Hydroxychloroquine inhibits calcium signals in T cells: a new mechanism to explain its immunomodulatory properties

Implant delivering hydroxychloroquine attenuates vaginal T lymphocyte activation and inflammation

Evidence suggests that women who are naturally resistant to HIV infection exhibit low baseline immune activation at the female genital tract (FGT). This "immune quiescent" state is associated with lower expression of T-cell activation markers, reduced levels of gene transcription and pro-inflammatory cytokine or chemokine production involved in HIV infection while maintaining an intact immune response against pathogens. Therefore, if this unique immune quiescent state can be pharmacologically induced locally, it will provide an excellent women-oriented strategy against HIV infection To our knowledge, this is the first research article evaluating in vivo, an innovative trackable implant that can provide controlled delivery of hydroxychloroquine (HCQ) to successfully attenuate vaginal T lymphocyte activation and inflammation in a rabbit model as a potential strategy to induce an "immune quiescent" state within the FGT for the prevention of HIV infection. This biocompatible implant can deliver HCQ above therapeutic concentrations in a controlled manner, reduce submucosal immune cell recruitment, improve mucosal epithelium integrity, decrease protein and gene expression of T-cell activation markers, and attenuate the induction of key pro-inflammatory mediators. Our results suggest that microbicides designed to maintain a low level of immune activation at the FGT may offer a promising new strategy for reducing HIV infection.

Long-term use of hydroxychloroquine reduces antiphospholipid antibodies levels in patients with primary antiphospholipid syndrome

Hydroxychloroquine (HCQ) was suggested to play a role in lowering antiphospholipid antibody titers and preventing thrombotic recurrences in patients with systemic lupus erythematosus, but few data are available in patients with primary antiphospholipid syndrome (PAPS). In this retrospective, propensity score-matched cohort study, we evaluated the impact of HCQ on aPL titers and the incidence of thrombotic events in 57 exposed patients compared to 57 not exposed patients. These were matched for sex/type of disease onset/follow-up duration, age at the beginning of the follow-up ±10 years and initial date of the follow-up ±5 years. At baseline, no significant differences in demographical, clinical and serological features were observed between the two groups except for positive anti-extractable nuclear antigen antibodies (21 % in HCQ exposed vs 0 % in HCQ not exposed, P = 0.001). Both the levels of IgG anti-cardiolipin and IgG/IgM anti-β2-glycoprotein I (anti-β2GPI) were significantly reduced at end of follow-up compared to the baseline in HCQ-exposed patients, while there were no differences in the other group. Moreover, anti-β2GPI IgG titers were significantly decreased when the end of follow-up was compared between the two groups (P < 0.002). Among patients with a history of thrombosis, the annual incidence of recurrence was 1.16 % in HCQ exposed and 1.71 % in not exposed patients, with a significant reduction in the incidence of arterial events (0 vs 1.14 %). This study shows a strong reduction in aPL titers together with an apparent decrease in the incidence of arterial thrombosis recurrence in PAPS patients treated with HCQ.

Protective Effects of Hydroxychloroquine against Accelerated Atherosclerosis in Systemic Lupus Erythematosus

Cardiovascular (CV) morbidity and mortality are a challenge in management of patients with systemic lupus erythematosus (SLE). Higher risk of CV disease in SLE patients is mostly related to accelerated atherosclerosis. Nevertheless, high prevalence of traditional cardiovascular risk factors in SLE patients does not fully explain the increased CV risk. Despite the pathological bases of accelerated atherosclerosis are not fully understood, it is thought that this process is driven by the complex interplay between SLE and atherosclerosis pathogenesis. Hydroxychloroquine (HCQ) is a cornerstone in treatment of SLE patients and has been thought to exert a broad spectrum of beneficial effects on disease activity, prevention of damage accrual, and mortality. Furthermore, HCQ is thought to protect against accelerated atherosclerosis targeting toll-like receptor signaling, cytokine production, T-cell and monocyte activation, oxidative stress, and endothelial dysfunction. HCQ was also described to have beneficial effects on traditional CV risk factors, such as dyslipidemia and diabetes. In conclusion, despite lacking randomized controlled trials unambiguously proving the protection of HCQ against accelerated atherosclerosis and incidence of CV events in SLE patients, evidence analyzed in this review is in favor of its beneficial effect.

Novel function of hydroxychloroquine: Down regulation of T follicular helper cells in collagen-induced arthritis

Hydroxychloroquine (HCQ) is an immunosuppressive agent widely used in rheumatoid arthritis (RA). T follicular helper (Tfh) cells play a vital role in the pathogenesis of RA. However, whether HCQ suppresses arthritis development through interfering with Tfh cells have never been reported. To address this issue, we investigated the percent of Tfh cells in newly diagnosed RA patients and found that they were up-regulated in peripheral blood. Importantly, in ex vivo experiments of peripheral blood mononuclear cells (PBMCs) from healthy volunteers, we proved that the percentage of Tfh cells in PBMCs and purified CD4⁺ T cells were decreased after HCQ treatment. In in vivo experiments of collagen-induced arthritis (CIA) model, we discovered that HCQ suppressed the incidence and score of arthritis, reduced the secretion of proinflammatory cytokines in serum. Similar to ex vivo study, the ratio of Tfh cells in HCQ treated CIA mice declined to the level of vehicle-treated group. Further research demonstrated that HCQ inhibited the generation of Tfh cells stimulated by IL-12 and IL-21. In conclusion, our study indicates a previously unrecognized mechanism of HCQ in RA, that HCQ directly suppresses the generation of Tfh cells by blocking IL-12 and IL-21 signaling pathways probably.

Ataxia telangiectasia in Turkey: multisystem involvement of 91 patients

BACKGROUND

Ataxia telangiectasia (AT) is a genetically based multisystemic disorder. We aimed to make a comprehensive evaluation of multisystem involvement in AT by describing clinical features and outcome of 91 patients.

METHODS

Medical records of the patients who were diagnosed and followed by a multidisciplinary approach during a 27-year period (1988-2015) were reviewed retrospectively.

