Evaluation of eosinophil-to-lymphocyte ratio before and after immunotherapy in pediatric allergic rhinitis patients

Alper Yenigun; Nurtac Dagistanli; Emre Polat; Remzi Dogan; Mustafa Atilla Nursoy; Orhan Ozturan

doi:10.4103/sjoh.sjoh_11_23

ORIGINAL ARTICLE

Year : 2023 | Volume : 25 | Issue : 1 | Page : 24-28

Evaluation of eosinophil-to-lymphocyte ratio before and after immunotherapy in pediatric allergic rhinitis patients

Alper Yenigun¹, Nurtac Dagistanli¹, Emre Polat¹, Remzi Dogan¹, Mustafa Atilla Nursoy², Orhan Ozturan¹
¹ Department of Otorhinolaryngology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey
² Department of Pediatric Allergy, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey

Date of Submission	11-Feb-2023
Date of Decision	26-Feb-2023
Date of Acceptance	27-Feb-2023
Date of Web Publication	29-Mar-2023

Correspondence Address:
Dr. Emre Polat
Department of Otorhinolaryngology, Faculty of Medicine, Bezmialem Vakif University, Istanbul 34093
Turkey

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/sjoh.sjoh_11_23

Abstract

Objective: The aim of this study is to calculate the eosinophil-to-lymphocyte ratio (ELR) before and after the treatment with subcutaneous immunotherapy (SCIT) and to investigate if ELR decreases after the treatment. The results will support our hypothesis of using the ELR as a diagnostic and prognostic parameter in allergic rhinitis (AR) patients. Study Design: This study was planned and performed as a case–control study. Materials and Methods: In this prospective study, we have collected the data from 68 pediatric patients (aged between 9 and 18 years) who have been treated with 4-year SCIT and whose skin prick test was negative after treatment of AR. ELRs were compared based on the hemogram results before SCIT and approximately 4 years later. Patients who have the inflammatory disease were eliminated from the study since lymphocytes were increased in the blood biochemistry tests. Results: When the eosinophil counts were compared before and after the immunotherapy, it was observed that the eosinophil ratios were decreased from 7.14 ± 4.63 to 4.55 ± 2.98; (P = 0.000) after treatment. Lymphocyte count also decreased from 34.8 ± 10.3 to 32.9 ± 8.3 (P = 0.091). After SCIT, ELRs were significantly lower (P < 0.001). While the mean ± standard deviation (SD) value of ELR was 0.18 (0–0.66) before the treatment, the mean ± SD value after SCIT was 0.11 (0.01–0.67). Total immunoglobulin E decreased from 96.9 ± 10 to 82 ± 11, which was not statistically significant (P = 0.058). Conclusion: A statistically significant decrease in ELR was observed in patients whose skin prick test was negative after immunotherapy. ELR would be as valuable as a skin prick test for diagnostic and prognostic purposes.

Keywords: Allergic rhinitis, allergy, eosinophils, lymphocytes, skin tests

How to cite this article:
Yenigun A, Dagistanli N, Polat E, Dogan R, Nursoy MA, Ozturan O. Evaluation of eosinophil-to-lymphocyte ratio before and after immunotherapy in pediatric allergic rhinitis patients. Saudi J Otorhinolaryngol Head Neck Surg 2023;25:24-8

How to cite this URL:
Yenigun A, Dagistanli N, Polat E, Dogan R, Nursoy MA, Ozturan O. Evaluation of eosinophil-to-lymphocyte ratio before and after immunotherapy in pediatric allergic rhinitis patients. Saudi J Otorhinolaryngol Head Neck Surg [serial online] 2023 [cited 2023 Jun 4];25:24-8. Available from: https://www.sjohns.org/text.asp?2023/25/1/24/372815

Introduction

Allergic rhinitis (AR) is a type of nasal inflammation that occurs when the immune system shows type 1 hypersensitivity reaction to air allergens. The most common allergens are dust, pollen, straw, mold spores, and animal hairs that trigger AR after exposure. Symptoms typically include sneezing, runny nose, itchy nose, and congested nose. Eosinophils, basophils, and immunoglobulin E (IgE) in mast cells are involved in this reaction. AR affects 10%–30% of adults; however, the incidence in children is 10%–40% and is most common in children and adolescents.^[1] The increase in AR among children has become more important in the industrialized world. Therefore, diagnosing AR early in childhood is becoming more important, and it is based on medical history and physical examination. Skin prick test has consequently become the gold standard test in the detection of type 1 hypersensitivity to allergens, and therefore, it is the most common diagnosis method to define the presence of an allergy and identify responsible allergens.

