CMV infection in the donor and increased kidney graft loss: impact of full HLA-I mismatch and posttransplantation CD8(+) cell reduction

The impact of universal induction therapy on early hospital readmission of kidney transplant recipients

BACKGROUND

Early hospital readmission (EHR) is associated with worse outcomes. The use of anti-thymocyte globulin (rATG) induction therapy is associated with increased efficacy in preventing acute rejection, although safety concerns still exist.

METHODS

This retrospective single-center study compared the incidence, causes of EHR, and one-year clinical outcomes of patients receiving a kidney transplant between August 18, 2011 and December 31, 2012 (old era), in which only high-risk patients received 5 mg/kg rATG, with those transplanted between August 18, 2014 and December 31, 2015 (new era), in which all patients received a single 3 mg/kg dose of rATG.

RESULTS

There were 788 patients from the Old Era and 800 from the New Era. The EHR incidence in the old era patients was 26.4% and in the new era patients, 22.5% (p = 0.071). The main cause of EHR in both eras was infection (67% vs. 68%). The incidence of acute rejection episodes was lower (22.7% vs 3.5%, p < 0.001) and the one-year patient survival was higher (95.6% vs. 98.1%, vs. p = 0.004) in new era patients.

CONCLUSION

The universal use of 3 mg/kg rATG single-dose induction therapy in the new era was associated with a trend towards reduced EHR and a reduction in the incidence of acute rejection and mortality.

O impacto da terapia de indução universal na readmissão hospitalar precoce de receptores de transplante renal

Resumo Histórico: A Readmissão Hospitalar Precoce (RHP) está associada a piores desfechos. O uso de terapia de indução com globulina antitimócito (rATG, por sua sigla em inglês) está associado ao aumento da eficácia na prevenção de rejeição aguda, embora ainda existam preocupações quanto à segurança. Métodos: Este estudo retrospectivo de centro único comparou a incidência, as causas da RHP e os desfechos clínicos de um ano de pacientes que receberam transplante renal entre 18 de Agosto de 2011 e 31 de Dezembro de 2012 (Antiga Era), em que apenas pacientes de alto risco receberam 5 mg/kg de rATG, com aqueles transplantados entre 18 de Agosto de 2014 e 31 de Dezembro de 2015 (Nova Era), em que todos os pacientes receberam uma única dose de 3 mg/kg de rATG. Resultados: Houve 788 pacientes da Antiga Era e 800 da Nova Era. A incidência de RHP nos pacientes da antiga era foi de 26,4% e nos pacientes da nova era, 22,5% (p = 0,071). A principal causa de RHP em ambas as eras foi infecção (67% vs. 68%). A incidência de episódios de rejeição aguda foi menor (22,7% vs. 3,5%; p < 0,001) e a sobrevida do paciente em um ano foi maior (95,6% vs. 98,1%; vs. p = 0,004) em pacientes da nova era. Conclusão: O uso universal de terapia de indução de 3 mg/kg de rATG em dose única na nova era foi associado a uma tendência à redução da RHP e a uma redução na incidência de rejeição aguda e mortalidade.

Mass cytometry reveals single-cell kinetics of cytotoxic lymphocyte evolution in CMV-infected renal transplant patients

Cytomegalovirus (CMV) infection is associated with graft rejection in renal transplantation. Memory-like natural killer (NK) cells expressing NKG2C and lacking FcεRIγ are established during CMV infection. Additionally, CD8+ T cells expressing NKG2C have been observed in some CMV-seropositive patients. However, in vivo kinetics detailing the development and differentiation of these lymphocyte subsets during CMV infection remain limited. Here, we interrogated the in vivo kinetics of lymphocytes in CMV-infected renal transplant patients using longitudinal samples compared with those of nonviremic (NV) patients. Recipient CMV-seropositive (R+) patients had preexisting memory-like NK cells (NKG2C+CD57+FcεRIγ-) at baseline, which decreased in the periphery immediately after transplantation in both viremic and NV patients. We identified a subset of prememory-like NK cells (NKG2C+CD57+FcεRIγlow-dim) that increased during viremia in R+ viremic patients. These cells showed a higher cytotoxic profile than preexisting memory-like NK cells with transient up-regulation of FcεRIγ and Ki67 expression at the acute phase, with the subsequent accumulation of new memory-like NK cells at later phases of viremia. Furthermore, cytotoxic NKG2C+CD8+ T cells and γδ T cells significantly increased in viremic patients but not in NV patients. These three different cytotoxic cells combinatorially responded to viremia, showing a relatively early response in R+ viremic patients compared with recipient CMV-seronegative viremic patients. All viremic patients, except one, overcame viremia and did not experience graft rejection. These data provide insights into the in vivo dynamics and interplay of cytotoxic lymphocytes responding to CMV viremia, which are potentially linked with control of CMV viremia to prevent graft rejection.