RESULTS

Forty six female and 45 male patients with a mean follow-up period of 39.13±4.28 months were evaluated. The mean age at the time of symptom onset and diagnosis were 15.4±1.09 months and 73.61±4.11 months, respectively. Neurological abnormalities were progressive truncal ataxia, nystagmus, dysarthria, oculomotor apraxia and choreoathetosis. Thirty one patients (34.1%) became dependent on wheelchair at a mean age of 12.1±2.8 years. Eleven patients (12.1%) became bedridden by a mean age of 14.7±1.8 years. Cranial magnetic resonance imaging revealed pathological findings in 47/66 patients. Abnormal immunological parameters were determined in 51/91 patients: immunoglobulin (Ig)A deficiency (n=38), lymphopenia (n=30), IgG (n=15) and IgG₂ (n=11) deficiency. Occurrence of recurrent sinopulmonary infections (n=45) and bronchiectasis (n=22) were found to be more common in patients with impaired immunological parameters (P=0.029 and P=0.023, respectively). Malignancy developed in 5 patients, being mostly lymphoreticular in origin and resulted in death of 4 patients.

CONCLUSIONS

AT is a long lasting disease with multisystem involvement necessitating multidisciplinary follow up, as described in our cohort. Early diagnosis of malignancy and supportive treatments regarding pulmonary and neurological health may prolong survival and increase the quality of life.

Factor Xa Mediates Calcium Flux in Endothelial Cells and is Potentiated by Igg From Patients With Lupus and/or Antiphospholipid Syndrome

Factor (F) Xa reactive IgG isolated from patients with antiphospholipid syndrome (APS) display higher avidity binding to FXa with greater coagulant effects compared to systemic lupus erythematosus (SLE) non APS IgG. FXa signalling via activation of protease-activated receptors (PAR) leads to increased intracellular calcium (Ca²⁺). Therefore, we measured alterations in Ca²⁺ levels in human umbilical vein endothelial cells (HUVEC) following FXa-mediated PAR activation and investigated whether FXa reactive IgG from patients with APS or SLE/APS- alter these responses. We observed concentration-dependent induction of Ca²⁺ release by FXa that was potentiated by APS-IgG and SLE/APS- IgG compared to healthy control subjects’ IgG, and FXa alone. APS-IgG and SLE/APS- IgG increased FXa mediated NFκB signalling and this effect was fully-retained in the affinity purified anti-FXa IgG sub-fraction. Antagonism of PAR-1 and PAR-2 reduced FXa-induced Ca²⁺ release. Treatment with a specific FXa inhibitor, hydroxychloroquine or fluvastatin significantly reduced FXa-induced and IgG-potentiated Ca²⁺ release. In conclusion, PAR-1 and PAR-2 are involved in FXa-mediated intracellular Ca²⁺ release in HUVEC and FXa reactive IgG from patients with APS and/or SLE potentiate this effect. Further work is required to explore the potential use of IgG FXa reactivity as a novel biomarker to stratify treatment with FXa inhibitors in these patients.

Hydroxychloroquine inhibits CD154 expression in CD4+ T lymphocytes of systemic lupus erythematosus through NFAT, but not STAT5, signaling

Background

Overexpression of membranous CD154 in T lymphocytes has been found previously in systemic lupus erythematosus (SLE). Because hydroxychloroquine (HCQ) has been used frequently in the treatment of lupus, we sought to identify the effects of HCQ on CD154 and a possibly regulatory mechanism.

Methods

CD4⁺ T cells were isolated from the blood of lupus patients. After stimulation with ionomycin or IL-15 and various concentrations of HCQ, expression of membranous CD154 and NFAT and STAT5 signaling were assessed.

Results

HCQ treatment had significant dose-dependent suppressive effects on membranous CD154 expression in ionomycin-activated T cells from lupus patients. Furthermore, HCQ inhibited intracellular sustained calcium storage release, and attenuated the nuclear translocation of NFATc2 and the expression of NFATc1. However, CD154 expressed through IL-15-mediated STAT5 signaling was not inhibited by HCQ treatment.

Conclusions

HCQ inhibited NFAT signaling in activated T cells and blocked the expression of membranous CD154, but not STAT5 signaling. These findings provide a mechanistic insight into SLE in HCQ treatment.

Hydroxychloroquine retinopathy

Hydroxychloroquine (HCQ; Plaquenil) is used increasingly in the management of a variety of autoimmune disorders, with well established roles in dermatology and rheumatology and emerging roles in oncology. Hydroxychloroquine has demonstrated a survival benefit in patients with systemic lupus erythematosus; some clinicians advocate its use in all such patients. However, Hydroxychloroquine and chloroquine (CQ) have been associated with irreversible visual loss due to retinal toxicity. Hydroxychloroquine retinal toxicity is far more common than previously considered; an overall prevalence of 7.5% was identified in patients taking HCQ for greater than 5 years, rising to almost 20% after 20 years of treatment. This review aims to provide an update on HCQ/CQ retinopathy. We summarise emerging treatment indications and evidence of efficacy in systemic disease, risk factors for retinopathy, prevalence among HCQ users, diagnostic tests, and management of HCQ retinopathy. We highlight emerging risk factors such as tamoxifen use, and new guidance on safe dosing, reversing the previous recommendation to use ideal body weight, rather than actual body weight. We summarise uncertainties and the recommendations made by existing HCQ screening programmes. Asian patients with HCQ retinopathy may demonstrate an extramacular or pericentral pattern of disease; visual field testing and retinal imaging should include a wider field for screening in this group. HCQ is generally safe and effective for the treatment of systemic disease but because of the risk of HCQ retinal toxicity, modern screening methods and ideal dosing should be implemented. Guidelines regarding optimal dosing and screening regarding HCQ need to be more widely disseminated.

