Tacrolimus trough levels higher than 6 ng/mL might not be required after a year in stable kidney transplant recipients.

BACKGROUND: Little is known regarding optimal tacrolimus (TAC) trough levels after 1 year post-transplant in stable kidney transplant recipients (KTRs) who have not experienced renal or cardiovascular outcomes. This study aimed to investigate the effect of 1-year post-transplant TAC trough levels on long-term renal and cardiovascular outcomes and opportunistic infections in stable KTRs. METHODS: KTRs receiving TAC with mycophenolate-based immunosuppression who did not experience renal or cardiovascular outcomes within 1 year post-transplant were enrolled from a multicenter observational cohort study. Renal outcome was defined as a composite of biopsy-proven acute rejection, interstitial fibrosis and tubular atrophy, and death-censored graft loss. Cardiovascular outcome was defined as a composite of de novo cardiomegaly, left ventricular hypertrophy, and cardiovascular events. Opportunistic infections were defined as the occurrence of BK virus or cytomegalovirus infections. RESULTS: A total of 603 eligible KTRs were divided into the low-level TAC (LL-TAC) and high-level TAC (HL-TAC) groups based on a median TAC level of 5.9 ng/mL (range 1.3-14.3) at 1 year post-transplant. The HL-TAC group had significantly higher TAC trough levels at 2, 3, 4, and 5 years compared with the levels of the LL-TAC group. During the mean follow-up of 63.7 ± 13.0 months, there were 121 renal outcomes and 224 cardiovascular outcomes. In multivariate Cox regression analysis, LL-TAC and HL-TAC were not independent risk factors for renal and cardiovascular outcomes, respectively. No significant differences in the development of opportunistic infections and de novo donor-specific anti-human leukocyte antigen antibodies and renal allograft function were observed between the two groups. CONCLUSIONS: TAC trough levels after 1 year post-transplant remained at a similar level until the fifth year after kidney transplantation and were not directly associated with long-term outcomes in stable Korean KTRs who did not experience renal or cardiovascular outcomes. Therefore, in Asian KTRs with a stable clinical course, TAC trough levels higher than approximately 6 ng/mL might not be required after a year of kidney transplantation.

JC Polyomavirus Infection Potentiated by Biologics.

The risk of JC polyomavirus encephalopathy varies among biologic classes and among agents within the same class. Of currently used biologics, the highest risk is seen with natalizumab followed by rituximab. Multiple other agents have also been implicated. Drug-specific causality is difficult to establish because many patients receive multiple immunomodulatory medications concomitantly or sequentially, and have other immunocompromising factors related to their underlying disease. As use of biologic therapies continues to expand, further research is needed into pathogenesis, treatment, and prevention of JC polyomavirus encephalopathy such that risk for its development is better understood and mitigated, if not eliminated altogether.

Clinical Characteristic and Outcomes of BK Virus Infection in Kidney Transplant Recipients Managed Using a Systematic Surveillance and Treatment Strategy.

BACKGROUND: BK virus (BKV)-associated nephropathy is a significant complication of kidney transplantation that progresses to graft dysfunction and graft loss. The aim of this study was to know the infection rate and progression of BKV according to our strategy. MATERIALS AND METHODS: This study included 302 patients who received kidney transplantation between August 2010 and October 2012. Patients were divided into 4 groups: no BK infection, BK viruria only, low BK viremia, and high BK viremia. RESULTS: In this study, 57 patients had BK viremia (18.9%), and 18 patients had BK nephropathy (5.9%) during a 2-year follow-up period. Age, sex, cytomegalovirus (CMV) viremia, existence of donor-specific antibodies, type of transplantation, and delayed graft function were not significantly different. Disappearance of BKV infection was better in the viruria and low viremia groups than in the high viremia group (P = .001), and duration of BK infection was longer in the high viremia group than the low viremia group (P = .002). CONCLUSION: All diagnosed cases of BKV nephropathy were in the high BK viremia group. For BK viruria and viremia, early detection of BK infection together with early intervention by reduced immunosuppressant is a useful strategy to maintain allograft function. Long-term follow up is required to identify the risk factors for BK infection and graft survival after kidney transplantation.

Alemtuzumab induction for retransplantation after primary transplant with alemtuzumab induction
.

