Serum reactivity in dermatitis herpetiformis: an international multicentre study.

BACKGROUND: Dermatitis herpetiformis (DH) is a rare gluten-induced skin disorder characterized predominantly by IgA autoantibodies against endomysium, tissue transglutaminase (TG2/tTG), epidermal transglutaminase (TG3/eTG) and deamidated gliadin. To date, circulating autoantibody reactivity has not been systematically described. OBJECTIVES: Characterization of serum reactivities in DH. METHODS: This multicentre international study analysed sera from 242 patients with DH taken at the time of initial diagnosis. DH-specific IgA and IgG serum autoantibodies were analysed by indirect immunofluorescence (IF) on monkey oesophagus, and by enzyme-linked immunosorbent assay (ELISA) based on recombinant TG2/tTG, TG3/eTG and deamidated gliadin (GAF3X). RESULTS: IgA indirect IF microscopy on monkey oesophagus revealed the highest reactivity (84.3%; specificity 100%) followed by IgA TG2/tTG ELISA (78.5%, specificity 99.0%), IgA TG3/eTG ELISA (72.7%, specificity 95.0%) and IgA GAF3X ELISA (69.0%, specificity 98.5%). CONCLUSIONS: Serum IgA and IgG autoantibodies against endomysium, TG2/tTG, TG3/eTG and deamidated gliadin are highly prevalent in DH. Indirect IF microscopy on monkey oesophagus (IgA) provides the highest diagnostic accuracy that can be further enhanced by 4.5% when combined with IgA TG2/tTG ELISA.

Diagnosis and management of pemphigus: Recommendations of an international panel of experts.

BACKGROUND: Several European countries recently developed international diagnostic and management guidelines for pemphigus, which have been instrumental in the standardization of pemphigus management. OBJECTIVE: We now present results from a subsequent Delphi consensus to broaden the generalizability of the recommendations. METHODS: A preliminary survey, based on the European Dermatology Forum and the European Academy of Dermatology and Venereology guidelines, was sent to a panel of international experts to determine the level of consensus. The results were discussed at the International Bullous Diseases Consensus Group in March 2016 during the annual American Academy of Dermatology conference. Following the meeting, a second survey was sent to more experts to achieve greater international consensus. RESULTS: The 39 experts participated in the first round of the Delphi survey, and 54 experts from 21 countries completed the second round. The number of statements in the survey was reduced from 175 topics in Delphi I to 24 topics in Delphi II on the basis of Delphi results and meeting discussion. LIMITATIONS: Each recommendation represents the majority opinion and therefore may not reflect all possible treatment options available. CONCLUSIONS: We present here the recommendations resulting from this Delphi process. This international consensus includes intravenous CD20 inhibitors as a first-line therapy option for moderate-to-severe pemphigus.

Granular C3 Dermatosis.

There has been no previous systematic study of bullous skin diseases with granular basement membrane zone deposition exclusively of C3. In this study we collected 20 such patients, none of whom showed cutaneous vasculitis histopathologically. Oral dapsone and topical steroids were effective. Various serological tests detected no autoantibodies or autoantigens. Direct immunofluorescence for various complement components revealed deposition only of C3 and C5-C9, indicating that no known complement pathways were involved. Studies of in situ hybridization and micro-dissection with quantitative RT-PCR revealed a slight reduction in expression of C3 in patient epidermis. These patients may represent a new disease entity, for which we propose the term "granular C3 dermatosis". The mechanism for granular C3 deposition in these patients is unknown, but it is possible that the condition is caused by autoantibodies to skin or aberrant C3 expression in epidermal keratinocytes.

Specific nongluten proteins of wheat are novel target antigens in celiac disease humoral response.