Chloroquine inhibits human CD4+ T-cell activation by AP-1 signaling modulation

Chloroquine (CQ) is widely used as an anti-inflammatory therapeutic for rheumatic diseases. Although its modes of action on the innate immune system are well described, there is still insufficient knowledge about its direct effects on the adaptive immune system. Thus, we evaluated the influence of CQ on activation parameters of human CD4⁺ T-cells. CQ directly suppressed proliferation, metabolic activity and cytokine secretion of T-cells following anti-CD3/anti-CD28 activation. In contrast, CQ showed no effect on up-regulation of T-cell activation markers. CQ inhibited activation of all T helper cell subsets, although IL-4 and IL-13 secretion by Th2 cells were less influenced compared to other Th-specific cytokines. Up to 10 μM, CQ did not reduce cell viability, suggesting specific suppressive effects on T-cells. These properties of CQ were fully reversible in re-stimulation experiments. Analyses of intracellular signaling showed that CQ specifically inhibited autophagic flux and additionally activation of AP-1 by reducing phosphorylation of c-JUN. This effect was mediated by inhibition of JNK catalytic activity. In summary, we characterized selective and reversible immunomodulatory effects of CQ on human CD4⁺ T-cells. These findings provide new insights into the biological actions of JNK/AP-1 signaling in T-cells and may help to expand the therapeutic spectrum of CQ.

Chloroquine Suppresses the Development of Hypertension in Spontaneously Hypertensive Rats

BACKGROUND

Innate immune system responses to damage-associated molecular patterns (DAMPs) are involved in hypertension. However, the mechanisms of this contribution are not well understood. Circulating mitochondrial DNA is a DAMP that activates Toll-like receptor (TLR) 9 and is elevated in spontaneously hypertensive rats (SHR). Therefore, we hypothesized that lysosomotropic agent chloroquine (CQ) would impair TLR9 signaling, as well as prevent the development of hypertension and immune cell recruitment to the vasculature, in SHR.

METHODS

Initially, adult SHR and Wistar-Kyoto (WKY) rats (12 weeks old), as well as a group of young SHR (5 weeks old), were treated with CQ (40mg/kg/day) or vehicle (saline) via intraperitoneal injections for 21 days and then TLR9-myeloid differentiation primary response protein (MyD88) signaling proteins were assessed in mesenteric resistance arteries (MRA) via western blot. Subsequently, young SHR and WKY were treated from 5-8 weeks of age and then were allowed to mature without further treatment. Blood pressure was measured pretreatment, posttreatment, and after maturation, and immune cell recruitment to the vasculature was measured via flow cytometry after maturation.

RESULTS

In MRA from adult SHR, CQ increased the expression of MyD88-dependent proteins, whereas young SHR MRA exhibited a decrease. This inhibition was subsequently associated with suppression of blood pressure, as well as decreased counts of circulating T cells and vascular infiltrating leukocytes in SHR, when CQ was administered during the prehypertensive phase.

CONCLUSIONS

These data bring into question the participation of TLRs during the maintenance phase of hypertension and promote the exploration of innate immune system therapy during the critical developmental phase.

Recurrent Kikuchi's Disease Treated by Hydroxychloroquine

Kikuchi-Fujimoto disease (KFD) is a benign, self-limiting disease, with a specific histopathology. It can be diagnosed clinically, and specific symptoms include fever and cervical lymphadenopathy. The histological finding of KFD in cervical lymph nodes includes necrotizing lymphadenitis. KFD needs conservative treatments. If KFD persists for a long period, steroids or nonsteroidal antiinflammatory drugs can be used to control symptoms. Previous studies have reported the treatment of KFD with hydroxychloroquine (HC) in patients unresponsive to steroids. Herein, we report a case of a 25-year-old female patient diagnosed with KFD unresponsive to steroids, and was successfully treated with HC.

The TLR7 agonist imiquimod induces bronchodilation via a nonneuronal TLR7-independent mechanism: a possible role for quinoline in airway dilation

Toll-like receptor (TLR) 7 agonists are known to reduce allergic airway inflammation. Their recently reported ability to rapidly relax airways has further increased their interest in the treatment of pulmonary disease. However, the mechanisms behind this effect are not fully understood. The present study, therefore, aimed to determine whether airway smooth muscle (ASM)-dependent mechanisms could be identified. TLR7 agonists were added to guinea pig airways following precontraction with carbachol in vitro or histamine in vivo. Pharmacological inhibitors were used to dissect conventional pathways of bronchodilation; tetrodotoxin was used or bilateral vagotomy was performed to assess neuronal involvement. Human ASM cells (HASMCs) were employed to determine the effect of TLR7 agonists on intracellular Ca(2+) ([Ca(2+)]i) mobilization. The well-established TLR7 agonist imiquimod rapidly relaxed precontracted airways in vitro and in vivo. This relaxation was demonstrated to be independent of nitric oxide, carbon monoxide, and cAMP signaling, as well as neuronal activity. A limited role for prostanoids could be detected. Imiquimod induced [Ca(2+)]i release from endoplasmic reticulum stores in HASMCs, inhibiting histamine-induced [Ca(2+)]i The TLR7 antagonist IRS661 failed to inhibit relaxation, and the structurally dissimilar agonist CL264 did not relax airways or inhibit [Ca(2+)]i This study shows that imiquimod acts directly on ASM to induce bronchorelaxation, via a TLR7-independent release of [Ca(2+)]i The effect is paralleled by other bronchorelaxant compounds, like chloroquine, which, like imiquimod, but unlike CL264, contains the chemical structure quinoline. Compounds with quinoline moieties may be of interest in the development of multifunctional drugs to treat pulmonary disease.

Impact of Hydroxychloroquine-Loaded Polyurethane Intravaginal Rings on Lactobacilli

The use of polymeric devices for controlled sustained delivery of drugs is a promising approach for the prevention of HIV-1 infection. Unfortunately, certain microbicides, when topically applied vaginally, may be cytotoxic to vaginal epithelial cells and the protective microflora present within the female genital tract. In this study, we evaluated the impact of hydroxychloroquine (HCQ)-loaded, reservoir-type, polyurethane intravaginal rings (IVRs) on the growth of Lactobacillus crispatus and Lactobacillus jensenii and on the viability of vaginal and ectocervical epithelial cells. The IVRs were fabricated using hot-melt injection molding and were capable of providing controlled release of HCQ for 24 days, with mean daily release rates of 17.01 ± 3.6 μg/ml in sodium acetate buffer (pH 4) and 29.45 ± 4.84 μg/ml in MRS broth (pH 6.2). Drug-free IVRs and the released HCQ had no significant effects on bacterial growth or the viability of vaginal or ectocervical epithelial cells. Furthermore, there was no significant impact on the integrity of vaginal epithelial cell monolayers, in comparison with controls, as measured by transepithelial electrical resistance. Overall, this is the first study to evaluate the effects of HCQ-loaded IVRs on the growth of vaginal flora and the integrity of vaginal epithelial cell monolayers.

