Cancer regression and autoimmunity induced by cytotoxic T lymphocyte-associated antigen 4 blockade in patients with metastatic melanoma

Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) is a critical immunoregulatory molecule (expressed on activated T cells and a subset of regulatory T cells) capable of down-regulating T cell activation. Blockade of CTLA-4 has been shown in animal models to improve the effectiveness of cancer immunotherapy. We thus treated 14 patients with metastatic melanoma by using serial i.v. administration of a fully human anti-CTLA-4 antibody (MDX-010) in conjunction with s.c. vaccination with two modified HLA-A*0201-restricted peptides from the gp100 melanoma-associated antigen, gp100:209-217(210M) and gp100:280-288(288V). This blockade of CTLA-4 induced grade III/IV autoimmune manifestations in six patients (43%), including dermatitis, enterocolitis, hepatitis, and hypophysitis, and mediated objective cancer regression in three patients (21%; two complete and one partial responses). This study establishes CTLA-4 as an important molecule regulating tolerance to "self" antigens in humans and suggests a role for CTLA-4 blockade in breaking tolerance to human cancer antigens for cancer immunotherapy.

Essential involvement of interleukin-8 (IL-8) in acute inflammation

Neutrophil infiltration into inflammatory sites is one of the hallmarks of acute inflammation. Locally produced chemotactic factors are presumed to mediate the sequence of events leading to the infiltration at inflammatory sites. Interleukin-8 (IL-8), a novel leukocyte chemotactic activating cytokine (chemokine), is produced by various types of cells upon stimulation with inflammatory stimuli and exerts a variety of functions on leukocytes, particularly, neutrophils in vitro. However, no definitive evidence has been presented on its role in recruiting and activating neutrophils in the lesions of various types of inflammatory reactions. We administered a highly specific neutralizing antibody against IL-8 in several types of acute inflammatory reactions, including lipopolysaccharide (LPS)-induced dermatitis, LPS/IL-1-induced arthritis, lung reperfusion injury, and acute immune complex-type glomerulonephritis. Anti-IL-8 treatment prevented neutrophil-dependent tissue damage as well as neutrophil infiltration in these conditions. These results suggest that IL-8 plays a causative role in acute inflammation by recruiting and activating neutrophils.

Keratinocytes as initiators of inflammation

Environmental stimuli responsible for inducing cutaneous inflammation include contact allergens and ultraviolet light. We postulate that these diverse stimuli trigger a cutaneous inflammatory response by directly inducing epidermal keratinocytes to elaborate specific pro-inflammatory cytokines and adhesion molecules. The consequences are activation of dermal microvascular endothelial cells and selective accumulation of specific mononuclear cells in the dermis and epidermis. Thus, keratinocytes may act as "signal transducers", capable of converting exogenous stimuli into the production of cytokines, adhesion molecules, and chemotactic factors (acting in an autocrine and paracrine fashion) responsible for initiation of "antigen-independent" cutaneous inflammation. The initiation phase may facilitate or promote an amplification phase with additional production of tumour-necrosis factor alpha and interferon gamma via an "antigen-dependent" pathway, and keratinocyte/T cell/antigen-presenting dendritic cellular associations. The direct activation of keratinocytes, with their ability to produce the complete repertoire of pro-inflammatory cytokines, can profoundly influence endogenous and recruited immunocompetent cells, thereby providing the critical trigger responsible for the swift and clinically dramatic alterations that occur following contact between the epidermis and a host of "noxious" agents.

Photocrosslinked hyaluronic acid hydrogels: natural, biodegradable tissue engineering scaffolds

Ideally, rationally designed tissue engineering scaffolds promote natural wound healing and regeneration. Therefore, we sought to synthesize a biomimetic hydrogel specifically designed to promote tissue repair and chose hyaluronic acid (HA; also called hyaluronan) as our initial material. Hyaluronic acid is a naturally occurring polymer associated with various cellular processes involved in wound healing, such as angiogenesis. Hyaluronic acid also presents unique advantages: it is easy to produce and modify, hydrophilic and nonadhesive, and naturally biodegradable. We prepared a range of glycidyl methacrylate-HA (GMHA) conjugates, which were subsequently photopolymerized to form crosslinked GMHA hydrogels. A range of hydrogel degradation rates was achieved as well as a corresponding, modest range of material properties (e.g., swelling, mesh size). Increased amounts of conjugated methacrylate groups corresponded with increased crosslink densities and decreased degradation rates and yet had an insignificant effect on human aortic endothelial cell cytocompatibility and proliferation. Rat subcutaneous implants of the GMHA hydrogels showed good biocompatibility, little inflammatory response, and similar levels of vascularization at the implant edge compared with those of fibrin positive controls. Therefore, these novel GMHA hydrogels are suitable for modification with adhesive peptide sequences (e.g., RGD) and use in a variety of wound-healing applications.

