Association of KIR Genes and MHC Class I Ligands with Atopic Dermatitis.

Atopic dermatitis (AD) is a chronic illness that is associated with immune dysregulation. NK cell function has previously been associated with AD. NK cells directly interact with polymorphic HLA class I ligand variants using killer cell Ig-like receptors (KIRs). The purpose of this study was to identify potential associations between NK cell function and AD by evaluating variation in the presence of KIR genes as well as KIR gene interactions with the appropriate HLA class I KIR-specific ligands. Human DNA from the genetics of AD case-control study was used to genotype HLA class I KIR-specific ligands and the presence of KIR genes. In the full cohort, an increased risk of AD was noted for KIR2DL5 (1.51 [1.13, 2.01]), KIR2DS5 (1.72 [1.26, 2.34]), and KIR2DS1 (1.41 [1.04, 1.91]). Individuals with KIR2DS5 or KIR2DS1 and the HLA-C*C2 epitope were at an increased risk of AD (1.74 [1.21, 2.51] and 1.48 [1.04, 2.12], respectively). The HLA-B*-21T (TT) leader sequence increased the risk of AD across ethnicity. African Americans with KIR2DL2, KIR2DS1, KIR2DL5, and KIR2DS5 are more likely to have AD, and the risk increased for KIR2DS1 and KIR2DS5 in the presence of appropriate HLA-C C2 epitope. The risk of AD also increased for individuals with the HLA-B*-21T leader sequence. Future studies should focus on KIR gene allelic variation as well as consider cell-based measurements of KIR and the associated HLA class I epitopes.

HLA Class I Polymorphisms Influencing Both Peptide Binding and KIR Interactions Are Associated with Remission among Children with Atopic Dermatitis: A Longitudinal Study.

Atopic dermatitis (AD) is a disease of immune dysregulation and skin barrier dysfunction with a relapsing, remitting course and has been associated with several different genetic risk variants. HLA represent a highly variable set of genes that code for cell surface protein molecules involved in the Ag-specific immune response, including the regulation or functioning of T cells, NK cells, and APCs. The purpose of this study was to evaluate associations between HLA class I polymorphisms and the progression of AD over time. We evaluated the associations of AD symptoms and HLA class I polymorphisms based on high-resolution two-field typing in a longitudinal cohort of children with AD (up to 10 y of follow-up). Seven hundred and ninety-two children were evaluated every 6 mo, resulting in 12,752 AD evaluations. Using generalized estimating equations and corrected p values, B*44:02 was found to be associated with AD remission (1.83 [1.35, 2.47]; p = 0.0015). The HLA-B residues at position 116 (d-aspartate) and 80 (T-threonine) were associated with remission (1.42 [1.13, 1.76], p = 0.003; corrected p = 0.028) and (1.45 [1.17, 1.80], p = 0.0008; corrected p = 0.0024), respectively. B80T is a killer-cell Ig-like receptor (KIR) site. Our findings reveal that two axes of immune response (T cell and NK cell) may influence disease progression. Identifying binding pocket changes in addition to other factors (e.g., allergens) that increase the risk or severity of AD can improve our understanding of the immunologic mechanisms associated with AD and may lead to personalized therapies for improving patient care.

Longitudinal atopic dermatitis control and persistence vary with timing of disease onset in children: A cohort study.

BACKGROUND: Wide variation exists in the timing of atopic dermatitis (AD) disease onset among children. Distinct trajectories of early-onset, mid-onset, and late-onset AD have been previously described. OBJECTIVE: To evaluate longitudinal disease control and persistence with respect to age at onset of AD. METHODS: A cohort study was performed using the Pediatric Eczema Elective Registry, a prospective observational cohort of subjects with childhood-onset AD. AD control and persistence were assessed biannually for up to 10 years. RESULTS: A total of 8015 subjects with 41,934 person-years of follow-up were included. In longitudinal analyses using generalized linear latent and mixed modeling, older age at onset of AD was associated with better disease control and less-persistent AD. For each additional year of age at onset of AD, the adjusted odds ratios for poorer AD control and for persistent AD were 0.93 (95% confidence interval, 0.91-0.94) and 0.84 (95% confidence interval, 0.80-0.88), respectively. Differences in AD control and persistence among subjects with early-, mid-, and late-onset AD were most pronounced from early adolescence onward. LIMITATIONS: Misclassification bias may arise from using self-reported data on age at onset. Attrition and missing data in longitudinal studies may introduce bias. CONCLUSION: Early-, mid-, and late-onset pediatric AD appear to be clinically distinct subtypes of the disease.

