Phototesting in lupus erythematosus

Development of bullous systemic lupus erythematosus in patient treated with NB-UVB: A case report and comprehensive review of the literature

Key Clinical Message

The use of phototherapy is highly effective in treating various skin diseases. In this study, the aim is to present vesicular and blister lesions in patients treated with UVB for psoriasis. It is advisable to consider the possibility of BSLE in cases of vesiculobullous lesions following phototherapy, along with other potential diagnoses.

Abstract

Bullous systemic lupus erythematosus (BSLE) is a rare form of cutaneous lupus erythematosus that presents as vesicles and blisters on various parts of the body. The pathological appearance of these lesions often shows subepidermal vesicles with deposits of IgG, IgM, IgA, and complement C3 in granular or linear forms under direct immunofluorescence (DIF) examination. Clinical studies demonstrate the effectiveness of phototherapy in treating various skin conditions. While several studies suggest a correlation between phototherapy and the development of vesiculobullous lesions, most of these reports are related to bullous pemphigoid, with limited research on the occurrence of BSLE following phototherapy. In this case report, vesicular and blistering lesions in a 70-year-old man undergoing UVB treatment for psoriasis are described. Pathological examination confirmed the diagnosis of bullous systemic lupus erythematosus, and the patient experienced significant improvement after treatment with dapsone tablets. A literature review was conducted on the development of vesiculobullous lesions after phototherapy, comparing different approaches presented in previous studies. Our conclusion highlights the importance of considering BSLE as a possible diagnosis in cases of vesiculobullous lesions post-phototherapy, alongside other potential conditions.

Review on photoprotection: a clinician’s guide to the ingredients, characteristics, adverse effects, and disease-specific benefits of chemical and physical sunscreen compounds

Photoprotection is a critical health prevention strategy to reduce the deleterious effects of ultraviolet radiation (UVR) and visible light (VL). Methods of photoprotection are reviewed in this paper, with an emphasis on sunscreen. The most appropriate sunscreen formulation for personal use depends on several factors. Active sunscreen ingredients vary in their protective effect over the UVR and VL spectrum. There are dermatologic diseases that cause photosensitivity or that are aggravated by a particular action spectrum. In these situations, sunscreen suggestions can address the specific concern. Sunscreen does not represent a single entity. Appropriate personalized sunscreen selection is critical to improve compliance and clinical outcomes. Health care providers can facilitate informed product selection with awareness of evolving sunscreen formulations and counseling patients on appropriate use. This review aims to summarize different forms of photoprotection, discuss absorption of sunscreen ingredients, possible adverse effects, and disease-specific preferences for chemical, physical or oral agents that may decrease UVR and VL harmful effects.

Mechanisms of Photosensitivity in Autoimmunity

Aberrant responses to UV light frequently lead to the formation of skin lesions and the activation of systemic inflammation in some autoimmune diseases, especially systemic lupus erythematosus. Whereas the effects of UV light on the skin have been studied for decades, only recently have some of the mechanisms that contribute to abnormal responses to UV light in patients with autoimmune diseases been uncovered. This review will discuss the biology of UV in the epidermis and discuss the abnormal epidermal and inflammatory mechanisms that contribute to photosensitivity. Further research is required to fully understand how to normalize UV-mediated inflammation in patients with autoimmune diseases.

Cutaneous lupus erythematosus: A review of the literature

Knowledge with regard to the pathogenesis of lupus erythematosus has progressed rapidly over the past decade, and with it has come promising new agents for the treatment of cutaneous lupus erythematous (CLE). Classification of CLE is performed using clinical features and histopathologic findings, and is crucial for determining prognosis and choosing therapeutic options. Preventative therapy is critical in achieving optimal disease control, and patients should be counseled on sun-safe behavior and smoking cessation. First-line therapy includes topical corticosteroids and calcineurin inhibitors, with antimalarial therapy. Traditionally, refractory disease was treated with oral retinoids, dapsone, and other oral immunosuppressive drugs, but new therapies are emerging with improved side effect profiles and efficacy. Biologic agents, such as belimumab and ustekinumab, have been promising in case studies but will require larger trials to establish their role in routine therapy. Other novel therapies that have been trialed successfully include spleen tyrosine kinase inhibitors and fumaric acid esters. Finally, new evidence has been published recently that describes safer dosing regimens in thalidomide and lenalidomide, both effective medications for CLE. Given the chronic disease course of CLE, long-term treatment-related side effects must be minimized, and the introduction of new steroid-sparing agents is encouraging in this regard.

Ultraviolet light induces increased T cell activation in lupus-prone mice via type I IFN-dependent inhibition of T regulatory cells

Ultraviolet (UV) light is a known trigger of skin and possibly systemic inflammation in systemic lupus erythematosus (SLE) patients. Although type I interferons (IFN) are upregulated in SLE skin after UV exposure, the mechanisms to explain increased UVB-induced inflammation remain unclear. This paper compares the role of type I IFNs in regulating immune cell activation between wild-type and lupus-prone mice following UVB exposure. 10-week old female lupus-prone (NZM2328), wild-type (BALB/c) and iNZM mice (lack a functional type I IFN receptor on NZM2328 background) were treated on their dorsal skin with 100 mJ/cm² of UVB for 5 consecutive days. Following UVB treatment, draining lymph node cell populations were characterized via flow cytometry and suppression assays; treated skin was examined for changes in expression of type I IFN genes. Only NZM2328 mice showed an increase in T cell numbers and activation 2 weeks post UVB exposure. This was preceded by a significant increase in UVB-induced type I IFN expression in NZM2328 mice compared to BALB/c mice. Following UVB exposure, both BALB/c and iNZM mice demonstrated an increase in functional T regulatory (T_Reg) cells; however, this was not seen in NZM2328 mice. These data suggest a skewed UVB-mediated T cell response in lupus-prone mice where activation of T cells is enhanced secondary to a type I IFN-dependent suppression of T_Reg cells. Thus, we propose type I IFNs are important for UVB-induced inflammation in lupus-prone mice and may be an effective target for prevention of UVB-mediated flares.

