Clinical Relevance of Low Levels of Preformed Alloantibodies Detected by Flow Cytometry in the First Year Post–Kidney Transplantation

• Published in: Transplantation proceedings Vol. 37; no. 6; pp. 2750 - 2752
• Main Authors: Michelon, T., Schroeder, R., Fagundes, I., Canabarro, R., Sporleder, H., Rodrigues, H., Silveira, J., Montagner, J., Garcia, V., Neumann, J., Graudenz, M.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY Elsevier Inc 01.07.2005; Elsevier Science
• Subjects: Biological and medical sciences; Cadaver; Cytotoxicity, Immunologic; False Negative Reactions; Flow Cytometry; Follow-Up Studies; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Graft Rejection - epidemiology; Graft Survival - immunology; Histocompatibility Antigens Class I - immunology; HLA-D Antigens - immunology; Humans; Isoantibodies - blood; Kidney Transplantation - immunology; Kidney Transplantation - mortality; Medical sciences; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Surgery of the urinary system; Survival Analysis; Tissue Donors; Tissue, organ and graft immunology; Treatment Outcome; Medicine; Relevance; Flow cytometry; Treatment; Urinary system; Low; Surgery; Alloantibody; Graft; Homotransplantation; Kidney; Kidney transplantation
• DOI: 10.1016/j.transproceed.2005.05.040
• ISSN: 0041-1345

To determine the prevalence of transplants performed with a false-negative cytotoxicity cross-match and to analyze the clinical relevance of alloantibodies (Ab) detected only by flow cytometry (flow). We studied 66 patients undergoing kidney transplantation from a cadaveric donor. All patients had a simultaneous negative T+AHG+DTT and B+DTT. Pretransplant sera were retrospectively analyzed by flow cytometry according to an Emory University protocol: (1) T+ and B−: Ab anti-class I; (2) T− and B+: anti-class II; (3) T+B+: anti-class I + II. Chi-square, Fisher exact, Student t test, and Kaplan Meier analyses were employed with significance assigned at P ≤ .05. The overall incidence of false-negative cytotoxicity was 33.3% (22/66), namely, 6.1% ( n = 4) anti-class I; 9.1% ( n = 6) anti-class II; and 18.2% ( n = 12) anti-class I + II. Primary nonfunctioning grafts occurred in 6.8% (3/44) and 13.6% (3/22) negative and positive flow patients (two anti-class I + II and one class II; P = .39). The incidence of graft loss in the first year was respectively, 13.6% (6/44) and 18.2% (4/22; two anti-class II and two anti-class I + II; P = .72). Compared to flow-negative grafts, creatinine levels were significantly higher among flow-positive patients at 8 and 12 weeks. One-year graft survivals were 86.4% among negative versus 81.8% for the positive group ( P = .67). We observed that 33% of kidney transplant recipients had low levels of alloantibodies detected only by flow. This single factor was associated with the worst graft function in the first trimester with a suggestion of a higher risk for non-functioning graft.