Health Care Utilization and Clinical Management of All-Cause and Norovirus-Associated Acute Gastroenteritis Within a US Integrated Health Care System

Background

Norovirus-associated acute gastroenteritis (AGE) exacts a substantial disease burden, yet the health care utilization for and clinical management of norovirus-associated AGE are not well characterized.

Methods

We describe the health care encounters and therapeutics used for patients with all-cause and norovirus-associated AGE in the Kaiser Permanente Northwest health system from 1 April 2014 through 30 September 2016. Medical encounters for patients with AGE were extracted from electronic health records, and encounters within 30 days of one another were grouped into single episodes. An age-stratified random sample of patients completed surveys and provided stool samples for norovirus testing.

Results

In total, 40 348 individuals had 52 509 AGE episodes; 460 (14%) of 3310 participants in the substudy tested positive for norovirus. An overall 35% of all-cause AGE episodes and 29% of norovirus-associated AGE episodes had ≥2 encounters. While 80% of norovirus-associated AGE episodes had at least 1 encounter in the outpatient setting, all levels of the health care system were affected: 10%, 22%, 10%, and 2% of norovirus-associated AGE episodes had at least 1 encounter in virtual, urgent care, emergency department, and inpatient settings, respectively. Corresponding proportions of therapeutic use between norovirus-positive and norovirus-negative episodes were 13% and 10% for intravenous hydration (P = .07), 65% and 50% for oral rehydration (P < .001), 7% and 14% for empiric antibiotic therapy (P < .001), and 33% and 18% for antiemetics (P < .001).

Conclusions

Increased health care utilization and therapeutics are likely needed for norovirus-associated AGE episodes during peak norovirus winter seasons, and these data illustrate that effective norovirus vaccines will likely result in less health care utilization.

Subacute cutaneous lupus erythematosus and dermatomyositis associated with anti-programmed cell death 1 therapy

Programmed cell death 1 (PD-1) blockade has rapidly emerged as an effective therapy for a wide variety of metastatic malignancies. It has been associated with multiple immune-related adverse effects, including cutaneous eruptions. We describe two patients with clinical and histological findings that were consistent with subacute cutaneous lupus erythematosus (SCLE) after receiving PD-1 inhibitor therapy for metastatic lung cancer. We successfully treated our first patient with systemic and topical steroids, photoprotection and hydroxychloroquine. However, he subsequently developed dermatomyositis after continuing PD-1 inhibitor therapy. Our second patient presented with a protracted course of a cutaneous eruption in spite of discontinuation of anti-PD-1 therapy and treatment with systemic corticosteroids and infliximab. This patient's SCLE resolved after the addition of topical steroids and photoprotection and discontinuation of anti-tumour necrosis factor therapy. She and her oncology team decided to pursue non-PD-1 inhibitor treatment for lung cancer owing to a lack of tumour response. We add SCLE and dermatomyositis to the growing list of autoimmune complications of PD-1 blockade. Our cases raise a number of questions, particularly in relation to the viability of continuing anti-PD-1 therapy after developing SCLE and the role of immunosuppressive therapy in patients with PD-1 inhibitor-associated connective tissue disease. What's already known about this topic? Programmed cell death 1 (PD-1) blockade, which is rapidly emerging as a therapy for a wide variety of metastatic malignancies, has been associated with multiple immune-related adverse effects. These include systemic autoimmune diseases such as colitis and thyroiditis in addition to numerous cutaneous adverse events. Cutaneous side-effects of PD-1 inhibitors most commonly reported in clinical trials include lichenoid reactions, eczematous dermatitis and vitiligo. What does this study add? We report two cases of PD-1 inhibitor-associated subacute cutaneous lupus erythematosus (SCLE), with one patient progressing to dermatomyositis with continued PD-1 inhibitor treatment. In addition to being a novel cutaneous adverse event, we also demonstrate the possibility of development of multiple autoimmune diseases in one patient, which is different from classic drug-related SCLE. We discuss the treatment challenges for patients with autoimmune skin disease receiving PD-1 inhibitor therapy.

Should all patients undergoing treatment with biologic agents be screened annually for latent tuberculosis infection with an interferon gamma release assay?

Systemic biologic therapy has become commonplace for the treatment of a variety of inflammatory dermatologic conditions, particularly psoriasis. Screening for latent tuberculosis infection (LTBI) is recommended prior to initiation of systemic biologic agents, and an interferon gamma release assays (IGRA) is often used as the screening modality. Annual screening for LTBI is also recommended for patients while on systemic biologic therapy, but the literature does not clearly support how often screening should be performed. In addition, serial testing with IGRAs, particularly among low-risk populations without any new tuberculosis (TB) exposures, has proven to be unreliable with frequent reversions and conversions. We propose that in low-incidence TB regions, repeat LTBI screening should only be considered for patients on systemic biologic therapy if any new TB exposures occurred since initial LTBI screening was performed prior to starting biologic therapy. This strategy aims to reduce false-positive LTBI testing that can expose patients to hazardous antibiotics and result in the unnecessary interruption of systemic biologic therapy.

A multicentre randomized trial of the treatment of patients with pemphigus vulgaris with infliximab and prednisone compared with prednisone alone

BACKGROUND

Pemphigus vulgaris (PV) is a blistering disease and tumour necrosis factor-α has a role in its pathogenesis.

OBJECTIVES

To evaluate the safety of infliximab (IFX) with prednisone compared with prednisone alone in the treatment of PV. In addition, treatment response was assessed and mechanistic studies were performed.

METHODS

Subjects with PV who had ongoing disease activity while being maintained on prednisone were randomized to receive either IFX or placebo in addition to prednisone. Response status and immunoglobulin (Ig) G anti-desmoglein (Dsg)1 and Dsg3 antibodies were assessed at 18 and 26 weeks.

RESULTS

Ten subjects were randomized to each group. There were no safety signals during the course of the study. At week 18, one subject in each group had responded. At week 26, three IFX-treated subjects vs. none in the placebo group had responded (P = 0·21). At weeks 18 and 26, the median IgG anti-Dsg1 and anti-Dsg3 levels were lower in the IFX-treated patients [IgG anti-Dsg-1 (week 18, P = 0·035; week 26, P = 0·022); IgG anti-Dsg3 (week 18, P = 0·035; week, 26 P = 0·05)].

CONCLUSIONS

This study is limited by the relatively small sample size. There was no significant difference between study arms in the proportion of subjects with treatment-related adverse events > grade 3. IFX therapy was not shown to be effective for the treatment of patients with PV in this randomized, placebo-controlled trial, although IFX treatment may be associated with a decrease in anti-Dsg1 and Dsg3 antibodies.

Effects of Y27632 on keratinocyte procurement and wound healing

A number of Rho-kinase inhibitors have been developed for various clinical applications. We examined the effects of the Rho-kinase inhibitor Y27632 on keratinocyte proliferation and migration, and found that it promoted primary human keratinocyte proliferation and migration in both monolayer and skin explant cultures. In addition, topical application of Y27632 enhanced cutaneous wound closure in the majority of wounds in mice. The growth and migration effects of Y27632 appeared to be specific to keratinocytes compared with dermal fibroblasts, and required intact Jun kinase function. Y27632 seems to be a promising agent for keratinocyte procurement and wounding healing.

Neutrophil CD11b, L-selectin and Fc IgA receptors in patients with dermatitis herpetiformis

BACKGROUND

The skin lesions found in patients with dermatitis herpetiformis (DH) are characterized by the presence of neutrophils at the dermal papillary tips in areas where the diagnostic cutaneous IgA deposits are found. Although the presence of the skin lesions of DH is known to be associated with gluten-sensitive enteropathy, the mechanisms that control the development of skin lesions are not known.

