A phase 2, open-label study of single-dose dupilumab in children aged 6 months to <6 years with severe uncontrolled atopic dermatitis: pharmacokinetics, safety and efficacy.

BACKGROUND: Dupilumab has demonstrated efficacy and acceptable safety in adults and children (aged 6-17 years) with moderate-to-severe atopic dermatitis (AD), but effective systemic therapy with a favorable risk-benefit profile in younger children remains a significant unmet need. OBJECTIVES: To determine the pharmacokinetics, safety and efficacy of single-dose dupilumab in children with severe AD aged ≥6 months to <6 years. METHODS: This open-label, multicenter, phase 2, sequential, two-age cohort, two-dose level study (LIBERTY AD PRE-SCHOOL; NCT03346434) included an initial cohort of older children aged ≥2 to <6 years, followed by a younger cohort aged ≥6 months to <2 years. Pharmacokinetic sampling, safety monitoring and efficacy assessments were performed during the 4-week period after a single subcutaneous injection of dupilumab, in two sequential dosing groups (3 mg/kg, then 6 mg/kg). The use of standardized, low-to-medium potency topical corticosteroids was allowed. RESULTS: Forty patients were enrolled (20/age cohort, 10/dose level within a cohort) between December 20, 2017 and July 22, 2019. Within each age cohort, pharmacokinetic exposures after a single injection of dupilumab increased in a greater than dose-proportional manner. At week 3, treatment with 3 and 6 mg/kg dupilumab reduced scores of mean Eczema Area and Severity Index by -44.6% and -49.7% (older cohort) and -42.7% and -38.8% (younger cohort), and mean Peak Pruritus NRS scores by -22.9% and -44.7% (older cohort) and -11.1% and -18.2% (younger cohort), respectively. At week 4, improvements in most efficacy outcomes diminished in both age groups, particularly with the lower dose. The safety profile was comparable to that seen in adults, adolescents and children. CONCLUSIONS: Single-dose dupilumab was generally well tolerated and substantially reduced clinical signs/symptoms of AD. Slightly better responses were seen in older than younger children. The pharmacokinetics of dupilumab were non-linear, consistent with previous studies in adults and adolescents.

Laboratory safety of dupilumab in moderate-to-severe atopic dermatitis: results from three phase III trials (LIBERTY AD SOLO 1, LIBERTY AD SOLO 2, LIBERTY AD CHRONOS).

BACKGROUND: Dupilumab [a monoclonal antibody blocking the shared receptor subunit for interleukin (IL)-4 and IL-13] is approved for patients aged ≥ 12 years with inadequately controlled, moderate-to-severe atopic dermatitis (AD). Dupilumab trials of up to 52 weeks demonstrated efficacy and a favourable safety profile in patients with moderate-to-severe AD inadequately controlled with topical medications. OBJECTIVES: To further characterize the safety of dupilumab by evaluating clinical laboratory findings from three randomized, double-blinded, placebo-controlled phase III trials (LIBERTY AD SOLO 1 & 2 and LIBERTY AD CHRONOS). METHODS: Patients were randomized 1 : 1 : 1 (SOLO 1 & 2) or 3 : 1 : 3 (CHRONOS) for 16 and 52 weeks, respectively, to dupilumab weekly, every 2 weeks or placebo. CHRONOS patients received a standardized concomitant topical corticosteroid regimen. Laboratory outcomes were summarized descriptively in 1376 patients from SOLO 1 & 2 and 740 from CHRONOS. RESULTS: Treatment groups had similar results in baseline laboratory parameters. Platelets and neutrophils showed mild decreases from baseline in dupilumab vs. placebo groups. Some dupilumab-treated patients had small transient increases in eosinophils. Grade 3 eosinophilia was reported in < 1% of dupilumab-treated and placebo-treated patients; no adverse events were associated with eosinophilia. Lactate dehydrogenase levels decreased from baseline during dupilumab treatment in all trials. No clinically meaningful changes were observed between treatment groups in other haematology, chemistry or urinalysis parameters. CONCLUSIONS: There were no clinically important changes in routine laboratory parameters that could be attributed to dupilumab. This study supports the use of dupilumab as a systemic treatment for moderate-to-severe AD that does not require laboratory monitoring. What's already known about this topic? Long-term treatment of atopic dermatitis (AD) with conventional immunosuppressive agents is limited by the risk of significant side-effects and a need for repeated tests to monitor haematological and/or organ (e.g. liver, kidney) toxicities. Dupilumab [a monoclonal antibody blocking the shared receptor subunit for interleukin (IL)-4 and IL-13] is approved for the treatment of patients with inadequately controlled, moderate-to-severe AD. In 16-week and 52-week studies, dupilumab demonstrated a positive risk/benefit profile in moderate-to-severe AD. What does this study add? This study is the first comprehensive analysis of dupilumab laboratory safety data of the 16-week SOLO 1 & 2 (pooled N = 1376) and 52-week CHRONOS (N = 740) trials, demonstrating an absence of clinically important changes in haematology, serum chemistry and urinalysis parameters in patients with moderate-to-severe AD treated with dupilumab. Our data support the use of dupilumab as a systemic treatment for the long-term management of moderate-to-severe AD without routine laboratory monitoring in clinical practice.

