Co-infection of Polyomavirus-BK and Cytomegalovirus in Renal Transplant Recipients

A novel histologic index for polyomavirus nephropathy in comparison with the Banff scoring system: Clinical validation, prognostic implication, and correlation with plasma viral load

BK Polyomavirus nephropathy (PVN) with definitive diagnosis on biopsy, presents incidentally or with varying degrees of graft dysfunction. Banff working group on PVN has proposed a novel scoring system in renal biopsies, to identify patients with higher risk of graft failure. In this study, we attempted to validate the Banff scoring system at index biopsies and correlate with a novel index score, plasma BK-virus load and graft outcome. 48 patients with index biopsies of PVN diagnosed from 2019 to 2022, with simultaneous plasma BKV-virus loads and SV-40 stains were chosen. Biopsies were scored for Banff PVN Class and by novel PVN index. Inter-observer reproducibility was tested between 3 renal pathologists for all parameters and findings were correlated with graft outcome, in a median follow-up of 42 months. Banff PVN classes 2 and 3 and novel index 3 were associated with higher percentage of graft failure and persistent viremia. The novel index score showed a stronger and consistent temporal association with plasma BK-virus levels. Kappa scores revealed a 68 % agreement for Banff PVN class scoring. Our study highlights the prognostic utility of Banff PVN scheme and novel PVN index in correlation with plasma BKV viremia and graft outcome.

The simultaneous presence of active BK, Epstein Barr, and human cytomegalovirus infection and their correlation by host factors in patients suspected of kidney transplant rejection

AIMS

This study aims to evaluate the presence of EBV, HCMV, and BKV genomic sequences in the plasma samples (active infection/viremia) of kidney transplant recipients suspected of rejection and to investigate host and risk factors related to the activation of these viruses in these patients.

METHODS

In this cross-sectional single-center study, plasma samples were collected from 98 suspected kidney transplant rejection patients at Labafinejad Hospital, Tehran, Iran, between December 2022 and June 2023. Quantitative real-time PCR assays for HCMV, EBV, and BK were performed using GeneProof Real-time PCR kits. ROC curve analysis was used to determine the viral load cutoff point for each virus.

FINDINGS

HCMV active viremia was detected in 18 (18.36%) recipients, EBV active viremia in 7 (7.14%), and BKV active viremia in 5 (5.10%). ROC results indicated viral load cutoff points of 778, 661, and 457 points for HCMV, EBV, and BKV, respectively. The duration of time after transplantation significantly differed between active viremia and no viremia groups (120.5 vs. 46 months, P = 0.014). In the BKV active viremia group, the increase in creatinine compared to baseline creatinine was significantly higher than in the no viremia group (2.7 vs. 0.8, P = 0.017). The odds ratio of HCMV active viremia in patients taking tacrolimus was 2.84 times higher, and the odds of HCMV active viremia in patients taking antithymocyte globulin was 3.01 times higher than in patients not taking these drugs.

CONCLUSION

Rapid and timely diagnosis of viral active infections in kidney transplant patients is crucial for effective disease management and implementation of appropriate treatment strategies. Identifying potential risk factors, including host and treatment-related factors that influence transplantation, can facilitate the development of suitable preventive strategies.

The Second International Consensus Guidelines on the Management of BK Polyomavirus in Kidney Transplantation

BK polyomavirus (BKPyV) remains a significant challenge after kidney transplantation. International experts reviewed current evidence and updated recommendations according to Grading of Recommendations, Assessment, Development, and Evaluations (GRADE). Risk factors for BKPyV-DNAemia and biopsy-proven BKPyV-nephropathy include recipient older age, male sex, donor BKPyV-viruria, BKPyV-seropositive donor/-seronegative recipient, tacrolimus, acute rejection, and higher steroid exposure. To facilitate early intervention with limited allograft damage, all kidney transplant recipients should be screened monthly for plasma BKPyV-DNAemia loads until month 9, then every 3 mo until 2 y posttransplant (3 y for children). In resource-limited settings, urine cytology screening at similar time points can exclude BKPyV-nephropathy, and testing for plasma BKPyV-DNAemia when decoy cells are detectable. For patients with BKPyV-DNAemia loads persisting >1000 copies/mL, or exceeding 10 000 copies/mL (or equivalent), or with biopsy-proven BKPyV-nephropathy, immunosuppression should be reduced according to predefined steps targeting antiproliferative drugs, calcineurin inhibitors, or both. In adults without graft dysfunction, kidney allograft biopsy is not required unless the immunological risk is high. For children with persisting BKPyV-DNAemia, allograft biopsy may be considered even without graft dysfunction. Allograft biopsies should be interpreted in the context of all clinical and laboratory findings, including plasma BKPyV-DNAemia. Immunohistochemistry is preferred for diagnosing biopsy-proven BKPyV-nephropathy. Routine screening using the proposed strategies is cost-effective, improves clinical outcomes and quality of life. Kidney retransplantation subsequent to BKPyV-nephropathy is feasible in otherwise eligible recipients if BKPyV-DNAemia is undetectable; routine graft nephrectomy is not recommended. Current studies do not support the usage of leflunomide, cidofovir, quinolones, or IVIGs. Patients considered for experimental treatments (antivirals, vaccines, neutralizing antibodies, and adoptive T cells) should be enrolled in clinical trials.

Proteome Analysis for Inflammation Related to Acute and Convalescent Infection

Infectious diseases are a significant burden in global healthcare. Pathogens engage with different host defense mechanisms. However, it is currently unknown if there are disease-specific immune signatures and/or if different pathogens elicit common immune-associated molecular entities to common therapeutic interventions. We studied patients enrolled through the Human Immunology Project Consortium (HIPC), which focuses on immune responses to various infections. Blood samples were collected and analyzed from patients during infection and follow-up time points at the convalescent stage. The study included samples from patients with Lyme disease (LD), tuberculosis (TB), malaria (MLA), dengue virus (DENV), and West Nile virus (WNV), as well as kidney transplant patients with cytomegalovirus (CMV) and polyomavirus (BKV) infections. Using an antibody-based assay, we quantified ~ 350 cell surface markers, cytokines, and chemokines involved in inflammation and immunity. Unique protein signatures were identified specific to the acute phase of infection irrespective of the pathogen type, with significant changes during convalescence. In addition, tumor necrosis factor receptor superfamily member 6 (TNR6), C-C Motif Chemokine Receptor 7 (CCR7), and C-C motif chemokine ligand-1 (CCL1) were increased in the acute and convalescent phases across all viral, bacterial, and protozoan compared to blood from healthy donors. Furthermore, despite the differences between pathogens, proteins were enriched in common biological pathways such as cell surface receptor signaling pathway and response to external stimulus. In conclusion, we demonstrated that irrespective of the pathogen type, there are common immunoregulatory and proinflammatory signals.