OBJECTIVES

To determine if circulating neutrophils from patients with DH have evidence of priming as shown by increased expression of CD11b, decreased expression of L-selectin and increased function of neutrophil Fc IgA receptor.

METHODS

Neutrophils from 12 normal subjects and 10 DH patients with active, ongoing disease and 14 DH patients with quiescent disease activity were examined by fluorescence-activated cell sorter for expression of cell surface CD11b, L-selectin expression, Fc IgA expression (CD89) and for the function of the Fc IgA receptor by determining the binding capacity of neutrophils for monoclonal human IgA.

RESULTS

Neutrophils from patients with active, ongoing DH had increased expression of CD11b when compared with patients with inactive DH or normal subjects [mean net geometric mean channel fluorescence (GMCF): active DH, 403.3; inactive DH, 237.8; normal subjects, 290.5; P < 0.05]. L-selectin expression in both groups of DH patients was significantly lower than that seen in normal subjects (mean net GMCF: active DH, 363.2; inactive DH, 375.2; normal subjects, 432.7; P < 0.05). No difference in CD89 expression was seen in any of the groups; however, the function of Fc IgA receptor was increased in patients with active DH when compared with patients with inactive DH and normal subjects.

CONCLUSIONS

Neutrophils from patients with active, ongoing DH show an increased expression of CD11b, decreased expression of L-selectin and increased ability to bind IgA, consistent with a pattern of priming of the neutrophils. This priming may occur in the gut as a result of the ongoing mucosal immune response that is present in patients with DH on a gluten-containing diet and may predispose neutrophils to localize in the skin of patients with DH.

Combination treatment of bullous pemphigoid with anti-CD20 and anti-CD25 antibodies in a patient with chronic graft-versus-host disease

In this case report we describe a novel treatment with two chimeric monoclonal antibodies (MoAb) targeting the autoimmune B cell clone responsible for bullous pemphigoid (BP) as a manifestation of steroid refractory chronic graft-versus-host disease (GVHD) that developed after unrelated cord blood transplantation. Monitoring the BP-specific circulating antibodies and CD25-expressing activated T lymphocyte subset led us to combine anti-CD20 (Rituximab) mediated B cell ablation with anti-CD25 (Daclizumab) therapy to block CD4(+) T cell help. Complete clinical and serologic response was achieved within 4 weeks of initiation of therapy allowing global immunosuppression to be dramatically reduced.

Increased production of IL-4 by gut T-cell lines from patients with dermatitis herpetiformis compared to patients with isolated gluten-sensitive enteropathy

Dermatitis herpetiformis (DH) and isolated gluten-sensitive enteropathy (GSE) are gluten-sensitive diseases in which ingestion of dietary gluten results in the development of clinical disease. Patients with DH develop cutaneous IgA deposits and a severe skin disease, but rarely develop gastrointestinal symptoms. Patients with isolated GSE develop clinically significant gastrointestinal symptoms, but not skin disease or cutaneous IgA deposits. The aim of this study was to investigate the mechanism by which a mucosal immune response to the same dietary antigen can result in two distinct clinical phenotypes. T-cell lines were derived from activated T-cells in the small bowel mucosa of five patients with DH and 14 patients with isolated GSE and analyzed for T-cell markers and cytokine production in vitro. T-cell lines from DH and isolated GSE patients produced IFN-gamma after stimulation (mean: DH = 2,619 pg/ml; isolated GSE = 1,993 pg/ml; NS). T-cell lines from patients with DH, however, produced significantly more IL-4 than the T-cell lines from patients with isolated GSE (IL-4: DH = 2,010 pg/ml; isolated GSE = 235 pg/ml; P < 0.05). Analysis of intracytoplasmic cytokine production by the T-cell lines showed that T-cell lines from patients with DH were CD4+ predominant, with a greater proportion of CD4+/IL4+ cells than CD4+/IFN-gamma+ cells. In contrast, isolated GSE T-cell lines were predominantly CD8+, with an equal proportion of IL-4- and IFN-gamma-positive cells. These studies demonstrate that T cell lines from patients with DH produce significantly more IL-4 than T-cell lines from patients with isolated GSE, while producing similar amounts of IFN-gamma. This difference in cytokine pattern may play an important role in the different clinical manifestations of these two forms of gluten sensitivity.

TCR Vbeta expression in the small bowel of patients with dermatitis herpetiformis and gluten sensitive enteropathy. Limited expression in dermatitis herpetiformis and treated asymptomatic gluten sensitive enteropathy

Dermatitis herpetiformis (DH) is a blistering skin disease characterized by cutaneous deposits of IgA and an associated, most often asymptomatic, gluten sensitive enteropathy (GSE). Gluten sensitive enteropathy is also seen in patients that do not have skin disease or cutaneous IgA deposits, but do have significant gastrointestinal (GI) complaints. Patients with DH and with GSE without skin disease have similar small bowel morphologic changes and HLA associations and both the skin disease and the GI symptoms can be controlled by a gluten free diet. It is not known what factors allow almost all patients with DH to continue to eat gluten and not develop symptomatic gastrointestinal disease. We have examined the expression of the Vbeta T-cell receptor (TCR) in the small bowel of patients with DH (n=11) and of patients with both symptomatic (n=10) and asymptomatic (n=7) GSE without skin disease to determine if differences in the pattern of TCR Vbeta expression are associated with differences in the clinical manifestations of these diseases. TCR Vbeta expression was analyzed using RT-PCR from small bowel biopsies. Patients with DH and those with GSE without skin disease that were on a gluten free diet and asymptomatic were found to express 6.6 and 5.6 out of 20 Vbeta families respectively, with no single family preference. Examination of peripheral blood lymphocytes from these patients did not reveal any restriction of TCR Vbeta family expression. In contrast, patients with symptomatic GSE expressed 12.6 Vbeta families (P< 0.05), with no consistent preferential expression of any single Vbeta family between patients. Patients with DH, who are continuing to ingest wheat, show a more restricted pattern of TCR Vbeta utilization, similar to that of treated patients with GSE without skin disease, and significantly different from GSE without skin disease patients eating gluten. These findings suggest that the restricted nature of the TCR Vbeta expression may play a role in the different clinical manifestations of dermatitis herpetiformis and isolated gluten sensitive enteropathy.

The 120-kDa soluble ectodomain of type XVII collagen is recognized by autoantibodies in patients with pemphigoid and linear IgA dermatosis

BACKGROUND

Type XVII collagen promotes adhesion of basal keratinocytes to epidermal basement membrane, and is the target of disease in patients with certain inherited or acquired blistering diseases. Two forms of type XVII collagen are produced by cultured human keratinocytes: a 180-kDa full-length, transmembrane protein, and a recently identified 120-kDa soluble fragment that corresponds to its collagenous ectodomain.

OBJECTIVES

We aimed to determine the incidence and pattern of reactivity of autoantibodies against the 180- and 120-kDa forms of type XVII collagen in sera from 40 patients with bullous pemphigoid (BP), pemphigoid gestationis or cicatricial pemphigoid (CP), as well as six patients with linear IgA dermatosis (LAD).

METHODS

Various immunochemical techniques were used.

RESULTS

These studies found that the 120-kDa fragment of type XVII collagen was bound by circulating autoantibodies in 13 of 38 patients with BP or CP and all six patients with LAD. While many pemphigoid sera had specific reactivity against one but not both forms of this protein, autoantibodies from patients with LAD bound only the soluble ectodomain.

