Phenotypic and Immunological Characterization of Patients with Activated PI3Kδ Syndrome 1 Presenting with Autoimmunity.

PURPOSE: Autoimmunity is a significant feature of APDS1 patients. We aimed to explore the pathogenic immune phenotype and possible mechanisms of autoimmunity in APDS1 patients. METHODS: The clinical records and laboratory data of 42 APDS1 patients were reviewed. Immunophenotypes were evaluated by multiparametric flow cytometry. Autoantibodies were detected via antigen microarray analysis. RESULTS: A total of 42 children with PIK3CD gene mutations were enrolled. Immunological tests revealed increased proportions of effector memory cells (86%) and central memory cells (59%) among CD4+ T cells; increased proportions of effector memory cells (83%) and terminally differentiated effector memory T cells (38%) among CD8+ T cells. Fewer CD3+ T cells and B cells and higher IgG levels were reported in patients with autoimmunity. The proportion of Tregs was decreased, and the proportions of Th9, Tfh, and Tfr cells were increased in APDS1 patients. Among APDS1 patients, higher proportion of Th2 and Tfr cells were found in those with autoimmunity. The proportions of CD11c+ B and CD21lo B cells in patients with autoimmunity were significantly increased. Antigen microarray analysis revealed a wide range of IgG/IgM autoantibodies in patients with APDS1. In patients with autoimmunity, the proportion of Tfr might be positively correlated with autoantibodies. CONCLUSIONS: The pathogenic immune phenotype of APDS1 patients included (1) deceased CD3+ T-cell and B-cell counts and increased IgG levels in patients with autoimmunity, (2) an imbalanced T helper cell subset, (3) increased proportions of autoreactive B cells, and (4) distinct autoantibody reactivities in patients with autoimmunity.

Clinical and Genetic Characteristics of BCG Disease in Chinese Children: a Retrospective Study.

PURPOSE: Summarize the characteristics of a large cohort of BCG disease and compare differences in clinical characteristics and outcomes among different genotypes and between primary immunodeficiency disease (PID) and patients without identified genetic etiology. METHODS: We collected information on patients with BCG disease in our center from January 2015 to December 2020 and divided them into four groups: chronic granulomatous disease (CGD), Mendelian susceptibility to mycobacterial disease (MSMD), severe combined immunodeficiency disease (SCID), and gene negative group. RESULTS: A total of 134 patients were reviewed, and most of them had PID. A total of 111 (82.8%) patients had 18 different types of pathogenic gene mutations, most of whom (91.0%) were classified with CGD, MSMD, and SCID. CYBB was the most common gene mutation (52/111). BCG disease behaves differently in individuals with different PIDs. Significant differences in sex (P < 0.001), age at diagnosis (P = 0.013), frequency of recurrent fever (P = 0.007), and vaccination-homolateral axillary lymph node enlargement (P = 0.039) and infection severity (P = 0.006) were noted among the four groups. The CGD group had the highest rate of males and the oldest age at diagnosis. The MSMD group had the highest probability of disseminated infection (48.3%). The course of anti-tuberculosis treatment and the survival time between patients with PID and without identified genetic etiology were similar. CONCLUSION: Greater than 80% of BCG patients have PID; accordingly, gene sequencing should be performed in patients with BCG disease for early diagnosis. BCG disease behaves differently in patients with different types of PID. Patients without identified genetic etiology had similar outcomes to PID patients, which hints that they may have pathogenic gene mutations that need to be discovered.

Variant Type X91+ Chronic Granulomatous Disease: Clinical and Molecular Characterization in a Chinese Cohort.

