Dapsone as a potential treatment option for Henoch-Schönlein Purpura (HSP)

Fabrication and characterization of a Bi2O3-modified chitosan@ZIF-8 nanocomposite for enhanced drug loading-releasing efficacy

In this study, a simple novel hybrid mesoporous nanomaterial derived from a metal-organic framework (ZIF-8) and chitosan, which were coated on green bismuth oxide, has been successfully synthesized, characterized, and applied to investigate its dapsone loading-releasing capability in the aqueous media. This suggested nanocomposite showed promise for drug loading from water b using hydrogen bonds, pi-pi, and electrostatic interactions. Structural and morphological analyses were performed on the proposed green synthesized nanocomposite through scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, Brunauer-Emmett-Teller analysis, and thermogravimetric analysis. Various influencing parameters, including pH, nanocomposite dose, and contact time, were investigated to optimize the dapsone loading process. Utilizing the non-linear optimization methodology, the results show that dapsone-loading efficiency was >85 % for 50 mg.L-1 of dapsone drug. The optimum parameters for achieving maximal loading of dapsone drug were pH = 6.8, hybrid mesosphere dose = 2.6 mg.mL-1, and time = 53 min. Based on the release investigations, the dapsone-loaded nanocomposite was put into phosphate buffer saline, at pH = 7.4 and T = 37 °C, with a maximum efficiency of 93.9 after 24 h.

Causal relationships between circulating inflammatory factors and IgA vasculitis: a bidirectional Mendelian randomization study

Background

IgA vasculitis (IgAV) is an immune-associated vasculitis, yet its exact etiology remains unclear. Here, we explore the interaction between IgAV and inflammatory factors using bidirectional Mendelian randomization (MR).

Methods

We conducted a bidirectional summary-level MR analysis to delineate the causality of C-reactive protein (CRP), procalcitonin (PCT), and 41 circulating inflammatory regulators with IgAV. Data on genetic variants related to inflammation were obtained from three genome-wide association studies (GWASs) on CRP, PCT, and human cytokines, whereas data on IgAV was from large meta-analyses of GWAS among 216 569 FinnGen Biobank participants. The primary MR analysis was performed using the inverse-variance weighted (IVW) approach, and the sensitivity analyses were carried out using MR-Egger, weighted median, weighted mode, and MR-pleiotropy residual sum and outlier.

Results

This study revealed the association of CRP higher levels with increased risk of IgAV through IVW method (Estimate odds ratio [OR] = 1.41, 95% confidence interval [CI]: 1.01-1.98, P = 0.04), MR-Egger (OR = 1.87, CI: 1.15-3.02, P = 0.01), weighted median (OR = 2.00, CI: 1.21-3.30, P = 0.01) and weighted mode (OR = 1.74, CI: 1.13-2.68, P = 0.02). Furthermore, elevated IL-8 was strongly implicated with a higher risk of IgAV (IVW OR = 1.42, CI: 1.05-1.92; P = 0.02). Conversely, genetically predicted IgAV was associated with decreased levels of TNF-β (IVW estimate β = -0.093, CI: -0.178 - -0.007; P = 0.033). Additionally, no such significant statistical differences for other inflammatory factors were found.

Conclusion

Our current study using bidirectional MR analysis provides compelling evidence for a causal effect of CRP, PCT, and circulating inflammatory regulators on IgAV. These findings contribute to a better understanding of the pathogenesis of IgAV and emphasize the potential of targeting inflammatory factors for therapeutic interventions.

Dapsone for Refractory Gastrointestinal Symptoms in Children With Immunoglobulin A Vasculitis

Immunoglobulin A vasculitis (IgAV) is a systemic small-vessel vasculitis. Although corticosteroids (CS) are the primary treatment for gastrointestinal manifestations associated with IgAV, some patients develop refractory or recurrent symptoms such as vomiting and abdominal pain despite CS treatment. Dapsone, a synthetic sulfone antimicrobial, has been used to treat cutaneous purpura in IgAV, but few authors have reported its use for refractory gastrointestinal symptoms. In this retrospective observational study, we describe results in 7 children with IgAV who were treated with dapsone for abdominal pain resistant to CS. Dapsone rapidly relieved abdominal pain in all 7 patients, who then were tapered off CS without relapse. Side effects of mild methemoglobinemia and hemolysis appeared to be manageable with planned monitoring and dose adjustment; a single patient who discontinued dapsone had fatigue and hypoxia associated with methemoglobinemia. No side effects were life-threatening. Dapsone may be considered as a therapeutic option for gastrointestinal symptoms refractory to CS in children with IgAV.

