Characterization of the inflammatory infiltrate and expression of endothelial cell adhesion molecules in lupus erythematosus tumidus

Lupus erythematosus tumidus (LET) is a disease with characteristic clinical and histopathologic features that has not always been considered a subset of cutaneous lupus erythematosus (CLE). Although LET was first mentioned in the literature in 1930, it has rarely been documented, and immunohistochemical studies have never been performed. The aim of the present study was to characterize the inflammatory infiltrate and to analyze the expression of endothelial cell adhesion molecules in skin specimens from patients with LET and to compare the results with those from patients with other variants of CLE, such as discoid lupus erythematosus (DLE) and subacute cutaneous lupus erythematosus (SCLE). Cryostat sections of lesional skin specimens from ten patients with LET demonstrated an infiltrate composed of more than 75% CD4+, CD8+, and HLA-DR+ cells. Interestingly, CD45RO+ cells, in contrast to CD45RA+ cells, were the prevailing inflammatory cell population. Compared with skin specimens from patients with DLE and SCLE, the mean expression of CD4+ and CD8+ cells was higher (but not significantly so) in LET, and no differences were observed with the other three antibodies. Furthermore, in contrast to controls, intercellular adhesion molecule-1, vascular adhesion molecule-1, E-selectin, and P-selectin showed the same expression pattern in skin specimens from patients with DLE, SCLE, and LET. In conclusion, the inflammatory infiltrate of LET primarily consists of CD4+/CD8+ lymphocytes. Furthermore, expression of endothelial cell adhesion molecules was equally upregulated in LET compared with the expression in DLE and SCLE, suggesting a similar immunopathomechanism of these subtypes of CLE.     

Circulating T- and B-cell abnormalities in cutaneous lupus erythematosus

Seven patients with subacute cutaneous lupus erythematosus (SCLE), 11 patients with discoid lupus erythematosus (DLE), and 17 age-, sex-, and race-matched controls were examined for the number of circulating peripheral blood T and B cells, immunoglobulin (Ig) synthesizing cells, and Ig secreting cells. A significant alteration in T-cell subsets was detected only in SCLE patients who manifested a decreased number of OKT8 cells. Circulating B cells were significantly increased only in the SCLE patients. The percentage of Ig synthesizing and secreting cells was significantly increased in both the DLE and the SCLE groups. The somewhat unexpected increase in Ig synthesizing and secreting cells in the DLE patients could not be accounted for by antimalarial treatment or the concurrence of the HLA-DR3 phenotype. There was, however, a weak but significant correlation between the degree of B-cell activation in the DLE patients and the number of American Rheumatism Association criteria for the classification of systemic lupus erythematosus (SLE) possessed by these patients. These data demonstrate that abnormalities in B-cell function similar to those seen in SLE can also be found in a group of lupus erythematosus patients whose clinical disease expression is limited predominantly to the skin.     

Immunopathology of cutaneous human lupus erythematosus defined by murine monoclonal antibodies

Skin biopsy specimens obtained from involved skin from sixteen patients with systemic and discoid lupus erythematosus were studied. Murine monoclonal antibodies with a biotin-avidin-horseradish peroxidase staining system were used. The findings consisted of a marked reduction in the number of epidermal Langerhans cells defined by surface antigens, reduced HLA-DR (Ia-like) antigens on the surface of dermal capillary endothelium, and mononuclear cell infiltrates characterized by a predominance of helper T lymphocytes and an increase in the number of mononuclear phagocytic cells. B lymphocytes were rarely identified. The number of T lymphocytes within the dermis correlated inversely with both the number of HLA-DR-positive epidermal Langerhans cells (p less than 0.01) and the HLA-DR staining of dermal capillary endothelium (p less than 0.01). These findings suggest that a T lymphocyte-mediated immune response associated with a reduction in Langerhans cells and capillary endothelium HLA-DR antigens is involved in the inflammatory process of lupus erythematosus skin.     