Concomitant Polyoma BK Virus and West Nile Virus in Renal Allografts

Surveillance of the renal allograft recipient is essential when monitoring renal function to detect the early onset of rejection and alter therapeutic treatments to treat acute rejection or other causes and improve long-term graft function. If renal function begins to deteriorate, a renal biopsy is often indicated to assess the Banff grade of potential rejection or other causes, especially in the setting of polyoma BK viral load elevation. Although BK infection in the allograft is asymptomatic, reactivation of the virus is known to be associated with the acceleration of pathologic change and a poor outcome in the allograft. BK reactivation in a transplant kidney is not uncommon, and determining inflammation related to the virus versus acute rejection is paramount for appropriate immunosuppressive therapy management. We identified a concomitant polyoma BK virus and West Nile Virus (WNV) infection in two renal transplant patients which, to our knowledge, has not previously been reported. However, other concomitant infections have been reported in renal allografts including BK virus and cytomegalovirus (CMV), CMV and hepatitis C (HCV), and HCV and human immunodeficiency virus (HIV). As WNV has become endemic in many regions of the United States, and since the transmission of the virus via transplanted organs is associated with significant morbidity and mortality, it may be prudent to consider serologic screening for WNV in living donors prior to organ procurement. Regardless, the observation we made and report here should underscore the potential for concomitant viral infections that may be masked when a renal allograft has a significant inflammatory response to BK virus.

Risk Factors for CMV and BK Infections in an Elderly Veteran Population Following Kidney Transplantation: Implications for Immunosuppression Induction and Management

Cytomegalovirus (CMV) and BK Polyomavirus (BKPyV) are the most common opportunistic pathogens following kidney transplantation. We evaluated 102 patients with a median age of 63 at Edward Hines VA Hospital from November 2020 to December 2022. Our primary interest was the incidence of CMV and BKPyV infections, as well as CMV and BKPyV coinfection. Secondary interests included time to infection, rejection, and graft and patient survival. There were no statistically significant differences in patient age, donor age, race, transplant type, incidence of delayed graft function, or induction in both cohorts (any infection (N = 46) vs. those without (N = 56)). There was a 36% (37/102) incidence of CMV, a 17.6% (18/102) of BKPyV and an 8.8% (9/102) incidence of coinfection. There was a decreased incidence of CMV infection in Basiliximab induction versus antithymocyte globulin (21% and 43%). CMV risk status had no effect on the incidence of CMV infection following transplant. African American recipients had a lower incidence of BKPyV infection (12% vs. 39%), yet a higher incidence was observed in those with high cPRA (50% vs. 14%). Most CMV and/or BKPyV infections occurred within the first six months post-transplant (54%). Immunosuppression management of the elderly should continually be evaluated to reduce opportunistic infections post-transplant.

Importance of Follow-Up Biopsies in the Prediction of Renal Allograft Survival Following Polyomavirus-Associated Nephropathy

OBJECTIVES

Allograft biopsy is the gold standard for diagnosing polyomavirus-associated nephropathy. We aimed to establish the effects of histopathologic findings proposed by the Banff Polyomavirus Working Group on graft outcome. We also aimed to understand the clinical importance of follow-up biopsies for patients with polyomavirus-associated nephropathy.

MATERIALS AND METHODS

Our study included 22 patients with polyomavirus-associated nephropathy. All biopsies were classified according to the latest Banff Polyomavirus Working Group classification. Follow-up biopsies of all patients were evaluated in detail.

RESULTS

The mean interval between polyomavirus-associated nephropathy and transplant was 10 ± 1.6 months. Of 22 patients, biopsy revealed stage 1 in 3 (13.6%), stage 2 in 17 (77.3%), and stage 3 in 2 patients (9.1%). Fourteen patients (63.6%) had polyomavirus viral load 3, 5 (22.7%) had polyomavirus viral load 2, and 3 had polyomavirus viral load 1. Among patients included in analyses, 18.2% had antibody-mediated rejection and 27.2% had T-cell-mediated rejection simultaneously with polyomavirus-associated nephropathy. Graft loss increased with increasing polyomavirus-associated nephropathy class and polyomavirus viral load (P = .015 and P = .002, respectively). The mean time of graft survival decreased with increasing degree of tubulitis, interstitial inflammation, plasma infiltration, and neutrophil infiltration. Patients with interstitial fibrosis, glomerular polyoma, and cortical plus medullar involvement showed earlier graft loss. Follow-up biopsies showed that diffuse interstitial fibrosis or persistent inflam-mation negatively influenced graft loss.

CONCLUSIONS

The Banff Polyomavirus Working Group's schema significantly correlated with graft outcome. Early detection of polyomavirus-associated nephro-pathy and subsequent detection of persistent inflammation and interstitial fibrosis and tubular atrophy in follow-up biopsies and modification of immunosuppressive therapy can successfully prevent graft loss.

Risk factors and outcome of concurrent and sequential multiviral cytomegalovirus, Epstein-Barr virus, BK virus, adenovirus and other viral reactivations in transplantation

PURPOSE OF REVIEW

Reactivation of viral infections occurs frequently in immunosuppressed populations, particularly in solid organ (SOT) or allogeneic haematopoietic cell (HCT) transplant patients. Concurrent and sequential multivirus infections are common, yet risk factors and outcomes remain unclear. This review aims to identify the patients vulnerable to multivirus infections and characterize the impact of increased viral burden to formulate prevention and treatment strategies.

RECENT FINDINGS

Incidences of up to 89% in SOT and 36% in HCT have been reported for two viruses, and 32% in SOT and 28% in HCT for at least three viruses. Risk factors appear related to an increased burden of immunosuppression, with most viral coinfections occurring within 12 months of transplantation. Direct viral complications such as cytomegalovirus disease are more frequent in coinfected patients, with documented prolonged duration of viraemia, higher viral load and increased end-organ disease. Graft dysfunction, acute rejection and graft-vs.-host disease (GVHD) have also been associated. Increased mortality is reported in the HCT population.

SUMMARY

Multivirus infections occur in a significant proportion of transplant patients and is linked to immunosuppressive burden. There is increasing evidence that this leads to worse graft and patient outcomes. Further prospective studies are required to further comprehensively characterise viral epidemiology, mechanisms and treatment strategies to ameliorate this risk.

Viral-specific cytotoxic T-cell responses in HLA-sensitized kidney transplant patients maintained on everolimus and low dose tacrolimus

BACKGROUND

Maintenance with "everolimus + reduced dose tacrolimus" (Ev + Tac_low ) was reported to reduce the risk of viral infections compared to (Tac + MMF). Here we examined viremia and viral-specific T-cell (viral-Tc) responses in patients treated with Ev + Tac_low v. Tac + MMF in highly-HLA sensitized patients.

METHODS

HLA sensitized (HS) kidney transplant patients were monitored pre- and post-transplant for viremia (CMV, BK and EBV) by PCR in 19 Ev + Tac_low and 48 Tac + MMF patients. For CMV PCR analysis, we compared infection rates in 19 Ev + Tac_low patients to 48 CMV D+/R- (#28) or CMV D-/R- (#20) Tac + MMF patients. CMV-Tc and EBV-Tc were evaluated by cytokine flow cytometry, and DSA levels by Luminex for selected patients in both groups.

RESULTS

CMV, EBV viremia rates were similar in Ev + Tac_low v. Tac + MMF patients, but BKV rates were significantly higher in Ev + Tac_low patients. No patient in either group developed BKAN or PTLD. CMV- & EBV-Tc decreased significantly after alemtuzumab induction but returned to pre-treatment levels 1-2 months post-transplant in most patients. de novo DSA was similar in both groups as were patient and graft survival and graft rejection.

CONCLUSIONS

CMV-Tc, EBV-Tc were similar in Ev + Tac_low and Tac + MMF patients. EBV and CMV viremia rates were similar over 1 year. BKV rates were significantly higher in Ev + Tac_low patients suggesting no benefit for Ev + Tac_low in enhancing viral specific Tc effector functions or limiting viral infections. This article is protected by copyright. All rights reserved.

