The influence of antimalarial treatment on IL-1beta, IL-6 and TNF-alpha mRNA expression on UVB-irradiated skin in systemic lupus erythematosus

Hydroxychloroquine improves pregnancy outcomes in patients undergoing frozen embryo transfer with positive serum autoantibodies

PROBLEM

Does hydroxychloroquine (HCQ) improve pregnancy outcomes after frozen embryo transfer (FET) cycles in patients who are positive for autoantibodies？ METHOD OF STUDY: This was a retrospective clinical study involving 128 patients who were positive for autoantibodies undergoing FET cycles between October 2017 and December 2022. Subjects were divided into two groups: a study group of 65 cycles with HCQ (HCQ was administered orally over 2 months before transplantation and continued during the first trimester) and a control group consisting of 63 cycles without HCQ (no HCQ was used throughout the FET cycle). Each patient was enrolled in the cohort only once. Then, we analyzed the clinical pregnancy outcomes between the two groups.

RESULTS

Analysis showed that HCQ was a factor that independently associated with clinical pregnancy rate (CPR) OR (Odds Ratio): 3.106; 95% confidence interval (CI): 1.458-6.616; p = .003. Furthermore, the implantation rate (IR), CPR and ongoing pregnancy rate (OPR) of the treatment group were significantly higher than those in the control group. The biochemical pregnancy rate (BPR) and early miscarriage rate (EMR) were significantly lower than that in the control group (p = .029, p < .001).

CONCLUSION

We found that HCQ improved clinical pregnancy outcomes and reduced the rate of first-trimester abortion in patients who were positive for autoantibodies during FET cycles.

Thrombosis and Anticoagulation Therapy in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune inflammatory disease in which pathogenic autoantibodies and immune complexes are formed and mediate multiple organ and tissue damage. Thrombosis is one of the most common causes of death in patients with SLE. Anticoagulant therapy blocks the vicious cycle between inflammation and thrombosis, which may greatly improve the long-term prognosis of patients with SLE. However, the etiology and pathogenesis of this disease are very complicated and have not yet been fully clarified. Therefore, in the present review, we will highlight the characteristics and mechanisms of thrombosis and focus on the anticoagulant drugs commonly used in clinical practice, thus, providing a theoretical basis for scientific and reasonable anticoagulant therapy in clinical practice.

Myocardial infarctions, subtypes and coronary atherosclerosis in SLE: a case-control study

Objective

Patients with SLE have increased risk of myocardial infarction (MI). Few studies have investigated the characteristics of SLE-related MIs. We compared characteristics of and risk factors for MI between SLE patients with MI (MI-SLE), MI patients without SLE (MI-non-SLE) and SLE patients without MI (non-MI-SLE) to understand underlying mechanisms.

Methods

We identified patients with a first-time MI in the Karolinska SLE cohort. These patients were individually matched for age and gender with MI-non-SLE and non-MI-SLE controls in a ratio of 1:1:1. Retrospective medical file review was performed. Paired statistics were used as appropriate.

Results

Thirty-four MI-SLE patients (88% females) with a median age of 61 years were included. These patients had increased number of coronary arteries involved (p=0.04), and ≥50% coronary atherosclerosis/occlusion was numerically more common compared with MI-non-SLE controls (88% vs 66%; p=0.07). The left anterior descending artery was most commonly involved (73% vs 59%; p=0.11) and decreased (<50%) left ventricular ejection fraction occurred with similar frequency in MI-SLE and MI-non-SLE patients (45% vs 36%; p=0.79). Cardiovascular disease (44%, 5.9%, 12%; p<0.001) and coronary artery disease (32%, 2.9%, 0%; p<0.001), excluding MI, preceded MI/inclusion more commonly in MI-SLE than in MI-non-SLE and non-MI-SLE patients, respectively. MI-SLE patients had lower plasma albumin levels than non-MI-SLE patients (35 (29–37) vs 40 (37–42) g/L; p=0.002).

Conclusion

In the great majority of cases, MIs in SLE are associated with coronary atherosclerosis. Furthermore, MIs in SLE are commonly preceded by symptomatic vascular disease, calling for attentive surveillance of cardiovascular disease and its risk factors and early atheroprotective treatment.

