COVID-19 Vaccination in Patients with Inborn Errors of Immunity Reduces Hospitalization and Critical Care Needs Related to COVID-19: a USIDNET Report

BACKGROUND

The CDC and ACIP recommend COVID-19 vaccination for patients with inborn errors of immunity (IEI). Not much is known about vaccine safety in IEI, and whether vaccination attenuates infection severity in IEI.

OBJECTIVE

To estimate COVID-19 vaccination safety and examine effect on outcomes in patients with IEI.

METHODS

We built a secure registry database in conjunction with the US Immunodeficiency Network to examine vaccination frequency and indicators of safety and effectiveness in IEI patients. The registry opened on January 1, 2022, and closed on August 19, 2022.

RESULTS

Physicians entered data on 1245 patients from 24 countries. The most common diagnoses were antibody deficiencies (63.7%). At least one COVID-19 vaccine was administered to 806 patients (64.7%), and 216 patients received vaccination prior to the development of COVID-19. The most common vaccines administered were mRNA-based (84.0%). Seventeen patients were reported to seek outpatient clinic or emergency room care for a vaccine-related complication, and one patient was hospitalized for symptomatic anemia. Eight hundred twenty-three patients (66.1%) experienced COVID-19 infection. Of these, 156 patients required hospitalization (19.0%), 47 required ICU care (5.7%), and 28 died (3.4%). Rates of hospitalization (9.3% versus 24.4%, p < 0.001), ICU admission (2.8% versus 7.6%, p = 0.013), and death (2.3% versus 4.3%, p = 0.202) in patients who had COVID-19 were lower in patients who received vaccination prior to infection. In adjusted logistic regression analysis, not having at least one COVID-19 vaccine significantly increased the odds of hospitalization and ICU admission.

CONCLUSION

Vaccination for COVID-19 in the IEI population appears safe and attenuates COVID-19 severity.

Lower NK cell numbers in children with untreated juvenile dermatomyositis during the COVID-19 pandemic

RNA viruses have been posited as triggers for Juvenile Dermatomyositis (JDM). The COVID-19 pandemic proved a unique opportunity to observe the effect of a novel RNA virus on JDM incidence and phenotype. We found the incidence of JDM increased from average of 6.9 cases per year from 2012 to 2019 to 9 cases per year from 2020 to 2021. We compared markers of disease activity in the patients diagnosed with JDM prior to and during the pandemic and found that patients diagnosed with JDM during the pandemic had significantly lower average NK cell counts 90.75(± 76) vs 163(±120) (P = 0.038) and NK cell percentage 3.63% (±2.3) vs. 6.6% (±4.1), (P = 0.008). Other markers of JDM did not significantly change. This study suggests that COVID-19 may be a viral trigger for JDM in selected cases and that NK cell dysregulation may be of particular interest in future research of virally triggered JDM.

Juvenile dermatomyositis: association between nail fold capillary end row loop- area under the curve- and disease damage indicators

BACKGROUND

Juvenile Dermatomyositis (JDM) is a rare autoimmune disease characterized by skin and muscle inflammation. The loss of nail fold capillary end row loops (ERL) is evidence of small vessel involvement in JDM. This study aimed to examine the specific association of ERL over the disease course with evidence of JDM disease damage.

METHODS

We analyzed data from 68 initially treatment-naïve JDM children who had been observed for at least five years with multiple ERL density assessments. The JDM disease course were categorized into monocyclic short, monocyclic long, polycyclic, and chronic. The ERL capillary count was cumulatively evaluated using the area under the curve (AUC) method.

RESULTS

The mean ERL density for the treatment-naive JDM was significantly lower than that of their healthy age-matched controls (4.8 ± 1.6 /mm vs. 7.9 ± 0.9 /mm; p < 0.0001). The ERL AUC was significantly lower in children with a chronic disease course compared to those with a monocyclic short (p = 0.001) or monocyclic long disease course (p = 0.013). JDM patients with lipodystrophy had lower ERL AUC than those without lipodystrophy (p = 0.04). There was no association between ERL AUC and calcifications or fractures.

