A case of anti-laminin γ1 (p200) pemphigoid developed after dipeptidyl peptidase-4 inhibitor administration.

A 73-year-old man with diabetes mellitus was referred to our department for ultraviolet treatment for erythematous skin lesions with itching. On dipeptidyl peptidase-4 inhibitor (DPP-4i) sitagliptin (Januvia®) for diabetes mellitus, the erythematous skin lesions appeared and spread to the whole body. At the initial visit, erythema multiforme-like skin lesions with crusts were observed on the trunk and extremities, and the patient was suspected to have drug eruption. Histopathology demonstrated eosinophilic infiltration in the superficial dermis and inflammatory cell infiltration in the epidermis. Sitagliptin was discontinued, and erythematous lesions improved with oral prednisolone. Thereafter the patient was treated with phototherapy and  betamethasone sodium phosphate infusion for residual prurigo. However, blistering skin lesions appeared 5 months later. Histopathological findings were subepidermal blisters with eosinophilic abscess, and bullous pemphigoid was suspected. CLEIAs for autoantibodies to desmoglein 1 (Dsg1), Dsg3 and BP180 were negative. Direct immunofluorescence showed linear depositions of immunoglobulin G (IgG) and C3 at the epidermal basement membrane zone, and indirect immunofluorescence detected IgG anti-epidermal basement membrane zone antibodies, reacting with the dermal side of 1M NaCl-split normal human skin. IgG antibodies reacted with 200 kDa laminin γ1 (p200) by immunoblotting using dermal extracts. These results indicated that this patient was diagnosed with anti-laminin γ1 (p200) pemphigoid developed after DPP-4i administration. Although reports of DPP-4i-related bullous pemphigoid have accumulated, cases of anti-laminin γ1 (p200) pemphigoid developed after DPP-4i administration are rarely reported.

Omalizumab as an alternative therapeutic tool in the treatment of bullous pemphigoid: A case report.

Bullous pemphigoid (BP) is an acquired autoimmune bullous disease characterized by autoantibodies against the hemidesmosomal proteins found in the basal keratinocytes of the basement membrane zone (BMZ): a 180 kDa protein (type XVII collagen) mainly and the 230 kDa antigen. There is such evidence that the antibodies against the BMZ components are not only of IgG type, but also this bullous disease may have IgE antibodies directed to the BMZ that contribute to the pathogenesis of the disorder. IgE is not only thought to contribute to the pathogenesis of BP, it has also been suggested that eosinophils play a role in the development of the first signs associated with BP. A humanized monoclonal antibody directed to IgE, omalizumab, is approved for the treatment of severe asthma and chronic spontaneous urticaria, and it may be useful in the treatment of BP in the first stages of the disease.

Biological therapy of autoimmune blistering diseases.

INTRODUCTION: Autoimmune blistering skin diseases are a group of disorders subdivided according to the location of blister formation: intraepidermal blistering in the pemphigus group and subepidermal in the pemphigoid group. These conditions are clinically heterogeneous and are treated with systemic corticosteroids and/or other forms of immunosuppression on the basis of clinical subtype and disease severity. These approaches may not be effective for the induction and maintenance of clinical response or need to be stopped because of intolerable side effects. AREAS COVERED: Biological therapies can represent a valid alternative strategy in various autoimmune blistering disorders and this review article will address this issue with a special focus on pemphigus vulgaris and bullous pemphigoid. These biological approaches are designed to target B cells, autoantibodies, complement proteins, and several cytokines. EXPERT OPINION: Innovative strategies for the treatment of autoimmune blistering conditions primarily depend on the use of drugs with a high degree of specificity targeting crucial steps in the immunopathology of these disorders. Novel biological agents offer treatment alternatives to patients with autoimmune blistering conditions by targeting B cells, pathogenic autoantibodies, complement and cytokines.

Oral administration of the selective GPR120/FFA4 agonist compound A is not effective in alleviating tissue inflammation in mouse models of prototypical autoimmune diseases.