Standardized Ultraviolet-A Exposure Provokes Skin Reaction in Systemic Lupus Erythematosus

The immediate, 1 day and 14 days skin reaction was determined in 23 female SLE patients and 23 age-matched controls after standardized exposure to ultraviolet light of the UV-A wavelengths (320-440 nm). Eighteen of the patients and 12 of the controls were photosensitive by history. Eight separate sites on the buttocks were exposed to UV-A light, four sites at doses between 42 and 252 kJ/m2 and four sites with longpass filters (320, 345, 360 and 375 nm). The reactions on test sites were graded by two independent observers unaware of given doses or filter location. All patients and controls reacted with immediate erythema irrespectively of the presence or absence of photosensitivity. After 1 day, 39% of controls and 78% of patients had erythema and the reactions were more pronounced to longwave UV-A light (>320 nm) in the patients (P < 0.001). After 14 days, six patients, but no control, had persistent erythema (P = 0.04). Interestingly, three of the four patients without anamnestic photosensitivity did not react on days 1 or 14, while the pattern seen in the controls on day 1 was totally unpredictable with regard to reported photosensitivity. These findings strongly suggest that a considerable proportion of SLE patients show pathological skin reactions to physiological doses of longwave UV-A and not only the far more studied shortwave UV-B (290-320 nm). The responsible chromatophore for the UV-A reaction is not known.

In silico Analyses of Skin and Peripheral Blood Transcriptional Data in Cutaneous Lupus Reveals CCR2-A Novel Potential Therapeutic Target

Cutaneous lesions feature prominently in lupus erythematosus (LE). Yet lupus and its cutaneous manifestations exhibit extraordinary clinical heterogeneity, making it imperative to stratify patients with varying organ involvement based on molecular criteria that may be of clinical value. We conducted several in silico bioinformatics-based analyses integrating chronic cutaneous lupus erythematosus (CCLE)-skin and blood expression profiles to provide novel insights into disease mechanisms and potential future therapy. In addition to substantiating well-known prominent apoptosis and interferon related response in both tissue environments, the overrepresentation of GO categories in the datasets, in the context of existing literature, led us to model a “disease road-map” demonstrating a coordinated orchestration of the autoimmune response in CCLE reflected in three phases: (1) initiation, (2) amplification, and (3) target damage in skin. Within this framework, we undertook in silico interactome analyses to identify significantly “over-connected” genes that are potential key functional players in the metabolic reprogramming associated with skin pathology in CCLE. Furthermore, overlapping and distinct transcriptional “hot spots” within CCLE skin and blood expression profiles mapping to specified chromosomal locations offer selected targets for identifying disease-risk genes. Lastly, we used a novel in silico approach to prioritize the receptor protein CCR2, whose expression level in CCLE tissues was validated by qPCR analysis, and suggest it as a drug target for use in future potential CCLE therapy.

Human and Murine Evidence for Mechanisms Driving Autoimmune Photosensitivity

Ultraviolet (UV) light is an important environmental trigger for systemic lupus erythematosus (SLE) patients, yet the mechanisms by which UV light impacts disease are not fully known. This review covers evidence in both human and murine systems for the impacts of UV light on DNA damage, apoptosis, autoantigen exposure, cytokine production, inflammatory cell recruitment, and systemic flare induction. In addition, the role of the circadian clock is discussed. Evidence is compared in healthy individuals and SLE patients as well as in wild-type and lupus-prone mice. Further research is needed into the effects of UV light on cutaneous and systemic immune responses to understand how to prevent UV-light mediated lupus flares.

The Cutaneous Spectrum of Lupus Erythematosus

Systemic lupus erythematosus is a complex autoimmune disease with a wide spectrum of clinical and immunopathological features. Cutaneous and articular manifestations are the most common signs in patients with systemic lupus erythematosus. We here review the pathogenesis and the new classification of cutaneous lupus erythemathosus with a discussion of the significance of the various cutaneous signs. The lesions are classified according to the level of the cellular infiltrate and tissue damage in the epidermis, dermis, and/or subcutis. Furthermore, cutaneous lesions pointing to the presence of a thrombotic vasculopathy and those due to a distinct inflammatory, neutrophilic-mediated reaction pattern are highlighted. Particular attention will be given in describing the histology of skin manifestation. Treatment options for cutaneous lupus erythemathosus have increased with the introduction of new biological therapies. However, the majority of the patients still benefit from antimalarials, which remain the cornerstone of treatment. The evaluation and management of cutaneous lupus erythemathosus patients depend on the clinical findings and associated symptoms.

Photosensitivity, apoptosis, and cytokines in the pathogenesis of lupus erythematosus: a critical review

The underlying pathomechanisms of lupus erythematosus (LE), a multifactorial autoimmune disease, remain elusive. Due to the clinical evidence demonstrating a clear relationship between ultraviolet (UV) light exposure and skin lesions of LE, photosensitivity has been proven to be an important factor in the pathogenesis of the disease. Standardised photoprovocation with UVA and UVB irradiation has been shown to be a reliable model for evaluating photosensitivity in patients with cutaneous LE (CLE) and analysing the underlying medical conditions of the disease. In this respect, UV irradiation can cause aberrant induction of apoptosis in keratinocytes and contribute to the appearance of excessive apoptotic cells in the skin of CLE patients. Moreover, apoptotic cells that cannot be cleared by phagocytes may undergo secondary necrosis and release proinflammatory compounds and potential autoantigens, which may contribute to the inflammatory micromilieu that leads to formation of skin lesions in the disease. In addition to UV-mediated induction of apoptosis, the molecular and cellular factors that may cause the abnormal long-lasting photoreactivity in CLE include mediators of inflammation, such as cytokines and chemokines. In particular, interferons (IFNs) are important players in the early activation of the immune system and have a specific role in the immunological interface between the innate and the adaptive immune system. The fact that treatment with recombinant type I IFNs (α and β) can induce not only systemic organ manifestations but also LE-like skin lesions provides additional evidence for a pathogenetic role of these IFNs in the disease.

