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We have previously shown that healthy older adults exhibit reduced cutaneous immune responses during a varicella zoster virus (VZV) antigen challenge that correlated with a nonspecific inflammatory response to the injection itself. Here we found that needle damage during intradermal injections in older adults led to an increase in the number of cutaneous senescent fibroblasts expressing CCL2, resulting in the local recruitment of inflammatory monocytes. These infiltrating monocytes secreted prostaglandin E2, which inhibited resident memory T cell activation and proliferation. Pretreatment of older participants with a p38 mitogen-activated protein kinase inhibitor in vivo decreased CCL2 expression and inhibited monocyte recruitment and secretion of prostaglandin E2. This coincided with an increased response to VZV antigen challenge in the skin. Our results point to a series of molecular and cellular mechanisms that link cellular senescence, tissue damage, excessive inflammation and reduced immune responsiveness in human skin and demonstrate that tissue-specific immunity can be restored in older adults by short-term inhibition of inflammatory responses. The authors show that cutaneous immunity is attenuated during aging due to the recruitment, by senescent fibroblasts, of inflammatory monocytes, which in turn inhibit resident memory T cell activation. Inhibition of p38 MAPK signaling blocks the recruitment and function of these monocytes and restores immunity.

Pyoderma gangrenosum (PG) is a reactive non-infectious inflammatory dermatosis falling under the spectrum of the neutrophilic dermatoses. There are several subtypes, with ‘classical PG’ as the most common form in approximately 85% cases. This presents as an extremely painful erythematous lesion which rapidly progresses to a blistered or necrotic ulcer. There is often a ragged undermined edge with a violaceous/erythematous border. The lower legs are most frequently affected although PG can present at any body site. Other subtypes include bullous, vegetative, pustular, peristomal and superficial granulomatous variants. The differential diagnosis includes all other causes of cutaneous ulceration as there are no definitive laboratory or histopathological criteria for PG. Underlying systemic conditions are found in up to 50% of cases and thus clinicians should investigate thoroughly for such conditions once a diagnosis of PG has been made. Treatment of PG remains largely anecdotal, with no national or international guidelines, and is selected according to severity and rate of progression. Despite being a well-recognised condition, there is often a failure to make an early diagnosis of PG. This diagnosis should be actively considered when assessing ulcers, as prompt treatment may avoid the complications of prolonged systemic therapy, delayed wound healing and scarring.

Background The multi-morbid burden and use of systemic immunosuppressants in people with psoriasis may confer greater risk of adverse COVID-19 outcomes but data are limited. Objective Characterize the course of COVID-19 in psoriasis and identify factors associated with hospitalization. Methods Clinicians reported psoriasis patients with confirmed/suspected COVID-19 via an international registry, PsoProtect. Multiple logistic regression assessed the association between clinical/demographic characteristics and hospitalization. A separate patient-facing registry characterized risk-mitigating behaviours. Results Of 374 clinician-reported patients from 25 countries, 71% were receiving a biologic, 18% a non-biologic and 10% no systemic treatment for psoriasis. 348 (93%) fully recovered from COVID-19, 77 (21%) were hospitalized and nine (2%) died. Increased hospitalization risk was associated with older age (multivariable-adjusted OR 1.59 per 10 years, 95% CI 1.19-2.13), male sex (OR 2.51, 95% CI 1.23-5.12), non-white ethnicity (OR 3.15, 95% CI 1.24-8.03) and comorbid chronic lung disease (OR 3.87, 95% CI 1.52-9.83). Hospitalization was more frequent in patients using non-biologic systemic therapy than biologics (OR 2.84, 95% CI 1.31-6.18). No significant differences were found between biologic classes. Independent patient-reported data (n=1,626 across 48 countries) suggested lower levels of social isolation in individuals receiving non-biologic systemic therapy compared to biologics (OR 0.68, 95% CI 0.50-0.94). Conclusion In this international moderate-severe psoriasis case series, biologics use was associated with lower risk of COVID-19-related hospitalization than non-biologic systemic therapies, however further investigation is warranted due to potential selection bias and unmeasured confounding. Established risk factors (being older, male, non-white ethnicity, comorbidities) were associated with higher hospitalization rates. Clinical Implications We identify risk factors for COVID-19-related hospitalization in psoriasis patients, including older age, male sex, non-white ethnicity and comorbidities. Use of biologics was associated with lower hospitalization risk than non-biologic systemic therapies., Capsule summary: In this global registry-based study, risk factors for COVID-19-related hospitalization in psoriasis patients were older age, male sex, non-white ethnicity and comorbidities. Use of biologics was associated with lower hospitalization risk than non-biologic systemic treatment.

