Journal of Genetic Syndromes & Gene Therapy
Open Access
ISSN: ISSN: 2157-7412
ISSN: ISSN: 2157-7412
Daphna Vilozni
Tel-Aviv University, Israel
Posters & Accepted Abstracts: J Genet Syndr Gene Ther
Rationale: Forced vital capacity (FVC) values decrease with progress of the disease in Ataxia telangiectasia (AT). Objective: To study the effect of this process on airway obstruction determination and life span in AT. Methods: Clinical data and yearly best spirometry maneuvers were collected retrospectively from 37 AT patients (196 spirometry tests) during 5.4?±1.8 years (initial age 4-21 years). Twelve patients were walking (7 of them had recurrent respiratory system infections); 25 subjects were confined to wheelchair, of them 8 patients were towards end-stage lung disease. Spirometry indices included Forced Vital Capacity (FVC), mid-expiratory-flow (FEF25-75) and tidal volume (VT). We calculated FEF25-75/FVC and VT/FVC ratios. Results: FVC declined from 67?±8 while walking to 19?±6% predicted values. FEF25-75 values that were elevated (116?±23% predicted) while walking, decreased to 69?±27% predicted at end-stage where 7 patients responded to bronchodilators. VT/FVC ratio was 0.25?±0.06 while walking, increased to 0.35 once on wheelchairs and further increased to 0.57?±0.19 at end-stage disease. FEF25-75/ FVC ratio was 2.54?±0.70 above normal (~1.0) increasing to 4.16?±0.75 at end stage. A sharp elevation was seen in FEF25-75/FVC ratio when FEV1 was still ~45 % predicted and 2-years prior to death. Conclusions: Having a low baseline-FVC (60% predicted) artificially raises FEF25-75 values, so FEF25-75 of â??mild obstructionâ? values may indicate severe airway obstruction in AT subjects. VT/FVC and FEF25-75/FVC ratios may therefore assist in revealing higher than normal breathing effort. The results further suggest adding VT/FVC and FEF25-75/FVC ratios to pulmonary function assessments in patients with AT.
Email: avi_vil@bezeqint.net