Assessing the need for routine safety testing for patients being treated with dupilumab for moderate-to-severe atopic dermatitis.

Atopic dermatitis (also known as AD or eczema) is a common skin disease that can cause intense and persistent itching and rashes. Skin creams or ointments are not suitable or effective for some patients with moderate-to-severe AD. In these patients, oral (taken by mouth) or injected medications may be required. Some of those oral or injected treatments could be toxic and often have unwanted side effects, especially when used for a longer period of time, so patients must be regularly tested to see whether those treatments are harming their blood or organs. Dupilumab is a newer injectable drug for treating moderate-to-severe AD. Dupilumab specifically targets key molecules in the body that cause AD. Dupilumab has been tested for up to one year in more than 2000 patients enroled in placebo-controlled clinical trials. During those trials, patients provided blood and urine samples for laboratory testing while they were being treated with dupilumab or placebo (dummy drug). In this paper, the authors from Germany and the U.S.A, analysed how blood cells, blood chemistry, and urine chemistry changed during treatment, to check whether dupilumab is safe to use without the need for regular laboratory tests. After performing many routine laboratory tests on patients' blood and urine, they found that there were no clinically important changes in test results that could be linked to dupilumab. They concluded that patients using dupilumab for moderate-to-severe AD do not need routine laboratory testing. This is a summary of the study: Laboratory safety of dupilumab in moderate-to-severe atopic dermatitis: results from three phase III trials (LIBERTY AD SOLO 1, LIBERTY AD SOLO 2, LIBERTY AD CHRONOS).

Dupilumab in adolescents with uncontrolled moderate-to-severe atopic dermatitis: results from a phase IIa open-label trial and subsequent phase III open-label extension.