CONCLUSION

Persistently decreased ERL capillary density, reflected by low ERL AUC, is associated with a chronic disease course and lipodystrophy in JDM. Despite medical therapy, the mean ERL count remained below normal even after five years, particularly in polycyclic and chronic cases. It is not clear that restoring normal capillary density is currently feasible in children with JDM.

Nailfold capillary density in 140 untreated children with juvenile dermatomyositis: an indicator of disease activity

BACKGROUND

We lack a reliable indicator of disease activity in Juvenile Dermatomyositis (JDM), a rare disease. The goal of this study is to identify the association of nailfold capillary End Row Loop (ERL) loss with disease damage in children with newly diagnosed, untreated JDM.

FINDINGS

We enrolled 140 untreated JDM and 46 age, race and sex matched healthy controls, ages 2-17. We selected items from the Juvenile Myositis Registry for analysis. Variables include average ERL density of 8 fingers, average capillary pattern, hemorrhages, and clinical and laboratory correlates. Laboratory data includes Myositis Specific Antibodies (MSA), disease activity scores (DAS), Childhood Myositis Assessment Scale (CMAS), and standard clinical serologic data. The reduced mean ERL density is 5.1 ± 1.5/mm for untreated JDM vs 7.9 ± 0.9/mm for healthy controls, p < 0.0001, and is associated with DAS-skin, r = -0.27 p = 0.014, which did not change within the age range tested. Untreated JDM with MSA Tif-1-γ had the lowest ERL density, (p = 0.037); their ERL patterns were primarily "open" and the presence of hemorrhages in the nailfold matrix was associated with dysphagia (p = 0.004).

CONCLUSIONS

Decreased JDM ERL density is associated with increased clinical symptoms; nailfold hemorrhages are associated with dysphagia. Duration of untreated disease symptoms and MSA, modify NFC shape. We speculate nailfold characteristics are useful indicators of disease activity in children with JDM before start of therapy.

Food Allergy: Knowledge and Attitude of Primary School Teachers in Makkah Region, Saudi Arabia

Food allergy is a serious and potentially life-threatening medical condition that affects both adults and children. School teachers are considered to be among the first line of defense in identifying and responding to such situations, as 22% of food allergic reactions occur in schools. It is, therefore, important to understand the knowledge and attitudes of school teachers toward food allergy. This study is a descriptive, cross-sectional investigation conducted using an online questionnaire from December 2022 to February 2023. We collected data from 413 primary school teachers in Makkah region, Saudi Arabia. SPSS version 21 (IBM Corp., Armonk, NY) was used to analyze the data. Out of 413 teachers who met the inclusion criteria, only 14.5% demonstrated good awareness levels (scoring above 60% on the knowledge questionnaire) regarding food allergy, with young teachers making up the highest proportion as 26.1% of younger teachers had good awareness levels compared to 8.8% of teachers aged 51-60 years (p = 0.012). Additionally, 46.7% of the teachers knew the symptoms of a severe allergic reaction, and only 16.7% knew that they should use an epinephrine pen as the first step in managing a severe allergic reaction. School teachers have insufficient knowledge about food allergies, underscoring the importance of establishing school policies to handle food allergies. Such policies should encompass the adoption of a comprehensive food allergy action plan, training programs for school personnel, and educational campaigns.

Juvenile Dermatomyositis: Association between Nail Fold Capillary End Row Loops Area Under the Curve and Disease Damage Indicators

Background

Juvenile Dermatomyositis (JDM) is a rare autoimmune disease characterized by skin and muscle inflammation. The loss of nail fold capillary end row loops (ERL) is evidence of small vessel involvement in JDM. This study aimed to examine the association of ERL over the disease course and evidence of disease damage.