Summary Introduction Ageing is associated with increased number of infections, decreased vaccine efficacy and increased systemic inflammation termed inflammageing. These changes are reflected by reduced recall responses to varicella zoster virus (VZV) challenge in the skin of older adults. Vitamin D deficiency is more common in the old and has been associated with frailty and increased inflammation. In addition, vitamin D increases immunoregulatory mechanisms and therefore has the potential to inhibit inflammageing. Objectives We investigated the use of vitamin D3 replacement to enhance cutaneous antigen-specific immunity in older adults (≥65 years). Methods Vitamin D insufficient older adults (n = 18) were administered 6400IU of vitamin D3/day orally for 14 weeks. Antigen-specific immunity to VZV was assessed by clinical score assessment of the injection site and transcriptional analysis of skin biopsies collected from challenged injection sites pre- and post-vitamin D3 replacement. Results We showed that older adults had reduced VZV-specific cutaneous immune response and increased non-specific inflammation as compared to young. Increased non-specific inflammation observed in the skin of older adults negatively correlated with vitamin D sufficiency. We showed that vitamin D3 supplementation significantly increased the response to cutaneous VZV antigen challenge in older adults. This enhancement was associated with a reduction in inflammatory monocyte infiltration with a concomitant enhancement of T cell recruitment to the site of antigen challenge in the skin. Conclusion Vitamin D3 replacement can boost antigen-specific immunity in older adults with sub-optimal vitamin D status.

Ageing results in a decline in immune function. We showed previously that healthy older humans (>65 years old) have reduced antigen-specific cutaneous immunity to varicella zoster virus (VZV) antigen challenge. This was associated with p38 MAP kinase driven inflammation that was induced by mild tissue injury caused by the injection of the antigen itself. Here we show that non-specific injury induced by injection of air or saline into the skin of older adults recruits CCR2+CD14+monocytes by CCL2 produced by senescent fibroblasts. These monocytes reduced TRMproliferation via secretion of prostaglandin E2 (PGE2). Pre-treatment with a p38-MAPK inhibitor (Losmapimod) in older adultsin vivosignificantly decreased CCL2 expression, recruitment of monocyte into the skin, COX2 expression and PGE2production. This enhanced the VZV response in the skin. Therefore, local inflammation arising from interaction between senescent cells and monocytes leads to immune decline in the skin during ageing, a process that can be reversed.SummaryInflammation resulting from tissue injury blocks antigen-specific cutaneous immunity during ageing. Monocytes recruited to the skin inhibit TRMfunction through COX2-derived prostaglandin E2production. Blocking inflammation and resulting prostaglandin E2production with a p38-MAP kinase inhibitor significantly enhances cutaneous antigen-specific responses.

Human-virus-specific CD8+ T cells that are found during primary infection have been studied almost exclusively in the peripheral blood, and it is unclear whether these cells are regulated in the same way as those in secondary lymphoid tissue. We investigated, therefore, the control of apoptosis and telomere erosion of Epstein-Barr virus (EBV)-specific CD8+ T cells found in the blood and tonsils of the same patients during acute infectious mononucleosis (AIM). Although the clonal composition of CD8+ T cells as determined by heteroduplex analysis was similar in both compartments, there was greater CD28 expression in the tonsil population, indicating that they were less differentiated. EBV-specific CD8+ T cells in both tissue types were extremely susceptible to apoptosis related to low Bcl-2 expression and were dependent on exogenous cytokines such as interleukin-2 (IL-2), IL-15, and interferon-alpha/beta (IFN-alpha/beta) for survival. In both compartments, however, these cells maintained their telomere lengths through telomerase induction. Thus, apoptosis-prone EBV-specific CD8+ T cells found during acute infection have to be rescued from death to persist as a memory population. However, signals that induce telomerase ensure that the rescued cells retain their replicative capacity. Significantly, these processes operate identically in cells found in blood and secondary lymphoid tissue.

The extent of human memory T cell proliferation, differentiation, and telomere erosion that occurs after a single episode of immune challenge in vivo is unclear. To investigate this, we injected tuberculin purified protein derivative (PPD) into the skin of immune individuals and isolated responsive T cells from the site of antigenic challenge at different times. PPD-specific CD4+ T cells proliferated and differentiated extensively in the skin during this secondary response. Furthermore, significant telomere erosion occurred in specific T cells that respond in the skin, but not in those that are found in the blood from the same individuals. Tissue fluid obtained from the site of PPD challenge in the skin inhibited the induction of the enzyme telomerase in T cells in vitro. Antibody inhibition studies indicated that type I interferon (IFN), which was identified at high levels in the tissue fluid and by immunohistology, was responsible in part for the telomerase inhibition. Furthermore, the addition of IFN-α to PPD-stimulated CD4+ T cells directly inhibited telomerase activity in vitro. Therefore, these results suggest that the rate of telomere erosion in proliferating, antigen-specific CD4+ T cells may be accelerated by type I IFN during a secondary response in vivo.