Distribution of natural killer cells and lymphocyte subclasses in Jessner's lymphocytic infiltration of the skin and in cutaneous lesions of discoid and systemic lupus erythematosus

We studied the cell infiltrates in biopsies from lymphocytic infiltration of the skin (LIS), with six monoclonal T cell antigen-specific antibodies and compared the reactivity pattern with those in biopsies from discoid and systemic lupus erythematosus skin lesions and allergic contact skin reactions. A newly described antibody (NK₉) recognizing natural killer (NK) cells and activated cytotoxic T lymphocytes was included, and the numbers and activity of circulating NK cells was determined. Immunohistochemical staining revealed that the numbers of NK₉-positive cells were highest in LIS. The distribution of T lymphocytes (OKTii + ve), helper T cells (OKT₄+ ve), suppressor T celts (OKT8 + ve), Langerhans cells (OKT6 + ve) and activated T cells (anti-Tac + ve) in LIS differed from those in DLE, SLE and allergic contact reactions. However, the number of circulating NK cells (large granular lymphocytes) and the NK activity in peripheral blood were normal in LIS. We conclude that in LIS a distinct type of T cell activation occurs; the cause of this remains to be determined.     

Scarring skin lesions of discoid lupus erythematosus are characterized by high numbers of skin-homing cytotoxic lymphocytes associated with strong expression of the type I interferon-induced protein MxA

BACKGROUND: Infiltrating T lymphocytes are considered to play a major pathological role in skin lesions of cutaneous lupus erythematosus (CLE), a cutaneous autoimmune disease of unknown aetiology. Earlier histological studies revealed that the inflammatory infiltrate in CLE skin lesions is predominantly composed of T lymphocytes, with a slight predominance of CD4+ over CD8+ T cells, but failed to explain the development of scarring skin lesions, characteristic for chronic discoid lupus erythematosus (CDLE). Because recent investigations have highlighted the relevance of cytotoxic lymphocytes in autoimmune tissue destruction, we hypothesized that the scarring CDLE lesions might be caused by cytotoxic T lymphocytes. OBJECTIVES: To analyse skin biopsies of 15 patients with CLE [10 female, five male; localized CDLE (lCDLE), n = 5; disseminated CDLE (dCDLE), n = 5, subacute CLE (SCLE), n = 5] and five control biopsies taken from healthy controls and to characterize the inflammatory infiltrate. Methods We used immunohistochemistry, including staining for the cytotoxic molecule granzyme B, the skin-homing molecule cutaneous lymphocyte antigen (CLA) and the protein MxA, which is specifically induced by type I interferons (IFNs). RESULTS: We found a strong coexpression of granzyme B and CLA on lesional lymphocytes of patients with scarring lCDLE and dCDLE, which was significantly enhanced when compared with nonscarring SCLE and healthy controls. The increased expression of granzyme B was closely associated with the lesional expression of the type I IFN-induced protein MxA. CONCLUSIONS: Our results provide evidence that type I IFNs and potentially autoreactive cytotoxic lymphocytes targeting adnexal structures are highly associated with scarring lupus erythematosus lesions and might be responsible for their scarring character.     

Demethylation of promoter regulatory elements contributes to CD70 overexpression in CD4+ T cells from patients with subacute cutaneous lupus erythematosus

Background. Impaired methylation of T‐cell DNA is thought to contribute to the development of systemic lupus erythematosus (SLE). CD70 (TNFSF7) is a B‐cell costimulatory molecule that contributes to excessive B‐cell stimulation in vitro and in vivo. CD70 is overexpressed in CD4+ T cells of patients with SLE, and DNA demethylation occurs in promoter sequences that regulate CD70 expression in SLE CD4+ T cells. However, it is unknown whether the expression and methylation of CD70 in CD4+ T cells are affected in patients with subacute cutaneous lupus erythematosus (SCLE). Objective. To compare CD70 expression levels and the methylation status of the CD70 promoter region in CD4+ T cells from patients with SCLE and healthy controls. Methods. We used real‐time RT‐PCR to compare messenger RNA levels of CD70 and flow cytometry to compare CD70 protein levels in CD4+ T cells from patients with SCLE and healthy controls. Bisulphite sequencing was used to determine the methylation status of the CD70 promoter region. Results. CD70 is overexpressed at the surface of SCLE CD4+ T cells. Demethylation of the CD70 promoter region was seen in CD4+ T cells from patients with SCLE. Conclusions. Demethylation of regulatory elements contributes to CD70 overexpression in CD4+ T cells of patients with SCLE.     

