[Blood eosinophilia in patients with severe bronchial asthma and chronic polypous rhinosinusitis treated with dupilumab: A review].

Bronchial asthma and chronic polypous rhinosinusitis are diseases associated with a T2-inflammatory immune response. These nosologies can be combined, creating the preconditions for a more severe course of multimorbidity, requiring the use of genetic engineering biological therapy. Dupilumab is a monoclonal antibody that can specifically bind to the alpha subunit of the interleukin-4 receptor and block the action of interleukins 4 and 13, which play a key role in the development of T2 inflammation. Numerous studies have demonstrated the high effectiveness of this medicament. The use of dupilumab in some cases may be accompanied by an increase in eosinophils in the blood. This article presents scientific base and our own experience in treating patients with dupilumab-associated eosinophilia, in addition we describe an algorithm for examining this group of patients for the purpose of timely diagnosis of diseases such as eosinophilic granulomatosis with polyangiitis, eosinophilic pneumonia, etc. It should be noted that in the most cases eosinophilia during targeted therapy with dupilumab is temporary and does not cause clinical manifestations.

Heparin-induced DRESS syndrome in a paediatric patient and successful anaesthetic management in cardiovascular bypass surgery: case report.

BACKGROUND: Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) Syndrome is a severe adverse drug reaction marked by delayed hypersensitivity reactions causing skin and systemic complications. DRESS diagnosis is challenging due to the variety of clinical presentations and symptom overlap with other conditions. The perioperative period in these patients requires precise pharmacological strategies to prevent complications associated with this syndrome. The treatment of DRESS induced by unfractionated heparin during cardiopulmonary bypass (CPB) surgery presents some challenges that must be considered when selecting an anticoagulant to avoid side effects. In this case, bivalirudin, a direct thrombin inhibitor, is indicated as an alternative to heparin in patients undergoing CPB. However, in contrast to heparin/protamine, there is no direct reversal agent for bivalirudin. CASE PRESENTATION: We report the case of an 11-year-old male diagnosed with native aortic valve endocarditis and thrombosis in his left lower extremity. During valvular replacement surgery, systemic unfractionated heparin was administered. Postoperatively, the patient developed fever, eosinophilia and pruritic rash. Warm shock and elevated alanine transaminase (ALT) and aspartate transaminase (AST) levels followed, leading to the diagnosis of DRESS syndrome. Treatment with methylprednisolone resulted in complete resolution of symptoms. Seven years later, the patient was readmitted due to insufficient anticoagulation and a thrombus in the prosthetic aortic valve, presenting a recurrent DRESS episode due to the administration of unfractionated heparin, which was later replaced with low-molecular-weight heparin during hospitalization. Treatment with corticosteroids and antihistamines was initiated, resulting in the resolution of this episode. Ultimately, the patient required the Ross procedure. During this intervention the anticoagulation strategy was modified, unfractionated heparin was replaced with bivalirudin during the procedure and fondaparinux was administered during the postoperative period. This resulted in stable transaminases levels and no eosinophilia. CONCLUSION: The severity of DRESS Syndrome underscores the importance of early recognition, heightened monitoring, and a comprehensive approach tailored to each patient's needs. This particular case highlights the significance of this approach and may have a substantial clinical impact since it provides alternatives to heparin, such as bivalirudin and fondaparinux, in the anticoagulation strategy of CPB for patients who have a hypersensibility reaction to this medication; thus, enhancing clinical outcomes by minimizing risks linked to adverse drug reactions.

Butyrate inhibits type 2 inflammation in eosinophilic chronic rhinosinusitis.

