A Study of the Relationship Between Allergy and Immune Thrombocytopenia in Pediatrics

Abstract

Immune thrombocytopenia (ITP) is the most common hematologic autoimmune disease in children and adults. ITP of childhood is characterized by (platelet count <100,000 m/l with normal white blood count and hemoglobin. ITP resolves spontaneously within 3 months and 30 percent of affected children will go on to have chronic ITP. In ITP, normal platelets are destroyed most often in response to an unknown stimulus this may occur in isolation (primary ITP) or in association with other disorders (secondary). There are increasing reports on the appearance of allergies concomitantly with autoimmunity, but the relationship is poorly understood. Allergy and autoimmunity are two potential outcomes of dysregulated immunity both are characterized by localized inflammation that leads to the injury and/or destruction of target tissues. Until recently it was generally accepted that the mechanism that govern these disease processes are quite disparate, however, new discoveries suggest possible pathogenetic linkage. The aim of our study was to evaluate the relation between ITP and allergy in children by questionnaire for allergic manifestation and measuring serum IL31 and serum IgE. This work was conducted on 62 ITP patients from those regularly attending pediatric hematology and oncology clinic pediatric hospital, Ain Shams University. All studied patients were subjected to the following: detailed history taking clinical examination, questionnaire for allergy, CBC, measuring IgE level by commercially available RAST method and measuring IL31 level analysis of sample was done using ELISA technique. This study included 33 male and 29 female with male to female ration (1:0.88), 36 had chronic ITP and 26 had acute ITP with ratio (1:0.72). Range of age of was 1year-18years (<2 years = 5 cases, (2years - 5years) = 18 cases, (5 years- 10years) = 13 cases and (> 10years) = 26 cases) and the median was 6years with interquartile range (3,5-13 years). Patients were compared with 10 healthy subject served as a controls, the control group consisted of 8 males and 2 females with male to female ratio (1: 0.25) and range of age (0,5 years – 12 years), the median age of controls was 2years with interquartile range ( 3 – 10years). Collected data were reviewed coded and statistical analysis was done which revealed that: There was a higher level of IL31 level detected in cases of ITP when compared to healthy control group with cut-off value was found >1.7 ng/ml with sensitivity 95.16% and specificity 80%. There was statistically significant higher score of allergy in ITP patients compared to control group. Also there was statistically significant higher score of IL31 level in allergy positive score patients compared to allergy negative score patients. There is statistically significant longer duration of ITP in steroid resistant group in comparison to steroid responsive group. Also, there was statistically significant positive correlation between IL31 level and score of allergy. There was no statistically significant correlation between IgE level and score of allergy.