Subcutaneous immunotherapy (SCIT) is recommended in patients whose symptoms do not regress despite medical treatment.^[2] SCIT is a safe and effective method in the treatment of AR and allergic asthma that reduces symptoms and the need for medication.^[3] The mechanism of SCIT is early desensitization of mast cells and basophils, increased formation of regulatory T- and B-cells, and regulation of IgE and IgG4. Furthermore, SCIT reduces the number of mast cells and eosinophils in the mucosal tissue.^[4] Skin prick test is commonly used to demonstrate the efficiency of immunotherapy treatment. The skin prick test indirectly measures the allergen-specific IgE due to mast cells of the skin which regresses after the immunotherapy treatment.^[5],[6] The skin prick test is commonly used due to its rapid test results. On the other hand, it has limited results in patients with dermography or antihistamines.^[7] The diagnostic value of the skin prick test is particularly limited in the diagnosis of food allergy.^[8] Another disadvantage of the prick test is that the reaction considered positive is dependent on the subjective assessment of the tester. Some results are compared with histamine reaction, while others are measured by the diameter of the reaction.^[9] Therefore, a cutoff value such as IgE was used; however, some results were found to vary, especially in food allergies.^[10]

In our previous study,^[11] we showed that a high eosinophil-to-lymphocyte ratio (ELR) was observed in AR patients with positive skin prick tests with ELR objectivity and rapid results.^[11] In this study, we wanted to demonstrate ELR values in sensitized and symptomatic pediatric patients in the previous study whose skin test turned negative after SCIT.

Materials and Methods

This was a prospective study approved by the Institutional Ethical Board for Clinical Research (January 22, 2019; decision number 02/17). Written informed consent was obtained from the parents of the patients.

Our previous study included 695 children (316 girls, 45.5%; 379 boys, 54.5%) who were treated in our clinic from July 2014 to January 2015. The patients were divided into the following four groups: Group 1 (nonsensitized asymptomatic) (control group) included 237 healthy children (131 boys, 106 girls; age, 5–15 [average, 7.74] years), Group 2 (nonsensitized symptomatic) included 216 children with AR (97 boys, 119 girls; age, 5–15 [average, 8.38] years), Group 3 (sensitized asymptomatic) included 98 children with AR (68 boys, 30 girls; age, 5–15 [average, 8.62] years), and Group 4 (sensitized symptomatic) included 144 children with AR (83 boys, 61 girls; age, 5–15 [average, 9.52] years) [Table 1].

Table 1: Demographic of the groups before immunotherapy

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In this study, immunotherapy was planned for 144 patients who were sensitized and symptomatic in the previous study. We carried out retrospectively between November 2014 and July 2018. Indications of allergen immunotherapy were recorded along with the age, gender, additional diseases, and medications of the patient. Seventy-six patients who did not complete the immunotherapy, or whose skin prick test did not turn negative did not meet the criteria for giving a blood sample and were excluded from the study. The remaining 68 children (39 boys and 29 girls; age, 5–18 [average, 8.42] years) from Group 4 (sensitized and symptomatic) who had SCIT were included in the study [Table 2]. Immunotherapy was applied for an average of 30–48 months, different for each patient. Immunotherapy was continued until the skin prick test became negative.^[12]

Table 2: Sensitized and symptomatic patients before and after immunotherapy

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Eosinophil, lymphocyte, and ELR were measured from hemograms of patients who have been treated with immunotherapy and showed negative skin prick test results.

