Effect of mast cell stabilization on angiogenesis in primary and secondary experimental Trichinella spiralis infection.

BACKGROUND: Mast cells are known to affect the primary and secondary immune responses against parasites, and this effect is partially mediated through the release of pro-angiogenic mediators. The aim of this study was to explore the effect of the mast cell stabilizer (MCS), ketotifen, with and without albendazole, an anti-parasitic prescription medicine, on the inflammatory response against Trichinella spiralis, with the overall aim to investigate its effect on angiogenesis accompanying nurse cell formation. METHODS: The effect of ketotifen and albendazole was explored in eight groups of female BALB/c mice. Four groups were sensitized with a small dose of T. spiralis larvae. The drug regimen was then applied to both sensitized (challenged) and non-sensitized mice. The parasite load was assessed by histopathological examination of the small intestine and muscle tissue, and angiogenesis was assessed by immunohistochemistry to determine the expression of vascular endothelial growth factor (VEGF). RESULTS: Sensitized mice showed a significantly lower parasite load and a more pronounced inflammatory response than mice receiving a single infective dose of T. spiralis larvae. All treated groups showed a significant reduction in parasite count compared to the control groups (groups IAa and IBa), reaching approximately an 98.8% reduction in adult parasite count in the sensitized group treated with albendazole (groups IIAb and IIBb). MCS significantly decreased the parasite count during both the intestinal or muscular phases, reduced tissue inflammation, and decreased local VEGF expression, both in the non-sensitized and sensitized groups. CONCLUSION: Sensitization with a low dose of T. spiralis larvae was found to confer a partial protective immunity against re-infection and to positively affect the study outcomes, thus underlining the importance of vaccination, but after extensive studies. The anti-angiogenic effect of MCS protects against larval encystation during the muscle phase. The anti-angiogenic potential of albendazole suggests that the action of this anti-helminthic during trichinellosis is not confined to structural damage to the parasite cuticle but includes an effect on host immunopathological response.

Functional observation after morphine withdrawal: effects of SJP-005.

RATIONALE AND OBJECTIVE: SJP-005 (ketotifen and ibuprofen) is being developed as a potential new treatment for opioid withdrawal. Three studies were conducted to evaluate the early phase (acute, day 1) and late phase (days 2-12) effects of SJP-005 on discontinuation-induced morphine withdrawal. METHODS: Sprague-Dawley rats received subcutaneous morphine twice daily for 18 days and ceased on day 19. Twice daily, oral dosages of placebo or SJP-005 (1 mg/kg ketotifen and 15 mg/kg ibuprofen) were administered starting 4 days before (study 1), 2 days before (study 2), or immediately after (study 3) morphine cessation. Functional observations were made up to 12 h after treatment cessation on day 19 (early phase), and immediately after treatment on days 20-30 (late phase). Treatment effects (mean overall score, and individual symptoms) were compared with placebo using ANOVA, and Tukey's tests in case of multiple comparisons. RESULTS: Across the studies, the number of withdrawal signs on day 19 (early phase) and days 20-30 (late phase) was lower with SJP-005 compared with placebo. The effects of SJP-005 when treatment was initiated 2 days before morphine cessation by discontinuation were most pronounced and statistically significant in the late phase (F(1,18) = 14.10, p = 0.001). In particular, a significant reduction was observed in hypersensitivity to touch (F(1,18) = 13.65, p = 0.002). A 50% reduction in withdrawal symptoms was observed 9.0 days after placebo versus 4.5 days after SJP-005. After 9.0 days, all withdrawal symptoms were absent in the SJP-005 group, while symptoms in the placebo group were still evident on day 18. CONCLUSION: Compared to placebo, SJP-005 significantly reduced the incidence and duration of discontinuation-induced morphine withdrawal symptoms when treatment was initiated 2 days before morphine cessation.

Reduction of arthrofibrosis utilizing a collagen membrane drug-eluting scaffold with celecoxib and subcutaneous injections with ketotifen.

