Basal keratinocytes from uninvolved psoriatic skin exhibit accelerated spreading and focal adhesion kinase responsiveness to fibronectin.

We previously proposed that the keratinocyte hyperproliferative state in psoriatic skin results from a combination of T cell cytokine interaction with basal keratinocytes that exist in a primed state. We now provide evidence that basal keratinocytes from psoriatic uninvolved skin are in a preactivated state with regard to their interaction with fibronectin. Freshly isolated basal keratinocytes (K(1)/K(10)(-)) from non-lesional psoriatic skin demonstrated a significantly higher percentage of spreading cells 1 h after plating on fibronectin-coated plates than keratinocytes isolated from normal skin (p =0.0002). No differences were observed on collagen-laminin-coated plates, however. The keratinocyte spreading on fibronectin-coated plates involved alpha 5 beta 1 and alpha V beta 1 integrins. To address the potential signaling cascades that may respond to integrin changes in psoriatic keratinocytes, focal adhesion kinase changes were assessed. The percentage of keratinocytes from psoriatic uninvolved skin that exhibit positive focal adhesion kinase staining was significantly greater than the percentage from healthy volunteers after 1 h incubation on fibronectin (p =0.006). Additionally, focal adhesion kinase isolated from uninvolved psoriatic keratinocytes had a greater degree of tyrosine phosphorylation. Thus, the proliferative effect of fibronectin in combination with T cell lymphokines on psoriatic uninvolved basal keratinocyte progenitors may be due to abnormal in vivo integrin-driven focal adhesion kinase activity and downstream signaling.

The human hair follicle: a reservoir of CD40+ B7-deficient Langerhans cells that repopulate epidermis after UVB exposure.

The ability of skin to maintain its protective structural and functional integrity depends on both resident and circulating cells. Until now, it was thought that dendritic antigen presenting cells of epidermis (Langerhans cells) were replaced by circulating bone marrow derived precursors. Here we show by immunostaining studies of timed biopsies taken from human skin after ultraviolet exposure, that hair follicle is a critical reservoir of Langerhans cells that repopulate epidermis depleted of Langerhans cells by a single four minimal erythema dose of ultraviolet B. Immunostaining with antibodies to thymidine dimers showed that ultraviolet B only penetrated the superficial hair follicle opening, whereas deeper follicle was relatively protected. Langerhans cells migrating from hair follicle into epidermis 72 h after ultraviolet exposure have a partial deficiency of molecules important to T cell costimulation. We used four color flow cytometry to show that Langerhans cells isolated from epidermis 72 h after ultraviolet B can upregulate CD40 but not B7-1 or B7-2 expression in culture, suggesting a different phenotype of hair follicle Langerhans cells. Therefore, the hair follicle is a specialized immune compartment of the skin that serves as an intermediate reservoir of Langerhans cells between bone marrow and epidermis, and that may play a critical role in immune surveillance.

Abnormal IL-4 gene expression by atopic dermatitis T lymphocytes is reflected in altered nuclear protein interactions with IL-4 transcriptional regulatory element.

Among the atopic disease, atopic dermatitis is characterized by the highest levels of serum IgE and by increased peripheral blood T-cell interleukin-4 (IL-4) production. IL-4 promotes IgE synthesis by B cells and stimulates the growth of IL-4-producing T cells and may contribute to the pathogenesis of this disease. In this study, in situ hybridization established that atopic dermatitis patients have a higher frequency of IL-4-producing peripheral blood T cell when compared to normal subjects. These in vivo-derived T cells were used to examine the signaling requirements of IL-4 production and the nuclear factors that associate with a critical IL-4 transcriptional regulatory element between -88 and -60 relative to the IL-4 transcription initiation site, the activation responsive element. We demonstrate that, as in T-cell lines, proteins belonging to the NF-AT and AP-1 family of transcription factors are present in stimulated cell extracts and specifically associate with the activation responsive element. Dysregulated IL-4 production is reflected in the nuclear proteins that associated this element. Using gel shift assays, we found that 12 of 12 nuclear extracts from stimulated atopic T cells formed the activation-dependent protein-DNA complex, compared to only 2 of 12 normal T-cell extracts. Activation complex formation correlated with the relative level of IL-4 mRNA and protein produced in stimulated T cells, suggesting that abnormal IL-4 gene expression in atopic disease may be linked to alterations in nuclear protein interactions with these promoter elements.

