Lichen planus and chronic graft-versus-host reaction. In situ identification of immunocompetent cell phenotypes

Histologic Patterns of Polyethylene Glycol-liposomal Doxorubicin-related Cutaneous Eruptions

Polyethylene glycol (PEG)-liposomal doxorubicin (Stealth R, Doxil) is a formulation of doxorubicin, which is encapsulated in liposomes formulated with PEG. It is favored in the palliative setting over doxorubicin because of its generally favorable side effect profile. Adverse reactions are predominantly skin eruptions. We report 3 cases of women with breast cancer undergoing treatment with liposomal doxorubicin who developed palmar-plantar erythrodysesthesia and diffuse morbilliform eruptions. Biopsies in the 2 cases demonstrated vacuolar interface dermatitis with epidermal dysmaturation and the third case suggested a drug eruption. Additionally, we report a woman with metastatic breast cancer who developed a similar morbilliform eruption soon after completing a regimen of liposomal doxorubicin. The biopsy revealed an atypical squamous proliferation showing epidermal dysmaturation with focal evidence of interface damage. Both clinician and pathologist alike should be cognizant of this cutaneous eruption, as well as the histologic patterns.

'Activation-induced cell death': a special program able to preserve the homeostasis of the skin?

The 'activation-induced cell death' (AICD) is a molecular system leading to death of antigen-activated T lymphocytes, in order to avoid accumulation of harmful cytokine-releasing cells. This article reviews both the molecular mechanisms working in AICD and the role played by such mechanisms in preventing a number of skin diseases. Specifically, because AICD removes activated and autoreactive T cells through a CD95-/CD95-L-mediated suicide, skin diseases were scrutinized in which such valuable machinery could be lacking. Indeed, at least some inflammatory skin diseases, including psoriasis and atopic dermatitis, can be sustained by an increased survival of activated T lymphocytes associated with deficient CD95-/CD95-L-mediated AICD of such strong pro-inflammatory cells. In addition, autoreactive skin diseases, including, e.g. alopecia areata, lichen planus and other lichenoid tissue reactions, can be related to autoreactive T lymphocytes which could be unable to undergo CD95-/CD95-L-mediated AICD. Finally, a lack of AICD may be executive even in favoring cutaneous T cell lymphoma. Thus, because inflammatory, autoreactive and neoplastic skin diseases can be associated with a deficient CD95-/CD95-L-mediated suicide of activated T cells, AICD is likely to represent a fundamental program to preserve the homeostasis of the skin. Therapeutic approaches able to restore the AICD machinery promise to successfully treat such relevant skin diseases.

Sparfloxacin-induced photosensitivity and the occurrence of a lichenoid tissue reaction after prolonged exposure

BACKGROUND

A new antibacterial quinolone, sparfloxacin (SPFX), frequently causes photosensitive dermatitis and sometimes induces a treatment-resistant lichenoid tissue reaction (LTR).

OBJECTIVE

We attempted to determine the factors that induce LTR in SPFX-induced photodermatitis.

METHODS

Thirteen patients with SPFX photosensitive dermatitis were studied clinically and histopathologically.

RESULTS

Six of the 13 patients had acute dermatitis with epidermal spongiosis and focal epidermal HLA-DR and intercellular adhesion molecule-1 (ICAM-1) expression with CD4+ cell infiltration. The other seven displayed LTR with basal cell liquefaction degeneration and diffuse epidermal HLA-DR and ICAM-1 expression associated with CD8+ cells. The seven patients with LTR were exposed to UV and SPFX for more than 2 weeks after the appearance of their initial eruption, whereas the six patients with acute dermatitis were treated within 2 weeks. The acute dermatitis lesions cleared significantly within 2 weeks, but the LTR lesions persisted for more than 6 weeks.

CONCLUSION

Patients with quinolone-induced photosensitivity should be treated within 2 weeks of onset to prevent LTR.

An erythema multiforme-like eruption caused by exposure to 1-chloromethylnaphthalene

A young male patient developed an erythema multiforme-like eruption following an accidental exposure to 1-chloromethylnaphthalene (1-CMN). In addition to the skin lesion, he suffered from liver involvement and tear insufficiency. Positive results of a patch test with 1-CMN and an in vitro lymphocyte transformation test suggested that direct exposure of the skin to chemical compounds was the probable cause of his symptoms.

Expression of CD1 and HLA-DR by Langerhans cells (LC) in oral lichenoid drug eruptions (LDE) and idiopathic oral lichen planus (LP)

Numbers of Langerhans cells (LC) expressing the common thymocyte antigen (T6/CD1) are similar in oral lichen planus (LP) and in normal oral epithelium; however, expression of class II major histocompatibility antigens (HLA-DR/Ia) by Langerhans cells is greater in lichen planus than in normal epithelium, a phenomenon believed to be associated with activation and antigen presentation. This study quantified the numbers of T6+ve and HLA-DR + ve Langerhans cells in oral lichen planus and lichenoid drug eruptions (LDE) to investigate whether differences may reflect differing routes of antigen presentation. Six patients with oral lichenoid drug eruptions and six control idiopathic oral lichen planus patients had lesional biopsies. An immunoperoxidase technique was used to demonstrate binding of T6 and HLA-DR antibodies to identify dendritic intraepithelial cells as Langerhans cells and activated Langerhans cells, respectively. In lichenoid drug eruptions, the number of HLA-DR + ve LC was significantly lower than the number of T6 + ve LC (P < 0.05), whereas in idiopathic lichen planus the numbers of T6 + ve and HLA-DR + ve LC did not differ significantly (P = 0.20). The results provide evidence for differences in the routes of antigen presentation in lichenoid drug eruptions and idiopathic lichen planus.