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.

[Hyper-reactive malarial splenomegaly]

Hyper-reactive malarial splenomegaly is a rare and severe form of chronic malaria. This condition is a common cause of splenomegaly in endemic areas. The pathophysiology of hyper-reactive malarial splenomegaly involves an intense immune reaction (predominantly B cell-driven) to repeated/chronic infections with Plasmodium sp. The diagnosis may be difficult, due to a poorly specific clinical presentation (splenomegaly, fatigue, cytopenias), a long delay between residence in a malaria-endemic area and onset of symptoms, and a frequent absence of parasites on conventional thin and thick blood smears. A strongly contributive laboratory parameter is the presence of high levels of total immunoglobulin M. When the diagnostic of hyper-reactive malarial splenomegaly is considered, search for anti-Plasmodium antibodies and Plasmodium nucleic acids (genus and species) by PCR is useful. Diagnosis of hyper-reactive malarial splenomegaly relies on the simultaneous presence of epidemiological, clinical, biological and follow-up findings. Regression of both splenomegaly and hypersplenism following antimalarial therapy allows the differential diagnosis with splenic lymphoma, a common complication of hyper-reactive malarial splenomegaly. Although rare in Western countries, hyper-reactive malarial splenomegaly deserves increased medical awareness to reduce the incidence of incorrect diagnosis, to prevent progression to splenic lymphoma and to avoid splenectomy.

Autophagosome-lysosome fusion is independent of V-ATPase-mediated acidification

The ATP-dependent proton pump V-ATPase ensures low intralysosomal pH, which is essential for lysosomal hydrolase activity. Based on studies with the V-ATPase inhibitor BafilomycinA1, lysosomal acidification is also thought to be required for fusion with incoming vesicles from the autophagic and endocytic pathways. Here we show that loss of V-ATPase subunits in the Drosophila fat body causes an accumulation of non-functional lysosomes, leading to a block in autophagic flux. However, V-ATPase-deficient lysosomes remain competent to fuse with autophagosomes and endosomes, resulting in a time-dependent formation of giant autolysosomes. In contrast, BafilomycinA1 prevents autophagosome–lysosome fusion in these cells, and this defect is phenocopied by depletion of the Ca²⁺ pump SERCA, a secondary target of this drug. Moreover, activation of SERCA promotes fusion in a BafilomycinA1-sensitive manner. Collectively, our results indicate that lysosomal acidification is not a prerequisite for fusion, and that BafilomycinA1 inhibits fusion independent of its effect on lysosomal pH.

BafilomycinA1 is an autophagy inhibitor, presumably owing to its blocking effect on the lysosomal proton pump V-ATPase. Here the authors show that V-ATPase-deficient lysosomes can still fuse with autophagosomes, showing that lysosomal acidification and fusion are two separable, independent events.

Hydroxychloroquine in children with interstitial (diffuse parenchymal) lung diseases

Hydroxychloroquine (HCQ) is one of the drugs frequently used for the treatment of interstitial lung disease (ILD) in children (chILD). This use is off-label and studies to analyze the effect and safety of HCQ in chILD are lacking. Therefore, a literature research on the usage of chloroquine (CQ) and HCQ in these conditions was done. Eighty-five case reports and small series in the period from 1984 to 2013 were identified in which children with different diagnoses of ILD were treated with CQ or HCQ, sometimes in combination with other medication including steroids. A favorable response to HCQ or CQ was reported in 35 cases, whereas in the other cases the effect was negative or not clear. The dose of HCQ used was between 5 and 10 mg/kg body weight/day (bw/d). No pharmacokinetic studies have been done. The side effect profile in children seemed to be similar to that in adults. Most often gastrointestinal symptoms were reported. Three patients were found developing retinal changes during the treatment with CQ, whereas in none of the patients treated with HCQ retinal changes were reported. Based on retrospective case reports and small series likely to be reported with bias, the use of HCQ in chILD might be classified as safe. As no prospective data on efficacy and safety of HCQ in chILD are available, systematic collection is necessary. This may be achieved by web-based registers like the European Management Platform for Childhood Interstitial Lung Diseases. Prospective and controlled investigations of HCQ in patients with chILD are mandatory.

Influence of quinacrine and chloroquine on the in vitro 3'-azido-3'-deoxythymidine antiretroviral effect

Background

Antimalarials quinacrine (Qc) and chloroquine (Cq) intercalate DNA, potentiate the activity of other drugs and have lysosomotropic, anti-inflammatory and antiviral activities that could increase the effect of the 3′-azido-3′-deoxythymidine (AZT) antiretroviral agent. The aim of the current study was to evaluate if Qc and Cq could improve the in vitro effect of the antiretroviral AZT agent.

Findings

Inhibition of viral replication in human immunodeficiency virus (HIV)_SF33-infected peripheral blood mononuclear cells treated with Qc or Cq, alone or combined with a low dose of AZT was measured. Viral replication increased with Qc and decreased with high doses of Cq. The increase of replication caused by Qc was reversed by AZT. Neither Qc nor Cq significantly changed the antiviral activity of AZT.

Conclusion

Cq does not potentiate the effect of AZT, but it is effective by itself at high doses. The rise of HIV replication by Qc could be deleterious in HIV endemic regions, where it is used as antimalarial. The mechanisms associated to this phenomenon must be identified.

Hydroxychloroquine as an anti-thrombotic in antiphospholipid syndrome

Elective therapeutic approaches are required since recurrent thrombosis remains a major challenge in the management of antiphospholipid syndrome (APS) despite an efficient anticoagulation. Several data suggest that hydroxychloroquine (HCQ) could play a role in the prevention of thrombosis. The goal of this review is to point out the different aspects that could suggest the usefulness and the efficacy of HCQ for the prevention of thrombosis relapse in APS. By Medline research we collected important data dealing with potential anti-thrombotic effects of HCQ. The mechanisms of action of HCQ, and clinical and experimental data in systemic lupus erythematosus (SLE) and APS are discussed. As HCQ reduces the risk of thrombosis in both SLE patients and animal models of APS (1-7), and possibly decreases the titre of aPL [8], its beneficial role as a potential antithrombotic could be suggested.