Epitope spreading: lessons from autoimmune skin diseases.

Autoimmune diseases are initiated when patients develop aberrant T and/or B cell responses against self proteins. These responses presumably are directed to single immunogenic epitopes on these proteins. Recent data in animal models of autoimmune diseases suggest that the targets of immune responses in autoimmunity do not remain fixed, but can be extended to include other epitopes on the same protein or other proteins in the same tissue, a phenomenon termed "epitope spreading." The "epitope spreading" phenomenon also applies to situations in which tissue damage from a primary inflammatory process causes the release and exposure of a previously "sequestered" antigen, leading to a secondary autoimmune response against the newly released antigen. In experimental autoimmune animal diseases, "epitope spreading" seems to have significant physiologic importance in determining the course and duration of disease. In this paper, we review the current concepts in animal models of autoimmune diseases in order to define the "epitope spreading" phenomenon, and we then propose how this phenomenon might play a significant role in the development and the course of autoimmune skin diseases. Hopefully, an understanding of "epitope spreading" will help the dermatology community to better understand the pathogenesis of autoimmune skin diseases and to rationally fashion disease-specific immune therapy in the future.

Acute erythroderma as an exclusion criterion for idiopathic CD4+ T lymphocytopenia.

BACKGROUND: Idiopathic CD4+ T lymphocytopenia is defined as a CD4+ T lymphocytopenia of less than 0.3 x 10(9)/L that is not associated with human immunodeficiency virus, other immunodeficiency, or immunosuppressive therapy. The associated clinical course and laboratory findings are variable. We describe a subset of patients whose peripheral CD4+ T-lymphocytopenia was transient, and suggest a pathomechanism for this phenomenon. OBSERVATIONS: We describe three patients with cutaneous T-cell lymphoma, atopic dermatitis, or psoriasis in whom acute erythroderma was concomitant with a peripheral CD4+ T lymphocytopenia that normalized after resolution of the erythroderma. Immunoperoxidase staining of skin biopsy specimens and quantitative estimation of CD4+ T lymphocytes in the cutaneous and peripheral blood compartments demonstrated that the peripheral CD4+ T lymphocytopenia in these cases most probably resulted from sequestration of CD4+ T lymphocytes in the skin. The skin of an erythrodermic patient appears capable of sequestering 10(10) to 10(11) CD4+ T lymphocytes, whereas the peripheral blood compartment contains in the range of 10(9) CD4+ T lymphocytes. CONCLUSIONS: We propose that CD4+ T lymphocytopenia can occur as a result of acute erythroderma of multiple causes and that acute erythroderma associated with transient CD4+ T lymphocytopenia be considered as an exclusion criterion for idiopathic peripheral blood CD4+ T lymphocytopenia.

Paraneoplastic pemphigus presenting as a lichen planus pemphigoides-like eruption.

BACKGROUND: Paraneoplastic pemphigus refers to a specific disease entity in which neoplasia is associated with severe mucosal ulceration and polymorphous cutaneous eruptions, sometimes resembling erythema multiforme. Direct immunofluorescence and indirect immunofluorescence on standard substrates are similar to pemphigus vulgaris; however, paraneoplastic pemphigus serum uniquely binds to all epithelia and has distinctive immunoprecipitation characteristics. OBSERVATIONS: A 63-year-old woman with chronic lymphocytic leukemia developed a severe, mucocutaneous, vesiculobullous eruption with the clinical and histopathologic characteristics of lichen planus pemphigoides evolving into a Stevens-Johnson-like presentation and the immunofluorescence findings of pemphigus vulgaris. Evaluation of her serum confirmed the presence of autoantibodies specific for paraneoplastic pemphigus by indirect immunofluorescence and immunoprecipitation criteria. CONCLUSION: The spectrum of paraneoplastic pemphigus must now be expanded to include cases that present clinically and histologically as a lichen planus pemphigoides-like eruption.

Long-term effectiveness and safety of recombinant human interferon gamma therapy for atopic dermatitis despite unchanged serum IgE levels.

