EVALUATING T CELL ACTIVATION USING INTRACELLULAR ATP PRODUCTION IN LUNG RECIPIENTS.

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EVALUATING T CELL ACTIVATION USING INTRACELLULAR ATP PRODUCTION IN LUNG RECIPIENTS.
Angela D. Burnette, B.S. , Karen Mohler B.S.,MT and Nancy L. Reinsmoen, Ph.D. . Durham NC, Duke University Medical Center, 27710, Pathology .

Immune parameters that predict long-term graft outcome and allow for individualization of immunosuppression are very important. In an effort to better define these parameters, a whole blood assay was developed to measure increases in iATP synthesis by CD4+ cells in response to stimulation with a mitogen Phytohemagglutinin (PHA) (ImmuKnow™, Cylex Inc.®) which yields a rapid assessment of the early events in T cell activation without the requirement of long-term culture. We have applied this assay to test previously frozen peripheral blood lymphocytes (PBLs). Our goal was to measure the iATP levels (ng/ml) generated subsequent to PHA stimulation of PBLs from lung (LNG) recips procured pretransplant (pretx) to determine if these levels correlated with clinical events such as acute rejection (AR - diagnosed by transbronchial biopsy using ISHLT criteria). Briefly, frozen PBLs were thawed and cultured overnight with PHA. The CD4+ cells were magnetically selected and lysed. The light produced by luciferin and luciferase in the presence of the released iATP was measured in a luminometer and converted to ng/ml. We tested cells obtained pretx from 34 LNG recips with or without AR (Table). The results fell into two distinct groupings, High (>300 ATP ng/ml) and Low (<300 ATP ng/ml). The High group represented 33% (8/24) of recips that developed AR grade 2 or higher within 6mo posttx. The Low group included 20% (2/10) of recips who developed AR grade 2 or higher within 6mo. The negative predictive value was 80% for predicting those at low risk for developing AR. These preliminary results suggest that LNG recips who develop AR will do so within 6mo posttx. In addition, LNG recips with pretx values >300 ATP ng/ml are at increased risk for developing AR.

No.Pts. AR No AR
HIGH 24 8 16
LOW 10 2 8
TOTAL 34 10 24

	No.Pts.	AR	No AR
HIGH	24	8	16
LOW	10	2	8
TOTAL	34	10	24