Antimalarial drugs-are they beneficial in rheumatic and viral diseases?-considerations in COVID-19 pandemic

The majority of the medical fraternity is continuously involved in finding new therapeutic schemes, including antimalarial medications (AMDs), which can be useful in combating the 2019-nCoV: coronavirus disease (COVID-19). For many decades, AMDs have been widely used in the treatment of malaria and various other anti-inflammatory diseases, particularly to treat autoimmune disorders of the connective tissue. The review comprises in vitro and in vivo studies, original studies, clinical trials, and consensus reports for the analysis, which were available in medical databases (e.g., PubMed). This manuscript summarizes the current knowledge about chloroquine (CQ)/hydroxychloroquine (HCQ) and shows the difference between their use, activity, recommendation, doses, and adverse effects on two groups of patients: those with rheumatic and viral diseases (including COVID-19). In the case of connective tissue disorders, AMDs are prescribed for a prolonged duration in small doses, and their effect is observed after few weeks, whereas in the case of viral infections, they are prescribed in larger doses for a short duration to achieve a quick saturation effect. In rheumatic diseases, AMDs are well tolerated, and their side effects are rare. However, in some viral diseases, the effect of AMDs is questionable or not so noticeable as suggested during the initial prognosis. They are mainly used as an additive therapy to antiviral drugs, but recent studies have shown that AMDs can diminish the efficacy of some antiviral drugs and may cause respiratory, kidney, liver, and cardiac complications.

Hydroxychloroquine (HCQ) decreases the benefit of anti-PD-1 immune checkpoint blockade in tumor immunotherapy

Immunotherapy using checkpoint blockade (ICB) with antibodies such as anti-PD-1 has revolutionised the treatment of many cancers. Despite its use to treat COVID-19 patients and autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis, the effect of hydroxychloroquine (HCQ) on cancer immunotherapy has not been examined. In this study, remarkably, we find that HCQ alone, or in combination with azithromycin (AZ), at doses used to treat patients, decreased the therapeutic benefit of anti-PD-1 in cancer immunotherapy. No deleterious effect was seen on untreated tumors. Mechanistically, HCQ and HCQ/AZ inhibited PD-L1 expression on tumor cells, while specifically targeting the anti-PD-1 induced increase in progenitor CD8+CD44+PD-1+TCF1+ tumor infiltrating T cells (TILs) and the generation of CD8+CD44+PD-1+ effectors. Surprisingly, it also impaired the appearance of a subset of terminally exhausted CD8+ TILs. No effect was seen on the presence of CD4+ T cells, FoxP3+ regulatory T cells (Tregs), thymic subsets, B cells, antibody production, myeloid cells, or the vasculature of mice. This study indicates for the first time that HCQ and HCQ/AZ negatively impact the ability of anti-PD-1 checkpoint blockade to promote tumor rejection.

Advances in Drug Therapy for Systemic Lupus Erythematosus

BACKGROUND

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by a local or systemic inflammatory response. At present, the increasing research results show that the pathogenesis of the disease is complex, and the methods of clinical treatment also show diversity. This review analyzes and summarizes the existing mechanism research and drug treatment methods in order to provide a reference value for further drug research and development.

METHOD

We carried out a thorough literature search using databases. According to the main purpose of the article, irrelevant articles were excluded after further examination and directly relevant articles were included. Finally, the information related to the article was summarized.

RESULT

In this article, seventy-four articles are included. According to related articles, there are mainly four kinds of drugs, namely antimalarial drugs, glucocorticoids, immunosuppressive agents and biological agents. About fifty-five articles summarized the drugs for the treatment of systemic lupus erythematosus. The rest of the articles were related to the research progress of the mechanism of systemic lupus erythematosus.

CONCLUSION

This article describes the pathogenesis of systemic lupus erythematosus, and summarizes the traditional and new therapeutic drugs, which is not only beneficial to the treatment of lupus erythematosus patients, but also plays a vital reference significance for the future development of new systemic lupus erythematosus drugs.

Short-term high-dose gavage of hydroxychloroquine changes gut microbiota but not the intestinal integrity and immunological responses in mice

Aims

Hydroxychloroquine (HCQ), a widely used antimalarial drug, is proposed to treat coronavirus disease 2019 (COVID-19). However, no report is currently available regarding the direct effects of HCQ on gut microbiota, which is associated with the outcomes of elderly patients with COVID-19. Here, we first investigated the effects of HCQ on intestinal microecology in mice.

Main methods

Fifteen female C57BL/6J mice were randomly divided into two groups: HCQ group (n = 10) and control group (n = 5). Mice in the HCQ group were administered with HCQ at dose of 100 mg/kg by gavage daily for 14 days. The feces of mice were collected before and on the 7th and 14th days after HCQ challenge, and then analyzed by 16S rRNA amplicon sequencing. At the end of the experiment, the hematology, serum biochemistry and cytokines were determined, respectively. The mRNA expression of tight junction proteins in colonic tissues were also studied by RT-PCR.

