Late-onset neutropenia and acute rejection in ABO-incompatible kidney transplant recipients receiving rituximab and mycophenolate mofetil

Analysis of death avoidance by concomitant use of prednisone in patients with renal transplant using the Food and Drug Administration Adverse Event Reporting System

BACKGROUND

Patients with renal transplant are frequently administered immunosuppressants to prevent transplant-related adverse events. There are mainly nine immunosuppressants on the market, and multiple immunosuppressants are frequently administered for patients with renal transplant. Identifying which immunosuppressant was responsible when efficacy or safety was observed in patients taking multiple immunosuppressants is difficult. This study aimed to identify the immunosuppressant that was effective in reducing death in patients with renal transplant. A very large sample size was required to conduct prospective clinical trials of immunosuppressant combinations, which is impractical. We investigated cases wherein death occurred despite immunosuppressant administration in patients with renal transplant using Food and Drug Administration Adverse Event Reporting System (FAERS) data.

MATERIAL AND METHOD

We used FAERS data reported between January 2004 and December 2022 in patients with renal transplant who received one or more immunosuppressants. Groups were defined for each combination of immunosuppressants. Comparison between two identical groups except for the presence or absence of prednisone was performed using the reporting odds ratio (ROR) and the adjusted ROR (aROR) controlling for differences in patient background.

RESULTS

When the group without prednisone was set as the reference, the aROR for death was significantly <1.000 in several cases in the group to which prednisone was added.

CONCLUSIONS

The inclusion of prednisone in the immunosuppressant combinations was suggested to be effective in reducing death. We provided the sample code of software R that can reproduce the results.

Burden of neutropenia and leukopenia among adult kidney transplant recipients: A systematic literature review of observational studies

BACKGROUND

Leukopenia and neutropenia (L/N) may affect treatment decisions, potentially resulting in poor clinical and economic outcomes among kidney transplant recipients (KTRs). The burden of L/N is poorly quantified systematically. This systematic literature review aimed to summarize the incidence of, risk factors for, and clinical and economic outcomes associated with L/N post-KT.

METHODS

We systematically searched MEDLINE, Embase, and the Cochrane Library (from database inception-June 14, 2021) and conferences (past 3 years) to identify observational studies examining epidemiology, risk factors, or outcomes associated with L/N among adult KTRs.

RESULTS

Of 2081 records, 82 studies met inclusion criteria. Seventy-three studies reported the epidemiology of L/N post-KT. Pooled incidence of neutropenia, defined as absolute neutrophil counts (ANC) <1000/μl, ranged from 13% to 48% within 1-year post-transplant; ANC <500/μl ranged from 15% to 20%. Leukopenia, defined as white blood cell counts <3500/μl, was 19% to 83%. Eleven studies reported independent risk factors associated with L/N post-KT. D+/R- cytomegalovirus status, mycophenolic acid (MPA), and tacrolimus use were the most consistent risk factors across studies. Fourteen studies reported L/N-associated clinical outcomes. We noted a trend toward a positive association between neutropenia and acute rejection/opportunistic infections. Mixed findings were noted on the association between L/N and graft failure or mortality. Dosage modifications of valganciclovir, MPA, cotrimoxazole, and anti-thymoglobulin and the need for granulocyte colony-stimulating factor (G-CSF) use were common with L/N.

CONCLUSION

Findings suggest post-transplant L/N were common and associated with frequent modifications of immunosuppressive agents, requiring G-CSF use, and rejection or opportunistic infections. Findings highlight the need for interventions to reduce risk of L/N post-KT.