Methods

We analyzed data from 68 initially treatment-naïve JDM children who had been observed for at least five years with multiple ERL density assessments. The JDM disease courses were categorized into monocyclic short, monocyclic long, polycyclic, and chronic. The ERL capillary count was cumulatively evaluated using the area under the curve (AUC) method.

Results

The mean ERL density for the treatment-naive JDM was significantly lower than that of their healthy controls (4.8±1.6 /mm vs. 7.9±0.9 /mm; p <0.0001). The ERL AUC was significantly lower in children with chronic disease course compared to those with monocyclic short (p =0.001) or monocyclic long disease course (p =0.013). JDM patients with lipodystrophy had lower ERL AUC than those without lipodystrophy (p =0.04). There was no association between ERL AUC and calcifications or fractures.

Conclusion

Persistently decreased ERL capillary density, evident by low ERL AUC, is associated with chronic disease course and lipodystrophy in JDM. Despite medical therapy, the mean ERL count remained below normal even after five years, particularly in polycyclic and chronic cases. Therefore, the goal of restoring normal capillary density in children with JDM might be challenging and require novel therapeutic strategies targeting their underlying endothelial dysfunction.

B Cell Lymphocytosis in Juvenile Dermatomyositis

In this study, we determined if B lymphocytosis may serve as a JDM biomarker for disease activity. Children with untreated JDM were divided into two groups based on age-adjusted B cell percentage (determined through flow cytometry): 90 JDM in the normal B cell group and 45 in the high B cell group. We compared through T-testing the age, sex, ethnicity, duration of untreated disease (DUD), disease activity scores for skin (sDAS), muscle (mDAS), total (tDAS), CMAS, and neopterin between these two groups. The patients in the high B cell group had a higher tDAS (p = 0.009), mDAS (p = 0.021), and neopterin (p = 0.0365). Secondary analyses included B cell values over time and BAFF levels in matched patients with JM (juvenile myositis) and concurrent interstitial lung disease (ILD); JM alone and healthy controls Patient B cell percentage and number was significantly higher after 3-6 months of therapy and then significantly lower on completion of therapy (p =< 0.0001). The JM groups had higher BAFF levels than controls 1304 vs. 692 ng/mL (p = 0.0124). This study supports B cell lymphocytosis as a JDM disease-activity biomarker and bolsters the basis for B cell-directed therapies in JDM.

Advanced computational analysis of CD40LG variants in atypical X-linked hyper-IgM syndrome

X-Linked Hyper-IgM Syndrome is caused by pathogenic variants in CD40LG. Three patients with atypical clinical and immunological features were identified with variants in CD40LG requiring further characterization. Flow cytometry was used to evaluate CD40L protein expression and binding capacity to a surrogate receptor, CD40-muIg. Though functional anomalies were observed, there was still a lack of clarity regarding the underlying mechanism. We developed structural models for wild-type and the three variants of CD40L protein observed in these patients (p. Lys143Asn, Leu225Ser and Met36Arg) to evaluate structural alterations by molecular mechanic calculations, and assess protein movement by molecular dynamic simulations. These studies demonstrate that functional analysis of variants of unknown significance in CD40LG can be supplemented by advanced computational analysis in atypical clinical contexts. These studies in combination identify the deleterious effects of these variants and potential mechanisms for protein dysfunction.

Increased Otoferlin Expression in B Cells Is Associated with Muscle Weakness in Untreated Juvenile Dermatomyositis: A Pilot Study