Voriconazole: a new triazole antifungal agent

Voriconazole is a second-generation azole antifungal agent that shows excellent in vitro activity against a wide variety of yeasts and molds. It can be given by either the intravenous or the oral route; the oral formulation has excellent bioavailability. The side effect profile of voriconazole is unique in that non-sight-threatening, transient visual disturbances occur in approximately 30% of patients given the drug. Rash (which can manifest as photosensitivity) and hepatitis also occur. The potential for drug-drug interactions is high and requires that careful attention be given to dosage regimens and monitoring of serum levels and effects of interacting drugs. Voriconazole has been approved for the treatment of invasive aspergillosis and refractory infections with Pseudallescheria/Scedosporium and Fusarium species, and it will likely become the drug of choice for treatment of serious infections with those filamentous fungi.

Bovine acidosis: implications on laminitis

Bovine lactic acidosis syndrome is associated with large increases of lactic acid in the rumen, which result from diets that are high in ruminally available carbohydrates, or forage that is low in effective fiber, or both. The syndrome involves two separate anatomical areas, the gastrointestinal tract and body fluids, and is related to the rate and extent of lactic acid production, utilization, and absorption. Clinical manifestations range from loss of appetite to death. Lactic acid accumulates in the rumen when the bacteria that synthesize lactic acid outnumber those that utilize lactic acid. The systemic impact of acidosis may have several physiological implications, including laminitis, a diffuse aseptic inflammation of the laminae (corium). Although a nutritional basis for the disease exists, etiology includes a multitude of interactive factors, such as metabolic and digestive disorders, postpartum stress, and localized trauma, which lead to the release of vasoactive substances that trigger mechanisms that cause degenerative changes in the foot. The severity of laminitis is related to the frequency, intensity, and duration of systemic acidotic insults on the mechanisms responsible for the release of vasoactive substance. The critical link between acidosis and laminitis appears to be associated with a persistent hypoperfusion, which results in ischemia in the digit. Management of acidosis is critical in preventing laminitis. High producing dairy herds attempting to maximize energy intake are continually confronted with subclinical acidosis and laminitis. Management of feeding and husbandry practices can be implemented to reduce incidence of disease.

Large and sustained induction of chemokines during impaired wound healing in the genetically diabetic mouse: prolonged persistence of neutrophils and macrophages during the late phase of repair

Chemokines are seen as the stimuli that largely control leukocyte migration. To assess whether the severely impaired process of cutaneous repair observed in genetically diabetic db/db mice is associated with a dysregulated infiltration of immune cells, we determined the expressional kinetics for the murine growth-regulated oncogene/melanoma growth stimulatory activity homolog macrophage inflammatory protein-2, and the macrophage chemoattractant protein-1, respectively. Wound repair in db/db mice was characterized by a sustained inflammatory response and a prolonged expression of macrophage inflammatory protein-2 and macrophage chemoattractant protein-1. Immuno-histochemistry revealed that keratinocytes at the wound margins expressed macrophage chemoattractant protein-1, whereas macrophage inflammatory protein-2 immunopositive signals were observed only in keratinocytes of hair follicles located adjacent to the wound site. Inactivation studies using neutralizing antibodies against macrophage chemoattractant protein-1 or macrophage inflammatory protein-2 indicated that sustained expression of these chemokines participated in a prolonged presence of neutrophils and macrophages at the wound site during diabetic repair. Furthermore, our data provide evidence that late infiltration (day 13 after injury) of neutrophils and macrophages into wounds in db/db mice was associated with a simultaneous downregulation of mRNA for receptors specific for macrophage inflammatory protein-2 and macrophage chemoattractant protein-1 in these animals.