Variations in risk of asthma and seasonal allergies between early- and late-onset pediatric atopic dermatitis: A cohort study.

BACKGROUND: Atopic dermatitis is associated with other allergic conditions, but variations in this "atopic march" are poorly understood. OBJECTIVE: To determine the impact of the age of atopic dermatitis onset on the risk for asthma and seasonal allergies. METHODS: A cohort study was performed using the Pediatric Eczema Elective Registry, which is an observational cohort of subjects with pediatric onset atopic dermatitis. RESULTS: In total, 3966 children were included, and 73% reported atopic dermatitis onset before age 2 years. At baseline, subjects with atopic dermatitis onset at ages 3 to 7 or 8 to 17 years had significantly lower rates of seasonal allergies and asthma than those with onset before age 2. During follow-up, the adjusted relative risks for incident seasonal allergies were 0.82 (95% confidence interval, 0.72-0.91) and 0.64 (95% CI confidence interval, 0.47-0.83) in the 3- to 7- and 8- to 17-years-old at onset groups compared with the age 2 years or younger at onset group. The adjusted risk for incident asthma was not significantly different between the older onset groups and the earliest onset group. LIMITATIONS: Misclassification bias may arise from using self-reported onset age data. CONCLUSIONS: The timing of atopic dermatitis onset may explain part of the variation in the atopic march. These findings may improve future risk stratification of patients for treatment.

KIR Allelic Variation and the Remission of Atopic Dermatitis Over Time.

Atopic dermatitis (AD) is a common chronic skin disease. Although generally thought to be a disease of T-cell dysregulation, recent studies have suggested that immune dysregulation of NK cells is also important. Killer cell Ig-like receptors (KIRs) are involved with NK cell regulation. The Pediatric Eczema Elective Registry is a U.S. nationwide longitudinal cohort with up to 10 y of follow-up in which 655 children had DNA available for full allelic KIR sequencing. Every 6 mo, AD activity was reported by Pediatric Eczema Elective Registry children. Using generalized estimating equations, we evaluated the association of KIR allelic variation in concert with known HLA binding ligands and whether the child reported AD in "remission" (no skin lesions and not using AD medication). KIR2DS4*001:01 (odds ratio 0.53, 95% CI [0.32, 0.88]) and KIR2DL4*001:02 (0.54, [0.33, 0.89]) in the presence of C*04:01 had the largest effect on decreasing the likelihood of AD remission. The haplotype KIR 2DL4*001:02 ∼ 2DS4*001:01 ∼ 3DL2*002:01 (0.77, [0.60, 0.99]) was also associated with a decreased likelihood of AD remission. Our findings add to the general body of evidence of a growing literature on the importance of NK cells with respect to the immunopathogenesis and natural history of AD.

Association between atopic dermatitis, autoimmune illnesses, Epstein-Barr virus, and cytomegalovirus.