OBJECTIVE: To assess the long-term effects of recombinant human interferon gamma treatment of atopic dermatitis (AD). DESIGN: Case series. Patients were treated for up to 24 months. SETTING: University dermatology outpatient clinics in Ann Arbor, Mich, and Portland, Ore. PATIENTS: Twenty-four of 32 eligible patients who participated in a previously reported, 12-week, double-blind, placebo-controlled study of recombinant human interferon gamma treatment for AD were enrolled. INTERVENTION: Patients self-administered recombinant human interferon gamma, 50 microg/m2, by daily subcutaneous injection. MAIN OUTCOME MEASURES: Overall response; body surface area of involvement; clinical severity scores for pruritus, erythema, edema, excoriations, dryness, scaling, and lichenification; other atopic symptoms; and laboratory parameters, including serum IgE levels, were monitored at quarterly visits. Results at 1 and 2 years were compared with baseline values. RESULTS: All efficacy parameters improved (P<.05). For example, pruritus was reduced by 50% after both 1 (n=24, P<.001) and 2 (n=16, P=.005) years. Allergic conjunctivitis and allergic rhinitis also improved (P<.01). Eosinophil counts decreased significantly (P<.001). IgE levels increased. Clinical improvement more closely correlated with changes in eosinophil counts (r=0.3-0.5) than with changes in IgE levels (r=0.0-0.2). Only 1 patient discontinued therapy because of adverse effects (flulike symptoms). CONCLUSIONS: The initial efficacy and adverse effects reported for recombinant human interferon gamma treatment of patients with AD were maintained after 2 years of long-term use. Recombinant human interferon gamma seems to be a well-tolerated and effective agent in the long-term therapy of patients with AD. Therapies that correct cellular immune defects, but not humoral immune defects, may be effective in the treatment of patients with AD.

Lichenoid dermatitis in paraneoplastic pemphigus: a pathogenic trigger of epitope spreading?

BACKGROUND: In select cases, lichen planus has been observed to be a paraneoplastic condition sometimes associated with paraneoplastic pemphigus, a disease featuring autoantibodies directed against plakin proteins, desmogleins 3 and 1, and a still uncharacterized 170-kd antigen. Epitope spreading describes the phenomenon where underlying chronic inflammation leads to the sequential recognition of new epitopes on self-proteins over time. OBSERVATIONS: Five of 6 patients diagnosed as having paraneoplastic pemphigus had concomitant clinical and histological features of lichen planus. In 1 patient, results of the initial indirect immunofluorescence on rat bladder were negative and only 2 of the 5 antigens were identified by immunoprecipitation. After 1 year of worsening disease, repeated testing confirmed the presence of antibodies directed against all 6 of the implicated antigens, supportive of our hypothesis that epitope spreading may occur in paraneoplastic pemphigus. CONCLUSIONS: Lichenoid eruptions may predispose to an early evolutionary stage of paraneoplastic pemphigus. Cell-mediated autoimmunity at the dermoepidermal junction may promote the exposure of self-antigens and the development of subsequent and progressive humoral autoimmunity. As such, paraneoplastic pemphigus may demonstrate epitope spreading in a human, humoral-mediated autoimmune disease.

Diagnosis and treatment of allergic skin disorders in the elderly.

Allergic skin disorders in the elderly may arise from contact with or ingestion of offending allergens. Itching associated with skin allergy must be distinguished from other causes of itching in the elderly such as xerosis, itching due to systemic disease and bullous disease. Although elderly people have somewhat decreased cell-mediated immunity and may be harder to sensitise under experimental conditions, they have had many years to acquire allergic responses, and therefore develop contact dermatitis frequently. Patch testing is a valuable tool to diagnose contact allergy and should be used often in the elderly, particularly in patients at high risk of contact dermatitis, such as those with chronic lower extremity dermatitis or ulcers due to venous stasis. When prescribing topical medications to high risk patients, a knowledge of the common sensitisers is important. In addition to allergy to medicaments and dressings used to treat stasis ulcers, contact allergy to dental prostheses and medications used to treat ocular disease are common in the elderly as a result of increased usage and exposure. Rash caused by ingested allergens is much more commonly due to medications than to food in the elderly. Allergic noneczematous dermatoses in the elderly are commonly drug-induced. Urticarial skin reactions are often associated with the administration of antibacterials, nonsteroidal anti-inflammatory drugs (NSAIDs), antidepressants or opioids. Morbilliform rashes are a common sign of systemic reaction to anticonvulsants, gold, allopurinol or diuretics. Phototoxic reactions may be associated with the administration of tetracyclines, diuretics, NSAIDs and antihyperglycaemic agents. Patient-specific variables such as HLA type and concomitant medication may affect the likelihood of an allergic response to medication. Many elderly patients take multiple medications, which can make diagnosis of drug allergy difficult because diagnosis is most commonly accomplished by observing clinical response once the medication is withdrawn. In the case of lichenoid cutaneous reactions, clinical improvement may take several months after withdrawal of the offending drug. Laboratory tests to detect drug-induced allergic skin disorders may be available in the future.

