Dermatitis Herpetiformis: A Review of Direct Immunofluorescence Findings.

Direct immunofluorescence (DIF) findings in dermatitis herpetiformis (DH) are incompletely defined. The presence and localization of immune reactants in this disorder are reviewed. A retrospective study on 72 biopsies from 71 patients with DH was performed. Deposits of IgG, IgA, IgM, C'3, C1q, and fibrinogen in skin using a DIF test were analyzed. Granular IgA was observed at the dermal-epidermal junction in 65 biopsies and in the fibers of the papillary dermis in 72 samples. IgG, IgM, C'3, C1q, and fibrinogen were detected in the same locations in lower percentages. IgA was present in the vessels of the papillary dermis in 33 biopsies and in the reticular dermis in 10, followed by fibrinogen, C'3, IgM, and IgG. IgA and IgM were detected in the elastic fibers in 17 and 5 samples, respectively. IgA was observed in 19 cases in the arrector pili muscles, and in a few cases, C'3, IgM, and IgG. IgA and other immune reagents were present in the fibers around hair follicles and in the basement membrane of sweat glands and ducts. Immunofluorescence findings in routine DIF studies from skin biopsies of patients with DH cover a much wider spectrum than previously known.

Acquired bullous dermatosis associated with IgA multiple myeloma: a case report.

We present the case of a patient with IgA paraprotein who developed hemorrhagic subepidermal vesicles and bullae with numerous neutrophils. Direct immunofluorescence test (DIF) showed weak deposits of IgA lambda paraprotein at the dermal-epidermal junction and at the intercellular level in the basal layer of the epidermis, and stronger deposits in a perivascular and diffuse pattern in the dermis. Indirect immunofluorescence (IIF) test revealed the presence of circulating IgA lambda antibodies reacting with the intercellular space of monkey and guinea pig esophagus and human skin. A blood test revealed an IgA lambda paraprotein and multiple myeloma stage I(0) was diagnosed in a later hematological study. Dapsone was prescribed and cutaneous lesions improved. This is the second report of subepidermal vesicles and bullae with dermal deposits of IgA paraprotein appearing prior to diagnosis of an IgA multiple myeloma, and it is a unique case with circulating IgA lambda antibodies reacting with the intercellular space of epithelia.

Paraneoplastic pemphigus with negative direct immunofluorescence in epidermis or mucosa but positive findings in adnexal structures.

INTRODUCTION: Paraneoplastic pemphigus (PNP) is considered an autoimmune, multiorgan disease caused by antiplakin antibodies. We present three PNP patients who had negative epithelial direct immunofluorescence (DIF) findings in one or more biopsies. PATIENTS: An early lip biopsy of uninvolved oral epithelia in patient 1 was negative. A later biopsy from foreskin showed intense intercellular immunoglobulin G (IgG) deposits in the epithelia. In the early phase of the disease in patient 2, the intercellular fluorescence was negative in the epidermis, while intercellular IgG and C3 were observed in the sweat ducts. A later biopsy showed weak intercellular epidermal IgG and C3 fluorescence. Patient 3 showed intercellular IgG and/or C3 in follicular, sebaceous and sweat duct structures in several biopsies. No intercellular IgG or C3 was observed in the epithelia. DISCUSSION: The presence of immunoreactants in adnexal structures suggests that desmoplakins can be more strongly expressed in adnexa than in the epidermis, facilitating visualization of antibody deposits. CONCLUSIONS: Negative DIF findings in epithelia do not rule out the diagnosis of PNP, and the presence of IgG and/or C3 at the intercellular level of adnexal structures can help establish this diagnosis.

Consensus statement on definitions of disease, end points, and therapeutic response for pemphigus.

Our scientific knowledge of pemphigus has dramatically progressed in recent years. However, despite the availability of various therapeutic options for the treatment of inflammatory diseases, only a few multicenter controlled trials have helped to define effective therapies in pemphigus. A major obstacle in comparing therapeutic outcomes between centers is the lack of generally accepted definitions and measurements for the clinical evaluation of patients with pemphigus. Common terms and end points of pemphigus are needed so that experts in the field can accurately measure and assess disease extent, activity, severity, and therapeutic response, and thus facilitate and advance clinical trials. This consensus statement from the International Pemphigus Committee represents 2 years of collaborative efforts to attain mutually acceptable common definitions for pemphigus. These should assist in development of consistent reporting of outcomes in future studies.

Usefulness of specific anti-desmoglein 1 and 3 enzyme-linked immunoassay and indirect immunofluorescence in the evaluation of pemphigus activity.