CONCLUSIONS

These findings are consistent with the presence of both neoepitopes and cross-reactive epitopes on the ectodomain of type XVII collagen. The finding that sera from patients with LAD showed specific reactivity to epidermal basement membrane suggests that such neoepitopes are present in human skin and that their targeting by autoantibodies may contribute to disease pathogenesis.

Reliability and accuracy of dermatologists' clinic-based and digital image consultations

BACKGROUND

Telemedicine technology holds great promise for dermatologic health care delivery. However, the clinical outcomes of digital image consultations (teledermatology) must be compared with traditional clinic-based consultations.

OBJECTIVE

Our purpose was to assess and compare the reliability and accuracy of dermatologists' diagnoses and management recommendations for clinic-based and digital image consultations.

METHODS

One hundred sixty-eight lesions found among 129 patients were independently examined by 2 clinic-based dermatologists and 3 different digital image dermatologist consultants. The reliability and accuracy of the examiners' diagnoses and the reliability of their management recommendations were compared.

RESULTS

Proportion agreement among clinic-based examiners for their single most likely diagnosis was 0. 54 (95% confidence interval [CI], 0.46-0.61) and was 0.92 (95% CI, 0. 88-0.96) when ratings included differential diagnoses. Digital image consultants provided diagnoses that were comparably reliable to the clinic-based examiners. Agreement on management recommendations was variable. Digital image and clinic-based consultants displayed similar diagnostic accuracy.

CONCLUSION

Digital image consultations result in reliable and accurate diagnostic outcomes when compared with traditional clinic-based consultations.

Expression of interleukin-4 and interferon-gamma in the small bowel of patients with dermatitis herpetiformis and isolated gluten-sensitive enteropathy

Although possessing a morphologically similar small bowel abnormality to patients with isolated gluten-sensitive enteropathy (GSE), patients with dermatitis herpetiformis (DH) have few gastrointestinal symptoms and exhibit blistering skin lesions and cutaneous IgA deposits. To determine whether clinical discrepancies between these gluten-sensitive conditions might be the result of different patterns of small bowel cytokine expression, duodenal biopsies were obtained from eight DH patients and nine isolated GSE patients. Biopsies were evaluated for interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) expression by reverse-transcriptase polymerase chain reaction (message) and immunohistochemistry (protein). In DH patients, most of whom had no gut symptoms, IFN-gamma mRNA expression was significantly less than in isolated GSE patients with symptomatic gut disease. Conversely, IL-4 mRNA expression in DH patients was greater than that found among isolated GSE patients. These findings suggest that the different clinical phenotypes of gluten sensitivity may be caused by variation in cytokine expression in the small bowel response to gluten.

Characterization of skin cytokines in bullous pemphigoid and pemphigus vulgaris

The purpose of this study was to determine cytokine and cell marker expression in perilesional skin biopsies from patients with the autoimmune blistering diseases bullous pemphigoid (BP, n = 21) and pemphigus vulgaris (PV, n = 7). Immunohistochemistry and in situ hybridization were used to detect T helper (Th)1 [interleukin (IL)-2, interferon (IFN)-gamma] and Th2 (IL-4, IL-5, IL-13) protein and mRNA. Perilesional skin biopsies from patients with BP were characterized by the deposition of IL-4, IL-13 and IL-5. In patients with BP, IL-4 and IL-13 localized to mononuclear cells within the dermal infiltrate while IL-5 was predominately expressed at the dermal-epidermal junction. BP skin sections also expressed vascular cell adhesion molecule 1 on endothelial cells, not seen in patients with PV. PV biopsies were remarkable for a mixed Th1/Th2 pattern of cytokine expression, including the presence of IL-2, IFN-gamma and IL-4 and the absence of IL-5 and IL-13. In situ hybridization detected mRNA for IL-4 and IL-5 in the cellular infiltrate of BP patients, and IL-2 in a patient with PV. In vitro binding assays demonstrated that normal human eosinophils, activated by coculture in IL-5, bound preferentially to BP skin sections that contained detectable in vivo bound IL-5. The predominance of Th2 cytokines in BP, in association with increased binding of eosinophils in vitro, suggests that Th2 cytokines are relevant in the recruitment and adhesion of eosinophils within the dermal infiltrates of patients with BP, and may play a part in the pathogenesis of blister formation.

A pilot trial of digital imaging in skin cancer

We have used inexpensive off-the-shelf equipment for store-and-forward teledermatology and compared the precision and accuracy of digital image consultations with conventional, clinic-based consultations. Thirteen lesions were studied on 12 patients referred to a dermatology clinic for a suspected skin cancer. Patients were examined by two dermatologists. Subsequently, digital images were examined by two different dermatologists. There was almost complete agreement, both among and between the clinical and digital examiners, on different diagnosis and biopsy recommendations. Agreement on the single most likely diagnosis was also good. Digital imaging shows promise in teledermatology.

Characterization of autoantibodies in pemphigus using antigen-specific enzyme-linked immunosorbent assays with baculovirus-expressed recombinant desmogleins

Pemphigus vulgaris (PV) and pemphigus foliaceus (PF) are autoimmune skin diseases caused by autoantibodies against desmoglein (Dsg) 3 and Dsg1, respectively. Routine immunofluorescence testing of skin and serum from patients cannot distinguish between these two severe diseases since both have IgG Abs directed against keratinocyte cell surfaces. In this study, recombinant Dsg3 and Dsg1, produced as secreted proteins by baculovirus expression, have been utilized to develop ELISAs for the specific characterization of their autoantibodies. Of 49 PV sera, 46 were positive in the Dsg3 ELISA and 44 of 46 PF sera were positive in the Dsg1 ELISA, compared with only 3 of 23 sera of bullous pemphigoid, and none of 53 normal control sera in both ELISAs. Both the Dsg3 and Dsg1 ELISAs were more specific and sensitive than conventional immunofluorescence staining. These Ag-specific ELISAs revealed that more than one-half of PV sera (26 of 49) had anti-Dsg1 Abs in addition to anti-Dsg3 Abs. PV patients who had not only oral mucous lesions but also significant skin involvement tended to have higher titers of anti-Dsg1 Abs. Furthermore, the ELISA reactivity correlated well with clinical disease activity in 5 of 6 PV and 5 of 5 PF patients. This ELISA provides a sensitive and highly specific assay for the diagnosis of patients with PV and PF, the correlation of disease activity with serum Ab levels, and a novel tool for investigating the immunopathogenesis of pemphigus.

Characterization of autoantibodies in pemphigus using antigen-specific enzyme-linked immunosorbent assays with baculovirus-expressed recombinant desmogleins

Pemphigus vulgaris (PV) and pemphigus foliaceus (PF) are autoimmune skin diseases caused by autoantibodies against desmoglein (Dsg) 3 and Dsg1, respectively. Routine immunofluorescence testing of skin and serum from patients cannot distinguish between these two severe diseases since both have IgG Abs directed against keratinocyte cell surfaces. In this study, recombinant Dsg3 and Dsg1, produced as secreted proteins by baculovirus expression, have been utilized to develop ELISAs for the specific characterization of their autoantibodies. Of 49 PV sera, 46 were positive in the Dsg3 ELISA and 44 of 46 PF sera were positive in the Dsg1 ELISA, compared with only 3 of 23 sera of bullous pemphigoid, and none of 53 normal control sera in both ELISAs. Both the Dsg3 and Dsg1 ELISAs were more specific and sensitive than conventional immunofluorescence staining. These Ag-specific ELISAs revealed that more than one-half of PV sera (26 of 49) had anti-Dsg1 Abs in addition to anti-Dsg3 Abs. PV patients who had not only oral mucous lesions but also significant skin involvement tended to have higher titers of anti-Dsg1 Abs. Furthermore, the ELISA reactivity correlated well with clinical disease activity in 5 of 6 PV and 5 of 5 PF patients. This ELISA provides a sensitive and highly specific assay for the diagnosis of patients with PV and PF, the correlation of disease activity with serum Ab levels, and a novel tool for investigating the immunopathogenesis of pemphigus.