While the antigenic specificity and pathogenic relevance of immunologic reactivity to gluten in celiac disease have been extensively researched, the immune response to nongluten proteins of wheat has not been characterized. We aimed to investigate the level and molecular specificity of antibody response to wheat nongluten proteins in celiac disease. Serum samples from patients and controls were screened for IgG and IgA antibody reactivity to a nongluten protein extract from the wheat cultivar Triticum aestivum Butte 86. Antibodies were further analyzed for reactivity to specific nongluten proteins by two-dimensional gel electrophoresis and immunoblotting. Immunoreactive molecules were identified by tandem mass spectrometry. Compared with healthy controls, patients exhibited significantly higher levels of antibody reactivity to nongluten proteins. The main immunoreactive nongluten antibody target proteins were identified as serpins, purinins, α-amylase/protease inhibitors, globulins, and farinins. Assessment of reactivity toward purified recombinant proteins further confirmed the presence of antibody response to specific antigens. The results demonstrate that, in addition to the well-recognized immune reaction to gluten, celiac disease is associated with a robust humoral response directed at a specific subset of the nongluten proteins of wheat.

Dermatitis herpetiformis sera or goat anti-transglutaminase-3 transferred to human skin-grafted mice mimics dermatitis herpetiformis immunopathology.

Dermatitis herpetiformis (DH) is characterized by deposition of IgA in the papillary dermis. However, indirect immunofluorescence is routinely negative, raising the question of the mechanism of formation of these immune deposits. Sárdy et al. (2002. J. Exp. Med. 195: 747-757) reported that transglutaminase-3 (TG3) colocalizes with the IgA. We sought to create such deposits using passive transfer of Ab to SCID mice bearing human skin grafts. IgG fraction of goat anti-TG3 or control IgG were administered i.p. to 20 mice. Separately, sera from seven DH patients and seven controls were injected intradermally. Biopsies were removed and processed for routine histology as well as direct immunofluorescence. All mice that received goat anti-TG3 produced papillary dermal immune deposits, and these deposits reacted with both rabbit anti-TG3 and DH patient sera. Three DH sera high in IgA anti-TG3 also produced deposits of granular IgA and TG3. We hypothesize that the IgA class anti-TG3 Abs are directly responsible for the immune deposits and that the TG3 is from human epidermis, as this is its only source in our model. These deposits seem to form over weeks in a process similar to an Ouchterlony immunodiffusion precipitate. This process of deposition explains the negative indirect immunofluorescence results with DH serum.

Skin-Related Quality of Life During Autoimmune Bullous Disease Course.