Impact of cytomegalovirus infection on biliary disease after liver transplantation - maybe an essential factor

BACKGROUND

Cytomegalovirus (CMV) infection is common in liver transplant (LT)_ recipients, and biliary complications occur in a large number of patients. It has been reported that CMV-DNA is more detectable in bile than in blood.

AIM

To investigate the effects of CMV infection on biliary complications by comparing the levels of CMV-DNA in the bile and blood of patients after LT.

METHODS

We conducted a retrospective analysis of 57 patients who underwent LT, 10 of these patients had no biliary complications and 47 patients had biliary complications. We also compared the levels of CMV-DNA in patients’ bile and blood, which were sampled concurrently. We used RNAscope technology to identify CMV in paraffin-embedded liver sections.

RESULTS

CMV-DNA was not detected in bile samples and was detected in 2 blood samples from patients without biliary complications. In the 47 patients with biliary complications, CMV-DNA was detected in 22 bile samples and 8 blood samples, both bile and blood samples were positive for CMV-DNA in 6 patients. The identification rate of CMV-DNA in blood was 17.0%, and was 46.8% in bile. Moreover, tissue samples from 4 patients with biliary complications tested positive using RNAscope technology but were negative with hematoxylin and eosin staining. During the follow-up period, graft failure occurred in 13 patients with biliary complications, 8 of whom underwent retransplantation, and 3 died. CMV-DNA in bile was detected in 9 of 13 patients with graft failure.

CONCLUSION

In patients with biliary complications, the identification rate of CMV-DNA in bile was higher than that in blood. Blood CMV-DNA negative patients with biliary complications should still be monitored for CMV-related biliary tract diseases. Potential occult CMV infection may also be a contributing etiological factor in the development of graft failure.

Association Between Blood and Lymphocyte Levels of Cyclosporin A and Infectious Complications in Renal Transplant Patients

Objectives

This study aims to investigate a potential association between whole blood and lymphocyte Cyclosporin A (CyA) levels and the occurrence and frequency of infectious complications in kidney transplant patients.

Methods

The study involves 130 kidney transplant recipients who received CyA in addition to Mycophenolate Mofetil and steroids. CyA whole blood trough and maximum level (CyA BL₀ and CyA BLm) as well as the corresponding levels in the lymphocytes (CyA L₀ and CyA Lm) were measured for 6 months post-transplantation.

Results

Cytomegalovirus (CMV) as well as urinary tract infections (UTIs) were the most commonly diagnosed with an incidence of 24.6% and 26.2%, respectively. Only CyA L₀ showed a significant association with CMV infection occurrence (adjusted OR = 1.051, 95% CI .997–1.025, P-value 0.046). A positive linear correlation was found between CyA BL₀, CyA BLm and CyA Lm and the number of CMV episodes per patient.

Conclusion

We showed an association between the CMV infections occurrence and the trough lymphocyte level of CyA (CyA L₀). Both lymphocyte CyA levels also correlated with the frequency of CMV infections. Further studies are needed to establish the optimal range of both CyA blood and lymphocyte levels and decrease the risk of opportunistic infections in high risk patients.

