Infectious risks and optimal strength of maintenance immunosuppressants in rituximab-treated kidney transplantation

Outcome of ABO Blood Type-Incompatible Living-Related Donor Kidney Transplantation Under a Contemporary Immunosuppression Strategy in Japan

BACKGROUND

Because of the serious donor shortage in Japan, there is an increasing need for ABO blood type-incompatible kidney transplantation (ABOi-KT) in living-related donor kidney transplantation. We evaluated the outcomes of ABOi-KT performed at our hospitals using a contemporary immunosuppression strategy with low-dose rituximab.

PATIENTS AND METHODS

Between June 2006 and April 2019, 107 patients underwent living-related donor kidney transplantation at our hospitals. The patients were divided into ABO-compatible (ABOc) and ABOi groups. The basic immunosuppression regimen differed between the 2 groups in the use of low-dose rituximab and therapeutic apheresis in the ABOi group. We compared graft survival, patient survival, rejection, viral infection, and posttransplant renal function between the 2 groups.

RESULTS

Of 107 recipients, 37 (35%) underwent ABOi-KT. The 5-year graft survival rates in the ABOc and ABOi group were 91% and 100%, respectively. The Kaplan-Meier analyses showed no difference in graft survival (P = .168) or patient survival (P = .873) between the groups. Biopsy-proven rejection in the ABOc and ABOi groups was observed in 13 (19%) and 7 (19%) patients, respectively (P = .965), and viral infection was observed in 21 (30%) and 10 (27%) patients (P = .747), respectively. Renal function by estimated glomerular filtration rate from 1 week to 5 years after transplantation was similar in both groups.

CONCLUSIONS

The outcomes of ABOi-KT with low-dose rituximab were comparable with those of ABOc-KT at our hospitals. ABOi-KT with proper immunosuppression may be an option to help resolve the severe donor shortage in Japan.

Percentage of CD19+ Cells in Peripheral Blood Lymphocytes After Rituximab-Based Desensitization as a Predictor of Acute Antibody-Mediated Rejection in ABO-Incompatible Kidney Transplantation

BACKGROUND

Rituximab (RIT) is effective as a part of the desensitization therapy before ABO-incompatible kidney transplantation (ABOi-KTx), and a single dose of RIT at 375 mg/m² or less is recommended. However, adequate RIT dose recommendations have not yet been established for individual recipients. Therefore, we evaluated the relationship between the proportion of B cells in peripheral blood and acute antibody-mediated rejection (AAMR).

METHODS

Forty-four consecutive ABOi-KTx recipients were enrolled in this retrospective study. Before transplantation, subjects were treated with RIT at various doses, ranging from 65 to 400 mg/body (46-263 mg/m²), followed by plasmapheresis and intravenous immunoglobulin as a desensitization therapy. The percentage of CD19⁺ cells in the total peripheral blood lymphocytes population (%CD19) was determined the day before transplantation. Transplant recipients were divided into 2 groups according to pretransplant %CD19, as follows: low %CD19 group, ≤ 1.2% (n = 35) and high %CD19 group, > 1.2% (n = 9). The relationship between %CD19 and incidence of AAMR was evaluated, and the predicting factors for AAMR incidence were determined by univariate and multivariate analyses.

RESULTS

The incidence of AAMR was significantly higher in the high %CD19 group than in the low %CD19 group (44.4% vs 5.7%, P = .006). Furthermore, multivariate analysis showed that %CD19 > 1.2% was the only independent factor to predict AAMR, with an odds ratio of 14.31 (P = .038).

CONCLUSION

High %CD19 values after rituximab administration in ABOi-KTx recipients implies insufficient depletion of B cells, which can lead to AAMR.

Infectious Complications in Adult ABO-Incompatible Liver Transplantation: Our Preliminary Experience

The number of ABO-incompatible living donor liver transplantations (ABO-I LDLT) has increased owing to the use of preoperative rituximab for immunosuppression. However, controversy remains regarding adequate immunosuppression owing to rejection and infection. Here, we present 5 cases of our ABO-I LDLT experience, emphasizing rejection and infectious complications, retrospectively. The treatment protocol included prophylactic rituximab followed by plasma exchange prior to transplantation, splenectomy, and immunosuppressive and prophylactic antibiotic regimens after transplantation. Four of the 5 patients also received local infusion therapy via the portal vein. Neither hyperacute nor antibody-mediated rejection occurred. All grafts were functioning well at discharge. Rehospitalization was required for 2 patients due to severe infection within 6 months of transplantation. Invasive aspergillosis was successfully treated in 1 patient, but the other patient died from severe sepsis with overwhelming postsplenectomy infection syndrome. Our results confirm that, although improved immunosuppressive therapy markedly reduces rejection in ABO-I LDLT, it is also associated with an increased risk of various life-threatening infections.

