Interleukin-2 production in bullous pemphigoid

Clinical and Laboratory Evaluation of Hemocarboadsorption in Autoimmune Bullous Dermatoses

Hemocarboadsorption (HCA) with the following immunosuppressive therapy was used to treat 48 patients with pemphigus vulgaris (PV) and 31 patients with bullous pemphigoid (BP) in the acute phase. The levels of autoantibodies, eicosanoids, endoproteases and their inhibitors as well as interleukin (IL) 1 and IL 2 production and absorption of exogenous IL 2 were examined in the treatment dynamics. The therapeutic effect of HCA was displayed in prompt disease remission in 43 PV and 29 BP patients. Clinical improvement was accompanied by antibody elimination and interleukin cascade reaction normalization. HCA resulted in growth of patients’ serum immunosuppressive activity. It was concluded that HCA has some immunoregulatory effect.

Increased serum levels of interleukin (IL)-5, IL-6 and IL-8 in bullous pemphigoid

Some cytokines have been suggested to take part in the blister formation in bullous pemphigoid (BP). However, the roles of the cytokines are only partly understood. To elucidate the involvement of cytokines in the immunological mechanisms in BP, we investigated the serum levels of interleukin (IL)-2, IL-4, IL-5, IL-6, IL-8, IL-13, soluble IL-2 receptor and soluble CD23 in patients with BP, and the correlation between cytokine levels and other clinical and laboratory data. Serum levels of these cytokines and soluble receptors were determined by enzyme-linked immunosorbent assay in 19 patients with BP and in 16 normal control subjects. Serum levels of IL-5 (P < 0.0001), IL-6 (P < 0.01) and IL-8 (P < 0.05) were significantly higher in BP patients than in the control subjects. Other cytokines and soluble receptor levels were not significantly different. Serum levels of IL-6 (P < 0.05) and IL-8 (P < 0.05) were significantly decreased after treatment when skin lesions disappeared. These results suggest that serum levels of IL-6 and IL-8 could be indicators of disease activity of BP.

Evidence for cell-mediated immune mechanisms in the pathology of pemphigus

Pemphigus is an autoimmune blistering disease in which autoantibodies have clearly been shown to be pathogenic. Because autoantibodies are also found in uninvolved skin, further mechanisms may be important in the development of pemphigus lesions. In addition to granulocytes, mononuclear cells are commonly found in pemphigus lesions. To elucidate the role of mononuclear cells in the pathology of this disease, we determined the levels of soluble interleukin-2 receptor in blister fluid and serum samples from pemphigus patients prior to treatment. The interleukin-2 receptor (IL-2R) is expressed on activated mononuclear cells. Depending on its rate of synthesis, a portion is released from the cell surface in a soluble form (sIL-2R). In blister fluid, sIL-2R levels were 2186 +/- 288 U/ml (+/- SD), which was significantly higher than levels in concurrently obtained serum samples (1299 +/- 165 U/ml; P < 0.001). In suction blisters in volunteers, and in patients with second-degree burns or friction-induced bullae, sIL-2R levels were normal in both blister fluid and serum. In pemphigus patients, sIL-2R serum levels continuously declined during systemic therapy, correlating with disease activity. Immunohistological studies demonstrated a marked increase in IL-2R+ cells in both the epidermis and dermis of lesional skin compared with perilesional skin. In the dermis, CD3+ T cells predominated, whereas monocytes/macrophages were most frequent in the epidermis. In pemphigus vulgaris, monocytes/macrophages were restricted to the basal keratinocytes, whereas in pemphigus foliaceus, they were found throughout the lesional epidermis. Our data indicate that activated mononuclear cells are present in lesional skin of pemphigus patients, and may contribute to the pathology of this disease.