Langerhans' cells are depleted in chronic graft versus host disease

AIMS

To measure Langerhans' cells in skin of patients treated by bone marrow transplantation who developed chronic graft versus host disease (GvHD); to determine whether the reduction in Langerhans' cells resulted directly from the GvHD or from other factors, such as the immunosuppressive regimens used in bone marrow transplant patients.

PATIENTS AND METHODS

Lesional and nonlesional skin specimens from nine patients with lichen planus-like lesions and three patients with sclerodermoid lesions were studied. Control skin specimens were taken from three patients undergoing breast reduction surgery. The number of Langerhans' cells/mm2 and the area of Langerhans' cells as a percentage of total epidermis were measured by counting cells labelled with antihuman CD1a.

RESULTS

A significant reduction in Langerhans' cell area and number were found in specimens with lesions (area 3.5%; number 507/mm2) compared with specimens without lesions (8.42%; 2375/mm2). In contrast, Langerhans' cell area and number in skin without lesions were similar to controls (10.26%; 2968/mm2).

CONCLUSIONS

Langerhans' cells were significantly reduced in skin with lesions of chronic GvHD but not in skin without lesions from the same patient, suggesting that the reduction is a direct consequence of GvHD and not linked to immunosuppressive drugs or late effects of conditioning regimens. In long term bone marrow transplant recipients, Langerhans' cells are derived mainly from the donor cells; therefore, this result suggests the occurrence of autoreactive phenomenon in chronic GvHD.

Detection of T lymphocytes and T lymphocyte subsets in lichen planus: in situ and in peripheral blood

BACKGROUND

Abnormal immune mechanisms are thought to be important in the pathogenesis of lichen planus (LP). This is a study to clarify the changes that occur in T lymphocytes and T lymphocyte subsets, both in situ and in peripheral blood.

METHODS

A group of 100 patients with LP were included in this study. T lymphocytes and T lymphocyte subsets were detected in lesional skin by immunoperoxidase cell surface staining using monoclonal antibodies. Peripheral T lymphocytes and T lymphocyte subsets were also detected by indirect immunofluorescence using monoclonal antibodies. A group of 10 normal healthy subjects were used as controls.

RESULTS

The study of the lesional T lymphocytes and T lymphocyte subsets demonstrated that helper T cells was the predominant subset in LP lesions in most of the patients. This predominance was evident irrespective of the duration of the disease and was more evident in late than in early lesions. The percentage of both total T lymphocytes and helper T cells in peripheral blood was decreased significantly in patients compared with controls. A significant decrease in helper T cells and the helper/cytotoxic T cell ratio was detected in patients with a longer duration of the disease.

CONCLUSION

Activation of helper T lymphocytes that were found to be the predominant subsets in LP lesions may be responsible for epidermotropic cellular infiltrates leading to damage and destruction of epidermal cells.

Is there a role for tumor necrosis factor-alpha (TNF-alpha) in oral lichen planus?

Oral lichen planus (OLP) is a T cell-mediated inflammatory disease of the oral mucosa. T lymphocytes accumulate within OLP lesions by extravasation from the local microvasculature and subsequent migration to the oral epithelium. Tumor necrosis factor-alpha (TNF-alpha) is a cytokine involved primarily in T cell-mediated immunopathological reactions, and it is implicated in diseases which bear clinical and histological similarities to OLP. This review examines the role of TNF-alpha in the initiation and progression of OLP, and summarises evidence for a key role for TNF-alpha in this disease. A unifying hypothesis for the involvement of TNF-alpha in the immunopathogenesis of OLP is presented. Based on this model, a variety of current therapies are explained and several alternative approaches suggested.

Mucosal cell-mediated immunological changes associated with experimental graft-versus-host disease

This study examined the histological changes and local cellular immune response induced within the lingual mucosa in an allogeneic F1 hybrid rat model of graft-versus-host disease (GvHD) with a view to studying oral lymphocyte-epithelial cell reactions. Highest levels of disease, as reflected by both a GvHD index and the extent of the oral mucosal changes, were obtained using primed donor (Lewis rats) splenocytes and irradiated hosts (Lew/Da rats). The lingual mucosae of test animals were characterised by irregular epithelial keratosis, an absence of basal cell liquefaction and a diffuse inflammatory cell infiltrate, histological features consistent with an oral lichenoid tissue reaction. Immunohistochemical studies showed that mucosal involvement was characterised by infiltration of the lamina propria by NK cells (CD8+, CD5-), "activated" cells (CD25+) and T cells (CD5+) with selective migration of the latter, including a CD5+, CD8- subset (helper/inducer T cell), into the epithelium. Epithelial expression of Ia was invariably associated with these inflammatory cell infiltrates and correlated with the GvHD index. These findings suggest the presence of local mucosal T cell activation in the absence of detectable epithelial cell damage, which may be equivalent to the early initiating events in the pathogenesis of oral lichen planus. However, whilst experimental graft-versus-host disease appears to be a useful model for studying lymphocyte-epithelial interactions, the induced oral mucosal changes are more consistent with a lichenoid reaction rather than lichen planus.