Discoid lupus erythematosus-like lesions in carriers of X-linked chronic granulomatous disease

A questionnaire was sent to 16 carriers of the X-linked cytochrome-b558 negative variant of chronic granulomatous disease (CGD). Of the 15 who answered the questionnaire and from data of one additional case, 70% reported recurrent aphthous stomatitis and 63% had recurrent skin eruptions. Five of the carriers (31%) had clinically discoid lupus erythematosus (DLE), although the histopathology was not typical and the immunofluorescence findings were negative. The infiltrate in the lesional skin of three of these patients was analysed using monoclonal antibodies against CD3, CD4, CD8, CDIa, HLA-DR, CDIc, interdigitating cells, B lymphocytes and cells of the monocyte/macrophage lineage. The immunophenotype of the infiltrating cells resembled that found in discoid lupus erythematosus.     

A candidate gene analysis of three related photosensitivity disorders: cutaneous lupus erythematosus, polymorphic light eruption and actinic prurigo

BACKGROUND: Polymorphic light eruption (PLE) is a common inherited photosensitivity disorder, which may predispose to several related but distinct conditions, including subacute cutaneous lupus erythematosus (SCLE), discoid lupus erythematosus (DLE) and actinic prurigo (AP). OBJECTIVES: To examine specific candidate genes for shared susceptibility alleles between these related phenotypes. METHODS: Eighty-five caucasian patients with annular SCLE or DLE were recruited, in addition to 102 first-degree relatives. The prevalence of PLE in both the patient and relative groups was determined by detailed interview and clinical examination. Eighty-five patients with pure PLE and 59 patients with AP were also recruited. Candidate genes were analysed by typing of single nucleotide polymorphisms of IL10 (-1082 G/A and -819 C/T), FCGR2A (131 R/H), SELE (128 S/R), ICAM1 (241 G/R and 469 E/K), IL1A (+ 4845 G/T), IL1B (-511 C/T and + 3954 C/T), IL1RN (+ 2018 T/C) and TNF (-308 G/A) using polymerase chain reaction (PCR) with sequence-specific primers and 5'-nuclease PCR. RESULTS: A significant association was found between SCLE and the rare TNF -308 A allele when compared with patients with DLE (P = 0.043), PLE (P = 0.001), AP (P < 0.001) and healthy controls (P < 0.001). However, there was strong linkage disequilibrium between TNF -308 A and the HLA A*01, B*08, DRB1*0301 haplotype. A negative association was also found between SCLE and the IL1B + 3954 T allele (P = 0.039), but the significance was lost on correction for multiple testing. CONCLUSIONS: We have demonstrated the association of SCLE with the rare TNF -308 A allele, which may be pathogenic or, alternatively, a marker allele for the extended HLA A*01, B*08, DRB1*0301 haplotype that is associated with a number of autoimmune conditions. Although many of the other loci that we chose failed to demonstrate an association, a candidate gene approach remains the most logical one, and the most likely to yield positive results in the future.     

Abnormal DNA methylation in T cells from patients with subacute cutaneous lupus erythematosus

Background Impaired methylation of T‐cell DNA is thought to contribute to the development of systemic lupus erythematosus. However, it is unknown whether T‐cell hypomethylation is a factor in other, less severe, forms of lupus erythematosus such as subacute cutaneous lupus erythematosus (SCLE). Objectives To investigate global DNA methylation and the expression of genes that regulate methylation in T cells of patients with SCLE. Methods We quantified global methylcytosine levels in CD4+ and CD8+ T cells from 12 patients with SCLE and nine healthy controls. mRNA levels of DNA methyltransferases (DNMTs), methylated CpG binding proteins (MBDs) and CD11a were measured by real‐time quantitative polymerase chain reaction. Results CD4+ T‐cell DNA from patients with SCLE was hypomethylated relative to controls (P = 0·002). DNMT1 and DNMT3a mRNA levels were significantly lower in CD4+ T cells from SCLE patients than in controls (P = 0·027 and P = 0·004, respectively). Relative to controls, MBD1, MBD3 and MBD4 mRNA levels were significantly higher in SCLE CD4+ cells (P < 0·001, P < 0·001 and P = 0·001, respectively), whereas MECP2 and MBD4 mRNA expression were significantly increased in SCLE CD8+ T cells (P = 0·001 and P = 0·001, respectively). DNMT1 expression positively correlated with CD4+ T‐cell DNA methylation within our SCLE patient cohort (r = 0·590, P = 0·044). CD11a mRNA expression was significantly increased in SCLE CD4+ T cells relative to controls (P = 0·044) and negatively correlated with DNA methylation (r = ?0·669, P = 0·049). Conclusions These data suggest that aberrant regulation of DNA methylation in CD4+ T cells is associated with the development of SCLE.     

