser risk of bacterial infections is unknown. We aimed to conduct a retrospective cohort propensity-matching study to investigate the association between HCQ use and the incidence of bacterial pneumonia in rheumatic patients.

METHODS

The Longitudinal Health Insurance Database (LHID) from Taiwan National Health Insurance Research Database (NHIRD) of 23 million Taiwanese populations was used. We included patients who were newly diagnosed with rheumatic and immune disease (ICD-9-CM codes 696.0, 710, 714) within 2000-2012. HCQ users and non-users were then matched according to age, sex, urbanisation level, monthly income, comorbidities and medications in the ratio of 1:1 by the propensity score matching. Cox proportional hazard model was used to evaluate the risk of bacterial pneumonia in rheumatic patients who used HCQ and who did not use HCQ.

RESULTS

There were total 3285 patients with rheumatic and immune disease enrolled. The cumulative incidence curve of patients with the use of HCQ sulphate had no difference to that of patient without the use of HCQ sulphate in propensity score-matched cohort, (Log-rank test: P = .5). However, patients who used HCQ sulphate for more than 1400 average use days had a lesser risk of bacterial pneumonia (adjusted HR = 0.55, 95% CI = 0.35, 0.89) in the cohort matched, with regarding HCQ non-users as a reference.

CONCLUSION

Rheumatic patients taking HCQ had no overall significant differences of bacterial pneumonia incidences compared with rheumatic patients not taking HCQ. HCQ used more than >1400 days or lupus patients using HCQ was associated with lower risk of bacterial pneumonia.

Nanoparticles as an effective drug delivery system in COVID-19

BACKGROUND

The global healthcare sector has been dealing with a situation known as a novel severe acute respiratory syndrome (SARS-CoV-2) since the end of 2019. Covid-19 is an acronym for Covid-19 (Coronavirus Disease- 2019). It causes a respiratory infection that includes cold, sneezing and coughing, and pneumonia. In the case of an animal, it causes diarrhea and upper respiratory diseases. Covid-19 transmitted human to human via airborne droplets. First Covid-19 emerged in Wuhan market China and it spread rapidly throughout the World. As we know nanoparticles are a novel drug delivery system. They have various advantageous effects like increasing the efficacy of the drug, safety, etc. In this review, we study about the nanoparticles and summarize how it is effective during drug delivery system in Covid-19. Chitosan is a much focused biopolymeric nanoparticle. It delivers drugs to the specific target site. In a recent health crisis, chitosan nanoparticles are one of the ways to release drugs of Covid-19, and specifically in the lungs of the affected patients. We studied and extracted our data from various research papers, review papers, and some other articles.

OBJECTIVE

The main goal is to study the nanoparticles and their future aspects which is an effective drug delivery system in Covid-19.

METHODS

The bibliographic search was done through a systematic search. The terms "Nanoparticles", "Covid-19 ", "Drug delivery" etc. were used to search the databases/search engines like "Google Scholar", "NCBI", "PubMed", "Science Direct" etc. These databases and search engines used here perform the limited criteria of search to conduct a systematic literature survey for the study and report writing. All the text from the articles and research papers were studied and analyzed. The various articles and research papers were used in writing this report and all of which are mentioned in the reference section of this report.

CONCLUSION

Our current studies reveal that nanoparticles may prove very helpful in the delivery of drugs for Covid-19 treatment. Many cases showed that patients, where drugs are delivered with the help of nanoparticles, produced very few side effects.

NHE6 depletion corrects ApoE4-mediated synaptic impairments and reduces amyloid plaque load

Apolipoprotein E4 (ApoE4) is the most important and prevalent risk factor for late-onset Alzheimer’s disease (AD). The isoelectric point of ApoE4 matches the pH of the early endosome (EE), causing its delayed dissociation from ApoE receptors and hence impaired endolysosomal trafficking, disruption of synaptic homeostasis, and reduced amyloid clearance. We have shown that enhancing endosomal acidification by inhibiting the EE-specific sodium-hydrogen exchanger 6 (NHE6) restores vesicular trafficking and normalizes synaptic homeostasis. Remarkably and unexpectedly, loss of NHE6 (encoded by the gene Slc9a6) in mice effectively suppressed amyloid deposition even in the absence of ApoE4, suggesting that accelerated acidification of EEs caused by the absence of NHE6 occludes the effect of ApoE on amyloid plaque formation. NHE6 suppression or inhibition may thus be a universal, ApoE-independent approach to prevent amyloid buildup in the brain. These findings suggest a novel therapeutic approach for the prevention of AD by which partial NHE6 inhibition reverses the ApoE4-induced endolysosomal trafficking defect and reduces plaque load.

Mast Cell Stabilizers in the Treatment of Rosacea: A Review of Existing and Emerging Therapies

Rosacea is a chronic inflammatory skin disease characterized by centrofacial erythema, papules, pustules, and telangiectasias. The onset of rosacea typically occurs after 30 years of age. It is estimated that approximately 2–5% of adults worldwide are affected. While the exact etiology of rosacea remains unknown, its pathogenesis is thought to be multifactorial with both environmental and genetic factors implicated. Ultraviolet radiation, heat, steam, ingested agents, including spicy foods and alcohol, host vasculature, dermal matrix degeneration, genetic susceptibility, and microbial organisms, including Demodex mites and Heliobacter pylori, have been implicated in the development of rosacea. Recently, mast cells (MCs) have emerged as key players in the pathogenesis of rosacea through the release of pro-inflammatory cytokines, chemokines, proteases, and antimicrobial peptides leading to cutaneous vasodilation, angiogenesis, and tissue fibrosis. Several existing and emerging topical, oral, and injectable therapeutics have been associated with improvement of rosacea symptoms based on their ability to stabilize and downregulate activated MCs. Herein, we review the data implicating MCs in the pathogenesis of rosacea and discuss interventions that may stabilize this pathway.