Neutropenia in pediatric solid organ transplant

Neutropenia is generally defined as an absolute neutrophil count in the circulation of less than 1500/mm³ and occurs in up to 25%-30% of pediatric solid organ transplant recipients (SOT) within the first year after transplantation. In the SOT population, neutropenia is most often a result of drug-induced bone marrow suppression but can also be secondary to viral infection, nutritional deficiencies, lymphoproliferative infiltrate, and inherited causes. Outcomes for patients with neutropenia vary by degree of neutropenia and type of solid organ transplant. Management of neutropenia should begin by addressing the underlying cause, including reducing or removing medications when appropriate, treating infections, and addressing nutrient deficiencies; however, consultation with an experienced pediatric hematologist and use of granulocyte colony-stimulating factor (G-CSF) may be helpful in some cases. Overall, data on clinical outcomes for G-CSF use remain limited, but observational studies may support its use in patients with infections or severe neutropenia.

Outcomes among CMV-mismatched and highly sensitized kidney transplants recipients who develop neutropenia

Limited data exist on the incidence and clinical outcomes of neutropenia among kidney transplant recipients. Our study included 572 adults who received a kidney transplant at the University of California, San Francisco Medical Center between 2012 and 2018, and were CMV-mismatched or had a PRA ≥ 80%. Recipients with HIV, Hepatitis B and C, and primary non-function were excluded. Participants were followed for at least one year after transplantation. Neutropenia was defined as absolute neutrophil count < 1000 cells/μL. Cox proportional hazards regression models using neutropenia as a time-varying predictor were used to determine the risk of mycophenolic acid and valganciclovir changes, rejection, hospitalizations and use of granulocyte colony stimulating factor. Models were adjusted for demographics and transplant characteristics. Mean follow-up was 3.7 (SD, 1.8) years. The mean age of the cohort was 50.4 (13.1) years, and 57.5% were female. A total of 208 (36.3%) participants had neutropenia. Neutropenia was associated with an increased risk of valganciclovir or MPA dose reductions or discontinuations [adjusted hazard ratio, aHR: 7.78, 95% CI: 4.73- 12.81], rejection [aHR 2.00, 95% CI: 1.10-3.64] and hospitalizations [aHR 3.32, 95% CI: 2.12-5.19]. Neutropenia occurs frequently after kidney transplantation and leads to more medication changes and adverse clinical outcomes. This article is protected by copyright. All rights reserved.

Risk Factors and Management of Leukopenia After Kidney Transplantation: A Single-Center Experience

BACKGROUND

Leukopenia is a common complication after kidney transplantation. The etiology is multifactorial, with medication adverse effects and cytomegalovirus infection as main causes. Optimal strategies to prevent or treat posttransplant leukopenia remain unknown. We aimed to identify risk factors for leukopenia and to investigate the benefit of switching the immunosuppressive therapy to hydrocortisone as a continuous infusion.

METHODS

We retrospectively evaluated all patients with leukopenia after kidney transplantation between 2007 and 2017 at our center relative to age- and sex-matched controls.

RESULTS

Leukopenia was associated with the degree of rejection therapy before leukopenia, the immunosuppressive therapy before transplantation, and an induction therapy with rabbit antithymocyte globulin. Patients with leukopenia exhibited increased mortality, an increased incidence of bacterial and viral infections, and more acute rejections. Switching to hydrocortisone as a continuous infusion in patients with severe leukopenia decreased the duration of leukopenia and the incidence of subsequent viral infections, especially with cytomegalovirus.

CONCLUSION

Leukopenia is a risk factor for infectious complications and mortality, and it is associated with acute rejection. Switching immunosuppressive therapy to hydrocortisone as a continuous infusion is a safe approach to reduce the duration of leukopenia and the incidence of viral infections.

Long-Term Outcome of ABO-Incompatible Kidney Transplantation in Patients Treated With Low-Dose Rituximab Regimen

BACKGROUND

Introduction of rituximab in the desensitization protocols for ABO-incompatible (ABOI) kidney transplantation (KTX) has afforded excellent results. However, the acceptability of minimal dosage of rituximab in these protocols remains to be defined.