Importance: Autoimmune bullous diseases (AIBDs) are chronic relapsing-remitting conditions with significant morbidity. Skin-related quality of life (SRQL) may vary by AIBD subtype and disease type. Disease severity and flare severity can be difficult to define; SRQL can offer a key insight. Objectives: To investigate the Skindex-16 score as an SRQL measure in AIBD subtypes during flare and nonflare states and to evaluate Skindex-16 construct validity. Design, Setting, and Participants: This retrospective cross-sectional study was conducted from September 1, 2016, to February 1, 2020, among 192 patients at the University of Utah Health autoimmune dermatology clinic with pemphigoid, pemphigus, dermatitis herpetiformis, and linear immunoglobulin A disease. Patients had an encounter-associated diagnosis, Skindex-16 scores, and self-reported flare status. Statistical analysis was performed from March 2022 to June 2023. Exposure: Autoimmune bullous disease subtype and patient-reported flare status. Main Outcomes and Measures: Skindex-16 domain scores (emotions, symptoms, and functioning; range, 0-100, where 0 indicates no effect on SRQL and 100 maximum effect) and individual item scores were described by disease and flare status. Flare scores were expected to be higher by at least the standard error of measurement (SEm). Convergent validity was assessed using Spearman correlation among Skindex-16 scores, serologic titers, and other patient-reported outcome measures. Floor or ceiling domain scores (<20% of sample scoring either lowest or highest possible domain scores, respectively) were assessed for Skindex-16. Structural validity was assessed using confirmatory factor analysis (CFA). Results: The study included 192 patients with 212 visits (median age, 68 years [IQR, 58-76 years]; 123 of 212 women [58.0%]) with Skindex-16 scores (64 in flare state and 148 in nonflare state). Median Skindex-16 domain scores were higher for all disease categories among patients in the flare state compared with those in the nonflare state (pemphigoid [emotions: flare, 52.4 (IQR, 38.1-69.0); nonflare, 7 (IQR, 0-17); symptoms: flare, 37.5 (IQR, 29.2-58.0); nonflare, 13 (IQR, 0-25); functioning: flare, 26.7 (IQR, 10.0-56.7); nonflare, 0 (IQR, 0-3)]; pemphigus [emotions: flare, 54.8 (IQR, 31.0-81.0; nonflare, 0 (IQR, 0-19); symptoms: flare, 58.3 (IQR, 41.7-70.8); nonflare, 4 (IQR, 0-12.5); functioning: flare, 26.7 (IQR, 13.3-83.3); nonflare, 0 (IQR, 0-3.33)]; dermatitis herpetiformis [emotions: flare, 72.6 (IQR, 34.7-90.5); nonflare, 14.3 (IQR, 2.4-26.2); symptoms: flare, 69 (IQR, 31.3-85.4); nonflare, 12.5 (IQR, 0-29.2); functioning: flare, 38.3 (IQR, 5.0-63.2); nonflare, 0 (IQR, 0-13.3)]. This difference exceeded SEm cut points. Cronbach α was greater than 0.80 for all domains and AIBDs. Moderate or low correlations were seen with desmoglein 1 and bullous pemphigoid 180 titers. Moderate correlation existed between Skindex-16 and Patient-Reported Outcomes Measurement Information System Depression scores (emotions: ρ = 0.40; symptoms: ρ = 0.41; functioning: ρ = 0.48), and strong correlation existed between Skindex-16 and patient-reported disease severity (emotions: ρ = 0.71; symptoms: ρ = 0.73; functioning: ρ = 0.66). Floor domain scores greater than 20% were seen among patients in the nonflare state, but ceiling domain scores were rare (<10% for all domains); CFA model fit was poor. Conclusions and Relevance: In this cross-sectional study, SRQL was highly associated with flare of AIBDs. Skin-related quality of life was worse during periods without flare among patients with pemphigoid and dermatitis herpetiformis compared with pemphigus, highlighting residual SRQL morbidity. Skindex-16 showed good construct validity, but the poor CFA model fit needs further research. Clinical measurement of SRQL in AIBDs can add critical disease-severity information.

Diagnostics for Dermatologic Diseases with Autoantibodies.

BACKGROUND: Dermatologic diseases with autoantibodies were recognized early as autoimmunity became accepted as a pathogenic immunologic concept. Laboratory testing to identify disease-defining autoantibodies and investigate their role in pathophysiology has evolved since. CONTENT: Blistering dermatologic diseases, profiled by autoantibody production, target epithelial components critical in cell-cell and cell-matrix adhesion, resulting in epithelial separation and other characteristic features of the disorders. This review covers the clinical indications for dermatologic disease-related autoantibody testing, the specifics of procuring specimens to test, the available diagnostic tests, and information provided by the testing. Atypical, uncharacteristic, and less well-known clinical and autoantibody profiles as well as several of the many future prospects for expansion of the testing applications are elaborated on in the online Data Supplement. SUMMARY: Autoantibody-associated dermatologic diseases are acquired immunologic disorders that have considerable clinical implications affecting essential barrier functions of skin and mucous membranes and causing discomfort, including pain and pruritus. Certain of the diseases can have life-threatening manifestations, and treatments can have significant side-effects. The skin diseases may presage other clinical associations that are important to recognize and treat. Laboratory testing aids in the diagnosis of these diseases through identification of the autoantibodies and is essential for prompt and precise knowledge of the disease type for prognosis, further clinical evaluations, and treatment decisions.