Key findings

HCQ challenge had no effects on the counts of white blood cells, the levels of serum cytokines, and the gene expression of tight junction proteins in colon. HCQ also did not increase the content of serum d-lactate in mice. Notably, HCQ significantly decreased the diversity of gut microbiota, increased the relative abundance of phylum Bacteroidetes whereas decreased that of Firmicutes.

Significance

Short-term high dose HCQ challenge changes gut microbiota but not the intestinal integrity and immunological responses in mice. Special attention should be paid to the effects of HCQ on intestinal microecology in future clinical use.

The pathogenesis of cutaneous lupus erythematosus: The aberrant distribution and function of different cell types in skin lesions

Cutaneous lupus erythematosus (CLE) is an autoimmune disease with a broad range of cutaneous manifestations. In skin lesions of CLE, keratinocytes primarily undergo apoptosis. Interferon-κ(IFN-κ) is belonged to type I interferons (type I IFNs) and is selectively produced by keratinocytes. Recently, keratinocytes selectively produced IFN-κ is identified to be a key to trigger type I interferon responses in CLE. Other immune cells such as plasmacytoid dendritic cells (pDCs) are identified to be relevant origin of type I interferons (type I IFNs) which are central to the development of CLE lesions and responsible for mediating Th1 cell activity. Other types of cells such as neutrophils, B cells and Th17 cells also are involved in the development of this disease. The close interaction of those cells composes a comprehensive and complicated network in CLE. In this review, we discussed the aberrant distribution and function of different cells types involved in this disease and will offer a new direction for research and therapy in the near future.

Hydroxychloroquine in Dermatology and Beyond: Recent Update

Hydroxychloroquine is one of the most frequently used drugs in dermatology with a wide variety of uses due to its immunomodulatory, anti-inflammatory, photoprotective, and metabolic actions and low side effect profile. Demonstration of its antiviral action in vitro has led to renewed interest by physicians worldwide during the ongoing coronavirus disease of 2019 (COVID-19) pandemic. Like its immunomodulatory action, its antiviral activity is also due to its ability to alkalinize the intracytoplasmic milieu, leading to disordered viral entry/fusion and deranged viral protein synthesis. However, randomized controlled trials are the need of the hour to conclusively determine its clinical efficacy in such infections. A review of the multitude of mechanisms of action, updated screening and monitoring guidelines, drug interactions, side effects, and its use in special populations is described.

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.

Dissecting pharmacological effects of chloroquine in cancer treatment: interference with inflammatory signaling pathways

Chloroquines are 4-aminoquinoline-based drugs mainly used to treat malaria. At pharmacological concentrations, they have significant effects on tissue homeostasis, targeting diverse signaling pathways in mammalian cells. A key target pathway is autophagy, which regulates macromolecule turnover in the cell. In addition to affecting cellular metabolism and bioenergetic flow equilibrium, autophagy plays a pivotal role at the interface between inflammation and cancer progression. Chloroquines consequently have critical effects in tissue metabolic activity and importantly, in key functions of the immune system. In this article, we will review the work addressing the role of chloroquines in the homeostasis of mammalian tissue, and the potential strengths and weaknesses concerning their use in cancer therapy.

MicroRNA-145 attenuates IL-6-induced enhancements of sensitivity to UVB irradiation by suppressing MyD88 in HaCaT cells

MicroRNAs (miRNAs/miRs) play vital roles in various immune diseases including systemic lupus erythematosus (SLE). The current study aimed to assess the role of miR-145 in interleukin-6 (IL-6)-treated HaCaT cells under ultraviolet B (UVB) irradiation and further explore the potential regulatory mechanism. HaCaT cells were pretreated with IL-6 and then exposed to UVB to assess the effect of IL-6 on sensitivity of HaCaT cells to UVB irradiation. The levels of miR-145 and MyD88 were altered by transfection and the transfected efficiency was verified by quantitative reverse transcription polymerase chain reaction (qRT-PCR)/western blot analysis. Cell viability, percentage of apoptotic cells and expression levels of apoptosis-related factors were measured by trypan blue assay, flow cytometry assay, and western blot analysis, respectively. In addition, the levels of c-Jun N-terminal kinases (JNK) and nuclear factor-κB (NF-κB) signaling pathway-related factors were assessed by western blot analysis. IL-6 treatments significantly aggravated the reduction of cell viability and promotion of cell apoptosis caused by UVB irradiation in HaCaT cells. Interestingly, miR-145 level was augmented by UVB exposure and miR-145 mimic alleviated IL-6-induced increase of sensitivity to UVB irradiation in HaCaT cells, as dramatically increased cell viability and reduced cell apoptosis. Opposite effects were observed in miR-145 inhibitor-transfected cells. Meanwhile, MyD88 was negatively regulated by miR-145 and MyD88 mediated the regulatory effect of miR-145 on IL-6- and UVB-treated cells. In addition, miR-145 mimic inhibited the JNK and NF-κB pathways by down-regulating MyD88. In conclusion, the present study demonstrated that miR-145 alleviated IL-6-induced increase of sensitivity to UVB irradiation by down-regulating MyD88 in HaCaT cells.