Upregulation of epidermal surface molecule expression in primary and ultraviolet-induced lesions of lupus erythematosus tumidus

BACKGROUND: Lupus erythematosus tumidus (LET), a photosensitive skin disorder with characteristic clinical and histological features, has not been generally accepted as a subset of cutaneous lupus erythematosus (CLE). OBJECTIVES: To analyse the expression of epidermal surface molecules in skin biopsy specimens from patients with LET and to relate the results to other variants of CLE, such as discoid lupus erythematosus (DLE) and subacute CLE (SCLE). METHODS: In total, 45 patients with different subtypes of CLE were included in the study, and cryostat sections from primary and ultraviolet (UV) A- and UVB-induced skin lesions were investigated using immunohistochemical methods. RESULTS: In contrast to healthy controls, skin lesions of LET showed upregulation of intercellular adhesion molecule-1 (ICAM-1) and histocompatibility class II molecules (HLA-DR), with an expression pattern resembling that seen in DLE and SCLE. Furthermore, staining with a monoclonal antibody against 27E10, a distinct marker for cell activation and differentiation, revealed intense focal or band-like labelling of all epidermal layers independent of the type of lesion. CONCLUSIONS: Expression of epidermal surface molecules such as ICAM-1, HLA-DR and 27E10 is equally upregulated in primary and UV-induced lesions of patients with LET, DLE and SCLE. These results support our recent clinical findings that LET represents a distinct subset of CLE with a similar immunopathomechanism rather than a different disease.     

UVB-induced leucocyte trafficking in the epidermis of photosensitive lupus erythematosus patients: normal depletion of Langerhans cells

BACKGROUND: The pathogenic mechanisms of UV-induced skin lesions of lupus erythematosus (LE) are unknown. In a recent study of pathogenic mechanisms of polymorphic light eruption (PLE), significantly more Langerhans cells (LCs) persisted in the epidermis after UVB overexposure than in healthy individuals. Interestingly, the same phenomenon was observed in one subacute cutaneous lupus erythematosus (SCLE) patient. It could therefore be hypothesized that both photodermatoses share a common pathogenic mechanism of photosensitivity. In the present study, we tested this hypothesis by investigating leucocyte trafficking in the initial phase of cutaneous LE after intense UVB exposure. METHODS: In 22 photosensitive LE patients (12 chronic discoid lupus erythematosus, seven systemic lupus erythematosus and three SCLE) and nine age/sex-matched controls, uninvolved buttock skin was exposed to six minimal erythemal dose (MED) UVB radiation. Subsequently, biopsies were taken after 24, 48 and 72 h, and one control biopsy was taken from unirradiated skin. Skin sections were stained for the presence of LCs, neutrophils and macrophages. Areal percentages of positively stained cells within the epidermis were quantified and compared between the patients and controls. RESULTS: A gradual decrease of epidermal LCs and a gradual increase of epidermal neutrophils and macrophages at several timepoints after six MED irradiation was observed equally in both LE patients and controls. CONCLUSION: Immunohistopathology of irradiated uninvolved skin of photosensitive LE patients did not reveal the same pathologic trafficking of LCs and neutrophils as described for PLE patients. We conclude that different mechanisms are operative in the pathogenesis of PLE and photosensitive LE.     

Immunohistochemical analysis of chronic discoid and subacute cutaneous lupus erythematosus—relation to immunopathological mechanisms

An immunohistochemical analysis of skin biopsies was performed in 18 patients with cutaneous lupus erythematosus (LE), using the alkaline phosphatase and monoclonal anti-alkaline phosphatase method (APAAP). The study group was subdivided on the basis of clinical criteria into 10 patients with chronic discoid LE (CDLE) and eight patients with subacute cutaneous LE (SCLE). Using a panel of monoclonal antibodies the following results were obtained: (i) ICAM-1 was expressed on epidermal keratinocytes, dermal inflammatory cells, and endothelial cells in most biopsies, whereas LFA-1 was confined to the dermis. Attachments between keratinocytes or endothelial cells and activated T lymphocytes via ICAM-1/LFA-1 may be a possible mechanism of target/effector recognition in cutaneous LE. (ii) HLA-DR was expressed on epidermal keratinocytes and cells of the dermal infiltrate, but not on endothelial cells. HLA-DR⁺ cells probably function as antigen-presenting cells, leading to major histocompatibility complex-restricted cellular cytotoxicity in cutaneous LE. (iii) Interleukin 2 receptor expression on dermal inflammatory cells was weak, indicating non-specific activation of T lymphocytes. (iv) The dermal inflammatory cells were T lymphocytes, mainly of the helper/inducer subtype. B lymphocytes were rarely found in the dermis. In general, no significant immunohistochemical differences were found between CDLE and SCLE, suggesting that these variants represent clinical subtypes rather than different pathogenetic entities.     