BACKGROUND: Lymphocyte-depleting induction with alemtuzumab (ALEM) or rabbit antithymocyte-globulin (rATG) is commonly used at retransplantation. It is unknown which agent is preferable, particularly when ALEM was used at primary transplant. OBJECTIVE: Evaluate outcomes after ALEM at retransplant following primary transplant with ALEM induction (ALEM-ALEM) as compared to retransplant with rATG (ALEM-rATG). MATERIALS AND METHODS: Single-center, observational cohort study of adult patients receiving kidney or pancreas transplant between January 1, 2001 and December 12, 2016. RESULTS: 45 patients (16 ALEM-ALEM and 29 ALEM-rATG) met inclusion criteria. The ALEM-ALEM group had fewer days between transplants (621.0 ± 821.8 vs. 2,024.4 ± 1,285.8, p = 0.049), lower panel-reactive-antibodies (PRA) prior to transplant 2 (15.7 ± 31.5 vs. 53.2 ± 37.8; p = 0.0003), and more pancreas secondary transplants, although this was not statistically significant (ALEM-ALEM 37.5% vs. ALEM-rATG 10.3%, p = 0.05). The ALEM-ALEM group experienced a significantly higher rate of fungal infection (ALEM-ALEM 46.8% vs. ALEM-rATG 11.3%, p = 0.02). When adjusted in a multivariate model, this trend persisted (HR 3.97, CI 0.95 - 16.5, p = 0.05). A subgroup analysis of patients receiving a kidney for both transplant 1 and 2 to remove the possible confounding effect of pancreas allografts also found incidence of fungal infection at 1 year to be significantly higher in the ALEM-ALEM group (ALEM-ALEM 25% vs. ALEM-rATG 9.3%, p = 0.025). Rejection rates were not different between groups at 1 year (ALEM-ALEM 25% vs. ALEM-rATG 24.2%). Rates of cytomegalovirus (CMV) infection, BK polyomavirus infection, patient and graft survival were also similar. CONCLUSION: Patients with repeat courses of ALEM induction across multiple transplants may have a higher incidence of fungal infection. Future studies are needed to explore this risk, particularly in light of current drug manufacturer allocation practices and potential increased utilization by transplant centers.

A delicate balance between rejection and BK polyomavirus associated nephropathy; A retrospective cohort study in renal transplant recipients.

BACKGROUND: The immunosuppressive agents mycophenolate acid (MPA) and tacrolimus (Tac) are associated with a higher incidence of BK polyomavirus nephropathy (BKPyVAN). In this observational retrospective cohort study, the frequency of BK polyomavirus (BKPyV) complications over a 24-month period was studied. METHODS: 358 renal transplant recipients (RTR) treated with MPA, with either cyclosporine A (CsA) (CsAM group) or Tac (TacM group) and mostly prednisolone, were included. RESULTS: Incidence of BKPyV-viremia was not significantly different between the CsAM (n = 42/191) (22.0%) and the TacM (n = 36/167) (21.6%) group. Biopsy proven BKPyVAN occurred more often in the TacM group (6.6%) versus the CsAM group (2.1%) (p = 0.03). Longitudinal data analysis showed a significant earlier decline of viral load in plasma in the CsAM group compared to the TacM group (p = 0.005). The incidence of biopsy proven acute rejection (BPAR) was significantly higher in the CsAM (19.9%) compared to the TacM (10.8%) (p = 0.02) group. Graft loss, estimated glomerular filtration rate and mortality rate did not differ in both treatment groups. CONCLUSION: In conclusion, this study shows that immunosuppressive treatment with Tac and MPA compared to CsA and MPA is associated with a lower incidence of BPAR, but at the cost of an increased risk of developing BKPyVAN in the first two years post-transplant.

Polyomavirus-associated Prostatitis in Wistar Han Rats Following Immunosuppression in a Chronic Toxicity Study.

Chronic prostatitis characterized on light microscopic examination by moderate, multifocal, predominantly lymphocytic inflammation associated with epithelial atypia and intranuclear and cytoplasmic inclusion-like material was identified in the prostate gland of 2 Wistar Han rats administered an immunomodulatory test article in a 6-month chronic toxicity study. Transmission electron microscopy of the prostate glands identified 45-nm, nonenveloped, icosahedral virions arranged in paracrystalline array within the cell nuclei in 1 of the 2 rats. The size, shape, location, and array pattern were most consistent with a polyomavirus. The light and electron microscopic findings after immunosuppression in our case have a resemblance to a polyomavirus recently reported to affect prostate gland epithelium in a colony of immunocompromised X-linked severe combined immune deficiency rats. To the best of our knowledge, this is the first report of light and electronic microscopic lesions in the reproductive tract associated with polyomavirus following chronic immunosuppression in a widely used, wild-type Wistar Han rat.