Mechanisms of drug eruptions: Part I

The pathogenetic mechanisms underlying common, and less common but severe, adverse cutaneous drug reactions are reviewed. Pharmacogenetic variability may account for a susceptibility to serious drug reactions to sulphonamides and anticonvulsants, as well as to lupus erythematosus (LE)-like syndrome. Exanthematous drug reactions may have an immunological basis. Cell mediated cutaneous drug reactions, including lichenoid reactions, LE-like syndrome, fixed drug eruption, erythema multiforme, Stevens-Johnson syndrome and toxic epidermal necrolysis, will inevitably involve elements of the skin immune system. Graft-versus-host disease provides a useful model for aspects of these drug-induced disorders. Urticaria, angioedema, anaphylaxis and anaphylactoid reactions may involve Type I immunoglobulin (Ig)-mediated or Type III hypersensitivity, or may be caused by pharmacological, non-allergic means. Drug-induced vasculitis, serum sickness and the Arthus phenomenon are manifestations of the immune complex disease. Drug-induced pemphigus may involve immune dysregulation, but several thiol-containing drugs are able to cause antibody-independent acantholysis directly.

Quantitative cellular and nuclear volumetric alterations in epithelium from lichen planus lesions of human buccal mucosa

Patients with oral lichen planus lesions may represent a relatively high risk population for subsequent development of oral cancer. Little is known of the relative effects of chronic inflammation and the process of malignant transformation itself on the histological structure of transforming epithelia. We have assessed cellular and nuclear volumes in defined basal and spinous cells from normal buccal mucosa epithelium, from epithelium associated with a non-specific chronic inflammatory infiltrate and from lichen planus lesions. Normal (N) tissues were obtained from the margins of non-neoplastic buccal mucosa lesions. Inflammatory (INF) lesions were from areas of the buccal mucosa diagnosed clinically as traumatic irritation without ulceration, and lichen planus (LI) lesions were biopsied from areas exhibiting Wickham's striae. Basal and spinous epithelial cells from normal and pathological human buccal mucosa were measured on haematoxylin and eosin-stained sections imaged through a video camera using a Zeiss VIDAS analyser and from these measurements, nuclear (VN) and cellular (VCELL) volumes were determined. VN and VCELL derived for both basal and spinous strata were similar in N and INF groups but were almost doubled in the LI group. Comparisons between LI and all other groups were significantly elevated. The effects of the inflammatory infiltrate on the oral epithelium in lichen planus and in non-specific inflammation thus differ significantly. VN and VCELL may serve as potential discriminators between benign lesions and premalignant lichen planus.

Phenotypic determination of T-lymphocytes responding to chemotactic stimulation from fMLP, IL-8, human IL-10, and epidermal lymphocyte chemotactic factor

Human T lymphocytes were collected after they had migrated towards N-formyl-methionyl-leukylphenylalanine (fMLP), rIL-8, human IL-10 (hIL-10), and epidermal lymphocyte chemotactic factor (ELCF). They were stained for determination of their phenotype by FACS analysis using anti-CD4, -CD8, -CD18, -CD45R0 and OPD4 antibodies. Human IL-10 increased the percentage of CD8+ T lymphocytes in the migrating cell population by 152% compared with cells migrating towards the medium and decreased the number of CD4+ T lymphocytes by 79%. ELCF increased the number of CD4+ T lymphocytes by 18%, and the number of CD45R0+ T lymphocytes by 52%, while the number of CD8+ T lymphocytes was decreased by 20%. rIL-8 increased the number of CD4+ T lymphocytes and decreased the CD8+ T lymphocytes. The distribution of the different subpopulations of T lymphocytes was not changed significantly by fMLP. The observed changes in the phenotypes did not occur when incubating T lymphocytes with the chemotaxins. Our observations demonstrate that individual chemotactic factors will attract specific subsets of T lymphocytes. They may help to explain the predominance of memory T lymphocytes (CD4R0+, CD4+) in allergic contact dermatitis and certain other skin diseases. They also confirm the results of a recent study, that showed hIL-10 to be selectively chemotactic for CD8+ T lymphocytes.

A comparative immunological analysis of the oral mucosa in chronic graft-versus-host disease and oral lichen planus

Oral mucosal biopsies of 12 allogeneic marrow transplant recipients with chronic graft-versus-host disease (GVHD) involving the mouth were compared with biopsies taken before transplantation. They were also compared with biopsies from otherwise healthy patients with oral lichen planus, and with those from a control group of normal individuals. Biopsies from chronic GVHD exhibited a low number of infiltrating T lymphocytes (CD3 cells) compared with those from oral lichen planus, which showed intense cell infiltration (p less than 0.005). The ratio of CD4 to CD8 cells in biopsies taken after the manifestation of chronic GVHD exhibited no consistent variation compared with those taken before transplantation or with biopsies of oral lichen planus. The CD4/CD8 ratio in all groups investigated varied between 4:1 and 6:1. The number of natural killer cells (CD57), was increased in biopsy specimens taken before transplantation compared with the other groups. The frequency of homing receptor, Leu-8 bearing T cells was low in the biopsy specimens of all groups, compared with the corresponding frequency in peripheral blood (10-45 and 60-90%, respectively; p less than 0.001). In the biopsies from chronic GVHD and oral lichen planus the number of lymphocytes with transferrin receptors was increased compared with the pretransplant and control groups. Virtually no infiltrating cells were carrying interleukin-2 receptors (CD25) in any of the groups studied. Langerhans cells (CD1) were more frequently found in the specimens from chronic GVHD and oral lichen planus than in the pretransplant specimens and the control group (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

The oral mucosa as a mirror of general health or disease

There is a close relationship between general health/disease and oral mucosal reactions. Many diseases show unspecific or specific changes which may evolve throughout the course of the disease but the mucosal reaction may also constitute the initial clinical sign of the disease. Among the broad spectrum of conditions/diseases, three have been selected for this review--HIV/AIDS, Sjögren's syndrome and lichen planus. They illustrate how general disease may be mirrored in the oral mucosa. An attempt has been made to describe the scientific frontiers and to select pertinent key or review articles or books from among the huge amount of literature published in recent years.