ABO-incompatible kidney transplantation as a renal replacement therapy-A single low-volume center experience in Japan

INTRODUCTION

Living donor kidney transplantation is preferable to deceased donor transplantation due to its superior long-term patient and graft survivals. However, ABO blood group incompatibility is a major barrier to living donor kidney transplantation. ABO-incompatible kidney transplantation has been performed in Japan since the late 1980's, but it is still globally uncommon. The objective of this study is to compare the clinical outcomes of ABO-incompatible kidney transplantation (ABO-IKT) with that of ABO-compatible kidney transplantation (ABO-CKT) at an institution where only about two kidney transplants are performed a month on average.

DESIGN

A single center propensity score-matched cohort study.

PATIENTS AND METHODS

We retrospectively collected and analyzed the data of 240 patients with end-stage kidney disease (ESKD) who underwent living donor kidney transplantation at Osaka City University Hospital from January 1999 to December 2016, of which 66 patients were ABO-IKT. The remaining 174 patients who underwent ABO-CKT were studied as the control group, and the clinical outcomes of ABO-IKT and ABO-CKT recipients were compared based on propensity score matching.

RESULTS

After propensity score matching, there were no significant differences in both patient survival and death-censored graft survival rates between the ABO-IKT and ABO-CKT groups. Moreover, there were no significant differences in estimated glomerular filtration rate as well as frequency of acute cellular rejection, antibody-mediated rejection, infectious adverse events, malignancies, and post-operative bleeding between the two groups.

CONCLUSION

Currently, ABO-IKT may be an acceptable treatment for patients with ESKD even at a low-volume transplant center.

Rituximab for immunologic renal disease: What the nephrologist needs to know

Rituximab (RTX), a chimeric, monoclonal anti-CD20 antibody, is increasingly used in immune-mediated renal diseases. While licensed in the induction treatment of ANCA-associated vasculitis, it represents one of the most commonly prescribed off-label drugs. Much of the information regarding its safety has been drawn from experience in hematology and rheumatology. Ample evidence illustrates the safety of RTX, however, rare but serious adverse events have emerged that include progressive multifocal leucoencephalopathy and hepatitis B reactivation. Moderate to severe hypogammaglobulinemia and late-onset neutropenia following RTX therapy confer an increased infectious risk and factors predicting these side effects (i.e. a genetic basis) need to be identified. Nephrologists initiating RTX need to bear in mind that long-term risks and optimal dosing for many renal indications remain unclear. Special considerations must be given when RTX is used in women of childbearing age. We summarize practical aspects concerning the use of RTX. This review will provide nephrologists with information to guide their use of RTX alerting them to safety risks and the need for patient counselling.

Safety and efficacy of mizoribine treatment in nephrotic syndrome complicated with hepatitis B virus infection: a clinical study

Objective The objective of this study is to explore the efficacy and safety of mizoribine (MZR) in treating nephrotic syndrome patients afflicted with hepatitis B virus (HBV). Methods The present study included 36 nephrotic syndrome patients accompanied with HBV infection. A draft of MZR (150-200 mg/d), methylprednisolone (0.6-0.8 mg/kg·d), and entecavir (0.5 mg/d) was administered to study patients over 24 weeks. The serum albumin (AlB), 24-h urine protein (24-U-TP), liver and renal functions, and HBV-DNA were quantified before and at 2, 4, 8, 12, 16, 20, and 24 weeks after the treatment. The adverse responses were recorded. Results The AlB levels of patients increased gradually after comprehensive treatment, while the 24-U-TP, serum cholesterol, and triglyceride (TG) levels declined gradually. The changes at 24 weeks post-treatment were statistically significant. Compared with the levels before treatment, the HBV-DNA, transaminase, and renal functions of the patients were not significantly altered after the treatment. No evident adverse response was found. Conclusion Treatment using MZR in combination with methylprednisolone and entecavir in HBV-positive nephrotic syndrome patients displays significant efficacy with a low incidence of adverse reactions.