BACKGROUND: Dupilumab (monoclonal antibody inhibiting IL-4/IL-13 signalling) is approved for use in adolescents aged ≥ 12 years with inadequately controlled moderate-to-severe atopic dermatitis (AD). Dupilumab significantly improved AD signs/symptoms in a 16-week, randomised, placebo-controlled phase III trial in adolescents (NCT03054428). OBJECTIVES: To characterize the pharmacokinetics of dupilumab, and long-term safety and efficacy in adolescents. METHODS: This was a global, multicentre, phase IIa, open-label, ascending-dose, sequential cohort study with a phase III open-label extension (OLE) in adolescents with moderate-to-severe AD. In the phase IIa study, patients received one dupilumab dose (2 mg kg-1 or 4 mg kg-1 ) and 8 weeks of pharmacokinetic sampling. Thereafter, patients received the same dose weekly for 4 weeks, with 8-week safety follow-up. Patients then enrolled in the OLE, continuing 2 mg kg-1 or 4 mg kg-1 dupilumab weekly. Primary end points were dupilumab concentration-time profile and incidence of treatment-emergent adverse events (TEAEs). Secondary outcomes included Eczema Area and Severity Index (EASI). RESULTS: Forty adolescents received dupilumab in the phase IIa study; 36 enrolled in the OLE. Dupilumab showed nonlinear, target-mediated pharmacokinetics. Mean ± SD trough dupilumab concentrations in serum at week 48 (OLE) were 74 ± 19 mg L-1 and 161 ± 60 mg L-1 for 2 mg kg-1 and 4 mg kg-1 , respectively. Dupilumab was well tolerated over 52 weeks; the most common TEAEs were nasopharyngitis (week 52: 41% [2 mg kg-1 ], 47% [4 mg kg-1 ]) and AD exacerbation (29%, 42%). After one dupilumab dose in the phase IIa study, EASI improved from baseline to week 2 [mean ± SD reduction -34% ± 20% (2 mg kg-1 ) and -51% ± 29% (4 mg kg-1 )]. With continuing treatment, EASI scores improved further [week 52: -85% ± 12% (2 mg kg-1 ) and -84% ± 20% (4 mg kg-1 )]. CONCLUSIONS: In adolescents with moderate-to-severe AD, dupilumab's pharmacokinetic profile was similar to that in adults. These 52-week safety and efficacy data support long-term use of dupilumab in this patient population. What's already known about this topic? Adolescents with moderate-to-severe atopic dermatitis (AD) have high unmet medical need, with significant disease burden and limited treatment options. Dupilumab (monoclonal antibody against interleukin-4 receptor α) is approved for the treatment of adolescents with moderate-to-severe AD who are inadequately responsive to standard of care (U.S.A.) or candidates for systemic therapy (European Union). A 16-week, randomized, placebo-controlled phase III trial in adolescents demonstrated significant improvements in AD signs/symptoms with an acceptable safety profile. What does this study add? These studies demonstrate the long-term safety and efficacy of dupilumab in adolescents with moderate-to-severe AD for up to 52 weeks of treatment, thus extending and reinforcing the findings from the 16-week dupilumab phase III trial. The data from these studies also support the use of dupilumab in combination with current standard of care (topical corticosteroids), which was not evaluated in the 16-week phase III monotherapy trial.

Dupilumab provides important clinical benefits to patients with atopic dermatitis who do not achieve clear or almost clear skin according to the Investigator's Global Assessment: a pooled analysis of data from two phase III trials.

BACKGROUND: In the U.S.A., an Investigator's Global Assessment (IGA) score of ≤ 1 (clear or almost clear skin) has been the standard measure in regulatory outcomes for registration clinical trials in atopic dermatitis (AD), including those supporting the recent approval of dupilumab. OBJECTIVES: To evaluate the treatment effect of dupilumab in patients with IGA > 1 at the end of treatment, using other validated outcome measures for AD signs, symptoms and quality of life. METHODS: LIBERTY AD SOLO 1 and 2 were two 16-week, randomized, double-blind trials enrolling adult patients with moderate-to-severe AD (IGA ≥ 3) inadequately controlled with topical treatment. We performed a post hoc analysis in patients receiving dupilumab 300 mg every 2 weeks (q2w) or placebo. Outcome measures in patients with IGA > 1 included Eczema Area and Severity Index (EASI), pruritus numerical rating scale (NRS), affected body surface area (BSA), Patient-Oriented Eczema Measure (POEM) and Dermatology Life Quality Index (DLQI). The trials were registered at ClinicalTrials.gov: NCT02277743 and NCT02277769. RESULTS: At week 16, 278 of 449 dupilumab q2w-treated patients (median age 36·0 years) and 396 of 443 placebo-treated patients had IGA > 1. Among patients with IGA > 1 at week 16, dupilumab significantly improved several outcome measures compared with placebo: EASI (-48·9% vs. -11·3%, P < 0·001), pruritus NRS (-35·2% vs. -9·1%, P < 0·001), affected BSA (-23·1% vs. -4·5%, P < 0·001), POEM score ≥ 4-point improvement (57·4% vs. 21·0%, P < 0·001) and DLQI score ≥ 4-point improvement (59·3% vs. 24·4%, P < 0·001). CONCLUSIONS: In patients with IGA > 1 at week 16, dupilumab induced statistically significant benefits in multiple validated outcome measures compared with placebo. The IGA ≤ 1 end point significantly underestimates clinically relevant dupilumab treatment effects.

Peak Pruritus Numerical Rating Scale: psychometric validation and responder definition for assessing itch in moderate-to-severe atopic dermatitis.