Diagnosing and managing oral lichen planus

Lichen planus is a chronic and recurrent inflammatory disease characterized by unpredictable exacerbations and remissions. It affects the skin and/or mucous membrane in nearly 2 percent of the adult population. The symptoms are transient, but clinical evidence of oral disease is more persistent.

Sequential immunopathologic study of oral lichen planus treated with tretinoin and etretinate

Twenty-five patients with oral lichen planus confirmed by histologic examination were divided into three groups: 10 patients received topical treatment with tretinoin, 10 received systemic treatment with etretinate, and the five remaining patients, who received no treatment, served as a control group. An immunopathologic study with the use of monoclonal antibodies was carried out before and after the 3-month course of treatment and showed a variation in the distribution and phenotype of inflammatory cells. No difference between the two types of treatment was observed, but treated patients had a shorter evolution of the disease when compared with control patients.

Immunopathogenesis of oral lichen planus

Oral lichen planus (LP) is a common mucosal disorder in which cell mediated immunity is thought to play a major role. In this paper, a unifying hypothesis which attempts to integrate cellular and molecular signals in the local immune response in oral LP is presented. In this model, modified keratinocyte surface antigens are the target for the cytotoxic cell response which characterizes oral LP, whereas mast cells and antigen presenting Langerhans cells are key cellular elements in the evolving lesion. It has been established that mast cell degranulation induces adhesion molecule expression on endothelium which facilitates lymphocyte homing to the tissues. These adhesive interactions between lymphocytes and keratinocytes are postulated to be important determinants in the effector phase of the lesion. Cytokines produced by both lymphocytes and keratinocytes which influence the local immune response could promote chronicity. Accordingly, modulation of immunologic events is a potential therapeutic approach for oral LP.

Oral lichen planus: the clinical, historical, and therapeutic features of 100 cases

Lichen planus is a chronic inflammatory epidermal and mucosal disease, the cause of which is poorly understood. We reviewed the clinical and historic features of 100 patients referred to our clinic for diagnosis and management of lichen planus. The age, gender, chief complaint, duration of the chief complaint, medical history, medications, and clinical findings were recorded. Past therapeutic modalities were reviewed. Of therapeutic significance, 25 patients with oral lichen planus had a secondary oral candidiasis. Management of symptomatic lichen planus with topical and systemic steroid is discussed. The pharmacology of topical and systemic steroid usage and the rationale for treatment are discussed.

Castleman's tumor and erosive lichen planus: coincidence or association?Report of a case

The rare association of severe erosive lichen planus and Castleman's tumor is presented. Castleman's tumor, or giant lymph node hyperplasia, is a benign neoplasm resembling thymic tumors and is associated with several immunologic abnormalities. Lichen planus also is associated with immunologic defects. One hypothesis linking these two diseases is that lymphocytes may become sensitized to tumor antigens on the Castleman's tumor and attack cross-reacting structures in the skin and other stratified squamous mucosae to produce the clinical picture of lichen planus.

Chronic actinic dermatitis: an immunohistologic and photobiologic study

Photobiologic, histologic, and immunohistochemical findings in 14 patients with chronic actinic dermatitis were compared. Grading of routine histologic features of involved skin demonstrated a spectrum of abnormalities ranging from changes resembling chronic dermatitis to those of cutaneous T cell lymphoma. Immunohistochemical staining showed dermal infiltrates to consist predominantly of T lymphocytes, with a significant trend toward lower CD4+/CD8+ ratios in cases with more florid histologic findings. Circulating CD4+/CD8+ cell ratios were normal in five patients and reduced in one patient. Photosensitivity extending to wavelengths longer than 340 nm was detected in eight patients, but the spectrum of photobiologic abnormality did not appear to correlate with either grading of histologic severity or variation in T cell subsets in lesional skin.

Actinic reticuloid: immunohistochemical analysis of the cutaneous infiltrate in 13 patients

An immunohistological study on cryostat sections of skin biopsies in 13 patients with actinic reticuloid has been performed using a panel of 21 monoclonal antibodies against lymphoid and non-lymphoid infiltrate cells. The infiltrate consisted of activated T cells, numerous histiocytes and macrophages, and small numbers of B cells. In 10 out of 13 patients the majority of the lymphocytes expressed the phenotype of suppressor cells. The number of Leu 8+ cells was inversely proportional to HLA-DR expression by the dermal infiltrate, which suggested a negative correlation between a state of activation and the concentration of Leu 8+ cells. There was a striking number of IgE bearing dendritic cells in the dermis associated with elevated serum IgE levels.