METHODS

Sixty-three patients who underwent ABOI KTX were included in this study. The desensitization protocol consisted of plasmapheresis, tacrolimus, mycophenolate mofetil, methylprednisolone, intravenous immunoglobulin, basiliximab, and low-dose rituximab (100 mg/body). We evaluated the efficacy, safety, and long-term outcome of this protocol (group R, n = 39) and compared them with those of patients who underwent splenectomy (group S, n = 24).

RESULTS

Graft and patient survival at 10 years after KTX were comparable between the groups (94.4% [group R] vs 95.4% [group S] and 94.6% [group R] vs 95.8% [group S], respectively). The incidence of acute antibody-mediated rejection (AAMR) was similar in the 2 groups (10.2% vs 12.5%). There were no significant differences in the incidence of chronic active antibody-mediated rejection. Of the patients, 7 developed AAMR and 3 of these patients (1 in group R and 2 in group S) lost their grafts. There were no significant differences in the incidence of chronic active antibody-mediated rejection. The incidence of postoperative cytomegalovirus infection in group R was significantly lower than that in group S. Furthermore, the incidence of postoperative late-onset neutropenia was low in group R.

CONCLUSIONS

A low-dose rituximab regimen for ABOI KTX is acceptable for preventing AAMR with a low incidence of delayed adverse events.

Current protocols and outcomes of ABO-incompatible kidney transplantation

One of the principal obstacles in transplantation from living donors is that approximately 30% are immunologically incompatible because of the presence in the recipient of antibodies directed against the human leukocyte antigen system of the donor or because of the incompatibility of the ABO system. The aim of this review is to describe the more recent data from the literature on the different protocols used and the clinical outcomes of ABO-incompatible kidney transplantation. Two different strategies are used to overcome these barriers: desensitization of the recipient to remove the antibodies and to prevent their rebound after transplantation and the exchange of organs between two or more pairs. The largest part of this review is dedicated to describing the techniques of desensitization. Even if the first reports of successful renal transplantation between ABO-incompatible pairs have been published by 1980, the number of ABO-incompatible transplants increased substantially in this century because of our improved knowledge of the immune system and the availability of new drugs. Rituximab has substantially replaced splenectomy. The technique of apheresis has improved and more recently a tailored desensitization proved to be the more efficient strategy avoiding an excess of immunosuppression with the related side effects. Recent reports document outcomes for such transplantation similar to the outcomes of standard transplantation.

Latest insights on ABO-incompatible living-donor renal transplantation

This review summarizes the latest insights on ABO‐incompatible living‐donor renal transplantation. Desensitization protocols and clinical outcomes were investigated, and a comparison was made with kidney‐paired donation, which is not permitted in Japan for ethical reasons. Although renal transplantation is greatly beneficial for most patients with end‐stage kidney disease, many of these patients must remain on dialysis therapy for extended periods due to the scarcity of organs from deceased donors. ABO blood type incompatibility was once believed to be a contraindication to renal transplantation due to the increased risk for antibody‐mediated rejection and early graft loss attributable to isoagglutinins. Recently, pretransplant desensitization strategies, such as removal of isoagglutinins and antibody‐producing cells, have achieved successful outcomes, although it remains unclear whether graft survival and patient morbidity are equivalent to those for ABO‐compatible renal transplantation. The present review suggested that ABO‐incompatible living‐donor renal transplantation might be a favorable radical renal replacement therapy for patients with end‐stage kidney disease.

Late-Onset Neutropenia after Rituximab Treatment for Adult-Onset Nephrotic Syndrome

A 41-year-old woman developed nephrotic syndrome at the age of 32 and was diagnosed with minimal change nephrotic syndrome based on a renal biopsy. Although remission was achieved with administration of prednisolone (PSL) and cyclosporine, the nephrotic syndrome recurred. She was also started on rituximab (RTX). She developed late-onset neutropenia after RTX treatment (R-LON) and improved 17 days later. Although the majority of R-LON cases undergo spontaneous remission, cases of death have been reported. This report is intended to warn about R-LON, since the use of RTX for adult-onset nephrotic syndrome is expected to increase in the future.