Green Composite Sensor for Monitoring Hydroxychloroquine in Different Water Matrix

Hydroxychloroquine (HCQ), a derivative of 4-aminoquinolone, is prescribed as an antimalarial prevention drug and to treat diseases such as rheumatoid arthritis, and systemic lupus erythematosus. Recently, Coronavirus (COVID-19) treatment was authorized by national and international medical organizations by chloroquine and hydroxychloroquine in certain hospitalized patients. However, it is considered as an unproven hypothesis for treating COVID-19 which even itself must be investigated. Consequently, the high risk of natural water contamination due to the large production and utilization of HCQ is a key issue to overcome urgently. In fact, in Brazil, the COVID-19 kit (hydroxychloroquine and/or ivermectin) has been indicated as pre-treatment, and consequently, several people have used these drugs, for longer periods, converting them in emerging water pollutants when these are excreted and released to aquatic environments. For this reason, the development of tools for monitoring HCQ concentration in water and the treatment of polluted effluents is needed to minimize its hazardous effects. Then, in this study, an electrochemical measuring device for its environmental application on HCQ control was developed. A raw cork–graphite electrochemical sensor was prepared and a simple differential pulse voltammetric (DPV) method was used for the quantitative determination of HCQ. Results indicated that the electrochemical device exhibited a clear current response, allowing one to quantify the analyte in the 5–65 µM range. The effectiveness of the electrochemical sensor was tested in different water matrices (in synthetic and real) and lower HCQ concentrations were detected. When comparing electrochemical determinations and spectrophotometric measurements, no significant differences were observed (mean accuracy 3.0%), highlighting the potential use of this sensor in different environmental applications.

Hydroxychloroquine alleviates the neurotoxicity induced by anti-ribosomal P antibodies

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by a wide spectrum of autoantibodies, among which anti-ribosomal P (anti-P) antibodies are considered to be closely related to the neuropsychiatric SLE (NPSLE). Hydroxychloroquine (HCQ) has been proven to be effective against a variety of autoimmune diseases and is an essential drug for the treatment of SLE. In this study, we investigated the effects of anti-ribosomal P (anti-P) antibodies on neural cells and determined whether hydroxychloroquine (HCQ) influenced the anti-P antibodies-induced changes. The results showed that the binding of anti-P antibodies with mouse neuroblastoma- 2a (N2a) cells and rat primary neurons resulted in elevated intracellular calcium levels, inducing decreased cell viability and cell apoptosis. These inhibitory effects were alleviated by HCQ in a concentration-dependent manner by reducing the intracellular calcium levels and modulating the expression of apoptotic proteins. In summary, our study demonstrates that anti-P antibodies induce neural cell damage. HCQ could ease the damage effects and may play a neuroprotective role in NPSLE.

Therapeutic Agents for COVID-19: an Overview

Background::

The pathological agent of Coronavirus disease 2019 (COVID-19) is a novel coronavirus termed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). COVID-19 has its origin in Wuhan, China, and spread to other provinces of China and subsequently to other countries resulting in a pandemic worldwide. The virus is extremely contagious and causes pneumonia and respiratory failure. Since its emergence, researchers around the world are trying to develop vaccines and find suitable drugs for the treatment of COVID-19.

Objective::

To give an overview of the various therapeutic agents for COVID-19 such as vaccines and drugs that are in preclinical stage or under different stages of clinical trials.

Results::

As per World Health Organization (WHO), there are 137 vaccines under development to date, out of which few vaccines have successfully completed preclinical studies and reached clinical trials. According to the present scenario, only one coronavirus vaccine (sputnik-V) has been approved by the Ministry of Health of the Russian Federation. Till date, there are no United States Food and Drug Administration (USFDA) approved drugs to treat COVID-19 patients. However, depending on patient’s condition, different drugs such as antiviral agents like Remdesivir, antimalarial drugs like Hydroxychloroquine, antibiotics like Azithromycin and corticosteroids like Dexamethasone are being applied and some of them have proved to be effective up to a certain extent.

Conclusion::

Although several vaccines for COVID-19 are under development and various drugs have been tried for its treatment, an ideal drug candidate or a vaccine is still lacking. Almost all the big pharmaceutical companies are associated with one or more research initiatives in order to develop vaccines and drugs. Many of them are going through clinical stages, expecting a positive outcome by the end of 2020.

Emerging Technologies for the Treatment of COVID-19

The new coronavirus, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), turned into a pandemic affecting more than 200 countries. Due to the high rate of transmission and mortality, finding specific and effective treatment options for this infection is currently of urgent importance. Emerging technologies have created a promising platform for developing novel treatment options for various viral diseases such as the SARS-CoV-2 virus. Here, we have described potential novel therapeutic options based on the structure and pathophysiological mechanism of the SARS-CoV-2 virus, as well as the results of previous studies on similar viruses such as SARS and MERS. Many of these approaches can be used for controlling viral infection by reducing the viral damage or by increasing the potency of the host response. Owing to their high sensitivity, specificity, and reproducibility, siRNAs, aptamers, nanobodies, neutralizing antibodies, and different types of peptides can be used for interference with viral replication or for blocking internalization. Receptor agonists and interferon-inducing agents are also potential options to balance and enhance the innate immune response against SARS-CoV-2. Solid evidence on the efficacy and safety of such novel technologies is yet to be established although many well-designed clinical trials are underway to address these issues.