Atopic dermatitis (AD) is a Th2-driven inflammatory skin disease that has been associated with other autoimmune illnesses (AI) and has a well-known predisposition to infection with herpes simplex virus infection. Yet, few studies have evaluated the association between atopic dermatitis, autoimmune illness, and other human herpes virus (HHV) infections such as cytomegalovirus (CMV) and Epstein-Barr virus (EBV). We aimed to evaluate the association between AD, specific AIs, CMV, and EBV in a random sample of the Optum Clinformatics Data Mart database, a US administrative claims database. AD was defined based on ICD diagnostic codes. Patients with AD were exact matched to those without AD on sex, age at enrollment, time observed in the dataset and census division. Our outcomes of interest were rheumatoid arthritis (RA), Crohn's disease (CD), ulcerative colitis (UC), multiple sclerosis (MS), CMV, and EBV infection as defined by specific ICD codes. Logistic regression models were used to examine the association between AD and our outcomes of interest [odds ratio (95% confidence intervals)]. Our full cohort included 40,141,017 patients. In total, 601,783 patients with AD were included. As expected, patients with AD had a higher prevalence of asthma and seasonal allergies versus controls. Individuals with AD have an increased risk of EBV, CMV, RA, CD, UC, and MS. While we cannot demonstrate a causal association, the observed associations between AD and AI may be in part mediated by these types of HHV (i.e., CMV and EBV), a finding that merits further study.

Association of KIR2DL5, KIR2DS5, and KIR2DS1 allelic variation and atopic dermatitis.

Natural killer cells (NK) have been associated with the pathophysiology of atopic dermatitis (AD). NK function is regulated by killer cell Ig-like receptor family (KIR) receptors that interact with HLA ligands. The study goal was to focus on allelic variation in genes KIR2DL5, KIR2DS5, and KIR2DS1 with respect to AD. This was a case-control study of individuals with (n = 313) and without (n = 176) AD. Associations were estimated using logistic regression. The prevalence of KIR2DL5 was 52.5% (95% CI 48.0,57.0), KIR2DS5 was 33.0% (28.8,37.3), and KIR2DS1 was 33.6% (29.4,38.0). The presence of the KIR2DL5*001:01 increased the odds of having AD by about 86% (odds ratio (OR): 1.86(1.23,2.82) p = 0.003). The risk for individuals homozygous for KIR2DL5*001:01 was even greater (OR: 2.16 (95% CI 1.31,3.53) p = 0.0023). The odds of having AD with KIR2DL5*001:01 was similar in Whites and Blacks. Allelic variation in KIR2DS5 and KIR2DS1 was not associated with AD. There is no known HLA binding ligand for KIR2DL5. The effect of KIR2DL5*001:01 increased in the presence of HLA-B*-21TT leader sequence (2.46(1.37,4.41) p = 0.0025) and the HLA-C2 ligand (2.07 (1.37,4.41, p = 0.000002). Our study shows an independent association of the KIR2DL5*001:01 with AD and is the first study to associate AD with KIR allelic variation.

A combination of HLA-DP α and ß chain polymorphisms paired with a SNP in the DPB1 3' UTR region, denoting expression levels, are associated with atopic dermatitis.

Introduction: Components of the immune response have previously been associated with the pathophysiology of atopic dermatitis (AD), specifically the Human Leukocyte Antigen (HLA) Class II region via genome-wide association studies, however the exact elements have not been identified. Methods: This study examines the genetic variation of HLA Class II genes using next generation sequencing (NGS) and evaluates the resultant amino acids, with particular attention on binding site residues, for associations with AD. The Genetics of AD cohort was used to evaluate HLA Class II allelic variation on 464 subjects with AD and 384 controls. Results: Statistically significant associations with HLA-DP α and ß alleles and specific amino acids were found, some conferring susceptibility to AD and others with a protective effect. Evaluation of polymorphic residues in DP binding pockets revealed the critical role of P1 and P6 (P1: α31M + (ß84G or ß84V) [protection]; α31Q + ß84D [susceptibility] and P6: α11A + ß11G [protection]) and were replicated with a national cohort of children consisting of 424 AD subjects. Independently, AD susceptibility-associated residues were associated with the G polymorphism of SNP rs9277534 in the 3' UTR of the HLA-DPB1 gene, denoting higher expression of these HLA-DP alleles, while protection-associated residues were associated with the A polymorphism, denoting lower expression. Discussion: These findings lay the foundation for evaluating non-self-antigens suspected to be associated with AD as they potentially interact with particular HLA Class II subcomponents, forming a complex involved in the pathophysiology of AD. It is possible that a combination of structural HLA-DP components and levels of expression of these components contribute to AD pathophysiology.

