Induction immunosuppressive therapy in renal transplantation: does basiliximab make the difference?

The effect of induction immunosuppression for kidney transplant on the latent HIV reservoir

The HIV latent viral reservoir (LVR) remains a major challenge in the effort to find a cure for HIV. There is interest in lymphocyte-depleting agents, used in solid organ and bone marrow transplantation to reduce the LVR. This study evaluated the LVR and T cell receptor repertoire in HIV-infected kidney transplant recipients using intact proviral DNA assay and T cell receptor sequencing in patients receiving lymphocyte-depleting or lymphocyte-nondepleting immunosuppression induction therapy. CD4+ T cells and intact and defective provirus frequencies decreased following lymphocyte-depleting induction therapy but rebounded to near baseline levels within 1 year after induction. In contrast, these biomarkers were relatively stable over time in the lymphocyte-nondepleting group. The lymphocyte-depleting group had early TCRβ repertoire turnover and newly detected and expanded clones compared with the lymphocyte-nondepleting group. No differences were observed in TCRβ clonality and repertoire richness between groups. These findings suggest that, even with significant decreases in the overall size of the circulating LVR, the reservoir can be reconstituted in a relatively short period of time. These results, while from a relatively unique population, suggest that curative strategies aimed at depleting the HIV LVR will need to achieve specific and durable levels of HIV-infected T cell depletion.

Early Changes in Kidney Transplant Immunosuppression Regimens During the COVID-19 Pandemic

BACKGROUND

Kidney transplant recipients have higher risk of infectious diseases due to their reliance on immunosuppression. During the current COVID-19 pandemic, some clinicians might have opted for less potent immunosuppressive agents to counterbalance the novel infectious risk. We conducted a nationwide study to characterize immunosuppression use and subsequent clinical outcomes during the first 5 months of COVID-19 pandemic in the United States.

METHODS

Using data from the Scientific Registry of Transplant Recipients, we studied all kidney-only recipients in the United States from January 1, 2017, to March 12, 2020 ("prepandemic" era; n = 64 849) and from March 13, 2020, to July 31, 2020 ("pandemic" era; n = 5035). We compared the use of lymphocyte-depleting agents (versus basiliximab or no induction) and maintenance steroids (versus steroid avoidance/withdrawal) in the pandemic era compared with the prepandemic era. Then, we compared early posttransplant outcomes by immunosuppression regimen during the pandemic era.

RESULTS

Recipients in the pandemic era were substantially less likely to receive lymphocyte-depleting induction agents compared with their prepandemic counterparts (aOR = 0.400.530.69); similar trends were found across subgroups of state-level COVID-19 incidence, donor type, and recipient age. However, lymphocyte-depleting induction agents were associated with decreased rejection during admission (aOR = 0.110.230.47) but not with increased mortality in the pandemic era (aHR = 0.130.471.66). On the other hand, the use of maintenance steroids versus early steroid withdrawal remained similar (aOR = 0.711.071.62).

CONCLUSIONS

The use of lymphocyte-depleting induction agents has decreased in favor of basiliximab and no induction during the COVID-19 pandemic. However, this shift might have resulted in increases in rejection with no clear reductions in posttransplant mortality.

Induction Therapy With ATG Compared With Anti-IL2 Basiliximab in Low-Immunologic Risk Kidney Transplant Recipients

Practically all kidney allograft recipients require immunosuppressive therapy to prevent rejection and loss of the allograft. The aim of this study was to determine the occurrence of biopsy-proven acute rejection in low-immunologic risk kidney transplant recipients according to the type of induction (basiliximab vs low-dose of rabbit antithymocyte globulin [rATG], 3.5 mg/kg).

MATERIALS AND METHODS

A total of 125 patients after primary kidney transplant were included in the retrospective analysis with 6-month follow-up. The immunosuppression regimen included tacrolimus, mycophenolic acid, and corticoids.

RESULTS

We did not find any significant difference in the occurrence of acute rejection or difference in the occurrence of infection complications. Patients in the rATG group had a significantly longer period of cold ischemia, more frequently received kidney transplants from expanded criteria donors, and had significantly more mismatches in HLA-DR. Delayed graft function (DGF) was identified as an independent risk factor for biopsy-proven acute rejection (hazard ratio, 3.4859; P = .003). There was comparable incidence of DGF between the 2 groups despite that there were several factors that are more commonly associated with DGF in the rATG group.