BK Virus and Cytomegalovirus Coinfections in Kidney Transplantation and Their Impact on Allograft Loss

We aimed to ascertain the interaction and effects of combined reactivations of BK virus and cytomegalovirus on kidney graft function. All consecutive kidney transplant recipients (KTR) between 2003 and 2016 were included. Of 1976 patients who received a kidney transplant, 23 (1.2%) presented BKV-associated nephropathy (BKVAN). Factors independently associated with BKVAN were diabetes mellitus (odds ratios (OR) 3.895%, confidence intervals (CI) (1.4-10.5)), acute allograft rejection (OR 2.8 95%, CI (1.1-7.6)) and nephrostomy requirement (OR 4.195%, CI (1.3-13)). Cytomegalovirus infection was diagnosed in 19% of KTR patients. Recipients with BKVAN presented more frequently with cytomegalovirus (CMV) infection compared to patients without BKVAN (39% vs. 19%, p = 0.02). Acute allograft rejection (OR 2.95%, CI (1.4-2.4)) and nephrostomy requirement (OR 2.95%, CI (1.2-3)) were independently associated with CMV infection. Sixteen patients (69%) with BKVAN had graft dysfunction at one-year post-transplant and eight of them (35%) lost their graft. Patients presenting with BKVAN and graft loss presented more frequently a cytomegalovirus infection (OR 2.295%, CI (1.3-4.3)). In conclusion, we found a relation between CMV infection and graft loss in patients presenting BKVAN, suggesting that patients with CMV reactivation should be actively screened for BKV.

Significance of BK Polyomavirus in Long-Term Survivors after Adult Allogeneic Stem Cell Transplantation

Simple Summary

Allogeneic stem cell transplantation is a curative treatment option for several hematological diseases. Data about health status and late complications of long-term survivors of this therapy are limited, so we conducted a prospective study. This analysis focusses on kidney function and urological complications. Interestingly, the BK polyomavirus plays an important role in this patient population and can lead to severe impairment of kidney function. This was only previously described in the acute situation following transplantation. Further studies should address causal therapy development for this severe viral infection.

Abstract

Background: Allogeneic stem cell transplantation (aSCT) is a common treatment for a variety of hematological diseases. Advances in transplantation practices have led to an increasing number of long-term aSCT survivors, but data about health status and late complications are sparse. This analysis focusses on kidney function and urological complications in this population. Methods: This study is a prospective unicentric non-interventional trial. Before starting the study, we obtained the approval of the local ethics review board. Furthermore, the study was registered at WHO Clinical Trial Registry. The study protocol is available via UTN. Results: We were able to include 33 patients with a mean age of 60.5 years (SD 11.1). The median survival time following allogeneic stem cell transplantation was 9.0 years (IQR 8.5–13.0). Five patients (15.2%) had BKPyV viruria with mean 218.3 (SD 674.2) copies/mL. BKPyV viruria was significantly linked to pre-existing chronic kidney failure (p = 0.019), creatine > 100 µmol/L (p < 0.001), and cystatin c > 1.11 mg/L (p = 0.021), respectively. We were not able to identify a single risk factor for BKPyV viruria in univariate or multivariate Cox regression. Conclusions: BKPyV-associated nephropathy might be one reason for impaired kidney function in long-term survivors of aSCT.

Clinical features of BK-polyomavirus and cytomegalovirus co-infection after kidney transplantation

BK polyomavirus (BKPyV) and cytomegalovirus (CMV) are the main viral pathogens affecting the graft and recipient outcome after allogenic kidney transplantation. It has recently been found that infection with both viruses has a greater impact on kidney graft function than a single infection. We retrospectively analyzed a cohort of 723 recipients who received kidney transplantation between 2007 and 2015 after living and postmortal donation for differences in risk and outcome parameters regarding BKPyV (DNAemia) and CMV (CMV DNAemia) co-infection compared to sole viremias and to patients without viremia. Of all kidney allograft recipients in our cohort, 8.2% developed co-infection with BKPyV DNAemia and CMV DNAemia, 15.1% showed BKPyV viremia alone and 25.2% sole CMV DNAemia. Acute rejection was closely linked with co-infection (multivariable analysis, p = 0.001). Despite the fact that the estimated glomerular filtration rate of patients with co-infection was noticeably reduced compared to patients with BKV or CMV infection alone, transplant survival and patient survival were not significantly reduced. Co-infection with BKPyV and CMV in kidney transplanted patients is significantly associated with inferior allograft function. Since co-infection is strongly associated with acute rejection, co-infected individuals should be considered a risk collective.

Management of BK viremia is associated with a lower risk of subsequent cytomegalovirus infection in kidney transplant recipients

The risk of subsequent cytomegalovirus infection (CMV) in kidney transplant recipients (KTR) after diagnosis of BK polyomavirus viremia (BKV) is unclear, and current evidence is conflicting. We reviewed all KTR transplanted at our institution between 1/1/2005 and 12/31/2015. Follow-up began 3 months after transplantation to avoid confounding effects of prophylaxis. Clinically significant BKV, defined as detectable BK viremia >1000 copies/mL via molecular diagnostic testing (PCR), was treated as a time-varying exposure with 1-year follow-up. This viral load cutoff was chosen to ensure a more homogenous population that would be considered to have clinically significant BK viremia that necessitated management via immunosuppressive modification. Patients were then screened for subsequent CMV infection. 2435 RTX recipients met inclusion criteria; of these, 314 developed BKV during follow-up (BK+). Lymphocyte depletion, tacrolimus maintenance, and biopsy-proven rejection were significantly higher in the BK+ group. BK+ was associated with lower risk of subsequent CMV infection (BK+ HR 0.45, 95% CI 0.22-0.94, P = .03, relative risk reduction 55%). When adjusted for significant confounding factors, CMV incidence remained reduced in the BK+ population (HR 0.47, 95% CI 0.22-0.98, P = .04). This large series of KTR demonstrates that BKV is associated with lower risk of subsequent CMV infection.

Cytomegalovirus prevention strategies and the risk of BK polyomavirus viremia and nephropathy

Polyomavirus BK (BKV) is the cause of polyomavirus-associated nephropathy resulting in premature graft loss. There are limited data regarding the role of cytomegalovirus (CMV) infection and its prevention in developing BKV viremia and PVAN. In a prospective study, we analyzed 207 consecutive renal transplant recipients previously enrolled in 2 randomized trials evaluating different CMV prevention regimens with routine screening for BKV and CMV. Of these, 59 received valganciclovir and 100 valacyclovir prophylaxis; 48 patients were managed by preemptive therapy. At 3 years, the incidence of BKV viremia and PVAN was 28% and 5%, respectively. CMV DNAemia developed in 55% and CMV disease in 6%. Both BKV viremia (42% vs 23% vs 21%, P = .006) and PVAN (12% vs 2% vs 2%, P = .011) were increased in patients treated with valganciclovir prophylaxis compared to valacyclovir and preemptive therapy. Using multivariate Cox proportional hazard regression, valganciclovir prophylaxis was independent predictor of BKV viremia (hazard ratio [HR] = 2.38, P = .002) and PVAN (HR = 4.73, P = .026). In contrast, the risk of subsequent BKV viremia was lower in patients with antecedent CMV DNAemia (HR = 0.50, P = .018). These data suggest valganciclovir prophylaxis may be associated with increased risk of BKV viremia and PVAN. CMV DNAemia did not represent a risk for BKV.