Successful Treatment of IgA Vasculitis With Prolonged Cutaneous Manifestation With Colchicine in a 10-Year-Old Boy

We report a 10-year-old boy with IgA vasculitis (IgAV) with prolonged cutaneous manifestations who was successfully treated with colchicine. At the age of 9, he was diagnosed as having IgAV by typical purpura, abdominal pain, and hematochezia. Initially, his severe gastrointestinal manifestation subsided by prednisolone 60 mg/day and intravenous methylprednisolone pulse therapy. However, his gastrointestinal manifestation was glucocorticoid-dependent and refractory to factor XIII concentrate, intravenous immunoglobulin G, and mycophenolate mofetil. His abdominal pain and hematochezia responded to the combination therapy with dapsone and low dose of prednisolone 5 mg/day and did not relapse even after discontinuation of dapsone. On the other hands, the effect of dapsone on his cutaneous manifestation was dose-dependent. As well dapsone had no glucocorticoid-sparing effect. Approximately 12 months after onset, colchicine treatment was started, which resulted in remission of his chronic cutaneous manifestation. After prednisolone was tapered off, his cutaneous manifestation is currently well-controlled on colchicine 0.5 mg/day without adverse events. He had never complicated by kidney involvements. In conclusion, colchicine treatment exerts a beneficial effect in IgAV patients with prolonged cutaneous manifestation refractory to multiple drugs.

IgA Vasculitis: Etiology, Treatment, Biomarkers and Epigenetic Changes

IgA, previously called Henoch-Schönlein vasculitis, is an essential immune component that drives the host immune response to the external environment. As IgA has the unique characteristic of a flexible response to broad types of microorganisms, it sometimes causes an autoreactive response in the host human body. IgA vasculitis and related organ dysfunction are representative IgA-mediated autoimmune diseases; bacterial and viral infections often trigger IgA vasculitis. Recent drug developments and the presence of COVID-19 have revealed that these agents can also trigger IgA vasculitis. These findings provide a novel understanding of the pathogenesis of IgA vasculitis. In this review, we focus on the characteristics of IgA and symptoms of IgA vasculitis and other organ dysfunction. We also mention the therapeutic approach, biomarkers, novel triggers for IgA vasculitis, and epigenetic modifications in patients with IgA vasculitis.

Research Supporting a Pilot Study of Metronomic Dapsone during Glioblastoma Chemoirradiation

This short note presents previous research data supporting a pilot study of metronomic dapsone during the entire course of glioblastoma treatment. The reviewed data indicate that neutrophils are an integral part of human glioblastoma pathophysiology, contributing to or facilitating glioblastoma growth and treatment resistance. Neutrophils collect within glioblastoma by chemotaxis along several chemokine/cytokine gradients, prominently among which is interleukin-8. Old data from dermatology research has shown that the old and inexpensive generic drug dapsone inhibits neutrophils' chemotaxis along interleukin-8 gradients. It is on that basis that dapsone is used to treat neutrophilic dermatoses, for example, dermatitis herpetiformis, bullous pemphigoid, erlotinib-related rash, and others. The hypothesis of this paper is that dapsone will reduce glioblastomas' neutrophil accumulations by the same mechanisms by which it reduces dermal neutrophil accumulations in the neutrophilic dermatoses. Dapsone would thereby reduce neutrophils' contributions to glioblastoma growth. Dapsone is not an ideal drug, however. It generates methemoglobinemia that occasionally is symptomatic. This generation is reduced by concomitant use of the antacid drug cimetidine. Given the uniform lethality of glioblastoma as of 2020, the risks of dapsone 100 mg twice daily and cimetidine 400 mg twice daily is low enough to warrant a judicious pilot study.