Molecular effects and retinopathy induced by hydroxychloroquine during SARS-CoV-2 therapy: Role of CYP450 isoforms and epigenetic modulations

Antimalaria drugs such as chloroquine (CQ) and hydroxychloroquine (HCQ) have been administered to several inflammatory diseases including rheumatoid arthritis and systemic lupus erythematosus, and infectious diseases such as acquired immune deficiency syndrome and influenza. Recently, several patients infected with novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were given HCQ, and showed a discrepant response. HCQ inhibits SARS-CoV-2 cell entry, and inflammatory cascade by interfering with lysosomal and endosomal activities, and autophagy, impeding virus-membrane fusion, and inhibiting cytokine production resulted from inflammatory pathways activation. Despite ongoing administration of HCQ in a wide spectrum of disorders, there are some reports about several side effects, especially retinopathy in some patients treated with HCQ. Cytochrome P450 (CYP450) and its isoforms are the main metabolizers of HCQ and CQ. Pharmacokinetic properties of CYP enzymes are influenced by CYP polymorphism, non-coding RNAs, and epigenetic mechanisms such as DNA methylation, and histone acetylation. Accumulating evidence about side effects of HCQ in some patients raise the possibility that different response of patients to HCQ might be due to difference in their genome. Therefore, CYP450 genotyping especially for CYP2D6 might be helpful to refine HCQ dosage. Also, regular control of retina should be considered for patients under HCQ treatment. The major focus of the present review is to discuss about the pharmacokinetic and pharmacodynamic properties of CQ and HCQ that may be influenced by epigenetic mechanisms, and consequently cause several side effects especially retinopathy during SARS-CoV-2 therapy.

Available Compounds With Therapeutic Potential Against COVID-19: Antimicrobial Therapies, Supportive Care, and Probable Vaccines

The recent outbreak of the COVID-2019 (coronavirus disease 2019) due to the infectious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has realized the requirement of alternative therapeutics to mitigate and alleviate this lethal infection. These alternative therapies are effective when they are started at the initial stage of the infection. Some drugs that were used in previous other related infections SARS-CoV-2003 and Middle East respiratory syndrome coronavirus (MERS-CoV)-2012 could be potentially active against currently emerging SARS-CoV-2. This fact imparts some rationale of current interventions, in the absence of any specific therapeutics for SARS-CoV-2. It is imperative to focus on the available antimicrobial and adjunct therapies during the current emergency state and overcome the challenges associated with the absence of robust controlled studies. There is no established set of drugs to manage SARS-CoV-2 infected patients. However, closely following patients’ conditions and responding with the dosage guidelines of available drugs may significantly impact our ability to slow down the infection. Of note, it depends upon the condition of the patients and associated comorbid; therefore, the health workers need to choose the drug combinations judiciously until COVID-19 specific drug or vaccine is developed with the collective scientific rigor. In this article, we reviewed the available antimicrobial drug, supportive therapies, and probable high importance vaccines for the COVID-19 treatment.

Impact of Hydroxychloroquine/Chloroquine in COVID-19 Therapy: Two Sides of the Coin

Coronavirus disease 2019 (COVID-19), which is caused by a novel severe acute respiratory syndrome coronavirus (SARS-CoV-2), has recently emerged as a global health threat. To address this health emergency, various therapeutic approaches are currently under investigation. There is limited evidence on the effectiveness of hydroxychloroquine (HCQ) and chloroquine (CQ) as COVID-19 therapies, and thus World Health Organization (WHO) mentioned that "Current data shows that this drug does not reduce deaths among hospitalized COVID-19 patients, nor help people with mild or moderate disease." CQ and HCQ are typically used for the treatment of malaria but have been recognized for certain beneficial effects in COVID-19 patients based on some clinical outcomes from the clinical treatment of COVID-19. A standard dose of HCQ has been proven effective and less toxic than CQ in COVID-19 patients; however, a comprehensive understanding of a patient's clinical condition is necessary. Based on several hospital findings, the Food and Drug Administration (FDA) has officially cancelled the emergency use authorization for HCQ and CQ for treating hospitalized COVID-19 patients on June 15, 2020. In this review, we highlight both pros and cons of the clinical use of CQ and HCQ in COVID-19 patients.

A Review on Current Repurposing Drugs for the Treatment of COVID-19: Reality and Challenges

The coronavirus disease 2019 (COVID-19) caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global pandemic with a high growth rate of confirmed cases. Therefore, therapeutic options are desperately urgent to fight with this damning virus. As it may take years to develop a specific therapy of COVID-19, it is urgent to emphasize the repurposing of drugs used for other conditions. This study reviewed the most common drugs for COVID-19 based on available online literature representing the latest in vitro clinical trial database, rational of use, adverse effects, potential toxicities, and US National Institute of Health (NIH) recommendation to use for COVID-19. Based on the preliminary data from clinical trials and considering the NIH and FDA recommendation, remdesivir and convalescent blood products are the most promising potential for COVID-19 treatment. The use of chloroquine, hydroxychloroquine, favipiravir, ivermectin, and colchicine might also be effective. However, furthermore, in vivo investigations are needed in detail individually and in combination for possible benefits in humans. Besides, tocilizumab might be deemed as adjunctive therapy for patients with cytokine release syndrome. However, lopinavir-ritonavir, anakinra, and sarilumab had not proven their clinical efficacy. Eventually, sarilumab has been withdrawn from sponsored clinical trials based on the preliminary data. Baricitinib and ruxolitinib have the additive immunosuppressive effect. Consequently, all of these drugs are being evaluated with further studies. In addition, drug-drug interaction and safety concerns must be taken into account before the administration of the recommended drugs.

