Development of antigen-specific ELISA for circulating autoantibodies to extracellular matrix protein 1 in lichen sclerosus

Lichen sclerosus is a common, acquired chronic inflammatory skin disease of unknown etiology, although circulating autoantibodies to the glycoprotein extracellular matrix protein 1 (ECM1) have been detected in most patients’ sera. We have examined the nature of ECM1 epitopes in lichen sclerosus sera, developed an ELISA system for serologic diagnosis, and assessed clinicopathological correlation between ELISA titer and disease. Epitope-mapping studies revealed that lichen sclerosus sera most frequently recognized the distal second tandem repeat domain and carboxyl-terminus of ECM1. We analyzed serum autoantibody reactivity against this immunodominant epitope in 413 individuals (95 subjects with lichen sclerosus, 161 normal control subjects, and 157 subjects with other autoimmune basement membrane or sclerosing diseases). The ELISA assay was highly sensitive; 76 of 95 lichen sclerosus patients (80.0%) exhibited IgG reactivity. It was also highly specific (93.7%) in discriminating between lichen sclerosus and other disease/control sera. Higher anti-ECM1 titers also correlated with more longstanding and refractory disease and cases complicated by squamous cell carcinoma. Furthermore, passive transfer of affinity-purified patient IgG reproduced some histologic and immunopathologic features of lichen sclerosus skin. This new ELISA is valuable for the accurate detection and quantification of anti-ECM1 autoantibodies. Moreover, the values may have clinical significance in patients with lichen sclerosus

Effect of Temperature on Suppressor Cells in Chicken Spleen Cell Cultures

The plaque forming cell (PFC) response of in vivo primed chicken spleen cells to sheep erythrocytes (SRBC) at 37°C in vitro was much higher when antigen was added on Day 2 of culture than on Day 0, at the initiation of the incubation period. No such difference was observed when the cells were cultured at 40°C, in which case both responses were low. As shown previously the effect of delayed exposure to SRBC at 37°C was due to a disappearance of suppressor T cells in the absence of antigen, which did not occur at 40°C. Addition of concanavalin A on Day 0 could, even in the absence of SRBC, maintain the suppressor cell activity at 37°C. The results suggest that suppressor cell activity is very temperature dependent

Effect of Temperature and Lymphokines on Mixed Lymphocyte and Mitogen Responses of Chicken Lymphoid Cells in Vitro

The effect of temperature on T cell mitogen and mixed lymphocyte responses (MLR) of chicken lymphoid cells in vitro was examined. Responses at 40°C were much higher than at 37°C. This difference did not appear to be due only to faster kinetics of the responses at 40°C. At the lower temperature the MLR could be enhanced by polyethylene glycol (PEG) for spleen cells and by Con A induced lymphokines for peripheral blood cells (PBL). The positive effect of PEG on the chicken spleen cell MLR appeared to be determined at the stimulator cell level. Responses to mitogens at 37°C of both spleen cells and PBL were enhanced by lymphokines

Defective Bursa Regeneration After Irradiation of Young Thymectomized Chickens

The ability of the bursa of Fabricius to regenerate after γ-irradiation and bone marrow reconstitution was examined in chickens thymectomized (TX) immediately after hatching. Irradiation (2 × 500 R) 3 weeks after hatching was followed by impaired bursa regeneration, as judged both by bursa/body weight ratios and by bursa follicle development 3-6 weeks later in TX as compared to control birds. Germinal center formation in the spleen was deficient, and immune responses to sheep erythrocytes (SRBC) and B. abortus (BA) were moderately reduced in the TX as compared to control birds irradiated at 3 weeks but not in TX birds irradiated at 5 weeks of age

Childhood epidermolysis bullosa acquisita: Confirmation of diagnosis by skin deficient in Type VII Collagen, enzyme-linked immunosorbent assay, and immunoblotting

Epidermolysis bullosa acquisita (EBA) is an acquired subepidermal bullous disorder characterized by autoantibodies against Type VII collagen. It usually affects adults; childhood EBA is rare. We describe a 10-year-old girl presenting with recurrent tense blisters predominantly on legs, dorsa of hands and feet accompanied by oral erosions since the age of 5 years. Direct immunofluorescence (IF) microscopy showed linear deposition of IgG and C3 along the basement membrane zone (BMZ); indirect IF microscopy on salt-split skin revealed staining of IgG to the dermal side of the split. The patient's serum did not show BMZ staining in recessive dystrophic epidermolysis bullosa skin deficient for Type VII collagen, thus confirming autoantibody reactivity against Type VII collagen. Circulating antibodies against the immunodominant noncollagenous 1 domain of Type VII collagen were detected by ELISA and immunoblotting studies. The patient was treated with oral corticosteroids and dapsone with good improvement

Photocontact allergic and phototoxic studies of chlorproethazine

Background: Neuriplege (R) cream was available as a non-prescription medication in France until its withdrawal from the market by regulatory authorities in January 2007. Its active ingredient is the phenothiazine chlorproethazine (CPE). Before its withdrawal, we investigated the photocontact allergic and phototoxic potential of Neuriplege (R) cream and CPE. Methods: An in vitro phototoxic study was performed in HaCaT keratinocytes using the neutral red dye phototoxic assay. Phototoxicity and photocontact allergy were assessed in humans by photopatch testing. Results: In vitro, a 1 h incubation of keratinocytes with CPE was approximately 13 times as toxic to the cells in the presence of ultraviolet light compared with incubation with the drug alone. Of two healthy volunteers initially photopatch tested to Neuriplege (R) cream on the arm, one developed a phototoxic reaction. These two volunteers were then photopatch tested to Neuriplege (R) and CPE on the back with seven additional healthy volunteers. Both of the initial study volunteers experienced a photocontact allergic reaction to Neuriplege (R) as is upon this re-exposure. Of the seven volunteers not previously exposed to Neuriplege (R) as is, five developed phototoxic reactions. Conclusions: This study demonstrates the strong phototoxic and photocontact allergic potential of CPE in Neuriplege (R) cream, and supports the decision of the French pharmaceutical regulatory authorities to withdraw it.</p