Basophil histamine release in atopic dermatitis and its relationship to disordered cyclic nucleotide metabolism.

Maximal histamine release (HR) from leucocytes, in response to Concanavalin A (Con A) was significantly higher in a group of 16 adults with moderate to severe atopic dermatitis (AD) when compared to 13 non-atopic adults. In a further 4 adults with AD, HR was similar to that in the normals, suggesting the existence of 'high releaser' and 'low releaser' subsets within the AD group. Leucocyte cyclic AMP phosphodiesterase (PDE) activity was significantly higher in the 'high releaser' group compared to the 'low releaser' and normal groups. High and low HR responses showed strong correlations with high and low PDE. Pre-treatment of leucocytes from 'high releasers' with the experimental PDE PDE inhibitor RO-20-1724 reduced the HR to normal levels. These findings suggest that increased histamine 'releasability' in AD is related to abnormalities in cyclic nucleotide regulation. No significant HR could be demonstrated in response to a range of concentrations of methacholine in 'high releaser' atopics and normals. Methacholine also did not affect HR in response to maximal Con A stimulation in 'high releaser' atopics. Basophil percentages within the leucocyte preparation and the histamine content per basophil, were not significantly different between the atopics and normals. Con A-stimulated histamine release did not correlate significantly with serum IgE levels.

Mapping the literature of cytotechnology.

The major purpose of this study was to identify and assess indexing coverage of core journals in cytotechnology. It was part of a larger project sponsored by the Nursing and Allied Health Resources Section of the Medical Library Association to map the literature of allied health. Three representative journals in cytotechnology were selected and subjected to citation analysis to determine what journals, other publication types, and years were cited and how often. Bradford's Law of Scattering was applied to the resulting list of cited journals to identify core titles in the discipline, and five indexes were searched to assess coverage of these core titles. Results indicated that the cytotechnology journal literature had a small core but wide dispersion: one third of the 21,021 journal citations appeared in only 3 titles; another third appeared in an additional 26 titles; the remaining third were scattered in 1,069 different titles. Science Citation Index Expanded rated highest in indexing coverage of the core titles, followed by MEDLINE, EMBASE/Excerpta Medica, HealthSTAR, and Cumulative Index to Nursing and Allied Health Literature (CINAHL). The study's results also showed that journals were the predominantly cited format and that citing authors relied strongly on more recent literature.

Impact of changing health care economics on Michigan hospital libraries: report of a survey.

In an attempt to determine how efforts to contain the soaring cost of U.S. health care in the 1980s have affected the size and stature of Michigan hospital libraries, a survey was sent out in April 1988 to 156 hospitals across the state. Fifteen of the 97 responding institutions did not maintain libraries during the survey period and were subsequently excluded from the study. Total FTEs in the 82 responding libraries decreased by 6.1%. In the 69 libraries reporting budget data, materials budgets increased, but by less than 7% a year. Eighteen of the 82 libraries had positions reclassified, with 12 (14.6%) assigned downgrades. The trend toward reduced size and perceived value of hospital libraries that emerged from the survey points to the need for regular collection of comprehensive hospital library statistics to assist hospital librarians in effective direction of their profession's course.

Suppressor T cell-activating macrophages in ultraviolet-irradiated human skin induce a novel, TGF-beta-dependent form of T cell activation characterized by deficient IL-2r alpha expression.