Agonist and antagonist ligands of toll-like receptors 7 and 8: Ingenious tools for therapeutic purposes

The discovery of the TLRs family and more precisely its functions opened a variety of gates to modulate immunological host responses. TLRs 7/8 are located in the endosomal compartment and activate a specific signaling pathway in a MyD88-dependant manner. According to their involvement into various autoimmune, inflammatory and malignant diseases, researchers have designed diverse TLRs 7/8 ligands able to boost or block the inherent signal transduction. These modulators are often small synthetic compounds and most act as agonists and to a much lesser extent as antagonists. Some of them have reached preclinical and clinical trials, and only one has been approved by the FDA and EMA, imiquimod. The key to the success of these modulators probably lies in their combination with other therapies as recently demonstrated. We gather in this review more than 360 scientific publications, reviews and patents, relating the extensive work carried out by researchers on the design of TLRs 7/8 modulators, which are classified firstly by their biological activities (agonist or antagonist) and then by their chemical structures, which total syntheses are not discussed here. This review also reports about 90 clinical cases, thereby showing the biological interest of these modulators in multiple pathologies.

Hydroxychloroquine is a novel therapeutic approach for rosacea

Rosacea is a chronic inflammatory disease in face. Hydroxychloroquine (HCQ), an anti-malaria drug, was reported to have anti-inflammation activities. However, the role of HCQ on rosacea remains unclear. In this study, we revealed the potential molecular mechanism by which HCQ improved rosacea in rosacea-like mice and mast cells (MCs). Moreover, the effects of HCQ treatment for rosacea patients were investigated. In this study, we found HCQ ameliorated the rosacea-like phenotype and MCs infiltration. The elevated pro-inflammatory factors and mast cell protease were significantly inhibited by HCQ treatment in rosacea-like mice. In vitro, HCQ suppresses LL37-induced MCs activation in vitro, including the release of inflammatory factors, chemotaxis, degranulation and calcium influx. Moreover, HCQ attenuated LL37-mediated MCs activation partly via inhibiting KCa3.1-mediated calcium signaling. Thus, these evidences suggest HCQ ameliorated rosacea-like dermatitis may be by regulating immune response of MCs. Finally, the 8-week HCQ treatment exerted satisfactory therapeutic effects on erythema and inflammatory lesions of rosacea patients, indicating that it is a promising drug for rosacea in clinical treatment.

Hydroxychloroquine retinopathy - implications of research advances for rheumatology care

Despite advances in therapy for rheumatic diseases, hydroxychloroquine remains almost universally recommended for the treatment of systemic lupus erythematosus (SLE), and is often used in the management of other rheumatic diseases such as rheumatoid arthritis (RA). However, the major dose-limiting toxicity of hydroxychloroquine is retinopathy that can lead to loss of vision. New highly sensitive screening methods can identify early stages of retinopathy, and studies that include these modalities have indicated a substantially higher prevalence of hydroxychloroquine retinopathy than was previously recognized, resulting in revisions to ophthalmology guidelines and the recommendation of a low dose of hydroxychloroquine for many patients. However, the efficacy of low-dose hydroxychloroquine for treating SLE and other rheumatic diseases is unknown. Further studies are required to establish the effectiveness and retinal safety of the latest hydroxychloroquine treatment recommendations.

The non-haemostatic role of platelets in systemic lupus erythematosus

Dysregulation of lymphocyte function, accumulation of autoantibodies and defective clearance of circulating immune complexes and apoptotic cells are hallmarks of systemic lupus erythematosus (SLE). Moreover, it is now evident that an intricate interplay between the adaptive and innate immune systems contributes to the pathogenesis of SLE, ultimately resulting in chronic inflammation and organ damage. Platelets circulate in the blood and are chiefly recognized for their role in the prevention of bleeding and promotion of haemostasis; however, accumulating evidence points to a role for platelets in both adaptive and innate immunity. Through a broad repertoire of receptors, platelets respond promptly to immune complexes, complement and damage-associated molecular patterns, and represent a major reservoir of immunomodulatory molecules in the circulation. Furthermore, evidence suggests that platelets are activated in patients with SLE, and that they could contribute to the circulatory autoantigenic load through the release of microparticles and mitochondrial antigens. Herein, we highlight how platelets contribute to the immune response and review evidence implicating platelets in the pathogenesis of SLE.

Examination of novel 4-aminoquinoline derivatives designed and synthesized by a hybrid pharmacophore approach to enhance their anticancer activities

In an attempt to develop effective and potentially safe anticancer agents, thirty-six 4-aminoquinoline derived sulfonyl analogs were designed and synthesized using a hybrid pharmacophore approach. The cytotoxicity of these compounds was determined using three breast tumor cell lines (MDA-MB231, MDA-MB468 and MCF7) and two matching non-cancer breast epithelial cell lines (184B5 and MCF10A). Although most of the compounds were quite effective on the breast cancer cells, the compound 7-chloro-4-(4-(2,4-dinitrophenylsulfonyl)piperazin-1-yl)quinoline (13; VR23) emerged as potentially the most desirable one in this series of compounds. Data from the NCI-60 cancer panel screening show that compound 13 is effective on a wide range of different cancers. Importantly, compound 13 is needed up to 17.6-fold less doses to achieve the same IC₅₀ against cancer than non-cancer cells (MDA-MB468 vs MCF10A), suggesting that it can potentially be less toxic to normal cells. Cancer cells formed multiple centrosomes in the presence of compound 13, resulting in the cell cycle arrest at prometa-meta phase. This abnormality leads to eventual cell demise with sub-G1 DNA content typically shown with apoptotic cells. In addition, compound 13 also causes an increase in lysosomal volume in cancer but not in non-cancer cells, which may contribute at least in part to its preferential cancer cell-killing. The cancer cell-killing effect of compound 13 is highly potentiated when combined with either bortezomib or monastrol.