Otoferlin mRNA expression is increased in JDM patients' PBMCs and muscle compared to healthy controls. This study aims to evaluate the role of otoferlin in JDM disease pathophysiology and its association with disease activity in untreated children with JDM. A total of 26 untreated JDM (88.5% female, 92.3% white, non-Hispanic) and 15 healthy controls were included in this study. Otoferlin mRNA expression was determined by qRT-PCR before and a few months after therapy. Detailed flow cytometry of various cell surface markers and cytoplasmic otoferlin was performed to identify cells expressing otoferlin. In addition, muscle otoferlin expression was evaluated in situ in six untreated JDM patients and three healthy controls. There was a significant increase in otoferlin expression in JDM children compared to controls (Median 67.5 vs. 2.1; p = 0.001). There was a positive correlation between mRNA otoferlin expression and the following disease activity markers: disease activity scores (DAS)-total (rs = 0.62, p < 0.001); childhood myositis assessment scale (CMAS) (rs = -0.61, p = 0.002); neopterin (rs = 0.57, p = 0.004) and von Willebrand factor antigen (vWF: Ag) (rs = 0.60, p = 0.004). Most of the otoferlin-positive cells were unswitched B cells (63-99.4%), with 65-75% of them expressing plasmablast markers (CD19+, IgM+, CD38hi, CD24-). The findings of this pilot study suggest that otoferlin expression is associated with muscle weakness, making it a possible biomarker of disease activity. Additionally, B cells and plasmablasts were the primary cells expressing otoferlin.

The von Willebrand Factor Antigen Reflects the Juvenile Dermatomyositis Disease Activity Score

OBJECTIVE

This study determined if an accessible, serologic indicator of vascular disease activity, the von Willebrand factor antigen (vWF:Ag), was useful to assess disease activity in children with juvenile dermatomyositis (JDM), a rare disease, but the most common of the pediatric inflammatory myopathies.

METHODS

A total of 305 children, median age 10 years, 72.5% female, 76.5% white, with definite/probable JDM at diagnosis, were enrolled in the Ann & Robert H. Lurie Cure JM Juvenile Myositis Repository, a longitudinal database. Disease Activity Score (DAS) and vWF:Ag data were obtained at each visit. These data were analyzed using generalized estimating equation (GEE) models (both linear and logistic) to determine if vWF:Ag reflects disease severity in children with JDM. A secondary analysis was performed for untreated active JDM to exclude the effect of medications on vWF:Ag.

RESULT

The vWF:Ag test was elevated in 25% of untreated JDM. We found that patients with elevated vWF:Ag had a 2.55-fold higher DAS total (CI₉₅: 1.83-3.27, p < 0.001). Patients with difficulty swallowing had 2.57 higher odds of elevated vWF:Ag (CI_95: 1.5-4.38, p < 0.001); those with more generalized skin involvement had 2.58-fold higher odds of elevated vWF:Ag (CI₉₅: 1.27-5.23, p = 0.006); and those with eyelid peripheral blood vessel dilation had 1.32-fold higher odds of elevated vWF:Ag (CI₉₅: 1.01-1.72, p = 0.036). Untreated JDM with elevated vWF:Ag had more muscle weakness and higher muscle enzymes, neopterin and erythrocyte sedimentation rate compared to JDM patients with a normal vWF:Ag.

CONCLUSION

vWF:Ag elevation is a widely accessible concomitant of active disease in 25% of JDM.

Hypogammaglobulinaemia and B cell lymphopaenia in Barth syndrome

Barth syndrome (BTHS) is an X linked recessive disorder caused by a mutation in the tafazzin (TAZ) gene classically associated with the triad of neutropaenia and cardiac and skeletal myopathies. Here we present a case of BTHS in a 2-month-old male patient found to have a novel variant of the TAZ gene (hemizygous c.639G>A) leading to early termination of the tafazzin protein (p.Trp213Ter) with presumed loss of function. Our patient was found to have dilated cardiomyopathy, cyclic neutropaenia and growth delays, which in combination with genetic work-up confirmed the diagnosis of BTHS. He also experienced repeated bacterial and viral infections, prompting an immunological work-up which revealed persistent B cell lymphopaenia and hypogammaglobulinaemia. He ultimately required subcutaneous immunoglobulin replacement and GM-CSF for ongoing hypogammaglobulinaemia and neutropaenia. To our knowledge, this case is the first report of BTHS associated with B cell lymphopaenia and hypogammaglobulinaemia.

