ASSESSMENT OF CYTOKERATIN 19 AS A SEVERITY MARKER IN SERUM AND EXHALED BREATH CONDENSATE IN CHILDHOOD INTERSTITIAL LUNG DISEASES AND ITS CORRELATION WITH THEIR CLINICAL AND FUNCTIONAL GRADING

Abstract

SUMMARY C hildhood Interstitial Lung Disease (chILD) is a group of diverse, chronic respiratory disorders characterized by abnormal gas exchange, the presence of diffuse infiltrates on chest radiographs and abnormal pulmonary function tests with evidence of a restrictive ventilatory defect. The elevated serum levels of cytokeratin 19 might indicate the degree of activity of those diseases, and might be useful in the prediction of prognosis especially in patients with IPF and CDPF. The aim of this study was to assess the role of cytokeratin 19 in serum and exhaled breath condensate as a marker of severity of ChILD and to correlate it with dyspnea score, ILD score, HRCT score and pulmonary function tests. Our study group was randomly selected from Pediatric Chest clinic, Children’s Hospital, Ain Shams University. It included 40 patients with interstitial lung diseases and 40 age and sex matched healthy children as control. Patients with ILD were subdivided into 2 groups according to the possible etiology of ChILD; (Group I): due to environmental exposure or genetic cause and (Group II): due to systemic disease. Group I included 26 patients (65%) with environmental exposure to birds, industries, passive smoking, farms, animals, paints and fire smoke. Group II included 14 patients (35%) with systemic diseases including systemic lupus erytheromatosis, Hermansky-Pudlak syndrome, Churg strauss and immunodeficiency. The patients included in our study were 16 males (40%) and 24 females (60%), their age ranged from 5 to 15 years with mean of age 9.70±3.13 years. The mean duration of symptoms in children with ILD was 3.98±3.11 years (ranging from 0.5 to 12years) with 14 children (35%) having their onset of symptoms before 2 years of age and 26 children (65%) having their onset of symptoms after 2 years of age. The most frequent symptom among the studied patients was cough (85%), followed by dyspnea (75%), exercise intolerance (70%), recurrent chest infection (50%), chest pain (20%) and expectoration (10%). Regarding the physical signs, tachypnea was the most common sign (85%) followed by crackles (70%), clubbing (60%), cyanosis (25%), failure to thrive (20%), wheezes (20%), accentuated second heart sound (15%) and corpulmonale and heart failure (10%). The frequency of hospital admission in our study group ranged from 0 to 7 times with a mean of 1.80 ± 1.91. Based on the history taken by the MRC questionnaire, our patients were given a dysnea score of 0 for 4 patients (10%), score 1 for 10 patients (25%), score 2 for 8 patients (20%), score 3 for 8 patients(20%), score 4 for 8 patients (20 %),and score 5 for 2 patients (5%). The difference between group I and II was not statistically significant (P= 0.253). Oxygen saturation of our patients ranged from 69 to 99 with a mean of 93.75±7.37. 8 patients (20%) were desaturated at rest (ILD score ≥ 4), 8 patients (20%) became desaturated after 6 minute walk exercise (ILD score =3) and 24 patients (60%) were normoxemic under all conditions (ILD score≤ 2). The difference in oxygen saturation between group I (mean±SD, 92.62±8.78) and group II(mean±SD, 95.86±3.13) was not statistically significant (P=0.36). Six patients (15%) had pulmonary hypertension by echocardiography (ILD score= 5). Thirty % of our patients had normal chest x-ray meanwhile they had positive findings in HRCT. The chest x-ray of the rest of the patients showed reticulonodular pattern in 28 patients (70%), increased bronchovascular markings in 8 patients (20%), honey comb appearance in 4 patients (10%), hilar lymph node in 2 patient (5%) and eventration of diaphragm as an association in 1 patient (5%).