The dense formation of abnormal scar tissue after total knee arthroplasty results in arthrofibrosis, an unfortunate sequela of inflammation. The purpose of this study was to use a validated rabbit model to assess the effects on surgically-induced knee joint contractures of two combined pharmacological interventions: celecoxib (CXB) loaded on an implanted collagen membrane, and subcutaneously (SQ) injected ketotifen. Thirty rabbits were randomly divided into five groups. The first group received no intervention after the index surgery. The remaining four groups underwent intra-articular implantation of collagen membranes loaded with or without CXB at the time of the index surgery; two of which were also treated with SQ ketotifen. Biomechanical joint contracture data were collected at 8, 10, 16, and 24 weeks. At the time of necropsy (24 weeks), posterior capsule tissue was collected for messenger RNA and histopathologic analyses. At 24 weeks, there was a statistically significant increase in passive extension among rabbits in all groups treated with CXB and/or ketotifen compared to those in the contracture control group. There was a statistically significant decrease in COL3A1, COL6A1, and ACTA2 gene expression in the treatment groups compared to the contracture control group (P < .001). Histopathologic data also demonstrated a trend towards decreased fibrous tissue density in the CXB membrane group compared to the vehicle membrane group. The present data suggest that intra-articular placement of a treated collagen membrane blunts the severity of contracture development in a rabbit model of arthrofibrosis, and that ketotifen and CXB may independently contribute to the prevention of arthrofibrosis. Statement of clinical significance: Current literature has demonstrated that arthrofibrosis may affect up to 5% of primary total knee arthroplasty patients. For that reason, novel pharmacologic prophylaxis and treatment modalities are critical to mitigating reoperations and revisions while improving the quality of life for patients with this debilitating condition.

PrEvention of posttraumatic contractuRes with Ketotifen 2 (PERK 2) - protocol for a multicenter randomized clinical trial.

BACKGROUND: Injuries and resulting stiffness around joints, especially the elbow, have huge psychological effects by reducing quality of life through interference with normal daily activities such as feeding, dressing, grooming, and reaching for objects. Over the last several years and through numerous research results, the myofibroblast-mast cell-neuropeptide axis of fibrosis had been implicated in post-traumatic joint contractures. Pre-clinical models and a pilot randomized clinical trial (RCT) demonstrated the feasibility and safety of using Ketotifen Fumarate (KF), a mast cell stabilizer to prevent elbow joint contractures. This study aims to evaluate the efficacy of KF in reducing joint contracture severity in adult participants with operately treated elbow fractures and/or dislocations. METHODS/DESIGN: A Phase III randomized, controlled, double-blinded multicentre trial with 3 parallel groups (KF 2 mg or 5 mg or lactose placebo twice daily orally for 6 weeks). The study population consist of adults who are at least 18 years old and within 7 days of injury. The types of injuries are distal humerus (AO/OTA type 13) and/or proximal ulna and/or proximal radius fractures (AO/OTA type 2 U1 and/or 2R1) and/or elbow dislocations (open fractures with or without nerve injury may be included). A stratified randomization scheme by hospital site will be used to assign eligible participants to the groups in a 1:1:1 ratio. The primary outcome is change in elbow flexion-extension range of motion (ROM) arc from baseline to 12 weeks post-randomization. The secondary outcomes are changes in ROM from baseline to 6, 24 & 52 weeks, PROMs at 2, 6, 12, 24 & 52 weeks and impact of KF on safety including serious adverse events and fracture healing. Descriptive analysis for all outcomes will be reported and ANCOVA be used to evaluate the efficacy KF over lactose placebo with respect to the improvement in ROM. DISCUSSION: The results of this study will provide evidence for the use of KF in reducing post-traumatic joint contractures and improving quality of life after joint injuries. TRIAL REGISTRATION: This study was prospectively registered (July 10, 2018) with ClinicalTrials.gov reference: NCT03582176.

Calming Down Mast Cells with Ketotifen: A Potential Strategy for Multiple Sclerosis Therapy?