Preparation and solid-state characterization of dapsone pharmaceutical cocrystals through the supramolecular synthon strategy

Based on the design concept of supramolecular synthons, “–NH2⋯Npyridine” was used to prepare cocrystals of DAP: (1 : 1) and (2 : 1) DAP-PYR, which could be transformed into each other by mechanochemistry.

4,4'-Diaminodiphenyl Sulfone (DDS) as an Inflammasome Competitor

The aim of this study is to examine the use of an inflammasome competitor as a preventative agent. Coronaviruses have zoonotic potential due to the adaptability of their S protein to bind receptors of other species, most notably demonstrated by SARS-CoV. The binding of SARS-CoV-2 to TLR (Toll-like receptor) causes the release of pro-IL-1β, which is cleaved by caspase-1, followed by the formation and activation of the inflammasome, which is a mediator of lung inflammation, fever, and fibrosis. The NLRP3 (NACHT, LRR and PYD domains-containing protein 3) inflammasome is implicated in a variety of human diseases including Alzheimer’s disease (AD), prion diseases, type 2 diabetes, and numerous infectious diseases. By examining the use of 4,4′-diaminodiphenyl sulfone (DDS) in the treatment of patients with Hansen’s disease, also diagnosed as Alzheimer’s disease, this study demonstrates the diverse mechanisms involved in the activation of inflammasomes. TLRs, due to genetic polymorphisms, can alter the immune response to a wide variety of microbial ligands, including viruses. In particular, TLR2Arg⁶⁷⁷Trp was reported to be exclusively present in Korean patients with lepromatous leprosy (LL). Previously, mutation of the intracellular domain of TLR2 has demonstrated its role in determining the susceptibility to LL, though LL was successfully treated using a combination of DDS with rifampicin and clofazimine. Of the three tested antibiotics, DDS was effective in the molecular regulation of NLRP3 inflammasome activators that are important in mild cognitive impairment (MCI), Parkinson’s disease (PD), and AD. The specific targeting of NLRP3 itself or up-/downstream factors of the NLRP3 inflammasome by DDS may be responsible for its observed preventive effects, functioning as a competitor.

Treatment of refractory IgA vasculitis with dapsone: a systematic review

IgA vasculitis, formerly known as Henoch-Schönlein purpura, is a systemic IgA-mediated vasculitis of the small vessels commonly seen in children. The natural history of IgA vasculitis is generally self-limiting; however, one-third of patients experience symptom recurrence and a refractory course. This systematic review examined the use of dapsone in refractory IgA vasculitis cases. A literature search of PubMed databases retrieved 13 articles published until June 14, 2018. The most common clinical feature was a palpable rash (100% of patients), followed by joint pain (69.2%). Treatment response within 1-2 days was observed in 6 of 26 patients (23.1%) versus within 3-7 days in 17 patients (65.4%). Relapse after treatment discontinuation was reported in 17 patients (65.4%) but not in 3 patients (11.5 %). Four of the 26 patients (15.4%) reported adverse effects of dapsone including arthralgia (7.7%), rash (7.7%), and dapsone hypersensitivity syndrome (3.8%). Our findings suggest that dapsone may affect refractory IgA vasculitis. Multicenter randomized placebo-controlled trials are necessary to determine the standard dosage of dapsone at initial or tapering of treatment in IgA vasculitis patients and evaluate whether dapsone has a significant benefit versus steroids or other medications.

Indications and efficiency of dapsone in IgA vasculitis (Henoch-Schonlein purpura): case series and a review of the literature