CONCLUSION

Patients with low immunologic risk and high risk of DGF benefit from the rATG induction in dose of 3.5 mg/kg without the increased risk of infection complications with the assumption of good graft function in long-term post-transplant period.

Basiliximab induction in kidney transplantation with donation after cardiac death donors

Basiliximab is a monoclonal antibody that binds to the α-chain of the interleukin (IL)-2 receptor. It is used as induction therapy in kidney transplantation. The objective of the present study was to evaluate induction therapy with single-dose basiliximab (Simulect^®) in kidney transplantation with donation after cardiac death (DCD) donors. A total of 33 DCD kidney transplants were performed between December 2010 and July 2013 in patients who received single-dose basiliximab (20 mg) as induction therapy. The maintenance immunosuppression included calcineurin inhibitor (cyclosporine A or tacrolimus), mycophenolate mofetil and corticosteroids. The follow-up time was 1 year. The mean ages of the DCD donors and recipients were 29.3 and 41.1 years, respectively. Within the 1-year follow-up, the overall incidence of acute rejection was 9.1%. There were 10 cases of delayed graft function among the recipients. Mean serum creatinine values at 1 week and at 1, 3, 6, 9 and 12 months post-transplantation were 257.6, 238.2, 194.5, 159.3, 137.9 and 110.8 µmol/l, respectively, with a favorable trend to allograft function recovery over time. The 1-year patient and graft survival rates were 96.9 and 90.9%, respectively, with an infection rate of 24.2%. Increased alanine aminotransferase/aspartate transaminase levels in only 2 patients were considered to be associated with basiliximab. This experience with single-dose basiliximab for induction therapy in DCD kidney transplantation showed that favorable clinical outcomes were achieved in terms of graft survival and function within 1 year.

Basiliximab induction in patients receiving tacrolimus-based immunosuppressive regimens

PURPOSE

The use of basiliximab induction increased significantly in recent years based on its superior efficacy and excellent safety profile demonstrated in studies with cyclosporine-based immunosuppression. However, its clinical utility in patients receiving tacrolimus-based immunosuppressive regimens is still uncertain.

METHODS

We retrospectively reviewed data of 366 low immunological risk recipients of deceased donor kidney transplants. Of them, 134 received basiliximab and tacrolimus (TAC-IL2-RA), 100 received basiliximab and delayed tacrolimus(dTAC-IL2-RA), and 132 patients received tacrolimus without basiliximab(TAC-No). The endpoints were the incidence of acute rejection, graft function, and patient and graft survivals at 1 year.

RESULTS

The incidence of acute rejection was higher in dTAC-IL2-RA compared to TAC-IL-2RA and TAC-No Groups (33 vs.14.9 vs. 14.3 %, p < 0.001). Inferior creatinine clearance was observed in dTAC-IL2-RA Group compared to TAC-IL2-RA and TAC-No Groups at months 1 (41.6 vs. 49.9 vs. 44.8 mL/min, p = 0.004), 3 (49.8 vs. 57.2 vs. 53.5 mL/min, p = 0.017), and 6 (53.1 vs. 61.8 vs. 57.0 mL/min, p = 0.001). Patients who received basiliximab (TAC-IL2-RA and dTAC-IL2-RA Groups) had lower incidence of posttransplant diabetes (24 vs.18 vs. 39.3 %, p = 0.009). Patient and graft survivals were similar among the groups.

CONCLUSIONS

In low immunological risk kidney transplant recipients receiving tacrolimus, the use of basiliximab induction was not associated with lower rejection rates and did not allow delayed tacrolimus introduction.

Infectious complications associated with monoclonal antibodies and related small molecules

Biologics are increasingly becoming part of routine disease management. As more agents are developed, the challenge of keeping track of indications and side effects is growing. While biologics represent a milestone in targeted and specific therapy, they are not without drawbacks, and the judicious use of these "magic bullets" is essential if their full potential is to be realized. Infectious complications in particular are not an uncommon side effect of therapy, whether as a direct consequence of the agent or because of the underlying disease process. With this in mind, we have reviewed and summarized the risks of infection and the infectious disease-related complications for all FDA-approved monoclonal antibodies and some related small molecules, and we discuss the probable mechanisms involved in immunosuppression as well as recommendations for prophylaxis and treatment of specific disease entities.