Butyrate and other Short-chain fatty acids (SCFAs) are microbial metabolites from Bacteroides and Clostridium species that may suppress type 2 inflammation. However, the mechanisms of SCFAs in the nasal sinuses are not fully understood. We aimed to clarify the in vitro and in vivo roles of SCFAs in eosinophilic chronic rhinosinusitis (ECRS) pathophysiology. We investigated whether SCFAs induced changes in type 2 cytokines, IgE, and apoptosis and the roles of GPR41, GPR43, and histone deacetylase. Analysis of the control subjects demonstrated that butyrate of SCFAs effectively inhibited type 2 cytokine production in PBMCs, ILC2s, and CD4+ T cells and IgE production in CD19+ B cells. In annexin V analysis, butyrate also induced late apoptosis of PBMCs. The butyrate-induced inhibition of type 2 cytokines appeared involved in histone deacetylase inhibition but not in GPR41 or GPR43. In an analysis of ECRS in humans, butyrate inhibited type 2 cytokine production in PBMCs and nasal polyp-derived cells. The butyrate concentration in nasal lavage fluid was significantly decreased in ECRS patients compared to controls and non-ECRS patients. Our findings confirm that butyrate can inhibit type 2 inflammation and may be a potential therapeutic target for ECRS.

Severe Asthma or Chronic Obstructive Pulmonary Disease with Eosinophilic Inflammation? From Uncertainty to Remission under Anti IL-5R Therapy.

Background and Objectives: Severe adult-onset eosinophilic asthma and COPD with eosinophilic inflammation are two entities with a similar clinical course and are sometimes difficult to differentiate in clinical practice, especially in patients with a history of smoking. Anti-IL-5 or -IL-5R biological therapy has been shown to be highly effective in severe eosinophilic asthma but has not demonstrated significant benefit in patients with COPD with the eosinophilic phenotype. Our aim was to illustrate this issue in the form of a case report. Materials and Methods: We present the case of a 67-year-old patient who is a former smoker with late-onset severe uncontrolled asthma (ACT score < 15) who experienced frequent exacerbations requiring treatment with systemic corticosteroids. The patient's lung function gradually worsened to a nadir FEV1 = 18%, despite a high dose of ICS in combination with a LABA and intermittent courses of OCS, with negative allergic skin-tests, but with high blood eosinophils level. Biological treatment with an anti-IL5R monoclonal antibody (benralizumab) was initiated, despite the difficulty in the differential diagnosis between asthma and COPD with eosinophilic inflammation. Results: The patient's evolution was favorable; clinical remission was effectively achieved with significant improvement in lung function (FEV1 > 100%), but with persistence of residual mild fixed airway obstructive dysfunction (FEV1/FVC < 0.7). The therapeutic response has been maintained to date. Conclusions: Benralizumab was shown to be very effective in a patient with late-onset severe eosinophilic asthma presenting features of chronic obstructive disease-habitual exposure to tobacco and inhaled noxious substances, and persistent airflow limitation on spirometry.

Juvenile eosinophilic fasciitis: a single center case series.

BACKGROUND: Eosinophilic fasciitis (EF) is a rare disease characterized by skin induration and musculoskeletal abnormalities. Diagnostic criteria for EF are based on adult populations. There is a need to expand the literature on EF in children due to limited reported cases and potential differences compared to adults. METHODS: We conducted a retrospective review of medical records for six pediatric patients diagnosed with EF at our institution between November 2011 and April 2023. Inclusion criteria required patients to be under 18 years of age at the time of diagnosis and to have confirmed diagnosis through clinical history, imaging, and histology. RESULTS: Most of our cohort were female (83%) and non-Hispanic white (50%). Age at diagnosis ranged from 4 to 16 years. Duration of symptoms before diagnosis varied from 1 to 12 months. Follow-up periods ranged from 14 to 123 months. Concurrent medical conditions included localized scleroderma, acquired thrombophilia, and juvenile idiopathic arthritis. Patients presented with progressive painful swelling, severe joint limitations, and positive prayer sign. Initial regimens involved corticosteroids and methotrexate. Hydroxychloroquine, immunoglobulin, mycophenolate mofetil, rituximab, and tocilizumab were also used depending on the patient's disease severity and course. CONCLUSIONS: Juvenile EF may manifest as swelling and progressive induration without apparent skin abnormalities. Unlike adult populations, no underlying malignancies or associations with trauma were observed in our cohort. Our cases did not exhibit systemic involvement observed in previous studies on juvenile EF. While non-specific, the prayer sign may aid in early recognition of juvenile EF and help prevent long-term disability.

