Minocycline and doxycycline therapy in community patients with rheumatoid arthritis: prescribing patterns, patient-level determinants of use, and patient-reported side effects

Eravacycline, the first four years: health outcomes and tolerability data for 19 hospitals in 5 U.S. regions from 2018 to 2022

IMPORTANCE

The rise of multidrug-resistant (MDR) pathogens, especially MDR Gram-negatives, poses a significant challenge to clinicians and public health. These resilient bacteria have rendered many traditional antibiotics ineffective, underscoring the urgency for innovative therapeutic solutions. Eravacycline, a broad-spectrum fluorocycline tetracycline antibiotic approved by the FDA in 2018, emerges as a promising candidate, exhibiting potential against a diverse array of MDR bacteria, including Gram-negative, Gram-positive, anaerobic strains, and Mycobacterium. However, comprehensive data on its real-world application remain scarce. This retrospective cohort study, one of the largest of its kind, delves into the utilization of eravacycline across various infectious conditions in the USA during its initial 4 years post-FDA approval. Through assessing clinical, microbiological, and tolerability outcomes, the research offers pivotal insights into eravacycline's efficacy in addressing the pressing global challenge of MDR bacterial infections.

Immunomodulatory roles of metalloproteinases in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, autoimmune pathology characterized by persistent synovial inflammation and gradually advancing bone destruction. Matrix metalloproteinases (MMPs), as a family of zinc-containing enzymes, have been found to play an important role in degradation and remodeling of extracellular matrix (ECM). MMPs participate in processes of cell proliferation, migration, inflammation, and cell metabolism. A growing number of persons have paid attention to their function in inflammatory and immune diseases. In this review, the details of regulation of MMPs expression and its expression in RA are summarized. The role of MMPs in ECM remodeling, angiogenesis, oxidative and nitrosative stress, cell migration and invasion, cytokine and chemokine production, PANoptosis and bone destruction in RA disease are discussed. Additionally, the review summarizes clinical trials targeting MMPs in inflammatory disease and discusses the potential of MMP inhibition in the therapeutic context of RA. MMPs may serve as biomarkers for drug response, pathology stratification, and precision medicine to improve clinical management of rheumatoid arthritis.

Safety of Longer-Term Doxycycline Use: A Systematic Review and Meta-Analysis With Implications for Bacterial Sexually Transmitted Infection Chemoprophylaxis

BACKGROUND

Sexually transmitted infections (STIs) such as syphilis, gonorrhea, and chlamydia have significantly increased over the past decade in the United States. Doxycycline as chemoprophylaxis (i.e., postexposure prophylaxis) offers promise for addressing bacterial STIs. The goal of the current study was to evaluate the safety of longer-term doxycycline use (defined as 8 or more weeks) in the context of potential use as STI chemoprophylaxis through a systematic literature review and meta-analysis.

METHODS

This review used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to search MEDLINE/PubMed for clinical studies published from August 2003 to January 2023 that reported on adverse events with doxycycline use with a focus on side effects and metabolic effects of long-term use.

RESULTS

A total of 67 studies were included in the systematic review. Overall, studies on longer-term doxycycline use reported 0% to greater than 50% adverse events ranging from mild to severe. Most common adverse events included gastrointestinal symptoms (i.e., nausea, vomiting, and abdominal pain), dermatologic (i.e., rash), and neurological (i.e., headache and dizziness) symptoms. Discontinuation of doxycycline due to adverse events was relatively uncommon in most studies. A meta-analysis of placebo controlled clinical trials (N = 18) revealed that gastrointestinal and dermatological adverse events were more likely to occur in the doxycycline group.

CONCLUSIONS

Longer-term (8+ weeks) doxycycline use is generally safe and may be associated with minor side effects. Further research is needed on the potential metabolic impact of longer-term doxycycline use.