Although human naturally occurring regulatory T cells (Tregs) may express either CD45RA or CD45RO, we find in agreement with previous reports that the (∼80%) majority of natural Tregs in adults are CD45RO+. The proportion of CD45RA+ Tregs decreases, whereas CD45RO+ Tregs increase significantly with age. Nevertheless, a small proportion of CD45RA+ Tregs are found even in old (>80 y) adults and a proportion of these express CD31, a marker for recent thymic emigrants. We found that CD45RO+ Tregs were highly proliferative compared with their CD45RA+ counterparts. This was due in part to the conversion of CD45RA Tregs to CD45RO expression after activation. Another difference between these two Treg populations was their preferential migration to different tissues in vivo. Whereas CD45RA+ Tregs were preferentially located in the bone marrow, associated with increased CXCR4 expression, CD45RO+ Tregs were preferentially located in the skin, and this was associated with their increased expression of CLA and CCR4. Our studies therefore show that proliferation features strongly in maintenance of the adult Treg pool in humans and that the thymus may make a minor contribution to the maintenance of the peripheral pool of these cells, even in older adults. Furthermore, the different tissue compartmentalization of these cells suggests that different Treg niches exist in vivo, which may have important roles for their maturation and function.

Immunity declines during aging, however the mechanisms involved in this decline are not known. In this study, we show that cutaneous delayed type hypersensitivity (DTH) responses to recall antigens are significantly decreased in older individuals. However, this is not related to CC chemokine receptor 4, cutaneous lymphocyte-associated antigen, or CD11a expression by CD4+ T cells or their physical capacity for migration. Instead, there is defective activation of dermal blood vessels in older subject that results from decreased TNF-α secretion by macrophages. This prevents memory T cell entry into the skin after antigen challenge. However, isolated cutaneous macrophages from these subjects can be induced to secrete TNF-α after stimulation with Toll-like receptor (TLR) 1/2 or TLR 4 ligands in vitro, indicating that the defect is reversible. The decreased conditioning of tissue microenvironments by macrophage-derived cytokines may therefore lead to defective immunosurveillance by memory T cells. This may be a predisposing factor for the development of malignancy and infection in the skin during aging.

Atopic dermatitis often requires long-term treatment. This European, multicentre, non-comparative, 24-month, follow-up study investigated the efficacy and safety of 0.1% tacrolimus ointment applied to adults with atopic dermatitis. Patients (n=672) applied a thin layer of 0.1% tacrolimus ointment twice daily for 3 weeks to all affected body areas. After 3 weeks, ointment was applied once daily. Clinical improvement became apparent after 2 weeks of treatment and 65.5% of patients had a rating of clearance, excellent or marked improvement by month 3. Skin burning (31.7%) was the most common causally-related adverse event, followed by pruritus (11.3%) folliculitis (6.4%), alcohol intolerance (5.7%), herpes simplex (5.7%), skin infection (4.6%), skin erythema (3.3%) and hyperaesthesia (2.4%). The most commonly reported infections were flu syndrome (12.9%), skin infection (9.8%), folliculitis (7.4%) and herpes simplex (7.0%). Long-term treatment up to 24 months with 0.1% tacrolimus ointment is safe and efficacious in adults with atopic dermatitis.

Contains fulltext : 53193.pdf (Publisher’s version ) (Open Access) Tacrolimus ointment is a topical calcineurin inhibitor for the treatment of atopic dermatitis. The primary objective of this open-label study was to assess the long-term safety of tacrolimus ointment. The primary end-point was the incidence of adverse events. Secondary end-points included the Eczema Area and Severity Index and a modified version of this index. A total of 466 children with atopic dermatitis, aged 2-15 years, applied 0.03% or 0.1% tacrolimus ointment twice daily for up to 29.5 months. Skin burning and pruritus were the most common application site events; their prevalence decreased over time. There was no increase in viral infections or other adverse events over time. Laboratory profiles were consistent with those reported in atopic populations. Substantial improvement in all efficacy end-points was observed by week 2 and maintained throughout the study. Long-term treatment with tacrolimus ointment is safe and effective in these patients with atopic dermatitis.

After acute infection Epstein-Barr virus (EBV)-specific memory CD8+ T cells exit cell cycle, and a proportion of these antigen-experienced cells re-express CD45RA (CD45 which predominantly express exon A). However, the signals involved are not known. We investigated the roles of interleukin 15 (IL-15) and interferon-alpha/beta (IFN-I) in these processes, since these mediators have a crucial but undefined role in the maintenance of CD8+ T-cell memory. We show that IFN-I (but not IL-15) allows activated EBV-specific CD8+ T cells to leave cell cycle without entering apoptosis. This was associated with up-regulation of the cyclin inhibitor p27, but not of CD45RA. In contrast, IL-15 (but not IFN-I) induced "homeostatic" proliferation and CD45RA re-expression by these cells in vitro. Different signals, therefore, induce quiescence and CD45RA re-expression in activated EBV-specific CD8+ T cells. After T-cell receptor (TCR) activation freshly isolated CD45RA+ antigen-experienced CD8+ T cells show poor proliferative activity but are highly cytotoxic and secrete IFN-gamma efficiently. This suggests functional reprogramming toward effector function but away from proliferation. The induction of quiescence and the generation of proliferation-independent effector CD8+ T cells that re-express CD45RA may minimize the impact of replicative senescence in virus-specific populations that would otherwise occur during decades of persistent infection.

