Comparative analysis of post‐transplant lymphoproliferative disorder after kidney transplantation versus hematopoietic stem cell transplantation

Post‐transplant lymphoproliferative disorder (PTLD) is a major complication caused by immune‐suppression after transplantation. Survival outcome is known to be poor and the characteristics are not fully understood because of its rare incidence. This single center retrospective study enrolled 41 adult PTLD patients after kidney‐transplantation (KT, n = 28) and hematopoietic stem cell transplantation (HSCT, n = 13) from 1992 to 2012. We compared the characteristics and estimated the survival outcomes according to several factors [age‐adjusted‐IPI (aaIPI), pathologic subtype, viral status, extranodal manifestation] and added some significant parameters to aaIPI scoring system. Post‐HSCT‐PTLD patients were younger and showed earlier onset, and viral status was more frequently identified. Ten‐year OS of the entire group was 44% but the 10‐year OS was not significantly different between post‐KT‐PTLD and post‐HSCT‐PTLD (39% vs. 56%, P = 0.860). The time onset of PTLD and viral statuses were not meaningful, however, aaIPI, age > 50, extranodal manifestation and monomorphic subtype were predictive for OS. We used those factors for PTLD‐specific scoring which showed intermediate‐risk (HR = 7.1, P = 0.019) and high‐risk (HR = 16.5, P = 0.001) presented worse OS compared to low‐risk subgroup. Although the treatment strategies were heterogenous, this study showed comprehensive PTLD data between KT versus HSCT, and our PTLD‐specific scoring might be validated by another larger studies.     

Systematic review and meta‐analysis of post‐transplant lymphoproliferative disorder in lung transplant recipients

A systematic review of papers in English on post‐transplant lymphoproliferative disorder (PTLD) in lung transplant recipients (LTR) using MEDLINE, EMBASE, SCOPUS, and Cochrane databases was performed. The Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) recommendations were strictly adhered to. Pooled odds ratios (pOR) were calculated from a random‐effects model, and heterogeneity among studies was quantitated using I² values. Fourteen studies published from 2005 to 2015 were included in the meta‐analysis. One hundred and sixty‐four lung transplant recipients were included. LTRs who received single vs bilateral were associated with a 7.67‐fold risk of death after PTLD (6 studies with 64 LTRs; pOR 7.67 95% CI 1.98‐29.70; P = .003). pOR of death for early onset PTLD (<1 year post‐LT) vs late onset (> 1 year post‐LT) was not different (3 studies with 72 LTRS; pOR 0.62, 95% CI 0.20‐1.86, P = .39). Standardized mean difference (SMD) in time from transplant to PTLD onset between LTRs who died vs alive was not different (9 studies with 109 LTRs; SMD 0.03, 95% CI ?0.48‐0.53, P = .92). Survival in polymorphic vs monomorphic PTLD and extranodal vs nodal disease was similar (4 studies with 31 LTRs; pOR 0.44, 95% CI 0.08‐2.51; P = .36. 6 studies with 81 LTRs; pOR 1.05 95% CI 0.31‐3.52, P = .94). This meta‐analysis demonstrates that single LTRs are at a higher risk of death vs bilateral LTRs after the development of PTLD.     

Idiopathic pulmonary fibrosis lung transplant recipients are at increased risk for EBV‐associated posttransplant lymphoproliferative disorder and worse survival

Epstein‐Barr virus (EBV)–associated posttransplant lymphoproliferative disorder (EBV‐PTLD) is a serious complication in lung transplant recipients (LTRs) associated with significant mortality. We performed a single‐center retrospective study to evaluate the risks for PTLD in LTRs over a 7‐year period. Of 611 evaluable LTRs, we identified 28 cases of PTLD, with an incidence of 4.6%. Kaplan‐Meier analysis showed a decreased freedom from PTLD in idiopathic pulmonary fibrosis (IPF)‐LTRs (P < .02). Using a multivariable Cox proportional hazards model, we found IPF (hazard ratio [HR] 3.51, 95% confidence interval [CI] 1.33‐8.21, P = .01) and alemtuzumab induction therapy (HR 2.73, 95% CI 1.10‐6.74, P = .03) as risk factors for PTLD, compared to EBV mismatch (HR: 34.43, 95% CI 15.57‐76.09, P < .0001). Early PTLD (first year) was associated with alemtuzumab use (P = .04), whereas IPF was a predictor for late PTLD (after first year) (P = .002), after controlling for age and sex. Kaplan‐Meier analysis revealed a shorter time to death from PTLD in IPF LTRs compared to other patients (P = .04). The use of alemtuzumab in EBV mismatch was found to particularly increase PTLD risk. Together, our findings identify IPF LTRs as a susceptible population for PTLD. Further studies are required to understand the mechanisms driving PTLD in IPF LTRs and develop strategies to mitigate risk.     