Improvement of SLC29A3 spectrum disorder-related sensorineural hearing loss after initiation of IL-6 inhibitor

Tocilizumab is reported to reduce systemic inflammation in individuals with SLC29A3 spectrum disorder, but its effect on hearing loss has not been described. The authors present a boy toddler with a history of prematurity, dysphagia, hypersplenism, hyperpigmentation, short height and hearing loss who was referred to the immunology clinic. He initially presented shortly after birth with abnormal hearing screens followed by positive urine test for cytomegalovirus. However, the infection was determined to be postnatally acquired and hearing loss most likely from genetic causes given a family history of hearing loss and consanguinity. A pathogenic variant in SLC29A3 was found on whole-exome sequencing and given concern for SLC29A3 spectrum disorder, steroids were started. Following concerns for development of side effects with chronic steroid use, he was switched to interleukin 6 inhibitor therapy. The patient’s inflammatory markers decreased on tocilizumab, and his sensorineural hearing loss was notable for improvement and stabilisation on therapy.

Coding joint: kappa-deleting recombination excision circle ratio and B cell activating factor level: predicting juvenile dermatomyositis rituximab response, a proof-of-concept study

BACKGROUND

This pilot study's primary aim was to determine if oligoclonal B cell expansion in children with Juvenile Dermatomyositis (JDM) predicts response to Rituximab therapy. We evaluated: (1) tissue B cell depletion efficacy by measuring the ratio of Coding joint (CJ) to Kappa-deleting recombination excision circle (KREC) DNA, and (2) serum BAFF level upon B cell recovery.

METHODS

CJ and KREC values were measured via qPCR assessment of serial PBMC stored (- 80 °C) in the CureJM Center's BioRepository. Serum BAFF was quantitated by Mesoscale® technology. Oligoclonal B cell expansion was defined as a CJ:KREC ≥ 8 prior to Rituximab therapy. Detection of a CJ:KREC ratio ≤ 2.5 in the first sample after Rituximab was designated as adequate B cell depletion. A significant clinical response to therapy was defined as improvement in Disease Activity Score (DAS) by at least 2 points on consecutive visits within the first 12 months of therapy.

RESULTS

Six out of nine children with JDM showed oligoclonal B cell expansion prior to Rituximab (CJ:KREC ≥ 8). Of those 6 patients, 4 had evidence of effective B cell depletion after Rituximab (CJ:KREC ≤ 2.5), and all 4 of those subjects displayed a significant clinical response to Rituximab. Serum BAFF level increased in 8/9 children after Rituximab.

CONCLUSIONS

In this proof-of-concept study, JDM patients with oligoclonal B cell expansion prior to Rituximab have more favorable clinical outcomes after Rituximab. We speculate: (1) B cell depletion post-Rituximab predicts JDM clinical response; (2) increased BAFF post-Rituximab may contribute to disease flare.

Rheumatologic diseases in patients with inborn errors of immunity in the USIDNET registry