Reactivation of the varicella zoster virus (VZV) increases during aging. Although the effects of VZV reactivation are observed in the skin (shingles), the number and functional capacity of cutaneous VZV-specific T cells have not been investigated. The numbers of circulating IFN-γ-secreting VZV-specific CD4(+) T cells are significantly decreased in old subjects. However, other measures of VZV-specific CD4(+) T cells, including proliferative capacity to VZV antigen stimulation and identification of VZV-specific CD4(+) T cells with an major histocompatibility complex class II tetramer (epitope of IE-63 protein), were similar in both age groups. The majority of T cells in the skin of both age groups expressed CD69, a characteristic of skin-resident T cells. VZV-specific CD4(+) T cells were significantly increased in the skin compared with the blood in young and old subjects, and their function was similar in both age groups. In contrast, the number of Foxp3(+) regulatory T cells and expression of the inhibitory receptor programmed cell death -1 PD-1 on CD4(+) T cells were significantly increased in the skin of older humans. Therefore, VZV-specific CD4(+) T cells in the skin of older individuals are functionally competent. However, their activity may be restricted by multiple inhibitory influences in situ.

Anergic/suppressive CD4+CD25+ T cells exist in animal models but their presence has not yet been demonstrated in humans. We have identified and characterized a human CD4+CD25+ T cell subset, which constitutes 7–10 % of CD4+ T cells in peripheral blood and tonsil. These cells are a CD45RO+CD45RBlow highly differentiated primedT cell population that is anergic to stimulation. Depletion of this small subset from CD4+ T cells significantly enhances proliferation by threefold in the remaining CD4+CD25– T cells, while the addition of isolated CD4+CD25+ T cells to CD4+CD25– T cells significantly inhibits proliferative activity. Blocking experiments suggest that suppression is not mediated via IL-4, IL-10 or TGF-β and is cell-contact dependent. Isolated CD4+CD25+ T cells are susceptible to apoptosis that is associated with low Bcl-2 expression, but this death can be prevented by IL-2 or fibroblast-secreted IFN-β. However, the anergic/suppressive state of these cells is maintained after cytokine rescue. These human regulatory cells are therefore a naturally occurring, highly suppressive, apoptosis-prone population which are at a late stage of differentiation. Further studies into their role in normal and pathological situations in humans are clearly essential.

We investigated the relationship between varicella zoster virus (VZV)–specific memory CD4+ T cells and CD4+Foxp3+ regulatory T cells (Tregs) that accumulate after intradermal challenge with a VZV skin test Ag. VZV-specific CD4+ T cells were identified with a MHC class II tetramer or by intracellular staining for either IFN-γ or IL-2 after Ag rechallenge in vitro. VZV-specific T cells, mainly of a central memory (CD45RA−CD27+) phenotype, accumulate at the site of skin challenge compared with the blood of the same individuals. This resulted in part from local proliferation because >50% of tetramer defined Ag-specific CD4+ T cells in the skin expressed the cell cycle marker Ki67. CD4+Foxp3+ T cells had the characteristic phenotype of Tregs, namely CD25hiCD127loCD39hi in both unchallenged and VZV challenged skin and did not secrete IFN-γ or IL-2 after antigenic restimulation. The CD4+Foxp3+ T cells from unchallenged skin had suppressive activity, because their removal led to an increase in cytokine secretion after activation. After VZV Ag injection, Foxp3+CD25hiCD127loCD39hi T cells were also found within the VZV tetramer population. Their suppressive activity could not be directly assessed by CD25 depletion because activated T cells in the skin were also CD25+. Nevertheless, there was an inverse correlation between decreased VZV skin responses and proportion of CD4+Foxp3+ T cells present, indicating indirectly their inhibitory activity in vivo. These results suggest a linkage between the expansion of Ag-specific CD4+ T cells and CD4+ Tregs that may provide controlled responsiveness during Ag-specific stimulation in tissues.

cated that MBTPS2 is mainly expressed in the upper granular layer in normal skin, as previously shown (Aten et al., 2010); however, in OS skin, MBTPS2 was expressed throughout the epidermis (Figure 2c). There was no apparent difference in MBTPS2 localization in the skin of a KFSD patient with the p.N508S mutation (Aten et al., 2010). It is unclear why this is but it may be because of differences in processing of the mutants in the two diseases. In summary, we demonstrate a novel association between an MBTPS2 mutation and an X-linked form of OS. This expands the number of disorders linked to MBTPS2 mutations and reveals clinical heterogeneity associated with different MBTPS2 mutations. Written, informed consent was obtained from all family members or their legal guardians. This study was approved by the South East NHS Research Ethics Committee and was performed according to the Declaration of Helsinki Principles.