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS) characterized by extensive inflammation, demyelination, axonal loss and gliosis. Evidence indicates that mast cells contribute to immunopathogenesis of both MS and experimental autoimmune encephalomyelitis (EAE), which is the most employed animal model to study this disease. Considering the inflammatory potential of mast cells, their presence at the CNS and their stabilization by certain drugs, we investigated the effect of ketotifen fumarate (Ket) on EAE development. EAE was induced in C57BL/6 mice by immunization with MOG35-55 and the animals were injected daily with Ket from the seventh to the 17th day after disease induction. This early intervention with Ket significantly reduced disease prevalence and severity. The protective effect was concomitant with less NLRP3 inflammasome activation, rebalanced oxidative stress and also reduced T cell infiltration at the CNS. Even though Ket administration did not alter mast cell percentage at the CNS, it decreased the local CPA3 and CMA1 mRNA expression that are enzymes typically produced by these cells. Evaluation of the CNS-barrier permeability indicated that Ket clearly restored the permeability levels of this barrier. Ket also triggered an evident lymphadenomegaly due to accumulation of T cells that produced higher levels of encephalitogenic cytokines in response to in vitro stimulation with MOG. Altogether these findings reinforce the concept that mast cells are particularly relevant in MS immunopathogenesis and that Ket, a known stabilizer of their activity, has the potential to be used in MS control.

Development of a Carrier Free Dry Powder Inhalation Formulation of Ketotifen for Pulmonary Drug Delivery.

BACKGROUND: Pulmonary drug delivery route is gaining much attention because it enables to target the active ingredients directly to lung both for local and systemic treatments, which maximize the therapeutic effect and minimize unwanted systemic toxicity. Dry powder inhaler (DPI) systems for asthma therapy have shown several merits to the other pulmonary delivery systems such as nebulizers and metered dose inhalers. PURPOSE: The present study aims to develop and optimize a DPI formulation for Ketotifen fumarate through spray drying technique. METHODS: Particles size and morphology, crystallinity, and drug-excipient interaction of fabricated DPI formulations were evaluated by scanning electron microscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Fourier Transform Infrared Spectroscopy methods, respectively. The aerosolization indexes and aerodynamic properties of dry powders were determined by next generation impactor. The powder flowability was assessed by measuring the Hausner ratio and compressibility index. RESULTS: Among solvent systems, ethanol-water mixture produced the most desirable powder property for inhalation after spray drying. Although co-spray dried formulations with ammonium bicarbonate resulted in the porous structure, it was not beneficial for DPI formulations due to the interaction with Ketotifen. DSC and XRD experiments proved the amorphous structure of prepared powders, which were stable for 12 months. CONCLUSION: The results of this study demonstrate the potential of Ketotifen DPI formulation and pave a way to use it easily in an industrial scale.

Pharmacokinetic/pulmokinetic analysis of optimized lung targeted spray dried ketotifen-dextran core shell nanocomplexes-in-microparticles.

A passive lung targeted system for controlled lung delivery of ketotifen (KT) was developed based on the green complexation of dextran sulphate (DS) and KT. Achieving deep lung deposition of high drug fraction, while evading lung defense mechanisms were set as goals. Optimized uniform negatively charged nanocomplexes (NC), <80 nm, were obtained at KT/DS weight ratio of 1:0.66 to 1:0.5 and 1% surfactant concentration with 90% drug complexation efficiency. The interaction between KT and DS and matrix formation were evidenced by Fourier-transform infrared (FT-IR) spectra and differential scanning calorimetry (DSC) studies. A respirable particle percent reaching 67.41 ±â€¯2.6% was obtained following co-spray drying NC containing poloxamer with leucine. A higher lung/plasma partitioning was obtained following pulmonary administration of selected nanocomplexes in microparticles (NCEMP) to rats compared to oral and intravenous (iv) routes. A new core shell nanocomplex formed of DS and KT as main substrates exhibited a potential for lung targeting of the anti-asthmatic drug.

Management of Ocular Allergy Itch With an Antihistamine-Releasing Contact Lens.