Eosinophilic enterocolitis: a case report.

BACKGROUND: Eosinophilic enterocolitis is a rare disorder characterized by abnormal eosinophilic infiltration of the small intestine and the colon. CASE PRESENTATION: We report a case of a 29-year-old White man, who presented with an acute bowel obstruction. He had a history of a 2 months non-bloody diarrhea. An abdominal computed tomography (CT) and a MR enterography showed a multifocal extensive ileitis. White blood cell and eosinophilic polynuclei count was elevated (700/mm3). Ileo-colonoscopy showed normal ileum and segmental petechial colitis. Pathology showed a high eosinophilic infiltration in the colon. The patient was treated with steroids, with a clinical, biological and radiological recovery. CONCLUSION: Eosinophilic enterocolitis should be kept in mind as a rare differential diagnosis in patients presenting with small bowel obstruction.

Safety of dupilumab in T2 airways conditions: focus on eosinophilia across trials and real-life evidence.

INTRODUCTION: Dupilumab, a monoclonal antibody targeting the IL-4 receptor alpha subunit, effectively blocks both IL-4 and IL-13 mediated pathways. Its introduction has represented a significant advancement in the treatment of severe asthma and other Type 2 (T2) conditions, including nasal polyps, atopic dermatitis, and eosinophilic esophagitis. To date, Dupilumab has demonstrated optimal efficacy and safety profile. AREAS COVERED: The safety profile of dupilumab has been extensively studied, especially for its effects on blood eosinophil count. Transient eosinophil increase during treatment is typically insignificant from a clinical point of view and related to its mechanism of action. Rare cases of hyper-eosinophilia associated with clinical conditions like eosinophilic granulomatosis with polyangiitis (EGPA) and hypereosinophilic syndrome (HES) have been reported. Those cases are often related to the drug's steroid-sparing effect or the natural trajectory of the underlying disease rather than a direct cause-effect relationship with dupilumab. EXPERT OPINION: The management of hyper-eosinophilia during dupilumab treatment requires comprehensive diagnostic work-up and strict follow-up monitoring for early detection of systemic disease progression in order to avoid unnecessary discontinuation of an effective treatment. This approach highlights the importance of a personalized treatment.

Toxocarosis in a patient with autism spectrum disorder presenting with severe hypereosinophilia and acute respiratory distress: a case report.

A boy with known autism spectrum disorder was transferred to our department due to a rapidly worsening respiratory situation. The patient's history revealed previous treatment with albendazole against a Toxocara infection 2 weeks prior in Poland. Blood analysis showed such severe eosinophilia and markedly elevated levels of IgE that, initially, a hematologic malignancy was suspected. However, diagnostic workup including autoimmune diagnostic, molecular genetic testing, fluorescence in situ hybridization (FISH), bone marrow aspiration, and parasitological testing led to the diagnosis of an insufficiently treated Toxocara infection. Treatment with albendazole and prednisone (six cycles for 4 weeks each) was administered. This treatment regime led to prompt improvement of symptoms and normalization of laboratory findings.

Comparison of the General Characteristics of Patients with Severe Asthma Who Switched from Omalizumab to Mepolizumab versus Patients Who Responded to Omalizumab Treatment: A Real-Life Study.