Basophils have been implicated as a source of histamine and pro-inflammatory eicosanoids in atopic dermatitis. However, mechanisms regulating basophil mediator release are not understood. An H3 receptor involved in the control of histamine synthesis and release has been identified in nervous tissue. In this study we have investigated 1) release of histamine, leukotriene C4, and prostaglandin D2 from anti-immunoglobulin E (IgE)-stimulated basophils of adults with atopic dermatitis and unaffected individuals and 2) specific H3 receptor-dependent basophil mediator release, using an H3 receptor agonist and antagonist. Basophil-rich leukocyte fractions were prepared by dextran sedimentation of venous blood from 19 patients with atopic dermatitis (five male, 14 female, mean age 30.6 years, range 19-59 years) and 15 unaffected individuals (five male, 10 female, mean age 27.6 years, range 19-50 years). Anti-IgE (0.78-78.0 micrograms/ml) stimulation of basophils induced a concentration-dependent release of histamine and leukotriene C4, but not prostaglandin D2. Histamine release was maximally induced by 7.8 micrograms/ml anti-IgE with no significant (Mann-Whitney U test) difference between atopic basophils (n = 17; 43.65 +/- 4.16% mean +/- SEM) and normal basophils (n = 13; 52.23 +/- 4.39%). LTC4 release was maximal from atopic basophils incubated with 2.6 micrograms/ml anti-IgE (n = 5; 0.99 +/- 0.29 pg/10(6) cells) and from normal basophils incubated with 0.78 microgram/ml anti-IgE (n = 5; 25.38 +/- 5.79 pg/10(6) cells). Anti-IgE-stimulated release of leukotriene C4 from atopic basophils was significantly less than from normal basophils at all concentrations (p0.05). Basophils were co-incubated with anti-IgE (2.6 and 7.8 micrograms/ml) and either the H3 receptor agonist, (R)alpha-methylhistamine (10(-8) and 10(-7) M), or the H3 receptor antagonist thioperamide (10(-6) and 10(-5) M). Neither drug modulated anti-IgE-induced release of histamine (atopics, n = 10; normals, n = 8). These results indicate 1) that basophils from adults with atopic dermatitis release the same amount of histamine as, but less leukotriene C4 than, basophils of unaffected adults and 2) that H3 receptors are not involved in anti-IgE release of histamine from basophils. These data do not support a role for increased basophil release of histamine as a mediator in the itch and erythema of atopic dermatitis in adults.

There is increasing evidence that exposure to organic allergens may induce or exacerbate lesional skin in patients with atopic dermatitis. In this study, patients with atopic dermatitis were patch tested to 11 common organic allergens and to control chambers containing 0.4% phenol and 50% glycerin in 0.9% saline. In biopsies from positive patch test reactions, patch test control skin, lesional eczematous and non-lesional skin from atopic individuals, and normal skin from non-atopic volunteers, the presence and distribution of macro- phages (RFD7+), dendritic cells (RFD1+), and Langerhans cells, and the expression of the low-affinity receptor for IgE (CD23) were investigated. In patch test reactions and lesional skin samples, inflammatory infiltrates of diffusely distributed macrophages (RFD7+), dendritic cells (RFD1+), T lymphocytes (RFTmix+), and Langerhans cells (CD1+) were seen, the latter being present in both the epidermis and the dermis. The numbers of Langerhans cells were reduced in the epidermis and increased in the dermis in patch test reactions and lesional skin compared to their controls. Double staining revealed a change in the distribution of CD23 antigen. In patch test control and non-lesional biopsies many macro- phages and only a few Langerhans cells within the dermal infiltrates expressed this antigen. In patch test reaction and lesional skin samples, however, the proportion of CD23+ dermal Langerhans cells had increased compared to macro- phages. Furthermore, in these latter samples an increased proportion of dermal CD1+ cells expressed the dendritic cell (RFD1+) marker. These results show that following antigen challenge there are marked similarities between the phenotype of the cellular infiltrate in patch test reaction and lesional skin biopsies, and also demonstrate a changing distribution of CD23 on antigen-presenting cells.