Cytomegalovirus and Epstein-Barr virus infections among pediatric kidney transplant recipients at a center using universal Valganciclovir Prophylaxis

BACKGROUND

CMV is associated with adverse effects in renal transplant recipients. The objective of this study was to characterize the incidence and timing of CMV and EBV infections in relation to valGCV prophylaxis in a pediatric renal transplant cohort.

METHODS

Retrospective cohort of pediatric renal transplant patients given universal valGCV prophylaxis and universal viral surveillance was evaluated. Demographics, prophylaxis, acute rejection, and CMV and EBV infections were abstracted.

RESULTS

A total of 92 pediatric renal allograft recipients, 2008-2013, were included. One or more viral infections developed in 77/92 (83.7%) of the patients. EBV was the most common in 62/92 (67%) patients, irrespective of valGCV (82% of episodes occurring on valGCV). CMV DNAemia occurred in 30/92 (33%) patients, 14 episodes (47%) occurring on valGCV. Incidence of breakthrough CMV on prophylaxis was 15% and was associated with persistent DNAemia (OR 7.8, CI:1.6-32.9, P < 0.02). CMV tissue-invasive disease was not seen. CMV syndrome occurred in 10% of the cohort, only in CMV D+ patients, and only one symptomatic breakthrough infection required treatment. Out of 92, 21 (23%) had simultaneous co-infections with 2-3 viruses.

CONCLUSIONS

Viral infections in pediatric renal transplant recipients receiving universal valGCV prophylaxis were common. EBV infections were not reduced by valGCV prophylaxis, and nearly half of CMV infections occurred on valGCV. Symptomatic CMV infection while on prophylaxis was rare. valGCV prophylaxis may prevent symptomatic CMV infection but not EBV infection, and frequent CMV surveillance in pediatric renal transplant recipients on prophylaxis may not be necessary.

BKV, CMV, and EBV Interactions and their Effect on Graft Function One Year Post-Renal Transplantation: Results from a Large Multi-Centre Study

Background

BK virus (BKV), Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) reactivations are common after kidney transplantation and associated with increased morbidity and mortality. Although CMV might be a risk factor for BKV and EBV, the effects of combined reactivations remain unknown. The purpose of this study is to ascertain the interaction and effects on graft function of these reactivations.

Methods

3715 serum samples from 540 kidney transplant recipients were analysed for viral load by qPCR. Measurements were performed throughout eight visits during the first post-transplantation year. Clinical characteristics, including graft function (GFR), were collected in parallel.

Findings

BKV had the highest prevalence and viral loads. BKV or CMV viral loads over 10,000 copies·mL⁻¹ led to significant GFR impairment. 57 patients had BKV-CMV combined reactivation, both reactivations were significantly associated (p = 0.005). Combined reactivation was associated with a significant GFR reduction one year post-transplantation of 11.7 mL·min⁻¹·1.73 m⁻² (p = 0.02) at relatively low thresholds (BKV > 1000 and CMV > 4000 copies·mL⁻¹). For EBV, a significant association was found with CMV reactivation (p = 0.02), but no GFR reduction was found. Long cold ischaemia times were a further risk factor for high CMV load.

Interpretation

BKV-CMV combined reactivation has a deep impact on renal function one year post-transplantation and therefore most likely on long-term allograft function, even at low viral loads. Frequent viral monitoring and subsequent interventions for low BKV and/or CMV viraemia levels and/or long cold ischaemia time are recommended.

Fund

Investigator Initiated Trial; financial support by German Federal Ministry of Education and Research (BMBF).

Development and validation of multiplex real-time PCR assays for rapid detection of cytomegalovirus, Epstein-Barr virus, and polyomavirus BK in whole blood from transplant candidates

Transplant recipients are more susceptible to bacterial and viral infections. Cytomegalovirus (CMV), Epstein-Barr virus (EBV), and polyomavirus BK (BK) are risk factors for graft dysfunction. All three of them are latent viruses that can cause serious disease in immunocompromised patients. Mainly qualitative PCR tests are required for diagnosis and quantitative monitoring, which are used to follow the response to transplantation. We developed a multiplex real-time PCR (qPCR) method to detect these viruses during blood screenings of transplant recipients. We also validated analytical and clinical performance tests using the developed multiplex qPCR. The limit of detection (LOD) was 100, 125, and 183 copies/ml for CMV, EBV, and BK, respectively. These results had high linearity (R² = 0.997) and reproducibility (CV range, 0.95-2.38%, 0.52-3.32%, and 0.31-2.45%, respectively). Among 183 samples, we detected 8 samples that were positive for CMV, while only 6 were positive for EBV, and 3 were positive for BK. Therefore, the viral infection prevalence in transplant candidates was 4.40% for CMV, 3.29% for EBV, and 1.64% for BK. This multiplex qPCR method should be used widely for diagnosing and monitoring latent viral infections in transplant recipients.

BK viremia is not associated with adverse outcomes in the absence of BK nephropathy

There are limited data regarding the association of different levels of BK viremia and BK nephropathy (BKN), and graft outcomes. We studied the BK plasma PCR levels of all kidney transplant recipients (KTR) transplanted at our institution between 01/01/2006 and 06/30/2014. Patients were divided into groups based on their highest BK plasma PCR level within the first year following transplantation: undetectable, low (<1000 copies/mL), moderate (1000-10 000 copies/mL), high (>10 000-100 000 copies/mL), very high (>100 000 copies/mL), and those that had biopsy-proven BKN. There were a total of 1146 KTR during the study period: 813 with undetectable BK levels and 333 with any detectable BK level (87 with low, 79 with moderate, 88 with high, 34 with very high level BK, and 45 that had BKN). Compared to KTR with an undetectable BK level, incidence of mortality, graft failure, rejections,and infections were not significantly different for those with low, moderate, high, or very high BK level. Patients with BKN had a higher rate of infection and higher rates of total graft failure or death-censored graft failure compared to those with undetectable BK levels. BK viremia in the absence of BKN does not significantly increase the risk of rejection, infections, or graft failure compared to an undetectable BK level.

BK Virus-Associated Nephropathy: Current Situation in a Resource-Limited Country

BACKGROUND

Data on BK virus-associated nephropathy (BKVAN) and treatment strategy in a resource-limited country are scarce. This study aimed to evaluate epidemiology of BKVAN and its situation in Thailand.

METHODS

A retrospective analysis was conducted among adult kidney transplant recipients at Ramathibodi Hospital from October 2011 to September 2016. Patients' demographic data, information on kidney transplantation, immunosuppressive therapy, cytomegalovirus and BK virus infections, and allograft outcomes were retrieved and analyzed.

RESULTS

This study included 623 kidney transplant recipients. Only 327 patients (52.49%) received BK virus infection screening, and 176 of 327 patients had allograft dysfunction as a trigger for screening. BKVAN was identified in 39 of 327 patients (11.93%). Deceased donor transplantation and cytomegalovirus infection were associated with a higher risk of BKVAN (odds ratio = 2.2, P = .024, 95% confidence intervals [1.1, 4.43], and odds ratio = 2.6, P = .006, 95% confidence intervals [1.29, 5.26], respectively). BKVAN patients were at significantly higher risk for allograft rejection (P < .001) and allograft failure (P = .036). At the end of the study, 4 graft losses were documented (12.12%).

CONCLUSIONS

BKVAN was associated with high rate of allograft rejection and failure. However, surveillance of its complications has been underperformed at our facility. Implementing a formal practice guideline may improve allograft outcome in resource-limited countries.

BK Virus: A Cause for Concern in Thoracic Transplantation?