Erythema dyschromicum perstans. Immunopathologic studies

Immunopathologic studies of a patient with clinical and histologic evidence of erythema dyschromicum perstans revealed Ia antigen expression on epidermal keratinocytes, pronounced OKT4 and OKT6 staining of epidermal dendritic cells, and dermal infiltration of T lymphocytes of both helper-inducer (OKT4) and suppressor-cytotoxic (OKT8) phenotypes--a pattern commonly associated with lichen planus. These findings, taken in conjunction with positive IgG staining on colloid bodies, suggest the possibility that erythema dyschromicum perstans and lichen planus have similar disease processes.

Predominance of "memory" T cells (CD4+, CDw29+) over "naive" T cells (CD4+, CD45R+) in both normal and diseased human skin

Absolute numbers of CD3+ T lymphocytes and their subpopulations were determined and statistically evaluated in the lesional skin of psoriasis, atopic dermatitis, nummular dermatitis, pityriasis rosea, and lichen planus. Skin sections were divided into horizontal layers and the numbers of CD3+ T cells as well as CD4+ inducer and CD8+ suppressor-cytotoxic T-cell subsets were counted. In addition, absolute numbers of the two subpopulations of inducer T cells, i.e., "memory" (4B4+ 2H4-) and "naive" (4B4- 2H4+) were evaluated. Unexpectedly, epidermal infiltration by T cells was highest in psoriasis and lowest in atopic dermatitis. In most cases, this exocytosis was dominated by CD8+ suppressor/cytotoxic T lymphocytes, with a minimal epidermal mean CD4/mean CD8 ratio of 0.04 in pityriasis rosea and a maximum of 0.48 in psoriasis. Inducer T cells within the epidermis were almost exclusively of the 4B4+ 2H4- "memory" T-cell subpopulation, whereas 4B4- 2H4+ "naive" T cells were extremely uncommon in lesional epidermis. Similar results were obtained for dermal T cells in all diseases studied, i.e., 4B4- 2H4+ "naive" T cells were relatively rare. Papillary dermis infiltration by T cells was highest in lichen planus where a mean CD4/mean CD8 ratio of 1.10, the minimum in this comparative study, was obtained. The mean CD4/mean CD8 ratio of the papillary infiltrate was highest in atopic dermatitis (4.12). Our results indicate disease-specific and significantly different infiltration patterns of T-lymphocyte subsets in the chronic inflammatory dermatoses investigated.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of Langerhans cells in epidermotropism of T cells

Certain T lymphocytes display a specific affinity for the epidermis (epidermotropism). Recent studies have suggested that Ia+ Langerhans cells (LCs) are possible targets for the epidermotropism. A variety of self-Ia-reactive cloned T cells were tested for their ability to migrate into the epidermis following intradermal inoculation into the footpads of syngeneic mice. Clone BB5 was chosen as representative of the epidermotropic T cells. We investigated whether the depletion of Ia+ LCs from the epidermis by tape-stripping could alter the migration of BB5 cells into the epidermis. The epidermal invasion of BB5 cells was markedly impaired in those mice whose LCs were depleted by 95% after repetitive tape-stripping. Because production of epidermal-derived thymocyte activating factor (ETAF) by the epidermal cells was augmented after repetitive tape-stripping, the diminished migration of BB5 cells into tape-stripped epidermis did not result from a decrease in ETAF production which is thought to attract T cells chemotactically. These results suggest that Ia+ LCs may play an inductive role in the preferential migration of T cells into the epidermis.

Histologic characteristics of lichen planus transplanted onto nude mice and cultured in vitro

Typical confluent lesions of lichen planus were transplanted onto nude mice and cultured in organ culture. The characteristic histologic appearance of lichen planus disappeared after grafting and became similar to normal skin within 6 weeks on nude mice; the dense lymphocyte infiltrate in dermis disappeared, the basal cell layer normalized, and the colloid bodies disappeared from epidermis, although some of them were found in dermis. The granular layer also normalized, but the stratum corneum remained hyperkeratotic 6 weeks after transplantation. In organ culture, characteristic histologic features of lichen planus disappeared in 3-5 days via a rapid necrosis of the upper part of the epidermis and formation of a new, normal-looking basal epidermis. These results suggest that lesions of lichen planus are primarily dependent on the influence of the host to maintain their typical histologic appearance.

Immunohistology of pityriasis lichenoides et varioliformis acuta and pityriasis lichenoides chronica. Evidence for their interrelationship with lymphomatoid papulosis

Pityriasis lichenoides et varioliformis acuta and pityriasis lichenoides chronica are idiopathic, papular eruptions that exhibit certain clinicopathologic similarities to each other and to lymphomatoid papulosis. In order to determine if these disorders are also similar immunologically, we studied the immunopathology of five biopsy specimens from three cases of pityriasis lichenoides et varioliformis acuta and three biopsy specimens from three cases of pityriasis lichenoides chronica. We then compared them to our prior immunohistologic study of nine cases of lymphomatoid papulosis. Pityriasis lichenoides et varioliformis acuta and pityriasis lichenoides chronica both exhibited a dermal and epidermal infiltrate of CD4+ and CD8+ T cells expressing activation antigens. These were admixed with numerous macrophages. The lesional epidermis was diffusely human lymphocyte antigen (HLA)-DR+ and contained decreased CD1+ dendritic cells. Endothelial cells were also HLA-DR+. Cells bearing the phenotypes of B cells, follicular dendritic cells, or natural killer/killer cells were essentially absent. Except for the lack of large atypical cells, the results resembled those described previously for lymphomatoid papulosis. These findings indicate that pityriasis lichenoides chronica, pityriasis lichenoides et varioliformis acuta, and lymphomatoid papulosis share several immunohistologic features. Together with certain clinicopathologic similarities, they are consistent with the hypothesis that these three disorders are interrelated.