Before the assessment of the hemogram, it was confirmed that short-acting antihistamines were stopped at least 5 days before, long-acting antihistamines were stopped at least 2 months before and H2-receptor blockers were discontinued at least 24 h. In addition, patients who used nonsteroidal anti-inflammatories, a bronchodilator, corticosteroids, mast cell stabilizers, and immunosuppressant drugs during the study month were excluded from the study. The eosinophil, lymphocyte, and ELR counts obtained from the hemogram were compared to the values before the immunotherapy therapy. A significant difference between the groups was searched between two groups.

Skin prick test

Standard Alyostal ST® (Stallergenes S.A. France) were used for skin-prick tests. Allergen extracts were drawn into Quick test applicators with eight heads and applied to the skin on the ventral side of the forearm after cleansing of the testing site with alcohol. Topical histamine hydrochloride was used as a positive control and isotonic NaCl as a negative control. The results were read 15 min after application. Test validity criteria were set as >3 mm for positive controls and <3 mm for negative controls. A skin reaction with an induration of ≥3 mm was accepted as positive.^[13] Fourteen common allergens plus a negative and positive control were applied to the skin of the forearm using two eight-headed applicators.

Eosinophil-to-lymphocyte ratio

Blood samples were obtained from all patients for a complete blood count at admission. The samples underwent automated differential counts using a Sysmex XT 2000i (Kobe, Japan); these yielded the total white blood cell, neutrophil, and lymphocyte counts per microliter. The ELR was calculated for each patient by dividing the number of eosinophils by the number of lymphocytes: ELR = eosinophils (10³ μL)/lymphocytes (10³ μL).^[14]

Statistical analysis

The Number cruncher statistical system 2007 and Power Analysis and Sample Size 2008 Statistical Software (Statistical Software, Utah, USA) programs were employed for evaluating the data gathered in the study. Besides using descriptive statistics (mean, standard deviation) in evaluating the data, the two-sample t-test was used for comparing the quantitative data, and for comparing the normally distributed parameters between the groups. The significance level was set at P < 0.001 and P < 0.05.

Results

A total number of 68 patients were included in the study. Thirty-nine were male (57.3%) and 29 were female (42.7%). The age range was from 9 to 18, and the mean age was found as 14.9. The distribution of the results was followed as a standard normal distribution. When the results of immunotherapy were compared before and after, the eosinophil count decreased from 7.14 ± 4.63 to 4.55 ± 2.98 (P = 0.001) with a statistically significant value [Figure 1]. Lymphocyte count was decreased from 3.48 ± 10.3 to 3.29 ± 8.3, which was not found to be statistically significant (P = 0.091) [Figure 2]. When ELR was calculated, the value was decreased from 0.22 ± 0.15 (before immunotherapy) to 0.14 ± 0.11 (after therapy) as statistically significant (P = 0.001) [Figure 3] and [Table 2].

Figure 1: Eosinophil values before and after immunotherapy

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Figure 2: Lymphocyte values before and after immunotherapy

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Figure 3: ELR values before and after immunotherapy. ELR: Eosinophil-to-lymphocyte ratio

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In 66 (97%) of the patients, Dermatophagoides farinae and Dermatophagoides pteronyssinus were positive in the skin prick test, but 53 (77.9%) patients received immunotherapy for only house dust mite allergy. Nine patients had cat hair, seven patients had grass, and five patients had grain. One patient was positive for dog hair and pollen at the skin prick test [Figure 4].

Figure 4: Allergens variance of the sensitized and symptomatic patients undergoing immunotherapy

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Total IgE was decreased from 96.9 ± 10 to 82 ± 11, which was not found to be statistically significant (P = 0.058).