There is a gap in clinical knowledge regarding associations between specific inborn errors of immunity (IEIs) and rheumatologic diseases. This study reports the frequency of rheumatologic conditions in a large cohort of patients with IEI using the USIDNET (United States Immunodeficiency Network) registry. We used the USIDNET registry to conduct the analysis. We included all IEI patients within the registry for whom a diagnosed rheumatologic disease was reported. The total number of patients with IEI in our query was 5058. Among those, 278 (5.49%) patients had a diagnosis of rheumatologic disease. This cohort included 172 (61.8%) female and 106 (38.2%) male patients. Rheumatologic complications were highest in the interferonopathies (66.6%), autoimmune lymphoproliferative syndrome (ALPS) (13.7%), and immunoglobulin G subclass deficiency (IgGSD) (11.11%). Additionally, disease patterns were noted to be different in various IEI disease groups. Inflammatory myopathies were the most common rheumatologic condition in patients with X-linked agammaglobulinemia (1.65%), Sjogren's syndrome was the most common rheumatologic disease reported in ALPS patients (6.85%), and systemic lupus erythematosus was the most common rheumatologic disease in patients with chronic mucocutaneous candidiasis (CMC) (7.41%). Rheumatoid arthritis (RA) report rate was highest in patients with IgGSD (3.70%), specific antibody deficiency (SAD) (3.66%), and ALPS (2.74%). This study reports that rheumatologic diseases are frequently observed in patients with IEI. The frequency of different rheumatologic conditions was variable based on the underlying diagnosis. Clinicians caring for patients with IEI should be vigilant to monitor for rheumatologic complications. Key Points • The rates of reported rheumatologic diseases in the USIDNET registry are different in individual IEIs. • Further studies are needed to guide clinicians for detecting rheumatologic conditions earlier in patients with IEI.

Clues to Disease Activity in Juvenile Dermatomyositis: Neopterin and Other Biomarkers

Easily accessible biomarkers are urgently needed to evaluate immune activation in Juvenile Dermatomyositis (JDM). The goal of this retrospective study is to define immunological and clinical differences between untreated JDM patients with either normal or elevated (>10 mmol/L) levels of neopterin, a biomarker of macrophage activation. We included all JDM with neopterin data obtained before initiating medical therapy. We assessed T, B, NK cell populations, muscle enzymes, and disease activity scores for skin (sDAS), muscle (mDAS), total (tDAS), the duration of untreated disease, disease course, and myositis-specific antibody (MSA). Seventy-nine percent of 139 untreated JDM patients had elevated serum neopterin. The group with elevated neopterin had significantly more active disease: tDAS 11.9 vs. 8.1 (p < 0.0001), mDAS 5.8 vs. 3.1 (p < 0.0001), sDAS 6.1 vs. 4.9 (p = 0.0002), aldolase 24.0 vs. 7.6 U/L (p < 0.0001), von Willebrand factor antigen (p < 0.0001), and ESR 19.8 vs. 11.5 mm/hr (p = 0.01). The flow cytometry documented both reduced T cells (1494 vs. 2278/mm3, p = 0.008) and NK cells (145 vs. 240/mm3, p = 0.003). TNFα-308AA/AG polymorphism was more common in children with elevated neopterin than TNFα-308GG (p 0.05). We conclude that the availability of neopterin data will contribute to the rapid assessment of untreated JDM disease activity.

Changes in total body fat and body mass index among children with juvenile dermatomyositis treated with high-dose glucocorticoids

OBJECTIVE

High-dose glucocorticoids (GC) remain the primary therapy to induce remission in Juvenile Dermatomyositis (JDM). Studies of the natural history of GC associated weight gain in children are very limited, especially in the JDM population. This study aims to measure BMI changes in a cohort of JDM subjects over 60 months and to examine the changes in body composition by DXA.

METHODS

We included all subjects with JDM who had 5 years of follow-up data and multiple DXA studies. BMI and total body fat (TBF) percentiles were calculated based on the CDC published percentile charts. To study the natural history of weight gain and TBF, we assessed the data at four-time points (T0 = baseline, T1 > 1.5 years, T2 = 1.51-3.49 years, T3 = 3.5-5 years).

RESULTS

68 subjects (78% female, 70% white) were included in this retrospective study. Paired T-test showed a significant increase in the mean BMI percentile by 17.5 points (P = 0.004) after the initiation of medical treatment, followed by a gradual decrease over the study period. However, the TBF percentile did not change over the study period. TBF in the last visit (T3) had a strong correlation with the T1 BMI, and T1 TBF percentile (correlation coefficients 0.63, 0.56 P < 0.001, 0.002 respectively). Also, there was a positive correlation (correlation coefficients 0.39, P = 0.002) between the TBF percentile and muscle DAS but not the skin DAS.