Naturally occurring CD4(+)CD25(hi)Foxp3(+) Tregs (nTregs) are highly proliferative in blood. However, the kinetics of their accumulation and proliferation during a localized antigen-specific T cell response is currently unknown. To explore this, we used a human experimental system whereby tuberculin purified protein derivative (PPD) was injected into the skin and the local T cell response analyzed over time. The numbers of both CD4(+)Foxp3(-) (memory) and CD4(+)Foxp3(+) (putative nTreg) T cells increased in parallel, with the 2 populations proliferating at the same relative rate. In contrast to CD4(+)Foxp3(-) T cell populations, skin CD4(+)Foxp3(+) T cells expressed typical Treg markers (i.e., they were CD25(hi), CD127(lo), CD27(+), and CD39(+)) and did not synthesize IL-2 or IFN-gamma after restimulation in vitro, indicating that they were not recently activated effector cells. To determine whether CD4(+)Foxp3(+) T cells in skin could be induced from memory CD4(+) T cells, we expanded skin-derived memory CD4(+) T cells in vitro and anergized them. These cells expressed high levels of CD25 and Foxp3 and suppressed the proliferation of skin-derived responder T cells to PPD challenge. Our data therefore demonstrate that memory and CD4(+) Treg populations are regulated in tandem during a secondary antigenic response. Furthermore, it is possible to isolate effector CD4(+) T cell populations from inflamed tissues and manipulate them to generate Tregs with the potential to suppress inflammatory responses.

Repeated antigenic encounter drives proliferation and differentiation of memory T cell pools. An important question is whether certain specific T cells may be driven eventually to exhaustion in elderly individuals since the human life expectancy is increasing. We found that CMV-specific CD4+ T cells were significantly expanded in healthy young and old carriers compared with purified protein derivative-, varicella zoster virus-, EBV-, and HSV-specific populations. These CMV-specific CD4+ T cells exhibited a late differentiated phenotype since they were largely CD27 and CD28 negative and had shorter telomeres. Interestingly, in elderly CMV-seropositive subjects, CD4+ T cells of different specificities were significantly more differentiated than the same cells in CMV-seronegative individuals. This suggested the involvement of bystander-secreted, differentiation-inducing factors during CMV infection. One candidate was IFN-α, which induced loss of costimulatory receptors and inhibited telomerase in activated CD4+ T cells and was secreted at high levels by CMV-stimulated plasmacytoid dendritic cells (PDC). The CMV-specific CD4+ T cells in elderly subjects had severely restricted replicative capacity. This is the first description of a human memory T cell population that is susceptible to being lost through end-stage differentiation due to the combined effects of lifelong virus reactivation in the presence of bystander differentiation-inducing factors.

Although atopic dermatitis generally responds to topical therapy, small numbers of patients have severe resistant disease despite second-line therapies. High-dose intravenous immunoglobulin has been suggested to be of benefit in a small number of reports. We have conducted an open, single-centre study of adjunctive high-dose intravenous immunoglobulin (Flebogamma 1 5%). Six patients received treatment at 2 g kg 21 month 21 for 6 cycles, with a 3-month follow-up period. Skin scores, lymphocyte phenotypes and intracellular cytokine analysis were performed. Four of six patients had major improvements in skin scores and the overall reduction was significant (p~0.035). CD4z T-cell numbers fell following highdose intravenous immunoglobulin infusions, recovering by the next cycle. T-cell CD69 expression decreased to 60% of baseline values. Reductions in the proinflammatory cytokines IFN-c and TNF-a were non-significant. Adjunctive high-dose intravenous immunoglobulin may be a useful therapeutic approach in adults with severe treatment-resistant atopic dermatitis, but it will require further assessment in randomized controlled trials to establish this. Key words: atopic dermatitis; intravenous immunoglobulin; intracellular cytokines.

We investigated the use of purinergic receptors as a new treatment modality for nonmelanoma skin cancers. Purinergic receptors, which bind adenosine 5'-tri-phosphate, are expressed on human cutaneous keratinocytes. Previous work in rat and human epidermis suggested functional roles for purinergic receptors in the regulation of proliferation, differentiation, and apoptosis. Immunohistochemical analysis of frozen sections in human basal cell carcinomas and squamous cell carcinomas for P2X5, P2X7, P2Y1, P2Y2, and P2Y4 receptors was performed, accompanied by detailed analysis of archive material of tumor subtypes in paraffin sections. Functional studies were performed using a human cutaneous squamous cell carcinoma cell line (A431), where purinergic receptor subtype agonists were applied to cells and changes in cell number were quantified via a colorimetric assay. Immunostaining in paraffin sections was essentially the same as that in frozen sections, although more detail of the subcellular composition was visible. P2X5 and P2Y2 receptors were heavily expressed in basal cell carcinomas and squamous cell carcinomas. P2X7 receptors were expressed in the necrotic center of nodular basal cell carcinomas and in apoptotic cells in superficial multifocal and infiltrative basal cell carcinomas, and squamous cell carcinomas. P2Y1 receptors were only expressed in the stroma surrounding tumors. P2Y4 receptors were found in basal cell carcinomas but not in squamous cell carcinomas. P2X5 receptors appear to be associated with differentiation. The P2X7 receptor agonist benzoylbenzoyl-adenosine 5'-triphosphate and high concentrations of adenosine 5'-triphosphate (1000-5000 microM) caused a significant reduction in A431 cell number (p0.001), whereas the P2Y2 receptor agonist uridine 5'-triphosphate caused a significant amount of proliferation (p0.001). We have demonstrated that non-melanoma skin cancers express functional purinergic receptors and that P2X7 receptor agonists significantly reduce cell numbers in vitro.