ω3-polyunsaturated free fatty acids (ω3-PUFAs), particularly docosahexaenoic (DHA) and eicosapentaenoic acid (EPA), are thought to exert health promoting effects in metabolic and in inflammatory diseases. The molecular mechanisms of these beneficial effects are only partially understood. DHA and EPA activate Free Fatty Acid receptor 4 (GPR120/FFA4). Recently, the first orally available, synthetic ligand of FFA4, 3-[2-chloro-5-(trifluoromethoxy)phenyl]-3-azaspiro[5.5]undecane-9-acetic acid ("compound A"; cpd A) has been developed. Cpd A exhibits distinctly higher potency, efficiency, and selectivity at FFA4 than ω3-PUFAs and ameliorates insulin resistance and adipose tissue inflammation in the mouse. With GPR120/FFA4 activation believed to also attenuate tissue inflammation in autoimmune diseases, cpd A may also have a beneficial effect in these diseases. We have therefore addressed the therapeutic potential of cpd A in mouse models of three prototypical autoimmune diseases, specifically psoriasis, rheumatoid arthritis, and bullous pemphigoid. The effect of cpd A on the course of Aldara™-induced psoriasis-like dermatitis, K/BxN serum transfer arthritis, and antibody transfer pemphigoid disease-like dermatitis was scrutinized. Cpd A did not alter the course of Aldara-induced psoriasis-like dermatitis, K/BxN serum transfer arthritis, or antibody transfer pemphigoid disease-like dermatitis. Our results suggest that therapeutic regimens solely relying on FFA4 activation do not bear the potential to treat inflammatory diseases. With cpd A distinctly more potent in activating GPR120/FFA4 than ω3-PUFAs, this also suggests that GPR120/FFA4 activation by ω3-PUFAs does not significantly contribute to the health-promoting effects of ω3-PUFAs in autoimmune diseases.

Intravenous IgG Reduces Pathogenic Autoantibodies, Serum IL-6 Levels, and Disease Severity in Experimental Bullous Pemphigoid Models.

Bullous pemphigoid (BP) is an autoimmune blistering disease characterized by autoantibodies to COL17. Currently, systemic corticosteroids are used as first-line treatments for BP; alternatively, intravenous administration of high-dose IgG (IVIG) has been shown to be effective for patients with steroid-resistant BP in clinical practice. However, the effect of IVIG on BP has not fully been investigated. To examine the effects and mechanisms of action of IVIG against BP, we performed IVIG experiments using two experimental BP mouse models. One is a passive-transfer BP model that reproduces subepidermal separation in neonatal mice by the passive transfer of IgGs against COL17, such as polyclonal or monoclonal mouse IgG or IgG from BP patients. The other is an active BP model that continuously develops a disease phenotype in adult mice. IVIG decreased pathogenic IgG and the disease scores in both models. Injected IVIG distributed throughout the dermis and the intercellular space of the lower epidermis. Notably, IVIG inhibited the increase of IL-6 in both models, possibly by suppressing the production of IL-6 by keratinocytes. These results suggest that the inhibitory effects of IVIG on BP are associated with the reduction of pathogenic IgG and the modulation of cytokine production.

Heat shock protein 90: a pathophysiological factor and novel treatment target in autoimmune bullous skin diseases.

The chaperone heat shock protein 90 (Hsp90), a cell stress-inducible molecule that regulates activity of many client proteins responsible for cellular growth, differentiation and apoptosis, has been proposed as an important therapeutic target in patients with malignancies. More recently, its active participation in (auto)immune processes has been recognized as evidenced by amelioration of inflammatory disease pathways through pharmacological inhibition of Hsp90 in rodent models of autoimmune encephalomyelitis, rheumatoid arthritis and systemic lupus erythematosus. Based on own current research results, this viewpoint essay provides important insights that Hsp90 is also involved as a notable pathophysiological factor in autoimmune blistering dermatoses including epidermolysis bullosa acquisita, bullous pemphigoid and possibly dermatitis herpetiformis. The observed in vitro, ex vivo and in vivo efficacy of anti-Hsp90 treatment in experimental models of autoimmune bullous diseases and its underlying multimodal anti-inflammatory mechanisms of interference with key contributors to autoimmune-mediated blister formation supports the introduction of selective non-toxic Hsp90 inhibitors into the clinical setting for the treatment of patients with these disorders.

