Estimation of Sensitization Status in Renal Transplant Recipients by Assessing Indirect Pathway CD4 + T Cell Response to Donor Cell-pulsed Dendritic Cell.

BACKGROUND: Generation of donor-specific human leukocyte antigen antibody (DSA) via indirect allorecognition is detrimental to long-term survival of transplant organs. The detection of such immune responses would make it possible to define patients with high risk of sensitization. In this study, we established a novel method for evaluating indirect allorecognition to assess sensitization in kidney transplant recipients. METHODS: Recipient CD14 + monocytes were mixed with donor peripheral blood mononuclear cells; cultured in the presence of IL-4, GM-CSF, IL-1ß, and TNFα; and used as pulsed dendritic cells (DCs). Cell proliferation and cytokine production were evaluated by carboxyfluorescein diacetate succinimidyl ester-based T cell proliferation assay and Enzyme-Linked ImmunoSpot assay, respectively. RESULTS: CD4 + T cell proliferation was strongly observed in following coculture with allogeneic antigen-pulsed DC leading to interferon-γ and IL-21 production. About 1% of CD4 + T cells exhibited Tfh-like phenotype (PD-1 high CXCR5 + ICOS + CD40L + ). Recipient DC pulsed with donor peripheral blood mononuclear cells was cocultured with recipient CD45RA+CD4+ and CD45RA-CD4+ (generally defined as naive and memory in humans, respectively) T cells. Irrespective of preformed or de novo DSA status, CD45RA + CD4 + T cells constantly produced IL-21. In contrast, IL-21-produced CD45RA - CD4 + T cells were significantly higher in preformed DSA-positive patients than those in negative patients (80.8 ± 51.2 versus 14.8 ± 20.4, P < 0.001). In de novo DSA-positive patients, IL-21-produced CD45RA - CD4 + T cells were significantly increased after transplantation compared with before transplantation (9.23 ± 9.08 versus 43.9 ± 29.1, P < 0.001). CONCLUSIONS: Assessment of indirect pathway CD4 + T cell response could provide new insights into the underlying mechanism of de novo DSA production, leading to the development of effective strategies against antibody-mediated rejection.

A case of acute rejection with adenovirus infection after ABO-incompatible kidney transplantation.

We report clinical and histopathologic findings of a case of acute rejection with adenovirus infection after kidney transplantation. A 63-yr-old woman with end-stage renal disease caused by lupus nephritis received an ABO-incompatible living kidney transplantation from her husband. On the 7th post-operative day (POD), she had fever, hematuria, and bladder irritation. Although she was treated with an antibiotic, the symptoms were not improved. We diagnosed adenovirus infection as positive with the urine shell vial method and blood PCR analysis. Cyclophosphamide was interrupted and immunoglobulin therapy was performed. However, urine output decreased and serum creatinine levels increased. An episode biopsy was performed on POD 20. We diagnosed acute antibody-mediated rejection. She was treated with plasma exchange for acute rejection and antiviral drug (rivabirin) for active adenovirus infection. However, the renal graft dysfunction was deemed irreversible and the renal graft was removed on POD 34. The graftectomy specimen showed acute rejection and acute tubular necrosis with adenovirus infection.