BACKGROUND: Moderate-to-severe atopic dermatitis (AD) is a chronic disease characterized by intense, persistent and debilitating itch, resulting in sleep deprivation, signs of anxiety and depression, impaired quality of life and reduced productivity. The Peak Pruritus Numerical Rating Scale (NRS) was developed and validated as a single-item, patient-reported outcome (PRO) of itch severity. OBJECTIVES: To describe the content validity and psychometric assessment (test-retest reliability, construct validity, known-groups validity, sensitivity to change) of the Peak Pruritus NRS, and to derive empirically a responder definition to identify adults with a meaningful change in itch. METHODS: Content validity was assessed through in-depth patient interviews. Psychometric assessments used data from phase IIb and phase III dupilumab clinical trials and included test-retest reliability, construct validity, known-groups validity and sensitivity to change in patients with moderate-to-severe AD. RESULTS: Interview participants indicated that the Peak Pruritus NRS was a relevant, clear and comprehensive assessment of itch severity. Peak Pruritus NRS scores showed large, positive correlations with existing PRO measures of itch, and weak or moderate correlations with clinician-reported measures assessing objective signs of AD. Peak Pruritus NRS score improvements were highly correlated with improvements in other itch PROs, and moderately correlated with improvements in clinician-reported measures assessing objective signs of AD. The most appropriate threshold for defining a clinically relevant, within-person response was ≥ 2-4-point change in the Peak Pruritus NRS. CONCLUSIONS: The Peak Pruritus NRS is a well-defined, reliable, sensitive and valid scale for evaluating worst itch intensity in adults with moderate-to-severe AD.

Conjunctivitis in dupilumab clinical trials.

BACKGROUND: Dupilumab blocks the shared receptor component for interleukin (IL)-4 and IL-13. It is approved in the U.S.A. for patients aged ≥ 12 years with moderate-to-severe atopic dermatitis (AD) uncontrolled by topical prescription medicines or who cannot use topical medicines, for patients in Japan whose AD is uncontrolled with existing therapies, for patients with moderate-to-severe AD in Europe who are candidates for systemic therapy and for patients aged ≥ 12 years for maintenance treatment of moderate-to-severe asthma uncontrolled with their current medicines. AD trials have reported increased incidence of conjunctivitis for dupilumab vs. placebo. OBJECTIVES: To characterize further the occurrence and risk factors of conjunctivitis in dupilumab clinical trials. METHODS: We evaluated randomized placebo-controlled trials of dupilumab in AD (n = 2629), asthma (n = 2876), chronic rhinosinusitis with nasal polyps (CRSwNP) (n = 60) and eosinophilic oesophagitis (EoE) (n = 47). RESULTS: In most AD trials, dupilumab-treated patients had higher conjunctivitis incidence than placebo controls. Higher baseline AD severity and previous history of conjunctivitis were associated with increased conjunctivitis incidence. Conjunctivitis was mostly mild to moderate. Most cases recovered or resolved during the treatment period; two patients permanently discontinued dupilumab due to conjunctivitis or keratitis. Common treatments included ophthalmic corticosteroids, antibiotics, and antihistamines or mast cell stabilizers. Most cases were diagnosed by the investigators. In asthma and CRSwNP trials, the incidence of conjunctivitis was lower for both dupilumab and placebo than in AD trials; dupilumab did not increase the incidence compared with placebo. In the EoE trial, no patients had conjunctivitis. CONCLUSIONS: Conjunctivitis was more frequent with dupilumab treatment in most AD trials. In dupilumab trials in other type 2 diseases, incidence of conjunctivitis was overall very low, and was similar for dupilumab and placebo. In AD, the incidence of conjunctivitis was associated with AD severity and prior history of conjunctivitis. The aetiology and treatment of conjunctivitis in dupilumab-treated patients require further study. What's already known about this topic? Ocular disorders, including allergic conjunctivitis, are common in patients with atopic dermatitis (AD). In most dupilumab AD trials, dupilumab-treated patients had higher conjunctivitis incidence than those receiving placebo. Most cases were mild to moderate and recovered or were recovering during study treatment; study treatment discontinuation due to conjunctivitis was rare. Conjunctivitis incidence was very low and similar for dupilumab and placebo in clinical trials in asthma, chronic rhinosinusitis with nasal polyps and eosinophilic oesophagitis. What does this study add? This analysis confirms and extends the results of the individual clinical trials. Baseline disease-related factors, including AD severity, prior conjunctivitis history and certain biomarkers (thymus and activation-regulated chemokine, IgE, eosinophils), were associated with increased incidence of conjunctivitis. Patients who responded well to dupilumab had reduced incidence of conjunctivitis. Further study is needed to elucidate the aetiology and treatment of conjunctivitis in dupilumab-treated patients with AD.