Neuropsychiatric clinical manifestations in elderly patients treated with hydroxychloroquine: a review article

Little is known about the development of psychosis during hydroxychloroquine (HCQ) treatment, especially in elderly patients affected by rheumatic diseases, with multiple comorbidities and treatments. To summarize the available evidence on HCQ-induced psychosis in elders, we performed a literature review. Additionally, individual case safety reports sent to the European Pharmacovigilance database (EudraVigilance) with HCQ as suspected drug and related to adverse events belonging to the System Organ Class 'Psychiatric disorders' were shown. Over the years, evidence was published about the risk of neuropsychiatric clinical manifestations during HCQ treatment for rheumatic diseases, but few of them were related to elderly patients. These adverse events can include less severe clinical manifestations such as affect lability and nervousness or more severe conditions such as actual psychosis and suicidal tendencies, which frequency are actually unknown. The presence of risk factors in these patients may precipitate HCQ-induced psychosis and their precocious detection could be associated with a risk minimization. Among predisposing risk factors, there are the co-exposure to interacting drugs, alcohol intake, familial history of psychiatric diseases, female gender, and the concomitant use of low-dose glucocorticoids. In some cases it was possible to reverse psychotic behaviour with the antipsychotic treatment or with HCQ suspension.

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.

Inhibition of Toll-Like Receptor Signaling as a Promising Therapy for Inflammatory Diseases: A Journey from Molecular to Nano Therapeutics

The recognition of invading pathogens and endogenous molecules from damaged tissues by toll-like receptors (TLRs) triggers protective self-defense mechanisms. However, excessive TLR activation disrupts the immune homeostasis by sustained pro-inflammatory cytokines and chemokines production and consequently contributes to the development of many inflammatory and autoimmune diseases, such as systemic lupus erythematosus (SLE), infection-associated sepsis, atherosclerosis, and asthma. Therefore, inhibitors/antagonists targeting TLR signals may be beneficial to treat these disorders. In this article, we first briefly summarize the pathophysiological role of TLRs in the inflammatory diseases. We then focus on reviewing the current knowledge in both preclinical and clinical studies of various TLR antagonists/inhibitors for the prevention and treatment of inflammatory diseases. These compounds range from conventional small molecules to therapeutic biologics and nanodevices. In particular, nanodevices are emerging as a new class of potent TLR inhibitors for their unique properties in desired bio-distribution, sustained circulation, and preferred pharmacodynamic and pharmacokinetic profiles. More interestingly, the inhibitory activity of these nanodevices can be regulated through precise nano-functionalization, making them the next generation therapeutics or “nano-drugs.” Although, significant efforts have been made in developing different kinds of new TLR inhibitors/antagonists, only limited numbers of them have undergone clinical trials, and none have been approved for clinical uses to date. Nevertheless, these findings and continuous studies of TLR inhibition highlight the pharmacological regulation of TLR signaling, especially on multiple TLR pathways, as future promising therapeutic strategy for various inflammatory and autoimmune diseases.