Plasmacytoid dendritic cells are absent in skin lesions of polymorphic light eruption

BACKGROUND/PURPOSE: Polymorphic light eruption (PLE) is a common photodermatosis of potential autoimmune origin, and an overlap with lupus erythematosus (LE) has been described. Plasmacytoid dendritic cell (PDC)-induced expression of interferon (IFN)-alpha has been found to be present in LE skin lesions and plays a pivotal role in the pathogenesis of LE by promoting autoimmunity. We therefore asked whether PDCs may also be involved in the pathogenesis of PLE and searched for those cells [which can be identified by their high levels of interleukin (IL)-3 receptor alpha chain (CD123), combined with other cell markers such as CD68] in skin lesions. METHODS: Paraffin-embedded biopsy specimens from a total of 27 patients with clinically and histologically confirmed PLE (nine women, mean age 32.7 years, age range 18-43), LE (seven women, four men, CCLE: n=4, SCLE: n=2, lupus tumidus: n=5, mean age 48.5 years, age range 41-65) or psoriasis (four women, three men, mean age 43.3 years, age range 19-54) (as control group) were analyzed by immunohistochemical CD68/CD123 double staining. Quantification of the immunohistochemical staining was performed by visual cell counting of CD68-/CD123+, CD68+/123-, and CD68+/CD123+ cells separately in the epidermis and dermis of the samples in at least 10 random fields per sample at x 400 microscopic magnification by two of the investigators in a blinded fashion. RESULTS: Microscopic examination of the immunohistochemically stained sections revealed that CD68+/CD123+ cells were present in most specimens obtained from LE [10/11 (91%)] and psoriasis [6/7 (86%)] patients but not at all in those obtained from PLE patients. Quantification and statistical analysis of the dermal infiltrate revealed that CD68+/CD123+ cells were present at a mean+/-SEM field density of 5.6+/-1.3 in LE, 1.6+/-0.6 in psoriasis but totally absent in PLE (P=0.0010 vs. LE, P=0.0135 vs. psoriasis by an unpaired Student's t-test). CONCLUSION: The results confirm the potential significance of PDCs in LE and psoriasis, however the absence of PDCs in PLE contradicts the hypothesis that these cells might play a role in the latter disease.     

A protective effect of glutathione-S-transferase GSTP1*Val(105) against polymorphic light eruption

Polymorphic light eruption (PLE) is a common skin disease, susceptibility to which is genetically determined. The prevalence of PLE is significantly increased in patients with lupus erythematosus (LE) including subacute cutaneous lupus erythematosus (SCLE) and discoid lupus erythematosus (DLE), which may reflect a common genetic background. Experimental evidence supports a role for reactive oxygen species (ROS) in the pathogenesis of PLE, and the family of glutathione-S-transferase (GST) enzymes exerts a critical physiological role in cellular protection against this oxidative damage. Our aim was to look for association between the functional GST gene polymorphisms and PLE, SCLE, and DLE in a case-control study. The carrier frequency of GSTP1 Val(105) in subjects with PLE was 40%, significantly lower than the carrier frequency in controls (54%, P=0.019), although significance was lost on correction for multiple testing. However, the carrier frequency of the GSTP1 Val(105) allele in combined cutaneous LE (SCLE and DLE) patients with PLE was 42%, significantly lower than in those without PLE (72%), which did survive correction (corrected P=0.043). We have identified evidence supporting a protective GSTP1 allele, the first genetic association to be reported for PLE. This supports a role for ROS in the pathogenesis of PLE and may provide a therapeutic target for future treatment of this common, often disabling, condition.     

