case_images: PMC10704095_01
case_images: Blood group antibody titers and immunosuppressive regimen used before and after transplantation. The recipient's ABO blood group was O and the donor's blood group was B, and the recipient's baseline anti-B antibody titers were 1:1,024 (anti-B IgM) and 1:64 (anti-B IgG), respectively. The recipient completed a pre-transplant desensitization protocol, whereafter anti-B antibody titers remained at low levels (equal or less than pre-transplant level 1:2) or declined to an undetectable level. Until POD 50, the recipient's anti-B IgM and anti-B IgG had increased to 1:64 and 1:32, respectively, and then gradually increased to untreated pre-transplant levels. The pink rectangle indicates tacrolimus (Tac) and mycophenolate mofetil (MMF). The yellow rectangle indicates the change of cyclosporine (CsA) and mizoribine (MZR) on POD49. The orange arrows indicate days of using rituximab. The purple arrows indicate days of using plasma exchange (PE). The grass green arrows indicate days of using double filtration plasmapheresis (DFPP). The dark green arrows indicate days and dose of using methylprednisolone (MP). The green rectangle indicates days and dose of using prednisone (Pred), staring at 50 mg/d and then prednisone tapered by 10 mg every other day to 10 mg/d for maintenance. The dark blue and light blue boxes indicate the dose and days of using anti-human T lymphocyte porcine immunoglobulin (p-ALG) and rabbit anti-human thymocyte immunoglobulin (ATG). The black dashed line indicates the day of transplantation.
case_images: fmed-10-1195419-g001.jpg
case_images: PMC10704095_01_fmed-10-1195419-g001.jpg
case_images: fig1
case_images: The baseline anti-B antibody titers of the recipient before transplantation were 1:1,024 (IgM) and 1:64 (IgG) (Figure 1). On the day of transplantation, the anti-B titers were reduced to 1:16 (IgM) and 1:2 (IgG) (Figure 1). To avoid injury caused by anti-B antibodies that trigger aAMR, the patient received 100 mg rituximab intravenously and four courses of PE or DFPP (Figure 1). Subsequently, the serum creatinine level increased to 697 mumol/L, and the anti-B antibody titers promptly increased (IgM, 1:1024; IgG, 1:256) (Figure 1).
case_images: Allograft biopsy specimen obtained on POD 18. (A) Immunohistochemical staining: C4d was diffusely positive (x200). (B) One micro-vein presented with venous endotheliitis, mild renal interstitial edema, patchy and diffuse infiltration of lymphocytes in the interstitium, patchy and mild renal tubulitis, and a few peritubular capillaritis; the interstitial matrix of renal tissue did not show hyperplasia and tubular atrophy; mild water degeneration of renal tubular epithelial cells and no necrosis of renal tubular epithelial cells (H.E, x400).
case_images: fmed-10-1195419-g002.jpg
case_images: PMC10704095_01_fmed-10-1195419-g002.jpg
case_images: fig2
case_images: T-cell-mediated rejection (aTCMR) (Banff 2019 grade IA, i1, t1, g0, v0, ci0, ct0, cg0, cv0, ptc1, g + ptc = 1, ah0, mm0, i-IFTA0, t-IFTA0, and diffusely positive C4d3) (Figure 2A), with only a few minor peritubular capillaritis (ptc1) in the allograft biopsy sample and no manifestation of glomerulonephritis (Figure 2B). The B19 DNA in paraffin-embedded kidney tissue was amplified by nested PCR, and the results were negative.
case_images: Hemoglobin levels before and after transplantation. After transplantation, the recipient's hemoglobin increased to 103 g/L at the highest level and then showed a progressive decrease in hemoglobin without obvious cause, which reached as low as 60 g/L on POD 19. After treatment, the recipient's hemoglobin (Hb) recovered and remained stable. The red arrows indicate days of using transfusion. The Green arrows indicate days of using recombinant human erythropoietin (EPO). The red squares indicate the results of HPV-B19 DNA and IgM testing, and the arrow points to the time of testing.
case_images: fmed-10-1195419-g003.jpg
case_images: PMC10704095_01_fmed-10-1195419-g003.jpg
case_images: fig3
case_images: Subsequently, hemoglobin levels gradually increased (Figure 3).
case_images: Clinical course of the patient. Graft function and fluctuation of immunosuppressant concentration before and after transplantation. The green square indicates the patient's first hospitalization and discharge with good recovery of graft function (with serum creatinine (SCr) rapidly declining to 200 mumol/L within 10 days post-transplantation). The blue square indicates that the patient was readmitted for treatment due to HPV-B19 infection and aTCMR, after which the patient improved following a series of treatments. The gray square indicates the patient's injury of graft function following a fierce anti-blood group antibody-mediated acute humoral rejection until the graft was lost and the patient was discharged again after resuming regular hemodialysis therapy.
case_images: fmed-10-1195419-g004.jpg
case_images: PMC10704095_01_fmed-10-1195419-g004.jpg
case_images: fig4
case_images: The TAC trough concentration was 7.4 ng/mL (Figure 4), and the anti-B titers decreased to 1:4 (IgM) and 1:2 (IgG).