Localized bullous pemphigoid induced by photodynamic therapy.

Topical photodynamic therapy (PDT) causes localized phototoxicity and has been shown both in vitro and in humans to have immunomodulatory and immunosuppressive effects. We report a case of localized bullous pemphigoid (BP) developing after PDT. Although BP has been reported to develop following cutaneous insults such as surgery, radiotherapy, psoralen ultraviolet A (PUVA) and ultraviolet B phototherapy, PDT has not previously been reported as a trigger. Possible mechanisms include direct mechanical injury to the basement membrane and subsequent autoantibody formation, an indirect immunomodulatory effect of PDT, or most likely, precipitation of BP in individuals with pre-existing low titres of epidermal autoantibodies (so-called subclinical BP). PDT should be added to the list of possible exogenous triggers for BP and this condition should be considered if blistering develops following PDT.

Bullous pemphigoid in an infant using complementary medicine.

Bullous pemphigoid (BP) is an acquired immunobullous disorder rarely seen in childhood. We report the case of an infant with BP successfully treated with oral corticosteroids. The onset of BP was associated with use of complementary medications and we speculate that these may have been triggering factors.

Bullous pemphigoid in a patient with psoriasis during the course of PUVA therapy: study by ELISA test.

A 65-year-old woman had a history of deep vein thrombosis and depression. Psoriasis was diagnosed in 1986 and various topical and systemic therapies, singly or in combination, were prescribed: tar, topical corticosteroids, cyclosporine, etretinate, and methotrexate. Two courses of oral and one course of bath psoralen plus UVA (PUVA) therapy (cumulative dose, 467 J/cm(2)) and UVB (2.96 J/cm(2)) had been given. In January 1999, she developed a flare of generalized psoriasis. In May 1999, therapy with PUVA (8-methoxypsoralen) plus topical acetonide triamcinolone 0.1% was initiated. At the time, she was taking acenocoumarol, lorazepam, and hydroxyzine chlorhydrate. In August 1999, at session 30, when the dose of UVA was 9 J/cm(2), and the total dose was 205 J/cm(2), a bulla appeared on the dorsum of the toe and was controlled with topical antibiotics. Five further sessions of PUVA were given and a generalized itching bullous eruption appeared all over the body. PUVA was stopped and the patient was hospitalized. On physical examination, extensive psoriatic plaques plus vesicles and bullae on the normal skin and on psoriatic lesions were observed all over the body (Fig. 1). Histopathologic study of a lesion showed a subepidermal vesicle containing fibrin, neutrophils, and a few eosinophils. No sunburn cells were observed (Fig. 2). The direct immunofluorescence (DIF) test of perilesional uninvolved skin revealed immunoglobulin G (IgG) (Fig. 3) and C3 at the dermal-epidermal junction. The DIF study using the patient's skin, previously treated with 1 m NaCl, localized the IgG at both the epidermal and dermal sides of the basement membrane zone (Fig. 4). Bullous pemphigoid (BP) was diagnosed and therapy with prednisone (60 mg/day) was started. The disease was well controlled in 3 weeks. The dose of prednisone was tapered and stopped 20 months later, without any recurrence. Study of the antibodies by the indirect immunofluorescence (IIF) test, using monkey esophagus and guinea pig as substrate, was positive at a titer of 1/160 in September 1999. The titer decreased to 1/10 in January 2000, and was negative in July 2000. An enzyme-linked immunosorbent assay (ELISA) test, performed using the commercial kit MBL, which identifies antibodies directed against epitopes of the extracellular fragment NC16 of antigen 2 of BP, was positive at 15 U/mL (normal value, < 9 U/mL) in September 1999, and negative in July 2000 (Table 1).