INTRODUCTION: Severe asthma is characterized by frequent recurrent airway symptoms and exacerbations, and these affect the quality of life. Biological agents can be used in the treatment of patients with severe asthma if the disease cannot be controlled with standard controller treatment. The aim of this study was to compare the clinical characteristics and laboratory data of patients with severe asthma who were switched from omalizumab to mepolizumab and patients with severe asthma who responded to omalizumab. METHODS: The clinical characteristics and laboratory data of patients with severe asthma who responded to omalizumab and switched from omalizumab to mepolizumab were compared retrospectively. RESULTS: Evaluation was made of a total of 79 patients, including 64 omalizumab responders and 15 who switched to mepolizumab from omalizumab. After omalizumab and mepolizumab treatment, the annual number of asthma attacks, the use of oral corticosteroid (OCS), the annual number of hospitalizations, and the eosinophil count significantly decreased (omalizumab: p < 0.001, p < 0.001, p < 0.001, p < 0.001, respectively; mepolizumab: p = 0.001, p = 0.001, p = 0.002, p = 0.001, respectively). After omalizumab treatment, the increase in forced expiratory volume in 1 s (FEV1) (%) and asthma control test (ACT) score were determined to be statistically significant (p < 0.001, p < 0.001, respectively). After mepolizumab treatment, the increase in ACT score was significant (p = 0.003). Drug allergy, chronic sinusitis with nasal polyps (CRSwNP), regular use of OCS, and high baseline eosinophil count (cells/µL) were associated with poor response to omalizumab treatment (odds ratio [OR] = 7.86, p = 0.003; OR = 52.92, p < 0.001; OR = 10.16, p = 0.004; OR = 0.99, p = 0.004, respectively). House dust mite sensitivity and high baseline FEV1 (%) were associated with good response to omalizumab treatment (OR = 0.29, p = 0.041; OR = 1.06, p = 0.03, respectively). The blood eosinophil count had diagnostic value in predicting the nonresponsiveness to omalizumab treatment (area under the curve [AUC]: 0.967, p < 0.001, cut-off: 510). CONCLUSION: A high pretreatment eosinophil count, concomitant CRSwNP, a history of drug allergy, and regular OCS use may be associated with poor response to omalizumab treatment in patients with severe asthma. Depending on the treatment response, treatment switching can be applied between biological agents. The results of the current study should be supported by multicenter studies.

Temporal trends of blood eosinophilia in severe uncontrolled CRSwNP treated with dupilumab: a real-life study.

PURPOSE: Induced eosinophilia is commonly related to dupilumab treatment. We analysed the temporal trends of blood eosinophilia in patients with severe uncontrolled CRSwNP during the first year of treatment with dupilumab in real-life setting to evaluate its correlation with outcomes of response and adverse events (AEs). METHODS: Seventy-four patients with severe uncontrolled CRSwNP treated with dupilumab at our institution were enrolled. At each visit, we evaluated AEC, outcomes of response to treatment and AEs. RESULTS: A significant increase in AEC was observed since the first month with a peak at 3 months; at 12 months, the values returned comparable to those at baseline. A ≥ 50% increase of the baseline AEC with a value greater than 500 cells/mm3 was documented in 38/74 patients (Group A) regardless of the time of observation, whereas in 36/74 patients (Group B), no changes were observed. Analysing the blood eosinophilia trend over time in group A, we observed a temporary eosinophilia with early onset (within 6 months), persistent eosinophilia with early onset, and eosinophilia with late onset. No differences in terms of outcomes of response to treatment or AEs were found between Group A and Group B, or between patients who developed an AEC ≥ 1500 cells/mm3 or not. CONCLUSION: In our series, we observed that an increase in AEC with different temporal trends may be observed in CRSwNP patients during the first year of treatment with dupilumab. In our series, eosinophilia is not correlated with a negative outcome of response to treatment or a risk of AEs.

Dupilumab for relapsing or refractory sinonasal and/or asthma manifestations in eosinophilic granulomatosis with polyangiitis: a European retrospective study.