Lupus Skin Is Primed for IL-6 Inflammatory Responses through a Keratinocyte-Mediated Autocrine Type I Interferon Loop

Cutaneous lupus erythematosus is a disfiguring and common manifestation in systemic lupus erythematosus, and the etiology of this predisposition for cutaneous inflammation is unknown. Here, we sought to examine the keratinocyte as an important source of IL-6 and define the mechanism for its increased production in cutaneous lupus erythematosus. Evaluation of discoid and subacute cutaneous lupus erythematosus lesions showed significant epidermal up-regulation of IL-6 compared with control via real-time PCR and immunohistochemistry. Keratinocytes from unaffected skin of lupus patients produced significantly more IL-6 compared with healthy control subjects after exposure to toll-like receptor 2, 3, or 4 agonists or exposure to UVB radiation. Pretreatment with type I interferons (IFN-α and IFN-κ) increased IL-6 production by control keratinocytes, and type I IFN blockade decreased IL-6 secretion by lupus keratinocytes. Secretion of keratinocyte-specific IFN-κ was significantly increased after toll-like receptor 2 and UVB treatment in lupus keratinocytes, and neutralization of IFN-κ decreased IL-6 production by lupus keratinocytes. Thus, lupus keratinocytes are primed for IL-6 hyperproduction in a type I IFN-dependent manner. Increased production of IFN-κ by lupus keratinocytes drives this response, indicating that IFN-κ may play a pathogenic role in cutaneous lupus erythematosus and serve as a target for treatment.

Therapy and pharmacological properties of hydroxychloroquine and chloroquine in treatment of systemic lupus erythematosus, rheumatoid arthritis and related diseases

OBJECTIVES

This review examines the pharmacokinetics, modes of action and therapeutic properties of the anti-malarial drugs, hydroxychloroquine (HCQ) and chloroquine (CQ), in the treatment of systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and related conditions, as well as osteoarthritis (OA).

KEY FINDINGS

Both HCQ and CQ have historically been employed successfully for the treatment of SLE and RA for over 70 years. HCQ has been used extensively for SLE where it has a good reputation for controlling the dermatological complications in SLE. It has also been reported to effectively control the symptoms of Sjøgren's syndrome, as well as preventing thrombosis in phospholipid antibody (aPL) syndrome. In RA and SLE, HCQ is preferred because of the lower incidence of gastrointestinal adverse reactions compared with CQ and it might have a lower risk of ocular adverse reactions. There is increasing evidence that HCQ may reduce atherosclerosis and risks of cardiovascular disease in rheumatic patients. Both HCQ and CQ have been shown to improve glycaemia and reduce the risks of type II diabetes mellitus. Although both HCQ and CQ are effective in low-moderate RA, HCQ is now preferred as part of combination therapy for more severe disease. The advantages of combination therapy are that the doses of the individual drugs may be lowered so reducing adverse reactions. Both HCQ and CQ are diastereoisomers, have basic properties and are given as the sulphate and phosphate salts. While being relatively well absorbed orally and with good bioavailability, they have long and variable plasma terminal elimination half-lives (approximately 40-60 days). This reflects their high volume of distribution, V D (HCQ 44,000L; CQ 65,000L) which extends into aqueous compartments, long mean residence time (HCQ 1300 h; CQ 900 h) and with about half the drugs (metabolites) undergoing renal clearance. The strong binding to melanin reflects the ocular injury and dermatological properties of these drugs. The consensus is that the occurrence of ocular adverse reactions can be minimised by close attention to the dose (which should be set on a body weight basis) with regular (e.g. quarterly) retinal examination. Although HCQ and CQ can pass through the placenta, the use of these drugs during pregnancy does not appear to risk harm to the baby and might be beneficial to the mother with SLE and her child by controlling the SLE disease activity, which is known to be an important factor affecting pregnancy outcome. The modes of action of HCQ and CQ in these arthritides represent somewhat of an enigma. Undoubtedly, these drugs have multiple actions related, in part, their ability to accumulate in lysosomes and autophagosomes of phagocytic cells as well as affecting MHC Class II expression and antigen presentation; actions of the production of pro-inflammatory cytokines [e.g. interleukin-1 (IL-1) tumour necrosis factor-α (TNFα)]; control of toll-like receptor-9 activation; and leucocyte generation of reactive oxygen species (ROS); i.e. antioxidant activity. The actions of these drugs on T and B cells are less clear but may depend on these leucocyte-mediated actions. Anti-malarials also protect against cytokine-mediated cartilage resorption. This and other actions may underlie the potential benefits in treating OA. The exact relationships of these various actions, mostly determined in vitro, have not been specifically defined in vivo or ex vivo in relation to clinical efficacy.

OUTCOMES

HCQ and CQ have a good reputation for being effective and relatively safe treatments in SLE, mild-moderate RA and Sjøgren's syndrome. There is need for (a) more information on their mode of action in relation to the control of these diseases, (b) scope for developing formulations that have improved pharmacokinetic and therapeutic properties and safety, and (c) further exploring their use in drug combinations not only with other disease modifying agents but also with biologics.