Autoimmunity to desmocollin 3 in pemphigus vulgaris.

Pemphigus vulgaris is a blistering disease associated with autoantibodies to the desmosomal adhesion protein, desmoglein 3. Genetic deficiency of desmoglein 3 in mice mimics autoimmunity to desmoglein 3 in pemphigus vulgaris, with mucosal-dominant blistering in the suprabasal layer of the epidermis. Mice with an epidermal-specific deletion of desmocollin 3, the other major desmosomal cadherin isoform expressed in the basal epidermis, develop suprabasal blisters in skin that are histologically identical to those observed in pemphigus vulgaris, suggesting that desmocollin 3 might be a target of autoantibodies in some pemphigus vulgaris patients. We now demonstrate that desmocollin 3 is an autoantigen in pemphigus vulgaris, illustrated in a patient with mucosal-dominant blistering. Six of 38 pemphigus vulgaris and one of 85 normal serum samples immunoprecipitate desmocollin 3 (P = 0.003). Incubation of patient IgG with human keratinocytes causes loss of intercellular adhesion, and adsorption with recombinant desmocollin 3 specifically prevents this pathogenic effect. Additionally, anti-desmocollin 3 sera cause loss of keratinocyte cell surface desmocollin 3, but not desmoglein 3 by immunofluorescence, indicating distinct cellular pathogenic effects in anti-desmocollin and anti-desmoglein pemphigus, despite their identical clinical presentations. These data demonstrate that desmocollin 3 is a pathogenic autoantigen in pemphigus vulgaris and suggest that pemphigus vulgaris is a histological reaction pattern that may result from autoimmunity to desmoglein 3, desmocollin 3, or both desmosomal cadherins.

Novel screening assay performance in pediatric celiac disease and adult dermatitis herpetiformis.

OBJECTIVES: : Several serologic assays are commercially available to aid in the diagnosis of gluten-sensitive enteropathy (GSE). Our objective in this study was to assess the performance of a novel combined antigen-screening assay for GSE. PATIENTS AND METHODS: : Deidentified sera from 111 pediatric patients suspected of having celiac disease (CD), 130 adults diagnosed with dermatitis herpetiformis (DH), and 77 pediatric and 49 adult normal controls were included in the study. Sera from 10 patients submitted to our laboratory for GSE testing with IgA deficiency and IgG antibodies against 1 or more of the traditional serologic markers associated with GSE were also included. All sera were screened for antibodies (IgA and IgG) against tissue transglutaminase (tTG) and deamidated gliadin peptides (DGP) by enzyme immunoassay (EIA) in a single test well. In addition, all sera were assessed for each individual marker and isotype using separate EIAs. RESULTS: : The IgA/IgG anti-tTG/DGP EIA screen was 92.6% sensitive and 94.3% specific in pediatric CD and detected 1 patient (Marsh 3c) who was IgA anti-tTG negative; this patient was not IgA deficient (<7.0 mg/dL). All 10 IgA-deficient sera gave positive results by the tTG/DGP EIA screen. Sensitivity and specificity of the tTG/DGP EIA screen in retrospective and prospective DH were 65% and 100% versus 62% and 100%, respectively. CONCLUSIONS: : The new IgA/IgG anti-tTG/DGP EIA screen was slightly more sensitive than IgA anti-tTG alone in pediatric CD. This novel screening assay may allow the current recommendation of measuring total serum IgA in suspected GSE patients to be eliminated.

A subset of patients with pemphigoid (herpes) gestationis has serological evidence of celiac disease.