Characterization of clinical photosensitivity in cutaneous lupus erythematosus

BACKGROUND

Photosensitivity (PS) in lupus erythematosus (LE) is frequently determined by patient report.

OBJECTIVE

We sought to characterize self-reported PS in cutaneous LE (CLE).

METHODS

The PS survey was used to classify subject responses into 5 phenotypes: direct sun-induced CLE flare (directCLE); general exacerbation of CLE (genCLE); polymorphic light eruption-like reactions (genSkin); general pruritus/paresthesias (genRxn); and sun-induced systemic symptoms (genSys). In all, 91 subjects with CLE alone or with CLE and systemic LE were interviewed.

RESULTS

In all, 81% ascribed to 1 or more PS phenotypes. CLE-specific reactions (direct sun-induced CLE flare or general exacerbation of CLE) were reported by 86% of photosensitive subjects. Higher CLE disease activity (measured by CLE Disease Area and Severity Index activity scores) was suggestive of direct sun-induced CLE flare reactions (P = .09). In all, 60% of photosensitive subjects described CLE-nonspecific reactions: polymorphic light eruption-like rash and general pruritus/paresthesias. These phenotypes often co-occurred with CLE-specific reactions and were predicted by more systemic disease activity as measured by Physicians Global Assessment (PGA) scores in regression analyses (genSkin, P = .02) and (genRxn, P = .05). In all, 36% of subjects reported systemic reactions and higher PGA scores were predictive of the sun-induced systemic symptoms phenotype (P = .02); a diagnosis of systemic LE was not (P = .14).

LIMITATIONS

PS was inferred from patient report and not directly observed.

CONCLUSIONS

Characterization of self-reported PS in LE reveals that patients experience combinations of CLE-specific, CLE-nonspecific, and systemic reactions to sunlight. Sun-induced CLE flares are associated with more active CLE disease. Polymorphic light eruption-like, generalized pruritus/paresthesias, and systemic reactions are associated with more active systemic disease. Recognition of PS phenotypes will permit improved definitions of clinical PS and allow for more precise investigation into its pathophysiology.

Prevalence of self-report photosensitivity in cutaneous lupus erythematosus

BACKGROUND

Little is known about the prevalence of self-reported photosensitivity (PS) and its effects on quality of life in a US cutaneous lupus population.

OBJECTIVE

We sought to determine the prevalence of self-reported PS among a cutaneous lupus population and to examine its impact on quality of life.

METHODS

A total of 169 patients with lupus were interviewed about PS symptoms and completed the modified Skindex-29+3, a quality-of-life survey. A complete skin examination was conducted and the Cutaneous Lupus Erythematosus Disease Area and Severity Index was completed.

RESULTS

In all, 68% of patients reported some symptoms of PS. The PS group (those who reported a history of and current PS) scored worse on PS-related items of the modified Skindex-29+3 and had higher cutaneous disease activity as determined by the Cutaneous Lupus Erythematosus Disease Area and Severity Index. Patients with PS had worse symptoms and emotions and experienced significant functional impairments compared with patients who had cutaneous lupus without PS.

LIMITATIONS

This study was done at a single referral center.

CONCLUSIONS

Self-reported PS is very common among patients with cutaneous lupus and is associated with significant impairments related to symptoms, emotions, and daily functioning.

Photosensitivity, phototesting, and photoprotection in cutaneous lupus erythematosus

Cutaneous lupus erythematosus (CLE) is a heterogeneous autoimmune disease involving well-defined skin lesions that can be categorized as acute CLE (ACLE), subacute CLE (SCLE), chronic CLE (CCLE), or intermittent CLE (ICLE). It is commonly accepted that ultraviolet (UV) exposure can induce and exacerbate skin lesions in patients with certain subtypes of CLE. Phototesting with UVA and UVB irradiation using a standardized protocol has proven to be a reliable model to study photosensitivity in CLE and to analyse the underlying pathomechanisms of the disease. In addition to UV-mediated induction of apoptosis, the molecular and cellular factors that may underlie the abnormal long-lasting photoreactivity in CLE include mediators of inflammation such as cytokines and chemokines, inducible nitric oxide (NO) synthase (iNOS), and cellular adhesion molecules. The photosensitivity associated with CLE requires education of the patient about avoidance of excessive sun exposure, continuous photoprotection through physical measures such as protective clothing, and daily application of broad-spectrum sunscreens. Novel approaches to UV-protection, such as alpha-MSH or thymidine dinucleotides, might also have an impact on photosensitivity in patients with CLE. In this review, we summarize the current knowledge about photosensitivity in patients with CLE, including an overview of standardized phototesting procedures, possible molecular pathomechanisms, and photoprotection. Lupus (2010) 19, 1036—1046.

Ultraviolet light and cutaneous lupus

Exposure to ultraviolet (UV) light is one of the major factors known to trigger cutaneous disease activity in (systemic) lupus erythematosus patients. UV light, UVB in particular, is a potent inducer of apoptosis. Currently, disturbed clearance of apoptotic cells is one of the concepts explaining the development of inflammation in lupus patients. We review the role of apoptotic cells and autoantibodies in the pathogenesis of UVB induced skin lesions.

Is disturbed clearance of apoptotic keratinocytes responsible for UVB-induced inflammatory skin lesions in systemic lupus erythematosus?