CTLA-4 blockade with ipilimumab: long-term follow-up of 177 patients with metastatic melanoma

PURPOSE

Treatment with ipilimumab can cause objective tumor responses in patients with metastatic melanoma. We have treated 177 evaluable patients in three clinical trials and have long-term follow-up to evaluate the durability of responses.

EXPERIMENTAL DESIGN

Patients with metastatic melanoma were treated in three trials from 2002 to 2005. In protocol 1, 56 patients received ipilimumab with gp100 peptides. In protocol 2, 36 patients received ipilimumab with interleukin-2. In protocol 3, 85 patients received ipilimumab with intrapatient dose-escalation and were randomized to receive gp100 peptides. We have analyzed their long-term follow-up and survival data.

RESULTS

With median follow-up for protocols 1, 2, and 3 being 92, 84, and 71 months, median survival was 14, 16, and 13 months with 5-year survival rates being 13%, 25%, and 23%, respectively. Patients in protocol 2 had a 17% complete response (CR) rate, compared with 7% in protocol 1 and 6% in protocol 3. These CR rates are higher than previously reported for the same trials because some patients who eventually became complete responders had continual tumor regression months to years after therapy. All but one of the 15 complete responders are ongoing at 54+ to 99+ months.

CONCLUSIONS

This report provides the longest follow-up of patients with melanoma treated with ipilimumab and shows that ipilimumab can induce durable, potentially curative tumor regression in a small percentage of patients with metastatic melanoma. The combination of ipilimumab and interleukin-2 seems to have an increased CR rate, but this needs to be tested in a randomized trial.

Self-administered topical 5% imiquimod cream for external anogenital warts. HPV Study Group. Human PapillomaVirus

OBJECTIVE

To compare the safety and effectiveness of 5% and 1% imiquimod cream with vehicle cream in the treatment of external anogenital warts.

DESIGN

Randomized, double-blind, placebo-controlled comparison that evaluated patients for total clearance of their warts. Patients who experienced total clearance were evaluated for recurrence in a 12-week follow-up.

SETTING

Eleven ambulatory offices, including both private physician offices and referral medical centers.

PATIENTS

Three hundred eleven healthy men and women aged 18 years or older with 2 to 50 external anogenital warts were recruited from the practices of investigators, referring physicians, and advertisements. Eighty-two additional patients were screened but did not qualify. Four patients discontinued use of the medication because of adverse effects.

INTERVENTIONS

Five percent imiquimod (Aldara) cream, 1% imiquimod cream, or vehicle cream was applied to all external warts overnight 3 times each week for 16 weeks, or until all treated warts disappeared, whichever occurred first.

MAIN OUTCOME MEASUREMENTS

The number of patients experiencing the elimination of all baseline warts and the recurrence rate of these warts. In addition, the reduction in baseline wart area the duration of therapy required to eliminate warts, and the frequency and severity of adverse reactions were principal measurements.

RESULTS

In the intent-to-treat analysis, 54 (50%) of 109 patients who received 5% imiquimod cream, 21 (21%) of 102 of those who received 1% imiquimod cream, and 11 (11%) of 100 patients treated with vehicle cream experienced eradication of all treated baseline warts. The difference between the effectiveness of 5% imiquimod cream and the vehicle cream was statistically significant (P < .001). Of those patients whose warts cleared during therapy, 13% of patients who received 5% imiquimod experienced a recurrence of at least 1 wart. Recurrences occurred in none of the patients who used 1% imiquimod cream and in 10% of patients who used the vehicle cream. Local erythema was the most common adverse reaction, but the majority of patients in each group experienced no or only mild local inflammatory reactions. There were no differences in incidences of flulike symptoms among treatment groups.

CONCLUSIONS

Five percent imiquimod cream is an effective and safe self-administered therapy for external anogenital warts when applied 3 times a week overnight for up to 16 weeks. The recurrence rate is low.

Phase 1 Trials of rVSV Ebola Vaccine in Africa and Europe

BACKGROUND

The replication-competent recombinant vesicular stomatitis virus (rVSV)-based vaccine expressing a Zaire ebolavirus (ZEBOV) glycoprotein was selected for rapid safety and immunogenicity testing before its use in West Africa.