Preparation of Novel Nanoformulation to Enhance Efficacy in the Treatment of Cardiovascular Disease

Despite many efforts over the last few decades, cardiac-based drug delivery systems are experiencing major problems, such as the effective delivery of the precise amount of a drug. In the current study, an effort has been made to prepare a nano-herbformulation (NHF) to overcome the major problem of conventional intervention. Copper oxide-based NHF was prepared using plant extract of Alternanthera sessilis and characterized using physicochemical techniques such as Transmission electron microscopy (TEM), X-ray powder diffraction (XRD), Dynamic light scattering (DLS), UV-Vis spectroscopy, and Fourier-transform infrared spectroscopy (FTIR). TEM analysis revealed that spherical NHF obtained of size 20-50 nm. In addition, XRD and FTIR confirmed the presence of phytochemicals with biological properties over the surface of copper oxide-based NHF. It was demonstrated that dose-dependent antiapoptotic activity was shown against DOX-induced cardiomyocytes, where ROS levels were significantly reduced to 0.29% from 37.99%. The results of the flow cytometry analysis using PI and Annexin staining further confirmed the antiapoptotic activity of NHF against DOX-induced cardiomyocytes by ROS scavenging. Thus, NHF might be used for cardiovascular disease treatment.

Phosphorylation at Ser 727 Increases STAT3 Interaction with PKCε Regulating Neuron–Glia Crosstalk via IL-6-Mediated Hyperalgesia In Vivo and In Vitro

Methods

A rat hyperalgesia model was induced using an intraplantar injection of Freund's complete adjuvant (FCA) or an intrathecal injection of IL-6. Mechanical allodynia was evaluated using von Frey filament tests after intrathecal injections of T-5224 (c-Fos/AP-1 inhibitor), minocycline (Mino, a specific microglia inhibitor), L-2-aminoadipic acid (LAA, an astroglial toxin), PKCε inhibitor peptide, APTSTAT3-9R (STAT3 inhibitor), or anti-IL-6 antibody. The c-Fos, GFAP, Iba-1, PKCε, STAT3, pSTAT3^Tyr705 and pSTAT3^Ser727, and IL-6 expression at the spinal cord level was assessed by Western blot analysis. The interactive effects of PKCε and STAT3 were determined using immunofluorescence staining and immunoprecipitation in vivo and in vitro. Interleukin-6 promoter activity was examined using luciferase assays.

Results

T-5224, Mino, and LAA attenuated FCA- or IL-6-mediated inflammatory pain, with a decrease in c-Fos, GFAP, Iba-1, PKCε, and IL-6 expression. PKCε inhibitor peptide and APTSTAT3-9R reversed FCA-induced nociceptive behavior, while decreasing pSTAT3^Ser727, IL-6, c-Fos, GFAP, and Iba-1 expression and PKCε and STAT3 coexpression. Interleukin-6 promoter activity increased in the presence of PKCε and STAT3. The interaction with PKCε increased on phosphorylating STAT3 at Ser727 but not at Tyr705.

Conclusion

STAT3 phosphorylation at Ser 727 and the interaction with PKCε contribute to hyperalgesia via the IL-6-mediated signaling pathway, thus regulating neuron–glia crosstalk during inflammatory pain.

Dysbiosis From a Microbial and Host Perspective Relative to Oral Health and Disease

The significance of microbiology and immunology with regard to caries and periodontal disease gained substantial clinical or research consideration in the mid 1960's. This enhanced emphasis related to several simple but elegant experiments illustrating the relevance of bacteria to oral infections. Since that point, the understanding of oral diseases has become increasingly sophisticated and many of the original hypotheses related to disease causality have either been abandoned or amplified. The COVID pandemic has reminded us of the importance of history relative to infectious diseases and in the words of Churchill "those who fail to learn from history are condemned to repeat it." This review is designed to present an overview of broad general directions of research over the last 60 years in oral microbiology and immunology, reviewing significant contributions, indicating emerging foci of interest, and proposing future directions based on technical advances and new understandings. Our goal is to review this rich history (standard microbiology and immunology) and point to potential directions in the future (omics) that can lead to a better understanding of disease. Over the years, research scientists have moved from a position of downplaying the role of bacteria in oral disease to one implicating bacteria as true pathogens that cause disease. More recently it has been proposed that bacteria form the ecological first line of defense against "foreign" invaders and also serve to train the immune system as an acquired host defensive stimulus. While early immunological research was focused on immunological exposure as a modulator of disease, the "hygiene hypothesis," and now the "old friends hypothesis" suggest that the immune response could be trained by bacteria for long-term health. Advanced "omics" technologies are currently being used to address changes that occur in the host and the microbiome in oral disease. The "omics" methodologies have shaped the detection of quantifiable biomarkers to define human physiology and pathologies. In summary, this review will emphasize the role that commensals and pathobionts play in their interaction with the immune status of the host, with a prediction that current "omic" technologies will allow researchers to better understand disease in the future.