Because UV-induced epidermal macrophages (UV-Mph) preferentially activate CD4+ T suppressor-inducer cells and induce tolerance, we hypothesized that they differentially up-regulate T cell early activation genes compared with constitutive epidermal APC, Langerhans cells. We used epidermal cells from UV-exposed (UV-EC) and control (C-EC) human skin to stimulate allogeneic CD4+ T lymphocytes. Reverse transcriptase-PCR revealed that both C-EC (Langerhans cells) and UV-EC (UV-Mph) induced 10(3)- to 10(6)-fold increases in IL-2 mRNA. However, while T cells stimulated by C-EC for 48 h showed a greater than 10(3)-fold increase in IL-2R alpha mRNA, those stimulated by UV-EC did not (n = 5, p = 0.004). Flow cytometry demonstrated that 4.1 +/- 2.3% of unstimulated CD4+ lymphocytes expressed cell surface IL-2R alpha, which increased to 15.7 +/- 1.8% upon stimulation by C-EC for 48 h, but stimulation by UV-EC failed to increase the IL-2R alpha+ population (n = 3, p = 0.038). The addition of neutralizing anti-TGF-beta Abs to UV-EC-stimulated cultures restored CD4+ cell surface IL-2R alpha expression to 12.9 +/- 0.2%. CD4+ T cell activation by UV-Mph is distinct from previously described models of tolerance such as Th2 activation (IFN-gamma mRNA was induced and IL-4 mRNA was not) and Th1 anergy (IL-2 mRNA levels induced by UV-EC and C-EC were similar). Furthermore, costimulatory signals were provided by UV-Mph; CTLA4-Ig and LFA-3-Ig fusion proteins and Abs to CD2, LFA-3, LFA-1, and ICAM-1 inhibited UV-Mph-induced T cell proliferation. Thus, the altered immune outcome induced by UV-Mph (tolerization) compared with Langerhans cells (sensitization) is reflected as a novel mechanism of initial CD4+ T cell early activation gene expression characterized by TGF-beta-dependent deficient IL-2R alpha expression.

Functional desensitization due to stimulation of cyclic AMP-phosphodiesterase in human mononuclear leukocytes.

We have previously demonstrated heterologous desensitization of human mononuclear leukocytes (MNL) by incubation of low (e.g., 10(-6)M) concentrations of histamine, isoproterenol and prostaglandin E1. Subsequent exposure of the cells to stimulating (e.g., 10(-3) to 10(-5)M) concentrations of any one of the three agonists shows reduced cAMP responses. Possible mechanisms for the subnormal responsiveness include rapid degradation of cAMP. In this report we demonstrated time-dependent elevation of cAMP-phosphodiesterase (PDE) activity following agonist desensitization. The increased enzyme activity was accompanied by a mirror-image decrease in cAMP responsiveness. The effect was rapid and prolonged, with recovery time proportional to desensitization time. Cycloheximide failed to inhibit the increase of cAMP-PDE activity caused by short-term histamine exposure, but partially diminished the elevation as the result of chronic histamine desensitization. We observed three different kinetic forms of cAMP-PDE in MNL, designated as I, II and III, each with distinctive Km and Vmax. Histamine desensitization increased the activity of form II and drastically reduced that of form I. Also we observed a possible conversion of lymphocyte cAMP-PDE from form I to the form II more characteristic of monocytes. Agonist-induced increases in cAMP-PDE activity and changes in enzyme kinetic characteristics represent a potentially important mechanism of functional desensitization. This may have significant effects on biological regulation of cyclic nucleotides.

Low expression of CD40 and B7 on macrophages infiltrating UV-exposed human skin; role in IL-2Ralpha-T cell activation.