PURPOSE: A contact lens (CL)-based drug delivery system for therapeutic delivery of the antihistamine ketotifen was tested in 2 parallel, conjunctival allergen challenge-based trials. METHODS: Both trials employed the same multicenter, randomized, placebo-controlled protocol. Test lenses were etafilcon A with 0.019 mg ketotifen; control lenses were etafilcon A with no added drug. Subjects were randomized into 3 treatment groups. Group 1 received test lens in one eye and control lens in the contralateral eye; the eye chosen to receive test lens was randomly selected in a 1:1 ratio. Group 2 received test lenses bilaterally, and group 3 received control lenses bilaterally. Allergen challenges were conducted on 2 separate visits: following lens insertion, the subjects were challenged at 15 minutes (to test onset) and 12 hours (to test duration). The primary endpoint was ocular itching measured using a 0 to 4 scale with half-unit steps. Secondary endpoints included ciliary, conjunctival, and episcleral hyperemia. RESULTS: The mean itching scores were lower for eyes wearing the test lens as compared to those that received control lenses, indicating that the test lens effectively reduced allergic responses. Mean differences in itching were statistically and clinically significant (mean score difference ≥ 1) at both onset and duration for both trials. CONCLUSIONS: This large-scale assessment (n = 244) is the first demonstration of efficacy for CL delivery of a therapeutic for ocular allergy. Results are comparable to direct topical drug delivery and suggest that the lens/ketotifen combination can provide a means of simultaneous vision correction and treatment for CL wearers with ocular allergies.

Efficacy and Tolerability of Ketotifen in the Treatment Of Seasonal Allergic Conjunctivitis: Comparison between Ketotifen 0.025% and 0.05% Eye Drops.

Purpose: To study the tolerability and efficacy of two formulations of topical ketotifen ophthalmic solutions for the treatment of seasonal allergic conjunctivitis (SAC).Methods: 81 active SAC patients were treated with either ketotifen 0.025% or 0.05% eye drops for 3 weeks. Allergic signs and symptoms were evaluated at baseline (V0), after 7 (V1) and 21 days (V2). Drugs tolerability and ratings of global efficacy were recorded.Results: Both concentrations of ketotifen were highly effective. The total signs and symptoms scores (TSSS) were significantly better reduced by ketotifen 0.025% compared to 0.05% at both V1 and V2 (p < 0.001). Ketotifen 0.025% was better tolerated than 0.05% at the first instillation and at days 2, 4, and 6 (p < 0.0001), and had a better responder rate (p < 0.001) according to the patient's and investigator's assessments.Conclusions: Ketotifen 0.025% was more effective and better tolerated than 0.05% in SAC.

A Prospective Study on the Prevalence, Extent of Disease and Outcome of Eosinophilic Gastroenteritis in Patients Presenting with Lower Abdominal Symptoms.

BACKGROUND/AIMS: The epidemiology of eosinophilic gastroenteritis remains unclear. We aim to determine the prevalence of eosinophilic gastroenteritis in patients with lower abdominal symptoms. METHODS: In a prospective study, colonoscopy was performed on 2,469 consecutive patients. Biopsies were taken from the terminal ileum and ascending, transverse, descending and sigmoid colon in all patients. RESULTS: Sixty-four of the 2,469 patients (2.6%) had eosinophilic gastroenteritis. Only five of the 64 patients (7.8%) with eosinophilic gastroenteritis had endoscopic mucosal abnormalities during colonoscopy. Six of these 64 patients (9.4%) had severe disease at presentation, and seven of these 64 patients (10.9%) required systemic steroid treatment. An elevated absolute peripheral eosinophil count was independently associated with severe disease at presentation (4/6 [66.7%] vs 3/58 [5.2%], p=0.005; odds ratio [OR], 25.320; 95% confidence interval [CI], 2.628 to 243.910), and severe disease at the time of presentation was independently associated with the use of systemic steroid treatment (6/7 [85.7%] vs 0/57 [0%], p=0.008; OR, 18.021; 95% CI, 2.163 to 150.152). CONCLUSIONS: The prevalence of eosinophilic gastroenteritis is common, and patients usually present normal-appearing mucosa on colonoscopy. Those with severe disease at presentation usually have a raised absolute peripheral eosinophil count and should be commenced on systemic steroids as an initial therapy.