Association of Atopic Dermatitis Severity With Learning Disability in Children.

IMPORTANCE: Recent population-based data indicate that atopic dermatitis (AD) is associated with learning disability (LD) in children, but the association between AD severity and LD is unknown. OBJECTIVE: To evaluate the association of AD severity with learning problems in children with AD. DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study analyzed data of US participants enrolled in the Pediatric Eczema Elective Registry (PEER) between November 1, 2004, and November 30, 2019. Participants were children aged 2 to 17 years at registry enrollment with physician-confirmed diagnosis of AD and had completed 10 years of follow-up in PEER. EXPOSURES: Atopic dermatitis severity measured by both the Patient-Oriented Eczema Measure (POEM) score and self-report. The POEM scores ranged from 0 to 28, with strata of clear or almost clear skin (0-2), mild (3-7), moderate (8-16), severe (17-24), and very severe (25-28). Self-reported AD severity was categorized as clear skin or no symptoms, mild, moderate, or severe. MAIN OUTCOMES AND MEASURES: Learning disability diagnosed by a health care practitioner, as reported by the participants or their caregivers. RESULTS: Among the 2074 participants with AD (1116 girls [53.8%]; median [interquartile range (IQR)] age, 16.1 [13.9-19.5] years at 10-year follow-up), 169 (8.2%) reported a diagnosis of an LD. Children with an LD vs those without an LD were more likely to have worse AD severity, as measured by the median (IQR) total POEM score (5 [1-10] vs 2 [0-6]; P < .001), POEM severity category (moderate AD: 50 of 168 [29.8%] vs 321 of 1891 [17.0%]; severe to very severe AD: 15 of 168 [8.9%] vs 85 of 1891 [4.5%]; P < .001); and self-report (moderate AD: 49 of 168 [29.2%] vs 391 of 1891 [20.7%]; severe AD: 11 of 168 [6.5%] vs 64 of 1891 [3.4%]; P < .001). In multivariable logistic regression models adjusted for sex, age, race/ethnicity, annual household income, age of AD onset, family history of AD, and comorbid conditions, participants with mild AD (odds ratio [OR], 1.72; 95% CI, 1.11-2.67), moderate AD (OR, 2.09; 95% CI, 1.32-3.30), and severe to very severe AD (OR, 3.10; 95% CI, 1.55-6.19) on the POEM were all significantly more likely to have reported an LD than those with clear or almost clear skin. CONCLUSIONS AND RELEVANCE: This cross-sectional study found that worse AD severity was associated with greater odds of reported LD, independent of socioeconomic characteristics, AD onset age, and other related disorders. Although additional prospective and mechanistic studies are needed to clarify the association of AD with learning, the findings suggest that children with more severe AD should be screened for learning difficulties to initiate appropriate interventions that can mitigate the consequences of an LD.

Evaluation of the use of prognostic information for the care of individuals with venous leg ulcers or diabetic neuropathic foot ulcers.

This is a randomized factorial design clinical trial that investigates the efficacy and feasibility of providing prognostic information on wound healing. Prognostic information was provided based on baseline or 4-week wound characteristics. Healing rates were then determined at 24 weeks for venous leg ulcers and 20 weeks for diabetic neuropathic foot ulcers. Centers that had access to baseline information for venous leg ulcer prognosis had an odds ratio (OR) of healing of 1.42 (95% confidence interval [CI]: 1.03, 1.95) while centers that had access to information at 4 weeks had an OR of healing of 1.43 (95% CI: 1.05, 1.95) compared with controls. Diabetic neuropathic foot ulcer patients treated in centers that had been randomized to receive only 4-week prognostic information were more likely to heal than individuals seen in centers randomized to receive no intervention (OR 1.50, 95% CI: 1.05, 2.14). Our study found that it is feasible and efficacious to provide prognostic information on venous leg ulcers and diabetic neuropathic foot ulcers in a wound care setting using an existing administrative database. This intervention was easy to administer and likely had low associated costs. This method of dispersing prognostic information to healthcare providers should be expanded to include recently published treatment algorithms.