Crossing the barriers: Revisiting the gut feeling in rheumatoid arthritis

To avoid autoimmunity, it is essential to keep the balance between the defence against pathogens and the maintenance of tolerance to self-antigens. Mucosal inflammation may lead to breakdown of tolerance and activation of autoreactive cells. Growing evidence suggests a major contribution of gut microbiota to the onset of chronic, autoimmune inflammatory diseases including rheumatoid arthritis (RA). RA patients show significant differences in the composition of gut microbiota compared to healthy controls, and in murine arthritis models certain bacteria can induce inflammatory Th17 responses or autoantibody production. The gut microbiota plays an important role in regulating the balance between immunogenic and tolerogenic immune responses. The intestinal barrier is the site of the body where most host-microbiota interaction takes place. Certain microbiota or their metabolites can cause a break in homeostasis by affecting the intestinal barrier integrity and permeability. However, an intact intestinal barrier is essential to separate the intestinal epithelium from toxins, microorganisms, and antigens in the gut lumen. This review will focus on the correlation between a leaky gut and the onset of arthritis. Furthermore, it will be discussed how targeting the intestinal barrier function by dietary changes might provide an opportunity to modulate the development of RA.

Efficacy of doxycycline as a combination therapy in the treatment of rheumatoid arthritis: a randomized controlled clinical trial

Background

This single-center randomized open-label clinical trial evaluates the effectiveness of doxycycline as a combination therapy for active rheumatoid arthritis (RA) with methotrexate (MTX).

Materials and methods

One hundred and sixty RA patients were recruited who fulfilled the 2010 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) classification criteria. Subjects were randomly allocated in a 1:1 ratio into one of two treatment arms; one group was maintained on MTX alone and the other group on MTX together with doxycycline orally 200 mg daily. Follow-up clinical response, erythrocyte sedimentation rate (ESR), levels of C-reactive protein (CRP), and disease activity score 28 (DAS28-CRP) after 3 months were done.

Results

There was a significant difference regarding DAS28-CRP between the two groups (median (IQR) 4.26 (3.6–5) for those treated with MTX alone compared with 2.8 (2.37–3.5) for those treated with MTX together with doxycycline) (p = 0.005). A higher number of patients treated with doxycycline in combination with MTX achieved remission (40.5%) compared to patients who received MTX alone (13.5%). The levels of ESR and CRP were lower in patients treated with MTX and doxycycline and this was statistically significant (p = 0.005, p = 0.003 respectively).

Conclusion

Doxycycline as a cost-effective combination therapy with MTX can achieve higher rates of remission than MTX alone in RA patients without causing increase in the adverse events profile.

Trial registration

Clinical Trials.gov, NCT03194204. Registered on 21 June 2017

Minocycline for symptom reduction during radiation therapy for head and neck cancer: a randomized clinical trial

PURPOSE

Local/systemic symptoms during cancer therapy may be exacerbated by dysregulated inflammation and its downstream toxic effects. Minocycline can suppress proinflammatory cytokine release; therefore, we investigated its potential to reduce patient-reported symptom severity during radiotherapy (RT) for head and neck cancer (HNC).

METHODS

Eligible patients for this blinded, placebo-controlled trial were adults with T0-3, N-any, and M0 HNC receiving single-modality RT. Participants were randomized 1:1 to either minocycline (200 mg/day) or placebo during RT. The primary endpoint was the area under the curve (AUC) of 5 prespecified symptoms (pain, fatigue, disturbed sleep, poor appetite, difficulty swallowing/chewing) during RT, assessed with the MD Anderson Symptom Inventory for HNC (MDASI-HN).