Ocular autoimmune pemphigoid and cyclosporin A.

BACKGROUND: Ocular pemphigoid is a chronic autoimmune disease that leads to vision lost. In its etiology participate autoantibodies against the connective tissue of the conjunctiva of different isotypes (IgM, IgG and IgA) as well as the complement system (C3). Lymphocytes of the CD4 + and CD8 + phenotypes and monocytes were detected in the infiltrates of the biopsies of the conjunctiva. MATERIAL AND METHODS: We treated and studied 82 patients who had several topical and systemic treatments during years to alleviate this condition but whose side effects limited their usefulness. We started the administration of cyclosporin-A (Cy-A) 100 mg/day per os and diminishing gradually the intake of steroids. The relief of ocular pain and headache were the first symptoms that changed the patients' quality of life. Ophtalmological controls revealed improvement of the lesions of the conjunctiva and cornea and subsequent biopsies showed a marked decrease in the cellular infiltrates and in antibody deposits. CONCLUSIONS: Thus, Cy-A is an useful treatment for ocular chronic autoimmune pemphigoid and eventually azathioprine (50 mg/day) can cheaply replace it although its well-known toxicity.

[Topical tacrolimus treatment for ocular cicatricial pemphigoid]. / Traitement d'une localisation oculaire de pemphigoïde cicatricielle par tacrolimus topique.

BACKGROUND: Ocular involvement in cicatricial pemphigoid often occurs from the onset. Certain forms are seen only in this condition. OBSERVATION: A 31-year-old woman presented highly inflammatory conjunctivitis for several months associated with bilateral symblepharons and superficial punctuate keratitis around the left eye refractory to treatment. The patient had a history of mouth ulcers and sores on the scalp. Examination showed scalp lesions with crusts. Histological examination of these lesions revealed dermal-epidermal cleavage. Direct immunofluorescence showed sub-membrane deposits. Anti-basal membrane antibodies were positive. Immunotransfer confirmed the presence of circulating antibodies. This condition was controlled following administration of three courses of cyclophosphamide as a bolus. However, the symblepharons persisted in both eyes. Improvement lasted 4 years. The patient again consulted for inflammatory conjunctivitis and superficial punctate keratitis resulting in invalidating loss of visual acuity, associated with hypereosinophilia. Cortisone eye drops alone resulted in no improvement. Treatment was initiated with topical tacrolimus (Protopic) 0.03% comprising once-daily application to the conjunctiva in the evening. This therapy was well tolerated, and 2 daily applications could be given, followed by a dosage of 0.1%. Improvement was rapid and spectacular, with frank amelioration of visual acuity and resolution of the patient's keratitis. Treatment was continued for 4 months and gradually reduced to the 0.03% dosage level, with increasingly wide intervals between applications. There has been no relapse within the 12 months following the end of treatment. DISCUSSION: Standard treatment of pharmacological cicatricial pemphigoid involves systemic immunosuppression since topical anti-inflammatories are ineffective. The mortality associated with this disease is due to iatrogenic complications. Tacrolimus exhibits extremely good penetration of the conjunctiva. Following administration at a concentration of 0.06% 3 times daily in 15 patients with inflammatory disease of the conjunctiva or the cornea, improvement was seen in 10 of these patients at 26 weeks. Tacrolimus appears to act through immunomodulatory and anti-inflammatory mechanisms. It induces local inhibition of T lymphocyte activation and reduces production of pro-inflammatory lymphokines. Oral tacrolimus cannot be used to control cicatricial pemphigoid refractory to standard immunomodulators. However, 3 three other cases involving topical treatment of cicatricial pemphigoid showed marked efficacy of treatment given for 2 to 6 months, with complete tolerability. Thus, topical tacrolimus appears to constitute an interesting alternative treatment in cicatricial pemphigoid.

Bullous pemphigoid in a patient treated with UVA-1 phototherapy for disseminated morphea.