Background. Cutaneous malignant melanoma (CMM) is a recognized feature of the Lynch type II cancer-family syndrome and the Li-Fraumeni's syndrome. A significant contribution of these syndromes to the total burden of CMM would be reflected in an increased risk of nonmelanoma cancers in first degree relatives. Methods. Pedigrees were taken from 85 patients with CMM using a family history questionnaire. The relative risk of death from all cancers and individual cancers in first degree relatives was calculated. Results. Of the 85 questionnaires, those of 79 patients were completed and of adequate quality for analysis. The first degree relatives of CMM patients showed no increased risk of cancer death, the relative risk of cancer death being 1.0. Six patients (7.6%) had first degree relatives with CMM. One patient had a family history compatible with the dominant transmission of a predisposition to cancer. Conclusions. It is important to establish whether an increased cancer risk is present in relatives of patients with malignancies so that screening programs may be offered. This study provides little evidence to support seeing relatives for noncutaneous malignancies in the absence of a dominant family history of predisposition to cancers. The increased frequency of CMM in relatives suggests that relatives of CMM patients should be counseled on protection from the sun and examination of the skin for melanoma.

A 29 year old man was referred to the dermatology department by the accident and emergency department because of a “maculopapular rash.” He had a four day history of an upper respiratory tract infection. Within half an hour of ingesting an over-the-counter flu remedy he developed redness and itching of his skin and a burning sensation in his groins and axillae. An hour later he felt systemically unwell with a painful skin. He had a history of infantile eczema, did not take regular medications or recreational drugs, and had no known drug allergies. He reported previous use of cold and flu remedies without ill effect, had no history of recent travel, but admitted to a single episode of unprotected intercourse a month earlier with a female sex worker. On examination, he was diaphoretic with cool peripheries, had a temperature of 38°C, his pulse rate was 120 beats/min, and his blood pressure was 110/56 mm Hg. Confluent erythema covered his entire body, with petechiae and oedema of his lower legs (figs 1⇓ and 2⇓). There were no palpable epidermal changes, there was no mucosal involvement, and Nikolsky’s sign was negative. He had cervical, axillary, and inguinal lymphadenopathy. Systemic examination was otherwise unremarkable. Bloods tests showed leucocytosis with a neutrophilic shift, eosinophilia, and raised inflammatory markers (table 1⇓). View this table: Table 1 Our patient’s sequential blood results ### 1 What is the differential diagnosis of erythroderma in this patient? #### Short answer Toxic erythema, an adverse drug eruption, HIV seroconversion, secondary syphilis, pityriasis rubra pilaris, …

While memory T cells are maintained by continuous turnover, it is not clear how human regulatory CD4(+)CD45RO(+)CD25(hi) Foxp3(+) T lymphocyte populations persist throughout life. We therefore used deuterium labeling of cycling cells in vivo to determine whether these cells could be replenished by proliferation. We found that CD4(+)CD45RO(+)Foxp3(+)CD25(hi) T lymphocytes were highly proliferative, with a doubling time of 8 days, compared with memory CD4(+)CD45RO(+)Foxp3(-)CD25(-) (24 days) or naive CD4(+)CD45RA(+)Foxp3(-)CD25(-) populations (199 days). However, the regulatory population was susceptible to apoptosis and had critically short telomeres and low telomerase activity. It was therefore unlikely to be self regenerating. These data are consistent with continuous production from another population source. We found extremely close TCR clonal homology between regulatory and memory CD4(+) T cells. Furthermore, antigen-related expansions within certain TCR V beta families were associated with parallel numerical increases of CD4(+)CD45RO(+)CD25(hi)Foxp3(+) Tregs with the same V beta usage. It is therefore unlikely that all human CD4(+)CD25(+)Foxp3(+) Tregs are generated as a separate functional lineage in the thymus. Instead, our data suggest that a proportion of this regulatory population is generated from rapidly dividing, highly differentiated memory CD4(+) T cells; this has considerable implications for the therapeutic manipulation of these cells in vivo.

Anergic/suppressive CD4+CD25+ T cells have been proposed to play an important role in the maintenance of peripheral tolerance. Here we demonstrate that in humans these cells suppress proliferation to self antigens, but also to dietary and foreign antigens. The suppressive CD4+CD25+ T cells display a broad usage of the T cell receptor Vbeta repertoire,suggesting that they recognize a wide variety of antigens. They reside in the primed/memory CD4+CD45RO+CD45RB(low) subset and have short telomeres, indicating that these cells have the phenotype of highly differentiated CD4+ T cells that have experienced repeated episodes of antigen-specific stimulation in vivo. This suggests that anergic/suppressive CD4+CD25+ T cells may be generated in the periphery as a consequence of repeated antigenic encounter. This is supported by the observation that highly differentiated CD4+T cells can be induced to become anergic/suppressive when stimulated by antigen presented by non-professional antigen-presenting cells. We suggest that besides being generated in the thymus, CD4+CD25+ regulatory T cells may also be generated in the periphery. This would provide a mechanism for the generation of regulatory cells that induce tolerance to a wide array of antigens that may not be encountered in the thymus.