Primary care clinicians' performance for detecting actinic keratoses and skin cancer

BACKGROUND

If skin cancer screening is to become widely adopted, its effectiveness depends on the ability of primary care clinicians to detect cutaneous malignancies.

OBJECTIVE

To assess primary care clinicians' proficiency for detecting skin cancers and actinic keratoses in a clinic population.

METHODS

A convenience sample of 190 white male patients aged 40 years or older presenting to a university-affiliated Veterans Affairs general internal medicine or dermatology clinic were included in the study. Each patient was independently examined by a primary care clinician and a dermatologist to measure interobserver agreement. We compared the ability of primary care clinicians to diagnose actinic keratoses and skin cancers using dermatologists' examinations as a pragmatic reference standard.

RESULTS

Agreement was moderate as to whether a patient had single actinic keratosis (kappa, 0.36; 95% confidence interval [CI], 0.22-0.50), multiple actinic keratoses (kappa, 0.48; 95% CI, 0.34-0.61), or skin cancer (kappa, 0.48; 95% CI, 0.34-0.62). Agreement decreased when individual lesions were the unit of analysis. When the patient was the unit of analysis, primary care clinicians identified the presence of skin cancer with a sensitivity of 57% (95% CI, 44%-68%), specificity of 88% (95% CI, 81%-93%), positive likelihood ratio of 4.9 (95% CI, 3.0-8.3), and negative likelihood ratio of 0.48 (95% CI, 0.35-0.63). When the lesion was the unit of analysis the sensitivity was 38% (95% CI, 29%-47%), the specificity was 95% (95% CI, 93%-96%), the positive likelihood ratio was 7.1 (95% CI, 4.8-10.3), and the negative likelihood ratio was 0.66 (95% CI, 0.56-0.75).

CONCLUSIONS

Examinations performed by primary care clinicians for diagnosing skin cancer lacked sensitivity. Without improved diagnostic skills, primary care clinicians' examinations may be ineffective as a screening test.

Comparative epitope mapping of sera from United States (US) and Japanese patients with bullous pemphigoid (BP) to fusion proteins encoded by BPAG1

Sera from patients with bullous pemphigoid (BP) from the United States (US), Japan, and Britain demonstrate similar reactivity to the major target antigens BPAG1 and BPAG2. The purpose of the present study was to determine if the epitope specificity of circulating autoantibodies in patients with BP from the US and Japan is similar as mapped by binding to fusion proteins encoded by BPAG1. Sera from patients and controls with BP from the US and Japan were assayed for reactivity to intact BPAG1 and BPAG2 by immunoblot, and to fusion proteins encoded by BPAG1 by immunoblot and enzyme-linked immunosorbant assay (ELISA). Significant reactivity to fusion proteins encoded by the carboxyl region (FP 16-8) and coiled-coil region (FP3) was seen in sera from the US and Japanese patients, but not from normal controls from the US or Japan. Sera from US and Japanese patients differed in their response to FP7; namely, the reactivity of sera from US patients but not from Japanese patients to FP7 was significantly different from the reactivity of their respective control sera. The reasons for this difference in reactivity are unknown but may reflect genetic or environmental factors relevant in the generation of an autoantibody response to these target antigens.

The influence of history on interobserver agreement for diagnosing actinic keratoses and malignant skin lesions

BACKGROUND

Quantifying interobserver diagnostic agreement is necessary to evaluate skin cancer screening programs, but estimates of variability are incomplete.

OBJECTIVE

We sought to measure agreement between dermatologists for diagnosing actinic keratoses (AKs) and malignant skin lesions and to determine the way in which blinding examiners to patient history affects agreement.

METHODS

We varied the amount of historical information available to examiners in two consecutive patient series (n = 50) presenting to a Veterans Affairs Medical Center dermatology clinic. Two dermatologists examined each patient independently.

RESULTS

Assessing historical features increased the kappa statistic for malignancy recognition from -0.04 to 0.76. kappa Statistics for diagnosing single AKs were 0.17 and 0.15, respectively, and 0.62 and 0.55 for multiple AKs.

CONCLUSION

Agreement was high for diagnosing malignant skin lesions when history was included in the evaluation. Agreement for multiple AKs was higher than for single AKs, although neither was influenced by inclusion of historical features.

Peripheral blood mononuclear cells from patients with bullous pemphigoid have an increased frequency of response to synthetic peptides encoded by BPAG1

We determined the response of peripheral blood mononuclear cells from patients with bullous pemphigoid and normal subjects to synthetic peptides encoded by BPAG1. Peripheral blood mononuclear cells from patients and normal subjects were cocultured in the presence of 15-22-amino-acid-long amphipathic and hydrophilic peptides selected from the BPAG1 sequence. Seven of 10 patients (70%) with bullous pemphigoid had an increased response of peripheral blood mononuclear cells (> 3.25/10(6) cells) when cultured with amphipathic sequences encoded by BPAG1 compared to 3 of 10 (30%) normal subjects. Peripheral blood mononuclear cells from 3 of 15 (20%) patients and 3 of 15 normal subjects (20%) demonstrated an increased response when cultured with hydrophilic peptides. Peptides associated with an increased peripheral blood mononuclear cell response in patients with bullous pemphigoid were adjacent to regions of BPAG1 recently demonstrated to contain epitopes recognized by circulating autoantibodies in the sera of patients with bullous pemphigoid. Increased peripheral blood mononuclear cell responses were more commonly observed in patients with bullous pemphigoid with generalized disease and those who had their disease for longer than 2 months (p < 0.05). The observation that increased duration and generalized disease was associated with increased peripheral blood mononuclear cell responses to peptides encoded by BPAG1 supports the hypothesis that responses to BPAG1 may occur as a consequence of ongoing inflammation at the basement membrane.

Cross-reactive idiotypes in the sera of patients with bullous pemphigoid express anti-basement-membrane-zone activity

We have previously generated a monoclonal anti-idiotypic antibody (antiId 3-17) specific for a cross-reactive idiotype (CRI) present in sera and bound at the basement membrane zone (BMZ) in some patients with bullous pemphigoid (BP). The purpose of the present study was to determine if CRI isolated from sera of patients with BP expressed anti-BMZ activity. CRI, isolated by affinity chromatography from 5 nonrelated patients with BP, bound to the epidermal side of normal human split skin as detected by indirect immunofluorescence. In patients with BP, the presence of the CRI on circulating IgG is associated with anti-BMZ activity.

IgA antibodies against reticulin and endomysium in the serum and gastrointestinal secretions of patients with dermatitis herpetiformis

Although IgA is present in the skin of patients with dermatitis herpetiformis (DH), the relationship of that IgA to the mucosal immune response is not known. The purpose of this study was to determine if IgA antibodies directed against tissue antigens, which are present in the serum of patients with DH, are also present in the gut secretions of these patients. Serum and gut secretions from 8 patients with DH and 5 control subjects were analyzed by indirect immunofluorescence for the presence of IgA antireticulin and antiendomysium antibodies. IgA antibodies against reticulin (3 of 8 patients) and endomysium (4 of 8 patients) were found in the serum of patients with DH. IgA antibodies were also present in the gut secretions of all of these patients, but not in subjects (patients with DH and controls) that did not have serum IgA antireticulin or antiendomysium antibodies. The presence of IgA antireticulin and antiendomysium in both the serum and gut secretions of DH patients suggests that these antibodies arise as a result of the mucosal immune response and that IgA of mucosal origin can persist in the serum of patients with DH.