Apoptotic cells are thought to play an essential role in the pathogenesis of systemic lupus erythematosus (SLE). We hypothesise that delayed or altered clearance of apoptotic cells after UV irradiation will lead to inflammation in the skin of SLE patients. Fifteen SLE patients and 13 controls were irradiated with two minimal erythemal doses (MEDs) of ultraviolet B light (UVB). Subsequently, skin biopsies were analysed (immuno)histologically, over 10 days, for numbers of apoptotic cells, T cells, macrophages, and deposition of immunoglobulin and complement. Additionally, to compare results with cutaneous lesions of SLE patients, 20 biopsies of lupus erythematosus (LE) skin lesions were analysed morphologically for apoptotic cells and infiltrate. Clearance rate of apoptotic cells after irradiation did not differ between patients and controls. Influx of macrophages in dermal and epidermal layers was significantly increased in patients compared with controls. Five out of 15 patients developed a dermal infiltrate that was associated with increased epidermal influx of T cells and macrophages but not with numbers of apoptotic cells or epidermal deposition of immunoglobulins. Macrophages were ingesting multiple apoptotic bodies. Inflammatory lesions in these patients were localised near accumulations of apoptotic keratinocytes similar as was seen in the majority of LE skin lesions. In vivo clearance rate of apoptotic cells is comparable between SLE patients and controls. However, the presence of inflammatory lesions in the vicinity of apoptotic cells, as observed both in UVB-induced and in LE skin lesions in SLE patients, suggests that these lesions result from an inflammatory clearance of apoptotic cells.

Failure of physiologic doses of pure UVA or UVB to induce lesions in photosensitive cutaneous lupus erythematosus: implications for phototesting

BACKGROUND

Phototesting studies in cutaneous lupus erythematosus have yielded variable results, with most trials reporting photo-induction of lesions by both UVA and UVB in substantial numbers of patients.

OBJECTIVES

To determine the minimal erythema dose in patients with subacute cutaneous lupus erythematosus (SCLE) and controls.

PATIENTS/METHODS

We phototested nine patients with SCLE and 14 skin type-matched controls, using repetitive dosing of UVA1 and UVB, but with filters that removed most of the shorter UVC and longer infrared and visible light. In addition, DNA was isolated from anticoagulated blood to genotype the TNF-alpha 308 region in each patient and control.

RESULTS

We were unable to demonstrate a difference in minimal erythema dose (MED) between patients and controls, or any correlation of MED with either TNF genotype or systemic drug therapy for SCLE. In addition, no SCLE skin lesions were induced in the nine patients with either UVA or UVB, and one patient cleared a skin lesion after low-dose UVA1 irradiation.

CONCLUSIONS

The potential role of wavelengths outside the UVA and UVB range in the photo-induction of cutaneous lupus skin lesions needs to be investigated, and there is a need to standardize phototesting equipment and procedures for patients with cutaneous lupus erythematous.

Skin sensitivity to UVB irradiation in systemic lupus erythematosus is not related to the level of apoptosis induction in keratinocytes

OBJECTIVES

Accumulation of apoptotic cells has been suggested to be involved in the pathogenesis of systemic lupus erythematosus (SLE). As sunlight exposure is one of the factors that can trigger disease activity, we hypothesized that UV light may induce increased numbers of apoptotic cells in SLE.

METHODS

Fourteen SLE patients and 16 controls were irradiated with UVB to determine their minimal erythemal dose (MED). Subsequently, skin was irradiated with 1 MED and 2 MED, respectively, and after 24 h skin biopsies were analysed immunohistologically for the number of apoptotic cells and presence of pyknotic nuclear debris.

RESULTS

MED was significantly decreased in SLE patients and the presence of decreased MED was associated with a history of butterfly rash. Decreased MED was not related to other skin-related ACR criteria or to autoantibody specificities. No differences were detected in the numbers of apoptotic keratinocytes between patients and controls or in the amount of pyknotic nuclear debris following 1 and 2 MED irradiation, respectively. Absolute UVB doses were correlated with the number of apoptotic keratinocytes; dose-responses did not differ significantly between patients and controls.

CONCLUSIONS

Increased sensitivity of SLE patients to UVB, although associated with a history of malar rash, is not related to increased induction of apoptosis or increased levels of secondary necrosis in the skin. Thus, compared with controls, UVB-induced apoptosis is not increased in SLE patients under physiological conditions.

Ultraviolet radiation-induced injury, chemokines, and leukocyte recruitment: An amplification cycle triggering cutaneous lupus erythematosus

OBJECTIVE

To investigate the activation and recruitment pathways of relevant leukocyte subsets during the initiation and amplification of cutaneous lupus erythematosus (LE).

METHODS

Quantitative real-time polymerase chain reaction was used to perform a comprehensive analysis of all known chemokines and their receptors in cutaneous LE lesions, and the cellular origin of these chemokines and receptors was determined using immunohistochemistry. Furthermore, cytokine- and ultraviolet (UV) light-mediated activation pathways of relevant chemokines were investigated in vitro and in vivo.

RESULTS

In the present study, we identified the CXCR3 ligands CXCL9 (interferon-gamma [IFNgamma]-induced monokine), CXCL10 (IFNgamma-inducible protein 10), and CXCL11 (IFN-inducible T cell alpha chemoattractant) as being the most abundantly expressed chemokine family members in cutaneous LE. Expression of these ligands corresponded with the presence of a marked inflammatory infiltrate consisting of mainly CXCR3-expressing cells, including skin-homing lymphocytes and blood dendritic cell antigen 2-positive plasmacytoid dendritic cells (PDCs). Within cutaneous LE lesions, PDCs accumulated within the dermis and were activated to produce type I IFN, as detected by the expression of the IFNalpha-inducible genes IRF7 and MxA. IFNalpha, in turn, was a potent and rapid inducer of CXCR3 ligands in cellular constituents of the skin. Furthermore, we demonstrated that the inflammatory CXCR3 ligands cooperate with the homeostatic chemokine CXCL12 (stromal cell-derived factor 1) during the recruitment of pathogenically relevant leukocyte subsets. Moreover, we showed that UVB irradiation induces the release of CCL27 (cutaneous T cell-attracting chemokine) from epidermal compartments into dermal compartments and up-regulates the expression of a distinct set of chemokines in keratinocytes.