METHODS

We performed three open-label, dose-escalation phase 1 trials and one randomized, double-blind, controlled phase 1 trial to assess the safety, side-effect profile, and immunogenicity of rVSV-ZEBOV at various doses in 158 healthy adults in Europe and Africa. All participants were injected with doses of vaccine ranging from 300,000 to 50 million plaque-forming units (PFU) or placebo.

RESULTS

No serious vaccine-related adverse events were reported. Mild-to-moderate early-onset reactogenicity was frequent but transient (median, 1 day). Fever was observed in up to 30% of vaccinees. Vaccine viremia was detected within 3 days in 123 of the 130 participants (95%) receiving 3 million PFU or more; rVSV was not detected in saliva or urine. In the second week after injection, arthritis affecting one to four joints developed in 11 of 51 participants (22%) in Geneva, with pain lasting a median of 8 days (interquartile range, 4 to 87); 2 self-limited cases occurred in 60 participants (3%) in Hamburg, Germany, and Kilifi, Kenya. The virus was identified in one synovial-fluid aspirate and in skin vesicles of 2 other vaccinees, showing peripheral viral replication in the second week after immunization. ZEBOV-glycoprotein-specific antibody responses were detected in all the participants, with similar glycoprotein-binding antibody titers but significantly higher neutralizing antibody titers at higher doses. Glycoprotein-binding antibody titers were sustained through 180 days in all participants.

CONCLUSIONS

In these studies, rVSV-ZEBOV was reactogenic but immunogenic after a single dose and warrants further evaluation for safety and efficacy. (Funded by the Wellcome Trust and others; ClinicalTrials.gov numbers, NCT02283099, NCT02287480, and NCT02296983; Pan African Clinical Trials Registry number, PACTR201411000919191.).

Role of topical emollients and moisturizers in the treatment of dry skin barrier disorders

Emollients and moisturizing creams are used to break the dry skin cycle and to maintain the smoothness of the skin. The term 'moisturizer' is often used synonymously with emollient, but moisturizers often contain humectants in order to hydrate the stratum corneum. Dryness is frequently linked to an impaired barrier function observed, for example, in atopic skin, psoriasis, ichthyosis, and contact dermatitis. Dryness and skin barrier disorders are not a single entity, but are characterized by differences in chemistry and morphology in the epidermis. Large differences also exist between moisturizing creams. Moisturizers have multiple functions apart from moistening the skin. Similar to other actives, the efficacy is likely to depend on the dosage, where compliance is a great challenge faced in the management of skin diseases. Strong odor from ingredients and greasy compositions may be disagreeable to the patients. Furthermore, low pH and sensory reactions, from lactic acid and urea for example, may reduce patient acceptance. Once applied to the skin, the ingredients can stay on the surface, be absorbed into the skin, be metabolized, or disappear from the surface by evaporation, sloughing off, or by contact with other materials. In addition to substances considered as actives, e.g. fats and humectants, moisturizers contain substances conventionally considered as excipients (e.g. emulsifiers, antioxidants, preservatives). Recent findings indicate that actives and excipients may have more pronounced effects in the skin than previously considered. Some formulations may deteriorate the skin condition, whereas others improve the clinical appearance and skin barrier function. For example, emulsifiers may weaken the barrier. On the other hand, petrolatum has an immediate barrier-repairing effect in delipidized stratum corneum. Moreover, one ceramide-dominant lipid mixture improved atopic dermatitis and decreased transepidermal water loss (TEWL) in an open-label study in children. In double-blind studies moisturizers with urea have been shown to reduce TEWL in atopic and ichthyotic patients. Urea also makes normal and atopic skin less susceptible against irritation to sodium laurilsulfate. Treatments improving the barrier function may reduce the likelihood of further aggravation of the disease. In order to have optimum effect it is conceivable that moisturizers should be tailored with respect to the epidermal abnormality. New biochemical approaches and non-invasive instruments will increase our understanding of skin barrier disorders and facilitate optimum treatments. The chemistry and function of dry skin and moisturizers is a challenging subject for the practicing dermatologist, as well as for the chemist developing these agents in the pharmaceutical/cosmetic industry.