Human BK polyomavirus (BKV) infection is poorly documented in heart and lung transplant patients. BK viruria and viremia have been estimated to affect 19% and 5% of heart transplant recipients, respectively. Data are limited, especially for lung transplantation, but the proportion of patients progressing from BK viruria to viremia or BKV-related nephropathy (BKVN) appears lower than in kidney transplantation. Nevertheless, a number of cases of BKVN have been reported in heart and lung transplant patients, typically with late diagnosis and generally poor outcomes. Risk factors for BKV infection or BKVN in this setting are unclear but may include cytomegalovirus infection and anti-rejection treatment. The relative infrequency of BKVN or other BK-related complications means that routine BKV surveillance in thoracic transplantation is not warranted, but a diagnostic workup for BKV infection may be justified for progressive renal dysfunction with no readily-identifiable cause; after anti-rejection therapy; and for renal dysfunction in patients with cytomegalovirus infection or hypogammaglobulinemia. Treatment strategies in heart or lung transplant recipients rely on protocols developed in kidney transplantation, with reductions in immunosuppression tailored to match the higher risk status of thoracic transplant patients.

Are the Polyomaviruses BK and JC Associated with Opportunistic Infections, Graft-versus-Host Disease, or Worse Outcomes in Adult Patients Receiving Their First Allogeneic Stem Cell Transplantation with Low-Dose Alemtuzumab?

BACKGROUND

The association of polyomaviruses BK and JC with other opportunistic infections and graft-versus-host disease (GvHD) in allogeneic stem cell transplantation is controversially discussed.

METHODS

We conducted a retrospective study of 64 adult patients who received their first allogeneic stem cell transplantation between March 2010 and December 2014; the follow-up time was 2 years.

RESULTS

Acute leukemia was the most frequent underlying disease (45.3%), and conditioning included myeloablative (67.2%) and nonmyeloablative protocols (32.8%). All patients received 10 mg of alemtuzumab on day -2 (20 mg in case of mismatch) as GvHD prophylaxis. Twenty-seven patients (41.5%) developed cytomegalovirus (CMV) reactivation. BKPyV-associated hemorrhagic cystitis was diagnosed in 10 patients (15.6%). Other opportunistic infections caused by viruses or protozoa occurred rarely (<10%). There was no association of BKPyV or JCPyV with CMV reactivation, Epstein-Barr virus reactivation, human herpes virus 6, or parvovirus B19 infection requiring treatment. There was a significant correlation of BKPyV-associated hemorrhagic cystitis with toxoplasmosis (p = 0.013). Additionally, there was a significant link of simultaneous BKPyV and JCPyV viruria with toxoplasmosis (p = 0.047). BKPyV and JCPyV were not associated with GvHD, relapse, or death.

CONCLUSION

We found no association of BKPyV or JCPyV with viral infections or GvHD. Only the correlation of both polyomaviruses with toxoplasmosis was significant. This is a novel and interesting finding.

Incidence, risk factors and the effect of polyomavirus infection in hematopoietic stem cell transplant recipients

Objective The effect of polyomavirus infection in HSCT recipients is poorly understood. Methods We evaluated 38 HSCT recipients. Polyomavirus was detected by nested qualitative polymerase chain reaction (PCR) assays of urine. The risk factors for BK virus and JC virus were analysed. The kidney and liver functions of infected and uninfected patients were compared. Results BK virus, JC virus, and simian virus 40 were detected in 21%, 42%, and 0% of HSCT recipients respectively. HCMV infection was found to be an independent risk factor for JC virus infection (odds ratio (OR): 8.528), while transplants with mismatched HLA are more susceptible to BK virus infection (OR: 12.000). Liver function of JC virus-infected subjects was worse than that of uninfected subjects. Conclusion We must be vigilant for opportunistic polyomavirus infections in HSCT recipients, especially those with HCMV co-infection or a mismatched HLA transplant. When unexplained liver function deterioration is observed, JC virus infection should be considered.

Impact of Desensitization on Antiviral Immunity in HLA-Sensitized Kidney Transplant Recipients

Viral infections represent significant morbidity and mortality factors in kidney transplant recipients, with CMV, EBV, and BKV infections being most common. Desensitization (DES) with IVIg and rituximab with/without plasma exchange followed by kidney transplantation with alemtuzumab induction increased successful transplant rates in HLA-sensitized patients but may represent an increased risk for viral infections due to severe lymphocyte depletion. Here, we report on the posttransplant viral infection status in 372 DES versus 538 non-DES patients. CMV and EBV viremia were significantly lower in DES patients, while BKV viremia was similar. This trend was observed primarily in CMV sero(-), EBV sero(+), and sero(-) patients. No patient developed PTLD. The incidence of BKAN, allograft, and patient survival was similar in both groups. These viral infections were not associated with subsequent allograft rejection which occurred within 6 months after the infection. Conclusions. The IVIg + rituximab desensitization combined with alemtuzumab induction with triple immunosuppression maintenance does not increase the risk for CMV, EBV, and BKV infections. Possible factors include, in addition to posttransplant antiviral prophylaxis and PCR monitoring, presence of memory T cells and antibodies specific to CMV and likely EBV, NK cell-mediated ADCC despite lymphocyte depletion, elimination of EBV and CMV reservoirs by rituximab and alemtuzumab, and use of IVIg with antiviral properties.

JC polyomavirus viremia and progressive multifocal leukoencephalopathy in human leukocyte antigen-sensitized kidney transplant recipients desensitized with intravenous immunoglobulin and rituximab

BACKGROUND

Desensitization (DES) with intravenous immunoglobulin (IVIG) + rituximab is effective, safe, and increases the transplantation rate in human leukocyte antigen-sensitized patients. However, reports of progressive multifocal leukoencephalopathy (PML) caused by JC polyomavirus (JCPyV) in autoimmune patients treated with rituximab is concerning. Here, we report on the JCPyV viremia and PML status in kidney transplant patients with/without DES (non-DES).

METHODS

In total 1195 and 699 DNA samples from plasma in 117 DES (78% lymphocyte-depleting [LyD] induction) and 100 non-DES patients (45% LyD), respectively, were submitted for JCPyV-polymerase chain reaction. Results were compared in both groups.

RESULTS

No patients in either DES or non-DES developed PML or presented with any neurological symptoms. The JCPyV viremia rate was similar in DES and non-DES patients (3/117 vs. 9/100, P = 0.07). The JCPyV levels were low (median peak levels, 1025 copies/mL) and JCPyV viremia was observed only once during the study period in most patients. All 3 DES patients with JCPyV(+) received 1 dose rituximab and no DES patients with >1 dose rituximab showed JCPyV(+). All 3 JCPyV(+) DES patients received LyD induction, while only 2 of 9 JCPyV(+) non-DES patients did so, and the remaining 7 received non-LyD or no induction. JCPyV in leukocyte was mostly negative in DES and non-DES patients. Immunosuppression in patients with or without JCPyV(+) was similar. BK polyomavirus viremia was observed more commonly in patients with JCPyV(+) than in those without (P < 0.02).

CONCLUSIONS

Patients with IVIG + rituximab DES followed by transplantation with LyD induction and additional rituximab rarely show JCPyV viremia and appear at low risk for PML.

Clinical significance of quantitative and qualitative detection of BK and JC virus in blood and urine of renal transplantation recipients

Objective:

To evaluate value of quantitative and qualitative detection of BK virus (BKV) and JC virus (JCV) in timely diagnosing polyomavirus-associated nephropathy (PVAN) occurring inrenal transplantation recipients.

