1.4000
#46-OR
IS CELL MEDIATED IMMUNITY UPREGULATED IN GASTROESOPHAGEAL REFLUX DISEASE-ASSOCIATED BRONCHIOLITIS OBLITERANS SYNDROME?
Angela D. Burnette, James Z. Appel, Karen M. Mohler, R. Duane Davis and Nancy L. Reinsmoen. Durham NC, USA, Duke University Medical Center, 27710, Pathology and Surgery.

---

Recipients (recips) of lung allografts experience the lowest graft survival rates and the highest chronic rejection (CR) rates of all solid organ recips. Bronchiolitis obliterans syndrome (BOS) is a surrogate marker for CR, diagnosed by decrements in the forced expiratory volume in 1 second. Gastroesophageal reflux disease (GERD) is frequently found in recips following lung transplantation (LTX) and has been linked with BOS. Fundoplication has been used to treat GERD diagnosed LTX recips, yielding significant improvements in lung function. Since the exact mechanisms of CR are poorly understood, we obtained whole blood (WB) from 22 LTX recips at varying times posttx. Utilizing recent technology, WB was stimulated with Phytohemagglutinin and the intracellular ATP (iATP) levels in CD4+ cells were measured as a surrogate marker for cell mediated immunity (CMI) (Cylex®, Inc). Average iATP levels tended to be higher in recips with GERD (n=7) when compared to recips without GERD (n=15 including those who had undergone fund [n=8]) (534 +/- 192 vs. 442 +/- 160, p = 0.36). Comparing recips with anti-HLA antibodies (Ab+ [n=8]) detected by flow cytometry, to Ab- recips (n=14): Ab+ recips had higher iATP levels than Ab- recips (577 +/- 170 vs. 411 +/- 130, p= 0.04). When Ab+ recips were excluded from analysis, iATP levels were higher in recips with BOS (n=7) vs. those without BOS (n=7) (492 +/- 164 vs. 331 +/- 58, p= 0.08). These results show an upregulation in CMI for recips with anti-HLA Ab, GERD, and/or BOS and suggest a cellular mechanism for GERD-associated BOS with a need for fundoplication in LTX recips diagnosed with GERD.