PURPOSE: We aimed to report the clinical and immunological characteristics of variant type X91+ chronic granulomatous disease (CGD) in a Chinese cohort. METHODS: The clinical manifestations and immunological phenotypes of patients with X91+ CGD were collected. A dihydrorhodamine (DHR) analysis was performed to evaluate neutrophil function. Gp91phox protein expression was determined using extracellular staining with the monoclonal antibody (mAb) 7D5 and flow cytometry. RESULTS: Patients with X91+ CGD accounted for 8% (7/85) of all patients with CGD. The median age of onset in the seven patients with X91+ CGD was 4 months. Six patients received the BCG vaccine, and 50% (3/6) had probable BCG infections. Mycobacterium tuberculosis infection was prominent. The most common sites of infection were the lung (6/7), lymph nodes (5/7), and soft tissue (3/7). Two patients experienced recurrent oral ulcers. The stimulation index (SI) of the patients with X91+ CGD ranged widely from 1.9 to 67.3. The difference in the SI among the three groups of patients (X91+ CGD, X91- CGD, and X910 CGD) was statistically significant (P = 0.0071). The three groups showed no significant differences in onset age, diagnosis age, or severe infection frequency. CYBB mutations associated with X91+ CGD were commonly located in the second transmembrane or intracellular regions. Three novel X91+ CGD-related mutations (c.1462-2 A > T, c.1243C > T, and c.925G > A) were identified. CONCLUSIONS: Variant type X91+ CGD may result in varied clinical manifestations. Moreover, the laboratory findings might indicate a moderate neutrophil SI. We should deepen our understanding of variant X91+ CGD to prevent missed diagnoses.

Efficacy of tocilizumab therapy in a patient with severe pancytopenia associated with a STAT3 gain-of-function mutation.

BACKGROUND: We aimed to report the clinical characteristics, immunological features, and treatment of one patient with a de novo STAT3 gain-of-function mutation identified by next generation sequencing. We investigated the efficacy of tocilizumab therapy in immune dysregulation diseases caused by STAT3 mutation. RESULTS: The patient was a 16-year-old girl. She presented with recurrent respiratory infections and chronic diarrhea after birth. She had life-threatening autoimmune pancytopenia at 14 years old. After receiving glucocorticoid therapy, she developed diabetes. However, her pancytopenia relapsed when the glucocorticoid was tapered. Next-generation sequencing showed a de novo heterozygous mutation in the STAT3 gene, c.1261G > A (p. G421R), which was previously described as a gain-of-function mutation. After tocilizumab therapy, her pancytopenia fully resolved, and insulin and glucocorticoid therapies were gradually discontinued within 12 months. She had lymphopenia and an inverted CD4/CD8 ratio before therapy. Lymphocyte subpopulation analysis indicated an expansion of effector memory CD4+, effector memory CD8+ and central memory CD4+ T cells. The proportions of memory B cells and naive CD4+ T cells were decreased, and the proportion of naïve B cells was increased. None of the abnormal lymphocytic changes improved significantly. STAT3 GOF mutations were identified by next gene sequencing in those with early-onset multi-organ autoimmunity. Including our patient, 13 patients with STAT3 GOF mutations received targeted treatment. Twelve of them were treated with tocilizumab alone or combination tocilizumab with JAK inhibitor, and ten patients improved. CONCLUSIONS: Gene sequencing should be performed for patients with early-onset refractory or multiorgan immune dysregulation diseases. Targeted drugs can effectively improve the clinical problems associated with STAT3 gain-of-function mutations, while nontargeted immunosuppressive therapy is usually insufficient.

Follicular pathway role in chemical warfare simulants percutaneous penetration.