Rat and human cytomegalovirus ORF116 encodes a virion envelope glycoprotein required for infectivity

Herpesviruses encode multiple glycoproteins required for different stages of viral attachment, fusion, and envelopment. The protein encoded by the human cytomegalovirus (HCMV) open reading frame UL116 forms a stable complex with glycoprotein H that is incorporated into virions. However, the function of this complex remains unknown. Herein, we characterize R116, the rat CMV (RCMV) putative homolog of UL116. Two R116 transcripts were identified in fibroblasts with three proteins expressed with molecular weights of 42, 58, and 82 kDa. R116 is N-glycosylated, expressed with late viral gene kinetics, and is incorporated into the virion envelope. RCMV lacking R116 failed to result in productive infection of fibroblasts and siRNA knockdown of R116 substantially reduced RCMV infectivity. Complementation in trans of an R116-deficient virus restored ability of the virus to infect fibroblasts. Finally, UL116 knockdown also decreased HCMV infectivity indicating that R116 and UL116 both contribute to viral infectivity.

Precision Medicine in Kidney Transplantation: Just Hype or a Realistic Hope?

Desirable outcomes including rejection- and infection-free kidney transplantation are not guaranteed despite current strategies for immunosuppression and using prophylactic antimicrobial medications. Graft survival depends on factors beyond human leukocyte antigen matching such as the level of immunosuppression, infections, and management of other comorbidities. Risk stratification of transplant patients based on predisposing genetic modifiers and applying precision pharmacotherapy may help improving the transplant outcomes. Unlike certain fields such as oncology in which consistent attempts are being carried out to move away from the "error and trial approach," transplant medicine is lagging behind in implementing personalized immunosuppressive therapy. The need for maintaining a precarious balance between underimmunosuppression and overimmunosuppression coupled with adverse effects of medications calls for a gene-based guidance for precision pharmacotherapy in transplantation. Technologic advances in molecular genetics have led to increased accessibility of genetic tests at a reduced cost and have set the stage for widespread use of gene-based therapies in clinical care. Evidence-based guidelines available for precision pharmacotherapy have been proposed, including guidelines from Clinical Pharmacogenetics Implementation Consortium, the Pharmacogenomics Knowledge Base National Institute of General Medical Sciences of the National Institutes of Health, and the US Food and Drug Administration. In this review, we discuss the implications of pharmacogenetics and potential role for genetic variants-based risk stratification in kidney transplantation. A single score that provides overall genetic risk, a polygenic risk score, can be achieved by combining of allograft rejection/loss-associated variants carried by an individual and integrated into practice after clinical validation.

Understanding human γδ T cell biology toward a better management of cytomegalovirus infection

Cytomegalovirus (CMV) infection is responsible for significant morbidity and mortality in immunocompromised patients, namely solid organ and hematopoietic cell transplant recipients, and can induce congenital infection in neonates. There is currently an unmet need for new management and treatment strategies. Establishment of an anti-CMV immune response is critical in order to control CMV infection. The two main human T cells involved in HCMV-specific response are αβ and non-Vγ9Vδ2 T cells that belong to γδ T cell compartment. CMV-induced non-Vγ9Vδ2 T cells harbor a specific clonal expansion and a phenotypic signature, and display effector functions against CMV. So far, only two main molecular mechanisms underlying CMV sensing have been identified. Non-Vγ9Vδ2 T cells can be activated either by stress-induced surface expression of the γδT cell receptor (TCR) ligand annexin A2, or by a multimolecular stress signature composed of the γδTCR ligand endothelial protein C receptor and co-stimulatory signals such as the ICAM-1-LFA-1 axis. All this basic knowledge can be harnessed to improve the clinical management of CMV infection in at-risk patients. In particular, non-Vγ9Vδ2 T cell monitoring could help better stratify the risk of infection and move forward a personalized medicine. Moreover, recent advances in cell therapy protocols open the way for a non-Vγ9Vδ2 T cell therapy in immunocompromised patients.