Infective dermatitis of Jamaican children: a marker for HTLV-I infection

In Jamaican children infective dermatitis is a chronic eczema associated with refractory nonvirulent Staphylococcus aureus or beta-haemolytic streptococcus infection of the skin and nasal vestibule. 14 children between the ages of 2 and 17 years with typical infective dermatitis, attending the dermatology clinic at the University Hospital of the West Indies in Jamaica, were tested for antibody to human T-lymphotropic virus type 1 (HTLV-1). All were seropositive, whereas 11 children of similar age with atopic eczema were all negative. In 2 of 2 cases of infective dermatitis, the biological mother was HTLV-1 seropositive. None of the 14 patients showed signs of adult T-cell leukaemia/lymphoma, though experience with previous cases of infective dermatitis indicates the possibility of such progression.

Age-related alterations in the inflammatory response to dermal injury

Previous studies have documented that the ability to heal wounds declines with age. Although many factors contribute to this age-associated deficit, one variable that has not been carefully examined is leukocyte recruitment and function in wounds. This investigation compares the inflammatory response in excisional wounds of young (age 8 wk) and aged (age 22 mo) mice. In the early inflammatory response, neutrophil content of wounds was similar for both aged and young mice. In contrast, macrophage levels were 56% higher in aged versus young mice (81 +/- 20 vs 52 +/- 13 cells per mm2). In the later inflammatory response, wounds of aged mice exhibited a delay in T cell infiltration, with maximum T cell levels at day 10 in aged mice versus day 7 in young mice. Despite this delay, the eventual peak concentration of T cells was 23% higher in the wounds of aged mice (152 +/- 11 cells per mm2 vs 124 +/- 21cells per mm2). The observed alterations in inflammatory cell content suggested that chemokine production might be altered with age. An elevation of monocyte chemoattractant protein (MCP-1) levels was observed in wounds of aged mice. RNase protection studies, however, revealed that the production of most chemokines, including MIP-2, MIP-1alpha, MIP-1beta, and eotaxin, tended to decline with age. Because optimal wound healing requires both appropriate macrophage infiltration and phagocytic activity, phagocytosis was examined. Compared to young mice, wound macrophages from aged mice exhibited a 37%-43% reduction in phagocytic capacity. Taken together, the data demonstrate age-related shifts in both macrophage and T cell infiltration into wounds, alterations in chemokine content, and a concurrent decline in wound macrophage phagocytic function. These alterations may contribute to the delayed repair response of aging.

Primary human T-lymphotropic virus type III infection

Primary infection with the human T-lymphotropic virus type III (HTLV-III) was documented in three patients by virus isolation during acute illness and concurrent or subsequent HTLV-III seroconversion. All patients had fevers, rigors, arthralgias, and myalgias. Additional symptoms included truncal maculopapular rash, urticaria, abdominal cramps, and diarrhea. Lymphocytic meningitis accompanied the febrile illness in two patients. The estimated incubation period was 4 to 6 weeks, and the symptoms lasted 2 to 3 weeks. Seroconversion occurred 8 to 12 weeks after presumed exposure and was manifested by a characteristic antibody response pattern. Physicians should consider the possibility of primary HTLV-III infection when evaluating patients who belong to one of the risk groups for the acquired immunodeficiency syndrome and who have prolonged febrile illnesses.

Corticotropin-releasing hormone induces skin mast cell degranulation and increased vascular permeability, a possible explanation for its proinflammatory effects

