Differential soluble interleukin-2R levels in bilateral bronchoalveolar lavage after single lung transplantation

Preliminary reports suggest that measurement of the soluble 55 kd subunit of the interleukin-2 receptor may facilitate the diagnosis of allograft rejection in solid organ transplants. Levels of soluble interleukin-2 receptor in serum or plasma have previously lacked sufficient sensitivity and specificity for the diagnosis of acute allograft rejection. Because single lung transplantation is preferentially performed for nonseptic end-stage pulmonary and cardiopulmonary maladies, we questioned whether the pattern of soluble interleukin-2 receptor recovery in bronchoalveolar lavage fluid obtained from both the native and transplanted lungs may enhance correct diagnosis. Fifty-three consecutive fiberoptic bronchoscopic procedures were performed with bilateral bronchoalveolar lavage fluid. Transbronchoscopic biopsies were histologically classified by the International Society for Heart Transplantation Working Formulation for Standardized Nomenclature. "Soluble interleukin-2 receptor index" was calculated as the quotient of soluble interleukin-2 receptor (in units per milliliter) by enzyme-linked immunosorbent assay, divided by protein (in milligrams per milliliter) to correct for differences in bronchoalveolar lavage fluid techniques and cellularity. Soluble interleukin-2 receptor indexes were significantly increased in the allograft bronchoalveolar lavage fluid during histologic grade A (acute rejection) versus normal transbronchoscopic biopsy specimens (3395 +/- 1298 U/mg versus 76 +/- 21 U/mg) associated with an increased transplanted/native lung ratio (69.9 +/- 46 versus 2 +/- 1 [mean +/- standard error of the mean]) (one-way analysis of variance, p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)