Staphlyococcus aureus phenol-soluble modulins stimulate the release of proinflammatory cytokines from keratinocytes and are required for induction of skin inflammation

Staphylococcus aureus is a human commensal that colonizes the skin. While it is normally innocuous, it has strong associations with atopic dermatitis pathogenesis and has become the leading cause of skin and soft tissue infections in the United States. The factors that dictate the role of S. aureus in disease are still being determined. In this work, we utilized primary keratinocyte culture and an epidermal murine colonization model to investigate the role of S. aureus phenol-soluble modulins (PSMs) in proinflammatory cytokine release and inflammation induction. We demonstrated that many species of Staphylococcus are capable of causing release of interleukin 18 (IL-18) from keratinocytes and that S. aureus PSMs are necessary and sufficient to stimulate IL-18 release from keratinocytes independently of caspase 1. Further, after 7 days of epicutaneous exposure to wild-type S. aureus, but not S. aureus Δpsm, we saw dramatic changes in gross pathology, as well as systemic release of proinflammatory cytokines. This work demonstrates the importance of PSM peptides in S. aureus-mediated inflammatory cytokine release from keratinocytes in vitro and in vivo and further implicates PSMs as important contributors to pathogenesis.

Kaposi's sarcoma: etiology and pathogenesis, inducing factors, causal associations, and treatments: facts and controversies

Kaposi's sarcoma (KS), an angioproliferative disorder, has a viral etiology and a multifactorial pathogenesis hinged on an immune dysfunction. The disease is multifocal, with a course ranging from indolent, with only skin manifestations to fulminant, with extensive visceral involvement. In the current view, all forms of KS have a common etiology in human herpesvirus (HHV)-8 infection, and the differences among them are due to the involvement of various cofactors. In fact, HHV-8 infection can be considered a necessary but not sufficient condition for the development of KS, because further factors (genetic, immunologic, and environmental) are required. The role of cofactors can be attributed to their ability to interact with HHV-8, to affect the immune system, or to act as vasoactive agents. In this contribution, a survey of the current state of knowledge on many and various factors involved in KS pathogenesis is carried out, in particular by highlighting the facts and controversies about the role of some drugs (quinine analogues and angiotensin-converting enzyme inhibitors) in the onset of the disease. Based on these assessments, it is possible to hypothesize that the role of cofactors in KS pathogenesis can move toward an effect either favoring or inhibiting the onset of the disease, depending on the presence of other agents modulating the pathogenesis itself, such as genetic predisposition, environmental factors, drug intake, or lymph flow disorders. It is possible that the same agents may act as either stimulating or inhibiting cofactors according to the patient's genetic background and variable interactions. Treatment guidelines for each form of KS are outlined, because a unique standard therapy for all of them cannot be considered due to KS heterogeneity. In most cases, therapeutic options, both local and systemic, should be tailored to the patient's peculiar clinical conditions.

Hydroxychloroquine decreases Th17-related cytokines in systemic lupus erythematosus and rheumatoid arthritis patients

OBJECTIVES

Hydroxychloroquine is an antimalarial agent that has been used in systemic lupus erythematosus and rheumatoid arthritis treatment for many years. Recently, novel mechanisms of action have been proposed, thereby broadening the therapeutic perspective of this medication. The purpose of this study was to evaluate the immunomodulatory activity of hydroxychloroquine in T helper 17 (Th17) cytokines in healthy individuals and patients.

METHODS

Eighteen female patients with systemic lupus erythematosus (mean age 39.0±12.9 years) and 13 female patients with rheumatoid arthritis (mean age 51.5±7.7 years) were recruited from Universidade Federal de Pernambuco-Brazil. The patients were included after fulfilling four classification criteria for systemic lupus erythematosus or rheumatoid arthritis from the American College of Rheumatology. After being stimulated with phorbol 12-myristate 13-acetate and ionomycin in the absence or presence of different concentrations of hydroxychloroquine, the interleukin 6, 17 and 22 levels were quantified with an enzyme-linked immunosorbent assay in culture supernatants of peripheral blood mononuclear cells from healthy individuals and patients.

RESULTS

We demonstrated that in peripheral blood mononuclear cells from healthy volunteers and in systemic lupus erythematosus and rheumatoid arthritis patients, there was a significant reduction in the IL-6, IL-17 and IL-22 supernatant levels after adding hydroxychloroquine. CONCLUSIONS Our in vitro results demonstrated that hydroxychloroquine inhibits IL-6, IL-17 and IL-22 production and contributes to a better understanding of the mechanism of action of this medication.

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.