Mast cells are involved in atopic disorders, often exacerbated by stress, and are located perivascularly close to sympathetic and sensory nerve endings. Mast cells are activated by electrical nerve stimulation and millimolar concentrations of neuropeptides, such as substance P (SP). Moreover, acute psychological stress induces CRH-dependent mast cell degranulation. Intradermal administration of rat/human CRH (0.1-10 microM) in the rat induced mast cell degranulation and increased capillary permeability in a dose-dependent fashion. The effect of CRH on Evans blue extravasation was stronger than equimolar concentrations of the mast cell secretagogue compound 48/80 or SP. The free acid analog of CRH, which does not interact with its receptors (CRHR), had no biological activity. Moreover, systemic administration of antalarmin, a nonpeptide CRHR1 antagonist, prevented vascular permeability only by CRH and not by compound 48/80 or SP. CRHR1 was also identified in cultured leukemic human mast cells using RT-PCR. The stimulatory effect of CRH, like that of compound 48/80 on skin vasodilation, could not be elicited in the mast cell deficient W/Wv mice but was present in their +/+ controls, as well as in C57BL/6J mice; histamine could still induce vasodilation in the W/Wv mice. Treatment of rats neonatally with capsaicin had no effect on either Evans blue extravasation or mast cell degranulation, indicating that the effect of exogenous CRH in the skin was not secondary to or dependent on the release of neuropeptides from sensory nerve endings. The effect of CRH on Evans blue extravasation and mast cell degranulation was inhibited by the mast cell stabilizer disodium cromoglycate (cromolyn), but not by the antisecretory molecule somatostatin. To investigate which vasodilatory molecules might be involved in the increase in vascular permeability, the CRH injection site was pretreated with the H1-receptor antagonist diphenhydramine, which largely inhibited the CRH effect, suggesting that histamine was involved in the CRH-induced vasodilation. The possibility that nitric oxide might also be involved was tested using pretreatment with a nitric oxide synthase inhibitor that, however, increased the effect of CRH. These findings indicate that CRH activates skin mast cells at least via a CRHR1-dependent mechanism leading to vasodilation and increased vascular permeability. The present results have implications for the pathophysiology and possible therapy of skin disorders, such as atopic dermatitis, eczema, psoriasis, and urticaria, which are exacerbated or precipitated by stress.

p120-catenin mediates inflammatory responses in the skin

Although p120-catenin regulates adherens junction (AJ) stability in cultured cells, genetic studies in lower eukaryotes have not revealed a role for this protein in vivo. Using conditional targeting in mice, we show that p120 null neonatal epidermis exhibits reduced intercellular AJ components but no overt disruption in barrier function or intercellular adhesion. As the mice age, however, they display epidermal hyperplasia and chronic inflammation, typified by hair degeneration and loss of body fat. Using skin engraftments and anti-inflammatory drugs, we show that these features are not attributable to reductions in junctional cadherins and catenins, but rather NFkB activation. Both in vivo and in vitro, p120 null epidermal cells activate nuclear NFkB, triggering a cascade of proinflammatory NFkB targets. Although the underlying mechanism is likely complex, we show that p120 affects NFkB activation and immune homeostasis in part through regulation of Rho GTPases. These findings provide important new insights into p120 function.

Different patterns of hyperalgesia induced by experimental inflammation in human skin

Different types of hyperalgesia were studied after experimental induction of inflammation in small skin areas of healthy volunteers either by topical application of capsaicin solution (1% in 70% ethanol) or by briefly freezing a skin area of similar size to -28 degrees C. Sensory tests were performed 30 min after capsaicin application and 22 h after freeze lesions. Heat pain thresholds were lowered after both treatments, probably due to nociceptor sensitization. Hyperalgesia to four types of mechanical stimulation was studied. (i) Hyperalgesia to punctate stimuli was encountered at the skin site directly affected by the noxious chemical or freeze stimulus (1 degree zone) and in the surrounding skin (2 degrees zone) in both models though the area of 2 degrees hyperalgesia to punctate stimuli after freezing was smaller than after capsaicin. (ii) Hyperalgesia to gently brushing the skin was prominent after capsaicin in 1 degree and 2 degrees zone, but almost absent after freezing. It was concluded that both hyperalgesia to punctate stimuli and brush-evoked pain are due to central nervous plasticity changes rather than nociceptor sensitization. As revealed by differential nerve blocks, brush-evoked pain is mediated by low threshold mechanosensitive A beta-fibres, whilst hyperalgesia to punctate stimuli can be elicited when only C-fibres conduct. In contrast to hyperalgesia to punctate stimuli it requires continuous background discharges in nociceptor units. (iii) Pressure hyperalgesia to tonic stimulation with a blunt probe was encountered in the 1 degree zone of both types of inflammation and is probably due to recruitment of sensitized nociceptor units. (iv) Impact hyperalgesia was studied by shooting small bullets against the skin at predetermined velocities. It was found in the 1 degree zone after freezing and absent in the capsaicin model. Differential nerve blocks revealed that it is probably mediated by sensitized C-fibres. In conclusion, different types of inflammatory changes may result in characteristic different patterns of hyperalgesia.