RESULTS

We analyzed data from 20 evaluable patients per arm. Overall, 75% had oropharyngeal cancer and 78% were male. No grade 3+ adverse events potentially related to study medication were observed. Two minocycline patients required a feeding tube during RT vs 5 placebo patients (P = 0.21). The average daily AUC during RT for the 5 MDASI-HN symptoms was 3.1 (SD = 1.0) for minocycline and 3.7 (SD = 1.7) for placebo (P = 0.16); the 0.37 effect size was less than our 0.70 target. AUC comparisons for several individual symptoms and symptom interference favored minocycline but were not statistically significant. The greatest numerical differences occurred for systemic symptoms, larger toward treatment end, and in early post-RT recovery.

CONCLUSIONS

Minocycline was feasible, well tolerated, and achieved a positive signal toward reducing patient-reported symptom severity during RT for HNC, particularly for systemic symptoms. This justifies additional study and informs future trial design.

Unresolved gustatory, olfactory and auditory adverse drug reactions to antibiotic drugs: a survey of spontaneous reporting to Eudravigilance

Objectives: Sensory adverse drug reactions (ADRs) are generally expected to be transient in nature. However, spontaneous reports describe frequently these events as long-lasting or unresolved. In this study, the authors reviewed the Eudravigilance publicly accessible database to describe the volume and expectedness of potentially unresolved outcomes for gustatory, olfactory and auditory (GOA) suspected ADRs associated with antibiotics for systemic use.Methods: 'Overall' and 'GOA' suspected ADRs were extracted from Eudravigilance to estimate the distribution of their outcomes among different antibiotic groups. Then, the authors identified the drugs contributing to at least 15% of all suspected GOA ADRs observed for the antibiotic groups, and evaluated the expectedness.Results: The frequency of persistent/permanent outcomes was higher for GOA suspected ADRs, as compared to the overall ones. Unresolved and undetermined outcomes for antibiotic-associated GOA ADRs in Eudravigilance might hide a large number of events with underestimated clinical consequences. Several persistent/permanent antibiotic-associated GOA reactions could be classified as serious and unexpected.Conclusion: Potential long-lasting or irreversible GOA reactions are often reported for all antibiotics drugs. Further studies are warranted to clarify whether this is an actual safety issue or simply it reflects a general difficulty in outcomes assessment for such reactions.

Reconsidering the Use of Minocycline in the Preliminary Treatment Regime of Rheumatoid Arthritis

Strong epidemiologic, clinical, and basic science studies have identified a number of factors that may lead to rheumatoid arthritis (RA) onset and progression, particularly involving the complex interplay between genomics, environmental risk factors, the breakdown of immune self-tolerance, and microbiome dysbiosis. A chronic state of inflammation established by infectious agents has long been suspected to set the stage for the development of RA. The purpose of this article is to review the contribution of the gut, lung, and oral microbiomes to the pathogenesis of RA and consider the importance of supplementing the preliminary treatment regime of RA patients with antibiotics, in particular, minocycline. Minocycline has been used in the treatment of RA due to its bacteriostatic, as well as immunomodulatory and anti-inflammatory properties. Ultimately, a short course of antibiotic treatment with minocycline may eliminate pathogenic organisms contributing to the development and progression of RA. 

The role of microbiome in rheumatoid arthritis treatment

Rheumatoid arthritis (RA) is an autoimmune disorder with multifactorial etiology; both genetic and environmental factors are known to be involved in pathogenesis. Treatment with disease-modifying antirheumatic drugs (DMARDs) plays an essential role in controlling disease progression and symptoms. DMARDs have immunomodulatory properties and suppress immune response by interfering in various pro-inflammatory pathways. Recent evidence has shown that the gut microbiota directly and indirectly modulates the host immune system. RA has been associated with dysbiosis of the gut microbiota. Patients with RA treated with DMARDs show partial restoration of eubiotic gut microbiome. Hence, it is essential to understand the impact of DMARDs on the microbial composition and its consequent influences on the host immune system to identify novel therapies for RA. In this review, we discuss the importance of antirheumatic-drug-induced host microbiota modulations and possible probiotics that can generate eubiosis.