Dupilumab with concomitant topical corticosteroid treatment in adults with atopic dermatitis with an inadequate response or intolerance to ciclosporin A or when this treatment is medically inadvisable: a placebo-controlled, randomized phase III clinical trial (LIBERTY AD CAFÉ).

BACKGROUND: Atopic dermatitis is a chronic inflammatory skin disease that may require systemic therapy. Ciclosporin A (CsA) is a widely used, potent immunosuppressant but it is not effective in all patients with atopic dermatitis, and side-effects limit its use. Dupilumab, a fully human anti-interleukin 4 receptor-alpha monoclonal antibody, inhibits signaling of IL-4 and IL-13, key drivers of Type 2/Th2-mediated inflammation, and is approved in the U.S.A. and the European Union for the treatment of inadequately-controlled moderate-to-severe atopic dermatitis in adults. OBJECTIVES: To evaluate efficacy and safety of dupilumab with concomitant topical corticosteroids (TCS) in adults with atopic dermatitis with inadequate response to/intolerance of CsA, or for whom CsA treatment was medically inadvisable. METHODS: In this 16-week, double-blind, randomized, placebo-controlled, phase III trial, patients were randomized 1 : 1 : 1 to subcutaneous dupilumab 300 mg weekly (qw) or every 2 weeks (q2w) or placebo. All received concomitant medium-potency TCS from Week -2 through Week 16; dosage could be tapered if lesions cleared, or stopped for adverse reactions to TCS. RESULTS: In total, 390 patients were screened, 325 were randomized, and 318 completed the trial. Treatment groups had similar baseline characteristics. Significantly more patients in the dupilumab qw + TCS and q2w + TCS groups achieved ≥ 75% improvement from baseline in the Eczema Area and Severity Index at Week 16 vs. the placebo + TCS group (primary end point) (59·1% and 62·6% vs. 29·6%, respectively; P < 0·001 vs. placebo + TCS, both doses). Other clinical outcomes and atopic dermatitis symptoms were significantly improved in the dupilumab qw + TCS and q2w + TCS groups, including pruritus, pain, sleep disturbance, symptoms of anxiety and depression, and quality of life (QoL). Treatment groups had similar overall rates of adverse events (qw + TCS, q2w + TCS and placebo + TCS groups: 69·1%, 72·0% and 69·4%, respectively) and serious adverse events (1·8%, 1·9% and 1·9%, respectively). Conjunctivitis was more frequent with dupilumab + TCS; skin infections were more frequent with placebo + TCS. CONCLUSIONS: Dupilumab + TCS significantly improved signs and symptoms of atopic dermatitis and QoL in adults with a history of inadequate response to/intolerance of CsA, or for whom CsA treatment was medically inadvisable. No new safety signals were identified.

Expression and functional role of CRIPTO-1 in cutaneous melanoma.

BACKGROUND: CRIPTO-1 (CR-1) is involved in the pathogenesis and progression of human carcinoma of different histological origin. In this study we addressed the expression and the functional role of CR-1 in cutaneous melanoma. METHODS: Expression of CR-1 protein in melanomas and melanoma cell lines was assessed by immunohistochemistry, western blotting and/or flow cytometry. Levels of mRNA were evaluated by real-time PCR. Invasion assays were performed in Matrigel-coated modified Boyden chambers. RESULTS: Expression of CR-1 protein and/or mRNA was found in 16 out of 37 primary human cutaneous melanomas and in 12 out of 21 melanoma cell lines. Recombinant CR-1 protein activated in melanoma cells c-Src and, at lesser extent, Smad signalling. In addition, CR-1 significantly increased the invasive ability of melanoma cells that was prevented by treatment with either the ALK4 inhibitor SB-431542 or the c-Src inhibitor saracatinib (AZD0530). Anti-CR-1 siRNAs produced a significant inhibition of the growth and the invasive ability of melanoma cells. Finally, a close correlation was found in melanoma cells between the levels of expression of CR-1 and the effects of saracatinib on cell growth. CONCLUSION: These data indicate that a significant fraction of cutaneous melanoma expresses CR-1 and that this growth factor is involved in the invasion and proliferation of melanoma cells.