Early Hospital Readmission (EHR) in kidney transplantation: a review article

Early hospital readmission (EHR), defined as all readmissions within 30 days of initial hospital discharge, is a health care quality measure. It is influenced by the demographic characteristics of the population at risk, the multidisciplinary approach for hospital discharge, the access, coverage, and comprehensiveness of the health care system, and reimbursement policies. EHR is associated with higher morbidity, mortality, and increased health care costs. Monitoring EHR enables the identification of hospital and outpatient healthcare weaknesses and the implementation of corrective interventions. Among kidney transplant recipients in the USA, EHR ranges between 18 and 47%, and is associated with one-year increased mortality and graft loss. One study in Brazil showed an incidence of 19.8% of EHR. The main causes of readmission were infections and surgical and metabolic complications. Strategies to reduce early hospital readmission are therefore essential and should consider the local factors, including socio-economic conditions, epidemiology and endemic diseases, and mobility.

Low dose valganciclovir as cytomegalovirus prophylaxis in post-renal transplant recipients induced with alemtuzumab: A single-center study

OBJECTIVES

Alemtuzumab (Ale) is a recombinant monoclonal antibody which binds to CD52 causing profound lymphodepletion, thus allowing its use in renal transplantation induction therapy. However, patients may be at increased risk for opportunistic infections, such as Cytomegalovirus (CMV). We analyzed CMV infection in renal allograft recipients administered low-dose valganciclovir (VGCV) prophylaxis with alemtuzumab induction and steroid minimization.

MATERIALS AND METHODS

In this retrospective analysis, 678 kidney transplant recipients were evaluated, with 606 included for analysis. Patients were excluded for receiving induction therapy other than Ale, or for lack of follow-up within 1 year. VGCV prophylaxis was stratified by recipient CMV risk status and low-dose (450 mg) VGCV was given 3 times a week to low and moderate risk patients and daily to high risk individuals. Subject records were examined for recipient demographics, donor and recipient CMV serostatus, CMV viremia, and invasive infection.

RESULTS

Of the 606 recipients, 154 were defined as low risk for CMV infection (donor and recipient both negative, or D-/R-), 236 as moderate risk without mismatch (D+/R+), 122 as moderate risk with mismatch (D-/R+), and 94 as high risk (D+/R-). Twenty-nine (29) individuals (4.8%) tested positive by PCR for CMV viremia and 10 (1.7%) patients developed invasive CMV disease, including colitis (n = 4), esophagitis (n = 1), enteritis (n = 1), nephritis (n = 1), and pneumonia (n = 3). High risk recipients (D+/R-) accounted for the majority of invasive CMV disease (n = 5), followed by moderate risk (n = 4). CMV viremia was also more common in high risk and moderate risk (D+/R+) individuals. Overall rejection rate for our study population was 27%.

CONCLUSION

In this institution's experience, CMV incidence was reduced compared to historically reported data by using low-dose (450 mg) VGCV prophylaxis in combination with Ale induction and steroid minimization. However, overall rejection rate was significantly higher in our population, possibly influenced by the degree of steroid minimization.

New therapies for human cytomegalovirus infections

The recent approval of letermovir marks a new era of therapy for human cytomegalovirus (HCMV) infections, particularly for the prevention of HCMV disease in hematopoietic stem cell transplant recipients. For almost 30 years ganciclovir has been the therapy of choice for these infections and by today's standards this drug exhibits only modest antiviral activity that is often insufficient to completely suppress viral replication, and drives the selection of drug-resistant variants that continue to replicate and contribute to disease. While ganciclovir remains the therapy of choice, additional drugs that inhibit novel molecular targets, such as letermovir, will be required as highly effective combination therapies are developed not only for the treatment of immunocompromised hosts, but also for congenitally infected infants. Sustained efforts, largely in the biotech industry and academia, have identified additional highly active lead compounds that have progressed into clinical studies with varying levels of success and at least two have the potential to be approved in the near future. Some of the new drugs in the pipeline inhibit new molecular targets, remain effective against isolates that have developed resistance to existing therapies, and promise to augment existing therapeutic regimens. Here, we will describe some of the unique features of HCMV biology and discuss their effect on therapeutic needs. Existing drugs will also be discussed and some of the more promising candidates will be reviewed with an emphasis on those progressing through clinical studies. The in vitro and in vivo antiviral activity, spectrum of antiviral activity, and mechanism of action of new compounds will be reviewed to provide an update on potential new therapies for HCMV infections that have progressed significantly in recent years.

