Immunofluorescence microscopy of healthy skin from patients with systemic lupus erythematosus: more than just the lupus band

Lupus band test can be used in combination with anti-chromatin antibodies and complement analysis to predict transition from cutaneous to systemic lupus

The lupus band test (LBT) is frequently performed for patients with lupus erythematosus (LE) but its capacity to discriminate cutaneous (C)LE from systemic (S)LE is debated, as well as its association with serum antinuclear antibodies (ANA) and complement reduction. Among 158 patients, 56 received retrospectively a diagnosis of CLE, 37 have SLE and 65 other skin disorders. Considering 29 clinical, histopathologic, LBT, and serological parameters: 5 parameters were effective in distinguishing LE from other skin disorders (e.g. skin photosensitivity, LBT positivity, basal vacuolar changes, thickening of the basement membrane, and anti-SSA-60 kDa); and 8 parameters were able to separate SLE from CLE (e.g. arthritis, lupus nephritis, hematological manifestations, Raynaud/sicca manifestations, anti-chromatin, anti-dsDNA, and low levels of C3/4). A positive LBT was further determined to be associated with systemic manifestations when associated with anti-chromatin response and complement reduction in the profile of patients evolving to a systemic form of lupus.

Proteome study of cutaneous lupus erythematosus (CLE) and dermatomyositis skin lesions reveals IL-16 is differentially upregulated in CLE

Background

The objective of the study was to explore the disease pathways activated in the inflammatory foci of skin lesions in cutaneous lupus erythematosus (CLE) and dermatomyositis (DM).

Methods

Skin biopsies acquired from active CLE and DM lesions, patient (PC), and also healthy controls (HC) were investigated. Biopsy sections were examined by a pathologist, inflammatory foci were laser micro-dissected and captured, and proteins within captured tissue were detected in an unbiased manner by mass spectrometry. Protein pathway analysis was performed by the string-db.org platform. Findings of interest were confirmed by immunohistochemistry (IHC).

Results

Proteome investigation identified abundant expression of interferon-regulated proteins (IRP) as a common feature of CLE and DM. Interleukin (IL)-16 was the only abundant cytokine differentially expressed in CLE compared to DM. Caspase-3, an enzyme that cleaves IL-16 into its active form, was detected in low levels. Significantly higher proportion of IL-16- and caspase-3-positive cells was identified in CLE lesions in comparison with DM, PC, and HC. Proteomic results indicate more abundant complement deposition in CLE skin lesions.

Conclusions

Using unbiased mass spectrometry investigation of CLE and DM inflammatory infiltrates, we confirmed that high IRP expression is a common feature of both CLE and DM, while IL-16 is the only differentially expressed cytokine in CLE. IHC confirmed high expression of IL-16 and caspase-3 in CLE. Our novel molecular findings indicate that IL-16 detection could be useful in differential diagnostics between the two conditions that can display similar histopathological appearance. IL-16 could be of interest as a future therapeutic target for CLE.

Degree of Histologic Inflammation in Lupus Erythematosus and Direct Immunofluorescence Results: Red and Inflamed Lesions Do Not Increase the Chances of Getting a Bright Band

Background:

In the diagnostic work-up of lupus erythematosus (LE), direct immunofluoresence (DIF) examination could be helpful. Classically, clinically red lesions are targeted by clinicians in the hope of yielding an informative DIF result. However, the investigative correlation between the degree of inflammation and DIF positivity has never been published in the literature.

Objective:

In this study, we sought to discover if histologically inflamed lesions correlated with DIF positivity results.

Method:

We studied 112 lesions histologically consistent with LE and correlated the degree of histologic inflammation on the DIF hematoxylin and eosin-stained biopsy with DIF positivity. The degree and location of the inflammation, as well as the involvement of the dermoepidermal interface, were documented.

Results:

A positive lupus band test was defined as the presence of either (1) granular IgG alone ± other immunoglobulins and/or C3 or (2) granular IgM or Ig A plus other immunoglobulins ± C3. Fifty-four of 112 (48%) cases had positive DIF (DIF+) results, 26 of 112 (23%) had negative DIF (DIF-) results, and 32 of 112 (29%) had nonspecific DIF patterns. Of the DIF+ cases, 41 of 54 (76%) showed some degree of inflammation, whereas 25 of 26 (96%) DIF- cases had inflammation ( p − .60). Most of the biopsies in the study (85%) were inflamed, but the degree and location of the inflammation had no influence on DIF+ results. The intensity of the DIF+ band further failed to show any relationship with the degree of inflammation.

Conclusion:

The level of inflammatory activity in a clinical lesion fails to correlate with DIF positivity. Furthermore, other common histopathologic findings of LE are not predictive of DIF results.

Lupus band test and disease activity in systemic lupus erythematosus: does it still matter?

BACKGROUND

Lupus band test still has no clearly defined position within either diagnostic or disease activity measuring tools for systemic lupus erythematosus (SLE).

OBJECTIVES

We tested the hypothesis that positive LBT correlates with global activity of SLE measured by the SLE Disease Activity Index (SLEDAI) score.

METHODS

In total, 90 SLE patients who underwent biopsy of sunprotected non-lesional (SPNL) skin were studied prospectively. The skin specimen was processed for standard direct immunofluorescence. The patients were classified into groups as negative and positive LBT, and the latter were further subdivided on the basis of the type and morphology of the deposits. Every patient was thoroughly examined and assigned a SLEDAI score. The relationship between LBT findings and SLEDAI score was analysed.

RESULTS

The disease was significantly more active in patients with positive LBT and in those with a higher number of deposited immunoreactants. Almost all patients with renal involvement had a positive LBT.

CONCLUSIONS

LBT on SPNL skin may be a good marker of severe disease at presentation, particularly when three immunoglobulins are found at the dermoepidermal junction.

[Subacute cutaneous systemic lupus erythematosus. Presentation of two clinical cases]

We present two cases of systemic lupus erythematosus (SLE) which began with subacute clinical manifestations. Both cutaneous and systemic lupus are the result of interactions between susceptibility genes and environmental factors such as ultraviolet radiation, giving rise to an anomalous response with hyperreactivity of T and B lymphocytes. Over 50 % of subacute cutaneous lupus cases have or will have SLE, while only 16 to 61 % of SLE cases have acute cutaneous lupus lesions.

When to request immunofluorescence: practical hints

This review highlights important considerations in obtaining good skin biopsy specimens to optimize results of direct immunofluorescence (IF) studies and also summarizes the various patterns of cutaneous IF deposition and their associated diagnoses. IF findings of immunobullous diseases, lupus erythematosus, vasculitis, lichen planus, and erythema multiforme are included. The uses of indirect IF studies are also reviewed including newer modifications that are valuable in helping to diagnose epidermolysis bullosa acquisita and paraneoplastic pemphigus.

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.