IgG antibodies from patients with bullous pemphigoid bind to fusion proteins encoded by BPAg1 cDNA

Bullous pemphigoid (BP) is an autoimmune blistering skin disease characterized in part by the presence of circulating and tissue-bound IgG antibodies directed against the epidermal basement membrane zone. IgG from over 95% of patients with BP have been shown to immunoprecipitate a 230-kD epidermal protein, BPAg1, which has been cloned and sequenced. Although sera from almost all patients with BP react with the 230-kD BP antigen the specific epitope(s) of BPAg1 that IgG binds is not known. We have generated fusion proteins from the 230-kD BP antigen cDNA and analyzed sera from patients with BP for binding to these fusion proteins by immunoblot. Sera from 21 of 30 (70%) patients with BP reacted with FP3A (amino acid 873-1193) compared to four of 13 (30%) normal subjects (p < 0.02). Sera from 10 of 30 (33%) patients reacted with FP7 (AA1623-1812) and to FP3 (AA1003-1193), compared to one of 22 (5%) and 0 of 19 (0%) controls, respectively. No significant reactivity was noted against two other fusion proteins (FP6, FP9). Twenty-four of 30 (80%) patients with BP reacted to at least one of three fusion proteins (FP3, FP3A, FP7) compared to three of 11 (27%) of the control subjects (p < 0.003). Fusion proteins FP3, FP3A, and FP7 are at the amino- or carboxyl-terminal regions of the putative central alpha-helical coiled-coil rod domain of BPAg1, which has been postulated to be involved in the self-aggregation of BPAg1. These findings demonstrate that patients with bullous pemphigoid react with multiple regions of BPAg1 and suggest that part of the pathologic consequences of these auto-antibodies in patients with bullous pemphigoid may be by the disruption of the normal self-aggregation of the BPAg1.

Rabbits immunized with a peptide encoded for by the 230-kD bullous pemphigoid antigen cDNA develop an enhanced inflammatory response to UVB irradiation: a potential animal model for bullous pemphigoid

Previous attempts to develop an animal model of bullous pemphigoid (BP) have failed to result in inflammatory disease in the skin. P1-2 is an 18-amino acid peptide encoded for by the 230-kD BP antigen cDNA that has been shown to contain an epitope recognized by circulating antibodies from patients with BP. The purpose of this study was to determine if ultraviolet B irradiation of rabbits after immunization with the P1-2 peptide would result in an enhanced inflammatory response in the skin to that injury. Three rabbits were immunized with either P1-2 or a control peptide. All rabbits immunized with P1-2, and none of the control rabbits, developed antibodies against P1-2 that bound in vitro to both human and rabbit skin in a linear pattern at the basement membrane zone. Immunized rabbits were irradiated on the flank with ultraviolet light. Rabbits immunized with P1-2 developed an enhanced inflammatory reaction to ultraviolet B irradiation leading to epidermal necrosis and sloughing of some sites in 6-9 d. Control rabbits showed only mild erythema without sloughing, which healed in 4-6 d. Histology in the P1-2 immunized rabbits at 24 h revealed an inflammatory infiltrate of neutrophils at the dermal-epidermal junction, whereas control rabbits showed only mild edema and a sparse inflammatory infiltrate. All the rabbits immunized with P1-2 had linear deposits of immunoglobulin G and C3 at the basement membrane zone of healed skin compared to none of the controls. These findings demonstrate that antibodies against a synthetic peptide encoded by the BP antigen 1 sequence can lead to an enhanced inflammatory response after epithelial injury in rabbit skin.

Expression of cross-reactive idiotypes at the basement membrane zone in patients with bullous pemphigoid

The purpose of the present study was to determine whether tissue-bound anti-basement membrane zone (BMZ) autoantibodies in patients with bullous pemphigoid (BP) express a cross-reactive idiotype. We assayed 34 skin biopsies from 26 patients with BP and nine biopsies from control subjects, including normal subjects and patients with epidermolysis bullosa acquisita for the presence of a cross-reactive idiotype at the BMZ. Perilesional split-skin biopsies were assayed for the presence of immunoreactants, immunoglobulin G, and complement and for reactivity with a monoclonal anti-idiotypic antibody specific for a circulating anti-BMZ antibody, anti-Id 3-17. Anti-Id 3-17 bound in a linear band to the BMZ in 12 of 26 patients with BP (46%) and in 0 of 9 control subjects. In serial biopsy specimens, the presence or absence of cross-reactive idiotype at the BMZ in six patients was stable during the disease course. This cross-reactive idiotype has been previously identified in the serum of 36% of patients with BP; however, in this study, no correlation was noted between the presence of the cross-reactive idiotype in skin and serum of individual patients. Because cross-reactive idiotypes occur as a consequence of restricted variable-region gene utilization, the demonstration of a cross-reactive idiotype at the BMZ previously identified in the serum of patients with BP supports the hypothesis that circulating and tissue-bound autoantibodies in this disease arise from a common genetic origin.

Vancomycin-associated linear IgA dermatosis. A report of three cases

BACKGROUND

Linear IgA dermatosis is an autoantibody-mediated, subepidermal blistering disease that is rarely associated with drug exposure.

OBJECTIVE

We report the development of linear IgA dermatosis in three patients associated with the administration of vancomycin and further characterize the immunopathology.

METHODS

Direct and indirect immunofluorescence assays were performed to characterize the immunoreactants, determine the subclass of the IgA deposits, and map the site of antibody deposition.

RESULTS

A subepidermal blistering disease developed in all patients shortly after vancomycin was initiated, which resolved on discontinuation of the drug. Immunofluorescence studies revealed linear deposits of IgA1 only at the basement membrane zone, below the lamina lucida. Circulating IgA anti-basement membrane zone antibodies were not detected.

CONCLUSION

Three patients had linear IgA dermatosis in association with the administration of vancomycin. All patients had linear deposits of IgA1 localized to the sublamina densa zone. Immunophenotypically, the disease in these patients mimics the pattern of IgA deposits seen in the majority of patients with idiopathic linear IgA dermatosis.

Comparison of the intestinal and serum antibody response in patients with dermatitis herpetiformis