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.

Therapeutic potential of chloroquine in a murine model of inflammatory bowel disease

Inflammatory bowel disease (IBD) is an idiopathic chronic inflammation of the gastrointestinal tract which is mainly caused by dysregulated gut immune response to commensal flora. Very limited treatment options with marginal efficacy are available along with surgery which has high risk of reoccurrence. As both innate and adaptive immune responses have been found altered in IBD, a good therapeutic strategy could be to restrict both of them under chronic inflammatory conditions. Effect of chloroquine on TLR9 signaling is well reported, while there are limited studies on non-endosomal TLRs as well as T cell responses. Hence, we studied its effect on other TLRs as well as T cell response along with testing it as a potential therapeutics in IBD using murine preclinical colitis model. Chloroquine significantly suppressed the TLR2 as well as TLR9 signaling in both in vitro as well as in vivo experimental settings, while it had no effect on TLR4 pathway. It also suppressed the T cell cytokine and proliferative responses. In, DSS-induced murine colitis model, chloroquine administration, significantly improved body weight loss, colon length shortening, tissue damage and inflammatory cell infiltration. Based on our findings in preclinical murine model of IBD, chloroquine has the potential to be considered as a therapeutic option in clinics through inhibition of diverse TLR and T cell responses.

Hydroxychloroquine: a multifaceted treatment in lupus

The efficacy of antimalarials, especially hydroxychloroquine (HCQ), in preventing systemic lupus erythematosus (SLE) flares is well demonstrated. However, many studies show that the percentage of SLE patients treated with HCQ remains low. By blocking the toll-like receptor 7 and 9 in plasmacytoid dendritic cells, HCQ inhibits interferon-alpha production which plays a crucial role in SLE pathogenesis. In addition to reducing damage accrual in SLE patients, HCQ appears to protect against the occurrence of diabetes, thrombotic events, and dyslipidemia. As a consequence, some studies have suggested that HCQ, which is inexpensive, has a protective effect on survival in SLE patients. Thanks to the pharmacokinetic properties of HCQ (long half-life) and to the availability of its blood assay, very low or undetectable blood HCQ concentrations are a valuable marker of non-adherence to treatment, thus adding a new benefit to HCQ prescriptions. The main side effect of HCQ is retinal toxicity. This complication is very rare, but may be potentially severe, thus requiring regular screening. Retinal toxicity remains the only absolute contra-indication of HCQ in adult SLE patients. Other contra-indications are few and rare. During pregnancy and breast-feeding, HCQ continuation is not only allowed but recommended. In conclusion, the risk/benefit ratio of HCQ is excellent. Many now believe that all SLE patients should be offered this treatment.

Ten-year follow up of hydroxychloroquine treatment for ABCA3 deficiency

We present a child with interstitial lung disease (ILD) who was diagnosed with desquamative interstitial pneumonitis following CT thorax and open lung biopsy aged 2 years. Subsequently, surfactant protein gene analysis revealed mutations in the ABCA3 gene. This case of ABCA3 deficient ILD describes a stable clinical course over 10 years and highlights the potential benefit of hydroxychloroquine for this condition.

Dendritic cells treated with chloroquine modulate experimental autoimmune encephalomyelitis

Chloroquine (CQ), an antimalarial drug, has been shown to modulate the immune system and reduce the severity of experimental autoimmune encephalomyelitis (EAE). The mechanisms of disease suppression are dependent on regulatory T cell induction, although Tregs-independent mechanisms exist. We aimed to evaluate whether CQ is capable to modulate bone marrow-derived dendritic cells (DCs) both phenotypically and functionally as well as whether transfer of CQ-modulated DCs reduces EAE course. Our results show that CQ-treated DCs presented altered ultrastructure morphology and lower expression of molecules involved in antigen presentation. Consequently, T cell proliferation was diminished in coculture experiments. When transferred into EAE mice, DC-CQ was able to reduce the clinical manifestation of the disease through the modulation of the immune response against neuroantigens. The data presented herein indicate that chloroquine-mediated modulation of the immune system is achieved by a direct effect on DCs and that DC-CQ adoptive transfer may be a promising approach for avoiding drug toxicity.

Chloroquine: modes of action of an undervalued drug

For more than two decades, chloroquine (CQ) was largely and deliberately used as first choice drug for malaria treatment. However, worldwide increasing cases of resistant strains of Plasmodium have hampered its use. Nevertheless, CQ has recently been tested as adjunct therapy in several inflammatory situations, such as rheumatoid arthritis and transplantation procedures, presenting intriguing and promising results. In this review, we discuss recent findings and CQ mechanisms of action vis-à-vis its use as a broad adjunct therapy.

Understanding and controlling chronic immune activation in the HIV-infected patients suppressed on combination antiretroviral therapy

Combination antiretroviral therapy (cART) has resulted in tremendous gains in survival among HIV-infected patients, but as a group those who achieve undetectable viral loads on cART experience a greater degree of immune activation and inflammation than the general population. HIV-infected patients continue to experience premature immune senescence with earlier and more frequent non-AIDS events compared to HIV-uninfected individuals. Chronic immune activation during suppressive cART derives from a variety of sources mediated by cytokines, chemokines, coagulation, microbial translocation, immune regulators and T(effector) cell activation abnormalities, among others. Current investigational strategies to control immune activation target potential causes of persistently heightened immune activation during cART such as microbial translocation, co-infections, and comorbidities or mediators along a common final pathway. Although several interventions have shown promise in vitro or in preliminary clinical trials, no intervention has sufficient evidence for routine use, making control of immune activation during cART an unmet need.

Multifaceted effects of hydroxychloroquine in human disease

OBJECTIVES

Hydroxychloroquine (HCQ) is a widely used medication for the treatment of rheumatoid arthritis and systemic lupus erythematosus. An increasing body of evidence supports actions of this drug that are not directly related to its immunosuppressive or anti-rheumatic properties. The objective of this systematic review is to characterize the spectrum of conditions that might be responsive to treatment with HCQ.