Transcriptional Profiling Confirms the Therapeutic Effects of Mast Cell Stabilization in a Dengue Disease Model.

There are no approved therapeutics for the treatment of dengue disease despite the global prevalence of dengue virus (DENV) and its mosquito vectors. DENV infections can lead to vascular complications, hemorrhage, and shock due to the ability of DENV to infect a variety of immune and nonimmune cell populations. Increasingly, studies have implicated the host response as a major contributor to severe disease. Inflammatory products of various cell types, including responding T cells, mast cells (MCs), and infected monocytes, can contribute to immune pathology. In this study, we show that the host response to DENV infection in immunocompetent mice recapitulates transcriptional changes that have been described in human studies. We found that DENV infection strongly induced metabolic dysregulation, complement signaling, and inflammation. DENV also affected the immune cell content of the spleen and liver, enhancing NK, NKT, and CD8+ T cell activation. The MC-stabilizing drug ketotifen reversed many of these responses without suppressing memory T cell formation and induced additional changes in the transcriptome and immune cell composition of the spleen, consistent with reduced inflammation. This study provides a global transcriptional map of immune activation in DENV target organs of an immunocompetent host and supports the further development of targeted immunomodulatory strategies to treat DENV disease.IMPORTANCE Dengue virus (DENV), which causes febrile illness, is transmitted by mosquito vectors throughout tropical and subtropical regions of the world. Symptoms of DENV infection involve damage to blood vessels and, in rare cases, hemorrhage and shock. Currently, there are no targeted therapies to treat DENV infection, but it is thought that drugs that target the host immune response may be effective in limiting symptoms that result from excessive inflammation. In this study, we measured the host transcriptional response to infection in multiple DENV target organs using a mouse model of disease. We found that DENV infection induced metabolic dysregulation and inflammatory responses and affected the immune cell content of the spleen and liver. The use of the mast cell stabilization drug ketotifen reversed many of these responses and induced additional changes in the transcriptome and immune cell repertoire that contribute to decreased dengue disease.

Effect of Intervention in Mast Cell Function Before Reperfusion on Renal Ischemia-Reperfusion Injury in Rats.

BACKGROUND/AIMS: Mast cells are sparsely distributed in the kidneys under normal conditions; however, the number of mast cells increases dramatically during renal ischemia/reperfusion injury (RI/RI). When mast cells are stimulated, numerous mediators are released, and under pathological conditions, they produce a wide range of biological effects. The aim of this study was to investigate the effect of intervention in mast cell function before reperfusion on RI/RI. METHODS: Sprague-Dawley (SD) rats (n=50) were randomized into five groups: sham group, ischemia/reperfusion (I/R) group, cromolyn sodium treatment group (CS+I/R group), ketotifen treatment group (K+I/Rgroup), and compound 48/80 treatment group (C+I/R group). I/R injury was induced by bilateral renal artery and vein occlusion for 45 min followed by 24 h of reperfusion. The agents were intravenously administered 5 min before reperfusion through the tail vein. The serum levels of blood urea nitrogen(BUN), serum creatinine (Scr) and histamine and the kidney levels of malondialdehyde (MDA), superoxide dismutase (SOD), tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) were assessed. The expression of intracellular adhesion molecule-1 (ICAM-1) in renal tissue was also measured. RESULTS: I/R injury resulted in severe renal injury, as demonstrated by a large increase in injury scores; serum levels of BUN, Scr and histamine; and kidney levels of MDA, TNF-α, and IL-6; this was accompanied by reduced SOD activity and upregulated ICAM-1 expression. Treatment with cromolyn sodium or ketotifen markedly alleviated I/R-mediated kidney injury, whereas compound 48/80 further aggravated kidney injury. CONCLUSION: Intervention in mast cell activity prior to reperfusionhas a strong effect on RI/RI.