Suppressive antibiotic therapy with oral tetracyclines for prosthetic joint infections: a retrospective study of 78 patients

PURPOSE

This study aimed at describing the use of oral cyclines (i.e., doxycycline and minocycline) as suppressive antibiotic therapy (SAT) in patients with periprosthetic joint infections (PJIs).

METHODS

Medical charts of all patients with surgical revisions for PJIs who were given cycline-based SAT because of a high failure of various origins were reviewed. Data regarding tolerability and effectiveness of cycline-based SAT were analysed.

RESULTS

Seventy-eight patients of mean age 64 ± 17 years received cycline-base SAT in the period from January 2006 to January 2014. PJIs involved the knee in 37 patients (47%), the hip in 35 (45%), the elbow in 4 (5%), and the shoulder in 2 (3%) and were qualified as early in 31 patients (39.7%). Staphylococcus spp. were the most common pathogens accounting for 72.1% of the total number of bacterial strains identified. All included patients had surgery which consisted in debridement and implant retention in 59 of them (75.6%). Doxycycline and minocycline were prescribed as SAT in 72 (92%) and 6 (8%) patients, respectively. Adverse events were reported in 14 patients (18%), leading to SAT discontinuation in 6 of them (8%). After a mean follow-up of 1020 ± 597 days, a total of 22 (28.2%) patients had failed including 3 cases (3.8%) with documented acquisition of tetracycline resistance in initial pathogen(s).

CONCLUSIONS

Our results suggest that oral cyclines used as SAT in patients treated for PJI have an acceptable tolerability and effectiveness and appear to be a reasonable option in this setting.

Suppressive antibiotic therapy with oral doxycycline for Staphylococcus aureus prosthetic joint infection: a retrospective study of 39 patients

The aim of this study was to describe the use of oral doxycycline as suppressive antibiotic therapy (SAT) in patients with Staphylococcus aureus periprosthetic (hip or knee) joint infections. The medical charts of all patients with surgical revisions for S. aureus hip or knee prosthetic joint infections (PJIs) who were given doxycycline-based SAT because of a high risk of failure of various origins were reviewed. Data regarding tolerability and effectiveness of doxycycline-based SAT were analysed. A total of 39 patients (mean age 66.1 ± 16.3 years) received doxycycline-base SAT in the period from January 2006 to January 2014. PJIs involved the hip in 23 patients (59.0%) and the knee in 16 (41.0%), and were qualified as early in 15 patients (38.5%). Methicillin-resistant S. aureus (MRSA) accounted for 22% of the total number of bacterial strains identified. All patients included in the study had surgery, which consisted of debridement and implant retention in 32 (82.1%). Adverse events likely attributable to SAT were reported in six patients (15.4%), leading to discontinuation of SAT in three (7.7%). A total of 29 patients (74.4%) remained event-free and 10 (25.6%) failed, including 8 (20.5%) relapses and 2 (5.1%) superinfections. Overall, 8 of the 10 failure cases were related to a doxycycline-susceptible pathogen. These results suggest that oral doxycycline used as SAT in patients treated for S. aureus hip or knee PJIs has an acceptable tolerability and effectiveness and appears to be a reasonable option in this setting.