METHODS

PubMed was searched using the MeSH for HCQ with relevant subheadings and the limits of human topics and English language. Four-hundred and fifty-six abstracts from this search were examined individually to exclude those that were not focused on the objectives of this review. The resulting 76 articles were grouped according to topic areas and reviewed in detail.

RESULTS

HCQ has been reported to have therapeutic effects in a wide array of conditions, including diabetes mellitus, dyslipidemias, coagulopathies, infectious diseases and malignancies. Mechanisms of action responsible for these effects likely include altered signaling through cellular receptors, post-glycosylation modifications of infectious agents, changes in levels of inflammatory mediators and inhibition of autophagy. Many of the pathways are likely dependent on drug-induced changes in intra-endosomal acidity.

CONCLUSIONS

The use of, and interest in, HCQ has spread into many areas of medicine. Actions of this drug may be directly beneficial to patients with non-rheumatic conditions such as diabetes mellitus or viral infections. Further understanding of underlying mechanisms has potential to reveal modifiable pathogenic pathways that might elucidate approaches to the design of more effective therapeutics for many chronic diseases.

Hydroxychloroquine effectiveness in reducing symptoms of hand osteoarthritis (HERO): study protocol for a randomized controlled trial

Background

Osteoarthritis (OA) is the most common type of arthritis, causing significant joint pain and disability. It is already a major cause of healthcare expenditure and its incidence will further increase with the ageing population. Current treatments for OA have major limitations and new analgesic treatments are needed. Synovitis is prevalent in OA and is associated with pain. Hydroxychloroquine is used in routine practice for treating synovitis in inflammatory arthritides, such as rheumatoid arthritis. We propose that treating patients with symptomatic hand OA with hydroxychloroquine will be a practical and safe treatment to reduce synovitis and pain.

Methods/design

HERO is an investigator-initiated, multicentre, randomized, double-blind, placebo-controlled trial. A total of 252 subjects with symptomatic hand OA will be recruited across primary and secondary care sites in the UK and randomized on a 1:1 basis to active treatment or placebo for 12 months. Daily medication dose will range from 200 to 400 mg according to ideal body weight. The primary endpoint is change in average hand pain during the previous two weeks (measured on a numerical rating scale (NRS)) between baseline and six months. Secondary endpoints include other self-reported pain, function and quality-of-life measures and radiographic structural change at 12 months. A health economics analysis will also be performed. An ultrasound substudy will be conducted to examine baseline levels of synovitis. Linear and logistic regression will be used to compare changes between groups using univariable and multivariable modelling analyses. All analyses will be conducted on an intention-to-treat basis.

Discussion

The HERO trial is designed to examine whether hydroxychloroquine is an effective analgesic treatment for OA and whether it provides any long-term structural benefit. The ultrasound substudy will address whether baseline synovitis is a predictor of therapeutic response. This will potentially provide a new treatment for OA, which could be of particular use in the primary care setting.

Trial registration

ISRCTN91859104.

Enhancement of T cell-mediated immune responses to whole inactivated influenza virus by chloroquine treatment in vivo

Current influenza vaccines induce poor cross-reactive CD8+ T cell responses. Cellular immunity is generally specific for epitopes that are remarkably conserved among different subtypes, suggesting that strategies to improve the cross-presentation of viral antigens by dendritic cells (DC) could elicit a broadly protective immune response. Previous studies have shown that limited proteolysis within the endocytic pathway can favorably influence antigen processing and thus immune responses. Herein, we demonstrate that chloroquine improves the cross-presentation of non-replicating influenza virus in vitro and T cell responses in mice following a single administration of inactivated HI-X31 virus. CD8+ T cells were also recruited to lymph nodes draining the site of infection and able to reduce viral load following pulmonary challenge with the heterologous PR8 virus. These findings may have implications for vaccination strategies aimed at improving the cross-presentation capacity of DCs and thus the size of effector and memory CD8+ T cells against influenza vaccines.

[Conventional basis therapy of rheumatoid arthritis. Effects within and outside cells]

Conventional disease-modifying antirheumatic drugs (DMARDs) were formerly introduced into the treatment of rheumatoid arthritis and other rheumatic disorders on an empirical basis. In many cases their mode of action is only partially understood but as a rule of thumb they act on more than one point within the cellular metabolism. Less often they exert biological effects in the extracellular space or on the cell membrane.

Hydroxychloroquine: from malaria to autoimmunity

Quinine was first recognized as a potent antimalarial agent hundreds of years ago. Since then, the beneficial effects of quinine and its more advanced synthetic forms, chloroquine and hydroxychloroquine, have been increasingly recognized in a myriad of other diseases in addition to malaria. In recent years, antimalarials were shown to have various immunomodulatory effects, and currently have an established role in the management of rheumatic diseases, such as systemic lupus erythematosus and rheumatoid arthritis, skin diseases, and in the treatment of chronic Q fever. Lately, additional metabolic, cardiovascular, antithrombotic, and antineoplastic effects of antimalarials were shown. In this review, we discuss the known various immunomodulatory mechanisms of antimalarials and the current evidence for their beneficial effects in various diseases and in potential novel applications.

Effect of hydroxychloroquine treatment on pro-inflammatory cytokines and disease activity in SLE patients: data from LUMINA (LXXV), a multiethnic US cohort

OBJECTIVE

We sought to determine the effect of hydroxychloroquine therapy on the levels proinflammatory/prothrombotic markers and disease activity scores in patients with systemic lupus erythematosus (SLE) in a multiethnic, multi-center cohort (LUMINA).

METHODS

Plasma/serum samples from SLE patients (n = 35) were evaluated at baseline and after hydroxychloroquine treatment. Disease activity was assessed using SLAM-R scores. Interferon (IFN)-α2, interleukin (IL)-1β, IL-6, IL-8, inducible protein (IP)-10, monocyte chemotactic protein-1, tumor necrosis factor (TNF)-α and soluble CD40 ligand (sCD40L) levels were determined by a multiplex immunoassay. Anticardiolipin antibodies were evaluated using ELISA assays. Thirty-two frequency-matched plasma/serum samples from healthy donors were used as controls.