Posttransplant lymphoproliferative disorder in pediatric patients: Survival rates according to primary sites of occurrence and a proposed clinical categorization

Posttransplant lymphoproliferative disorder (PTLD) is a devastating complication of organ transplant. In a hospital‐based registry, we identified biopsy‐proven cases of PTLD among children during a 15‐year period and reviewed trends in PTLD rates, the sites of involvement, and the associated survival rates. Cases that were included had at least 1 year of follow‐up after the diagnosis of PTLD. We studied 82 patients with first‐episode PTLD. Median age at diagnosis was 6.4 years (IQR 3.2‐12.3 years). The most frequent PTLD sites were tonsillar/adenoidal (T/A [34%]) and gastrointestinal (32%), followed by miscellaneous (defined as less common sites including central nervous system, kidney, lung, and soft tissue [12%]), lymph node (11%), and multisite (11%). Kaplan‐Meier survival curves showed that T/A PTLD was associated with decreased all‐cause mortality compared with PTLD at other sites (log‐rank 0.004), even after adjustment for histological subtype (P = .047). PTLD‐related mortality was also decreased among T/A PTLD (log‐rank 0.012) but showed a trend toward significance only after adjustment for histological subtype (P = .09). Among first episodes of PTLD, T/A PTLD was associated with a survival advantage compared with PTLD at other sites, even after adjustment for potential confounders. Based on our observations, we propose a clinical categorization of PTLD according to anatomical site of occurrence.     

Characteristics,risks, and outcomes of post‐transplant lymphoproliferative disease >3 years after pediatric heart transplant: A multicenter analysis

Post‐transplant lymphoproliferative disorder (PTLD) is a significant complication after pediatric heart transplantation (HT), occurring in 5%‐15% of patients within 3 years. Data >3 years from HT are limited. We sought to describe the prevalence, risk factors, and outcomes of PTLD occurring late (>3 years) after pediatric HT in the Pediatric Heart Transplant Study from 1993 to 2010. Among 3844 primary HT patients, 110 (3%) developed late, nonrecurrent PTLD. The hazard rate for late PTLD was constant at 0.01 events/year out to 20 years after HT. Risk factors for late PTLD were younger age at HT (HR 1.06, P = 0.003) and Epstein‐Barr virus (EBV) naivety (HR 1.65, P = 0.02). Survival after late PTLD was 86% and 68% at 1 and 5 years, with nonwhite race (HR 2.27, P = 0.03) and earlier year of HT (HR 1.03, P = 0.04) independently associated with mortality. Acute rejection and infection were both common after late PTLD, occurring in 26% and 34% of patients. The constant late hazard and contribution of EBV to late PTLD suggest that vigilance for development of PTLD, including for EBV conversion, should persist indefinitely after pediatric HT. The reasons for elevated risk of death for nonwhites after late PTLD are unclear and warrant further investigation.     

Outcomes and survival analysis of old‐to‐old simultaneous pancreas and kidney transplantation

Outcomes of old‐donor simultaneous pancreas–kidney transplantation (SPKT) have not been thoroughly studied. Scientific Registry of Transplant Recipients data reported for SPKT candidates receiving dialysis wait‐listed between 1993 and 2008 (n = 7937) were analyzed for outcomes among those who remained listed (n = 3301) and of SPKT recipients (n = 4636) using multivariable time‐dependent regression models. Recipients were stratified by donor/recipient age (cutoff 40 years) into: young‐to‐young (n = 2099), young‐to‐old (n = 1873), old‐to‐young (n = 293), and old‐to‐old (n = 371). The overall mortality was 12%, 14%, 20%, and 24%, respectively, for those transplanted, and 50% for those remaining on the waiting list. On multivariable analysis, old‐donor SPKT was associated with significantly higher overall risks of patient death, death‐censored pancreas, and kidney graft failure in both young (73%, 53%, and 63% increased risk, respectively) and old (91%, 124%, and 85% increased risk, respectively) recipients. The adjusted relative mortality risk was similar for recipients of old‐donor SPKT compared with wait‐listed patients including those who subsequently received young‐donor transplants (aHR 0.95; 95% CI 0.78, 1.12) except for candidates in OPOs with waiting times ≥604 days (aHR 0.65, 95% CI 0.45–0.94). Old‐donor SPKT results in significantly worse graft survival and patient mortality without any waiting‐time benefit as compared to young‐donor SPKT, except for candidates with expected long waiting times.     