Methods:

We collected 306 cases of urine specimen and 310 cases of blood specimen from 306 patients who underwent renal transplant. Levels of BKV and JCV in blood and urine were detected using real-time quantitative polymerase chain reaction (PCR).

Results:

Detection rate of BKV DNA was 33.3% (102/306) in urine and 34.8% (108/310); while that of JCV DNA was 30.7% (94/306) and 33.5% (104/310) respectively. The lowest detectable limit of BCK and JCV detection for patients who underwent renal transplant was 2×10³ copies/ml, suggesting high specificity and sensitivity.

Conclusion:

Real-time quantitative PCR is able to monitor BCV and JCV in renal transplant recipients in a convenient and rapid way, thus it is beneficial for early discovery, diagnosis and treatment of PVAN.

In Kidney Transplant Recipients With a Positive Virtual Crossmatch, High PRA was Associated With Lower Incidence of Viral Infections

BACKGROUND

There is little information on the incidence, risk factors, and outcomes associated with CMV and BK infections in sensitized patients.

METHODS

We examined 254 consecutive kidney transplant recipients with positive virtual crossmatch and negative flow crossmatch.

RESULTS

A total of 111 patients (43%) developed CMV disease or BK infection or nephropathy (BKVN). Specifically, 78 patients (30.7%) developed BK infection, 19 (7.5%) had BKVN, and 33 (12.9%) presented with CMV disease. Four patients (1.5%) developed both infections. Mean time from transplant to diagnosis for BK and CMV was 4.07 ± 3.10 and 8.35 ± 5.20 months, respectively. African American (HR, 2.64; 95% CI, 1.37-5.07; P = 0.003), thymoglobulin induction (HR, 2.18; 95% CI, 1.38-3.43; P = 0.0008), DSA greater than 500 MFI at transplant (HR, 1.64; 95% CI, 1.05-2.57; P = 0.03), history of diabetes (HR, 1.62; 95% CI, 1.01-2.60; P = 0.04), CMV D+/R- (HR, 2.30; 95% CI, 1.06-5.01; P = 0.03), and acute rejection (HR, 1.49; 95% CI, 0.99-2.24; P = 0.05) were associated with increase incident of BK/CMV, whereas rituximab (HR, 0.47; 95% CI, 0.24-0.91; P = 0.02), peak PRA greater than 80% (HR, 0.48; 95% CI, 0.27-0.84; P = 0.01), and living donor transplant (HR, 0.57; 95% CI, 0.36-0.87; P = 0.01) were associated with a lower likelihood of infection. Thymoglobulin induction (HR, 2.50; 95% CI, 1.02-6.13; P = 0.04), and peak PRA greater than 80% (HR, 0.45; 95% CI, 0.23-0.86; P = 0.02) remained significant predictors of infection after multivariate adjustment.

CONCLUSIONS

Although more than 40% of patients with a positive virtual crossmatch presented with BK infection/CMV disease, high PRA greater than 80% seemed to be protective.

CMV Viremia is associated with a decreased incidence of BKV reactivation after kidney and kidney-pancreas transplantation

BACKGROUND

Cytomegalovirus (CMV) and BK virus (BKV) infections can cause significant morbidity after kidney and kidney-pancreas transplant. There are limited data on the epidemiology and interactions between these two viral pathogens.

METHODS

We prospectively screened 609 kidney or kidney-pancreas transplant recipients from January 2007 to June 2011 for BKV and/or CMV viremia. This included 7453 quantitative BKV polymerase chain reaction and 15,496 quantitative CMV polymerase chain reaction tests. We evaluated risk factors and timing of these infections and the impact of treatment of one infection on the other.

RESULTS

Among 609 recipients, 108 (17.7%) developed CMV viremia, of which 95 (88%) were asymptomatic, 5 (5%) had CMV syndrome, and 8 (7%) developed CMV tissue invasive disease at a median of 5.6 months after transplantation. Risk factors for CMV infection using multivariable analysis were D+R- serogroup (P≤0.0001), donor age >50 years (P=0.013), and higher mean tacrolimus (P=0.0009) and mycophenolate mofetil (P=0.01) blood levels. The incidence of BKV infection in the total population was 163 of 609 (26.7%), of which 150 (92%) occurred in patents without antecedent CMV viremia. Such patients demonstrated a higher rate of subsequent BKV viremia than patients with antecedent CMV viremia (P=0.003; hazard ratio, 2.05; 95% confidence interval, 1.2-3.4). Moreover, we found that only symptomatic CMV viremia had a significant negative impact on graft survival when compared with asymptomatic CMV viremia and those without CMV viremia (relative risk, 3.5; 95% confidence interval, 1.06-8.9; P=0.04).

CONCLUSION

CMV viremia may indirectly protect against subsequent BK viremia possibly due to a reduction of intensity of immunosuppression after diagnosis of CMV viremia.

BK viremia and polyomavirus nephropathy in 352 kidney transplants; risk factors and potential role of mTOR inhibition

Background

Polyomavirus BK nephropathy (PyVAN) remains an important cause of early graft dysfunction and graft loss in kidney transplantation.

Methods

In this retrospective, single centre cohort study we studied the incidence and outcome of BK viral infection in 352 patients transplanted in 2008–2011.

Results

During follow-up viral replication was detected in 48 patients (13.6%); 22 patients (6.2%) had biopsy proven PyVAN.

In multivariate logistic regression analyses risk factors for BK-viremia were lack of enrolment into randomized controlled trials (RCTs), biopsy proven acute rejections, cytomegaly virus (CMV) serostatus of both donor and recipient and previous transplantation.

In patients without PyVAN reduction or switch of immunosuppression was associated with rapid viral clearance and stable graft function. In contrast, in most patients with PyVAN graft function deteriorated and 5 patients prematurely lost their allograft. Switch of immunosuppression to a low dose cyclosporine plus mTOR inhibitor based regimen in patients with PyVAN was safe, well tolerated and tended to be associated with a better short-term outcome in terms of graft function compared to reduction of existing immunosuppression alone.

Conclusions

With the lack of licensed anti-polyoma viral drugs reduction or conversion of immunosuppression remains the mainstay of therapy in patients with PyVAN. The combination of low dose cyclosporine plus mTOR inhibition appears to be safe and warrants further investigation.

BK virus nephropathy in a pediatric heart transplant recipient with post-transplant lymphoproliferative disorder: a case report and review of literature

BKV is known to cause allograft failure in kidney transplant recipients. It has been recently recognized to cause native kidney nephropathy in non-kidney transplant recipients. This is a case report BKVN in a 15-yr-old HTx recipient who had PTLD and a review of pediatric cases in the literature. The patient was diagnosed with BKVN +189 months after transplantation and died thirty days after diagnosis of BKVN. We identified five other cases of BKVN in pediatric non-kidney solid organ transplantation, of which all were HTx recipients. Overall, outcome was poor and BKV clearance was not achieved with reduction of immunosuppression and with current therapies. We strongly recommend that pediatric HTx recipients be tested for BKV infection if there is evidence of kidney dysfunction. We also recommend that they have an annual screening for BKV viruria and viremia with the assessment of kidney function.