Macrophage marker 27E10 on human keratinocytes helps to differentiate discoid lupus erythematosus and Jessner's lymphocytic infiltration of the skin

Chronic inflammatory discoid lupus erythematosus (DLE) and Jessner's lymphocytic infiltration of the skin (LIS) are both characterized by dermal infiltrates of activated T lymphocytes. However, an inflammatory involvement of the epidermis is only found in DLE. We therefore compared the phenotypic properties of the keratinocytes using immunohistochemical stainings of biopsies from typical DLE and LIS. Keratinocytes failed to express HLA-DR in LIS and surprisingly also in DLE. The adhesion molecule ICAM-1 was only expressed in DLE, with focal staining of the basal keratinocytes in close association with intraepidermal lymphocytes. The monoclonal antibody 27E10, a distinct marker for macrophage activation and differentiation, revealed a strong band-like labelling of the suprabasal and upper keratinocytes in DLE. In contrast, no epidermal expression of this biologically active heterodimer of the calcium-binding proteins MRP-8 and MRP-14 was found in LIS. The staining patterns provide a new method to differentiate DLE and LIS by immunohistochemistry and suggest a distinct type of keratinocyte activation and differentiation in DLE which would in turn mediate epidermal T cell infiltration.     

In situ characterization of cellular infiltrates in lupus vulgaris indicates lesional T-cell activation.

Skin biopsy specimens from nine patients with lupus vulgaris were examined in situ by means of monoclonal antibodies directed against phenotypes of lymphocyte subsets, Langerhans cells, HLA-DR antigens, and interleukin 2 receptor. The epidermis showed prominent changes, including intense expression of HLA-DR on keratinocytes, increase in epidermal cell layers, moderate to high Langerhans cell hyperplasia, and infiltration by CD3+ pan-T cells as well as CD8+ (cytotoxic/suppressor) and CD4+ (helper/inducer) T cells. The predominant lymphocyte in the dermal granulomas was the activated CD3+ T cell, expressing major histocompatibility complex class II antigens and interleukin 2 receptor. CD4+ and CD8+ cells were randomly distributed among the epithelioid cells, which showed intense staining for major histocompatibility complex class II antigens. In all except two patients, the CD4+ population was greater than that of the CD8+ cells. CD1+ Langerhans cells were scattered in moderate numbers in the dermal granulomas. Acid-fast bacilli were conspicuously absent in the biopsy specimens. These features suggest that T-cell activation and Langerhans cell hyperplasia are prominent features of dermal tuberculosis.     

The circulating lymphocyte profiles in patients with discoid lupus erythematosus and systemic lupus erythematosus suggest a pathogenetic relationship

BACKGROUND: Discoid lupus erythematosus (DLE) and systemic lupus erythematosus (SLE) are chronic inflammatory diseases of unknown aetiology; the relationship of DLE with SLE has been a subject of debate for many years. OBJECTIVES; To find evidence for systemic immune activation in DLE by analysis of the immunophenotypic profiles of circulating lymphocytes, and to compare these changes with those in patients with SLE. METHODS: The immunophenotypic profile of peripheral blood lymphocyte subsets from 23 DLE patients without clinical or laboratory evidence of systemic disease, 25 SLE patients and 38 healthy donors was characterized by two-colour immunofluorescence flow cytometry analysis. None of the patients was receiving corticosteroid or immunosuppressive treatment. RESULTS: Patients with DLE had increased numbers of circulating HLA-DR+ CD3+ T cells and HLA-DR+ CD4+ T cells, indicating systemic T-cell activation, and an expansion of CD5+ CD19+ B cells. Decreased numbers of T-cell subsets expressing the differentiation markers CD11b and CD16/56, and of CD16/56+ natural killer cells were also found. In SLE, the changes were similar but more pronounced. In addition, a profound CD4+ T-cell lymphopenia and an increase of HLA-DR+ CD8+ T cells were found only in SLE. CONCLUSIONS: Our data provide evidence for systemic activation of the cellular immune system in patients with purely cutaneous DLE. Similarities in the lymphocyte immunophenotypic profiles in patients with DLE compared with SLE suggest that there are common immunopathological processes in these two conditions.     