Ecto-mesenchymal stem cells from dental pulp are committed to differentiate into active melanocytes.

Dental pulp stem cells (DPSCs) are multipotent stem cells derived from neural crest and mesenchyme and have the capacity to differentiate into multiple cell lineages. It has already been demonstrated that DPSCs differentiate into melanocyte-like cells but only when cultivated in a specific melanocyte differentiating medium. In this study we have shown, for the first time, that DPSCs are capable of spontaneously differentiating into mature melanocytes, which display molecular and ultrastructural features of full development, including the expression of melanocyte specific markers and the presence of melanosomes up to the terminal stage of maturation. We have also compared the differentiating features of DPSCs grown in different culture conditions, following the timing of differentiation at molecular and cytochemical levels and found that in all culture conditions full development of these cells was obtained, although at different times. The spontaneous differentiating potential of these cells strongly suggests their possible applications in regenerative medicine.

Human postnatal dental pulp cells co-differentiate into osteoblasts and endotheliocytes: a pivotal synergy leading to adult bone tissue formation.

Stromal stem cells from human dental pulp (SBP-DPSCs) were used to study osteogenic differentiation in vitro and in vivo. We previously reported that SBP-DPSCs are multipotent stem cells able to differentiate into osteoblasts, which synthesize three-dimensional woven bone tissue chips in vitro. In this study, we followed the temporal expression pattern of specific markers in SBP-DPSCs and found that, when differentiating into osteoblasts, they express, besides osteocalcin, also flk-1 (VEGF-R2). In addition, 30% of them expressed specific antigens for endothelial cells, including CD54, von-Willebrand (domain 1 and 2), CD31 (PECAM-1) and angiotensin-converting enzyme. Interestingly, we found endotheliocytes forming vessel walls, observing that stem cells synergically differentiate into osteoblasts and endotheliocytes, and that flk-1 exerts a pivotal role in coupling osteoblast and endotheliocyte differentiation. When either SBP-DPSCs or bone chips obtained in vitro were transplanted into immunocompromised rats, they generated a tissue structure with an integral blood supply similar to that of human adult bone; in fact, a large number of HLA-1+ vessels were observed either within the bone or surrounding it in a periosteal layer. This study provides direct evidence to suggest that osteogenesis and angiogenesis mediated by human SBP-DPSCs may be regulated by distinct mechanisms, leading to the organization of adult bone tissue after stem cell transplantation.

The stem cell hypothesis in head and neck cancer.

Cancer stem cells (CSCs) are tumoral cells which have stem features such as self-renewal, high migration capacity, drug resistance, high proliferation abilities. In the last 10 years the pathological meaning and the existence of CSCs have been matter of discussion and a large number of articles have been published about the role that these cells play in the development and maintenance of the tumors. Head and neck squamous-cell carcinoma (HNSCC) is the sixth most common cancer worldwide: early diagnosis of high-risk premalignant lesions are high priorities for reducing deaths due to head and neck cancer. In the last years the CSCs hypothesis has been faced also for head and neck cancer, with the aim of a better comprehension of the tumor biology and an early diagnosis. The evidence that the development of a tumor comes from a small number of cells with stem-like characteristic, could bring too to the identification of therapies against these cellular target, fundamental for maintenance and progression of the lesion. Here, a literature review has been reported about the detection of supposed CSCs in head and neck cancer.

Capsule endoscopy in patients with chronic abdominal pain.