Chemical warfare (CW) exposure could be fatal to military and civilians through skin contamination. Our work and others focus on investigating stratum corneum reservoir with less regards to skin appendageal routes including hair follicles. Here, C-14 CW simulants (CWS) with specific activity of 0.1 mCi/ml were tested on abdominal and scalp human cadaver skin using flow-through diffusion system. Quantitative analysis of simulants in skin compartments were performed using scintillation counter. Scalp permeation of dipropylene glycol monomethyl ether (DPGME), diisopropyl methylphosphonate (DIMP) and methyl salicylate (MeS) exceed abdominal skin by 8%, 15%, and 6% (p value < 0.05) of applied dose, respectively. DPGME and DIMP (most hydrophilic) showed earlier permeation peak time (Tmax) through scalp skin at 2 and 4 h, respectively, comparing with 6 h with abdominal skin. The percentage of applied dose of DPGME and DIMP retained in human skin membrane (SC, epidermis, and viable dermis) showed no statistically significant difference between tested abdominal and scalp skin samples (p value >0.05). The percentage of applied dose of MeS in scalp showed higher partitioning in stratum corneum and viable epidermis than abdominal skin (p value <0.05). In conclusion, human scalp showed greater total skin absorption than abdominal skin. This work points to a qualitative importance of high follicular density body regions in percutaneous penetration and suggests that transfollicular pathway might have a significant role in early stage permeation of chemical warfare simulants. However, the difference noticed here between scalp and abdominal skin could be attributed to regional variability in anatomy, physiology, and barrier characteristics.

Low-Dose Pioglitazone does not Increase ROS Production in Chronic Granulomatous Disease Patients with Severe Infection.

PURPOSE: We sought to further investigate the efficacy and safety of pioglitazone for chronic granulomatous disease (CGD) patients with severe infection. METHODS: CGD patients with severe infection were enrolled and treated with pioglitazone for 90 days. The degree of improvement in infection and the changes of dihydrorhodamine-123 (DHR) were used to evaluate the efficacy of pioglitazone. The adverse reaction of pioglitazone was also investigated. RESULTS: We planned to enroll 30 patients at first in the study. However, the study was terminated due to negative results from all 3 enrolled patients. The 3 patients were diagnosed with CGD by clinical characteristics, DHR analysis, and genetics analysis. Mutations were CYBB (c.177C>A; p.C59X) in P1, CYBB (c.1498G>T; p.D500Y) in P2, and NCF2 (c.137T>G; p.M46R) in P3, respectively. The age of onset of the 3 patients was within 2 years after birth. The most common sites of infection were lung, lymph node, skin, and soft tissue, which were experienced in all 3 patients. The age of administration with pioglitazone was 5.2 years, 16 years and 11.1 years, respectively. The 3 patients experienced no improvement in severity of infection and stimulation index of the DHR did not also improve after receiving pioglitazone 10, 45 and 90 days, respectively. No drug-related adverse reaction was found during the period of pioglitazone. CONCLUSIONS: Low dose of pioglitazone did not improve the severity of infection and production of ROS in CGD patients with severe infection.

Current Status of the Management of Mendelian Susceptibility to Mycobacterial Disease in Mainland China.

PURPOSE: Although many studies have investigated Mendelian susceptibility to mycobacterial disease (MSMD) worldwide, there is no report of the long-term clinical management and prognosis for MSMD in China. METHODS: This is a cohort study from January 2000 to June 2018. Three hundred and twenty-four patients with bacillus Calmette-Guérin (BCG) infection were diagnosed during this period, and those with MSMD diagnosed by genetic and functional experiments were enrolled in the study. The clinical and genetic characteristics and management of these MSMD patients were summarized. RESULTS: Thirty patients diagnosed with MSMD were followed up. The age at the follow-up end point ranged from 5 to 173 months. Among the patients, IL12RB1 mutations were identified in 22, IFNGR1 mutations in 5, STAT1 mutations in 2, and IFNGR2 mutation in 1. The medium age at onset was 3 months. BCG infection involved multiple organs, including regional infection (8/30; 26.7%) or distant or disseminated infection (22/30; 73.3%). Ten percent (30/324) of patients with BCG infection had a confirmed MSMD diagnosis. Protein expression of IL12RB1 or IFNGR1 was decreased in all patients with IL12RB1 or IFNGR1 mutation, respectively, as indicated by flow cytometry. In addition, 77.8% of patients received rhIFN-γ treatment, which can improve the prognosis of patients with IL12RB1 deficiency. Two patients received stem cell transplantation. Twenty-five patients remained alive at the time of publication. CONCLUSION: MSMD is an important cause of BCG infection. Flow cytometric detection of IL12RB1 and IFNGR1 expression is very useful for rapid MSMD diagnosis. rhIFN-γ therapy is effective in patients with MSMD, particularly improving prognosis in those with IL12RB1 deficiency.