BK and Other Polyomaviruses in Kidney Transplantation.

For more than 40 years, polyomaviruses (BK virus and JC virus) have been known to cause disease in human beings. Recently, 11 new polyomaviruses were discovered. However, the majority of these viruses are rare in renal transplant recipients and BK and JC viruses remain the most important polyomaviruses to impact this population. BK virus presents as BK virus nephropathy and has, in rare instances, been associated with hemorrhagic cystitis or ureteral strictures. JC virus can cause progressive multifocal leukoencephalopathy or nephropathy in this population as well, but is uncommon. Antiviral prophylactic and therapeutic interventions for these diseases are lacking to date, although reduction of immunosuppression has been associated with success in treating both BK virus nephropathy and JC virus-induced disease. Risk factors are not well defined and vary across studies. However, the cumulative degree of immunosuppression is regarded universally as an important contributor to BK virus replication. For these reasons, it is recommended to screen all renal transplant recipients prospectively for BK virus infection. Multicenter trials using standardized BK and JC virus screening methods are necessary to define risk factors better, and to determine the effect of prophylaxis and treatments for these polyomaviruses affecting renal transplant recipients.

High-dose steroid therapy in BK viremia adversely affected the long-term graft function after kidney transplantation.

BACKGROUND: Although high-dose steroid therapy has been attempted for the management of clinically suspected allograft rejection, before testing for BK viral activity or acute cellular rejection accompanied by BK polyomavirus nephropathy, its long-term outcome remains unknown. We investigated the impact of high-dose steroids on BK viral activity and long-term graft outcomes in patients with BK viremia. METHODS: The study population comprised 144 kidney transplant recipients with BK viremia. They were divided into 2 groups based on the amount of steroids administered: low-dose group (<2 g, n=123) or high-dose group (≥2 g, n=21). RESULTS: The baseline serum BK viral loads were 5.4±1.1 log cp/mL in the low-dose group and 6.0±1.3 in the high-dose group (P=.054). These changed to 5.2±1.3 and 6.1±1.4, 1 month after steroid treatment (P=.03) and 4.9±1.3 and 5.9±1.4 at 2 months (P=.033), respectively. From 3 months to 1 year, the serum BK viral titers were not different between groups. Kaplan-Meier analyses demonstrated that the rates of the decline of graft function and graft failure were higher in the high-dose group (P=.02 and P=.04, respectively). High-dose steroids (P=.012, hazard ratio [HR] 5.04, 95% confidence interval [CI] 1.42-17.85) and log serum BK viral load at 2 months after steroid treatment (P=.042, HR 1.52, 95% CI 1.02-2.28) were independent risk factors for the decline of graft function. CONCLUSION: High-dose steroids induced BK viral activation and subsequently resulted in poor long-term graft function and early graft failure in patients with BK viremia.

BK Virus Nephropathy in Heart Transplant Recipients.

Polyomavirus-associated nephropathy (PVAN) has become an important cause of kidney failure in kidney transplant recipients. PVAN is reported to affect 1% to 7% of kidney transplant recipients, leading to premature transplant loss in approximately 30% to 50% of diagnosed cases. PVAN occurring in the native kidneys of solid-organ transplant recipients other than kidney only recently has been noted. We report 2 cases of PVAN in heart transplant recipients, which brings the total of reported cases to 7. We briefly review the literature on the hypothesized causes of PVAN in kidney transplant recipients and comment on whether these same mechanisms also may cause PVAN in other solid-organ transplant recipients. PVAN should be considered in the differential diagnosis when evaluating worsening kidney function. BK viremia surveillance studies of nonkidney solid-organ recipients should be conducted to provide data to assist the transplantation community in deciding whether regular monitoring of nonkidney transplant recipients for BK viremia is indicated.

First confirmed case of native polyomavirus BK nephropathy in a liver transplant recipient seven years post-transplant.

Renal dysfunction frequently occurs in liver transplant recipients and is associated with increased morbidity and mortality. BK virus is a human polyoma virus that reactivates during immunocompromised states and is a known cause of renal allograft dysfunction in renal transplant recipients. However, BK nephropathy of native kidneys is rare in non-renal transplant recipients. There is no published data linking BK virus and renal dysfunction in liver transplant recipients. We describe the first confirmed case of native polyomavirus BK nephropathy in a liver transplant recipient. BK nephropathy should be considered in the differential diagnosis of new renal failure in liver transplant recipients.