BACKGROUND: Eosinophilic granulomatosis with polyangiitis (EGPA) is often associated with glucocorticoid-dependent asthma and/or ear, nose and throat (ENT) manifestations. When immunosuppressants and/or mepolizumab are ineffective, dupilumab could be an option. We describe the safety and efficacy of off-label use of dupilumab in relapsing and/or refractory EGPA. PATIENTS AND METHODS: We conducted an observational multicentre study of EGPA patients treated with dupilumab. Complete response was defined by Birmingham Vasculitis Activity Score (BVAS)=0 and prednisone dose ≤4 mg/day, and partial response by BVAS=0 and prednisone dose >4 mg/day. Eosinophilia was defined as an eosinophil count >500/mm3. RESULTS: Fifty-one patients were included. The primary indication for dupilumab was disabling ENT symptoms in 92%. After a median follow-up of 13.1 months, 18 patients (35%) reported adverse events (AEs), including two serious AEs. Eosinophilia was reported in 34 patients (67%), with a peak of 2195/mm3 (IQR 1268-4501) occurring at 13 weeks (IQR 4-36) and was associated with relapse in 41%. Twenty-one patients (41%) achieved a complete response and 12 (24%) a partial response. Sixteen (31%) patients experienced an EGPA relapse while on dupilumab, which was associated with blood eosinophilia in 14/16 (88%) patients. The median eosinophil count at the start of dupilumab was significantly lower in relapsers than in non-relapsers, as was the median time between stopping anti-IL-5/IL-5R and switching to dupilumab. CONCLUSION: These results suggest that dupilumab may be effective in treating patients with EGPA-related ENT manifestations. However, EGPA flares occurred in one-third of patients and were preceded by eosinophilia in 88%, suggesting that caution is required.

Eosinophilic cystitis: a case report of a pseudotumoral lesion.

Eosinophilic cystitis is a rare inflammatory disorder of the bladder, characterized by eosinophilic infiltration of the bladder wall, fibrosis of the mucosa, and muscle necrosis. Ultrasonography, when performed, shows a pseudotumoral mass that can be mistaken for malignancy. We report a case of a woman referred to our department in which an ultrasound showed a bladder mass and the biopsy demonstrated the presence of eosinophilic cystitis. The patient was treated with medical treatment and the outcome was favorable with the disappearance of symptoms and no recurrence at controls. We carry a literature review of cystitis eosinophilic, the ultrasound appearance, and therapeutic modalities.

Cardiac tamponade due to eosinophilia treated with intravenous corticosteroid: A case report.

RATIONALE: Cardiac tamponade, a condition in which the heart is compressed by pericardial fluid retention, is easy to diagnose; however, identifying the cause may be challenging since it can be caused by a variety of conditions, including trauma and pericardial disease. PATIENT CONCERNS: A 22-year-old man was admitted to the intensive care unit with respiratory failure. He had previously received allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia and developed chronic graft-versus-host disease (cGvHD) that was treated with a corticosteroid. At this time, he developed bilateral femur head necrosis and underwent surgery after discontinuation of the corticosteroid but developed respiratory failure postoperatively. The initial diagnosis was cardiac failure, which temporarily improved with treatment; however, eosinophilia and pericardial effusions became prominent. DIAGNOSES: Pericardial effusion gradually progressed, resulting in cardiac tamponade. INTERVENTIONS: Pericardiocentesis was performed. Eosinophilia could be the cause of cardiac tamponade; thus, corticosteroid was administered. OUTCOMES: Pericardial effusion improved remarkably after corticosteroid administration. The corticosteroid dose was gradually tapered, and the patient was discharged. LESSONS: This case presented with cardiac tamponade associated with eosinophilia, probably owing to graft-versus-host disease. This is an unusual condition associated with a history of hematologic neoplasms; although evaluation is challenging, appropriate assessment could help save the patient's life.

Sustained Response to Ruxolitinib of Eosinophilia-Associated Myeloproliferative Neoplasm with Translocation t(8;9)(p21;p24).