Mesenchymoproliferative enteropathy associated with dual simian polyomavirus and rhesus cytomegalovirus infection in a simian immunodeficiency virus-infected rhesus macaque (Macaca mulatta)

Opportunistic viral infections are common in simian immunodeficiency virus-infected rhesus macaques and include simian polyomavirus 40 (SV40), which causes interstitial nephritis, pneumonia, meningoencephalitis, and progressive multifocal leukoencephalopathy and rhesus cytomegalovirus (Macacine herpesvirus-3), which is associated with many pathologic manifestations, including the formation of neutrophil-rich gastrointestinal masses. Herein we report the findings of a simian immunodeficiency virus-infected rhesus macaque that presented to necropsy with multiple nodular masses restricted to the proximal jejunum. Histologically, the masses within the lamina propria were composed of abundant, loosely organized, mesenchymal tissue forming broad interlacing whorls and sheets admixed with variable numbers of neutrophils. Cells within the mesenchymoproliferative nodules contained numerous basophilic, intranuclear inclusion bodies with only scattered cytomegalic cells. Immunohistochemistry for rhesus cytomegalovirus and SV40 demonstrated variable numbers of immunopositive cells within the affected nodules. This report is the first description of SV40-associated pathology in the small intestine of a rhesus macaque and highlights the role that opportunistic viral infections can have on gastrointestinal pathology in immunosuppressed rhesus macaques.

Viral infection in renal transplant recipients

Viruses are among the most common causes of opportunistic infection after transplantation. The risk for viral infection is a function of the specific virus encountered, the intensity of immune suppression used to prevent graft rejection, and other host factors governing susceptibility. Although cytomegalovirus is the most common opportunistic pathogen seen in transplant recipients, numerous other viruses have also affected outcomes. In some cases, preventive measures such as pretransplant screening, prophylactic antiviral therapy, or posttransplant viral monitoring may limit the impact of these infections. Recent advances in laboratory monitoring and antiviral therapy have improved outcomes. Studies of viral latency, reactivation, and the cellular effects of viral infection will provide clues for future strategies in prevention and treatment of viral infections. This paper will summarize the major viral infections seen following transplant and discuss strategies for prevention and management of these potential pathogens.

Opportunistic posttransplantation virus infections in renal transplant recipients

BACKGROUND

Opportunistic virus infection is one of the most common complications in renal transplant (RT) recipients. Cytomegalovirus (CMV) and BK virus (BKV) are important pathogens and each of these infections affects the other. In contrast, there is only limited information on JC virus (JCV) infection and its relation to CMV infection in RT recipients. This prospective study investigated the rates of JCV and CMV infections and their risk factors and correlations.

METHODS

We studied 52 RT recipients. JCV and CMV were detected using nested qualitative polymerase chain reaction assays of urine. The clinical characteristics of JCV and CMV infection were compared and risk factors analyzed with the use of binary logistic regression.

RESULTS

JCV and CMV were detected in 40.4% and 34.6% of the RT recipients, respectively. Cyclosporine (CsA) was a risk factor for both JCV and CMV infection (odds ratio [OR] 7.187; P=.002; OR 4.182; P=.021); CMV infection was a risk factor for JCV infection (OR 3.900; P=.039).

CONCLUSIONS

JCV and CMV infections are common in RT recipients. CsA is a risk factor for both JCV and CMV infection. JCV infection is related to CMV infection.

Dynamics of cell-mediated immune responses to cytomegalovirus in pediatric transplantation recipients

CMI responses, combined with quantification of CMV DNA (DNAemia), may identify transplantation recipients at risk for invasive disease. PBMC were collected in pediatric transplantation candidates at one, three, and six months post-transplant in 10 subjects (six renal, three cardiac, one stem cell) and at single time points in eight HC and 14 children greater than one yr post-transplant (LTTx). Cells were stimulated with anti-CD3mAb or CMV pp65 peptide pools and responses assessed by IFNG enzyme-linked immunosorbent spot assay and cytokine secretion. IFNG responses to anti-CD3mAb were significantly lower pretransplant relative to HC and were further decreased at one and three months post-transplant, but recovered to levels comparable to HC by six months. Responses to pp65 among CMV-seropositive recipients followed a similar pattern but recovered by three months. CMV-seropositive LTTx and HC showed a Th1 cytokine response to pp65 stimulation. Three LTTx subjects developed CMV DNAemia; two demonstrated decreased responses to anti-CD3mAB (and pp65 in the CMV seropositive subject) at the onset of DNAemia, which recovered as DNAemia resolved. Monitoring CMI in children is feasible and may provide an adjunct biomarker to predict CMV progression and recovery.

Use of intravenous immune globulin and rituximab for desensitization of highly HLA-sensitized patients awaiting kidney transplantation

BACKGROUND.: We have shown that high-dose intravenous immune globulin (IVIG; 2 g/kg x2 doses)+rituximab (1 g x2 doses) was effective in lowering anti-human leukocyte antigen (HLA) antibodies and improving rates of transplantation. The aim of this report was to evaluate the efficacy of IVIG+rituximab on reduction of anti-HLA antibodies to a level that was permissive for living donor (LD) or deceased donor (DD) transplantation without incurring the risk of antibody-mediated rejection and immediate graft loss. METHODS.: From July 2006 to February 2009, 76 HLA-sensitized (HS) patients who met strict sensitization criteria received kidney transplants after desensitization using IVIG 2 g/kg (days 1 and 30)+rituximab (1 g, day 15). Parameters evaluated included rates of transplantation, previous transplants, panel reactive antibodies, donor specific antibody, crossmatches (CMXs), patient and graft survival, acute rejection, serum creatinines, and infections. RESULTS.: Seventy-six HS CMX treated patients (31 LD/45 DD) were transplanted. For LD and DD recipients, significant reductions were seen in T-cell flow cytometry CMXs from pretreatment (T cell 183.5+/-98.4 mean channel shifts (MCS) for LD and 162.8+/-41 MCS for DD) to time of transplant (T cell 68.2+/-58 MCS for LD [P<0.00006] and 125+/-49 for DD [P=0.05]), respectively. Time on wait list for DD recipients was reduced from 95+/-46 months to 4.2+/-4.5 months after treatment. Twenty-eight patients (37%) experienced acute rejection (29% C4d/8% C4d). Patient and graft survival up to 24 months was 95% and 84%, respectively. The mean serum creatinines, at 12 and 24 months were 1.5+/-1.1 and 1.3+/-0.3 mg/dL, respectively. Viral infections were seen in six patients. CONCLUSIONS.: IVIG and rituximab seems to offer significant benefits in reduction of anti-HLA antibodies allowing improved rates of transplantation for HS patients, especially those awaiting DD, with acceptable antibody-mediated rejection and survival rates at 24 months.

Monitoring of BK viral load in renal allograft recipients by real-time PCR assays

BK virus (BKV) is a nonenveloped, double-stranded DNA virus of the polyomavirus family that primarily affects immunocompromised people. BKV may cause nephropathy in renal transplant recipients receiving immunosuppressive therapy, resulting in renal dysfunction and, possibly, graft loss. Monitoring of BK viral load in urine and blood has been used as a surrogate marker of BKV nephropathy (BKVN). Although real-time polymerase chain reaction (PCR) is the method of choice, currently there is no US Food and Drug Administration-approved or standardized BK viral load assay. Different PCR assays vary significantly in sample types, DNA extraction method, PCR primers and probes, and reference materials used to generate a standard curve. These differences can affect the accuracy, specificity, and dynamic ranges of various real-time PCR assays. These analytic differences cause difficulty in comparing test results, making it impossible to establish universal standardized cutoff values that correlate with clinical manifestations of BKVN. In this review, we summarize real-time PCR assays used for managing BKVN.