The interleukin-2 receptor in lesions and serum of bullous pemphigoid

The interleukin-2 receptor (IL-2R) is mainly expressed on activated T cells. Depending on its rate of synthesis, a portion is released from the cell surface as soluble IL-2R (sIL-2R). Since the role of mononuclear cells in the pathology of bullous pemphigoid (BP) is not well understood, we determined the sIL-2R in both blister fluid and serum of 15 BP patients with generalized disease before initiating systemic treatment. In addition, we obtained both lesional and perilesional skin biopsies and examined the mononuclear infiltrate with a panel of monoclonal antibodies. In BP blisters, sIL-2R levels were significantly increased (2070 +/- 350 U/ml), (+/- SEM) compared with serum samples taken at the time of blister puncture (1340 +/- 290 U/ml). In six patients with blisters due to second-degree burns or friction and in five suction blister volunteers, sIL-2R levels were normal in both blisters and serum. In BP, elevated serum levels decreased to normal during therapy, correlating with disease activity. The immunohistology showed that 30% of mononuclear cells in the dermal infiltrate of lesional skin expressed the IL-2R, whereas only 15% were positive in perilesional skin. IL-2R-positive cells are the most likely source of the shed receptor in BP blisters. Our results indicate the presence of activated T cells in lesions and peripheral blood of BP and thus underline the importance of cell-mediated immune mechanisms in the pathology of this disease.

Interleukin-2 receptor expression and interleukin-2 production in bullous pemphigoid

Expression of interleukin-2 (IL2) receptors was studied on peripheral blood lymphocytes (PBLs) in 25 patients with bullous pemphigoid. Analysis was carried out by flow cytometry. Without immunosuppressive therapy expression of IL2 receptors only on T cells (CD5) was significantly increased as shown by double staining (11.9% +/- 7.8% vs 2.1% +/- 1% in controls). After 2-3 weeks under immunosuppressive treatment with prednisolone and azathioprine, however, BP lymphocytes did not exhibit any IL2 receptors. PBLs of 18 BP patients showed an increase in IL2 production (1027.4 +/- 670.5 U/ml vs 270 +/- 100 U/ml in controls) during the acute stage of the disease after stimulation with phytohaemagglutinin (PHA)/phorbol myristate acetate (PMA). On the contrary, IL2 production of the same cells in five patients was only in the lowest range of control values after PHA stimulation without PMA (12.5 +/- 29.6 U/ml vs 40 +/- 20 U/ml in controls). Under treatment with immunosuppressants the IL2 production normalized after PHA/PMA stimulation and slightly decreased following PHA stimulation. From these results we conclude that a T-cell activation via activation antigens, as IL2 receptors, and the production of the specific ligand, IL2, may play a role in the pathogenesis of bullous pemphigoid, especially in the earliest stages, and serve as a marker of disease activity.

Interleukin cascade reaction inhibition by supernatants of the cultures of antibody-transformed human basal keratinocytes

We investigated the ability of normal human basal keratinocytes, treated with antibodies against basal keratinocytes, to produce an effect upon the activity of allogenic peripheral blood mononuclear cells. We determined the influence of basal keratinocyte culture supernatants (BKCS) upon the mononuclear cell ability for proliferation in the response to PHA and Con A, for IL 1 and IL 2 production as well as for absorption of exogenous IL 2. It was found that BKCS inhibit the lectin-dependent transformation of mononuclears and interleukin cascade reactions. The conclusion was made about the capacity of antibody-transformed basal keratinocytes for down regulation of immune-response as well as about the role of antibodies in feedback interactions between interleukin-induced antibody synthesis and interleukin production.

Bullous pemphigoid

Bullous pemphigoid is an autoimmune blistering dermatologic disease characterized clinically by tense bullae that may develop on normal or erythematous skin. The major histologic feature is a subepidermal blister with variable degrees of dermal inflammation. Other immunologically mediated blistering skin diseases may mimic bullous pemphigoid, including herpes gestationis, cicatricial pemphigoid, dermatitis herpetiformis, and epidermolysis bullosa acquisita. These diseases will be discussed. Most patients with bullous pemphigoid demonstrate circulating autoantibodies reactive with an antigen located in the lamina lucida region of the basement membrane zone. Complement activation by these autoantibodies initiates influx and activation of mast cells along with other inflammatory cells. Tissue injury with damage and eventual destruction of the basement membrane occurs as a result of the release of inflammatory mediators. The final result is subepidermal blister formation. The course of bullous pemphigoid tends to be self-limited, and successful treatment is usually effected with systemic glucocorticosteroids.