Racial/Ethnic Variation in Use of Ambulatory and Emergency Care for Atopic Dermatitis among US Children.

Previous studies indicate racial/ethnic differences in health care utilization for pediatric atopic dermatitis (AD), but do not account for disease severity impact. We sought to examine the relationship between race/ethnicity and health care utilization, both overall and by specific visit type, while accounting for AD control. A longitudinal cohort study of children with AD in the United States was performed to evaluate the association between race/ethnicity and health care utilization for AD. AD control and health care utilization were assessed biannually. Our study included 7,522 children (34.2% white, 54.2% black, and 11.5% Hispanic) who were followed for a median of 4 years (interquartile range 0.9-8.4 years). After adjusting for sociodemographic and other factors, black and Hispanic children were up to nearly threefold more likely than white children to receive medical care for AD across almost all levels of AD control. Black and Hispanic children had higher odds of primary care and emergency visits compared to whites. Black children with poorly controlled AD were significantly less likely to see a dermatologist than white children with similarly poorly controlled AD (odds ratio = 0.74, 95% confidence interval = 0.64-0.85 for limited control; odds ratio = 0.59, 95% confidence interval = 0.47-0.76 for uncontrolled AD). Together, these findings suggest the presence of racial/ethnic disparities in health care utilization for AD.

Validity of subject self-report for acne.

BACKGROUND/OBJECTIVE: Acne prevalence studies often use subject self-report as data source. Our aim was to evaluate the validity of acne self-report. METHODS: Responses of university students to an acne questionnaire were compared to the trained observer's concurrent examination of acne. The validity of self-report was measured by sensitivity, specificity, positive predictive value and negative predictive value. Agreement was measured by Cohen's kappa and correct classification percentage. RESULTS: The sensitivity of self-report was 0.55 (95% CI 0.47-0.63), the specificity was 0.72 (95% CI 0.63-0.80), the positive predictive value was 0.70 (95% CI 0.61-0.78), and the negative predictive value was 0.57 (95% CI 0.49-0.65). Cohen's kappa was 0.26 (95% CI 0.15-0.38) and correct classification percentage was 63. CONCLUSIONS: Validity of self-report was moderate at best and agreement was fair, indicating that college students could not accurately report that they have acne. This is likely not sufficient for clinical or research activities or to assure that individuals who self-guide their acne therapy actually have acne.

Association Between Malignancy and Topical Use of Pimecrolimus.

IMPORTANCE: A black box warning describes a potential risk of malignancy associated with topical use of pimecrolimus to treat atopic dermatitis due to its similarity to oral calcineurin inhibitors used in solid-organ transplantation and spontaneous reporting of malignancies, including lymphomas and cutaneous malignancies. OBJECTIVE: To evaluate the risk of malignancy in a postmarketing study of children exposed to pimecrolimus. DESIGN, SETTING, AND PARTICIPANTS: A longitudinal cohort study among a nationwide ongoing long-term cohort of children enrolled in the Pediatric Eczema Elective Registry (PEER) who had a history of atopic dermatitis and pimecrolimus use with data available up through May 2014. MAIN OUTCOMES AND MEASURES: Reports of malignancy among those in the PEER compared with expected rates from the Surveillance, Epidemiology, and End Results (SEER) program. RESULTS: Overall, 7457 children were enrolled in the PEER, for a total of 26,792 person-years. Children used a mean (SD) of 793 (1356) g of pimecrolimus when enrolled in the study. As of May 2014, five malignancies had been reported. These include 2 leukemias, 1 osteosarcoma, and 2 lymphomas. No skin cancers were reported. The standardized incidence ratio for all malignancies (primary outcome) based on the age-standardized SEER population was 1.2 (95% CI, 0.5-2.8). As secondary analyses, the standardized incidence ratios (based on 2 cases for each) were 2.9 (95% CI, 0.7-11.7) for lymphoma and 2.0 (95% CI, 0.5-8.2) for leukemia. None of these findings were statistically significant. CONCLUSIONS AND RELEVANCE: Based on more than 25,000 person-years of follow-up, it seems unlikely that topical pimecrolimus as it was used in the PEER cohort to treat atopic dermatitis is associated with an increased risk of malignancy.