CNI withdrawal for post‐transplant lymphoproliferative disorders in kidney transplant is an independent risk factor for graft failure and mortality

Post‐transplantation lymphoproliferative disorders (PTLD) are associated with poor patient and graft survival. The risk of rejection and subsequent graft loss are increased by the reduction of immunosuppression therapy, the cornerstone of PTLD treatment. This multicentre, retrospective, nonrandomized cohort study includes 104 adults who developed PTLD after renal or simultaneous renal/pancreatic transplantation between 1990 and 2007. It examines the effect of calcineurin inhibitor (CNI) withdrawal on long‐term graft and patient survival. At 10 years postonset of PTLD, the Kaplan–Meier graft loss rate was 43.9% and graft loss or death with functioning graft was 64.4%. Cox multivariate analysis determined risk factors of graft loss as PTLD stage greater than I‐II and CNI withdrawal, and for graft loss and mortality, these remained risk factors along with age over 60 years. Type and location of PTLD, year of diagnosis, and chemotherapy regime were not independent risk factors. Multivariate analysis determined CNI withdrawal as the most important risk factor for graft loss (HR = 3.07, CI 95%: 1.04–9.09; P = 0.04) and death (HR: 4.00, CI 95%: 1.77–9.04; P < 0.001). While long‐term stable renal function after definitive CNI withdrawal for PTLD has been reported, this review determined that withdrawal is associated with reduced graft and patient survival.     

Transplantation of solid organ recipients shedding Epstein‐Barr virus DNA pre‐transplant: A prospective study

Epstein‐Barr virus (EBV) poses a significant threat to patient and graft survival post‐transplant. We hypothesized that recipients who shed EBV at transplant had less immunologic control of the virus and hence were more likely to have active EBV infection and disease post‐transplant. To test this hypothesis, we conducted a 5‐year prospective study in primary solid organ transplant recipients. We measured EBV DNA in oral washes and blood samples by quantitative PCR before transplant and periodically thereafter for up to 4 years. Pre‐transplant samples were available from 98 subjects. EBV DNA was detected pre‐transplant in 32 of 95 (34%) and 5 of 93 subjects (5%) in oral wash and blood, respectively. Recipients with and without detectable pre‐transplant EBV DNA were not significantly different demographically and had no significant difference in patient and graft survival (P = .6 for both comparisons) or post‐transplant EBV viremia‐free survival (P = .8). There were no cases of EBV‐related disease or post‐transplant lymphoproliferative disorder (PTLD) in any of the patients with detectable EBV DNA pre‐transplant. In conclusion, detectable EBV DNA pre‐transplant was not associated with differences in patient/graft survival, post‐transplant EBV viremia, or EBV‐related diseases including PTLD.     

Minimization of maintenance immunosuppressive therapy after renal transplantation comparing cyclosporine A/azathioprine or cyclosporine A/mycophenolate mofetil bitherapy to cyclosporine A monotherapy: a 10‐year postrandomization follow‐up study

Long‐term outcomes in renal transplant recipients withdrawn from steroid and submitted to further minimization of immunosuppressive regimen after 1 year are lacking. In this multicenter study, 204 low immunological risk kidney transplant recipients were randomized 14.2 ± 3.7 months post‐transplantation to receive either cyclosporine A (CsA) + azathioprine (AZA; n = 53), CsA + mycophenolate mofetil (MMF; n = 53), or CsA monotherapy (n = 98). At 3 years postrandomization, the occurrence of biopsy for graft dysfunction was similar in bitherapy and monotherapy groups (21/106 vs. 26/98; P = 0.25). At 10 years postrandomization, patients’ survival was 100%, 94.2%, and 95.8% (P = 0.25), and death‐censored graft survival was 94.9%, 94.7%, and 95.2% (P = 0.34) in AZA, MMF, and CsA groups, respectively. Mean estimated glomerular filtration rate was 70.4 ± 31.1, 60.1 ± 22.2, and 60.1 ± 19.0 ml/min/1.73 m², respectively (P = 0.16). The incidence of biopsy‐proven acute rejection was 1.4%/year in the whole cohort. None of the patients developed polyomavirus‐associated nephropathy. The main cause of graft loss (n = 12) was chronic antibody‐mediated rejection (n = 6). De novo donor‐specific antibodies were detected in 13% of AZA‐, 21% of MMF‐, and 14% of CsA‐treated patients (P = 0.29). CsA monotherapy after 1 year is safe and associated with prolonged graft survival in well‐selected renal transplant recipient ( ClinicalTrials.gov number: 980654).     

