Research ArticleTRANSPLANT

Mixed chimerism and acceptance of kidney transplants after immunosuppressive drug withdrawal

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Science Translational Medicine  29 Jan 2020:
Vol. 12, Issue 528, eaax8863
DOI: 10.1126/scitranslmed.aax8863
  • Fig. 1 Patient survival, graft survival, duration of complete withdrawal of IS drugs, and duration of chimerism in HLA-matched patients.

    (A) Patient survival. (B) Graft survival. (C) Duration off IS drugs. Patients without bars did not meet criteria to achieve IS drug withdrawal. (D) Duration of chimerism up to the last time point tested.

  • Fig. 2 Persistent mixed chimerism and kidney graft acceptance in HLA-matched recipients.

    The percentages of donor cells in whole blood, daily doses of CsA or tacrolimus, and serum creatinine concentrations (mg/dL) at serial time points after kidney transplantation are shown in 10 recipients who had at least 2% donor cells in all chimerism tests. Orange lines show whole blood chimerism, and blue lines show the daily dose of calcineurin inhibitor. MMF was discontinued in all patients at 1 month after transplant. Calcineurin inhibitor used in patient nos. 1 to 18 was CsA and was tacrolimus (Tac) in patient nos. 21 to 29.

  • Fig. 3 Differences in magnitude T and B cell chimerism are due to differences in kinetics of reconstitution of naïve cells in HLA-matched transplant recipients.

    (A) Mean percentages (±SEM) of donor-type cells among purified T cells, B cells, NK cells, CD34+ cells, granulocytes, and whole blood (WB) cells before and at serial time points after kidney transplantation (KTx) in all 29 patients. (B) Percentages in 10 patients with chimerism that persisted for at least 24 months. (C) Percentages in patients with chimerism that was lost within 24 months. The Wilcoxon signed-rank test was used to make statistical comparisons. (D) Mean percentages of naïve CD3+ T cells among PBMCs. (E) Percentages of naïve CD4+ T cells among PBMCs. (F) Percentages of naïve CD8+ T cells among PBMCs. (G) Percentages of thymic-derived CD3+ T cell precursors (cells containing TRECs) among PBMCs. (H) Percentages of thymic-derived CD4+ T precursors among PBMCs. (I) Percentages of thymic-derived CD8+ T precursors among PBMCs. (J) Percentages of B cell precursors (pro-B cells) among PBMCs. (K) Percentages of naïve B cells among PBMCs. The Mann-Whitney U test was used to make statistical comparisons. (L) compares the mean percentage of donor-type cells among sorted naïve B cells to mean percentages among sorted pro-B cells, naïve CD4+ T cells, memory RO+CD4+ T cells, naïve CD8+ T cells, and memory CD8+ T cells. There were 6 to 12 available patient samples analyzed at each time point for the naïve and precursor cell studies. The two-sided Dunnett’s test was used for multiple comparisons. ns, not significant (P > 0.05); *P < 0.05 and **P < 0.01.

  • Fig. 4 Differences in magnitude of T and B cell chimerism are due to differences kinetics of reconstitution of naïve cells in HLA haplotype–matched transplant recipients.

    (A) Mean percentages (±SE) of donor-type cells among T cells, B cells, NK cells, CD34+ cells, granulocytes, and whole blood cells before and at serial time points after kidney transplantation in all 22 patients. (B) Percentages in 10 patients with detectable chimerism for at least 12 months. (C) Percentages in patients in whom chimerism persisted for less than 12 months. The Wilcoxon signed-rank test was used to make statistical comparisons. (D) Mean percentages of naïve CD3+ T cells among PBMCs. (E) Percentages of naïve CD4+ T cells among PBMCs. (F) Percentages of naïve CD8+ T cells among PBMCs. (G) Mean Shannon index diversity scores of the TCRα chain genes. (H) Scores of the TCRβ chain genes. (I) Percentages of B cell precursors among PBMCs. (J) Percentages of naïve B cells among PBMCs. The Mann-Whitney U test was used to make statistical comparisons. (K) compares the mean percentage of donor-type cells among sorted naïve CD4+ T cells to memory RO+CD4+ T cells, naïve CD8+ T cells, and RO+ memory CD8+ T cells. There were 6 to 12 available patient samples analyzed at each time point for the naïve and precursor cell studies. The two-sided Dunnett’s test was used to make statistical comparisons of sorted cells. P > 0.05, *P < 0.05, **P < 0.01, and ***P < 0.001.