Efficacy of 2 Doses of Rituximab on B-Cell and Antidonor Antibody and Outcomes of ABO-Incompatible Living-Donor Pediatric Kidney Transplant

OBJECTIVES

Rituximab treatment strategies vary in ABOincompatible pediatric kidney transplant recipients. Here, we present the efficacy of 2 doses of rituximab and subsequent outcomes in ABO-incompatible pediatric kidney transplant patients.

MATERIALS AND METHODS

Our study of ABO-incompatible pediatric kidney transplant recipients included 21 who were pretreated with desensitization that included 2 doses of 100 mg rituximab (rituximab group) at 10 and 1 day pretransplant and 14 who received splenectomy without rituximab (splenectomy group). Both groups received immunosuppression. Basiliximab was administered during transplant and 4 days posttransplant. Double-filtration plasmapheresis and/or plasma exchange procedures were performed pretransplant in those with higher antidonor antibody titers. CD19-positive and CD20-positive B cells were measured sequentially in the rituximab group. Maximum titers of antidonor antibody pre- and posttransplant, patient and graft survival, biopsy-proven rejection, and complications/infections were compared between groups.

RESULTS

In the rituximab group, CD19- and CD20-positive B cells were depleted on transplant, persistently depleted at 3 months, and under 5% until 1 year posttransplant. Maximum titers of antidonor antibodies decreased significantly posttranplant in the rituximab (P < .001) but not in the splenectomy group (P = .174), with maximum titers posttransplant significantly lower than shown in the splenectomy group (P < .001). No rituximab patients had clinical rejection, but 5 splenectomy group patients had clinical T-cell-mediated rejection, with 2 also having antibody-mediated rejection. Six in the rituximab group had cytomegalovirus viremia but no cytomegalovirus disease; however, 5 splenectomy group recipients had cytomegalovirus disease and viremia. In the rituximab group, 3 had late-onset neutropenia. One child died of hypertrophic cardio myopathy with a functioning graft; all others survived with no failed grafts. All splenectomy group children survived, although 2 had deteriorated graft function.

CONCLUSIONS

Two doses of rituximab were effective in long-term B-cell depletion to suppress antidonor antibodies. The possibility of late-onset neutropenia must be considered.

Clinical Outcomes of ABO-Incompatible Kidney Transplantation in Patients with End-Stage Kidney Disease due to Diabetes Nephropathy

BACKGROUND

Diabetes nephropathy is one of the most common causes of end-stage kidney disease (ESKD) worldwide. The data are clear that kidney transplantation is superior to remaining on dialysis for patients with diabetes. However, there have been no reports on ABO-incompatible kidney transplantation in patients with ESKD due to diabetes nephropathy.

PATIENTS AND METHODS

We conducted a retrospective, observational study to investigate the clinical outcomes of ABO-incompatible kidney transplantation for patients with pre-existing diabetes nephropathy at our institution from April 2011 to October 2017. A total of 14 recipients were enrolled in this study.

RESULTS

All 14 patients underwent successful kidney transplantation. Both overall patient and graft survival rates were 100, 89.9, and 89.9% at 1, 3, and 5 years, respectively. One patient died 20 months after transplantation with a functioning graft due to pancreas cancer. Two of the 14 patients (14.3%) developed biopsy-proven acute cellular rejection during the follow-up period. The median observation period was 32.0 months (range 5-83 months).

CONCLUSION

ABO-incompatible kidney transplantation may be an acceptable renal replacement therapy for ESKD patients with diabetes.