T-cell growth factor receptor (Tac-antigen) expression in cutaneous lymphoid infiltrates

A total of ninety-four biopsies from normal skin, benign dermatoses, and lesions of human T cell lymphotropic virus type I (HTLV-I)-positive and -negative cutaneous T cell disorders have been examined immunohistologically for reactivity with anti-Tac (monoclonal anti-T cell growth factor receptor). Tac-positive T cells were plentiful in approximately half the specimens, and they were equally frequent in benign and malignant disorders and in HTLV-I-positive and -negative cutaneous T cell disorders. Furthermore, in diseased skin, reactivity with anti-Tac was not confined to T lymphocytes, since it was also a property of dermal macrophages and Langerhans cells, as shown by examination of serial and/or double-stained sections. Comparison with other markers linked to T cell activation and proliferation (i.e., HLA-DR, OKT10 antigen, transferrin receptor, and the Ki-67 nuclear antigen) showed that Tac-antigen expression did not correlate clearly with any of these markers. These data indicate that anti-Tac forms a useful supplement to other monoclonal antibodies for the identification of activated cell subsets in cutaneous lymphoid infiltrates, but they also show that the use of this reagent on cutaneous biopsy specimens is of only limited diagnostic value.

Different in situ distribution patterns of dendritic cells having Langerhans (T6+) and interdigitating (RFD1+) cell immunophenotype in psoriasis, atopic dermatitis, and other inflammatory dermatoses

Dendritic cells bearing Langerhans cell (OKT6+) or interdigitating cell (RFD1+) immunophenotype may be regularly detected within the dermis of chronic skin diseases characterized by a lymphohistiocytic (lymphoreticular) infiltrate. These 2 subsets of antigen-presenting cells within the dermis of lesions of exacerbating chronic plaque psoriasis, exacerbating nummular dermatitis (discoid eczema), atopic dermatitis, allergic contact dermatitis, pityriasis rosea, lichen ruber planus, and cutaneous lupus erythematosus were quantified using computer-assisted morphometry. The mean dendrite length per dermal dendritic cell was significantly higher for RFD1 than for OKT6 (74.4 +/- 0.98 microns vs 70.0 +/- 1.26 microns: p = 0.0023). The mean dendrite length per dermal dendritic cell was remarkably constant for each marker in the various diagnostic categories studied. Disease-specific patterns of total dendrite length and number (expressed per 100 infiltrating mononuclear cells) of these 2 dendritic cell types within the subepidermal infiltrates were obtained. Pityriasis rosea was characterized by its unique high percentage of OKT6+ Langerhans cells. Atopic dermatitis and psoriasis had relatively high percentages of both RFD1+ interdigitating cells and OKT6+ Langerhans cells. Nummular dermatitis had an intermediate number and total dendrite length for OKT6, but was relatively low in RFD1+ cells. Allergic contact dermatitis, lichen planus, and lupus erythematosus had low numbers and dendrite lengths for both dendritic cell subsets. It is suggested that pityriasis rosea is characterized by an abnormal migration pattern of Langerhans cells. Psoriasis and atopic dermatitis may be examples of diseases in which skin-localized antigen-presenting and T-cell-inducing events are continuously taking place. The other diseases may reflect inflammatory processes in which local antigen presentation is less relevant to the tissue reaction.

Lichenoid tissue reaction induced by local transfer of Ia-reactive T-cell clones

Epidermal basal cell damage in lichenoid tissue reactions (LTR) is considered to be the result of immunologic injury. In this study, we propose that LTR may be caused by local activation of Ia-reactive T cells. We have established allo-Iak-reactive helper T-cell clones and examined their behavior after adoptive transfer. We show that local transfer of 3 allo-Iak-reactive helper T-cell clones with different cross-reactivities and functions in vitro can cause delayed type hypersensitivity (DTH) reactions in vivo with antigen specificities identical to those demonstrated in vitro. Clone SK.1, when injected into appropriate recipients, caused massive dermal infiltrates of neutrophils and mononuclear cells. The latter were attracted to the epidermis and induced LTR-like basal cell degeneration which peaked at 72 h. Appropriate recipients were those strains of mice whose spleen cells were able to stimulate SK.1 cells to proliferate in vitro. Two other clones, SK.2.18 and SK.2.16, evoked significant DTH responses in their appropriate recipients, but the massive cellular infiltrates induced by either clone never invaded the epidermis or produced an LTR. The degeneration of epidermal cells caused by SK.1 cells did not correlate with the tested functions of this clone in vitro. The finding that only 1 of the 3 allo-Ia-reactive helper T-cell clones induced epidermotropic cellular infiltrates indicates that the infiltrative pattern of leukocytes in skin may depend on the particular T-cell clone that is activated.

An association between HLA DRI and lichen planus

Serological typing for HLA Class II antigens in 72 patients with lichen planus (LP) revealed a highly significant association with HLA DRI and MTI (DQWI). DRI was present in 80% of patients with generalized LP, 54% with localized LP, 56% of patients with drug-induced LP and in 31% of patients with mucosal LP, compared with 25% of normal controls. MTI (DQWI) was found in 83% of the LP group and 62% of the normal controls. These findings strongly suggest a genetic predisposition or susceptibility to the development of generalized LP and perhaps also to drug-induced LP.