Low dose of mycophenolate mofetil is enough in desensitized kidney transplantation using rituximab

Background

Rituximab is widely used in kidney transplantation. However, it is not clear whether the conventional doses of maintenance immunosuppressant in rituximab-treated kidney transplantation (KT) are appropriate. In our previous study, decreasing mycophenolate mofetil (MMF) dose due to infection did not increase the incidence of rejection or graft failure. Based on these experiences, we developed a new protocol with a lower dose of MMF and studied its clinical outcomes in rituximab-treated KT.

Methods

We enrolled all patients who underwent ABO-incompatible or human leukocyte antigen (HLA)-sensitized living donor KT with the new immunosuppressant protocol after preconditioning with rituximab, but without splenectomy from November 2011 to May 2013. Seventy-two patients (group 1) were consecutively enrolled in this study and followed until November 2013. Patients from our previous study served as control groups. Sixty-seven patients received KT using rituximab with a conventional dose of MMF (group 2), and 87 patients received ABO compatible KT without need for rituximab (group 3). Clinical outcomes, including rejection, infection, and graft survival, were compared between the groups. The χ² test and Fisher’s exact test were used for categorical variables, the Student’s t-test and Mann-Whitney U test were used for continuous variables, and a log-rank test was used for mortality analysis.

Results

Doses of postoperative MMF (g/day) were lower in group 1 than in the other groups (1.03 ± 0.19, 1.48 ± 0.34 and 1.48 ± 0.32 g/day at 1 week, p < 0.001). Infectious complications occurred more often in groups with conventional MMF doses (group 2 and 3) than in group 1 (16.7 vs. 37.3 %, p = 0.007 and 16.7 vs. 34.5 %, p = 0.012, respectively). Notably, group 1 showed a lower incidence of cytomegalovirus infection than group 2. However, reduction in MMF dose did not increase the incidence of acute rejection (4.2, 4.5 and 10.3 %). Only one graft failure occurred in group 2 due to vessel kinking after operation. There were no significant differences in the incidence of malignancy and mortality between groups.

Conclusions

A low MMF dose reduces infection without increasing rejection or graft loss and it may be appropriate to reduce the dose of MMF for rituximab-treated KT patients.

Outcome comparison of ABO-incompatible kidney transplantation with low-dose rituximab and ABO-compatible kidney transplantation: a single-center experience

BACKGROUND

The development of immunosuppressive techniques has helped overcome the ABO incompatibility barrier. However, the outcomes of ABO-incompatible (ABOi) kidney transplantation remain a controversial issue with the advent of the anti-CD20 chimeric antibody rituximab. Herein, we report the outcomes of ABOi kidney transplantation with low-dose rituximab.

PATIENTS AND METHODS

Between June 2006 and April 2013, 42 patients underwent living-related kidney transplantation at our hospital. The patients were divided into 2 groups: ABO-compatible (ABOc; n = 29) and ABOi kidney transplants using low-dose rituximab (100 mg/m(2)) without splenectomy (n = 13). The basic immunosuppression regimen (calcineurin inhibitor [CNI], mycophenolate mofetil [MMF], and steroids) was the same for both groups, except for the use of rituximab and therapeutic apheresis in the ABOi group. We compared post-transplantation renal function, incidents of virus infection, episodes of rejection, and graft survival between the 2 groups.

RESULTS

In our hospital, 30% of recipients received ABOi kidney transplants. The estimated glomerular filtration rate (eGFR) did not differ between the groups. Rejection episodes confirmed by biopsy in the ABOc and ABOi groups were 8 (28%) and 4 (31%) patients (P = .833), acute antibody-mediated rejection was observed in 1 (3.5%) and 2 (15%) patients (P = .165), and virus infection was observed in 14 (48%) and 3 (23%) patients (P = .252), respectively. The 5-year patient survival rate was 100% in both groups, and the 5-year graft survival rates were 95% for ABOc and 100% for ABOi transplants (P = .527).

CONCLUSIONS

These results suggest that the outcomes of ABOi kidney transplantation with low-dose rituximab are similar to those of ABOc kidney transplantation. Further study is necessary to address the efficacy and safety of ABOi kidney transplantation.

