Immune status assay (ISA): a noninvasive procedure for studying allograft rejection.
BACKGROUND
There is a need for a simple, sensitive, noninvasive technique for monitoring graft function. We report here on a simple assay called immune status assay (ISA) that determines the status of the graft by simply examining the activation status of blood T cells.


METHODS
Graft-derived fibroblasts were used as a source of alloantigens and the recipient blood as a source of allograft-specific peripheral blood lymphocytes (PBL). PBL were added to wells containing donor or third-party graft-derived fibroblasts in the presence or absence of interleukin-2 (IL-2). On day 4 [(3)H]thymidine incorporation was quantified after the cells were incubated for 3 days at 37 degrees C, in a 5% CO(2) water-jacketed incubator. The results were analyzed using the following equation: %IL2 - /IL2+ = ((mean[(3)H]thymidine uptake in the absence of IL - 2) / (mean [(3)H]thymidine uptake in the presence of IL - 2)) x 100.


RESULTS
The ISA score (%IL-2 - /IL-2+) correlated strongly with the outcome of the graft, as it had a sensitivity of 82% for detecting rejections (14/17), and a specificity of 81% (30/37) for detecting non-rejections. Notably, the ISA detected immune T cell activation in the blood of graft rejecting subjects, which were not detected by currently used techniques such as mixed lymphocytes reaction.


CONCLUSIONS
The ISA is a straightforward procedure that detects allograft rejection with high specificity and sensitivity.
Fernandez
Luis A
LA
Division of Transplantation, Department of Surgery, University of Wisconsin Medical School, 600 Highland Avenue, Madison, WI 53792-7375, USA.
Tsuchida
Masahiro
M
Manthei
Eric
E
Fechner
John H
JH
Oberley
Terry D
TD
Leverson
Glen E
GE
Knechtle
Stuart J
SJ
Hamawy
Majed M
MM
D000069594:Abatacept; D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D002455:Cell Division; D018920:Coculture Techniques; D003404:Creatinine / Q000097:blood; D016572:Cyclosporine / Q000494:pharmacology; D004261:DNA Replication; D004167:Diphtheria Toxin / Q000627:therapeutic use; D004359:Drug Therapy, Combination; D005347:Fibroblasts / Q000276:immunology; D006084:Graft Rejection / Q000175:diagnosis* / Q000276:immunology; D018796:Immunoconjugates / Q000627:therapeutic use; D007165:Immunosuppression Therapy / Q000379:methods; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D000922:Immunotoxins / Q000627:therapeutic use; D007376:Interleukin-2 / Q000494:pharmacology; D007519:Isoantigens / Q000276:immunology; D016030:Kidney Transplantation; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D008253:Macaca mulatta; D008775:Methylprednisolone / Q000627:therapeutic use; D011993:Recombinant Fusion Proteins / Q000627:therapeutic use; D012680:Sensitivity and Specificity; D020123:Sirolimus / Q000627:therapeutic use; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D014184:Transplantation, Homologous / Q000276:immunology*
D000911:Antibodies, Monoclonal; D004167:Diphtheria Toxin; C114317:FN18-CRM9; D018796:Immunoconjugates; D007166:Immunosuppressive Agents; D000922:Immunotoxins; D007376:Interleukin-2; D007519:Isoantigens; D011993:Recombinant Fusion Proteins; D000069594:Abatacept; D016572:Cyclosporine; D003404:Creatinine; D020123:Sirolimus; D008775:Methylprednisolone