CONCLUSION

Taken together, our data suggest an amplification cycle in which UV light-induced injury induces apoptosis, necrosis, and chemokine production. These mechanisms, in turn, mediate the recruitment and activation of autoimmune T cells and IFNalpha-producing PDCs, which subsequently release more effector cytokines, thus amplifying chemokine production and leukocyte recruitment, finally leading to the development of a cutaneous LE phenotype.

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.

Immunopathology of vesicular cutaneous lupus erythematosus in the rough collie and Shetland sheepdog: a canine homologue of subacute cutaneous lupus erythematosus in humans

Clinical and histological features of an erosive disease in the rough collie and Shetland sheepdog are most consistent with a vesicular variant of cutaneous lupus erythematosus (VCLE). This paper reports the immunopathological findings of canine VCLE using samples from 17 affected dogs. Lesional skin sections were stained with monoclonal antibodies specific for CD3 (11 dogs) or a panel of monoclonal antibodies specific for leukocyte antigens (two dogs). Apoptotic cells were detected using the TUNEL method in 12 cases. Direct (14 dogs) and indirect immunofluorescence tests (five dogs) were also performed. Circulating antibodies to extractable nuclear antigens (ENA) were surveyed in 11 dogs by immunoblotting and ELISA. The predominant cells at the dermal-epidermal interface were identified as CD3(+) T lymphocytes expressing CD4 or CD8 and CD1(+) dendritic antigen presenting cells. In 7/12 dogs (58%), apoptosis of basal keratinocyte nuclei was present. Up-regulation of MHCII and ICAM-1 was observed on basal keratinocytes from the two dogs examined. Direct immunofluorescence revealed deposition of immunoglobulins bound to the cytoplasm of keratinocytes (6/14 dogs; 43%), to the dermal-epidermal junction (7/14 dogs; 50%), or to superficial dermal venules (13/14 dogs; 93%). Circulating IgG auto-antibodies targeting one or more ENA were detected in nine (82%) and eight (73%) of 11 dogs by immunoblotting and ELISA, respectively. These auto-antibodies recognized Ro/SSA and/or La/SSB in four (36%) and six (55%) of 11 dogs respectively by these two methods. Altogether, results of these studies provide evidence supporting the hypothesis that canine VCLE is an immunological homologue of subacute cutaneous lupus erythematosus in humans.

Photosensitivity in patients with lupus erythematosus: a clinical and photobiological study of 100 patients using a prolonged phototest protocol

BACKGROUND

There is a clear relationship between ultraviolet (UV) radiation (UVR) and the clinical manifestations of patients with lupus erythematosus (LE). Cutaneous lesions are induced or exacerbated by exposure to UVR. Of patients with LE, 24-83% are reported to be photosensitive to UVR. LE tumidus appears to be the most photosensitive subtype of LE, followed by subacute cutaneous LE (SCLE). In general, the history of patients with LE correlates poorly with the presence or absence of photosensitivity, due to a delayed time interval between UV exposure and exacerbation of skin lesions. Phototesting using artificial UVR and visible light is a reliable way of diagnosing photosensitivity.

OBJECTIVES

To investigate the photoreactivity of patients with various subtypes of LE using an individualized phototest protocol. The results of phototests were correlated with the history of photosensitivity, the subtype of LE, the presence of autoantibodies and the use of anti-inflammatory medication by these patients.

METHODS

Phototesting with UVA, UVB and visible light was performed in 100 patients with LE. The diagnosis of LE was established both on clinical examination and skin histology. Serological studies were also performed in all patients. The phototests were performed on large skin areas of the forearm or trunk; the first dose was twice the minimal erythema dose and the dosage was increased according to the individual reactions of the patients at the test sites. Follow-up of skin reactions at the test sites was performed for up to 2 months. Histological examination of the photoprovoked skin lesions was carried out in 57 patients.

RESULTS

Of the 100 patients included (81 women and 19 men; mean age 41 years, range 17-79), 46 had chronic discoid LE, 30 SCLE and 24 systemic LE. An abnormal reaction to UVR and visible light was found in 93% of our patients with LE. No clinical or histological evidence at the phototest sites of polymorphic light eruption was found. There was no correlation between photosensitivity and LE subtype, presence of autoantibodies or medical history. Concomitant use of anti-inflammatory medication seemed to exert only minimal influence on the results of phototesting.

CONCLUSIONS

When using an extended phototesting protocol, almost all patients with LE in this study showed clinical and histological evidence of aberrant photosensitivity. Therefore, patients with LE should receive thorough advice and instruction on photoprotective measures, regardless of their history, LE subtype or presence of autoantibodies.

Apoptosis in different cutaneous manifestations of lupus erythematosus

BACKGROUND

It has been shown that dysregulation of apoptosis may play an important part in the development of autoimmune diseases such as lupus erythematosus (LE).

OBJECTIVES

The aim of the study was to investigate whether apoptosis may contribute to the pathogenesis of cutaneous changes in LE and whether certain apoptosis-related markers such as Fas antigen, Fas ligand (FasL), Bcl-2 and Bax proteins take part in this process.

METHODS

Cryostat sections of lesional skin from 31 patients with LE-specific skin lesions [discoid (DLE) n = 17, subacute cutaneous (SCLE) n = 10 and acute cutaneous (ACLE) n = 4] and normal skin samples (n = 10) were stained with monoclonal antibodies against Fas antigen, FasL, Bcl-2 and Bax proteins. For the detection of apoptotic nuclei, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling technique (TUNEL) was employed.

RESULTS

The keratinocytes of the epidermis and mononuclear cells of the dermal infiltrate in LE showed a significant increase in Fas antigen expression as compared with normal skin. The anti-Bcl-2 staining intensity within the epidermis was markedly decreased, while the mononuclear infiltrate stained for this protein just like single lymphocytes scattered in normal skin. There was an increase of FasL and/or Bax-positive cells within the dermal infiltrate, but not in the epidermis or in the hair follicles. Accumulation of FasL-bearing cells around hair follicles was a hallmark of DLE. Numerous cells with pyknotic, TUNEL-positive nuclei were demonstrated in the epidermis, in hair follicles and among the cells of the dermal infiltrate. The extent of apoptosis in lesional skin was greater in acute and subacute cutaneous than in discoid forms of LE.