BACKGROUND: Pemphigoid (herpes) gestationis (PG) is an uncommon, self-limited disease with other autoimmune associations; however, celiac disease (CD) is not recognized as one. METHODS: From 71 patients' sera submitted for herpes gestationis factor (HGF) testing over a 5-year period, 12 were consistent with PG demonstrating HGF and increased IgG BP180 antibody levels; these sera were tested for IgA and IgG endomysial antibodies (EMA), epithelial basement membrane zone and cell surface antibodies by indirect immunofluorescence, and for IgA and IgG tissue transglutaminase (transglutaminase 2 or TG2) antibodies, IgA epidermal transglutaminase (transglutaminase 3 or TG3) antibodies, IgG BP230, and IgG desmoglein 1 and desmoglein 3 antibodies by enzyme-linked immunosorbent assays (ELISAs). RESULTS: Three of 12 patients' sera with PG (25%) had CD antibodies with positive IgA EMA and increased IgA TG2 antibody levels; two of these had positive IgG EMA, and one other had an increased IgA TG3 antibody level. CONCLUSIONS: A subset of patients with serological findings of PG also has serological evidence of CD, which may have implications in the etiopathogenesis of PG and which reveals important information about the mother's, and possibly her infant's, health.

A Nonsynonymous Variant in the GOLM1 Gene in Cutaneous Malignant Melanoma.

Background: Statistically significant linkage of melanoma to chromosome 9q21 was previously reported in a Danish pedigree resource and independently confirmed in Utah high-risk pedigrees, indicating strong evidence that this region contains a melanoma predisposition gene. Methods: Whole-exome sequencing of pairs of related melanoma case subjects from two pedigrees with evidence of 9q21 linkage was performed to identify the responsible predisposition gene. Candidate variants were tested for association with melanoma in an independent set of 454 unrelated familial melanoma case subjects and 396 unrelated cancer-free control subjects from Utah, and 1534 melanoma case subjects and 1146 noncancer control subjects from Texas (MD Anderson) via a two-sided Fisher exact test. Results: A rare nonsynonymous variant in Golgi Membrane Protein 1 (GOLM1), rs149739829, shared in two hypothesized predisposition carriers in one linked pedigree was observed. Segregation of this variant in additional affected relatives of the index carriers was confirmed. A statistically significant excess of carriers of the variant was observed among Utah case subjects and control subjects (odds ratio [OR] = 9.81, 95% confidence interval [CI] = 8.35 to 11.26, P < .001) and statistically significantly confirmed in Texas case subjects and control subjects (OR = 2.45, 95% CI = 1.65 to 3.25, P = .02). Conclusion: These findings support GOLM1 as a candidate melanoma predisposition gene.

Correlation of duodenal histology with tissue transglutaminase and endomysial antibody levels in pediatric celiac disease.

BACKGROUND & AIMS: IgA antibodies against tissue transglutaminase (TTGA) and endomysium (EMA) are sensitive and specific markers for celiac disease (CD). Data correlating TTGA and EMA levels with degree of villous atrophy are limited. We compared duodenal histopathology in pediatric CD patients with TTGA and EMA serologies, symptoms, height, and weight. METHODS: We identified 117 pediatric patients retrospectively who had serologic testing for IgA TTGA and IgA EMA and duodenal biopsies graded by modified Marsh criteria as 0-3c. Data were analyzed with Spearman rank correlation and multinomial logistic regression. RESULTS: IgA TTGA (r = .704, P < .001) and IgA EMA (r = 0.740, P < .001) correlated with intestinal villous atrophy in pediatric CD patients by Spearman rank correlation. Similar correlations were found in a subset of 23 patients younger than 3 years of age. Multinomial logistic regression revealed increased probability of Marsh 3a or greater changes with increasing TTGA or EMA levels. Strongly positive antibody levels (TTGA >100 units or EMA titer >1:1280) were highly specific (>98%) for Marsh 3a or greater lesions. Among symptoms, abdominal distention and diarrhea were associated with abnormal histology. CONCLUSIONS: IgA TTGA and EMA levels correlate with duodenal villous atrophy in pediatric CD patients. IgA TTGA >100 or EMA >1:1280 were nearly always associated with CD histopathology. With further validation of this observation, strongly positive titers might be considered sufficient for diagnosis of pediatric patients at risk for CD. Symptoms, height, and weight are not reliable predictors of CD.