Effects of Hydroxychloroquine on Proteinuria in IgA Nephropathy: A Randomized Controlled Trial

RATIONALE & OBJECTIVE

Despite optimization of renin-angiotensin-aldosterone system (RAAS) inhibition, patients with immunoglobulin A nephropathy (IgAN) and persistent proteinuria remain at risk for kidney failure. We evaluated the efficacy and safety of hydroxychloroquine (HCQ), an immunomodulator, when added to the treatment regimen of patients with IgAN.

STUDY DESIGN

Double-blind, randomized, placebo-controlled, phase 2 clinical trial.

SETTING & PARTICIPANTS

Participants had IgAN (proteinuria with protein excretion of 0.75-3.5g/d and estimated glomerular filtration rate>30mL/min/1.73m²) and were receiving optimized RAAS inhibitor therapy.

INTERVENTIONS

Patients were randomly assigned 1:1 to receive daily oral HCQ or a placebo for 6 months.

OUTCOMES

The primary outcome was percentage change in proteinuria between baseline and 6 months.

RESULTS

60 participants (mean estimated glomerular filtration rate, 53.8mL/min/1.73m²; median urine protein excretion, 1.7g/d) were recruited and randomly assigned to receive HCQ (n=30) or placebo (n=30). Percentage change in proteinuria at 6 months was significantly different between the HCQ group and the placebo group (-48.4% [IQR, -64.2%, -30.5%] vs 10.0% [IQR, -38.7%, 30.6%]; P<0.001, respectively). At 6 months, median proteinuria level was significantly lower in the HCQ group than in the placebo group (0.9 [IQR, 0.6, 1.0] g/d vs 1.9 [IQR, 0.9, 2.6] g/d; P=0.002, respectively). No serious adverse events were recorded during the study in either study group.

LIMITATIONS

The short treatment period and lack of postwithdrawal observations limit conclusions about long-term renoprotective efficacy and safety.

CONCLUSIONS

HCQ in addition to optimized RAAS inhibition significantly reduced proteinuria in patients with IgAN over 6 months without evidence of adverse events. These findings require confirmation in larger treatment trials.

FUNDING

This study was supported by grants from a government entity, the Capital of Clinical Characteristics, and the Applied Research Fund.

TRIAL REGISTRATION

Registered at ClinicalTrials.gov with study number NCT02942381.

Systemic lupus erythematosus: Diagnosis and clinical management

Systemic lupus erythematosus (SLE) is a worldwide chronic autoimmune disease which may affect every organ and tissue. Genetic predisposition, environmental triggers, and the hormonal milieu, interplay in disease development and activity. Clinical manifestations and the pattern of organ involvement are widely heterogenous, reflecting the complex mosaic of disrupted molecular pathways converging into the SLE clinical phenotype. The SLE complex pathogenesis involves multiple cellular components of the innate and immune systems, presence of autoantibodies and immunocomplexes, engagement of the complement system, dysregulation of several cytokines including type I interferons, and disruption of the clearance of nucleic acids after cell death. Use of immunomodulators and immunosuppression has altered the natural course of SLE. In addition, morbidity and mortality in SLE not only derive from direct immune mediated tissue damage but also from SLE and treatment associated complications such as accelerated coronary artery disease and increased infection risk. Here, we review the diagnostic approach as well as the etiopathogenetic rationale and clinical evidence for the management of SLE. This includes 1) lifestyle changes such as avoidance of ultraviolet light; 2) prevention of comorbidities including coronary artery disease, osteoporosis, infections, and drug toxicities; 3) use of immunomodulators (i.e. hydroxychloroquine and vitamin D); and 4) immunosuppressants and targeted therapy. We also review new upcoming agents and regimens currently under study.

Inhibition of Cyclic GMP-AMP Synthase Using a Novel Antimalarial Drug Derivative in Trex1-Deficient Mice

OBJECTIVE

Type I interferon (IFN) is strongly implicated in the pathogenesis of systemic lupus erythematosus (SLE) as well as rare monogenic interferonopathies such as Aicardi-Goutières syndrome (AGS), a disease attributed to mutations in the DNA exonuclease TREX1. The DNA-activated type I IFN pathway cyclic GMP-AMP (cGAMP) synthase (cGAS) is linked to subsets of AGS and lupus. This study was undertaken to identify inhibitors of the DNA-cGAS interaction, and to test the lead candidate drug, X6, in a mouse model of AGS.

METHODS

Trex1^-/- mice were treated orally from birth with either X6 or hydroxychloroquine (HCQ) for 8 weeks. Expression of IFN-stimulated genes (ISGs) was quantified by quantitative polymerase chain reaction. Multiple reaction monitoring by ultra-performance liquid chromatography coupled with tandem mass spectrometry was used to quantify the production of cGAMP and X6 drug concentrations in the serum and heart tissue of Trex1^-/- mice.

RESULTS

On the basis of the efficacy-to-toxicity ratio established in vitro, drug X6 was selected as the lead candidate for treatment of Trex1^-/- mice. X6 was significantly more effective than HCQ in attenuating ISG expression in mouse spleens (P < 0.01 for Isg15 and Isg20) and hearts (P < 0.05 for Isg15, Mx1, and Ifnb, and P < 0.01 for Cxcl10), and in reducing the production of cGAMP in mouse heart tissue (P < 0.05), thus demonstrating target engagement by the X6 compound. Of note, X6 was also more effective than HCQ in reducing ISG expression in vitro (P < 0.05 for IFI27 and MX1, and P < 0.01 for IFI44L and PKR) in human peripheral blood mononuclear cells from patients with SLE.

CONCLUSION

This study demonstrates that X6 is superior to HCQ for the treatment of an experimental autoimmune myocarditis mediated in vivo by the cGAS/stimulator of IFN genes (cGAS/STING) pathway. The findings suggest that drug X6 could be developed as a novel treatment for AGS and/or lupus to inhibit activation of the cGAS/STING pathway.