CMV-infected kidney grafts drive the expansion of blood-borne CMV-specific T cells restricted by shared class I HLA molecules via presentation on donor cells

We aimed to determine the role of cytomegalovirus (CMV)-infected donor cells in the development of a CMV-specific immune response in kidney transplant recipients. We assessed the CMV pp65-specific immune response by using interferon-ɣ ELISPOT and dextramers in peripheral blood mononuclear cells from 115 recipients (D+R- 31, D+R + 44, D-R + 40) late after transplantation (mean 59 ± 42 months). Receiving a kidney from a D+ donor resulted in a higher number of IFN-ɣ-producing anti-CMV T cells (P = .004). This effect disappeared with the absence of shared HLA class I specificities between donors and recipients (P = .430). To confirm the role of donor cells in stimulating the expansion of newly developed CMV-specific CD8⁺ T cells after transplantation, we compared the number of HLA-A2-restricted CMV-specific CD8⁺ T cells in primo-infected recipients who received an HLA-A2 or non-HLA-A2 graft. The median of anti-CMV pp65 T cells restricted by HLA-A2 was very low for patients who received a non-HLA-A2 graft vs an HLA-A2 graft (300 [0-14638] vs. 17972 [222-85594] anti-CMV pp65 CD8⁺ T cells/million CD8⁺ T cells, P = .001). This adds new evidence that CMV-infected kidney donor cells present CMV peptides and drive an inflation of memory CMV-specific CD8⁺ T cells, likely because of frequent CMV replications within the graft.

Maternal and child human leukocyte antigens in congenital cytomegalovirus infection

Congenital Cytomegalovirus infection (cCMV) is the most common cause of congenital infections worldwide causing permanent long-term impairment (LTI). cCMV immunopathogenesis remains largely unknown due to the complex interplay between viral, maternal, placental and child factors. The aim of this study was to determine the possible role of particular HLA antigens, of the number of HLA mismatches (mm) and non-inherited maternal antigens (NIMAs) in a large retrospective nation-wide cohort of children with cCMV and their mothers. HLA Class I (HLA-A, HLA-B and HLA-C) and HLA Class II (HLA-DR and HLA-DQ) were assessed in 96 mother-child pairs in relation to a control group of 5604 Dutch blood donors, but no significant differences were observed. Next, although these HLA antigens could not be assessed in relation to symptoms at birth, nor to LTI, due to the low number of cases, they could be evaluated in relation to CMV viral load. HLA-DRB1*04, and potentially HLA-B*51, was shown to have a protective role in the children as its frequency was increased in the low viral load group compared to the high viral load group, and this remained significant after correction. The number of HLA mm and of NIMAs were not associated to symptoms at birth nor to LTI or viral load. In conclusion, although none of the HLA alleles could be put forward as prognostic marker for long-term outcome, our findings give useful insights into cCMV pathogenesis, and identify potential HLAs that correlate with a better viral control.

Cox Regression Model Analysis of Infection in Renal Transplants After Operation

BACKGROUND

The objective of this study was to explore the factors that affect infections after renal transplant, establishing the Cox model to forecast infection for patients of renal transplant.

METHODS

Data were collected from patients who had renal transplantation in Nanking Jinlin Hospital from January 2011 to April 2015 (n = 305 transplants). There were 296 individual data that could be used after deleting the people who were lacking some data, changing the main immunosuppressants during the first year, losing follow-up, and data writing that was not fully 1 year after the operation; 296 individuals were divided by 3:7. The 206 data of patients (7/10 of the total individuals) were used to analyze and build a model, and the rest of the data were used to verify the model, analyzing the 206 data with Cox regression, discovering the factors that affect the infection after renal transplant independently, building the model, and verification.

