EARLY BIOCHEMICAL INDICATORS OF THE OBLITERATIVE BRONCHIOLITIS SYNDROME IN LUNG TRANSPLANTATION

The diagnosis of the obliterative bronchiolitis syndrome in lung trans plantation is presently best established by evaluation of postoperativ e lung function tests. Unfortunately the decline in lung function occu rs only when obliteration has progressed significantly and is therefor e not an early predictive indicator. To distinguish patients at increa sed risk for the development of obliterative bronchiolitis, we regular ly assessed the chemiluminescence response of polymorphonuclear leukoc ytes, opsonic capacity, and plasma elastase/beta-N-acetylglucosaminida se in 52 outpatients (25 women and 27 men; mean age 45 +/- 12 years) w ho underwent transplantation between January 1991 and January 1992. Re cent onset bronchiolitis within the described observation period occur red in 16 patients (group obliterative bronchiolitis). A matched cohor t of 16 patients was formed according to type of procedure, age and fo llow-up (control) from the remaining 36 patients. Data obtained from a period 6 months before clinical onset of the syndrome showed a signif icant drop of the opsonic capacity (group obliterative bronchiolitis = 87% +/- 7%; control = 100% +/- 9%; p < 0.023) and rise of the N-acety l-D-glucosaminidase (group obliterative bronchiolitis = 7.5 +/- 2 U/L; control = 5.8 +/- 1.8 U/L; p < 0.04). No correlation was found betwee n the number of infectious events or rejection episodes and the incide nce of obliterative bronchiolitis. According to these results, it can be concluded that a decrease in the plasma opsonic capacity and a rise in beta-N-acetylglucosaminidase may be early markers before clinical onset of obliterative bronchiolitis. The nonspecific immune system may therefore play an important role in the development of obliterative b ronchiolitis.