Seasonal onset of bronchiolitis obliterans syndrome in lung transplant recipients.
BACKGROUND
Bronchiolitis obliterans syndrome is the major complication in long-term survival of patients with lung transplants. Bronchiolitis obliterans syndrome is thought to represent a form of chronic allograft rejection and is associated with obstructive airways disease. Viral infections or other exogenous factors may trigger this condition.


METHODS
Because respiratory viral infections show seasonal clustering we studied seasonal onset of bronchiolitis obliterans syndrome in 157 lung and heart-lung transplant recipients. Individual baseline values of forced expiratory volume in 1 second were evaluated according to the International Society for Heart and Lung Transplantation criteria. For bronchiolitis obliterans syndrome classification, values of forced expiratory volume in 1 second were determined by the average of two measurements made at least 1 month apart. Onset of bronchiolitis obliterans syndrome was defined as the date of the initial pulmonary function test showing a persistent decline of forced expiratory volume in 1 second. Other factors causing obstructive airways disease were excluded.


RESULTS
Forty-nine patients (31%) showed development of bronchiolitis obliterans syndrome (n = 10 stage I, n = 13 stage II, n = 26 stage III) with onset of bronchiolitis obliterans syndrome 507 +/- 372 days (mean +/- standard deviation) after transplantation. Baseline value of forced expiratory volume in 1 second was reached at 270 +/- 231 days. Between January and March of each year onset of bronchiolitis obliterans syndrome developed in 23 patients (47%). In the second (April to June) and third (July to September) quarters a persistent decline of pulmonary function test results developed in 13 (27%) and 12 (24%) patients, respectively, whereas only 1 patient (2%) showed deterioration between October and December (p < 0.001).


CONCLUSIONS
Seasonal clustering of onset of bronchiolitis obliterans syndrome might thus indicate underlying unknown infectious triggers.
Hannover Medical School, Department of Respiratory Medicine, Germany.
J
J
Hohlfeld
J
J
Niedermeyer
H
H
Hamm
H J
HJ
Schäfers
T O
TO
Wagner
H
H
Fabel
D000328:Adult; D001989:Bronchiolitis Obliterans / Q000453:epidemiology* / Q000503:physiopathology; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D015994:Incidence; D016040:Lung Transplantation; D008297:Male; D008875:Middle Aged; D012621:Seasons; D013577:Syndrome