Dermatitis herpetiformis (DH) is an intensely pruritic, blistering skin disease characterized by cutaneous IgA deposits and an associated, most often asymptomatic, gluten-sensitive enteropathy. When patients with DH are placed on a gluten-free diet both the intestinal abnormality and the cutaneous manifestations of the disease are controlled, suggesting that a mucosal immune response is important in the pathogenesis of DH. Although patients with DH continue to ingest gluten only 40-50% have evidence of an ongoing mucosal immune response in their serum. In order to investigate directly the mucosal immune response in patients with DH the antibody response to dietary antigens was analyzed in intestinal secretions and compared to that found in the serum. Intestinal secretions from six patients with DH and five normal subjects were collected using an intestinal lavage solution and analyzed for total IgA, IgG, IgM, and IgA subclasses, and for IgG, IgA, and IgM antibodies against the dietary antigens bovine beta-lactoglobulin and gliadin. Intestinal secretions from patients with DH contained more IgA than those from normal subjects (mean total IgA: DH = 2.3 mg/ml; normal subjects (NL) = 0.143 mg/ml, P = 0.017). This increase in IgA in intestinal secretions from patients with DH was composed primarily of IgA1 (intestinal IgA: 86% IgA1, 14% IgA2; NL gut secretions: IgA1 = 54%; IgA2 = 46%). Increased IgA antibodies directed against beta-lactoglobulin and gliadin were detected in gut secretions of two of six patients with DH and in none of the normal subjects. Serum IgA antibodies against beta-lactoglobulin and gliadin were detected only in the two subjects who had detectable IgA antibodies in their intestinal secretions. Serum and intestinal IgA anti-beta-lactoglobulin antibodies had similar isoelectric spectrotypes (pI 5.0-6.5), IgA subclass composition, and antigenic reactivity by immunoblot analysis, demonstrating the close relationship between the serum and intestinal IgA antibodies. These data demonstrate that in patients with DH an ongoing mucosal immune response is present in the gut as evidenced by a significantly increased concentration of IgA, predominately IgA1. The strong correlation between detectable serum and intestinal IgA antibodies against dietary antigens demonstrates that the lack of serum IgA antibodies against dietary antigens in some patients with DH is not due to the presence of "blocking" IgA anti-dietary antigen antibodies in intestinal secretions.(ABSTRACT TRUNCATED AT 400 WORDS)

Immunogenetics of dermatitis herpetiformis

Dermatitis herpetiformis (DH) is a pruritic, papulovesicular skin disease characterized in part by the presence of granular deposits of IgA at the dermal-epidermal junction, an associated gluten sensitive enteropathy (GSE), and a strong association with specific human histocompatibility leukocyte antigens (HLA). Initial investigations revealed that 60% to 70% of patients with DH expressed the HLA antigen B8 (normal subjects = 21%). Further investigation of the HLA associations seen in patients with DH has revealed an even higher frequency of the HLA class II antigens HLA-DR3 (DH = 95%; normal = 23%), HLA-DQw2 (DH = 100%; normal = 40%), and HLA-DPw1 (DH = 42%; normal = 11%). Analysis of the genetic linkage of HLA antigens has revealed that the strongest HLA association in patients with DH is with the HLA class II antigens DR3 and DQw2. This article will discuss current studies regarding the role of HLA associations and DH and the role this strong HLA association may play in the pathophysiology of DH.

Soluble interleukin-2 receptor levels in patients with dermatitis herpetiformis

To determine the role of T-cell activation in dermatitis herpetiformis (DH), soluble IL-2R levels were measured by enzyme-linked immunosorbent assay (ELISA) in the sera of 30 patients with DH. Levels of this shed receptor are considered to be a measure of in vivo T-lymphocyte activation, and are elevated in the sera of many patients with inflammatory and immune-mediated diseases. Fifteen of the thirty (50%) patients with DH had elevated levels of soluble IL-2R compared to one of 31 (3%) healthy HLA-B8 or HLA-DR3 control subjects (p less than 0.00001) and one of 10 (10%) healthy non-HLA-B8/-DR3 subjects (p less than 0.0018). In addition, the mean soluble IL-2R level in the patients with DH (744 +/- 381 U/ml) was also significantly higher than that seen in 31 healthy HLA B8 or HLA DR3 individuals (388 +/- 160 U/ml, p = 0.0001) and 10 healthy non-HLA-B8/DR3 individuals (397 +/- 201 U/ml, p = 0.002). Only two of the 30 patients with DH had active skin lesions at the time of serum sampling, one of whom had elevated levels of IL-2R. Measurement of soluble IL-2R levels in sequential serum samples, available in four patients with DH at times of active and inactive skin disease, demonstrated a temporal association between soluble IL-2R level elevations and active skin disease in two patients and no association in two patients. In one patient a marked elevation in soluble IL-2R levels occurred with the onset of gastrointestinal symptoms, which decreased by 14% with institution of a gluten-free diet. In order to determine if soluble IL-2R levels are related to the mucosal immune response, the IL-2R levels were compared to the level of IgA antibodies directed against the dietary antigen beta-lactoglobulin. Ten of eleven (91%) patients with circulating IgA anti-beta lactoglobulin antibodies were also found to have elevated levels of IL-2R. In contrast, in the patients with no detectable IgA anti-beta lactoglobulin antibodies, only four of 16 (25%) had elevated levels of IL-2R (p = 0.001). Because IL-2R levels are not related to activity of the skin disease in patients with DH but are associated with the presence of IgA antibodies against the dietary antigen beta-lactoglobulin, these results suggest that some of the T-cell activation commonly present in DH reflects an ongoing immune response in the gastrointestinal tract.

DNA sequence analysis and restriction fragment length polymorphism (RFLP) typing of the HLA-DQw2 alleles associated with dermatitis herpetiformis

Dermatitis herpetiformis (DH) is a blistering autoimmune skin disease associated with a 95-100% incidence of the HLA class II antigen HLA-DQw2. Although the precise role of this antigen in the pathogenesis of DH is unclear, one theory proposes that patients with DH possess a molecularly unique subtype of the HLA-DQw2 antigen that causes immune abnormalities eventuating in the clinical manifestations of DH. To test this hypothesis, we performed DNA sequence analysis on the highly polymorphic HLA-DQB1 and HLA-DQA1 loci of eight patients with dermatitis herpetiformis. All DQB1 alleles sequenced were identical to the previously described HLA-DQB*0201 allele from HLA-DQw2 normal subjects. In addition, DQA1 alleles sequenced were identical to those alleles previously associated with HLA-DQw2 (DQA*0201, DQA*0501). These data document that although HLA-DQw2 appears to be a necessary element in the pathogenesis of DH, the development of DH is not dependent on the presence of a unique HLA-DQw2 antigen. HLA-DQ allelic typing by restriction fragment length polymorphism analysis of PCR-amplified HLA-DQA1 and HLA-DQB1 fragments was also performed in ten patients with DH to determine the allelic distribution among both HLA-DR3 (eight patients) and non-DR3 (two patients) DH patients. At the HLA-DQ beta chain locus, all patients possessed the DQB1*0201 allele. At the HLA-DQ alpha chain locus, all HLA-DR3 patients and one non-DR3 patient displayed a pattern consistent with the DQA1*0501 allele, whereas one non-DR3 patient displayed a pattern consistent with the DQA1*0201 allele. These data document that patients with DH do not express a unique HLA-DQw2 heterodimer, that the HLA-DQw2 molecules present in patients with DH have no DNA sequence differences from those found in normal HLA-DQw2 subjects and therefore that susceptibility to DH is not due to a unique HLA-DQw2 molecule.

Detection of cross-reactive idiotypes in the serum of patients with bullous pemphigoid

To further characterize the circulating antibasement membrane zone (antiBMZ) antibodies present in the sera of patients with bullous pemphigoid (BP), we have generated a mouse monoclonal anti-idiotypic antibody (antiId 3-17) specific for an IgG antiBMZ antibody. AntiId 3-17 is specific for an idiotype expressed on antiBMZ IgG in the serum of a patient with BP, and not expressed on pooled normal human IgG or IgG from patients with other autoimmune skin diseases. AntiId 3-17 binds to non-reduced, but not reduced, antiBMZ IgG on immunoblot, suggesting that the idiotype is composed of a conformational epitope expressed on native antibody. By a competitive inhibition ELISA, antiId 3-17 detects a cross-reactive idiotype (CRI) expressed in 18 of 50 (36%) of the sera of patients with BP, but in the sera of only 1 of 50 (2%) normal blood bank controls (p less than 0.001, Fisher's exact test) and 1 of 12 (8%) patients with pemphigus (p = 0.005). Thus, antiId 3-17 recognizes a public idiotype on a native antiBMZ antibody from a patient with BP, which is expressed in the sera of 36% of the unrelated patients with BP studied.