The translocation t(8;9) produces the fusion gene PCM1-JAK2, resulting in the continuous activation of the JAK2 tyrosine kinase. Myelodysplastic/myeloproliferative neoplasms are the most common disease with t(8;9)/PCM1-JAK2. Individuals with this abnormality have similar features, and JAK2 kinase inhibitor (ruxolitinib) is an effective treatment of the condition. The long-term remission results of ruxolitinib are varied. It is important to determine the response to ruxolitinib. Here, we describe a patient who has been diagnosed with eosinophilia-associated myeloproliferative neoplasm with t(8;9)(p21;p24). This patient has achieved sustained response for >1 year since the administration of ruxolitinib.

Real-world outcomes of mepolizumab treatment in severe eosinophilic asthma patients - retrospective cohort study in Slovakia.

AIMS: Mepolizumab, a fully-humanized recombinant IgG1 kappa monoclonal antibody directed against IL-5, has shown improved asthma control and lung function in randomised controlled trials. The aim of this study was to evaluate real-world clinical experience in patients with severe eosinophilic asthma treated with mepolizumab in Slovakia. METHODS: A retrospective, non-interventional study based on medical records of all adult asthma patients initiating mepolizumab between November 1, 2017 and January 31, 2019, completing 12 months of treatment. At baseline, general and clinical profile data were recorded 12 months prior to treatment. Primary and secondary endpoints described the results of mepolizumab use at 2, 6, and 12 months after the initiation and compared to baseline. Statistical testing of individual change (in each patient) in selected parameters was performed. RESULTS: The cohort included 17 patients with particularly severe asthma at baseline, with frequent severe exacerbations (SE, median 5 [IQR 4-6]/patient/year), high blood eosinophil counts (median 0.6x109/L), frequent oral corticosteroid (OCS) dependence (82.35%), median dose 15 (IQR 7.5-20) mg/day, impaired lung function, and a spectrum of comorbidities. In a one-year follow-up, the data showed reductions in median SE (0 [IQR 0-1] patient/year, eosinophilia (median 0.175x109/L) and OCS maintenance dose (median 6.25 [IQR 2.5-20] mg/day), all statistically significant after 12 months on mepolizumab. Improved and stabilised lung functions throughout the cohort and a reduced incidence of nasal polyposis were observed. CONCLUSIONS: The results provide clinical evidence of mepolizumab efficacy in a real sample of patients with severe asthma when administered in routine care settings in Slovakia.

New-onset of eosinophilic granulomatosis with polyangiitis without eosinophilia and eosinophilic infiltration under benralizumab treatment: A case report.

Eosinophilic granulomatosis with polyangiitis (EGPA) is a small- to medium-vessel necrotising vasculitis and eosinophilic inflammation. Mepolizumab, an anti-interleukin-5 (IL-5) monoclonal antibody has been approved in Japan since 2018 for refractory EGPA treatment. Benralizumab, an anti-IL-5 receptor monoclonal antibody, also has been reported to reduce the glucocorticoid dose in patients with refractory EGPA. On the other hand, several investigators have demonstrated new-onset EGPA under biologics, and it is unclear whether this treatment for severe allergic diseases can prevent the development of EGPA. Herein, we report a case of new-onset EGPA under benralizumab treatment. The patient had fever, weight loss, muscle pain, and paraesthesia, the serum eosinophil count was 0/µL, and the biopsy showed necrotizing vasculitis without eosinophilic infiltration. She was diagnosed as having EGPA and treated with high-dose glucocorticoid and intravenous cyclophosphamide, with a good response. Our case report indicates that anti-IL-5 agents may mask the development of EGPA and clinicians should be aware of the development of EGPA during anti-IL-5 agents.

[Experience of biological therapy in severe forms of chronic rhinosinusitis with nasal polyps in the conditions of regional healthcare]. / Opyt biologicheskoi terapii pri tyazhelykh formakh khronicheskogo polipoznogo rinosinusita v usloviyakh regional'nogo zdravookhraneniya.