Pharmacotherapy Pearls in Rheumatology for the Care of Older Adult Patients: Focus on Oral Disease-Modifying Antirheumatic Drugs and the Newest Small Molecule Inhibitors

Providing safe and effective pharmacotherapy to geriatric patients with rheumatologic disorders is challenging. Multidisciplinary care involving rheumatologists, primary care physicians, and other specialties can optimize benefit and reduce adverse outcomes. Oral disease-modifying antirheumatic drugs, including methotrexate, hydroxychloroquine, sulfasalazine, and leflunomide, and the small molecule inhibitors tofacitinib and apremilast have distinctive monitoring requirements and specific adverse reaction profiles. This article provides clinically relevant pearls for use of these interventions in older patients.

Chloroquine and amodiaquine enhance AMPK phosphorylation and improve mitochondrial fragmentation in diabetic tubulopathy

We investigated the effects of chloroquine (CQ) and amodiaquine (AQ) on AMPK phosphorylation in renal tubular cells in a diabetic environment in vivo and in vitro. We also examined whether CQ- or AQ-mediated AMPK activity restoration attenuated diabetic tubulopathy by normalizing mitochondrial fragmentation. Human renal proximal epithelial cells (HKC8) were incubated in high-glucose conditions. Diabetes was induced with streptozotocin in male C57/BL6J mice. Treatment with CQ or AQ abolished high-glucose-induced phospho-AMPK and phosph-PGC1α down-regulation in HKC8 cells. Improvements in functional mitochondrial mass and balanced fusion/fission protein expression were observed in HKC8 cells after treatment with CQ or AQ in high-glucose conditions. Moreover, decreased mitochondrial ROS production and reduced apoptotic and fibrotic protein expression were noted in HKC8 cells after treatment with CQ or AQ, even in high-glucose conditions. CQ and AQ treatment effectively mitigated albuminuria and renal histopathologic changes and increased AMPK activity in the kidneys of diabetic mice. Electron microscopy analysis showed that mitochondrial fragmentation was decreased, and 8-OHdG content was low in the renal tubular cells of the CQ and AQ treatment groups compared with those of the diabetic control group. Our results suggest that CQ and AQ may be useful treatments for patients with diabetic kidney disease.

Double-Edged Effect of Hydroxychloroquine on Human Umbilical Cord-Derived Mesenchymal Stem Cells Treating Lupus Nephritis in MRL/lpr Mice

Hydroxychloroquine (HCQ) and human umbilical cord-derived mesenchymal stem cells (UC-MSCs) were used to treat systemic lupus erythematosus (SLE), respectively. However, the effect of HCQ on UC-MSCs in lupus nephritis (LN) has not been investigated. In this study, HCQ and UC-MSCs were used in MRL/lpr mice. Surprisingly, although the treatment of both HCQ and UC-MSCs could ameliorate renal damage separately, the presence of HCQ decreased unexpectedly the therapeutic effects of UC-MSCs through interfering expression of IFN-γ. However, HCQ-pretreated UC-MSCs showed significant improvements of renal morphology and function more rapidly than that of UC-MSCs and HCQ alone. To test the role of HCQ in UC-MSCs, MRL/lpr mice and SLE patients' peripheral blood were used in vivo and in vitro. Results showed that after administration of UC-MSCs pretreated by HCQ, CXCR3 expression in renal tissues, serum IL-2, and IgM levels decreased significantly, and serum IL-10 level increased significantly. HCQ pretreatment caused a significant decrease of TNF-α and MCP-1 secretion and an increase of IL-1β and CXCL10 release from UC-MSCs. Our results indicate that HCQ plays a double-edged role in UC-MSCs. It is necessary for clinical treatment to pre-evaluated concomitant application of UC-MSCs with HCQ. More importantly, the alterative expression of IFN-γ, the improvement of migration ability of UC-MSCs, the regulation of Th1/Th2 balance, and the changes of antibodies secretion in B cell might be involved in its mechanisms.

A bibliometric review of drug repurposing

We have conducted a bibliometric review of drug repurposing by scanning >25 million papers in PubMed and using text-mining methods to gather, count and analyze chemical-disease therapeutic relationships. We find that >60% of the ∼35,000 drugs or drug candidates identified in our study have been tried in more than one disease, including 189 drugs that have been tried in >300 diseases each. Whereas in the majority of cases these drugs were applied in therapeutic areas close to their original use, there have been striking, and perhaps instructive, successful attempts of drug repurposing for unexpected, novel therapeutic areas.

Research and therapeutics-traditional and emerging therapies in systemic lupus erythematosus

This review summarizes traditional and emerging therapies for SLE. Evidence suggests that the heterogeneity of SLE is a crucial aspect contributing to the failure of large clinical trials for new targeted therapies. A clearer understanding of the mechanisms driving disease pathogenesis combined with recent advances in medical science are predicted to enable accelerated progress towards improved SLE diagnosis and personalized approaches to treatment.

Is hydroxychloroquine effective in treating primary Sjogren's syndrome: a systematic review and meta-analysis

BACKGROUND

To systematically review and assess the efficacy and safety of hydroxychloroquine (HCQ) for treating primary Sjogren's syndrome (pSS).

METHODS

Five electronic databases (Pubmed, EMBASE, Web of science, Ovid, Cochrane Library) were searched for randomized controlled trials and retrospective or prospective studies published in English that reported the effect of HCQ on pSS. The subjective symptoms (sicca symptoms, fatigue and pain) and the objective indexes (erythrocyte sedimentation rate and Schirmer test) were assessed as main outcome measures. A meta-analysis and descriptive study on the efficacy and safety of HCQ were conducted. The estimate of the effect of HCQ treatment was expressed as a proportion together with 95% confidence interval, and plotted on a forest plot.