  • Fig. 5 Loss of mixed chimerism during or after the withdrawal of IS drugs in 10 HLA-mismatched patients.

    The percentage of donor cells in whole blood (red), daily doses of MMF (blue), trough blood concentrations of tacrolimus (green), and serum creatinine concentrations are shown at serial time points for each patient up to 762 days (24 months). Red and blue symbols are no longer shown after loss of chimerism or discontinuation of MMF, respectively. Arrows show acute rejection episodes (AR) or microvascular injury (MVI). Patient no. 9 died during tapering of tacrolimus. Due to pulmonary embolism (PE).

  • Table 1 HLA-matched patient characteristics, donor cells, and outcomes.

    ESRD, end-stage renal disease; FSGS, focal segmental glomerulosclerosis; IgA, IgA nephropathy; DM, diabetes; SLE, systemic lupus erythematosus; PKD, polycystic kidney disease; CIN, chronic interstitial nephritis.

    Patient no.Age at Tx/sexESRD diagnosisCD34+ cell dose
    (×106/kg)
    CD3+ cell dose
    (×106/kg)
    SCr: Last
    measure
    (mg/dl)
    Duration of
    follow-up
    (months)
    Duration off IS
    drugs (months)
    148/MUnknown811.3241*36
    239/FFSGS811.021570
    324/MDysplasia1311.621520
    452/MUnknown511.13137119
    534/MIgA1311.37135129
    661/FDM1211.301300
    723/FSLE17105.70‡,§119*12
    833/MReflux1710.75124122
    929/FUnknown1811.051210
    1052/FPKD1410.90120109
    1137/FIgA1412.40§11163
    1236/FPKD1011.20107101
    1326/MUnknown611.2010088
    1422/FUnknown1410.8610088
    1540/FIgA1011.139848||
    1642/MType 1 DM611.1334*23
    1730/MCIN615.77‡,§7152
    1839/MIgA911.298071
    1929/MIgA1211.267768
    2045/FUnknown1411.007259
    2162/FIgA1210.746860
    2254/FAlport411.006550
    2349/MDM611.035541
    2428/MReflux611.556338
    2537/MIgA711.304834
    2643/MUnknown1411.04460
    2738/FIgA610.803623
    2844/MIgA911.633522
    2930/MIgA1151.072714
    Median (months)8048

    *Deceased.

    †No loss of chimerism.

    ‡SCr, serum creatinine concentration just before dialysis.

    §Relapse of kidney disease without rejection.

    ||Acute rejection at four years off IS drug, returned to IS drug therapy. Duration of follow-up is to last SCr test. Patient nos. 7 and 29 were given 10 × 106 and 5 × 106 T cells/kg to increase chimerism levels. Patient nos. 1, 7, and 16 died in association with coronary artery disease, lupus-related stroke, and complications of morbid obesity and diabetes mellitus, respectively.

    • Table 2 HLA-haplotype–matched patient characteristics and outcomes.

      GN, glomerulonephritis; MN, membranous nephropathy; HTN, hypertensive nephropathy.