IgA-binding structures in dermatitis herpetiformis skin are independent of elastic-microfibrillar bundles

Dermatitis herpetiformis (DH) is characterized in part by the presence of granular deposits of IgA in the papillary dermis just beneath the dermal-epidermal junction. The nature of the structures to which IgA binds in DH skin, however, has not been clearly demonstrated. Previous immunoelectron-microscopy studies using the peroxidase-antiperoxidase technique have concluded that the IgA may bind to abnormal elastic microfibrillar bundles. Recently, antibodies have been developed against a major component of the elastic microfibril bundles, fibrillin. In addition, another dermal matrix protein, hexabrachion, has been characterized and found in normal human skin in a distribution similar to the IgA deposits of DH. Utilizing antibodies against fibrillin, hexabrachion, and human IgA and immunoelectronmicroscopy with immunogold staining techniques, we have examined the skin from patients with DH in order to localize the IgA deposits. Normal-appearing skin from five patients with DH exhibited electron-dense patches within the dermis, which were not seen in skin from normal subjects. These structures were sometimes adjacent to the basement membrane zone, but appeared amorphous and without a well-defined fibrillar structure. The electron-dense patches were labeled with anti-human IgA, but not with antibodies to fibrillin or hexabrachion. The anti-IgA antibody did not label the normal basement membrane. These studies confirm the presence of abnormal electron-dense, amorphous structures in the skin of patients with DH. Due to this lack of association with the elastic microfibril bundles and the lack of labeling with antibodies against fibrillin, we suggest that these deposits are distinct from the microfibrillar bundles of elastic tissue and may represent IgA bound to degraded basement membrane or isolated dermal deposits of IgA.

IgG antibodies from patients with bullous pemphigoid bind to localized epitopes on synthetic peptides encoded by bullous pemphigoid antigen cDNA

Bullous pemphigoid (BP) is an autoimmune blistering disease characterized in part by the presence of tissue-bound and circulating antibodies specific for basement membrane zone proteins, the BP Ag. The purpose of the present study was to determine seroreactivity of patients with BP to six nonoverlapping synthetic peptides representing sequences in the carboxyl domain of the recently cloned 230-kDa BP Ag. Sera from 40 patients with BP, 57 normal subjects, and 18 patients with other autoimmune blistering skin diseases were examined in an ELISA for binding to six synthetic peptides varying between 17 and 19 amino acids in length. The binding of IgG from patients with BP to three synthetic peptides, P1-2, P1-1, and P3-1, was significantly different from that seen in the normal controls (p less than 0.001, Fisher's exact test). Affinity-purified anti-P1-2 antibody from a patient with BP bound in a characteristic linear band to the epidermal side of 1 M NaCl split skin and immunoprecipitated the native 230-kDa BP Ag. Serum IgG antibodies from a rabbit immunized with a BP fusion protein that contains the sequences for P1-1 and P1-2, bound on ELISA to P1-2 but not to P1-1. These data suggest that multiple epitopes on the 230-kDa BP Ag are recognized by circulating autoantibodies in patients with this disease, and that an epitope encoded within the synthetic peptide P1-2 is expressed on the native molecule and may be relevant in the generation of an immune response both in man and in an animal model.

IgG antibodies from patients with bullous pemphigoid bind to localized epitopes on synthetic peptides encoded by bullous pemphigoid antigen cDNA

Bullous pemphigoid (BP) is an autoimmune blistering disease characterized in part by the presence of tissue-bound and circulating antibodies specific for basement membrane zone proteins, the BP Ag. The purpose of the present study was to determine seroreactivity of patients with BP to six nonoverlapping synthetic peptides representing sequences in the carboxyl domain of the recently cloned 230-kDa BP Ag. Sera from 40 patients with BP, 57 normal subjects, and 18 patients with other autoimmune blistering skin diseases were examined in an ELISA for binding to six synthetic peptides varying between 17 and 19 amino acids in length. The binding of IgG from patients with BP to three synthetic peptides, P1-2, P1-1, and P3-1, was significantly different from that seen in the normal controls (p less than 0.001, Fisher's exact test). Affinity-purified anti-P1-2 antibody from a patient with BP bound in a characteristic linear band to the epidermal side of 1 M NaCl split skin and immunoprecipitated the native 230-kDa BP Ag. Serum IgG antibodies from a rabbit immunized with a BP fusion protein that contains the sequences for P1-1 and P1-2, bound on ELISA to P1-2 but not to P1-1. These data suggest that multiple epitopes on the 230-kDa BP Ag are recognized by circulating autoantibodies in patients with this disease, and that an epitope encoded within the synthetic peptide P1-2 is expressed on the native molecule and may be relevant in the generation of an immune response both in man and in an animal model.

Dermatitis herpetiformis

The state of our understanding of the pathogenesis of DH relies on the integration of several key characteristics: (1) a high frequency of the HLA antigens HLA-B8, HLA-DR3, and HLA-DQw2, (2) an associated GSE, (3) the resolution of both the skin lesions and gut abnormalities in response to a gluten-free diet, and (4) the presence of granular deposits of IgA in normal and perilesional skin. The role of the HLA class II antigens expressed in patients with DH most likely relates to the afferent or initiating arm of the immune system. The association of the HLA-A1, -B8, -DR3, -DQw2 haplotype with Sjogren's syndrome, chronic hepatitis, Graves' disease, and other presumably immunologically mediated diseases, as well as the evidence that some normal HLA-B8, -DR3 individuals have an abnormal in vitro lymphocyte response to wheat protein and mitogens and have abnormal Fc-IgG receptor-mediated functions, suggests that this HLA haplotype or genes linked closely to it may confer a generalized state of immune susceptibility on its carrier, the exact phenotypic expression of which depends on other genetic or environmental determinants. It also is clear, from the association of DH with GSE and the ability to control the cutaneous manifestations of DH with a gluten-free diet, that the gut disease is a critical factor in the pathogenesis of DH. Several pathogenetic theories about the origin of the cutaneous IgA deposits in DH have been proposed, one of which states that the IgA is produced in the gut mucosa as a response to a dietary antigen or gut epithelial antigen and then cross-reacts with the skin of patients with DH. A second hypothesis is that the IgA produced in the gut binds to an antigen and is deposited in skin as an antigen-antibody complex. Finally, it could be that the gut mucosal abnormality simply allows an unknown antigen access to the central immune system where an IgA antibody is produced that binds to skin. The failure to detect circulating IgA anti-basement membrane zone antibodies in patients with DH suggests that either the structures to which the IgA binds are not present in normal skin without DH, that IgA cannot bind to these structures in vitro, or that the circulating IgA is too scant for detection with conventional methods. Finally, it must be considered that the IgA deposited in DH skin may bind as a result of non-antigen-antibody interactions that cannot be duplicated in vitro.(ABSTRACT TRUNCATED AT 400 WORDS)

Serum interleukin-2 receptor responses to immunization

Serum interleukin-2 receptor (sIL-2R) levels have been used to assess immune activation in inflammatory and infectious illnesses, although the cellular origin of these receptors and the dynamics of their production are not well defined. To investigate the relationship between sIL-2R levels and the degree of immune activation in antigen-specific responses, sIL-2R were measured in healthy individuals after both primary and secondary immunization with keyhole limpet hemocyanin (KLH). Despite induction of strong antibody responses, KLH immunization did not result in consistent elevations of sIL-2R levels, with only one of six subjects developing a substantial (twofold) increase in sIL-2R levels. The absence of sIL-2R elevation after a discrete antigenic stimulus suggests that inflammatory illnesses in which elevated sIL-2R levels have been noted involve more extensive stimulation of immune cells, either in number or in degree, than that present after simple immunization in healthy individuals.