Association of HLA-DRB1 genetic variants with the persistence of atopic dermatitis.

Atopic dermatitis (AD) is a waxing and waning illness of childhood that is likely caused by interactions between an altered skin barrier and immune dysregulation. The goal of our study was to evaluate the association of DRB1 genetic variants and the persistence of AD using whole exome sequencing and high resolution typing. DRB1 was interrogated based on previous reports that utilized high throughput techniques. We evaluated an ongoing nation-wide long-term cohort of children with AD in which patients are asked every 6months about their medication use and their AD symptoms. In total, 87 African-American and 50 European-American children were evaluated. Genetic association analysis was performed using a software tool focusing on amino acid variable positions shared by HLA-DRB1 alleles covering the antigen presenting domain. Amino acid variations at position 9 (pocket 9), position 26, and position 78 (pocket 4) were marginally associated with the prevalence of AD. However, the odds ratio was 0.30 (0.14, 0.68; p=0.003) for residue 78, 0.27 (0.10, 0.69; p=0.006) for residue 26 and not significant for residue 9 with respect to the persistence of AD. In conclusion, amino acid variations at peptide-binding pockets of HLA-DRB1 were associated with the persistence of AD in African-American children.

Mail surveys can achieve high response rates in a dermatology patient population.

In order to understand the burden of skin disease on patient populations, researchers need to be able to measure exposures and outcomes of interest in a population-based study. One method of obtaining such information is mailed patient surveys. This method of obtaining information, however, raises concerns regarding possible low response rates, and to the best of our knowledge, this method has not been attempted in large dermatology patient populations with a high response rate. We sought to determine whether using a slightly modified version of the Dillman Total Design Method as a mailed survey protocol would result in a high response rate in a dermatology population. A mail survey was sent using a slightly modified version of Dillman's Total Design Method to 4894 patients seen in the Dermatology Department of the University of Pennsylvania, who were diagnosed with nonmelanoma skin cancer, dermatophytosis, acne rosacea, seborrheic keratosis, or warts; 74.1% of the subjects responded to the mailings; 69.8% (n=3203) of patients returned a completed survey. Response rates (both as overall response and as survey completers only) were high across a wide spectrum of dermatologic illnesses and did not vary significantly by entry diagnosis. Dillman's Total Design Method appears to be an effective tool for researchers studying the burden of skin disease in a large sample of dermatology patients.

Validity of patient self-reported history of skin cancer.

OBJECTIVE: To determine the validity of patient self-report of skin cancer history. DESIGN: A cohort of patients was randomly selected from the case group in a prior case-control study involving skin cancer, and a second cohort was randomly selected from the controls of that study. Patient self-reported history (as determined by responses to a survey) was compared with the gold standard of chart documentation of a pathology report or a procedure note from Mohs micrographic surgery demonstrating skin cancer. SETTING: University-based outpatient dermatology clinic. PATIENTS: Three hundred patients were selected. MAIN OUTCOME MEASURES: Patients were considered to have correctly classified their skin cancer history if their self-reported history was consistent with chart documentation. RESULTS: We obtained chart information for 258 patients.Of those patients, 183 (70.9%) had chart documentation of nonmelanoma skin cancer, and 16 (6.2%) had chart documentation of a melanoma. Using chart documentation as the gold standard, we found that patients correctly identified their basal cell carcinoma status in 84.3% of cases; their squamous cell carcinoma status in 81.5% of cases; their overall nonmelanoma skin cancer status in 91.8% of cases; their melanoma status in 94.8% of cases; and their overall skin cancer status in 92.6% of cases. Patients' self-reported history of skin cancer of any type had a positive predictive value of 95.1% and a negative predictive value of 85.9%. CONCLUSIONS: Self-reported history of skin cancer had a high degree of sensitivity and specificity and a high positive and negative predictive value within the study population. Obtaining medical information by patient report appears to be a useful tool for determining medical history of skin cancer.