RESULTS

Four trials with totals of 215 SS patients, including two randomized controlled trials, one double blind crossover trial and one retrospective open-label study, were analyzed in this review. For dry mouth and dry eyes, the effectiveness of HCQ treatment was essentially the same as placebo treatment. For fatigue, the effectiveness of HCQ was lower than placebo. The efficacy of HCQ in treating pain associated with pSS was superior to that of the placebo. There was no significant difference between HCQ-treated groups and controls in terms of Schirmer test results, but HCQ could reduce the erythrocyte sedimentation rate compare with placebo. A descriptive safety assessment showed that gastrointestinal adverse effects were the most common adverse effects associated with HCQ.

CONCLUSIONS

This systematic review showed that there is no significant difference between HCQ and placebo in the treatment of dry mouth and dry eye in pSS. Well-designed, randomized, controlled trials are needed to provide higher-quality evidence to confirm our findings, and future studies should focus on some other index or extraglandular measures, such as cutaneous manifestations, to further explore the therapeutic effect of HCQ in pSS.

Scavenging nucleic acid debris to combat autoimmunity and infectious disease

Nucleic acid-containing debris released from dead and dying cells can be recognized as damage-associated molecular patterns (DAMPs) or pattern-associated molecular patterns (PAMPs) by the innate immune system. Inappropriate activation of the innate immune response can engender pathological inflammation and autoimmune disease. To combat such diseases, major efforts have been made to therapeutically target the pattern recognition receptors (PRRs) such as the Toll-like receptors (TLRs) that recognize such DAMPs and PAMPs, or the downstream effector molecules they engender, to limit inflammation. Unfortunately, such strategies can limit the ability of the immune system to combat infection. Previously, we demonstrated that nucleic acid-binding polymers can act as molecular scavengers and limit the ability of artificial nucleic acid ligands to activate PRRs. Herein, we demonstrate that nucleic acid scavengers (NASs) can limit pathological inflammation and nucleic acid-associated autoimmunity in lupus-prone mice. Moreover, we observe that such NASs do not limit an animal's ability to combat viral infection, but rather their administration improves survival when animals are challenged with lethal doses of influenza. These results indicate that molecules that scavenge extracellular nucleic acid debris represent potentially safer agents to control pathological inflammation associated with a wide range of autoimmune and infectious diseases.

Impact of hydroxychloroquine on preterm delivery and intrauterine growth restriction in pregnant women with systemic lupus erythematosus: a descriptive cohort study

OBJECTIVE

The aim of this study was to evaluate the effect of hydroxychloroquine (HCQ) on fetal preterm delivery and intrauterine growth restriction (IUGR) in a cohort of pregnant women with systemic lupus erythematosus (SLE).

METHODS

Over an 11-year period (January 1, 2001 to December 31, 2011), all women with SLE and admitted to deliver after 22 weeks of gestation to Bordeaux University Hospital (France), were retrospectively enrolled in the present study. The population was then split into two groups based on the treatment they received: HCQ exposed (HCQ+) versus HCQ non-exposed (HCQ-) group.

RESULTS

118 pregnancies were included, 41 in the HCQ+ group and 77 in the HCQ- group. The rate of adverse fetal outcome was significantly lower in the HCQ+ group (p = 0.001), particularly in terms of preterm delivery, 15.8% versus 44.2% (p = 0.006), and IUGR, 10.5% versus 28.6% (p = 0.03). No adverse outcomes were reported in the HCQ+ group.

CONCLUSION

HCQ reduces neonatal morbidity in women with SLE by significantly decreasing the rate of prematurity and intrauterine growth restriction.

Hydroxychloroquine's Efficacy as an Antiplatelet Agent Study in Healthy Volunteers: A Proof of Concept Study

BACKGROUND

With the inflammatory model of atherosclerosis taking center stage, anti-inflammatory drugs hold a promising place in the therapy of cardiovascular disease (CVD). Recent studies showed that hydroxychloroquine (HCQ) was protective against thrombovascular events in lupus erythematosus and traditional cardiovascular risk factors in patients with rheumatoid arthritis. Some preliminary experimental data have shown that it may prevent platelet activation too.

OBJECTIVE

To evaluate the antiplatelet activity of HCQ when given alone and in combination with aspirin (ASA) and compare it with ASA alone and ASA plus clopidogrel (CLOP) in healthy human volunteers.

METHODS

In part 1 of the study, 8 volunteers were given HCQ for 7 days. In part 2, 12 volunteers were randomly assigned in a 1:1:1 ratio to the 3 groups in which 2 of the 3 treatments, ASA, ASA plus CLOP, and ASA plus HCQ, were given in the 2 treatment periods separated by a 14-day washout period using the incomplete block design. Inhibition of platelet aggregation (IPA) was measured by light transmission aggregometry.

RESULTS

When arachidonic acid (AA) was used as agonist, HCQ given alone showed a significant reduction in platelet aggregation (11.0% ± 4.2%, P = .03). The IPA was significantly increased when ASA plus HCQ was compared with ASA alone (31.2% ± 8.1%, P = .002). This synergistic effect was not seen with adenosine diphosphate and collagen as agonists. Levels of serum 11-dehydrothromboxane B2, a stable marker of thromboxane A2 production, were not significantly different between the groups. There was also a significant decrease in fibrinogen and erythrocyte sedimentation rate values when HCQ was used alone or in combination with ASA.

CONCLUSION

This study suggests that HCQ has antiplatelet properties possibly through the AA pathway (downstream to thromboxane A2 production). With possible additional beneficial effects over the traditional CVD risk factors, larger studies in the future might explore HCQ's potential as an antiplatelet agent.