Doxycycline protects against ROS-induced mitochondrial fragmentation and ISO-induced heart failure

In addition to their anti-bacterial action, tetracyclines also have complex biological effects, including the modification of mitochondrial protein synthesis, metabolism and gene-expression. Long-term clinical studies have been performed using tetracyclines, without significant side effects. Previous studies demonstrated that doxycycline (DOX), a major tetracyclin antibiotic, exerted a protective effect in animal models of heart failure; however, its exact molecular mechanism is still unknown. Here, we provide the first evidence that DOX reduces oxidative stress-induced mitochondrial fragmentation and depolarization in H9c2 cardiomyocytes and beneficially alters the expression of Mfn-2, OPA-1 and Drp-1 -the main regulators of mitochondrial fusion and fission-in our isoproterenol (ISO)-induced heart failure model, ultimately decreasing the severity of heart failure. In mitochondria, oxidative stress causes a shift toward fission which leads to mitochondrial fragmentation and cell death. Protecting mitochondria from oxidative stress, and the regulation of mitochondrial dynamics by drugs that shift the balance toward fusion, could be a novel therapeutic approach for heart failure. On the basis of our findings, we raise the possibility that DOX could be a novel therapeutic agent in the future treatment of heart failure.

Major involvement of bacterial components in rheumatoid arthritis and its accompanying oxidative stress, systemic inflammation and hypercoagulability

We review the evidence that infectious agents, including those that become dormant within the host, have a major role to play in much of the etiology of rheumatoid arthritis and the inflammation that is its hallmark. This occurs in particular because they can produce cross-reactive (auto-)antigens, as well as potent inflammagens such as lipopolysaccharide that can themselves catalyze further inflammagenesis, including via β-amyloid formation. A series of observables coexist in many chronic, inflammatory diseases as well as rheumatoid arthritis. They include iron dysregulation, hypercoagulability, anomalous morphologies of host erythrocytes, and microparticle formation. Iron dysregulation may be responsible for the periodic regrowth and resuscitation of the dormant bacteria, with concomitant inflammagen production. The present systems biology analysis benefits from the philosophical idea of "coherence," that reflects the principle that if a series of ostensibly unrelated findings are brought together into a self-consistent narrative, that narrative is thereby strengthened. As such, we provide a coherent and testable narrative for the major involvement of (often dormant) bacteria in rheumatoid arthritis.

Radio Frequency-Activated Nanoliposomes for Controlled Combination Drug Delivery

This work was conducted in order to design, characterize, and evaluate stable liposomes containing the hydrophobic drug raloxifene HCl (RAL) and hydrophilic doxycycline HCl (DOX), two potentially synergistic agents for treating osteoporosis and other bone lesions, in conjunction with a radio frequency-induced, hydrophobic magnetic nanoparticle-dependent triggering mechanism for drug release. Both drugs were successfully incorporated into liposomes by lipid film hydration, although combination drug loading compromised liposome stability. Liposome stability was improved by reducing the drug load and by including Pluronics® (PL) in the formulations. DOX did not appear to interact with the phospholipid membranes comprising the liposomes, and its release was maximized in the presence of radio frequency (RF) heating. In contrast, differential scanning calorimetry (DSC) and phosphorus-31 nuclear magnetic resonance ((31)P-NMR) analysis revealed that RAL developed strong interactions with the phospholipid membranes, most notably with lipid phosphate head groups, resulting in significant changes in membrane thermodynamics. Likewise, RAL release from liposomes was minimal, even in the presence of RF heating. These studies may offer useful insights into the design and optimization of multidrug containing liposomes. The effects of RAL on liposome characteristics and drug release performance underscore the importance of appropriate physical-chemical analysis in order to identify and characterize drug-lipid interactions that may profoundly affect liposome properties and performance early in the formulation development process.

Salvianolic acid A, a matrix metalloproteinase-9 inhibitor of Salvia miltiorrhiza, attenuates aortic aneurysm formation in apolipoprotein E-deficient mice