Pellagra: dermatitis, dementia, and diarrhea

Pellagra defines systemic disease as resulting from a marked cellular deficiency of niacin. It is characterized by 4 "D's": diarrhea, dermatitis, dementia, and death. Diagnosis of pellagra is difficult in the absence of the skin lesions, and is often facilitated by the presence of characteristic ones. The dermatitis begins as an erythema. Acute pellagra resembles sunburn in its first stages, but tanning occurs more slowly than typically in sunburn. Exacerbation follows re-exposure to sunlight. In this work we review the findings of this once mysterious disorder, one that still challenges clinicians world-wide.

A syndrome of acute zinc deficiency during total parenteral alimentation in man

Changes in the plasma and urine levels of the trace metal zinc have been followed in a series of 37 adult patients totally supported by intravenous alimentation. Copper has also been determined in more recent cases. In such a seriously ill group, although urinary zinc loss may be very high at the height of catabolism, severe plasma depletion does not occur unless there is a subsequent phase of sustained anabolism and weight gain. In four patients plasma zinc fell to very low levels during this phase and three of this group developed a syndrome characterized by diarrhea, mental depression, para-nasal, oral and peri-oral dermatitis, and alopecia. The response to oral or intravenous zinc therapy is striking, except for hair regrowth which is delayed but eventually complete. The syndrome we have recognized in adult man has not been previously described. It resembles however the parakeratosis of zinc deficient swine and it is also very similar to Acrodermatitis enteropathica, a genetically determined disorder of infants very recently linked to zinc deficiency. Zinc is clearly essential to human metabolism and it should be included in all parenteral alimentation regimes particularly during the period of rapid, sustained, weight gain.

Inflammatory manifestations of experimental lymphatic insufficiency

BACKGROUND

Sustained lymph stagnation engenders a pathological response that is complex and not well characterized. Tissue inflammation in lymphedema may reflect either an active or passive consequence of impaired immune traffic.

METHODS AND FINDINGS

We studied an experimental model of acute post-surgical lymphedema in the tails of female hairless, immunocompetent SKH-1 mice. We performed in vivo imaging of impaired immune traffic in experimental, murine acquired lymphatic insufficiency. We demonstrated impaired mobilization of immunocompetent cells from the lymphedematous region. These findings correlated with histopathological alterations and large-scale transcriptional profiling results. We found intense inflammatory changes in the dermis and the subdermis. The molecular pattern in the RNA extracted from the whole tissue was dominated by the upregulation of genes related to acute inflammation, immune response, complement activation, wound healing, fibrosis, and oxidative stress response.

CONCLUSIONS

We have characterized a mouse model of acute, acquired lymphedema using in vivo functional imaging and histopathological correlation. The model closely simulates the volume response, histopathology, and lymphoscintigraphic characteristics of human acquired lymphedema, and the response is accompanied by an increase in the number and size of microlymphatic structures in the lymphedematous cutaneous tissues. Molecular characterization through clustering of genes with known functions provides insights into processes and signaling pathways that compose the acute tissue response to lymph stagnation. Further study of genes identified through this effort will continue to elucidate the molecular mechanisms and lead to potential therapeutic strategies for lymphatic vascular insufficiency.

TNF-alpha and IL-8 are upregulated in the epidermis of normal human skin after UVB exposure: correlation with neutrophil accumulation and E-selectin expression

The in vivo response to ultraviolet B (UVB) radiation in skin is characterized by the accumulation of both mononuclear and polymorphonuclear cells within the dermis and an induction of vascular endothelial adhesion molecules. Epidermal production of cytokines (IL-8 and TNF-alpha) has been strongly implicated in the development of UVB-induced inflammation. In the current study, we examined the time course of IL-8 and TNF-alpha mRNA and protein expression in the epidermis over a 24-h period after in vivo UVB irradiation. Also, the induction of adhesion molecule expression and the accumulation of neutrophils within the dermis were followed. We found constitutive expression of both cytokines (mRNA and protein) in the epidermis of unirradiated skin. IL-8 was rapidly upregulated after irradiation and mRNA and protein increased at 4 h, reaching a maximum between 8 and 24 h. TNF-alpha mRNA and protein was minimally increased by 8 h after UVB irradiation and reached a maximum by 24 h. No significant alteration in ICAM-1 or VCAM-1 expression was observed. E-selectin expression, which was absent from control samples, was increased from 4 h onward and also reached a maximum at 24 h, coinciding with peak neutrophil accumulation. A strong correlation (r = 0.96) was found between number of E-selectin-positive vessels and numbers of infiltrating neutrophils at this time. Moreover, because E-selectin expression was increased before any apparent increase in TNF-alpha protein (4 h), TNF-alpha does not appear to be involved in the early induction of the adhesion molecule, but cytokines such as TNF-alpha and IL-8 may act subsequently to augment the inflammatory response.