RESULTS

Cox regression showed that there are three independent factors that affect infections after renal transplant: X3, the donor type (relative risk [RR] = 1.929, P = .037); X9, dialysis time (RR = 1.017, P = .032); and X13, human leukocyte antigen (HLA) match (RR = 0.257, P = .013). The model is: PI = 0.657X3 + 0.017X9 - 1.359X13. All PI for the 206 individuals were calculated and then divided into three groups: the low-risk group, the median-risk group, and the high-risk group. The model was verified by calculating the PI for all 90 people. The log-rank test showed that the survival rates among these groups were significantly different (P < .001).

CONCLUSIONS

Donor type, dialysis time, and HLA match are all factors that affect infection after renal transplant. Donor type and dialysis time were the dangerous factors for infection, but HLA match was the protecting factor. The model depends on these three factors and could forecast infection after renal transplant.

Hypogammaglobulinemia and risk of severe infection in kidney transplant recipients

BACKGROUND

Recent data have outlined a link between hypogammaglobulinemia (HGG) and infection risk and suggested that HGG correction may decrease post-transplant infections.

METHODS

We analyzed the risk factors of HGG and the relationship between HGG and the risk of severe infection in a cohort of 318 kidney transplant recipients (KTR) who were transplanted between 2003 and 2013. Immunoglobulin (Ig) concentration was measured prospectively at day 15 (D15), month 6 (M6), month 12 (M12), and month 24 (M24) post transplant.

RESULTS

The prevalence of IgG HGG was 56% and 36.8% at D15 and M6, respectively. Age was the sole identified risk factors for D15 IgG HGG (odds ratio [OR] 1.02, P = 0.019). Risk factors for M6 IgG HGG were the presence of D15 IgG HGG (OR 6.41, P < 0.001) and treatment of acute rejection (OR 2.63, P = 0.014). Most infections occurred between D15 and M6 post transplant. Only age (hazard ratio 1.03, P < 0.001) was identified as a risk factor of infection between D15 and M6 post transplant. Survival free of infection (overall infections and bacterial or viral infections) did not differ significantly between patients with or without D15 IgG HGG. Only septicemia occurring between M6 and M12 post transplant was more frequently observed in patients with HGG. The low prevalence of severe HGG (<400 mg/dL) did not allow conclusions on the infectious risk associated with this patient subgroup.

CONCLUSIONS

This study does not support the existence of a strong link between post-transplant HGG and the risk of severe infections in KTR. Correction of HGG to minimize the risk of severe infections in KTR is thus questionable and needs to be reevaluated in prospective studies.

Polymorphism in programmed cell death 1 gene is strongly associated with lung and kidney allograft survival in recipients from CMV-positive donors

BACKGROUND

Cytomegalovirus (CMV) has a role in chronic rejection and graft loss in kidney transplant (KTx) and lung transplant (LTx) recipients. In addition, donor CMV seropositivity is an independent risk factor for renal graft loss. The anti-CMV response might modulate this risk. Expression of programmed cell death 1 (PD-1), a receptor involved in viral-specific T-cell exhaustion, is influenced by a single nucleotide polymorphism called PD-1.3 (wild-type allele G, variant allele A).

METHODS

We performed a retrospective study to assess the impact of PD-1.3 on graft outcome in donor CMV seropositive (D+) and donor CMV seronegative (D-) KTx and LTx. We also performed a case-control study to evaluate the anti-CMVpp65 response according to genotype.

RESULTS

PD-1.3 was determined in 1,119 KTx and 181 LTx. In 481 D+ KTx, A allele carriers (24%) experienced significantly less graft failure compared with GG carriers (p = 0.001). Multivariate analysis showed that this association was independent of donor and recipient age, acute rejection episodes, and number of human leukocyte antigen mismatches (hazard ratio, 0.381; 95% confidence interval, 0.209-0.696; p = 0.002). Analysis in 85 D+ LTx showed similar results: A allele carriers had better survival (hazard ratio, 0.302; 95% confidence interval, 0.128-0.716; p = 0.006) and greater 6-month forced expiratory volume (71% ± 17% vs 54% ± 16%, p = 0.001). In D- recipients, PD-1.3 did not affect KTx or LTx outcome. Finally, AA recipients had a stronger anti-CMVpp65 T-cell response than matched GG recipients (p = 0.003).