CONCLUSIONS

Although the BMI percentile decreased throughout the study, the TBF percentile remained high until the end of the study (60 months). This finding raises the concern that some of the reduction in the BMI percentile could reflect a drop in the lean body mass from muscle wasting rather than actual fat loss.

Studies of 96 children with Juvenile Dermatomyositis: P155/140, is associated with loss of nailfold capillaries, but not generalized lipodystrophy

OBJECTIVE

Myositis-specific antibodies (MSA) facilitate grouping children with Juvenile Dermatomyositis (JDM) into distinct phenotypes. Aim one of this study investigates the link between anti-P155/140 and lipodystrophy as determined by DXA assessment of fat distribution. Aim two examines the relationship between anti-P155/140 and damage to the nailfold capillary system.

METHODS

Children with JDM followed for a minimum of five years were included. The study population was divided into three groups (anti-P155/140, other MSA, and MSA negative). Lipodystrophy was assessed by physician assessment and DXA fat distribution (Trunk:Leg fat ratio). Documentation of nailfold capillary end-row loops (ERL) was obtained at diagnosis RESULTS: 96 subjects (44% anti-P155/140, 23% other MSA, 33% MSA negative) were included. There was no significant difference in age, disease activity scores or lipodystrophy between the three groups. The Trunk:Leg fat ratios were similar among the three groups at different time points. However, the anti-P155/140 group had significantly decreased (ERL) count (p-value = 0.006) at baseline as well as a prolonged duration of untreated disease at diagnosis (p-value = 0.027). Also, the anti-P155/140 group has fewer patients with monophasic disease course than the other two groups (p-value = 0.008) CONCLUSIONS: Generalized lipodystrophy frequency was equivalent in all three groups based on physician assessments and Trunk:Leg fat ratios. The anti-P155/140 group had a greater loss of ERL, suggesting that this MSA may impact the vascular component of JDM.

Evidence for Resident Memory T cells in Rasmussen Encephalitis

Investigators from University of California Los Angeles studied the presence of different T cell subset population in the brain tissue of 7 patients with Rasmussen encephalitis, a rare neuroinflammatory disorder characterized by intractable seizures and usually associated with progressive hemi cerebral atrophy, who underwent brain surgery and compared them to patients with focal cortical dysplasia.

A pilot study of omalizumab in eosinophilic esophagitis

Eosinophilic disorders of the gastrointestinal tract are an emerging subset of immune pathologies within the spectrum of allergic inflammation. Eosinophilic Esophagitis (EoE), once considered a rare disease, is increasing in incidence, with a rate of over 1 in 10,000 in the US, for unknown reasons. The clinical management of EoE is challenging, thus there is an urgent need for understanding the etiology and pathophysiology of this eosinophilic disease to develop better therapeutic approaches. In this open label, single arm, unblinded study, we evaluated the effects of an anti-IgE treatment, omalizumab, on local inflammation in the esophagus and clinical correlates in patients with EoE. Omalizumab was administered for 12 weeks to 15 subjects with long standing EoE. There were no serious side effects from the treatment. Esophageal tissue inflammation was assessed both before and after therapy. After 3 months on omalizumab, although tissue Immunoglobulin E (IgE) levels were significantly reduced in all but two of the subjects, we found that full remission of EoE, which is defined as histologic and clinical improvement only in 33% of the patients. The decrease in tryptase-positive cells and eosinophils correlated significantly with the clinical outcome as measured by improvement in endoscopy and symptom scores, respectively. Omalizumab-induced remission of EoE was limited to subjects with low peripheral blood absolute eosinophil counts. These findings demonstrate that in a subset of EoE patients, IgE plays a role in the pathophysiology of the disease and that anti-IgE therapy with omalizumab may result in disease remission. Since this study is open label there is the potential for bias, hence the need for a larger double blind placebo controlled study. The data presented in this pilot study provides a foundation for proper patient selection to maximize clinical efficacy.