After UV exposure of skin, epidermal Langerhans cells (LC) are depleted, whereas CD11b+CD36 CD1a- monocytes/macrophages (UV-Mphi) infiltrate. Different immunological outcomes in vivo are mediated by LC (sensitization) and UV-Mphi (tolerance) which may be related to the distinct T cell activation states that these antigen-presenting cells (APC) induce. We previously demonstrated that CD4+ T lymphocytes activated by UV-Mphi are, in contrast to LC-activated T cells, IL-2Ralpha deficient, and we hypothesize that this differential T cell activation is related to differences in co-stimulatory molecules between UV-Mphi and LC. Using four-color flow cytometry, we found a reduced capacity to up-regulate expression of the important co-stimulatory molecules CD40, B7-1 and B7-2 by UV-Mphi relative to LC. This alteration in co-stimulatory molecule expression was selective, because UV-Mphi express equal levels of ICAM-1 and ICAM-3, and increased levels of LFA-1, relative to LC. After bidirectional signaling with T cells during alloantigen presentation, UV-Mphi still exhibited less CD40 and B7-1 than LC. Addition of IFN-gamma induced CD40 and B7-1 expression on UV-Mphi and restored IL-2Ralpha expression on UV-Mphi-activated T cells but had no effect on IL-2Ralpha on resting or LC-activated T cells. The restoration of IL-2Ralpha expression on UV-Mphi-activated T cells by IFN-gamma was inhibited (67 %, p = 0.005) by addition of neutralizing anti-CD40. Therefore, differences in co-stimulatory molecule expression, in particular CD40, on UV-Mphi and LC are critical in determining the distinct T cell activation induced by these APC.

Protection against UV-induced suppression of contact hypersensitivity responses by sunscreens in humans.

Both in vivo skin immune responses and the skin's reaction to sun exposure integrate a complex interplay of biologic responses. The complexity and multiplicity of events that occur in the skin during an immune response make it a sensitive indication of both UVB and UVA-induced changes in the skin by sun damage, as well as those changes that are prevented by various sunscreens. Sunscreens are the most effective and widely available intervention for sun damage, other than sun avoidance or clothing. However, sunscreens vary widely in their relative ability to screen various UV waveband components, and their testing has been variably applied to outcomes other than for erythema to determine the sunburn protection factor (SPF), a measure primarily of UVB filtration only. Determination of an immune protection factor (IPF) has been proposed as an alternative or adjunctive measure to SPF, and recent studies show IPF can indeed detect added in vivo functionality of sunscreens, such as high levels of UVA protection, that SPF cannot. Clarification of the definition of IPF, however, is required. Excellent data are available on quantification of the IPF for restoring the afferent or induction arm of contact sensitivity, but other immune parameters have also been measured. Proposed here is nomenclature for whether the IPF is measured using contact sensitivity induction (IPF-CS-I), contact sensitivity elicitation (IPF-CS-E), delayed-type hypersensitivity elicitation (IPF-DTH-E), antigen-presenting cell function (IPF-APC-FXN) or numbers (IPF-APC-#), and cytokine modification such as IL-10 (i.e. IPF-cyto-IL-10). Similar nomenclatures could be used for other measures of skin function protection (i.e. DNA damage, p53 induction, oxidation products, etc.). A review of in vivo human studies, in which sunscreens are used to intervene in a UV-induced modulation of immune response, cells or cytokines, highlights the technical variables and statistical approaches which must also be standardized in the context of an IPF for regulatory or product claim purposes. Development of such IPF standards would allow the integration of both UVB and nonUVB (UVA, blue and possible IR) solar waveband effect-reversals, could be applied to integrate effects of other ingredients with protective function (i.e. antioxidants, retinoids, or other novel products), and would spur development of more advanced and complete protection products.

A clinical and histologic mycosis fungoides simulant occurring as a T-cell infiltrate coexisting with B-cell leukemia cutis.

One year after the onset of chronic lymphocytic leukemia, an elderly man had scaly cutaneous plaques on the thighs that clinically and histologically resembled the mycosis fungoides type of cutaneous T-cell lymphoma. Two years later the patient had indurated, red dermal nodules on the face that clinically and histologically were characteristic of cutaneous chronic lymphocytic leukemia. Immunophenotyping results from a facial nodule confirmed the presence of a B-cell infiltrate (CD20+). Immunophenotyping of a lesion on the right thigh showed that half the cells were composed of a CD2+, CD45RO+ (UCHL-1+) upper dermal and focally epidermotropic population of T cells consistent with mycosis fungoides; however, these T cells coexisted with an equal number of CD20+ B cells arranged in distinct clusters. DNA from the thigh lesion exhibited a B-cell immunoglobulin gene rearrangement, but the T-cell receptor gene rearrangements were germline. In this case, the evidence favors a mycosis fungoides simulant occurring as a reactive T-cell infiltrate to an underlying B-cell chronic lymphocytic leukemia.