The safety and efficacy of a JAK inhibitor in patients with active rheumatoid arthritis: Results of a double-blind, placebo-controlled phase IIa trial of three dosage levels of CP-690,550 versus placebo

OBJECTIVE

To determine the efficacy, safety, and tolerability of 3 different dosages of CP-690,550, a potent, orally active JAK inhibitor, in patients with active rheumatoid arthritis (RA) in whom methotrexate, etanercept, infliximab, or adalimumab caused an inadequate or toxic response.

METHODS

Patients (n = 264) were randomized equally to receive placebo, 5 mg of CP-690,550, 15 mg of CP-690,550, or 30 mg of CP-690,550 twice daily for 6 weeks, and were followed up for an additional 6 weeks after treatment. The primary efficacy end point was the American College of Rheumatology 20% improvement criteria (ACR20) response rate at 6 weeks.

RESULTS

By week 6, the ACR20 response rates were 70.5%, 81.2%, and 76.8% in the 5 mg, 15 mg, and 30 mg twice daily groups, respectively, compared with 29.2% in the placebo group (P < 0.001). Improvements in disease activity in CP-690,550-treated patients compared with placebo were seen in all treatment groups as early as week 1. ACR50 and ACR70 response rates significantly improved in all treatment groups by week 4. The most common adverse events reported were headache and nausea. The infection rate in both the 15 mg twice daily group and the 30 mg twice daily group was 30.4% (versus 26.2% in the placebo group). No opportunistic infections or deaths occurred. Increases in mean low-density lipoprotein cholesterol and high-density lipoprotein cholesterol levels, and increases in mean serum creatinine level (0.04-0.06 mg/dl) were seen in all CP-690,550 treatment arms.

CONCLUSION

Our findings indicate that CP-690,550 is efficacious in the treatment of RA, resulting in rapid, statistically significant, and clinically meaningful reductions in the signs and symptoms of RA. Further studies of CP-690,550 in RA are warranted.

Treatment for BK virus: incidence, risk factors and outcomes for kidney transplant recipients in the United States

There has been a notable rise of BK virus among kidney transplant recipients. Single-center reports have identified risk factors for development of BK virus. However, there has not been an assessment of risk factors and incidence of this complication at a national level. This study utilized newly collected follow-up information from the national SRTR database to investigate incidence, risk factors and outcomes for solitary kidney transplant recipients associated with treatment for BK virus (TBKV) from 2004 to 2006. Logistic and Cox models were utilized to assess risk factors and evaluate graft survival associated with TBKV. Incidence of TBKV was 1.6% at 6 months and 2.6% at 1 year following transplantation. Patients with and without TBKV at 6 months had 79% and 90% 3-year overall graft survival respectively. Risk factors included advanced donor age, pediatric, African American and male recipients, human leukocyte antigen-mismatching and tacrolimus and thymoglobulin induction as baseline immunosuppression. Acute rejection episodes were more frequent prior to and following TBKV. TBKV is a common and rising incidence, varies based on transplant characteristics and should be included as a safety endpoint in studies investigating immunosuppressive protocols. Careful monitoring and further understanding of disease etiology and treatment strategies are needed.

Risk factors for polyoma virus nephropathy

BACKGROUND

Polyoma virus-associated nephropathy (PVN) is a common cause of renal transplant failure. The risk factors for the development of PVN have not yet been studied in large cohorts of patients for periods of 20 years.

METHODS

We collected clinical, renal biopsy and urinary cytology data from all patients with renal transplantations performed at the University Hospital of Basel from 1985 to 2005. All patients with a renal biopsy and urine cytology were included (n = 880). Renal transplants were divided into three groups, according to evidence of polyoma virus (PV) infection (decoy cells in the urine) and biopsy-proven PVN: Renal transplants without evidence of a PV infection (n = 751). Renal transplants with PV reactivation, e.g. decoy cell (DC) found by urinary cytology, but without PVN (n = 90). Renal transplants with PVN (n = 39).

RESULTS

The prevalence of biopsy-proven PVN in this cohort of patients was 3.3%. Immunosuppression with mycophenolate and/or tacrolimus, ATGAM, male gender of the recipient and a higher number of transplant rejection episodes were factors significantly associated with PVN development.

CONCLUSIONS

The most important risk factors for the development of PVN are acute rejection and ATGAM used as induction therapy as well as tacrolimus and mycophenolate as maintenance therapy. Therefore, we conclude that patients with tacrolimus and mycophenolate maintenance therapy should be carefully monitored for the development of PVN.

Clinical significance of peripheral blood Epstein-Barr viral load monitoring using polymerase chain reaction in renal transplant recipients

PTLD is a complication of EBV infection. We examined the efficacy of EBV-PCR monitoring to detect early replication in an attempt to prevent EBV-associated PTLD. Blood EBV levels in 156 renal transplant recipients (58 children) from three institutions over nine yr were retrospectively analyzed. Patients who were asymptomatic and at high risk for PTLD were monitored for EBV infection by PCR or serology followed by PCR at the time of EBV seropositivity. More children than adults had positive EBV-PCR (12/58 vs. 2/98, p < 0.001). Adults remained asymptomatic and viremia resolved post-therapy. 3/12 EBV-PCR positive children developed PTLD (3/12 children vs. 0/2 adults, p = NS). Two out of three with PTLD were initially monitored by serology, and later by PCR. PTLD resolved post-therapy in all three patients. The remaining 9/12 EBV-PCR positive children stayed asymptomatic. None of the children and adults with negative EBV-PCR developed PTLD. EBV-PCR monitoring in high-risk renal transplant recipients, especially in children, may allow early diagnosis and intervention, and therefore may help in preventing EBV-associated PTLD.

Rituximab and intravenous immune globulin for desensitization during renal transplantation

BACKGROUND

Few options for transplantation currently exist for patients highly sensitized to HLA. This exploratory, open-label, phase 1-2, single-center study examined whether intravenous immune globulin plus rituximab could reduce anti-HLA antibody levels and improve transplantation rates.

METHODS

Between September 2005 and May 2007, a total of 20 highly sensitized patients (with a mean [+/-SD] T-cell panel-reactive antibody level, determined by use of the complement-dependent cytotoxicity assay, of 77+/-19% or with donor-specific antibodies) were enrolled and received treatment with intravenous immune globulin and rituximab. We recorded rates of transplantation, panel-reactive antibody levels, cross-matching results at the time of transplantation, survival of patients and grafts, acute rejection episodes, serum creatinine values, adverse events and serious adverse events, and immunologic factors.

RESULTS

The mean panel-reactive antibody level was 44+/-30% after the second infusion of intravenous immune globulin (P<0.001 for the comparison with the pretreatment level). At study entry, the mean time on dialysis among recipients of a transplant from a deceased donor was 144+/-89 months (range, 60 to 324). However, the time to transplantation after desensitization was 5+/-6 months (range, 2 to 18). Sixteen of the 20 patients (80%) received a transplant. At 12 months, the mean serum creatinine level was 1.5+/-1.1 mg per deciliter (133+/-97 micromol per liter), and the mean survival rates of patients and grafts were 100% and 94%, respectively. There were no infusion-related adverse events or serious adverse events during the study. Long-term monitoring for infectious complications and neurologic problems revealed no unanticipated events.

CONCLUSIONS

These findings suggest that the combination of intravenous immune globulin and rituximab may prove effective as a desensitization regimen for patients awaiting a transplant from either a living donor or a deceased donor. Larger and longer trials are needed to evaluate the clinical efficacy and safety of this approach. (ClinicalTrials.gov number, NCT00642655.)