OBJECTIVE: The objective was to assess the relationship between enzyme-linked immunoassay (ELISA) values of desmoglein (Dsg) 1 and Dsg3 antibodies and indirect immunofluorescence (IIF) values of anti-epithelial antibodies with disease activity in patients with pemphigus. PATIENTS AND METHODS: In a retrospective study, we analyzed 353 serum samples taken from 35 patients with pemphigus vulgaris (PV) and nine with pemphigus foliaceus (PF) during the course of the disease. In each sample, we measured anti-Dsg1 and anti-Dsg3 antibodies by ELISA. A receiver operating characteristics (ROC) curve was calculated to determine a cutoff value for anti-Dsg1 and anti-Dsg3 antibodies with optimal sensitivity and specificity. In 263 samples, we compared the ROC curves of anti-Dsg1 and anti-Dsg3 antibodies with the ROC curves of the IIF results. RESULTS: Activity of pemphigus was associated with a wide range of anti-Dsg1 and anti-Dsg3 antibody values. Levels of anti-Dsg1 antibodies showed a better relationship with cutaneous activity of pemphigus than levels of IIF anti-epithelial antibodies. The levels of IIF anti-epithelial antibodies showed a relationship with activity of mucosas similar to the levels of anti-Dsg3 antibodies. DISCUSSION: Abnormal values of anti-Dsg antibodies are not always associated with disease activity. ELISA detects both pathogenic and nonpathogenic anti-Dsg antibodies. CONCLUSIONS: Therapeutic strategies should not be based exclusively on anti-Dsg antibody values. Anti-Dsg1 antibodies showed a closer relationship with skin activity than IIF, while anti-Dsg3 antibodies showed a relationship with mucosal activity similar to the IIF test.

Neutrophilic dermatoses in a patient with collagenous colitis.

We report the case of a 75-year old woman with collagenous colitis who presented with erythematous and edematous plaques on the periorbital and eyelid regions, accompanied by oral ulcers. Histopathology showed a dermal neutrophilic infiltrate plus mild septal and lobular panniculitis with lymphocytes, neutrophils and eosinophils. Five years earlier she had presented a flare of papules and vesicles on the trunk, together with oral ulcers; a skin biopsy revealed a neutrophilic dermal infiltrate and Sweet's syndrome was diagnosed. Both the neutrophilic panniculitis and the Sweet's syndrome were accompanied by fever, malaise and diarrhea. Cutaneous and intestinal symptoms disappeared with corticoid therapy. The two types of neutrophilic dermatoses that appeared in periods of colitis activity suggest that intestinal and cutaneous manifestations may be related.

Enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence testing in a bullous pemphigoid and pemphigoid gestationis.

Enzyme-linked immunosorbent assay (ELISA) is an excellent tool for detection of circulating antibodies against the NC16A portion of BP180 antigen. We compared the sensitivity and specificity of a commercially available BP180-NC16a domain ELISA with that of an indirect immunofluorescence (IIF) testing in the evaluation of bullous pemphigoid (BP) and pemphigoid gestationis (PG), and analyzed the relationship between ELISA results and the presence of IgG deposition, in an epidermal or combined pattern, on direct immunofluorescence (DIF) testing of salt-split skin. ELISA was performed on serum from 28 patients (24 BP, 4 PG) and 50 controls. IIF testing was performed on serum from 27 patients and 98 controls. For the group of 28 patients with BP or PG, ELISA had a sensitivity of 93% and specificity of 96% (P < 0.001), while sensitivity was 74% and specificity 96% (P < 0.001) for IIF testing. In these patients, ELISA has a higher sensitivity than IIF testing, but similar specificity. Evaluation of controls who had IgG deposition on the dermal side of salt-split skin on DIF testing showed specificity for the ELISA of 100% (all four cases negative) and 80% for IIF testing (one of five positive). Positive ELISA correlated with a diagnosis of BP or PG only in patients who had IgG at the basement membrane zone (BMZ) by DIF testing. Overall, ELISA appears to have greater sensitivity and specificity for BP or PG than does IIF testing.

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).

Diagnostic, prognostic and pathogenic value of the direct immunofluorescence test in cutaneous leukocytoclastic vasculitis.

BACKGROUND: No precise studies have been performed on cutaneous leukocytoclastic vasculitis (LV) to establish whether it is better to obtain a skin biopsy from lesional or from perilesional skin for direct immunofluorescence (DIF). There is no agreement on the immunoglobulins most frequently detected and the value of DIF for the classification of cutaneous vasculitis. METHODS: A prospective study of DIF in lesional and perilesional skin was performed in 50 leukocytoclastic vasculitis patients and 15 nonvasculitis patients. RESULTS: We detected a higher level of positivity in involved skin than in uninvolved skin for IgG, IgA, IgM, C3 and fibrinogen but not for C1q. In vasculitic patients, IgA was the immunoglobulin most frequently detected in lesional (82%) and perilesional skin (68%), followed by IgM (56 and 34%, respectively) and IgG (20 and 8%, respectively). Only IgA deposits were associated with the diagnosis of vasculitis, with a sensitivity of 82% in lesional and 68% in perilesional skin, and with a specificity of 73 and 66.7%, respectively. The presence of IgA in lesional skin was associated with renal involvement but there was no association with severity. The presence of IgG or IgM, or the absence of IgA in perilesional skin was related to the presence of cryoglobulins. The absence of IgA in lesional and perilesional skin was also related to hepatitis C virus infection. CONCLUSIONS: DIF findings in involved skin are more closely related to the diagnosis of vasculitis and can give more information about overall renal involvement than findings in uninvolved skin. However, findings in uninvolved skin are more closely related to the pathogenic factors that trigger the development of vasculitis.