Report of a Chinese Cohort with Leukocyte Adhesion Deficiency-I and Four Novel Mutations.

PURPOSE: We aimed to report the characteristics of leukocyte adhesion deficiency-I (LAD-I) and four novel mutations in the ITGB2 gene in a Chinese cohort. METHODS: Seven patients with LAD-I were reported in our study. Clinical manifestations and immunological phenotypes were reviewed. The expression of CD18 was detected by flow cytometry. Next-generation sequencing (NGS) and Sanger sequencing were performed to identify gene mutations. RESULTS: The mean onset age of all the patients was 1.3 months. Recurrent bacterial infections of the skin and lungs were the most common symptoms. Most patients (6/7) had delayed cord separation. The number of white blood cells (WBC) was increased significantly, except that two patients had a mild increase in the number of WBC during infection-free periods. The expression of CD18 was very low in all patients. Homozygous or compound heterozygous mutations in the ITGB2 gene were identified in each patient. Four mutations were novel, including c.1794dupC (p.N599Qfs*93), c.1788C>A (p.C596X), c.841-849del9, and c.741+1delG. Two patients had large deletions of the ITGB2 gene. Five patients were cured by hematopoietic stem cell transplantation (HSCT). CONCLUSIONS: This study reported the clinical and molecular characteristics of a Chinese patient cohort. It is helpful in understanding the current status of the disease in China.

Novel Heterogeneous Mutation of TNFAIP3 in a Chinese Patient with Behçet-Like Phenotype and Persistent EBV Viremia.

PURPOSE: Tumor necrosis factor alpha-induced protein 3 (TNFAIP3, A20) is a negative regulator of the nuclear factor-κB (NF-κB) pathway. It has recently been recognized that TNFAIP3 deficiency leads to early onset of autoinflammatory and autoimmune syndrome resembling Behçet's disease. Here, we report a novel mutation in TNFAIP3 in a Chinese patient, who had Behçet-like phenotype and persistent Epstein-Barr virus (EBV) viremia. METHODS: The clinical data were collected. Immunological function was detected. Gene mutation was detected by whole-exome sequencing (WES) and confirmed by Sanger sequencing. mRNA and protein levels were detected in the patient under lipopolysaccharide (LPS) stimulation by real-time PCR and Western blot. RESULTS: The patient is a 13-year-old boy, presenting with intermittent fever for 5 months, who also experienced diffuse lymphadenopathy, arthritis, and recurrent multiple gastrointestinal ulcers. EBV DNA was detected in the serum and peripheral blood mononuclear cells of the patient. The immunological phenotype showed increased proportion of double-negative T cells (CD3+CD4-CD8-). A novel missense mutation (c.1428G > A) locating at the zinc fingers 2 (ZF2) domain of TNFAIP3 inherited from his mother was confirmed. Compared with age-matched healthy controls, decrease expression of A20 was observed in the patient. The NF-κB pathway was found to be overactivated, and the synthesis of TNF-α was upregulated in the patient-derived cells. However, cells from the mother showed a milder response to LPS than cells from the patient. CONCLUSIONS: The present research indicated that the TNFAIP3 mutation of c.1428G > A (p.M476I) leads to the reduced suppression of NF-κB activation and accounted for the autoinflammatory phenotype and persistent EBV viremia in the patient.

A Chinese DADA2 patient: report of two novel mutations and successful HSCT.