CONCLUSIONS

The exact stimulus triggering apoptosis in cutaneous LE still remains unknown but the present study provides strong evidence that the reduction of Bcl-2 expression in the basal cells is associated with the overexpression of Fas antigen and correlates directly with the extent of apoptosis in the epidermis. Furthermore, the current study indicates that the extent of apoptosis in both the epidermis and dermal infiltrate may correlate with the chronological development of LE skin lesions.

Lymphocytic infiltration of the skin is a photosensitive variant of lupus erythematosus: evidence by phototesting

BACKGROUND

Lymphocytic infiltration of the skin (LIS) is a disorder in which photosensitivity has been suspected but never proven.

OBJECTIVES

To carry out a systematic photobiological investigation in patients with LIS and to compare the photobiological features of LIS with those of other photosensitive disorders.

METHODS

We performed provocative phototesting with ultraviolet (UV) A and UVB in 10 patients with active LIS.

RESULTS

In all patients, UVA and/or UVB elicited abnormal papular phototest reactions resembling lesions of LIS both clinically and histologically. Lesions typically developed 3--6 days (mean +/- SD 100.8 +/- 20.9 h) after the first UV exposure.

CONCLUSIONS

This characteristic latency interval together with certain clinical features, i.e. onset in summer, predilection for the face and persistence of the lesions, indicate that LIS is a photosensitive disorder distinct from polymorphic light eruption but indistinct from lupus erythematosus (LE). Both our photobiological findings and the effective treatment with hydroxychloroquine in half of our patients strengthen the proposal that the two entities LIS and LE tumidus are identical. As diagnosis cannot be made by histological, immunofluorescence or laboratory criteria, provocative phototesting may be a diagnostic aid in this disorder.

Phototesting in Lupus Erythematosus Tumidus—Review of 60 Patients¶

Photosensitivity is an important characteristic feature of several forms of lupus erythematosus (LE), and induction of skin lesions by UV-A and UV-B irradiation has been proved to be an optimal model for evaluating light sensitivity in patients with this disease. Because lupus erythematosus tumidus (LET) has rarely been documented in the literature and is often difficult to differentiate from other photodermatoses such as polymorphous light eruption, we performed photoprovocation tests in 60 patients with LET according to a standardized protocol. Areas of uninvolved skin on the upper back were irradiated with single doses of UV-A (100 J/cm2) and/or UV-B (1.5 minimal erythema dose) daily for three consecutive days. Interestingly, patients with LET are more photosensitive than those with subacute cutaneous lupus erythematosus, and in our study experimental phototesting revealed characteristic skin lesions in 43 patients (72%). Because of the latency period in developing positive phototest reactions, it might be difficult for these patients to link sun exposure with their skin lesions. Furthermore, our data revealed a positive correlation of antinuclear antibodies and positive provocative phototest reactions in these patients as seen for other forms of LE. In conclusion, the high incidence of positive phototest reactions in correlation with the clinical findings, history of photosensitivity and antinuclear antibodies enable the classification of LET as the most photosensitive type of LE.

IFN-gamma transgenic mice: clues to the pathogenesis of systemic lupus erythematosus?

Transgenic mice overexpressing IFN-gamma in the epidermis develop an inflammatory skin disease resembling cutaneous lupus erythematosus shortly after birth. By 3 months of age, most female transgenics develop a lupus-like syndrome characterised by production of IgG anti-dsDNA, antihistone and antinucleosome autoantibodies. The autoantibodies are nephritogenic, with one-third of females developing a severe immune complex mediated glomerulonephritis. Analysis of these transgenics suggests that pathogenic autoantibodies arise via an antigen-driven T-cell-dependent mechanism with apoptotic keratinocytes acting as a potential source of autoantigen. The mechanism of autoantibody production in IFN-gamma transgenics may be relevant to human lupus and is consistent with a central role for cutaneous T cells in the pathogenesis of systemic lupus erythematosus in man.

Cutaneous lupus erythematosus-treatment with pulsed dye laser

Because of its vascular selectivity, the flashlamp-pumped pulsed dye laser (585 nm) is efficacious in the treatment of vascular lesions and is successfully used for the treatment of port-wine stains and haemangiomas in children. Based on the encouraging results with these cutaneous vascular disorders, the cutaneous lesions of patients with lupus erythematosus (LE) have now also been treated with the pulsed dye laser. Cutaneous lesions in lupus erythematosus are often difficult to treat with readily available local therapeutic methods. We report here on a group of 12 patients whose LE lesions were treated with the pulsed dye laser. In 10 patients, the LE was limited to the skin, while two patients had systemic LE (SLE). Even in the two patients with SLE, a significant improvement of skin lesions was achieved. After a mean number of 51 laser sessions, a median clearance rate of 70% was attained for nine patients. In one case, the laser treatment failed to clear the lesions. Two patients did not show any visible improvement of the lesions, but pain and itching were significantly reduced. There were few side-effects. No prolonged laser-induced scarring occurred and in only two patients was hyperpigmentation seen, which had resolved completely after 4 and 5 months, respectively. During a median follow-up of 7 months (range: 3-32 months), only one patient (after a complete clearance of the skin lesions) had a small relapse. In summary, the pulsed dye laser is an effective therapy for the treatment of superficial skin lesions in LE.