RESULTS

Levels of IL-6, IP-10, sCD40L, IFN-α and TNF-α were significantly elevated in SLE patients versus controls. There was a positive but moderate correlation between SLAM-R scores at baseline and levels of IFN-α (p = 0.0546). Hydroxychloroquine therapy resulted in a significant decrease in SLAM-R scores (p = 0.0157), and the decrease in SLAM-R after hydroxychloroquine therapy strongly correlated with decreases in IFN-α (p = 0.0087).

CONCLUSIONS

Hydroxychloroquine therapy resulted in significant clinical improvement in SLE patients, which strongly correlated with reductions in IFN-α levels. This indicates an important role for the inhibition of endogenous TLR activation in the action of hydroxychloroquine in SLE and provides additional evidence for the importance of type I interferons in the pathogenesis of SLE. This study underscores the use of hydroxychloroquine in the treatment of SLE.

Hydroxychloroquine reduces binding of antiphospholipid antibodies to syncytiotrophoblasts and restores annexin A5 expression

OBJECTIVE

Antibody-mediated disruption of the annexin A5 anticoagulant shield has been posited to be a thrombogenic mechanism in the antiphospholipid syndrome. We recently showed that the antimalarial drug, hydroxychloroquine, dissociates antiphospholipid immune complexes and restores annexin A5 binding to planar phospholipid bilayer. Using quantitative immunoassays, we demonstrated similar effects on BeWo trophoblasts. We therefore, investigated the effects of the drug on localization of annexin A5 in primary cultures of human placental syncytiotrophoblasts.

STUDY DESIGN

Laser confocal microscopy with computer-based morphometric analysis was used to localize annexin A5 and antiphospholipid antibodies on syncytiotrophoblasts exposed to polyclonal and monoclonal antiphospholipid and control immunoglobulin-Gs.

RESULTS

Hydroxychloroquine reversed the effects of the antiphospholipid antibodies on the syncytiotrophoblasts by markedly reducing immunoglobulin-G binding and restoring annexin A5 expression.

CONCLUSION

These results provide the first morphologic evidence for this effect of hydroxychloroquine on human placental syncytiotrophoblasts and support the possibility of novel treatments that target antiphospholipid antibody binding.

Hydroxychloroquine use and decreased risk of diabetes in rheumatoid arthritis patients

BACKGROUND/OBJECTIVES

Several studies have associated hydroxychloroquine use with decreased risk of diabetes mellitus (diabetes) or improved glycemic control in rheumatoid arthritis patients, but the studies were small or used data from self-report. The present study sought to replicate this protective relationship in a health system using electronic health records with laboratory data and physician diagnoses.

METHODS

This study is a retrospective cohort of 1127 adults with newly diagnosed rheumatoid arthritis and no diabetes within the Geisinger Health System between January 1, 2003, and March 31, 2008. Patients were classified as ever users (n = 333) or never users (n = 794) of hydroxychloroquine. Incident diabetes cases were defined using 2010 American Diabetes Association criteria.

RESULTS

The median follow-up times for the ever and never hydroxychloroquine users were 26.0 and 23.0 months, respectively (P = 0.28). The median duration of hydroxychloroquine exposure was 14.0 months. Of the 48 cases developing diabetes during observation, 3 were exposed to hydroxychloroquine at time of development and 45 were nonexposed, yielding incidence rates of 6.2 and 22.0 per 1000 per year (P = 0.03), respectively. In time-varying Cox proportional hazards regression models adjusting for sex, age, body mass index, positive rheumatoid factor and anti-cyclic citrullinated peptide antibodies, erythrocyte sedimentation rate, and nonsteroidal anti-inflammatory drug, glucocorticoid, methotrexate, and tumor necrosis factor α inhibitor use, the hazard ratio for incident diabetes among hydroxychloroquine users was 0.29 (95% confidence interval, 0.09-0.95; P = 0.04) compared with nonusers.

CONCLUSIONS

Our findings support the potential benefit of hydroxychloroquine in attenuating the risk of diabetes in rheumatoid arthritis patients. Further work is needed to determine its potential preventive role in other groups at high risk for diabetes.

Randomized trial of hydroxychloroquine for newly diagnosed chronic graft-versus-host disease in children: a Children's Oncology Group study

The Children's Oncology Group conducted a multicenter Phase III trial for chronic graft-versus-host disease (cGVHD). The double-blind, placebo-controlled, randomized study evaluated hydroxychloroquine added to standard therapy for children with newly diagnosed cGVHD. The study also used a novel grading and response scoring system and evaluated clinical laboratory correlates of cGVHD. The primary endpoint was complete response (CR) after 9 months of therapy. Fifty-four patients (27 on each arm) were enrolled before closure because of slow accrual. The CR rate was 28% in the hydroxychloroquine arm versus 33% in the placebo arm (odds ratio [OR] = 0.77, 95% confidence interval [CI]: 0.20-2.93, P = .75) for 42 evaluable patients. For 41 patients with severity assessment at enrollment, 20 (49%) were severe and 18 (44%) moderate according to the National Institutes of Health Consensus Conference global scoring system. The CR rate was 15% for severe cGVHD and 44% for moderate cGVHD (OR = 0.24, 95% CI: 0.05-1.06, P = .07). Although the study could not resolve the primary question, it provided important information for future cGVHD study design in this population.

Diabetes mellitus and insulin resistance in patients with rheumatoid arthritis: risk reduction in a chronic inflammatory disease

OBJECTIVE

To perform a systematic literature review of the potential association among molecular markers of inflammation, alterations in body composition, and insulin resistance (IR), a precursor to type 2 diabetes mellitus (DM), in rheumatoid arthritis (RA) patients. To determine the impact of tumor necrosis factor α (TNFα) as a pivotal proinflammatory cytokine in the pathophysiology of type 2 DM and RA, and the effect of antirheumatic drugs on glycemic control.

METHODS

We performed a search of PubMed to identify articles on IR and body habitus in patients with RA.

