Induction Type and Outcomes in HLA-DR Mismatch Kidney Transplantation.

BACKGROUND: In kidney transplantation, donor recipient human leukocyte antigen (HLA)-DR mismatch signals high immunologic risk and portends inferior outcomes. We compared the impacts of depleting vs non-depleting antibody induction on the outcomes in kidney transplant recipients (KTRs) at different levels of HLA-DR mismatches. METHODS: Using the Organ Procurement and Transplantation Network/United Network for Organ Sharing database, we identified adult KTRs from 2001 to 2015 who received induction therapy with either depleting (thymoglobulin/alemtuzumab) or non-depleting (basiliximab/daclizumab) antibody and were discharged on calcineurin inhibitor/mycophenolic acid maintenance. Patients were then stratified by the number of donor-recipient HLA-DR mismatches (0, 1, 2) in both living donor (LD) and deceased donor (DD) KTRs. Under each HLA-DR mismatch category, long-term outcomes were compared for depleting vs non-depleting induction using a Cox model. RESULTS: A total of 63,821 LD (HLA-DR mismatches: 0, n = 6945 [depleting = 4409, non-depleting = 2536]; 1, n = 19,557 [depleting = 13,558, non-depleting = 6019]; and 2, n = 10,727 [depleting = 7694, non-depleting = 3033]) and 64,922 DD (HLA-DR mismatches: 0, n = 13,915 [depleting = 10,124, non-depleting = 3791]; 1, n = 27,994 [depleting = 20,454, non-depleting = 7540]; and 2, n = 23,013 [depleting = 16,908, non-depleting = 6105]) KTRs were included in the analysis. Adjusted patient death risk was significantly lower in the depleting vs non-depleting antibody induction group among DD kidney recipients (hazard ratio 0.90, 95% CI 0.85-0.96, P = .001) and trended lower among LD kidney recipients (HR 0.88, 95% 0.79-1.01, P = .05) with 2 HLA-DR mismatches. DISCUSSION: Our study found a patient survival benefit associated with the use of perioperative induction with depleting when compared to non-depleting antibody in KTRs with 2 HLA-DR mismatches and maintained on a calcineurin inhibitor/mycophenolic acid regimen.

Prolonged Impairment of Immunological Memory After Anti-CD20 Treatment in Pediatric Idiopathic Nephrotic Syndrome.

Anti-CD20 therapy is effective in idiopathic nephrotic syndrome (INS). However, transient or sustained hypogammaglobulinemia predisposing to an increased risk of infectious diseases can follow treatment in some patients. We analyzed the long-term effects of anti-CD20 therapy on immunological memory in 27 frequently-relapsing/steroid-dependent INS pediatric patients after more than 4 years from the first and at least 2 years from the last anti-CD20 infusion. Twenty-one INS children, never treated with anti-CD20 and under an intense oral immunosuppression with prednisone, mycophenolate mofetil, and calcineurin inhibitors were also included as control group. Levels of circulating B-cell subpopulations, total serum immunoglobulins and IgG and memory B cells directed against hepatitis B virus (HBV) and tetanus were determined and correlated with clinical characteristics. Nine patients never relapsed after more than 2 years from the last anti-CD20 administration (5 after the first, 3 after the second, and 1 after the fifth infusion). At last follow-up, most patients showed a complete recovery and normalization of total (27/27), transitional (27/27), and mature-naïve B cells (25/27). However, a sustained and significant reduction of total memory (20/27) and switched memory (21/27) B cells was found in most patients. 11/27 patients showed hypogammaglobulinemia at last follow-up and, among these, four presented with a severe hypogammaglobulinemia (IgG < 160 mg/dl). In contrast, no patient in the control group developed a severe hypogammaglobulinemia. Age at the time of first anti-CD20 administration was positively associated with IgG levels at last follow-up (p = 0.008); accordingly, younger patients had an increased risk of hypogammaglobulinemia (p = 0.006). Furthermore, severe hypogammaglobulinemia and delayed switched memory B-cell reconstitution were more frequent in non-relapsing patients. Reduced IgG levels against HBV and tetanus were observed at baseline and further declined at last follow-up. Antigen-specific memory B-cells were induced by re-immunization, but specific IgG titers remained low. In conclusion, anti-CD20 therapy can be disease-modifying in some INS patients. However, a prolonged impairment of immunological memory occurs frequently, independently from the number of anti-CD20 infusions, particularly in younger patients. Re-immunization may be necessary in these patients.

Tacrolimus for the prevention and treatment of rejection of solid organ transplants.

Since its introduction to the antirejection armamentarium in 1994, tacrolimus has become the workhorse of transplant professionals for avoidance of solid organ transplant rejection. Not only does tacrolimus have potent immunosuppressive qualities that prevent rejection, but dosing is straight forward and it is generally well tolerated. However, in the long term, conditions such as calcineurin inhibitor nephrotoxicity can become a problem. A discussion of the compound, the pharmacokinetics, history, and current approved uses for tacrolimus is described. Indeed, tacrolimus is the most important drug for preventing transplant rejection. However, the increased appreciation for significant side effects, particularly in the long term, has led to building interest in new agents with different mechanisms of action and different metabolism.