Cytomegalovirus enhances macrophage TLR expression and MyD88-mediated signal transduction to potentiate inducible inflammatory responses

Circulating monocytes carrying human CMV (HCMV) migrate into tissues, where they differentiate into HCMV-infected resident macrophages that upon interaction with bacterial products may potentiate tissue inflammation. In this study, we investigated the mechanism by which HCMV promotes macrophage-orchestrated inflammation using a clinical isolate of HCMV (TR) and macrophages derived from primary human monocytes. HCMV infection of the macrophages, which was associated with viral DNA replication, significantly enhanced TNF-α, IL-6, and IL-8 gene expression and protein production in response to TLR4 ligand (LPS) stimulation compared with mock-infected LPS-stimulated macrophages during a 6-d in vitro infection. HCMV infection also potentiated TLR5 ligand-stimulated cytokine production. To elucidate the mechanism by which HCMV infection potentiated inducible macrophage responses, we show that infection by HCMV promoted the maintenance of surface CD14 and TLR4 and TLR5, which declined over time in mock-infected macrophages, and enhanced both the intracellular expression of adaptor protein MyD88 and the inducible phosphorylation of IκBα and NF-κB. These findings provide additional information toward elucidating the mechanism by which HCMV potentiates bacteria-induced NF-κB-mediated macrophage inflammatory responses, thereby enhancing organ inflammation in HCMV-infected tissues.

Long-term outcome of pediatric renal transplantation: a single center study in Japan

Little is known about the risk factors for long-term poor outcome in pediatric renal transplantation. Between 1973 and 2010, 111 renal transplants (92 living donations) were performed in 104 children (56 males, mean age, 12.5 yr) at the Social Insurance Chukyo Hospital, and followed-up for a mean period of 13.6 yr. The patient survival at 1, 5, 10, 15, 20 (living- and deceased-donor transplants), and 30 yr (living-donor transplants only) was 98.1%, 92.8%, 87.8%, 84.9%, 82.6%, and 79.3%. The graft survival at 1, 5, 10, 15, 20, and 30 yr was 92.0%, 77.3%, 58.4%, 50.8%, 38.5%, and 33.3%. The most common cause of graft loss was CAI, AR, death with functioning, recurrent primary disease, ATN, and malignancy. Donor gender, ATN, malignancy/cardiovascular events, and eras affected patient survival. AR and CAI were the risk factors for graft loss. The evolved immunosuppression protocols improved the outcome by reducing AR episodes and ATN but not CAI, suggesting CAI as the major risk factor for graft loss. CAI was correlated with AR episodes, CMV infection, and post-transplant hypertension. Strategies for preventing the risk factors for malignancy/cardiovascular events and CAI, including hypertension/infection, are crucial for better outcomes.

ABO incompatible renal transplants: Good or bad?

ABO incompatible kidney transplantation (ABOi-KT) was previously considered to be an absolute contraindication for patients with end-stage kidney disease (ESKD) due to hyperacute rejection related to blood type barrier. Since the first successful series of ABOi-KT was reported, ABOi-KT is performed increasingly all over the world. ABOi-KT has led to an expanded donor pool and reduced the number of patients with ESKD awaiting deceased kidney transplantation (KT). Intensified immunosuppression and immunological understanding has helped to shape current desensitization protocols. Consequently, in recent years, ABOi-KT outcome is comparable to ABO compatible KT (ABOc-KT). However, many questions still remain unanswered. In ABOi-KT, there is an additional residual immunological risk that may lead to allograft damage, despite using current diverse but usually intensified immunosuppressive protocols at the expense of increasing risk of infection and possibly malignancy. Notably, in ABOi-KT, desensitization and antibody reduction therapies have increased the cost of KT. Reassuringly, there has been an evolution in ABOi-KT leading to a simplification of protocols over the last decade. This review provides an overview of the history, outcome, protocol, advantages and disadvantages in ABOi-KT, and focuses on whether ABOi-KT should be recommended as a therapeutic option of KT in the future.