Increased BK viremia and progression to BK-virus nephropathy following high-dose intravenous immunoglobulin for acute cellular rejection.

BK virus nephropathy and cellular rejection are common causes of allograft dysfunction in renal transplant recipients. The two can be difficult to distinguish on allograft biopsy and can be present simultaneously. Management of the patient with coexistent BK infection and rejection is complicated by the conflicting ideals of decreasing immunosuppression to treat the former and increasing immunosuppression to treat the latter. The authors present the case of a 57-year-old renal transplant recipient who underwent allograft biopsy 8 weeks post-transplant for evaluation of increased serum creatinine in the setting of BK viremia (BKV). Biopsy revealed Banff classification 1b acute cellular rejection, with insufficient evidence to diagnose BK virus-associated nephropathy. The patient was administered intravenous immune globulin (IVIG), with no other changes in immunosuppressive therapy. Plasma and urine BK increased exponentially following IVIG administration, and allograft function further deteriorated. Repeat biopsy showed overt BK viral nephropathy, and BKV and creatinine decreased only after reduction in immunosuppression and initiation of leflunomide. Although case series have suggested a potential role for IVIG in the setting of BK infection, further study is needed to define the safety and efficacy of this approach.

The risk of progressive multifocal leukoencephalopathy under biological agents used in the treatment of chronic inflammatory diseases.

Biological agents such as monoclonal antibodies and soluble cytokine receptors have taken on an expanding role in the treatment of chronic immune mediated diseases. Progressive multifocal leukoencephalopathy (PML) is a rare central neurological disease caused by JC virus infection that has been described in the setting of conditions with severe impairment of immune surveillance, such as haematological malignancies, stem cell or solid organ transplantation and AIDS. This serious demyelinating disease has recently been described in patients receiving monoclonal antibodies for chronic inflammatory diseases such as multiple sclerosis, Crohn's disease, rheumatoid arthritis, systemic lupus erythematosus or psoriasis. We review here the disease of PML, the different biological agents used in chronic inflammatory diseases that are associated with an increased risk of PML (natalizumab, rituximab, efalizumab and alemtuzumab), and the potential mechanisms that may explain the development of PML. Based on current knowledge of the biology of the JC virus and on the mechanisms of action of these biological agents, we discuss currently available tools that may be helpful in evaluating the risk of PML in this patient population.

Clinical aspects: focusing on key unique organ-specific issues of renal transplantation.

Kidney transplantation is the treatment of choice for patients with end-stage renal disease because of improved patient survival and quality of life as compared with dialysis. Successful transplantation requires the prompt recognition and appropriate management of both the immediate posttransplant surgical and medical complications as well as subsequent issues like recurrent disease and chronic rejection that affect long-term graft survival. Guidelines for understanding and managing some of the more important early and late kidney-specific transplant problems, including urologic complications, delayed graft function, acute and chronic rejection, BK polyoma virus infection, and recurrent glomerular disease, are reviewed.

Immunosuppressive agents as risk factors for BK virus nephropathy: an overview and update.

IMPORTANCE OF THE FIELD: BK virus has emerged as an important cause of graft dysfunction and failure in renal transplant recipients. Risk factors for BK virus nephropathy (BKN) are not well established, but evidence suggests that it is the result of a complex interplay between multiple donor- and recipient-related factors. AREAS COVERED IN THIS REVIEW: The purpose of this article is to review the current understanding on the effect of various immunosuppressive agents on BK viral replication and the results of different reported immunosuppression reduction protocols. WHAT THE READER WILL GAIN: The intensity of overall immunosuppression has been accepted as a major risk factor for the development of BKN. We review the data regarding the contribution of different anti-rejection agents to the risk of BK virus-induced graft injury. TAKE HOME MESSAGE: Although reduction in immunosuppression on detection of BK viral replication appears to be the most successful means in preserving allograft function, data are emerging that support the stronger association of the disease with tacrolimus, in contrast to mycophenolate compounds. Therefore, initial dose reduction for tacrolimus may be more beneficial than this anti-metabolite preemptively or after diagnosis of BKN.

Maintenance immunosuppressive agents as risk factors for BK virus nephropathy: a case-control study.