BACKGROUND: Patients with chronic abdominal pain consult gastroenterologists frequently, requiring a large number of examinations. AIM: To assess the diagnostic yield of capsule endoscopy in patients with chronic abdominal pain of unknown origin and negative diagnostic work-up. PATIENTS: From January 2002 to September 2004, 16 patients (10 female; mean age 42.7 years) who complained of chronic abdominal pain were referred to our unit for capsule endoscopy. METHODS: Chronic abdominal pain was defined as continuous or almost continuous, for at least 3 months and without criteria for other gastrointestinal disorders. All patients had a previous diagnostic work-up including abdominal ultrasonography, oesophagogastroduodenoscopy, colonoscopy and small bowel follow through, performed within 2 months. RESULTS: Capsule endoscopy was normal in 12 patients (75%). Small bowel abnormalities were found in three patients, but were considered irrelevant. In one patient (6.3%), capsule endoscopy revealed ileal erosions and inflammation and was retained in a stricture undetected by radiology. This patient underwent elective surgery which revealed an ileal carcinoid neoplasm. CONCLUSIONS: Capsule endoscopy identified a specific cause of chronic abdominal pain in only one patient. Capsule endoscopy is a safe procedure but does not seem to play an important role in the evaluation of patients with chronic abdominal pain of unknown origin.

Characterizing Class I WW domains defines key specificity determinants and generates mutant domains with novel specificities.

INTRODUCTION: WW domains are small protein interaction modules found in a wide range of eukaryotic signaling and structural proteins. Five classes of WW domains have been annotated to date, where each class is largely defined by the type of peptide ligand selected, rather than by similarities within WW domains. Class I WW domains bind Pro-Pro-Xxx-Tyr containing ligands, and it would be of interest to determine residues within the domains that determine this specificity. RESULTS: Fourteen WW domains selected Leu/Pro-Pro-Xxx-Tyr containing peptides ligands via phage display and were thus designated as Class 1 WW domains. These domains include those present in human YAP (hYAP) and WWP3, as well as those found in ubiquitin protein ligases of the Nedd4 family, including mouse Nedd4 (mNedd4), WWP1, WWP2 and Rsp5. Comparing the primary structures of these WW domains highlighted a set of highly conserved residues, in addition to those originally noted to occur within WW domains. Substitutions at two of these conserved positions completely inhibited ligand binding, whereas substitution at a non-conserved position did not. Moreover, mutant WW domains containing substitutions at conserved positions bound novel peptide ligands. CONCLUSIONS: Class I WW domains contain a highly conserved set of residues that are important in selecting Pro-Xxx-Tyr containing peptide ligands. The presence of these residues within an uncharacterized WW domain can be used to predict its ability to bind Pro-Xxx-Tyr containing peptide ligands.

Localization of ribophorin II to the endoplasmic reticulum involves both its transmembrane and cytoplasmic domains.

Proteins that are concentrated in specific compartments of the endomembrane system in order to exert their organelle-specific function must possess specific localization signals that prevent their transport to distal regions of the exocytic pathway. Some resident proteins of the endoplasmic reticulum (ER) that are known to escape with low efficiency from this organelle to a post ER compartment are recognized by a recycling receptor and brought back to their site of residence. Other ER proteins, however, appear to be retained in the ER by mechanisms that operate in the organelle itself. The mammalian oligosaccharyltransferase (OST) is a protein complex that effects the cotranslational N-glycosylation of newly synthesized polypeptides, and is composed of at least four rough ER-specific membrane proteins: ribophorins I and II (RI and RII), OST48, and Dadl. The mechanism(s) by which the subunits of this complex are retained in the ER are not well understood. In an effort to identify the domains within RII responsible for its ER localization we have studied the fate of chimeric proteins in which one or more RII domains were replaced by the corresponding ones of the Tac antigen, the latter being a well characterized plasma membrane protein that lacks intrinsic ER retention signals and serves to provide a neutral framework for the identification of retention signals in other proteins. We found that the luminal domain of RII by itself does not contain retention information, while the cytoplasmic and transmembrane domains contain independent ER localization signals. We also show that the retention function of the transmembrane domain is strengthened by the presence of a flanking luminal region consisting of 15 amino acids.

Common human leukocyte antigen alleles in pemphigus vulgaris and pemphigus foliaceus Italian patients.