Deficiency of adenosine deaminase 2 (DADA2) is an autoinflammatory disease caused by autosomal recessive mutations in Cat Eye Syndrome Chromosome Region 1 (CECR1) gene. In this report, we aimed to describe the clinical manifestations, immunological features, genotype, and treatments of one Chinese patient with novel CECR1 gene mutations. This patient initially presented with recurrent fever and rashes from the age of 3 months, but no pathogen was found. She then developed dry gangrene of the fingers at 5 months of age. Laboratory examinations revealed elevated levels of C-reactive protein and thrombocytes. The expression of interleukin-6 (IL-6) and IL-8 were both elevated. Sequencing results revealed that she had compound heterozygous mutations in CECR1 gene (c.1211T>C, p.Phe404Ser and c.1114 G>A, p.Val372Met). Subsequently, treatment with anti-IL-6 (tocilizumab) was started. However, she developed blurred vision in the right eye with occlusion of the central retinal artery, accompanied by unsteady gait. Magnetic resonance imaging (MRI) showed infarction of the right thalamus. Finally, she underwent hematopoietic stem cell transplantation (HSCT) and is currently in remission. Our findings suggest that HSCT could cure this disease.

In Vitro Human Onychopharmacokinetic and Pharmacodynamic Analyses of ME1111, a New Topical Agent for Onychomycosis.

ME1111 is a novel antifungal agent currently under clinical development as a topical onychomycosis treatment. A major challenge in the application of topical onychomycotics is penetration and dissemination of antifungal agent into the infected nail plate and bed. In this study, pharmacokinetic/pharmacodynamic parameters of ME1111 that potentially correlate with clinical efficacy were compared with those of marketed topical onychomycosis antifungal agents: efinaconazole, tavaborole, ciclopirox, and amorolfine. An ME1111 solution and other launched topical formulations were applied to an in vitro dose model for 14 days based on their clinical dose and administration. Drug concentrations in the deep layer of the nail and within the cotton pads beneath the nails were measured using liquid chromatography-tandem mass spectrometry. Concentrations of ME1111 in the nail and cotton pads were much higher than those of efinaconazole, ciclopirox, and amorolfine. Free drug concentrations of ME1111 in deep nail layers and cotton pads were orders of magnitude higher than the MIC90 value against Trichophyton rubrum (n = 30). Unlike other drugs, the in vitro antifungal activity of ME1111 was not affected by 5% human keratin and under a mild acidic condition (pH 5.0). The in vitro antidermatophytic efficacy coefficients (ratio of free drug concentration to MIC90s against T. rubrum) of ME1111, as measured in deep nail layers, were significantly higher than those of efinaconazole, tavaborole, ciclopirox, and amorolfine (P < 0.05). This suggests that ME1111 has excellent permeation of human nails and, consequently, the potential to be an effective topical onychomycosis treatment.

Report of a Chinese Cohort with Activated Phosphoinositide 3-Kinase δ Syndrome.

PURPOSE: We aimed to report the clinical manifestations and immunological features of activated phosphatidylinositol 3-kinase δ syndrome 1 (APDS1) in a Chinese cohort. Moreover, we investigated the efficacy and safety of rapamycin therapy for Chinese patients with APDS1. METHODS: Fifteen Chinese patients with APDS1 from 14 unrelated families were enrolled in this study. These patients were diagnosed based on clinical features, immunological phenotype, and whole-exome sequencing. Four patients were treated with rapamycin, and the clinical efficacy and safety of rapamycin were observed. The changes of phosphorylation of Akt and mammalian target of rapamycin (mTOR) signaling pathway after rapamycin treatment were detected by flow cytometry and real-time PCR. RESULTS: The common clinical manifestations of the patients included lymphadenopathy (93%), recurrent sinopulmonary infections (93%), hepatosplenomegaly (93%), and diarrhea (78%). Epstein-Barr virus (EBV) (80%) and fungus (Aspergillus) (47%) were the most common pathogens. Immunological phenotype included elevated Immunoglobulin (Ig) M levels (100%), decreased naive T cells, increased senescent T cells, and expanded transitional B cells. Whole-exome sequencing indicated that 13 patients had heterogeneous PIK3CD E1021K mutations, 1 patient had heterogeneous E1025G mutation and 1 patient had heterogeneous Y524N mutation. Gain-of-function (GOF) PIK3CD mutations increased the phosphorylation of the Akt-mTOR signaling pathway. Four patients underwent rapamycin therapy, experiencing substantial improvement in clinical symptoms and immunological phenotype. Rapamycin inhibited the activated Akt-mTOR signaling pathway. CONCLUSIONS: We described 15 Chinese patients with APDS1. Treatment with the mTOR inhibitor rapamycin improved patient outcomes.