Immunoglobulin A (IgA) vasculitis (Henoch-Schonlein purpura (HSP)) is the most common vasculitis in children. It is characterized by purpuric rash, arthritis, gastrointestinal, and/or renal involvement. Spontaneous resolution is the typical outcome. In chronic cutaneous manifestations of IgA vasculitis, dapsone seems to show a good effectiveness. Multiple case reports and case series about dapsone in chronic IgA vasculitis are available. However, no clear evaluation of its indications, its effectiveness, or its usage guidelines (optimal dosage or duration of treatment) is available. We reviewed the published cases of IgA vasculitis treated by dapsone and compared them with 2 similar cases that we encountered. Seventeen patients (ranging from 22 months old to 16 years old) with severe or persistent clinical signs of IgA vasculitis were included. Dapsone showed good results on the resolution of cutaneous lesions but not on renal manifestations. Complications (methemoglobinemia) were observed on 1 patient. Half of the patients relapsed after treatment discontinuation. The difference between the time lapse before initiation and the duration of the treatment was not significant.Conclusion: We suggest that dapsone can have a positive effect in chronic IgA vasculitis when cutaneous manifestations last more than 6 weeks at the dosage of 1-2 mg/kg once per day during 1 week. What is Known: • IgA vasculitis or Henoch-Schonlein purpura is the most common vasculitis in children and affects mostly small vessels of the skin, kidney, and gastrointestinal tract. It resolves spontaneously in most of the cases. Exceptionally, cutaneous lesions can last several weeks. • Dapsone is a bacteriostatic antibacterial sulfonamide drug found to be effective in the treatment of some inflammatory dermatological diseases like IgA vasculitis. What is New: • Dapsone is effective against chronic purpuric lesion (> 6 weeks) at the minimal dose of 1 mg/kg/day. • Relapse occurs frequently after discontinuation but responds after a second course of treatment. A longer duration of treatment or a delay in treatment by dapsone does not seem to influence the relapse rate.

Preparation of polyacrylamide/polylactic acid co-assembled core/shell nanofibers as designed beads for dapsone in vitro efficient delivery

The main aim of this study is to synthesize and prepare polyacrylamide (PAM)/polylactic acid (PLA) co-assembled core/shell nanofibers in order to investigate an effective dapsone-loaded capability and dapsone-release in the aqueous medium. Dapsone (4,4-diamino-diphenyl sulfone) has high permeability and low solubility in water. In vitro release testing indicates that maximum incorporation of the dapsone nanoemulsions into core/shell nanofibrous structures were 77.71 after 400 min. Products were characterized with X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FT-IR), Thermo-Gravimetric Analysis (TGA), Dynamic light scattering (DLS) analysis, Contact Angle Measurement (CAM) and nitrogen adsorption [i.e. Brunauer-Emmett-Teller (BET) Surface Area Analysis] techniques. The porosimetric measurements of the nanofibers structures showed that high porosity diameter, adsorption cross-section area, pore volumes and dead volume were obtained as 0.162 nm², 0.1005 cm³g^-1 and 15.693 cm³, respectively. TGA curve of the core/shell nanofibrous structures shows thermal stability between 240 °C and 260 °C.

Development and Characterization of Dapsone Cocrystal Prepared by Scalable Production Methods

In this study, the formation of caffeine/dapsone (CAF/DAP) cocrystals by scalable production methods, such as liquid-assisted grinding (LAG) and spray drying, was investigated in the context of the potential use of processed cocrystal powder for pulmonary delivery. A CAF/DAP cocrystal (1:1 M ratio) was successfully prepared by slow evaporation from both acetone and ethyl acetate. Acetone, ethyl acetate, and ethanol were all successfully used to prepare cocrystals by LAG and spray drying. The powders obtained were characterized by X-ray diffractometry (XRD), differential scanning calorimetry (DSC), thermogravimetry (TGA), and Fourier transform infrared spectroscopy (FTIR). Laser diffraction analysis indicated a median particle size (D₅₀) for spray-dried powders prepared from acetone, ethanol, and ethyl acetate of 5.4 ± 0.7, 5.2 ± 0.1, and 5.1 ± 0.0 μm respectively, which are appropriate sizes for pulmonary delivery by means of a dry powder inhaler. The solubility of the CAF/DAP cocrystal in phosphate buffer pH 7.4, prepared by spray drying using acetone, was 506.5 ± 31.5 μg/mL, while pure crystalline DAP had a measured solubility of 217.1 ± 7.8 μg/mL. In vitro cytotoxicity studies using Calu-3 cells indicated that the cocrystals were not toxic at concentrations of 0.1 and of 1 mM of DAP, while an in vitro permeability study suggested caffeine may contribute to the permeation of DAP by hindering the efflux effect. The results obtained indicate that the CAF/DAP cocrystal, particularly when prepared by the spray drying method, represents a possible suitable approach for inhalation formulations with applications in pulmonary pathologies.