Chloroquine targets pancreatic cancer stem cells via inhibition of CXCR4 and hedgehog signaling

Pancreatic ductal adenocarcinoma is one of the deadliest carcinomas and is characterized by highly tumorigenic and metastatic cancer stem cells (CSC). CSCs evade available therapies, which preferentially target highly proliferative and more differentiated progenies, leaving behind CSCs as a putative source for disease relapse. Thus, to identify potentially more effective treatment regimens, we screened established and new compounds for their ability to eliminate CSCs in primary pancreatic cancer (stem) cells in vitro and corresponding patient-derived pancreatic cancer tissue xenografts in vivo. Intriguingly, we found that in vitro treatment with the antimalarial agent chloroquine significantly decreased CSCs, translating into diminished in vivo tumorigenicity and invasiveness in a large panel of pancreatic cancers. In vivo treatment in combination with gemcitabine was capable of more effectively eliminating established tumors and improved overall survival. The inhibitory effect of chloroquine was not related to inhibition of autophagy, but was due to inhibition of CXCL12/CXCR4 signaling, resulting in reduced phosphorylation of ERK and STAT3. Furthermore, chloroquine showed potent inhibition of hedgehog signaling by decreasing the production of Smoothened, translating into a significant reduction in sonic hedgehog-induced chemotaxis and downregulation of downstream targets in CSCs and the surrounding stroma. Our study demonstrates that via to date unreported effects, chloroquine is an effective adjuvant therapy to chemotherapy, offering more efficient tumor elimination and improved cure rates. Chloroquine should be further explored in the clinical setting as its success may help to more rapidly improve the poor prognosis of patients with pancreatic cancer.

Pharmacology of Chloroquine and Hydroxychloroquine

The 4-aminoquinolines are weak bases that are completely absorbed from the gastrointestinal tract, sequestered in peripheral tissues, metabolized in the liver to pharmacologically active by-products, and excreted via the kidneys and the feces. The parent drugs and metabolites are excreted with a half-life of elimination of approximately 40 days. However, slow release from sequestered stores of the drugs means that after discontinuation, they continue to be released into the plasma for years. Correct dosing is based on the ideal body weight of the patient, which depends on height. The 4AQs diminish autoimmunity without compromising immunity to infections.

Antimalarials in dermatology: mechanism of action, indications, and side effects

Antimalarial drugs have been in common use in dermatology since the 1950s. Their mechanism of action is complex, and it is now known that they act through various pathways. We review the indications for antimalarials in dermatology, their adverse effects, and some less well-known effects, such as their antithrombotic and hypolipidemic action. The most recent recommendations concerning ophthalmological screening in patients on antimalarials are also reviewed.

The role of antimalarial agents in the treatment of SLE and lupus nephritis

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease that affects various organs. Lupus nephritis is one of the most common, and most important, serious manifestations of SLE. Antimalarial agents are part of the immunomodulatory regimen used to treat patients with SLE; however, their role in the treatment of patients with lupus nephritis in particular is less well recognized, especially by nephrologists. Not all antimalarial agents have been used in the treatment of lupus; this Review will focus on studies using chloroquine and hydroxychloroquine. In addition, this Review will briefly describe the history of antimalarial drug use in patients with SLE, the theorized mechanisms of action of the agents chloroquine and hydroxychloroquine, their efficacy in patients with SLE and those with lupus nephritis, their use in pregnancy, and potential adverse effects. The Review will also cover the latest recommendations regarding monitoring for hydroxychloroquine-associated or chloroquine-associated retinopathy. Overall, antimalarial drugs have numerous beneficial effects in patients with SLE and lupus nephritis, and have a good safety profile.

Hydroxychloroquine for subglottic stenosis: a novel therapy in the battle for air

Upper airway obstruction due to subglottic edema and granulation tissue proliferation may cause severe morbidity and may be life threatening. Hydroxychloroquine interferes with antigen processing by means of raising lysosomal pH and immune response modulation. Herein, we present the outcome of a steroid-sparing treatment using hydroxychloroquine in an 80-year-old man with acquired subglottic stenosis and steroid dependency. Twice daily oral hydroxychloroquine at 2 mg/kg/day allowed cessation of systemic steroids without recurrence of the stenosis. Successful weaning of the hydroxychloroquine took place over a 5-month period.

Increased plasma myeloperoxidase levels in systemic lupus erythematosus

The objective of the study was to quantify plasma myeloperoxidase (MPO) levels in systemic lupus erythematosus (SLE) patients and to evaluate a correlation between MPO levels and disease activity. 71 female SLE patients and 70 controls were studied. Patients were divided into two groups: Group I (n = 48) with SLEDAI-2K score 0-5 and Group II (n = 23) with SLEDAI-2K score > or = 6. Mann-Whitney test and Spearman rank correlation were used. Two-sided P values < 0.05 were considered significant and P values > or = 0.05 and < 0.08 were considered as a tendency. The median age of patients and controls were comparable and the mean disease duration was 99.2 +/- 61.7 months. MPO levels were higher in patients than controls [5.99 (4.38-8.64) vs. 5.00 (3.33-7.08) ng/ml, P = 0.02]. We did not find correlation between MPO levels and SLEDAI-2k (r = 0.07, P = 0.58). MPO levels were not affected by treatment with prednisone, cyclophosphamide or azathioprine, however, a tendency of lower levels was observed among patients under antimalarial drugs. There was no significant difference in MPO plasma levels between Group I and Group II (5.83 vs. 6.02 ng/ml, P = 0.99). MPO levels were higher in patients with arthritis than in those without arthritis (8.15 vs. 5.56 ng/ml, P = 0.010). No difference was observed among patients with and without other organs/systems involvement. SLE patients presented increased MPO plasma levels than healthy controls. Despite the lack of correlation between MPO plasma levels and disease activity, the higher MPO levels in patients with articular involvement suggests MPO may play a different role in the inflammatory process of some SLE manifestations.