Aortic aneurysm (AA) is a life-threatening vascular disease in defect of effective pharmaceutical therapy. Matrix metalloproteinase-9 (MMP-9) is implicated in the development of chronic vascular diseases including aneurysm, but the effective MMP-9 inhibitors are far from development. To develop new candidate for AA therapy, we evaluated the efficiency of salvianolic acid A (SalA), a novel MMP-9 inhibitor, on AA progression in a mouse model and characterized the mechanism of action. SalA is a water soluble compound of the herbal drug Rhizoma Salviae miltiorrhizae (Danshen) which in China is widely used for the treatment of hypertension, coronary artery diseases and myocardial infarction. MMPs activity was evaluated by enzyme kinetic analysis in vitro and in-gel gelatin zymography in vivo. SalA showed selectivity on gelatinase (MMP-2 and MMP-9) than on collagenase (MMP-8 and MMP-13) in vitro, and specificity on MMP-9 than MMP-2 in vivo. Aortic aneurysm was induced by angiotension II (AngII) in apolipoprotein E-deficient (ApoE(-/-)) mice. Aortic structure was evaluated by hematoxylin and eosin, picrosirius red, orein stain. Macrophage infiltration was detected by immunohistochemistry in vivo and transwell in vitro. Comparing with doxycycline (Dox), a well-known MMPs inhibitor, SalA showed similar efficiency against AA progression. SalA significantly decreased aortic diameter and aneurysm severity, ameliorated integrity of vascular structure, inhibited elastin fragmentation and macrophage infiltration. Furthermore, SalA showed greater safety than Dox based on hepatotoxicity evaluation. Our results demonstrated that SalA held great potential for AA therapy.

Prospects for therapeutic tolerance in humans

PURPOSE OF REVIEW

To provide an overview of recent advances and future possibilities for therapeutic tolerance.

RECENT FINDINGS

Allograft survival despite complete immunosuppressant withdrawal has been demonstrated in selected renal-transplant recipients with haematopoietic chimerism. Early clinical trials of mesenchymal stromal cell therapy have shown promising results in several autoimmune diseases. Regulatory T cells show potential benefit in graft versus host disease, although challenges to ex-vivo expansion remain. Targeted modulation of T-cell function in vivo with monoclonal antibodies has shown beneficial effects in phase II/III trials of multiple sclerosis (alemtuzumab) and type I diabetes mellitus (teplizumab, otelixizumab). Emerging data from animal models suggest an important role for the commensal microbiome in the maintenance and disruption of immune tolerance with parallels in human studies.

SUMMARY

After years of slow progress, recent research has reduced the translational gap between animal models and clinical therapeutic tolerance. Early detection of autoimmunity, potentially at preclinical stages, offers a window of opportunity for tolerogenic therapy. Reliable biomarkers of tolerance are urgently needed to provide objective measurements of the effectiveness of tolerogenic therapies, and to allow intelligent immunosuppressant withdrawal in patients whose autoimmune disease is stable.

VIDEO ABSTRACT AVAILABLE

See the Video Supplementary Digital Content 1 (http://links.lww.com/COR/A8).

Tetracycline and Glutathione Inhibit Matrix Metalloproteinase Activity: An In Vitro Study Using Culture Supernatants of L929 and Dalton Lymphoma Cell Lines

Tetracycline and glutathione inhibited the protease activities of matrix metalloproteinase-2 and matrix metalloproteinase-9 expressed by mouse fibrosarcoma cells (L929) and Dalton lymphoma cells, respectively. The inhibitory activity of the tetracycline may be due to its ability to chelate metal ions such as calcium and zinc. Gelatin-zymography technique was used to demonstrate the inhibitory activity of both tetracycline and glutathione. The intensity of the bands corresponding to metalloproteinase activity in zymography gel was reduced in the presence of 50–100 μg/mL of tetracycline. The presence of 10–100 μg/mL of tetracycline in the medium increased the adherence of L929 cancer cells. These results clearly indicate the antimetastatic property of tetracycline. Reduced glutathione, a compound which is produced endogenously by the cells to maintain the redox status, was shown to inhibit the matrix metalloproteinase activity (in vitro). Therefore, it is assumed that decreased glutathione levels in synovial fluids or plasma might increase the activity of MMP. Reduced glutathione at 100 μg/mL inhibited the metalloproteinase activity in gelatin-zymographic gel. As both tetracycline and glutathione exhibited an inhibitory effect on matrix metalloproteinase activity, it was of great interest to check their clinical effects on various MMP associated pathological conditions such as cancer metastasis and arthritis. Here we report that tetracycline and reduced glutathione inhibited the activity of MMP2 completely and activity of MMP9 partly.