A Cohort of 169 Chronic Granulomatous Disease Patients Exposed to BCG Vaccination: a Retrospective Study from a Single Center in Shanghai, China (2004-2017).

PURPOSE: Clinical diagnosis and treatment for chronic granulomatous disease (CGD) have advanced greatly in recent years. However, CGD patients in China have unique clinical features and infection spectrums, which are challenging to their caretakers. Here, we summarized the clinical characteristics, genetic features, treatment, and prognosis of CGD in a single center in Shanghai. METHODS: One hundred sixty-nine CGD patients were recruited between January 2004 and May 2017 based on clinical diagnosis. Electronic medical charts were reviewed to collect clinical data. RESULTS: Among the 169 patients recruited, CYBB mutations were identified in 150 cases, whereas CYBA mutations were identified in 7 cases, NCF1 in 5, and NCF2 in 7. The medium age at onset was 1 month (interquartile range 1-3). The medium age at diagnosis was 8 months (interquartile range 3-19). The most common infection sites were the lung (95.9%), lymph node (58.5%), skin (45.4%), intestinal (43.1%), and perianal (38.5%). Bacillus Calmette-Guérin (BCG) infections were common (59.2%). In addition, other non-infectious complications were also common, including anemia (55.4%) and impaired liver functions (34.6%). Thirty-one patients received stem cell transplantation. By the end of this study, 83/131 patients survived. CONCLUSIONS: Similar to other non-consanguineous populations, X-linked CGD accounted for the majority of the cases in China. However, BCG infections were a clinical challenge unique to China. In addition, severe infections were the major cause of death and the overall mortality was still high in China.

Binding affinity and decontamination of dermal decontamination gel to model chemical warfare agent simulants.

Six chemical warfare agent simulants (trimethyl phosphate, dimethyl adipate, 2-chloroethyl methyl sulfide, diethyl adipate, chloroethyl phenyl sulfide and diethyl sebacate) were studied in in vitro human skin to explore relationship between dermal penetration/absorption and the mechanisms of simulant partitioning between stratum corneum (SC) and water as well as between dermal decontamination gel (DDGel) and water. Both binding affinity to and decontamination of simulants using DDGel were studied. Partition coefficients of six simulants between SC and water (Log PSC/w ) and between DDGel and water (Log PDDGel/w ) were determined. Results showed that DDGel has a similar or higher binding affinity to each simulant compared to SC. The relationship between Log P octanol/water and Log PSC/w as well as between Log P octanol/water and Log PDDGel/w demonstrated that partition coefficient of simulants correlated to their lipophilicity or hydrophilicity. Decontamination efficiency results with DDGel for these simulants were consistent with binding affinity results. Amounts of percentage dose of chemicals in DDGel of trimethyl phosphate, dimethyl adipate, 2-chloroethyl methyl sulfide, diethyl adipate, chloroethyl phenyl sulfide and diethyl sebacate were determined to be 61.15, 85.67, 75.91, 53.53, 89.89 and 76.58, with corresponding amounts absorbed in skin of 0.96, 0.65, 1.68, 0.72, 0.57 and 1.38, respectively. In vitro skin decontamination experiments coupled with a dermal absorption study demonstrated that DDGel can efficiently remove chemicals from skin surface, back-extract from the SC, and significantly reduced chemical penetration into skin or systemic absorption for all six simulants tested. Therefore, DDGel offers a great potential as a NextGen skin Decon platform technology for both military and civilian use.