The phenotypic profile of dermatomyositis and lupus erythematosus: a comparative analysis

Background: The mechanisms which regulate cutaneous inflammation in the setting of collagen vascular disease have been a topic of recent interest; emphasis has been placed on type I interferon‐associated recruitment of CXCR3+ lymphocytes in dermatomyositis (DM). Methods: On a total of 42 biopsies from patients with DM, systemic lupus erythematosus (SLE), discoid lupus erythematosus (DLE) and subacute cutaneous lupus erythematosus (SCLE) comprehensive phenotypic studies were performed to explore the practical value of phenotypic analysis in the subclassification of lesions of collagen vascular disease. Results: The infiltrate in DM was of mild intensity compared to lupus erythematosus (LE). The dominant mononuclear cell in DM exhibited a CD4/CXCR3‐positive phenotype while biopsies of SLE typically showed a dearth of CXCR3‐positive cells. CD8 and CD20 lymphocytes were greatest in SLE and DLE, respectively. CD123 plasmacytoid dendritic cells, seen in most cases, were most frequent in cases of SCLE; CD83 expression was minimal. Endothelial MXA expression was a characteristic feature of DM. CD123 and MXA expression within inflammatory cells and keratinocytes was most conspicuous in areas of interface injury. Cutaneous lymphocyte antigen (CLA) expression was diminished in the dermal infiltrate in most cases of DM and LE. T regulatory cells never exceeded 15% of the infiltrate and were the least in the setting of DM and LE. Conclusions: An interferon‐α‐inducible cytokine milieu is common in SLE, DLE, SCLE and DM. In addition, there are phenotypic differences as alluded to above that may be of some practical value in separating these distinctive subsets. Features not previously emphasized such as MXA endothelial cell staining in DM and the lack of staining for CD83 and CLA in lesions of collagen vascular disease may be of diagnostic value. Magro CM, Segal JP, Crowson AN, Chadwick P. The phenotypic profile of dermatomyositis and lupus erythematosus: a comparative analysis.     

Annular Erythema

Abstract: Annular erythema developed in 22 patients with Sjögren syndrome. Clinically, the annular erythema was subdivided into three forms: Sweet disease-like annular erythema with an elevated border (14 cases): subacute cutaneous lupus erythematosus (SCLE)-like marginally scaled erythema (5 cases): and papular erythema (3 cases). Histopathologically, features commonly seen in annular erythema are deep perivascular and/or periappendageal infiltration of the lymphocytes with an admixture of neutrophils or plasma cells and less frequent epidermal changes suggestive of cutaneous lupus erythematosus. Immunoglobulin or complement deposition along the dermoepidermal junction of lesional skin was observed in 8 of 18 cases, and most of the dermal infiltrates consisted of CD4(+), 4B4(+) cells. The appearance of anti-SS-A(Ro) (100%) and anti-SS-B(La) (77%) was significantly higher in patients with annular erythema. These results suggest that patients with Sjögren syndrome might have a distinct annular erythematous lesion that is both clinically and histopathologically different from SCLE, although dose immunologic abnormalities exist in these two diseases.     

Identification of granzyme B‐expressing CD‐8‐positive T cells in lymphocytic inflammatory infiltrate in cutaneous lupus erythematosus and in dermatomyositis

Background. Lupus erythematosus (LE) and dermatomyositis (DM) are interface dermatitis, histologically characterized by formation of colloid bodies and a CD4+ CD8+ lymphocyte infiltrate. Colloid bodies are examples of intraepidermal apoptosis. Granzyme (Gr)B, synthesized by activated cytotoxic lymphocytes, is a serine protease able to prime apoptosis. GrB+ lymphocytes have been previously found in infiltrates in skin lesions from other types of interface dermatitis. Aim. To evaluate, on histological skin specimens from patients with LE and DM, GrB expression as a mediator of keratinocyte apoptosis in lymphocyte infiltrate. Methods. In total, 22 patients with cutaneous LE [9 with discoid lupus erythematosus (DLE), 9 with subacute lupus erythematosus (SCLE) and 4 with systemic lupus erythematosus (SLE)] and 20 patients with DM were studied. Skin specimens underwent immunohistochemical staining with antibodies to CD3, CD4, CD8 and GrB. Results. Immunohistochemical study with GrB was positive in 17 of the 22 patients with LE but only 2 of the 20 patients with DM. In LE, in systemic and subacute forms of LE, the median obtained was < 10 (+) whereas in the chronic forms, the median was 10–50% (++). Patients with DM were negative for GrB. Conclusions. In LE, a correlation between GrB+ lymphocyte and the presence of DLE form was found, but in DM, GrB is poorly expressed. GrB labels a subpopulation of effector cells involved in ongoing cytotoxic action and should be considered as a specific marker showing the extent of the direct local cytotoxic damage. GrB could play a role in the induction of skin apoptosis mechanisms in LE.