MATERIAL AND METHOD
Patients between 5-18 years of age and applied to the outpatient clinics of Pediatric Pulmonary Diseases with the diagnosis of non-cystic fibrosis bronchiectasis and osteoporosis were included in the study. Patients presented to the outpatient clinics of pediatric for routine follow-up with no chronic disease were included as the control group. DEXA measurement was performed in order to evaluate the bone mass of patients with bronchiectasis.
BMD value measured by DEXA is expressed by Z and T scores. Comparison of the measured bone mass with reference values according to age and gender and definition of it as standard deviation is the Z score. The standard deviation of comparison of the bone mass with the mean bone mass of the young adult reference population is the T score. BMD measured in children is evaluated as Z score. The length of the measured bone in addition to the height, pubertal phase, skeletal maturation, race and body composition is considered in order to correctly interpret the data obtained by DEXA method (8). Another method of evaluation in children is QUS (9).
Ethics board approval was obtained from the Ethics Board Committee dated January 8, 2016, and numbered 2016/399. An informed consent was obtained from all patients included in the study after explaining the aim and extent of the project in detail to each of them.

Collection and Storage of Samples and Study Method

Blood samples obtained were centrifuged at a cooling centrifugation device with the trademark Hettich Rotina 46R (HettichZentrifugen, Tuttlingen , Germany) at 4000 cycles/minute for 10 minutes and the sera were separated. Serum samples were stored in New Brunswick U570 (New Brunswick Scientific, New Jersey, ABD) refrigerator at -80°C. Enzyme Linked Immunosorbent Assay (ELISA) method was used in the serum samples using human RANKL (Biovendor Research and Diagnostic Products Karasek, The Czech Republic), OPG Biovendor Research and Diagnostic Products Karasek, The Czech Republic, bALP (Quidel Corporation, San Diego, USA), OST (Biovendor Research and Diagnostic Products Karasek, The Czech Republic), NTX (Alere Scarborough, Scarborough, USA) kits.
The results were calculated according to the absorbance concentration calibration graphics using Biotek ELX 50 microplate washer (BioTek Instruments, Vermont, USA) and Bio-rad Microplate absorbance reader xMark (Bio-rad Laboratories, California, USA ) system.