Incidence of metal sensitivity in patients with total joint replacements

Sensitivity to chromium, cobalt, nickel, molybdenum, vanadium, and titanium was studied by patch tests in 50 patients who had received total joint replacements. Nineteen (38%) were sensitive to one or more of the metals. In 23 patients non-traumatic failure of the prosthesis had occurred, and 15 of these patients were sensitive to metal. Out of 27 patients with no evidence of prosthesis loosening, four were sensitive to nickel and cobalt or nickel only. Dermatological reactions occurred in 13 patients after surgery; in only eight, however, was there evidence of metal sensitivity. These findings indicate that metal-on-metal total joint replacements may sensitise the patient to metals contained in the prosthesis. Although there is a high incidence of prosthesis failure among metal-sensitive patients it remains uncertain whether the loosening causes the sensitisation or vice versa.

Active or passive exposure to tobacco smoking and allergic rhinitis, allergic dermatitis, and food allergy in adults and children: a systematic review and meta-analysis

BACKGROUND

Allergic rhinitis, allergic dermatitis, and food allergy are extremely common diseases, especially among children, and are frequently associated to each other and to asthma. Smoking is a potential risk factor for these conditions, but so far, results from individual studies have been conflicting. The objective of this study was to examine the evidence for an association between active smoking (AS) or passive exposure to secondhand smoke and allergic conditions.

METHODS AND FINDINGS

We retrieved studies published in any language up to June 30th, 2013 by systematically searching Medline, Embase, the five regional bibliographic databases of the World Health Organization, and ISI-Proceedings databases, by manually examining the references of the original articles and reviews retrieved, and by establishing personal contact with clinical researchers. We included cohort, case-control, and cross-sectional studies reporting odds ratio (OR) or relative risk (RR) estimates and confidence intervals of smoking and allergic conditions, first among the general population and then among children. We retrieved 97 studies on allergic rhinitis, 91 on allergic dermatitis, and eight on food allergy published in 139 different articles. When all studies were analyzed together (showing random effects model results and pooled ORs expressed as RR), allergic rhinitis was not associated with active smoking (pooled RR, 1.02 [95% CI 0.92-1.15]), but was associated with passive smoking (pooled RR 1.10 [95% CI 1.06-1.15]). Allergic dermatitis was associated with both active (pooled RR, 1.21 [95% CI 1.14-1.29]) and passive smoking (pooled RR, 1.07 [95% CI 1.03-1.12]). In children and adolescent, allergic rhinitis was associated with active (pooled RR, 1.40 (95% CI 1.24-1.59) and passive smoking (pooled RR, 1.09 [95% CI 1.04-1.14]). Allergic dermatitis was associated with active (pooled RR, 1.36 [95% CI 1.17-1.46]) and passive smoking (pooled RR, 1.06 [95% CI 1.01-1.11]). Food allergy was associated with SHS (1.43 [1.12-1.83]) when cohort studies only were examined, but not when all studies were combined. The findings are limited by the potential for confounding and bias given that most of the individual studies used a cross-sectional design. Furthermore, the studies showed a high degree of heterogeneity and the exposure and outcome measures were assessed by self-report, which may increase the potential for misclassification.

CONCLUSIONS

We observed very modest associations between smoking and some allergic diseases among adults. Among children and adolescents, both active and passive exposure to SHS were associated with a modest increased risk for allergic diseases, and passive smoking was associated with an increased risk for food allergy. Additional studies with detailed measurement of exposure and better case definition are needed to further explore the role of smoking in allergic diseases.