Transcriptional activation of endogenous retroviral sequences in human epidermal keratinocytes by UVB irradiation

Ultraviolet radiation is a pathogenic factor in various diseases, e. g., autoimmune disorders such as lupus erythematosus. On the other hand, endogenous retroviruses are discussed as etiologic agents in lupus erythematosus. Therefore, we investigated the influence of ultraviolet irradiation on expression of human endogenous retroviral sequences and human endogenous retroviral sequence promoter-driven transcription of cellular genes using human epidermal keratinocytes as a model system. First, conserved sequences of endogenous retroviral pol genes were amplified from cellular mRNA by reverse transcriptase polymerase chain reaction with degenerate oligonucleotide primers. Polymerase chain reaction products were hybridized in a reverse dot blot hybridization assay to a representative number of distinct cloned human endogenous retroviral pol fragments. Using this method, we could show that irradiation with 30 mJ per cm2 ultraviolet B activates transcription of various endogenous retroviral pol sequences in primary epidermal keratinocytes as well as in a spontaneously immortalized keratinocyte cell line (HaCaT). Interestingly, some of these sequences were found to be closely related to pol sequences of human endogenous retroviral sequences which have been shown to be expressed in autoimmune patients. Analysis of human endogenous retroviral pol expression in vivo using skin biopsies of lupus erythematosus patients revealed similar activation patterns. In a second approach, ultraviolet B- induced chimeric transcripts were isolated which are initiated by human endogenous retroviral promoters and proceed into cellular sequences using a newly established modified differential display polymerase chain reaction technique. The activation of human endogenous retroviral sequence transcription by ultraviolet B may contribute to the pathogenesis of lupus erythematosus, where inappropriate antigenic presentation of ultraviolet B-induced viral and cellular proteins could stimulate autoantibody production.

Clinical and immunological manifestations in 134 Puerto Rican patients with systemic lupus erythematosus

To gain a better understanding of systemic lupus erythematosus (SLE) in Puerto Ricans we studied the clinical and serologic manifestations in a cohort of 134 patients. The female to male ratio was 18:1. Mean age at diagnosis was 32 +/- 12 y. The mean duration of disease and follow-up were 7.4 +/- 6.0 and 5.8 +/- 6.0 years respectively. Mortality was 3%. Photosensitivity (76.9%) and malar rash (71.9%) were the most common clinical manifestations. Arthritis was observed in 67.5% of patients. Anemia was seen in 67.2% of patients, but only 12.7% had autoimmune hemolytic anemia. Leukopenia (41.8%) and lymphopenia (64.9%) were also common. Serositis was observed in only 28%. Severe kidney damage such as nephrotic syndrome (14.2%) or renal failure (4%) was infrequent. Cardiovascular (12.7%) and neurologic (9.0%) manifestations were also uncommon. Antinuclear antibodies (ANA) were detected in 93.3%, anti-dsDNA antibodies in 54.5%, anti-Ro antibodies in 30.1% and anti-La antibodies in 14.2%. Low C3 and low C4 were observed in 38.3% and 35.7% respectively. This study suggests that Puerto Ricans with SLE present a mild form of disease predominantly manifested by cutaneous, musculoskeletal and hematologic involvement, but low prevalence of major organ damage and low mortality.

Phototesting in oriental patients with lupus erythematosus

Light sensitivity is an important clinical characteristic of several forms of lupus erythematosus (LE). Recently, investigations have been able to induce LE-like lesions in LE patients with UVA as well as UVB, although most of these studies were conducted in Caucasians. Thus, there is insufficient data on phototesting in Oriental patients with LE. The aim of this study was to evaluate light sensitivity in Oriental patients with LE. Fifteen patients with various forms of LE were tested. Patients were evaluated by provocative phototesting, and threshold doses of UVA and UVB radiation that produced erythema and pigmentation were determined. The minimal erythema doses (MED) of UVB, immediate pigment darkening (IPD), and minimal tanning doses (MTD) were within the normal range in LE patients compared to a control group. Skin lesions clinically and histologically compatible with LE were induced in two of six patients with SLE, and four of nine patients with DLE. These lesions developed in about 2 weeks (range 5 to 23 days) after irradiation and lasted approximately 1 to 3 months (47 +/- 24 days). The action spectrum of the induced lesions was within the UVB range in four patients, in the UVA range in one patient, and in the UVB and UVA ranges in one patient. We found no correlation between a positive history for UV sensitivity and phototest reactions. In conclusion, the incidence of positive phototest reactions in Oriental patients with LE seems to be similar to or a little lower than in Caucasians. There was no correlation between a positive history for UV sensitivity and phototest reactions.

Phototesting and photoprotection in LE

Photosensitivity and induction of skin lesions following UV radiation is a common problem of patients with cutaneous and systemic forms of lupus erythematosus. The detrimental effect of UV radiation to patients with lupus erythematosus was already recognized in the last century. Skin lesions can now be provoked under standardized conditions allowing the diagnosis and classification of patients with photosensitive disorders. The aim of this review is to give an overview on the history, test procedure and test results in patients with lupus erythematosus.

Photosensitivity in systemic lupus erythematosus: laboratory testing of ARA/ACR definition

OBJECTIVE

The aim of our study was to evaluate the prevalence of photosensitivity in SLE as defined by either clinical or laboratory assessment, the concordance of findings obtained by two methods, and the relationship between photosensitivity and clinical and immunological parameters.

METHODS

Forty-four SLE patients and 31 healthy subjects were included. Patients and controls underwent a standard questionnaire testing and the minimal erythemal dose (MED) measurement performed by Dermalight-Blue Point. The standard questionnaire was designed in order to meet, as near as possible, the definition of photosensitivity included in the ARA/ACR criteria for classification of SLE.

RESULTS

The prevalence of photosensitivity was (patients vs controls): 57% vs 45% according to questionnaire; 79.5% vs 51.6% (P = 0.02) according to MED. The agreement between questionnaire and phototest was absent in SLE (kappa 0.01) and poor in controls (kappa 0.36). Discoid rash was significantly associated with questionnaire positive (P = 0.01) and renal involvement with questionnaire negative results (P = 0.02), serositis with MED abnormality (P = 0.03), malar rash and anti-Sm antibody with MED normal values (P = 0.03 and P = 0.01), respectively). Moreover, by multivariate analysis, malar rash and anti-Sm antibody significantly predicted MED-defined photosensitivity, with probability ranging from 42% (presence of both) to 92% (lack of both).