Vehicle effects on human stratum corneum absorption and skin penetration.

This study evaluated the effects of three vehicles-ethanol (EtOH), isopropyl alcohol (IPA), and isopropyl myristate (IPM)-on stratum corneum (SC) absorption and diffusion of the [14C]-model compounds benzoic acid and butenafine hydrochloride to better understand the transport pathways of chemicals passing through and resident in SC. Following application of topical formulations to human dermatomed skin for 30 min, penetration flux was observed for 24 h post dosing, using an in vitro flow-through skin diffusion system. Skin absorption and penetration was compared to the chemical-SC (intact, delipidized, or SC lipid film) binding levels. A significant vehicle effect was observed for chemical skin penetration and SC absorption. IPA resulted in the greatest levels of intact SC/SC lipid absorption, skin penetration, and total skin absorption/penetration of benzoic acid, followed by IPM and EtOH, respectively. For intact SC absorption and total skin absorption/penetration of butenafine, the vehicle that demonstrated the highest level of sorption/penetration was EtOH, followed by IPA and IPM, respectively. The percent doses of butenafine that were absorbed in SC lipid film and penetrated through skin in 24 h were greatest for IPA, followed by EtOH and IPM, respectively. The vehicle effect was consistent between intact SC absorption and total chemical skin absorption and penetration, as well as SC lipid absorption and chemical penetration through skin, suggesting intercellular transport as a main pathway of skin penetration for model chemicals. These results suggest the potential to predict vehicle effects on skin permeability with simple SC absorption assays. As decontamination was applied 30 min after chemical exposure, significant vehicle effects on chemical SC partitioning and percutaneous penetration also suggest that skin decontamination efficiency is vehicle dependent, and an effective decontamination method should act on chemical solutes in the lipid domain.

Antifungal ME1111 in vitro human onychopharmacokinetics.

This study determined ME1111 onychopharmacokinetics and possible topical antifungals' clinical efficacy in human great toenails using an in vitro finite dose model. ME1111 topical formulations in 1, 5, 10 or 15% for 3 days observation and 1, 5 or 10% for 14 days observation, respectively, were used to determine ME1111 penetration rate and transungual kinetics. ME1111 concentrations in the deeper nail (ventral/intermediate layers) and a cotton pad/nail bed, were several orders of magnitude greater than MIC90 and MFC90 for three major dermatophytes. ME1111 concentrations 3 days after a single and 14 days after multiple dosing of 10% formulation were 253 and 7991 µg/g nail, respectively, and superior to those of 8% ciclopirox control. ME1111 concentration (µg equivalent/cm3) in the cotton pad following 10% ME1111 multiple applications increased linearly throughout the 336 h experiment and was significantly greater than that of 8% ciclopirox. Flux rate of ME1111 averaged as 50.9 µg/cm3/day, which was ca. two orders of magnitude greater than the MIC90 values. The novel antifungal ME1111 penetrated well into human nail plate and its concentrations in the deeper nail and cotton pad after application of 10% formulation were significantly greater than those of ciclopirox.

Proposed human stratum corneum water domain in chemical absorption.