      Patient no.Age at Tx/
      sex
      ESRD
      diagnosis
      SCr: Last
      measure
      (mg/dl)
      Duration
      of
      follow-up
      (months)
      146/MIgA2.1696
      224/FSLE0.8479*
      335/FUnknown8.3676*
      433/MUnknown1.3875
      526/FSLE2.6167
      621/MUnknown1.3362
      747/FGN1.0658
      826/FMN1.5260
      955/MObstruction1.7015*,‡
      1034/MIgA6.40§54*
      1132/MMN1.2950
      1244/MUnknown1.1350
      1341/MUnknown0.7344
      1430/MUnknown1.5143*
      1550/FIgA0.9436*
      1627/FUnknown0.9132*
      1724/MUnknown1.5529*
      1831/MIgA1.1628*
      1952/FIgA0.8022
      2037/MIgA1.3918
      2159/FPKD1.2115
      2226/MHTN1.1914*
      Median47

      *Persistent chimerism during first year.

      †Chronic pyelonephritis, returned to dialysis.

      ‡Deceased.

      §Relapse of kidney disease, returned to dialysis. Patient no. 3 developed chronic pyelonephritis associated with chronic urinary tract infection without evidence of rejection on biopsy. Patient no. 10 developed glomerulonephritis without evidence of rejection on biopsy. Patient no. 5 had two rejection episodes after going off protocol to switch from MMF to azathioprine maintenance in anticipation of pregnancy. Biopsies showed acute and chronic rejection.

      • Table 3 HLA-haplotype–matched kidney transplant patients—Donor whole-blood chimerism.

        Shaded boxes show patients with persistent chimerism for at least 12 months.

        % Donor-type cells in WBNo. of HLA
        mismatches
        Patient no.CD3 (×106/kg)CD34
        (×106/kg)
        Day 60Day 90Day 180Day 270Day 360
        1312000003
        2101527433834191
        31022818111413
        4108000003
        5108300003
        6208000003
        72011300002
        85081882003
        9501081726255462
        10501170714129231
        11509000003
        125011000002
        135015000002
        1470104336241383
        15752247302928281
        16100242853554811
        174*2614212121163
        181002549425960442
        1910025000002
        2010017200003
        211001622170003
        22100173734121082

        *Dose limited by transfusion reaction

        Supplementary Materials

        • stm.sciencemag.org/cgi/content/full/12/528/eaax8863/DC1

          Fig. S1. Loss of mixed chimerism and kidney graft acceptance in HLA-matched recipients.

          Fig. S2. Changes in the mean percentages of total, naïve, and memory T cells before and at serial time points after transplantation in HLA-matched patients.

          Fig. S3. Changes in B cell subsets and absolute numbers of T and B cells in HLA-matched patients.

          Fig. S4. Changes in subsets of memory T cells among PBMCs in HLA-matched patients.

          Fig. S5. Changes in subsets of memory T cells among PBMCs in HLA haplotype–matched patients.

          Fig. S6. Changes in the absolute numbers of total and naïve T and B cells in HLA haplotype–matched patients.

          Fig. S7. Representative MLR in HLA haplotype–matched recipients.

          Table S1. HLA typing and mismatch of donor/recipient pairs enrolled in haplotype-matched protocol.

          Table S2. Surveillance biopsy findings in haplotype-matched patients with mixed chimerism.

          Data file S1. Primary data.

        • The PDF file includes:

          • Fig. S1. Loss of mixed chimerism and kidney graft acceptance in HLA-matched recipients.
          • Fig. S2. Changes in the mean percentages of total, naïve, and memory T cells before and at serial time points after transplantation in HLA-matched patients.
          • Fig. S3. Changes in B cell subsets and absolute numbers of T and B cells in HLA-matched patients.
          • Fig. S4. Changes in subsets of memory T cells among PBMCs in HLA-matched patients.
          • Fig. S5. Changes in subsets of memory T cells among PBMCs in HLA haplotype–matched patients.
          • Fig. S6. Changes in the absolute numbers of total and naïve T and B cells in HLA haplotype–matched patients.
          • Fig. S7. Representative MLR in HLA haplotype–matched recipients.
          • Table S1. HLA typing and mismatch of donor/recipient pairs enrolled in haplotype-matched protocol.
          • Table S2. Surveillance biopsy findings in haplotype-matched patients with mixed chimerism.

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          Other Supplementary Material for this manuscript includes the following:

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