Immunologic aspects of acute cutaneous graft-versus-host disease: decreased density and antigen-presenting function of Ia+ Langerhans cells and absent antigen-presenting capacity of Ia+ keratinocytes

Cutaneous graft-versus-host disease (GVHD) provides a unique model for studying the pathogenesis of several important lymphocyte-mediated skin diseases. Morphologic studies have suggested that Ia antigen (Ia)-bearing epidermal Langerhans cells (LC) may be specific targets for destruction in these conditions. Keratinocytes synthesize and express Ia in GVHD and some other lymphocyte-mediated skin disorders; Ia+ keratinocytes, constitutively able to secrete epidermal cell-derived thymocyte activating factor (ETAF)/interleukin 1, may possess antigen-presenting capacity, thus leading to enhanced cutaneous immune responses and disease chronicity. We therefore investigated the fate of Ia+ LC, and the potential antigen-presenting capacity of Ia+ keratinocytes, in a murine model of GVHD. Lethally irradiated C3H/He (H-2k) mice developed acute cutaneous GVHD, and expressed keratinocyte Iak, 8 days after injection of BALB/c (H-2d) bone marrow and spleen cells. Immunofluorescence studies showed a progressive decrease in the density of Ia+ epidermal LC during the evolution of GVHD. This decrease was paralleled by a progressive reduction in the allostimulatory capacity of GVHD epidermal cells (EC) in the allogeneic EC-lymphocyte reaction (ELR). The fall in the density of Ia+ LC, and in EC allostimulatory capacity in both primary and secondary ELRs, was consistently greater in GVHD mice than in mice treated only with x-irradiation. The allostimulatory capacity of GVHD and x-irradiated EC could not be restored by addition of indomethacin or exogenous ETAF to ELR cultures. The decreased allostimulatory capacity was not the result of inhibition of the ELR, since EC from GVHD and x-irradiated mice did not cause suppression when added to control ELR cultures. The capacity of EC to present ovalbumin, purified protein derivative of tuberculin, 2,4,6-trinitrobenzenesulfonic acid coupled to EC, and native cytochrome c (CYTc) to antigen-specific T-cell lines, clones, or hybridomas was reduced in x-irradiated mice and markedly decreased in GVHD mice. The capacity of EC from x-irradiated and GVHD mice to present CYTc fragment 81-104, which does not require further processing or catabolism by accessory cells, was similarly decreased. Taken together, the results indicate that: the function of LC is markedly and progressively impaired in acute GVHD; LC function is also decreased, but to a lesser extent, following x-irradiation alone; and Ia+ keratinocytes from lethally irradiated mice undergoing GVHD do not exhibit antigen-presenting capacity.

Lichenoid dysplasia: a distinct histopathologic entity

We have observed, both in the literature and in practice, that pathologists frequently fail to appreciate subtle dysplastic features in lesions with lichenoid histomorphology. Aside from the obvious diagnostic errors, such oversight can lead to mistaken impressions concerning the natural behavior of relatively benign processes. Accordingly, we have enumerated histologic criteria which define the entity known as "lichenoid dysplasia." Histologic features of lichenoid dysplasia are illustrated and compared with those of other lichenoid lesions, including lichen planus plus nonspecific lichenoid stomatidides. The rationale for and the advantages and objectives of this classification are discussed.

Lichenoid stomatitis associated with lithium carbonate

Lichenoid stomatitis has been reported in the use of a number of drugs. This is a case report of lichenoid stomatitis associated with lithium carbonate. The association between lichenoid stomatitis and lithium carbonate was confirmed by rechallenge in this patient. A number of cutaneous reactions have been reported as adverse effects of lithium therapy. Lichenoid reactions are characterized by an infiltrate of T cells. Lithium has been reported to alter T cell function in vitro.

Familial lichen planus. More frequent than previously suggested?

In a follow-up study of 140 patients with lichen planus we found fifteen patients with a clinically and/or histologically verified family history of the disease, which gives a percentage much higher than that found in previous studies. The reason for this discrepancy might be caused by difficulties in the detection of the disease in family members. Familial lichen planus was found to be different from nonfamilial lichen planus, especially in its effect on young persons and in being a more widespread type with a tendency to result in relapse. The high incidence of familial lichen planus supports the hypothesis that genetic factors are of etiologic importance in lichen planus.

Human epidermal cell-induced generation of alloreactive cytotoxic T-lymphocyte responses against epidermal cells. Requirement for DR-positive Langerhans cells

Human epidermal cells act as stimulators in the mixed-skin cell lymphocyte culture reaction (MSLR). To analyse the generation in MSLR of alloreactive cytotoxic T lymphocytes (CTL) in cell-mediated cytolysis of human epidermal cells. a phenomenon suggested by various observations of skin inflammatory processes in vivo, 18-h 51Cr-release assays against epidermal cells cultivated on collagen-coated plates (epidermal cells autologous to the stimulator cells in MSLR) were conducted after allogenic human MSLR. To analyse the role of human Langerhans cells and related epidermal dendritic cells, which are the only cells expressing the DR-Ia-like (class II) antigens in normal epidermis and in suspensions of normal epidermal cells, MSLR and CTL assays were conducted with, as stimulator cells, suspensions of normal human epidermal cells as controls, and, in parallel, suspensions of epidermal cells after preincubation with anti-class II monoclonal antibody and complement. The generation of alloreactive CTL to epidermal cells occurred only after allogenic MSLR and when targets and stimulator cells were from the same donor; it was abolished when epidermal cell suspensions used in MSLR were depleted in HLA-DR-expressing cells. These findings demonstrate that an epidermal cell-induced generation of cell-mediated cytotoxicity to human epidermal cells may occur in vitro. Langerhans cells and other class II antigen-expressing epidermal cells (dendritic indeterminate cells) are necessary for an optimal in vitro sensitization in MSLR and the subsequent generation of alloreactive CTL towards epidermal cells in man.