Drug-Induced Hematological Cytopenia in Kidney Transplantation and the Challenges It Poses for Kidney Transplant Physicians

Drug-induced hematological cytopenia is common in kidney transplantation. Various cytopenia including leucopenia (neutropenia), thrombocytopenia, and anemia can occur in kidney transplant recipients. Persistent severe leucopenia or neutropenia can lead to opportunistic infections of various etiologies. On the contrary, reducing or stopping immunosuppressive medications in these events can provoke a rejection. Transplant clinicians are often faced with the delicate dilemma of balancing cytopenia and rejection from adjustments of immunosuppressive regimen. Differentials of drug-induced cytopenia are wide. Identification of culprit medication and subsequent modification is also challenging. In this review, we will discuss individual drug implicated in causing cytopenia and correlate it with corresponding literature evidence.

Neutropenia in pediatric heart transplant recipients

Neutropenia has been reported in pediatric heart transplant recipients, but its association with infectious morbidity and mortality is unknown. We sought to determine neutropenia's prevalence and impact on infection, rejection, and survival. A retrospective analysis of pediatric heart transplant recipients from March 2005 to August 2015 was performed. Demographics, medications, infection, and rejection data were collected. Of 142 pediatric heart transplant recipients, 77 (54.2%) developed neutropenia within 4.7 months [3.3-12.1 months] of transplant. In all patients, the adjusted 5-year cumulative incidence of neutropenia was 30.2%. Fifty-one patients (66.2%) had recurrent neutropenia. Six of 14 tested had positive antineutrophil antibodies. Medications associated with neutropenia were decreased in 15 (19.5%) and discontinued in 42 (54.4%) patients with no change in 1-year rejection rates compared to published data. Fifteen patients developed infection within 30 days of neutropenia and two from 30 days to 1 year, with an infection rate similar to the non-neutropenic group. There was no significant difference in survival, ANC, rate of rejection or PTLD in neutropenic patients with and without infection at median follow-up (5.5 years). Neutropenia is common in pediatric heart transplant recipients. Neutropenia had <20% risk of associated infection, similar to non-neutropenic patients. Infection in neutropenic patients did not increase mortality.

Rituximab-Related Late-Onset Neutropenia in Kidney Transplant Recipients Treated for Antibody-Mediated Acute Rejection

OBJECTIVES

Kidney transplant is a new area for use of rituximab, which is being used to treat acute antibody-mediated rejection or as an induction agent in ABO- or HLA-incompatible grafts. We report on late-onset neutropenia in rituximab-treated kidney transplant recipients with antibody-mediated rejection.

MATERIALS AND METHODS

This observational prospective study was performed on kidney transplant recipients with clinically suspicious or biopsy-proven antibody-mediated rejection treated with plasmapheresis plus intravenous immunoglobulin with (cases) or without (controls) rituximab.

RESULTS

Compared with none of the controls, 4 of 6 patients (66.7%) in the rituximab-treated group experienced late-onset neutropenia 35 to 93 days after the last dose of rituximab. The course of neutropenia was complicated by endocarditis in 1 patient, resulting in his death just because of a lack of valvular surgery.

CONCLUSIONS

Increased use of rituximab to treat antibody-mediated rejection among kidney transplant recipients requires attention to its late-onset adverse event, neutropenia. Although asymptomatic in some patients, kidney transplant recipients treated concomitantly with plasmapheresis and mycophenolate mofetil are predisposed to hypogammaglobulinemia, and monitoring of patients for infections is required.

ABO-Incompatible Living Kidney Transplant Recipients from Spousal Donors Receiving Rituximab

INTRODUCTION

We summarized our experience with ABO-incompatible living kidney transplant recipients from spousal donors receiving rituximab.

PATIENTS AND METHODS

Between June 2006 and December 2014, 82 patients with end-stage renal disease underwent living donor kidney transplantation at Osaka City University Hospital, of which 23 cases were ABO-incompatible transplantation between spouses with rituximab induction. We analyzed these recipients, focusing on their immunosuppressive protocols, frequency of acute rejections, and patient/graft survivals.