Bullous pemphigoid is an autoimmune disease of the skin characterized by the production of antibodies directed at structures of the basement membrane zone (BMZ) leading to subepidermal blisters. Several causative triggers have been described in the literature, among them UV light. Here, we report on a 73-year-old Caucasian female with disseminated morphea who developed blisters on her extremities after receiving whole-body UVA-1 phototherapy. The initial differential diagnosis of a phototoxic versus photoallergic reaction was ruled out as the lesions continued to spread after discontinuation of phototherapy. Histological and direct immunofluorescence examination showing a subepidermal blister and linear IgG deposits along the BMZ along with detection of circulating anti-BMZ antibodies led to the diagnosis of bullous pemphigoid. Immunosuppressive therapy resulted in regression of all blisters. After ruling out other possible causes, such as neoplasias or drugs, we conclude that UVA-1 has to be regarded as the most likely trigger of the disease.

Intracellular ionic changes induced by bullous pemphigoid IgG subclasses.

To ascertain whether membrane signal transduction is induced by bullous pemphigoid (BP) antibody and whether cell lysis is induced by its complement activation, we assessed the intracellular Ca2+ concentration ([Ca2+]i), intracellular pH, membrane potential and morphology of living cells by following the time course of fluorescence intensity of Fluo-3/AM, Snaff-1/AM, Dioc-5 and Luciffer yellow, respectively. A transient increase of Fluo-3 fluorescence intensity in DJM-1 cells (a squamous cell carcinoma line) was revealed when the cells were incubated with 2 of five IgG1 BP antibodies. However, no transient increase of Fluo-3 fluorescence intensity was revealed when the cells were incubated with IgG2 and IgG4 BP antibodies. A transient increase of Fluo-3 fluorescence intensity was revealed in DJM-1 cells incubated with 3 of seven IgG1 and 1 of four IgG2 BP antibodies in an EGTA-containing low-Ca2+ medium. On the other hand, the Dioc-5 fluorescence intensity did not change significantly, though the increase of Fluo-3 fluorescence intensity was observed. The increase of Snarf-1 fluorescence intensity was revealed in DJM-1 cells incubated with 2 of five IgG1 BP antibodies, but was not revealed in the cells incubated with IgG2 or IgG4 of BP antibodies. Study of complement activation by BP IgG1 showed a transient increase of Fluo-3 fluorescence intensity of with 3 of five IgG1 BP antibodies when DJM-1 cells were incubated with complement-supplemented normal-Ca2+ medium. At the same time, however, endocytosis and cell lysis were not observed with 2 IgG1 BP antibodies which did induce an increase of Fluo-3 fluorescence intensity when Lucifer-yellow-loaded DJM-1 cells were incubated with complement-supplemented normal-Ca2+ medium. We examined next whether anti-180 kD BP antigen monoclonal antibodies (mAbs R-223 and 233) induce an increase of Fluo-3 fluorescence intensity. MAb R-223 did not induce any increase of Fluo-3 fluorescence intensity in DJM-1 cells, when incubated with normal- and low-Ca2+ media However, mAb R-223 induced a transient increase of Fluo-3 fluorescence intensity in DJM-1 cells when incubated with complement-supplemented normal-Ca2+ medium. MAb 233 did not induced an increase of Fluo-3 fluorescence intensity in DJM-1 cells when incubated with normal- and low-Ca2+ media. These results suggest that the BP IgG1 induces Ca2+ release from intracellular storage sites, however, the complement activated by BP IgG1 does not induce cell lysis. It could not be confirmed that anti-180 kD BP antigen antibody induced Ca2+ release from intracellular storage sites.

[PUVA irradiation decreases the binding of membrane and basement membrane markers to human epidermis in vitro]. / PUVA-Bestrahlung vermindert die Bindung von Membran- und Basalmembran-Markern an humane Epidermis in vitro.