Objective To investigate the safety and efficacy of using 0.1% tacrolimus ointment for long-term treatment of atopic dermatitis. Design Open-label, noncomparative study with 6 to 12 months of follow-up. Settings Outpatient departments in 30 study centers in 11 European countries. Patients We enrolled 316 patients aged 18 years and older with moderate to severe atopic dermatitis, 200 for 6 months and 116 for 12 months; 77.5% of patients completed the study. Intervention Twice-daily application of 0.1% tacrolimus ointment on all affected skin. Visits were scheduled on day 1; after 1, 2, and 4 weeks of treatment; and monthly thereafter. Main Outcome Measures Safety assessments included monitoring of adverse events, clinical laboratory values, and tacrolimus blood concentrations. Efficacy end points included a combined score (modified Eczema Area and Severity Index) and an investigator's global assessment. Results Local irritation, adverse events such as burning sensation (47% of patients), pruritus (24% of patients), and erythema (12% of patients) were common but tended to occur only when initiating treatment. Laboratory values showed no marked changes over time. Systemic absorption was minimal, with the maximum tacrolimus blood concentration being less than 1 ng/mL in 76% of patients. All efficacy end points showed improvement. The mean (SD) modified Eczema Area and Severity Index score was 23.7 (12.6) at day 1, 13.5 (11.3) at week 1, 6.1 (9.2) at month 6, and 6.1 (8.1) at month 12. Marked or excellent improvement or clearance of disease was reported in 54%, 81%, and 86% of patients at week 1, month 6, and month 12, respectively. Conclusion Up to 1 year of tacrolimus ointment use was safe and effective in patients with atopic dermatitis.

A disturbance in endothelial cell (EC) function may be pathogenetic in the thrombotic tendency of patients with the lupus anticoagulant (LA). The ability of serum from normal subjects and patients with systemic lupus erythematosus (SLE), with and without the LA, to modulate the release of prostacyclin (PGI 2 ) and the expression of procoagulant activity by cultured human EC was investigated. Only the 10% and 20% serum concentrations from patients with SLE-LA produced a significantly greater inhibition of 6-keto-prostaglandin F 1α (6-keto-PGF 1α ) release (the stable metabolite of PGI 2 ) than control serum. However, when patients with SLE-LA having Raynaud's phenomenon were excluded from this group, there was then no significant difference between the effect of the patient and control serum. Serum from patients with SLE-LA caused a significant increase in EC procoagulant activity compared to healthy controls. The two-stage partial thromboplastin time expressed in seconds decreased from 66 (normal) to 34 (SLE - LA) and 31 (SLE + LA), but there was no significant difference between the patients with and without the LA. The significantly increased EC procoagulant activity induced by serum from patients with SLE ± LA may account for the observed increased incidence of thrombotic events in patients with SLE. Our data suggest that factors other than decreased prostacyclin release are responsible for the altered hemostasis observed in patients with SLE + LA.

Prostacyclin (PGI 2 ) and PGE 2 , the predominant cyclooxygenase products of endothelial cells are potent vasodilators. An inability to produce appropriate concentrations of these prostanoids may be a factor in the pathogenesis of the digital vasospasm experienced by patients with Raynaud's phenomenon (RP). The effect of sera from normal subjects, patients with primary RP, and patients with RP in association with systemic sclerosis (SS) on the production of PGI 2 and PGE 2 by cultured human endothelial cells was investigated. All sera produced a dose-dependent inhibition of 6-keto-PGF 1α , but both the 10% and 20% sera from patients with RP and SS produced a significantly greater inhibition than control sera. The mean production of 6-keto-PGF 1α expressed in ng/10 4 cells was 2.278 (normal), 1.9311 (RP), and 2.1824 (SS) after incubation with 1% serum for 24 h. This decreased to 1.3647, 0.5927, and 0.4171, respectively following incubation with 20% sera for 24 h. This represented a 44% (normal), 76% (RP), and 83% (SS) inhibition of 6-keto-PGF 1α , production compared with serum free media. Similar results were obtained after 1 h incubation experiments. There was a nonsignificant decrease in mean PGE 2 production following similar incubations with 1% and 20% sera for 24 h. These results suggest that factor(s) present in the sera of patients with RP may reduce the ability of endothelial cells to synthesize or release the vasodilator and antiaggregatory prostanoid PGI 2 .