Compounds with varying physical and chemical properties may have different affinities to the stratum corneum (SC) and/or its intercellular lipids, keratin protein, and possible water domains. To better understand the mechanism of percutaneous absorption, we utilized 21 carbon-14 labeled chemicals, with wide hydrophilicity (log P = -0.05 to 6.17), and quantified their absorption/adsorption properties for a short incubation time (15 min) with regards to intact SC membrane, delipidized SC membrane and SC lipid. A facile method was developed for SC/lipid absorption, providing a more equivalent procedure and comparable data. SC lipid absorption of chemical solutes positively correlated with the octanol/water partition coefficient (log P). Differences between the percent dose of chemical absorption to intact SC and the total percent dose contributed by the protein and lipid domains suggest the possibility and significance of a water domain. Absorption rate experiments showed a longer lag time for intact SC than for delipidized SC or SC lipid, suggesting that the water domain may delay chemical binding to protein and lipid domains, and may be a factor in the resistance of many chemicals to current decontamination methods. Copyright © 2015 John Wiley & Sons, Ltd.

Effects of soap-water wash on human epidermal penetration.

Skin decontamination is a primary interventional method used to decrease dermal absorption of hazardous contaminants, including chemical warfare agents, pesticides and industrial pollutants. Soap and water wash, the most common and readily available decontamination system, may enhance percutaneous absorption through the "wash-in effect." To understand better the effect of soap-water wash on percutaneous penetration, and provide insight to improving skin decontamination methods, in vitro human epidermal penetration rates of four C(14) -labeled model chemicals (hydroquinone, clonidine, benzoic acid and paraoxon) were assayed using flow-through diffusion cells. Stratum corneum (SC) absorption rates of these chemicals at various hydration levels (0-295% of the dry SC weights) were determined and compared with the results of the epidermal penetration study to clarify the effect of SC hydration on skin permeability. Results showed accelerated penetration curves of benzoic acid and paraoxon after surface wash at 30 min postdosing. Thirty minutes after washing (60 min postdosing), penetration rates of hydroquinone and benzoic acid decreased due to reduced amounts of chemical on the skin surface and in the SC. At the end of the experiment (90 min postdosing), a soap-water wash resulted in lower hydroquinone penetration, greater paraoxon penetration and similar levels of benzoic acid and clonidine penetration compared to penetration levels in the non-wash groups. The observed wash-in effect agrees with the enhancement effect of SC hydration on the SC chemical absorption rate. These results suggest SC hydration derived from surface wash to be one cause of the wash-in effect. Further, the occurrence of a wash-in effect is dependent on chemical identity and elapsed time between exposure and onset of decontamination. By reducing chemical residue quantity on skin surface and in the SC reservoir, the soap-water wash may decrease the total quantity of chemical absorbed in the long term; however, the more immediate accelerated absorption of chemical toxins, particularly chemical warfare agents, may be lethal. Copyright © 2015 John Wiley & Sons, Ltd.

Stratum corneum reservoir as a predictive method for in vitro percutaneous absorption.

Interaction between drug and proteins and lipids in stratum corneum (SC) is an important pharmacokinetic parameter in early steps of absorption. Previous in vivo studies showed that the total amount of compound, regardless of properties, penetrating over a 96 h period could be predicted by the amount present in SC 30 min after application by a linear relationship. Validating this linear relationship through in vitro study would facilitate testing of transdermal drug delivery platforms. We aimed to determine in vitro penetration behavior across SC of humans by determining the relationship between quantity present in SC reservoir 30 min after application with 24 h skin absorption and penetration. In this study, use of the SC reservoir effect to predict absorption and penetration of topical compounds is reaffirmed with in vitro models involving human skin. These results indicate the amount in short-term (30 min) SC reservoir predict long-term (24 h) skin absorption and penetration, as characterized by statistically significant linear relationships determined via regression. This may be explained by the fact that SC is a rate-limiting barrier to percutaneous drug transport. After molecules diffuse through SC barrier, passage into deeper dermal layers and systemic uptake occur relatively quickly. These results enable one to measure quantity in SC reservoir shortly after topical application as a proxy for absorption and penetration over longer periods. With respect to drug development and risk assessment of toxic substances, this may simplify assays attempting to quantitate penetration capacity. Further investigation with a larger range of compounds is needed to clarify the observations recorded here. Copyright © 2015 John Wiley & Sons, Ltd.