Effects of Rituximab on the Development of Viral and Fungal Infections in Renal Transplant Recipients

Background. Rituximab is becoming increasingly utilized in renal transplant recipients; however, its association with infections remains unclear. Methods. We reviewed the incidence of viral and fungal infections in kidney transplant recipients treated with () or without () rituximab (RTX) in addition to standard immunosuppression. Results. Infections occurred in 134 (30%) patients, with a greater proportion in RTX versus no RTX patients (47% versus 28%; ). Viral infections occurred in 44% and 27% of RTX and no RTX patients, respectively (). This was largely driven by the frequency of BK viremia and noncytomegalovirus/non-BK viruses in RTX patients (27% versus 13% () and 15% versus 2% (), resp.). Fungal infections also occurred more often in RTX patients (11% versus 3 %; ). Multivariate analysis revealed deceased donor recipient (odds ratio = 2.5; ) and rituximab exposure (odds ratio = 2.2; ) as independent risk factors for infection. Older patients, deceased donor recipients, those on dialysis longer, and those with delayed graft function tended to be at a greater risk for infections following rituximab. Conclusions. Rituximab is associated with an increased incidence of viral and fungal infections in kidney transplantation. Additional preventative measures and/or monitoring infectious complications may be warranted in those receiving rituximab.

CTLA4 gene polymorphisms influence the incidence of infection after renal transplantation in Chinese recipients

Background

Immunosuppressive therapy is usually administered following renal transplantation to protect the graft from rejection. However, this often causes complications such as infections to occur. Single nucleotide polymorphisms (SNPs) within the CTLA4 gene, such as −1772T/C (rs733618), +49A/G (rs231775) and +6230 G/A (rs3087243), can affect graft rejection and the long-term clinical outcome of organ transplantation. The role of CTLA4 SNPs in T cell-mediated immunity in renal transplantation and association with infection after transplantation is unknown.

Methods

In this study, the risk of infection according to CTLA4 SNPs was investigated in 304 patients who received kidney graft transplants between 2008 and 2012.

Results

The frequency of the rs4553808 GG genotype was significantly higher in recipients with viral infection (14.89%) than in those without infections (3.50%) (Bonferroni-adjusted p = 0.005). A significant difference (p = 0.001) in patients with the rs4553808 GG genotype from those with the AA+AG genotypes was found in the viral cohort using the log-rank test. A significant association was found between the rs4553808 genotype and onset of viral infection in transplant recipients (p = 0.001). The frequencies of the CGTAG and CGCAG haplotypes were significantly higher in the viral infection group (9.6% and 5.3%) than in the non-viral infection group (3.8% and 1.4%) (p = 0.0149 and p = 0.0111). No association between any CTLA4 SNP and bacterial infection was found. Multivariate analyses revealed that one risk factor, the use of antibody induction therapy (p = 0.007), was associated with bacterial infection, and two risk factors, antibody use (p = 0.015) and recipient rs4553808 genotype (p = 0.001), were associated with viral infection.

Conclusions

The rs4553808 GG genotype may be a risk factor for viral infection in kidney transplantation. The CTLA4 haplotypes CGTAG and CGCAG were partially associated with the development of viral infection in Chinese kidney transplant recipients.

Progressive multifocal leukoencephalopathy in a heart transplant recipient following rituximab therapy for antibody-mediated rejection

We report the case of a male heart transplant recipient who developed acute antibody-mediated rejection and was treated with 5 weeks of a rituximab-containing regimen. Two months later he presented with progressive motor and cognitive impairments and was diagnosed with progressive multifocal leukoencephalopathy (PML). He was treated with reduction of his immunosuppressive medications, mirtazapine, IVIG and plasmapheresis. He died within weeks. We reviewed the current literature on PML and its association with immunosuppression, highlighting its impact in the setting of solid organ transplantation and considering the potential effect of newer biologic drugs on the incidence of this devastating disease in the transplant population.

Incompatible kidney transplantation: a brief overview of the past, present and future

Live kidney donor transplantation across immunological barriers, either blood group or positive crossmatch [ABO- and human leucocyte antigens (HLA)-incompatible kidney transplantation, respectively], is now practised widely across many transplant centres. This provides transplantation opportunities to patients that hitherto would have been deemed contra-indicated and would subsequently have waited indefinitely for a suitably matched kidney. Protocols have evolved with time as experience has grown and now a variety of desensitization strategies are currently practised to overcome such immunological barriers. In addition, desensitization protocols are complemented by kidney paired donation exchange schemes and therefore incompatible patients now have strategies to either confront or bypass immunological barriers, respectively. As the field expands it is clear that non-transplant clinicians will be exposed to incompatible kidney transplant recipients outside of experienced centres. It is therefore timely to review the evolution of practice that have led to current desensitization modalities, contrast protocols and outcomes of current regimens and speculate on future direction of incompatible kidney transplantation.