An HLA class II region restriction fragment length polymorphism (RFLP) in patients with dermatitis herpetiformis: association with HLA-DP phenotype

Dermatitis herpetiformis (DH) is characterized in part by an associated gluten-sensitive enteropathy (GSE), and a strong association with the HLA antigens HLA-A1, -B8, -DR3, and -DQw2, essentially identical to that seen in patients with isolated GSE (celiac disease). A 4.0-kb RsaI RFLP has been identified using a DQ beta-chain cDNA and localized to the HLA-DP beta-chain region. This RFLP has been found more frequently in patients with isolated GSE than in normal HLA matched controls. We have analyzed genomic DNA from 24 patients with DH and 15 HLA-matched controls to determine if this 4.0-kb RsaI RFLP was present in patients with DH. Twenty-one of 24 (87%) of patients with DH were found to have this RFLP as compared to 7 of 10 (70%) HLA-DR3, -DQw2 matched control subjects (p = 0.23). Thus, the 4.0-kb RsaI RFLP detected in patients with isolated GSE is also present in patients with DH; however, its frequency in DH patients does not differ significantly from that of HLA matched controls. Family studies of patients with DH revealed that although the 4.0-kb RsaI RFLP segregated with the HLA-A1, -B8, -DR3, -DQw2 haplotype in one family, it did not segregate with this disease-associated haplotype in two other families. In both patient and control populations, this RFLP was associated with HLA-DPw1 or -DPw3 phenotypes; 25 of 26 (96%) HLA-DPw1 or -DPw3 subjects were found to have this RFLP compared to only 1 of 6 (17%) who did not express HLA-DPw1 or -DPw3 (pc = 0.0009). These population and family data suggest that this 4.0-kb RsaI RFLP is primarily associated with the HLA-DPw1, -DPw3 phenotype, rather than the clinical manifestations of DH. These data further document that the strongest association of DH with HLA antigens remains with HLA-DQw2 and HLA-DR3 antigens.

Dermatitis herpetiformis in two American blacks: HLA type and clinical characteristics

Dermatitis herpetiformis is a rare blistering skin disease characterized in part by granular IgA deposits at the dermoepidermal junction, an associated gluten-sensitive enteropathy, and a strong association with the human histocompatibility leukocyte antigen (HLA)-A1 (74% of patients with dermatitis herpetiformis), -B8 (88%), -DR3 (95%), and -DQw2 (100%). Dermatitis herpetiformis is rarely seen in American blacks and some investigators have postulated that this finding may be due to the decreased frequency of HLA-A1 and -B8 in American blacks compared with Caucasians (American blacks: HLA-A1 = 15.3%, HLA-B8 = 10.7%; Caucasian: HLA-A1 = 26.4%, HLA-B8 = 18.3%). This report describes two American blacks with dermatitis herpetiformis and reports the results of HLA typing of these subjects for HLA-A, -B, -C, -DR, and -DQ antigens. HLA typing revealed that neither patient expressed HLA-A1 or -B8; however, both patients did express the class II antigens most frequently seen in dermatitis herpetiformis, HLA-DR3 and -DQw2. Comparison of HLA class II antigen frequency in normal American blacks and Caucasians reveals a similar frequency of HLA-DR3 and -DQw2 (American blacks: HLA-DR3 = 27.6%, HLA-DQw2 = 40.9%; Caucasian: HLA-DR3 = 22.6%, HLA-DQw2 = 32.9%). These data confirm the importance of the HLA class II region in the pathogenesis of dermatitis herpetiformis. In addition, these data suggest that the rare occurrence of dermatitis herpetiformis in American blacks is not due to the decreased frequency of the HLA class I antigens -A1 and/or -B8 but rather is related to differences in the HLA class II region not detected by routine HLA typing.

Alterations in HLA-DP and HLA-DQ antigen frequency in patients with dermatitis herpetiformis

Dermatitis herpetiformis (DH) is associated with a markedly increased frequency of the HLA class II antigens DR3 and DQw2. To investigate a possible role of HLA-DP (or closely associated genes) in the pathogenesis of DH as well as to confirm the previously described alterations of HLA-DR3 and HLA-DQw2 antigen frequency, we have typed 43 patients with DH for HLA-DP, HLA-DQ, and HLA-DR antigens. All patients with DH had typical clinical and histologic features, as well as granular deposits of IgA at the dermal-epidermal junction by direct immunofluorescence. HLA-DR3 was expressed in 41 of 43 (95%) DH patients, whereas HLA-DQw2 was expressed in all 43 (100%). The overall distribution of HLA-DP antigens in patients with DH was significantly different from that seen in all controls and in HLA-DR3 and HLA-DQw2 controls (p less than 0.02). Examination of the frequency of individual DP antigens revealed that HLA-DPw1 was increased (42% of patients with DH vs 11% of all controls and 26% of DR3 positive controls), but this increase was not statistically greater than that expected due to the disequilibrium linkage of DPw1 with DR3/DQw2. Patients with DH, however, did have a statistically significant decreased frequency of DPw2 (14% of patients vs 31% of all controls and 41% of DR3 positive controls) (pc less than 0.05). Studies of three informative families demonstrated that the DPw2 genes of the DH patients were not present on the haplotype thought to carry a DH susceptibility gene (HLA-A1, HLA-B8, HLA-DR3, HLA-DQw2). A role of HLA-DP region genes in the pathogenesis of DH is further suggested by the observation that HLA-DPw1 was expressed in 82% (9 of 11) of DH patients with IgA antibodies against dietary antigens as compared with only 33% (4 of 12) of patients without IgA antibodies. HLA-DP genes or genes closely linked to them may be important in DH either as markers of the disease haplotype or by direct involvement in its pathogenesis.

Epidermal keratinocytes express the adhesion molecule intercellular adhesion molecule-1 in inflammatory dermatoses

Using indirect immunofluorescence assays on frozen tissue sections of skin from healthy subjects and subjects with inflammatory skin diseases, we found that intercellular adhesion molecule-1 (ICAM-1) was expressed in a cell surface pattern on epidermal keratinocytes at the site of lymphoid infiltration in cutaneous dermatoses. ICAM-1 was not expressed on epidermal keratinocytes in noninflamed skin. Its expression was not related solely to epidermal hyperproliferation, as hyperproliferative, tape-stripped epidermis did not express ICAM-1. We have reported previously that ICAM-1 expression on epidermal keratinocytes was upregulated by treatment with interferon gamma and that activated T lymphocytes bound to cultured epidermal keratinocytes in vitro by lymphocyte function associated-1 (LFA-1) molecules on T cells and ICAM-1 on epidermal keratinocytes. Taken together, these data suggest that upregulation of expression of ICAM-1 is an important feature of cutaneous inflammation.

Anti-idiotypic antibodies as vaccine candidates. The immune network

Antibodies specific for determinants within the variable region of an antibody molecule are known as anti-idiotypic antibodies. Anti-idiotypic antibodies specific for determinants within the antigen binding site of the antibody may mimic the original antigen and are said to bear an "internal image" of the antigen. These anti-idiotypic antibodies have been shown in animal studies to function as surrogate antigens in stimulating an immune response and may ultimately be useful therapeutically as vaccines to prevent infectious diseases, to enhance the immune response to neoplasms, and to modulate autoantibody production in autoimmune diseases.