A novel case of IgA paraneoplastic pemphigus associated with chronic lymphocytic leukemia.

Paraneoplastic pemphigus is an autoimmune vesiculobullous and erosive mucocutaneous disease associated with an underlying malignancy. Reported malignancies include chronic lymphocytic leukemia, non-Hodgkin's lymphoma, Castleman's disease, sarcomas, and rarely solid tumors. Patients with paraneoplastic pemphigus develop characteristic IgG autoantibodies against several antigens including members of the plakin family, bullous pemphigoid antigen 1, and desmosomal proteins. IgA pemphigus is another recently characterized immunobullous disease that presents as a vesiculopustular eruption with neutrophilic infiltration and epidermal acantholysis. Mucous membrane involvement is rare. We report what is to our knowledge a unique case with features of both IgA pemphigus and paraneoplastic pemphigus associated with chronic lymphocytic leukemia.

Rituximab Treatment for Recalcitrant Dermatitis Herpetiformis.

Importance: Dermatitis herpetiformis (DH) is an autoimmune blistering condition seen in the context of celiac disease. While typically managed by gluten-free diet and dapsone, treatment of DH refractory to standard treatments is not well defined. Observations: A man in his 80s with DH not controlled by gluten-free diet (with poor adherence), dapsone, and conventional immune-suppressing agents responded to treatment with rituximab according to the lymphoma protocol (4 weekly infusions of 375 mg/m2). Thirteen months after treatment, the patient had achieved complete resolution of pruritus and clinical manifestations of the disease, as well as normalization of antibodies against epidermal and tissue transglutaminases. He achieved complete clinical and serological remission and has remained symptom-free up to 18 months following treatment. Conclusions and Relevance: We present here the first case of a patient with DH treated with rituximab who achieved complete clinical and serological remission. We suggest rituximab as a viable treatment option for recalcitrant DH.

Pathophysiology of Autoimmune Bullous Diseases: Nature Versus Nurture.

Pemphigus and pemphigoid are the prototypical immunobullous diseases. Although it has been well established that they are caused by deposition of autoreactive antibodies directed against adherence proteins within the skin, the specific genetic and environmental factors leading to development of these diseases continue to be an area of investigation. Herein, we discuss several of the potential environmental triggers that may induce patients to develop immunobullous diseases including medications, viral infections, UV exposure or other radiation injury and dietary factors. In addition, the potential genetic and immunologic mechanisms contributing to the pathogenesis of pemphigus and pemphigoid will be reviewed. The multifactorial nature of these diseases contributes to their complexity and highlights the importance of a detailed personal and family history when caring for these patients.

Population-based prevalence of CDKN2A mutations in Utah melanoma families.

Cyclin-dependent kinase inhibitor 2A (CDKN2A or p16) is the major melanoma predisposition gene. In order to evaluate the candidacy for genetic testing of CDKN2A mutations among melanoma prone families, it is important to identify characteristics that predict a high likelihood of carrying a CDKN2A mutation. We primarily used a unique Utah genealogical resource to identify independent melanoma prone families whom we tested for mutations in CDKN2A, cyclin-dependent kinase 4, and alternate reading frame. We sampled 60 families which met the inclusion criteria of two or more affected first-degree relatives. We found four different pathogenic CDKN2A mutations in five families, mutations of uncertain significance in two families, and known polymorphisms in three families. One of the mutations of uncertain significance, 5' untranslated region -25C>T, has not been previously described. Among our population-based set of Utah families, the prevalence of CDKN2A mutations was 8.2% (4/49); the overall prevalence when physician-referred pedigrees were also considered was between 8.3% (5/60) and 10% (6/60). Having four or more first- or second-degree relatives with melanoma, or a family member with > or =3 primary melanomas, correlated strongly with carrying a CDKN2A mutation. We observed a significantly elevated rate of pancreatic cancer in one of four families with a deleterious CDKN2A mutation.