Mast Cell Stabilizer Ketotifen Inhibits Gouty Inflammation in Rats.

Gout, an extremely painful arthritis with relapsing inflammatory attacks, is a common inflammatory joint disease in adults. We examined the therapeutic effect of ketotifen, a mast cell stabilizer, on monosodium urate (MSU) crystal-induced acute inflammation. Eight-week-old male Wistar rats were injected with MSU crystals (5 mg per rat) into air pouch. Ketotifen (0, 0.1, 03, and 1 mg/kg) was given 1 hour before MSU crystal injection. Lavage histamine, leukocyte counts, mast cell counts, nitric oxide, and proinflammatory mediator levels were assessed 12 hours after MSU injection. Ketotifen significantly inhibited MSU-induced mast cell activation and histamine concentration in air pouch lavage. Ketotifen dose-dependently inhibited MSU-initiated leukocyte infiltration into the air pouch. Furthermore, ketotifen significantly decreased proinflammatory mediators, including nitric oxide, interleukin-1ß, and interleukin-6, production in MSU-treated rats. Ketotifen may attenuate MSU-induced acute inflammation by inhibiting mast cell activation and leukocyte infiltration in rats. Furthermore, ketotifen has the potential to be a new approach in managing patients with gouty inflammation in the future.

A novel in situ gel base of deacetylase gellan gum for sustained ophthalmic drug delivery of ketotifen: in vitro and in vivo evaluation.

In this study, an ion-activated ketotifen ophthalmic delivery system was developed by using a natural polysaccharide, deacetylase gellan gum. Its rheological characteristics, stability, in vitro gelation, release in vitro, and pharmacodynamic activity in vivo were investigated. The formulation had an optimum viscosity that will allow easy drop as a liquid, which then underwent a rapid sol-gel transition due to ionic interaction. There were negligible alterations in the initial values of viscosity of the formulations over a storage period of 180 days. The in vitro release profiles indicated that the release of ketotifen from in situ gels exhibited a sustained feature. Scintigraphic studies indicated that deacetylase gellan gum could increase the residence time of the formulation. At the same dose, in situ gels demonstrated a typical sustained and prolonged drug-effects behavior compared with the common drops.

Characterization and Validation of a Canine Pruritic Model.

Preclinical Research The mechanisms mediating canine pruritus are poorly understood with few models due to limited methods for inducing pruritus in dogs. Chloroquine (CQ) is a widely used antimalarial drug that causes pruritus in humans and mice. We have developed a canine model of pruritus where CQ reliably induced pruritus in all dogs tested following intravenous administration. This model is presently being used to test antipruritic activity of drug candidate molecules. This publication has been validated in a blinded cross-over study in eight beagle dogs using the reference standards, oclacitinib and prednisolone, and has been used to test a new compound, norketotifen. All compounds reduced CQ-induced pruritus in the dog. The sensitivity of the model was demonstrated using norketotifen, which at three dose levels, dose-dependently, inhibited scratching events compared with placebo.

Ketotifen suppression of NF1 neurofibroma growth over 30 years.

A patient with NF1 was treated with oral ketotifen for 30 years since infancy. Review of the patient's course and treatment details establishes a basis for reconsideration of several fundamental precepts about NF1 pathogenesis. The data suggest a distinctive benefit to treating an NF1 patient with an inhibitor of mast cell degranulation before cutaneous neurofibromas are clinically apparent: the neurofibromas appear to be arrested at a very early stage of development. The patient's skin was especially remarkable for both the paucity of cutaneous neurofibromas and the distinctive monotonous uniformity of those present, which were small and flat or barely sessile. While the data do not, of themselves, prove that ketotifen treatment commencing in childhood preempts neurofibroma maturation, in the context of earlier publications, they certainly warrant further investigation.

Comparing the effects of ketotifen fumarate eye drops and ketotifen oral pills on symptom severity and quality of life in patients with allergic rhinitis: a double-blind randomized clinical trial.