RESULTS

Patient and graft survival rates were 100%. The incidence of acute cellular rejection (ACR) was 30.4%. One patient experienced antibody-mediated rejection (AMR) and intractable ACR, 2 had AMR, and 2 had intractable ACR episodes that were treated using thymoglobulin.

CONCLUSIONS

This study demonstrated that ABO-incompatible kidney transplantation between spouses using rituximab is a radical but effective treatment for end-stage renal disease. However, this procedure could be immunologically high risk due to ABO-incompatibility and poor histocompatibility.

Clinical Outcome of Elderly Kidney Transplant Recipients from Spousal Donors

INTRODUCTION

Patients aged 60 years and older stand for the fastest growing group of patients with end-stage renal disease worldwide, and the need for kidney transplants among this population is rising. In Japan, living donor kidney transplantation is mainly performed to deal with the severe shortage of deceased donors, and the number of spousal transplants is currently increasing.

PATIENTS AND METHODS

A total of 164 patients with ESRD underwent living donor kidney transplantation at our institution, of whom 21 patients aged 60 years and older had spousal kidney transplantation. ABO-incompatible kidney transplantation was performed in 5 of the 21 cases. We analyzed these recipients.

RESULTS

Patient and graft survival rates were 100%. The incidence of acute rejection was 23.8%. Eight patients experienced cytomegalovirus viremia, two patients experienced Pneumocystis jiroveci infection, and one experienced bacterial pneumonia. Two patients developed cancers and underwent curative operation after transplantation.

CONCLUSIONS

Elderly kidney transplantation from spousal donors is associated with age-related immune dysfunction, which may develop infections and malignancies and could be immunologically high risk due to the high rate of ABO-incompatibility and poor histocompatibility. An effort to minimize the adverse effect of immunosuppression and to reduce the risk of acute rejection may be needed for an excellent long-term outcome.

IL-10-overexpressing B cells regulate innate and adaptive immune responses

BACKGROUND

Distinct human IL-10-producing B-cell subsets with immunoregulatory properties have been described. However, the broader spectrum of their direct cellular targets and suppressive mechanisms has not been extensively studied, particularly in relation to direct and indirect IL-10-mediated functions.

OBJECTIVE

The aim of the study was to investigate the effects of IL-10 overexpression on the phenotype and immunoregulatory capacity of B cells.

METHODS

Primary human B cells were transfected with hIL-10, and IL-10-overexpressing B cells were characterized for cytokine and immunoglobulin production by means of specific ELISA and bead-based assays. Antigen presentation, costimulation capacity, and transcription factor signatures were analyzed by means of flow cytometry and quantitative RT-PCR. Effects of IL-10-overexpresing B cells on Toll-like receptor-triggered cytokine release from PBMCs, LPS-triggered maturation of monocyte-derived dendritic cells, and tetanus toxoid-induced PBMC proliferation were assessed in autologous cocultures.

RESULTS

IL-10-overexpressing B cells acquired a prominent immunoregulatory profile comprising upregulation of suppressor of cytokine signaling 3 (SOCS3), glycoprotein A repetitions predominant (GARP), the IL-2 receptor α chain (CD25), and programmed cell death 1 ligand 1 (PD-L1). Concurrently, their secretion profile was characterized by a significant reduction in levels of proinflammatory cytokines (TNF-α, IL-8, and macrophage inflammatory protein 1α) and augmented production of anti-inflammatory IL-1 receptor antagonist and vascular endothelial growth factor. Furthermore, IL-10 overexpression was associated with a decrease in costimulatory potential. IL-10-overexpressing B cells secreted less IgE and potently suppressed proinflammatory cytokines in PBMCs, maturation of monocyte-derived dendritic cells (rendering their profile to regulatory phenotype), and antigen-specific proliferation in vitro.

CONCLUSION

Our data demonstrate an essential role for IL-10 in inducing an immunoregulatory phenotype in B cells that exerts substantial anti-inflammatory and immunosuppressive functions.