Discussion

This study is the continuation of our previous study, where we have allocated four groups which are the control group, symptomatic + skin prick test negative group, asymptomatic + skin prick test positive group, and symptomatic + skin prick test positive group with the total number of 695 patients.^[11] When ELR in each group were compared, ELR in Groups 3 and 4 were found to be significantly higher than in Group 1 and Group 2. Therefore, it is shown that ELR value is affected more by patients' skin test sensitivity compared to being symptomatic. Instead of the skin prick test, which is used as an indicator of sensitization, ELR was introduced as a predictive factor. According to this hypothesis, since it is known that a negative skin prick test is used to determine the success of treatment after immunotherapy, ELR is also expected to decrease significantly. In this study, ELR showed a statistically significant decrease from 0.22 ± 0.15 to 0.14 ± 0.11 after immunotherapy and these results indicated the accuracy of the hypothesis (P = 0.001). SCIT is an effective treatment modality in selected patients with AR. There is a heterogeneity about which allergen and which method is used.^[15] As in our study, patients are sensitized to different allergens, such as cat hair, grass, grain, pollen, and dog hair, but most commonly to house dust mites. Since it is known that eosinophil and related mediators are known in the pathogenesis of AR, it is thought that the count of eosinophilia will decrease after SCIT. In 1991, a small number of patients were included in Furin et al.^[16] and the study (n = 25) did not find a significant correlation between the number of eosinophils and immunotherapy. In 2001, Wilson and his friends^[17] compared nasal biopsies taken from 37 patients who had received immunotherapy for 2 years before and after the treatment, and a significant decrease in the number of eosinophils in the tissue was found.

Throughout human life, the account of eosinophils fluctuates in the effect of existing allergens. The memory cells in the peripheral tissue do not accompany these fluctuations. Despite this, they contribute to apoptosis or proliferation of eosinophils by mediators such as interleukin-5.^[18] From this perspective, in our study, there was a significant decrease in the number of eosinophils after allergen immunotherapy, whereas the decrease in the number of lymphocytes was not statistically significant. ELR forms the basis of different studies related to AR. Brescia et al.^[19] compared neutrophil-to-lymphocyte ratio (NLR) and ELR in 115 patients preoperatively and 12 months postoperatively for chronic sinusitis. In this study, subgroups were created, such as allergy, asthma, and eosinophilic nasal polyps; and a statistically significant decrease in postoperative rate was found only in patients with eosinophilic nasal polyps.

Functional endoscopic sinus surgery (FESS) is a treatment modality in patients with nasal polyps that require surgery, and, in this study, immunotherapy is suggested in patients with AR. If the polyp is caused by allergy, both treatment modalities decreased ELR significantly after the treatment. In another study, 240 patients who underwent FESS for nasal polyps were followed for 12 months by Brescia et al.^[20] NLR, ELR, and basophil-to-lymphocyte ratio were significantly higher in patients with nasal polyp recurrence; however, it cannot be used as a differential diagnostic criterion of recurrence. A similar study was carried out by Yenigun.^[20] When the group to be operated on for recurrent nasal polyposis was compared with the group that had no atopic history and had nasal polyps, the ELR and NLR were significantly higher in the recurrent nasal polyp group.^[20]

Dogru et al.^[21] in their study aimed to establish a relationship between AR and NLR in children. Four hundred and thirty-eight children with AR divided into two groups, mild and moderate/severe, were compared with a control group of 180 children. NLR is higher in the AR group than in the control group. Furthermore, NLR in the moderate/severe group increased significantly compared to the mild group.^[21]

As pointed out by the above-mentioned studies, it is thought that ELR can be used as a parameter similar to a skin prick test as an indicator of determining allergen sensitivity, recurrence degree, and severity of AR and related diseases. A significant decrease in eosinophils and ELR after immunotherapy indicates the negativity of the skin prick test. In order to use ELR as a standard sensitization parameter to use for diagnostic and prognostic aims, studies with larger groups of patients are needed. This parameter is inexpensive to measure and easy to use and calculate.

Conclusion

ELR increases have been shown in the positive prick test group compared to the control group. In this study, we have shown that when the patient is treated with SCIT (thus having a negative prick test), the ELR decreases. The results demonstrate that the ELR can be used to show atopy as well as skin prick test in clinical practice.

Ethical approval

All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Informed consent

Informed consent was obtained from all individual participants included in the study.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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