Minocycline suppresses interleukine-6, its receptor system and signaling pathways and impairs migration, invasion and adhesion capacity of ovarian cancer cells: in vitro and in vivo studies

Interleukin (IL)-6 has been shown to be a major contributing factor in growth and progression of ovarian cancer. The cytokine exerts pro-tumorigenic activity through activation of several signaling pathways in particular signal transducer and activator of transcription (STAT3) and extracellular signal-regulated kinase (ERK)1/2. Hence, targeting IL-6 is becoming increasingly attractive as a treatment option in ovarian cancer. Here, we investigated the effects of minocycline on IL-6 and its signaling pathways in ovarian cancer. In vitro, minocycline was found to significantly suppress both constitutive and IL-1β or 4-hydroxyestradiol (4-OH-E2)-stimulated IL-6 expression in human ovarian cancer cells; OVCAR-3, SKOV-3 and CAOV-3. Moreover, minocycline down-regulated two major components of IL-6 receptor system (IL-6Rα and gp130) and blocked the activation of STAT3 and ERK1/2 pathways leading to suppression of the downstream product MCL-1. In female nude mice bearing intraperitoneal OVCAR-3 tumors, acute administration (4 and 24 h) of minocycline (30 mg/kg) led to suppression of IL-6. Even single dose of minocycline was effective at significantly lowering plasma and tumor IL-6 levels. In line with this, tumoral expression of p-STAT3, p-ERK1/2 and MCL-1 were decreased in minocycline-treated mice. Evaluation of the functional implication of minocycline on metastatic activity revealed the capacity of minocycline to inhibit cellular migration, invasion and adhesion associated with down-regulation of matrix metalloproteinases (MMP)-2 and 9. Thus, the data suggest a potential role for minocycline in suppressing IL-6 expression and activity. These effects may prove to be an important attribute to the upcoming clinical trials of minocycline in ovarian cancer.

Skin hypersensitivity to sun light due to doxycycline ingestion causing hand partial-thickness burn

Drugs hypersensitivity should be remembered when placing patients on any form of medications. In this case we present skin hypersensitivity to sun light due to doxycycline ingestion causing hand partial-thickness burn.

Minocycline-associated rimmed vacuolar myopathy in a patient with rheumatoid arthritis

BACKGROUND

The autophagic vacuolar myopathies (AVM) are a group of inherited myopathies defined by the presence of autophagic vacuoles in pathological muscle specimens. AVM can be categorized into three groups: acid maltase deficiency, myopathies characterized by autophagic vacuoles with unique sarcolemmal features, and rimmed vacuolar myopathies (RVM). While the pathogeneses of these conditions are still being elucidated, some drugs (e.g., chloroquine, its analog, hydroxychloroquine, and colchicine) can also cause AVM. Minocycline is a disease-modifying anti-rheumatic drug that may be used in the treatment of rheumatoid arthritis (RA). Here, we describe the first case of minocycline-associated AVM with rimmed vacuole formation.

CASE PRESENTATION

A 75-year-old woman suffering from RA has been continuously treated with minocycline (200 mg/day) for the past 7 years. During this time, she developed a myopathy that predominantly affected her lower limbs. Histological studies of biopsied muscle revealed scattered atrophic myofibers with rimmed vacuoles that contained pigment granules. Histochemical staining revealed that the pigment comprised both iron and melanin, which is consistent with type II minocycline-induced cutaneous pigmentation. Under electron microscopy, autophagic vacuoles were consistently observed in association with numerous collections of pigment granules.

CONCLUSIONS

This is the first report of minocycline-induced pigmentation in skeletal muscle. The strong association between autophagic vacuoles and the accumulation of minocycline-induced pigments suggest that long-term minocycline treatment induced pigment accumulation, leading to elevation of autophagic activity and RVM. It might also be possible that minocycline directly activated autophagy, as the observed pigments are known to form complexes containing minocycline and/or its metabolites. As long-term minocycline treatment is expected to be used more widely in the future, we must draw attention to this adverse effect.