Population-based analysis of prognostic factors and survival in familial melanoma.

PURPOSE: Familial melanoma patients are reported to present with thinner melanomas, to be younger at the time of diagnosis, and to have a greater likelihood of developing multiple primary tumors. We sought to determine whether melanomas that occur in a familial setting demonstrate different prognostic and survival statistics relative to sporadic melanoma. PATIENTS AND METHODS: This population-based study used the Utah Cancer Registry and Utah Population Database to objectively evaluate prognostic and survival statistics of the familial melanoma population. From 1973 to 1999, there were 7,785 cases of invasive melanoma identified through the Utah Cancer Registry. These were linked to the Utah Population Database, resulting in 2,659 subjects with family-history information from which a familiality score could be calculated. Cases scored in the top ninth percentile were assigned as high familial risk, and the remaining 91% were considered low familial risk. RESULTS: Multivariate logistic-regression analysis found no association between sex, Breslow depth, Clark level, or survival and the familial status. Age at first diagnosis of invasive melanoma was slightly lower in the high-familial-risk group (57 v 60 years; P = .03). High-familial-risk subjects had more melanomas diagnosed at age 30 or younger (12% v 6%; P < .001). A significant difference in the overall number of individuals with two or more primary malignant melanomas was not detected among the groups (P = .2). CONCLUSION: These data suggest that melanomas occurring in the context of an underlying inherited susceptibility do not have a significantly different biologic behavior.

Usefulness (or lack thereof) of immunophenotyping in atypical cutaneous T-cell infiltrates.

Our purpose was to evaluate the interobserver concordance for the diagnoses of mycosis fungoides (MF), atypical dermatoses (AD), and benign dermatoses (BD) and the impact of T-cell immunophenotyping on the diagnoses MF, AD, and BD. Specimens of MF (n = 57), AD (n = 27), BD and normal skin (n = 54) were reviewed by 2 hematopathologists and 1 dermatopathologist to establish diagnostic interobserver concordance by routine morphologic examination. Immunophenotyping was performed to evaluate expression of CD2, CD3, CD4, CD5, CD7, CD8, CD20, CD30, and MIB-1. The interobserver concordance was fair to moderate compared with the original diagnosis. Partial deletion of CD2 alone was associated significantly with MF. Epidermal deletions of 2 or 3 T-cell antigens or 2 T-cell antigens not including CD7 were associated significantly with MF. An elevated CD4/CD8 ratio correlated with MF. Morphologic features were most diagnostic of MF. Immunophenotyping generally resulted in downgrading of the reaction pattern but was helpful in distinguishing MF from benign dermatoses.

Dermatitis herpetiformis and partial IgA deficiency.

Although the specific IgA autoantibody responsible for the pathogenesis of dermatitis herpetiformis (DH) is unknown, the presence of IgA is considered essential in the pathogenesis of DH. To date, no cases of IgA deficiency have been reported in DH. In contrast, IgA deficiency is found in 2% to 3% of patients with celiac disease, a rate 10 to 15 times higher than the normal population. We report 2 patients with DH who also have partial IgA deficiency. We evaluated the sera of these patients for the presence of IgA autoantibodies to endomysium, tissue transglutaminase, epidermal transglutaminase, and gliadin. Both patients were found to have IgA endomysial and tissue transglutaminase antibodies, and serologic markers for DH. Corresponding IgG autoantibodies were not useful serologic markers of DH in the setting of IgA deficiency, as they often are in celiac disease. We then screened 98 DH sera for total IgA levels and identified 1 additional case with IgA deficiency. In conclusion, DH may develop in patients with partial IgA deficiency, indicating that pathogenically directed IgA antibodies are likely sufficient for cutaneous IgA deposition in this disease.