BACKGROUND: Allergic rhinitis is a chronic inflammatory disease of nasal mucosa. Previous studies have shown the therapeutic effects of ketotifen eye drops on allergic conjunctivitis and rhinitis patients. This study was designed to compare the effects of ketotifen drops and oral ketotifen pills on symptoms and quality of life in allergic rhinitis patients. METHODS: In this double-blind randomized clinical trial, patients with mild allergic rhinitis who were referred to the allergy clinic of Baqiyatallah Hospital from March to April 2014 were randomly allocated to 2 groups; the first group received ketotifen drops (1 drop every 12 hours) with placebo pills (2 pills daily), and the second group received placebo eye drops with ketotifen pills for 4 weeks. Symptoms (sneezing, runny nose, itching, and nasal obstruction) severity were examined and Rhinitis Quality of Life Questionnaire (RQLQ) scores were evaluated in the second and fourth weeks. RESULTS: A total of 140 patients were evaluated in 2 groups. The mean age was 30.33 years. There were no significant differences in demographic data between the groups (p > 0.05). Both groups showed a significant improvement in rhinorrhea, nasal congestion, nasal itching, coughing, sneezing, RQLQ, and nasal smear eosinophil percent compared to baseline amounts (p < 0.05). Improvements were significantly more in the drops group (p < 0.05). CONCLUSION: Because of the absence of systemic complications in ketotifen eye drops in patients with allergic rhinitis and their easy availability in Iran, using this medication instead of systemic therapies is suggested. Nevertheless, more studies are required to evaluate the long-term effects of using this drug and the recurrence rate of symptoms.

In vitro effects of preserved and unpreserved anti-allergic drugs on human corneal epithelial cells.

PURPOSE: Treatment with topical eye drops for long-standing ocular diseases like allergy can induce detrimental side effects. The purpose of this study was to investigate in vitro cytotoxicity of commercially preserved and unpreserved anti-allergic eye drops on the viability and barrier function of monolayer and stratified human corneal-limbal epithelial cells. METHODS: Cells were treated with unpreserved ketotifen solution, benzalkonium chloride (BAC)-containing anti-allergic drugs (ketotifen, olopatadine, levocabastine) as well as BAC alone. 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was used to determine cell viability. Effects of compounds on barrier function were analyzed measuring transepithelial electrical resistance (TEER) to determine paracellular permeability and rose bengal assays to evaluate transcellular barrier formation. RESULTS: The BAC-preserved anti-allergic formulations and BAC alone significantly reduced cell viability, monolayer cultures being more sensitive to damage by these solutions. Unpreserved ketotifen induced the least diminution in cell viability. The extent of decrease of cell viability was clearly dependent of BAC presence, but it was also affected by the different types of drugs when the concentration of BAC was low and the short time of exposure. Treatment with BAC-containing anti-allergic drugs and BAC alone resulted in increased paracellular permeability and loss of transcellular barrier function as indicated by TEER measurement and rose bengal assays. CONCLUSIONS: The presence of the preservative BAC in anti-allergic eye drop formulations contributes importantly to the cytotoxic effects induced by these compounds. Stratified cell cultures seem to be a more relevant model for toxicity evaluation induced on the ocular surface epithelia than monolayer cultures.

[Mast cell activation disease: a concise practical guide for diagnostic workup and therapeutic options]. / Systemische Mastzellaktivierungserkrankung: Ein praxisorientierter Leitfaden zu Diagnostik und Therapie.

In the present paper clinical phenotypes, pathogenetic relationships, and diagnostic algorithms as well as therapeutic concepts of/for systemic mast cell activation disease are reviewed. The reader should be able to recognize and diagnose a systemic mast cell activation disease, as well as to counsel a personalized drug therapy. In the case of chronic multisystem polymorbidity systemic mast cell activation disease should be considered as a differential diagnosis at an early stage. In most cases, specific, little invasive investigations allow diagnosing the disease and, hence, an appropriate therapy can be initiated.