CONCLUSIONS

The A variant allele in PD-1.3 single nucleotide polymorphism improved graft survival in kidney and lung transplant recipients receiving grafts from CMV-positive donors.

Long-term impact of CMV infection on allografts and on patient survival in renal transplant patients with protocol biopsies

Cytomegalovirus (CMV) infection is a frequent complication of early posttransplantation. This study examines its impact on chronic allograft changes, long-term graft loss, and patient survival. We studied 594 patients who had protocol biopsies at 6 wk, and 3 and 6 mo posttransplantation. Chronic allograft changes were evaluated according to the updated Banff classification [interstitial fibrosis/tubular atrophy (IF/TA), vascular and glomerular lesions]. Follow-up data were available for up to 10 yr. CMV infection was diagnosed in 153 of 594 patients (26%) in the first year after transplantation, mostly within the first 3 mo. Graft survival was reduced in patients with CMV ( P = 0.03) as well as the combined allograft/patient survival ( P = 0.008). Prevalence of IF/TA at 6 wk after transplantation was already threefold higher in patients who experienced CMV infection later on compared with patients without CMV ( P = 0.005). In multivariate analyses, CMV viremia or disease was not a significant factor for graft loss or death. In conclusion, patients with CMV infection posttransplantation show more chronic allograft changes early on, even before CMV infection, and development of IF/TA is not more prevalent in patients with CMV. Our data do not support a significant role of CMV in patient and graft outcomes.

The polyomavirus puzzle: is host immune response beneficial in controlling BK virus after adult hematopoietic cell transplantion?

BK virus (BKV), a ubiquitous human polyomavirus, usually does not cause disease in healthy individuals. BKV reactivation and disease can occur in immunosuppressed individuals, such as those who have undergone renal transplantation or hematopoietic cell transplantation (HCT). Clinical manifestations of BKV disease include graft dysfunction and failure in renal transplant recipients; HCT recipients frequently experience hematuria, cystitis, hemorrhagic cystitis (HC), and renal dysfunction. Studies of HCT patients have identified several risk factors for the development of BKV disease including myeloablative conditioning, acute graft-versus-host disease, and undergoing an umbilical cord blood (uCB) HCT. Although these risk factors indicate that alterations in the immune system are necessary for BKV pathogenesis in HCT patients, few studies have examined the interactions between host immune responses and viral reactivation in BKV disease. Specifically, having BKV immunoglobulin-G before HCT does not protect against BKV infection and disease after HCT. A limited number of studies have demonstrated BKV-specific cytotoxic T cells in healthy adults as well as in post-HCT patients who had experienced HC. New areas of research are required for a better understanding of this emerging infectious disease post HCT, including prospective studies examining BK viruria, viremia, and their relationship with clinical disease, a detailed analysis of urothelial histopathology, and laboratory evaluation of systemic and local cellular and humoral immune responses to BKV in patients receiving HCT from different sources, including uCB and haploidentical donors.

Successful three-way kidney paired donation with compatible pairs to increase donor pool

Despite heightened international interest in performing living donor kidney paired donation (KPD) transplantation after the publication of a research protocol by Ross and colleagues in 1997, only a few hundred have been performed worldwide. The major obstacle is that many individuals in end-stage renal disease are of blood type O and can only receive an organ from a donor of blood type O, whereas blood type O donors are "universal donors" and will be able to donate directly with an intended recipient of any blood type unless there is a positive crossmatch. To overcome this, patients with compatible but non-HLA identical donors over 45 years of age should be approached for inclusion in KPD program especially O blood group donors. Inclusion of all these additional pairs into the algorithm greatly increases chances of possible matches for O blood group recipients. We report successful three-way KPD transplantation resulting in transplantation of O blood group patient using compatible O blood group donor from India. None of the patients had delayed graft function or rejection and all had stable graft function on discharge without any medical and surgical complications. We need to allocate O blood group kidneys from compatible donors to overcome the barrier of HLA, non-HLA antibodies and other donor related factors to improve transplant quality and long term outcomes. This will increase transplantation of O blood group patients.