Pemphigus refers to a group of autoimmune blistering skin diseases, mainly identified as pemphigus vulgaris and pemphigus foliaceus, both characterized by the presence of autoantibodies against keratinocyte adhesion molecules, leading to loss of cell-cell adhesion with consequent blister formation. Pemphigus vulgaris is reported to be associated with human leukocyte antigen DR4 and/or DR6 whereas no data are available on pemphigus foliaceus, except for the endemic Brazilian form (fogo selvagem), which is reported to be associated with DR1 and DR4. We here report human leukocyte antigen molecular typing on a total of 87 patients, 61 with pemphigus vulgaris and 26 with pemphigus foliaceus, versus 128 healthy matched controls. Generic typing showed an increase of DRB1*04 and DRB1*14 and a decrease of DRB1*07 in both pemphigus vulgaris and pemphigus foliaceus patients. Molecular subtyping of DR4+ and DR14+ subjects showed a highly significant association between the DRB1*1401 and both pemphigus vulgaris (p < 0.0001) and pemphigus foliaceus patients (p < 0.0001) together with a significant increase of the linked DQB1*0503 (pemphigus vulgaris p < 0.0001; pemphigus foliaceus p < 0.0001). Moreover, whereas the association between DRB1*0402 and pemphigus vulgaris (p < 0.0001) has been confirmed, no significant association between a specific allele of the DR4 group and pemphigus foliaceus, has been found. Therefore, at least in Italian patients, pemphigus vulgaris and pemphigus foliaceus share DRB1*1401 and DQB1*0503, as susceptible human leukocyte antigen alleles, whereas DRB1*0402 is only found associated with pemphigus vulgaris. The observation that both diseases, pemphigus vulgaris and pemphigus foliaceus, carry the same susceptible human leukocyte antigen alleles has been interpreted as a common genetic background predisposing to pemphigus as, like in other autoimmune disorders, it is not sufficient to explain the onset of the disease on the basis of the sole aforementioned alleles. Other linked genes and/or environmental factors should play a facilitating role in the outbreak of pemphigus, either pemphigus vulgaris or pemphigus foliaceus.

HLA-DRB1*1501 and response to copolymer-1 therapy in relapsing-remitting multiple sclerosis.

BACKGROUND: Copolymer 1 (Cop-1) is a random synthetic amino acid copolymer, effective in the treatment of the relapsing-remitting form of MS (RRMS). In vitro and in vivo studies suggest that the mechanism of Cop-1 involves its binding to major histocompatibility complex class II molecules as an initial step. OBJECTIVE: To assess a possible relationship between human leukocyte antigen (HLA) alleles and response to Cop-1 therapy. METHODS: Eighty-three patients with RRMS, 44 treated with Cop-1 and 39 with interferon beta-1a (IFNbeta-1a) for 2 years, were typed by molecular methods for HLA class II genes and subgrouped according to clinical outcome. RESULTS: Data have shown a possible positive correlation between presence of DRB1*1501 and response to Cop-1 therapy (p = 0.008). No relationship between HLA alleles and therapy has been found in IFNbeta-1a treated patients. CONCLUSIONS: Results suggest that DRB1*1501 might be relevant for the clinical outcome in Cop-1 treated patients and, if confirmed in larger studies, it could be helpful in the selection of RRMS patients for different therapeutic options.

Crohn disease: susceptibility and disease heterogeneity revealed by HLA genotyping.

Predisposition to Crohn disease (CD) seems to be genetically determined but, though several reports on the matter, the association between HLA antigens and the disease is still controversial. PCR-SSP high resolution typing in 107 CD patients, and in subgroups selected according to clinical features, showed a positive association with the rare haplotype DRB1*07, DQB1*0303 both in the overall patients (p = 0.002; pc = ns) and in the subgroup of nonfistulized patients (p = 0.0008; pc = 0.032). Moreover, the protective role of the haplotype DRB1*03, DQB1*0201 (p = 0.029) was confirmed also in Italian patients, whereas no strong association with HLA class I alleles has been found. In addition, variability of the HLA alleles frequency in CD subgroups was observed, supporting the hypothesis of a genetic heterogeneity of the disease and suggesting that HLA alleles distribution in selected groups may allow to identify patients with probably different prognosis or associated complications.