CONCLUSIONS

Photosensitivity is frequently observed in SLE patients as well as in healthy subjects. Its prevalence is significantly higher in SLE than in controls only when it is detected using the laboratory method. However, due to the difficulty in objectively defining such manifestation, the disagreement between questionnaire and MED results was high and its clinical meaning appears ambiguous. Thus, the use of photosensitivity as a classification criterion for SLE remains questionable, at least when it is assessed according to the ARA/ACR definition.

Significance of the anti-Ro (SS-A) antibody in evaluation of patients with cutaneous manifestations of a connective tissue disease

The anti-Ro(SS-A) antibody is arguably the most important antibody determination except for antinuclear antibodies in evaluation of patients suspected of having lupus erythematosus. During the past 25 years, studies have established the importance of this antibody in the evaluation of patients with atypical lupus erythematosus, who have a photosensitive dermatitis as the presenting sign. The purpose of this review is to demonstrate the utility and the necessity of this antibody determination in the evaluation of all patients with cutaneous manifestations who are suspected of having a connective tissue disease.

Photoimmunology of lupus erythematosus and dermatomyositis: a speculative review

David Norris has proposed a four step model for the pathogenesis of LESSD (1): (1) exposure to UV light induces the release of proinflammaotry epidermal and dermal mediators such as IL-1 and TNF-alpha; (2) these mediators induce changes in epidermal and dermal cells including the induction of adhesion molecules and promotion of the translocation of normally intracellular autoantigen such as Ro/SS-A to the surface of epidermal cells; (3) autoantibody from the circulation binds to autoantigens such as Ro/SS-A that have been translocated to the surface of epidermal keratinocytes and (4) keratinocyte cytotoxicity ensues as the results of lymphoid cells that have been recruited from the circulation recognizing and responding to the Fc domains of autoantibody molecules bound to autoantigen expressed on the surface of keratinocytes (i.e. antibody-dependent cell-mediated cytotoxicity). Although this remains among the most attractive of hypotheses for the explanation of Ro/SS-A antibody-associated forms of LESSD such as SCLE and neonatal LE, it does not address the pathogenesis of other forms of LESSD such as DLE, which are not associated with high-level Ro/SS-A antibody production or other known autoantibody specificities (low-level Ro/SS-A autoantibody production has been noted recently in DLE patients (155)). In addition, this hypothesis implies that the fundamental abnormality in SCLE and neonatal LE is the production of high levels of Ro/SS-A autoantibody; however, equally high levels of Ro/SS-A antibodies having similar molecular specificities are frequently encountered in other conditions such as Sjögren's syndrome in which LESSD is seen only infrequently. Also, a nude mouse model of anti-Ro/SS-A autoantibody in deposition grafted human skin has been developed; however, no inflammation or epidermal injury occurs in these animals (83). Most work has indicated that the action spectrum for Ro/SS-A autoantigen modulation in human epidermal keratinocytes is limited to the UVB spectrum; however, recent studies have suggested that UVA is involved in the elicitation of certain forms of photosensitive cutaneous LE such as SCLE. The hypothesis that CD4+ T cells that are specific for autoantigens in the skin whose expression is altered by UVR exposure might play a role in the expression of LESSD needs to be explored further. Because LE is thought to be a polygenic autoimmune disease, it is possible that polymorphism of genes that govern the skin's response to UVR might be involved in the pathogenesis of photosensitive LESSD. Candidate genes would include: The Ro/SS-A autoantigenic polypeptides and h-YRNA; cytokines, cytokine receptors and adhesion molecules induced on epidermal keratinocytes and dermal endothelial cells by UVR; molecules involved in DNA repair; components of pathways leading to the generation and quenching of oxygen free radicals and components of the UVR-induced apoptosis cascade. Unfortunately, so little is known about DM photosensitivity that it is difficult to even speculate about pathogenetic mechanisms that might be involved other than to extrapolate from the observations and currents of thought relating to photosensitive cutaneous LE. A truly limiting aspect of our understanding in this area has been the absence of working models of the patterns of inflammation seen in LESSD and cutaneous DM. Until such models become available, considering the limitations of human studies, alone it is highly likely that reviews of this subject will continue to be based on much in speculation as observation.

Discoid lupus erythematosus

Discoid lupus erythematosus is a manifestation of chronic cutaneous lupus erythematosus with a small risk of systemic involvement. In this review article, the role of predisposing factors such as haplotype, hormones, antibodies and sunlight are discussed. The clinical features, including variants and associations, and management options are presented.

Standardized ultraviolet-A exposure provokes skin reaction in systemic lupus erythematosus

The immediate, 1 day and 14 days skin reaction was determined in 23 female SLE patients and 23 age-matched controls after standardized exposure to ultraviolet light of the UV-A wavelengths (320-440 nm). Eighteen of the patients and 12 of the controls were photosensitive by history. Eight separate sites on the buttocks were exposed to UV-A light, four sites at doses between 42 and 252 kJ/m2 and four sites with longpass filters (320, 345, 360 and 375 nm). The reactions on test sites were graded by two independent observers unaware of given doses of filter location. All patients and controls reacted with immediate erythema irrespectively of the presence or absence of photosensitivity. After 1 day, 39% of controls and 78% of patients had erythema and the reactions were more pronounced to longwave UV-A light (> 320 nm) in the patients (P < 0.001). After 14 days, six patients, but no control, had persistent erythema (P = 0.04). Interestingly, three of the four patients without anamnestic photosensitivity did not react on days 1 or 14, while the pattern seen in the controls on day 1 was totally unpredictable with regard to reported photosensitivity. These findings strongly suggest that a considerable proportion of SLE patients show pathological skin reactions to physiological doses of longwave UV-A and not only the far more studied shortwave UV-B (290-320 nm). The responsible chromatophore for the UV-A reaction is not known.