RESULTS

Patients with RA had characteristics placing them at high risk for IR and type 2 DM. The incidence and prevalence of type 2 DM in RA was not clearly increased compared with the general population; however, studies suggested that patients with RA are likely to have IR and have increased risk of cardiovascular disease (CVD). The prevalence of type 2 DM and IR could be estimated from reports of risk factors for CVD in RA patients. The TNFα antagonists provided rapid and effective control of RA-related inflammation. Evidence indicated that extended use of TNFα antagonists in RA may provide the additional benefit of improving insulin sensitivity. These treatment-related changes may contribute to an overall reduction in the risk of type 2 DM and CVD in RA patients.

CONCLUSION

Controlling inflammation may improve insulin sensitivity and subsequently reduce the risk of developing type 2 DM in RA patients. This may also reduce the risk of CVD in this high-risk group. Future studies are required to elucidate the relationships between inflammation, body composition, IR, TNFα antagonist use, and the risk of developing type 2 DM in RA patients.

Use of hydroxychloroquine to prevent thrombosis in systemic lupus erythematosus and in antiphospholipid antibody-positive patients

Hydroxychloroquine is used extensively in the treatment of systemic lupus erythematosus, not only for its benefit for cutaneous and musculoskeletal lupus, but also for its role in preventing flares, preventing renal and central nervous system lupus, and improving survival rates. Hydroxychloroquine also has known benefits in reducing some traditional cardiovascular risk factors, such as hyperlipidemia and diabetes mellitus. This article reviews its possible role as an antithrombotic drug in the general population, in systemic lupus erythematosus, and in patients with antiphospholipid antibodies.

Antiphospholipid syndrome treatment beyond anticoagulation: are we there yet?

Persistently positive antiphospholipid antibodies in association with thromboses and/or pregnancy morbidity is the hallmark of the antiphospholipid syndrome. The management of antiphospholipid antibody-positive patients has been focused on utilizing anti-thrombotic medications such as heparin or warfarin. Given that our understanding of the molecular mechanisms of antiphospholipid antibody-mediated thrombosis has been growing, it is highly likely that the current ‘anti-thrombotic’ approach to these patients will be replaced by an ‘immunomodulatory’ approach in the near future. This review article will address the experimental and/or clinical evidence behind some of these potential ‘immunomodulatory’ approaches (tissue factor inhibition, P38 mitogen-activated protein kinase inhibition, nuclear factor-κB inhibition, platelet glycoprotein receptor inhibition, hydroxychloroquine, statins, inhibition of β2GPI and/or anti-β2GPI binding to target cells, complement inhibition, and B cell inhibition) in antiphospholipid syndrome.

Short communication: preferential concentration of hydroxychloroquine in adenoid tissue of HIV-infected subjects

Hydroxychloroquine (HCQ) anti-HIV activity is well documented. To evaluate its distribution in lymphoid tissues, which are considered sanctuaries of HIV reservoirs and targets of early massive depletion of CD4(+) T cells, we assessed HCQ concentrations in adenoid tissue and plasma of HIV-infected subjects. A daily oral dose of 400 or 800 mg of HCQ was administered to eight HIV-infected subjects for 8 days. HCQ concentrations were measured in plasma and adenoid tissue by high-performance liquid chromatography. Mean concentrations of HCQ in adenoid tissue of subjects treated with 400 and 800 mg were 87,210 +/- 17,817 and 167,472 +/- 93,793 ng/g, respectively. In plasma, these values corresponded to 329 +/- 133 and 278 +/- 68 ng/g, respectively. HCQ concentrations were significantly higher in adenoid tissue than in plasma in both groups. The potential use of HCQ as adjuvant in the therapy of HIV deserves to be explored, as the drug accumulates in relevant tissues for HIV replication and immunopathogenesis.

Therapeutic alternatives for chronic urticaria: an evidence-based review, part 1

OBJECTIVE

To evaluate the use of alternative therapies for chronic urticaria refractory to first-line treatments in an evidence-based manner.

DATA SOURCES

MEDLINE searches were performed cross-referencing urticaria with the names of multiple therapies. Articles were then reviewed for additional citations. Articles published after 1950 were considered.

STUDY SELECTION

All articles, including case reports, were reviewed for soundness and relevance.

RESULTS

Experience has been reported for a wide variety of alternative therapies in the treatment of chronic idiopathic and physical urticarias. Evidence for most agents is limited to anecdotal reports. The second-line therapies reviewed are also categorized based on criteria of safety, efficacy, convenience, and cost, in relation to the first-line antihistamines.

CONCLUSIONS

Alternative agents should be considered in patients with chronic urticaria who are both severely affected and unresponsive to antihistamines. Although monitoring for toxicity is important in management with many alternative agents, safety is favorable compared with corticosteroids.

Hydroxychloroquine directly reduces the binding of antiphospholipid antibody-beta2-glycoprotein I complexes to phospholipid bilayers

Treatment with the antimalarial drug hydroxychloroquine (HCQ) has been associated with reduced risk of thrombosis in the antiphospholipid (aPL) syndrome (APS) and, in an animal model of APS, with reduction of experimentally induced thrombosis. Recognition of beta2-glycoprotein I (beta2GPI) by aPL antibodies appears to play a major role in the disease process. We therefore used the techniques of ellipsometry and atomic force microscopy (AFM) to investigate whether HCQ directly affects the formation of aPL IgG-beta2GPI complexes on phospholipid bilayers. HCQ, at concentrations of 1 mug/mL and greater, significantly reduced the binding of aPL-beta2GPI complexes to phospholipid surfaces and THP-1 (human acute monocytic leukemia cell line) monocytes. The drug also reduced the binding of the individual proteins to bilayers. This HCQ-mediated reduction of binding was completely reversed when the HCQ-protein solutions were dialyzed against buffer. HCQ also caused modest, but statistically significant, reductions of clinical antiphospholipid assays. In conclusion, HCQ reduces the formation of aPL-beta2GPI complexes to phospholipid bilayers and cells. This effect appears to be due to reversible interactions between HCQ and the proteins and may contribute to the observed reduction of thrombosis in human and experimental APS. These results support the possibility that HCQ, or analogous molecules, may offer novel nonanticoagulant therapeutic strategies for treating APS.