PUVA effects on frozen sections of human epidermis were investigated (20 micrograms 8-methoxypsoralen/ml; UVA wavelength 365 +/- 5 nm; radiation dose between 2 X 10(2) and 2 X 10(2) J/m2). The quality of the glycocalyx was characterized by lectins labeled with FITC (HPA, PHA, LCA, PNA, SBA, RCA, GCA I, UEA I). Serum antibodies of bullous pemphigoid (BP) served as membrane markers for the basement membrane. Fixed BP antibodies were detected by FITC-antihuman IgG. The fluorescence intensity was markedly decreased at a dose of 2 X 10(5) J/m2; 2 X 10(4) J/m2 were less effective. At 2 X 10(3) J/m2, there was nearly no alteration of the fluorescence intensity observed. Changes were seen in the case of BP antibodies and lectins, except UEA I. The relatively high intensity (radiation dose) and the effects immediately observable suggest direct membrane alterations by PUVA in vitro.

The effect of retinoic acid on the expression of pemphigus and pemphigoid antigens in cultured human keratinocytes.

Vitamin A and its derivatives (retinoids) have both profound effects on epidermal differentiation and beneficial therapeutic effects in various dermatologic diseases. In order to understand these effects, much work has been done with cultured keratinocytes, which show specific morphologic, cellular, and biochemical changes modulated by retinoids. In an attempt to further define specific molecular effects of retinoids in cultured human keratinocytes, we studied the expression of pemphigus (P) and pemphigoid (BP) antigens by human keratinocytes cultured with retinoic acid (RA) in concentrations which modulated differentiation. Cultures of human keratinocytes in medium with 10% delipidized fetal bovine serum (vitamin A-depleted medium) demonstrated areas of extensive differentiation with flattened stratifying cells, keratohyaline granules, and an anucleate stratum corneum-like superficial layer. These cells also synthesized a 67 kd keratin, characteristic of well-differentiated epidermis. In contrast, cultures of human keratinocytes in the same medium supplemented with (10(-7) M, 3 X 10(-7) M, or 10(-6) M) RA demonstrated less differentiated small cuboidal cells that were stratified but did not form an anucleate layer or keratohyaline granules, and did not synthesize the 67 kd keratin. In order to detect P and BP antigens in these cultures, we used indirect immunofluorescence. In vitamin A-depleted cultures, P antigen either was not detected or was seen focally on the cell surface of basal cells. BP antigen was seen on the basal pole of the basal cells, approximating its in vivo location. In RA-treated cells, P antigen was seen on the cell surface of most of the cells, and BP antigen was seen throughout the cytoplasm of the basal cells. In order to study the expression of newly synthesized antigens, we radiolabeled cultures with 14C-amino acids and quantitatively immunoprecipitated the antigens, which were then identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis. We detected a major decrease in newly synthesized P antigen precipitated from extracts of vitamin A-depleted cells compared to RA-supplemented cells, whereas amounts of newly synthesized BP antigen were about the same. Taken together these data demonstrate that RA, at concentrations that decrease differentiation of cultured human keratinocytes, increases the expression of P antigen and changes the subcellular location of BP antigen.

The alterations of keratinocyte surface and basement membrane markers by treatment with 8-methoxypsoralen plus long-wave ultraviolet light.

The alterations of keratinocyte surface and basement membrane markers by treatment with 8-methoxypsoralen (8-MOP) plus long-wave ultraviolet (UVA) light (PUVA) were examined in guinea pig skin using immunofluorescence (IF) microscopy. Following a single PUVA treatment (UVA doses: 1.8 - 7.2 J/cm2), reactivity with pemphigus and pemphigoid sera, rabbit anti-guinea pig epidermal cell serum, and fluorescein-conjugated concanavalin A was decreased in intensity in a dose-dependent fashion. Fluorescence became distinctly less pronounced by day 2 postirradiation and recovered between days 6-10. IF with rabbit antiglomerular basement membrane antibodies, which cross-reacted with the basement membrane of the skin, apparently was unaltered within this energy dose range. 8-MOP or UVA alone did not change the reactivity with any reagent. These results suggest that PUVA treatment affects keratinocyte membrane markers and pemphigoid antigens but not some of the basement membrane antigens.