BACKGROUND: The specific role of different immunosuppressive agents as risk factors for BK virus nephropathy (BKN) has not been well studied. METHODS: In this case-control study, we examined the association of tacrolimus (TAC), mycophenolate mofetil (MMF), and prednisone with BKN in renal allograft recipients transplanted between 1997 and 2004 at our center who underwent biopsies for allograft dysfunction. Drug levels or doses were recorded during the 3 months before the index biopsy. Random effects logistic modeling was used for data analysis. RESULTS: There were 33 cases with BKN, biopsied at 16.4+/-2.8 months and 66 matched controls with biopsies at 21.5+/-2.1 months posttransplant (P=0.16). After adjusting for sex, race, retransplant status, diabetes, donor source, and induction agent, TAC blood level was associated with increased risk of BKN (odds ratio [OR] 1.3, 95% confidence interval [CI] 1.02-1.7, P=0.03), whereas MMF dose was not (OR 1.0, 95% CI 0.99-1.0, P=0.2). Moreover, prednisone dose was also found to be a significant risk factor for BKN (OR 1.22, 95% CI 1.04-1.4, P=0.02). CONCLUSIONS: The results of this study show that BKN is associated with TAC level and prednisone dose and not with MMF dose. This suggests that reducing TAC and prednisone dose and maintaining MMF may be a more appropriate initial approach for the treatment of BKN. Further studies are needed to compare the efficacy and safety of this approach with the currently recommended one.

Progressive multifocal leukoencephalopathy in a patient with B-cell lymphoma during rituximab-containing chemotherapy: case report and review of the literature.

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by the JC polyomavirus. We describe a rare case of PML in a 48-year-old female patient with diffuse large B-cell lymphoma who received rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) therapy. While she was undergoing five cycles of R-CHOP, she noticed gradually progressive neurological symptoms, such as slurred speech and gait disturbance, and she eventually developed high-grade fever. She also developed Pneumocystis jiroveci pneumonia. The neurological symptoms deteriorated thereafter, and she developed spastic quadriparesis and bulbar palsy. Magnetic resonance imaging showed hyperintensity within the right cerebellar hemisphere on T2-weighted images. Polymerase chain reaction-based tests of the cerebrospinal fluid revealed the presence of the JC virus. Despite intravenous and intrathecal cytarabine treatment, the patient died of PML 5 months after it was diagnosed. Retrospective analysis of her laboratory data showed that her CD4(+) T-cell count before R-CHOP therapy had decreased to 68 microL(-1). Thus, when administering rituximab-containing chemotherapy, even to patients with no prior history of opportunistic infections, attention should be paid to the potential occurrence of PML, particularly in patients with low CD4(+) T-cell counts.

SV40 infection associated with rituximab treatment after kidney transplantation in nonhuman primates.

BACKGROUND: A regimen consisting of polyclonal anti-T-cell antibody, sirolimus (SRL), and donor bone marrow (DBM) infusion induces robust transplantation tolerance to skin allografts in mice. We investigated the effect of a similar regimen in a nonhuman primate (NHP) model. METHODS: Cynomolgus macaques (Macaca fascicularis) were transplanted with mismatched kidney allografts. Recipients were treated with 7 doses of antithymocyte globulin (Thymoglobulin, day 1 to 9), sirolimus, and DBM infusion (day 14). Anti-CD20 antibody, rituximab, was given on days 0 and 5. RESULTS: A regimen of Thymoglobulin, 30 days of SRL, and DBM infusion induced significantly greater prolongation of graft survival with a mean survival time of 88 days compared with the control regimen (no DBM) with an mean survival time of 53 days (P=0.022). Unlike the murine skin allograft model, all grafts were rejected within 111 days. A combination of Thymoglobulin, continuous SRL, and rituximab caused graft and systemic SV40 infection and failed to achieve further extension of graft survival. C4d deposition was observed in 50% of recipients as early as 18 days, suggesting antidonor antibody production. A transient, low-to-moderate degrees of multilineage chimerism was observed after DBM infusion. Treatment with Thymoglobulin resulted in profound depletion of CD4+ and CD8+ T cells, whereas addition of rituximab achieved prolonged (up to 3 months) depletion of CD20+ B cells. CONCLUSION: The Thymoglobulin, SRL, and DBM protocol is simple and produces long-term kidney allograft survival in NHP although additional treatment modalities may be necessary for induction of long-term tolerance.