Recurrent chronic rhinosinusitis with nasal polyps (CRSwNP) with a predominant Th2 endotype of inflammation, including associated with bronchial asthma and/or allergic rhinitis, aspirin triad, refers to diseases with an insufficient level of control, despite the use of a wide range of options for conservative and surgical treatment. OBJECTIVE: To analyze our own experience, clinical and organizational features of the application of the method of biological therapy in patients with severe forms of recurrent CRSwNP. MATERIAL AND METHODS: 25 patients with severe and moderate forms of CRSwNP were examined, who, in a round-the-clock hospital (model CSG 36.018) was treated with Dupilumab, in the form of subcutaneous injections of 300 mg/2 ml 1 every two weeks. The diagnosis was confirmed on the basis of anamnestic data, SNOT-22 quality of life questionnaires, visual endoscopic examination, evaluation of CT data (Lund-Mackay scale), laboratory data. The effectiveness of treatment was monitored after 16 weeks, based on endoscopic examination data, evaluation of CT and SNOT-22 data. In 3 observations, a study of pathomorphological material for tissue eosinophilia was performed. RESULTS: The duration of the course of treatment ranged from 10 to 56 weeks. The most striking clinical effect was observed for signs such as sense of smell and nasal breathing (in some cases-after the first injection). The degree of regression of polyps according to CT and endoscopic examination was more prolonged in time, the same dynamics was observed in the level of total IgE. In a number of patients, the phenomenon of eosinophilia growth was observed against the background of treatment (with regression of clinical symptoms). Pathomorphological examination confirmed a high level of tissue eosinophilia as one of the fundamental signs of Th2 inflammation. One patient with concomitant chronic tubar dysfunction had an improvement in hearing. All patients with AD noted a subjective improvement in disease control (a decrease in the frequency and severity of choking attacks). The cancellation (break in treatment) of treatment was accompanied by a gradual return of symptoms in all patients at various times. CONCLUSIONS: Patients who have not achieved an acceptable level of control of CRSwNP,that meets the criteria of Th2 inflammation can be considered as candidates for the use of targeted biological therapy. With strict compliance with the selection criteria, there is a good clinical effect, primarily in relation to nasal symptoms (sense of smell and nasal breathing) and improved control of asthma symptoms.

An eosinophil peroxidase activity assay accurately predicts eosinophilic chronic rhinosinusitis.

BACKGROUND: A definitive diagnosis of eosinophilic chronic rhinosinusitis (eCRS) requires invasive surgical tissue sampling and histologic enumeration of intact eosinophils. Eosinophil peroxidase (EPX) is an accurate biomarker of sinonasal tissue eosinophilia in CRS regardless of polyp status. A less invasive and rapid method that accurately identifies tissue eosinophilia would be of great benefit to patients. OBJECTIVE: We sought to evaluate a new clinical tool that uses a nasal swab and colorimetric EPX activity assay to predict a diagnosis of eCRS. METHODS: A prospective, observational cohort study was conducted using nasal swabs and sinonasal tissue biopsies obtained from patients with CRS electing endoscopic sinus surgery. Patients were classified as non-eCRS (n = 19) and eCRS (n = 35) on the basis of pathologically determined eosinophil counts of less than 10 or greater than or equal to 10 eosinophils/HPF, respectively. Swab-deposited EPX activity was measured and compared with tissue eosinophil counts, EPX levels, and CRS-specific disease metrics. RESULTS: EPX activity was significantly increased in patients with eCRS than in patients without eCRS (P < .0001). With a relative absorbance unit cutoff value of greater than or equal to 0.80, the assay demonstrated high sensitivity (85.7%) and moderate specificity (79.0%) for confirming eCRS. Spearman correlations between EPX activity and tissue eosinophil counts (rs = 0.424), EPX levels (rs = 0.503), and Lund-Kennedy endoscopy scores (rs = 0.440) in eCRS were significant (P < .05). CONCLUSIONS: This investigation evaluates a nasal swab sampling method and EPX activity assay that accurately confirms eCRS. This method could potentially address the unmet need to identify sinonasal tissue eosinophilia at the point-of-care, as well as to longitudinally monitor eosinophil activity and treatment response.