Immunohistological skin alterations in allogeneic bone marrow transplantation

Skin biopsies of 26 patients with leukemia and seven patients with aplastic anemia were investigated before and at different stages after allogeneic bone marrow transplantation (BMT) to establish the immunological criteria which distinguish skin alterations during normal reconstitution from dermal lesions mediated by graft-versus-host disease (GvHD). Of the 33 patients studied 27 presented with clinically diagnosed acute and/or chronic GvHD, one patient died of bone marrow rejection. Immunohistological analysis of the respective skin biopsies with selected monoclonal antibodies against human leukocyte antigens (HLA) and differentiation antigens of the lympho-hematopoietic cells revealed low dermal mononuclear cell counts with phenotypically normal constituents in five cases with uncomplicated reconstitution post-grafting. In contrast, increased dermal cellular infiltrates predominantly consisting of Lyt 3+, OKT 8+ T-lymphocytes, as well as of a large number of Ia-like (immune response associated = HLA-D) determinant + monocytes/macrophages were observed in all patients with active acute/chronic GvH reactivity. As sign of activation simultaneous expression of HLA-D region products was also found on a subset of the invading OKT8+ T-lymphocytes. Progression of GvHD was associated with additional surface staining of keratinocytes for Ia-like determinants. Loss of Ia-like determinant+, OKT6+ dentritic epithelial cells in all leukemic patients, as well as in patients with aplastic anemia with or without GvHD suggested damage of Langerhans cells due to the previous radiotherapy and/or specific immunological destruction. In patients with fatal outcome of GvHD prolonged reduction of these dentritic epithelial cells seemed to be indicative of impaired immune reconstitution or bone marrow dysfunction. Thus immunopathological features of skin GvHR may enable early recognition and prognostic evaluation of this disease possibly allowing more effective therapy.

Role of HLA-DR bearing Langerhans and epidermal indeterminate cells in the in vitro generation of alloreactive cytotoxic T cells in man

Human epidermal cells (EC) act as stimulator cells in the mixed-skin cell lymphocyte culture reaction (MSLR). To analyze the role of human epidermal Langerhans cells (LC) and indeterminate cells (IC), which are the only cells expressing the DR-Ia-like antigens in normal epidermis, in the generation of alloreactive cytotoxic T lymphocytes (CTL) in cell-mediated cytolysis, 18-hr 51Cr-release assays against PBL targets (targets autologous to stimulator EC) were conducted after allogeneic human MSLR. MSLR and CTL assays were conducted with, as stimulator cells, suspensions of normal human EC as controls, and EC after: (1) preincubation with anti-HLA-DR or OKT6 (specific for LC in EC suspension) monoclonal antibodies; (2) panning, a monolayer technique used to deplete EC suspensions in OKT6 or DR-positive cells. The generation of alloreactive CTL was found to occur only after allogeneic MSLR and when targets and stimulator cells were from the same donor; it was reduced by EC incubation: cytotoxic activity 26.66 +/- 3.84 (controls); 8.8 +/- 3.6 and 7.7 +/- 3.7 (EC incubated with OKT6 or anti-DR, respectively); it was reduced or abolished when the EC used in MSLR were depleted in OKT6 or DR-positive cells by panning. These findings demonstrate that human LC and IC are necessary for an optimal in vitro sensitization in MSLR and the subsequent in vitro generation of alloreactive CTL in man.

Acute disseminated histiocytosis-X: in situ immunophenotyping with monoclonal antibodies

The proliferating skin cells in a case of acute disseminated histiocytosis-X (Abt-Letterer-Siwe disease) confirmed by electron microscopy, were characterized by a panel of monoclonal antibodies using an immunoperoxidase technique. The "histiocytes" were found to stain with OKT-6 (anti-T6) and anti-HLA-DR antibodies. Unexpectedly, slight staining was also observed with Leu 3a (anti-T4) and OKM-1. A proliferative process of T4, T6, HLA-DR, OKM-1 positive Langerhans' cells has not yet been described and may be specific for histiocytosis-X.

Effects of aromatic retinoid (Ro 109359) on Langerhans' cells in lichen planus

Retinoids are used in the treatment of lichen planus (LP) disease, but their mechanism of action remains unknown. We studied the epidermal Langerhans' cells in four patients with chronic LP, before and after treatment with aromatic retinoids. This study uses a new technique of quantification and exploits two monoclonal antibodies-OKT 6 specific for Langerhans' cells and BL 2 specific for HLA-DR antigens. Our results show an increase in the number of dendritic epidermal cells after treatment with oral retinoids. The number of OKT 6-positive cells is greater than the number of BL 2-positive (HLA-DR) cells before and after treatment.