Distinct immunopathological mechanisms of EBV-positive and EBV-negative posttransplant lymphoproliferative disorders

EBV-positive and EBV-negative posttransplant lymphoproliferative disorders (PTLDs) arise in different immunovirological contexts and might have distinct pathophysiologies. To examine this hypothesis, we conducted a multicentric prospective study with 56 EBV-positive and 39 EBV-negative PTLD patients of the K-VIROGREF cohort, recruited at PTLD diagnosis and before treatment (2013–2019), and compared them to PTLD-free Transplant Controls (TC, n = 21). We measured absolute lymphocyte counts (n = 108), analyzed NK- and T cell phenotypes (n = 49 and 94), and performed EBV-specific functional assays (n = 16 and 42) by multiparameter flow cytometry and ELISpot-IFNγ assays (n = 50). EBV-negative PTLD patients, NK cells overexpressed Tim-3; the 2-year progression-free survival (PFS) was poorer in patients with a CD4 lymphopenia (CD4⁺<300 cells/mm³, p <  .001). EBV-positive PTLD patients presented a profound NK-cell lymphopenia (median = 60 cells/mm³) and a high proportion of NK cells expressing PD-1 (vs. TC, p = .029) and apoptosis markers (vs. TC, p < .001). EBV-specific T cells of EBV-positive PTLD patients circulated in low proportions, showed immune exhaustion (p = .013 vs. TC) and poorly recognized the N-terminal portion of EBNA-3A viral protein. Altogether, this broad comparison of EBV-positive and EBV-negative PTLDs highlight distinct patterns of immunopathological mechanisms between these two diseases and provide new clues for immunotherapeutic strategies and PTLD prognosis.     

Intraoperative Radiotherapy of Early Breast Cancer Using Low‐Kilovoltage X‐Rays‐Reasons for Omission of Planned Intraoperative Irradiation

The purpose of this study is to investigate reasons for omission of a planned intraoperative radiotherapy (IORT) during breast‐conserving surgery (BCS). Between 2002 and 2009, in 297 women an IORT during BCS was planned. In 55 women this irradiation was finally not performed. We retrospectively analyzed pre‐, peri‐, and postoperative data of these 55 women. Main reasons for omission of an IORT were insufficient tumor–skin distance (n = 20, 35.1%), an oversized wound cavity (n = 14, 24.6%), and a combination of both (n = 8, 14%). Further reasons (n = 12, 21.1%) were temporal shortage, unplanned maintenance work of the Intrabeam^® device, unsuitable anatomicosurgical conditions, and ineligible histologic findings. Apart from suitable anatomic conditions, a precise preoperative ultrasonography as well as a strict interdisciplinary preoperative management is important for successful application of IORT.     

Clinical characteristics and outcomes of PTLD following intestinal transplantation

Post‐transplant lymphoproliferative disease (PTLD) has the highest incidence following intestinal transplantation (ITx). Our center has seen a recent increase in PTLD. Our aim was to review a single‐center PTLD experience with a focus on clinical characteristics and outcomes. We completed a retrospective review of biopsy‐proven PTLD cases using a prospectively maintained database of 115 ITx recipients transplanted between 1991 and 2014. Nineteen (17%) ITx recipients developed 25 PTLD cases during a median follow‐up time of 6.4 (1.6‐14.6) years. The incidence of early PTLD was 6% (n = 7). There was a trend toward increased risk of PTLD in children compared with adults (P = .11) and a significantly increased risk of PTLD in re‐ITx compared with primary ITx recipients (P = .03). Most PTLD cases were diagnosed between 2010 and 2014 (n = 14). All early PTLD cases were EBV+ on in situ hybridization. Overall graft and patient survival are 68% and 74%, respectively. Second episodes of PTLD were diagnosed in 43% of surviving pediatric patients. Our program has a low incidence of early PTLD with overall excellent graft and patient survival following diagnosis. However, we have also seen a rising incidence of late PTLD. The cause of the increase is unknown as no major changes in immunosuppression protocols have occurred since 1999.     

Risk factors for post‐transplant lymphoproliferative disorder after Thymoglobulin‐conditioned hematopoietic cell transplantation

Epstein‐Barr virus (EBV)‐induced post‐transplant lymphoproliferative disorder (PTLD) occurs frequently when rabbit antithymocyte globulin (ATG) is used in hematopoietic cell transplant (HCT) conditioning. We retrospectively studied 554 patients undergoing ATG‐conditioned myeloablative HCT. Strategies used to minimize mortality due to PTLD were either therapy of biopsy‐diagnosed PTLD in the absence of EBV DNAemia monitoring (n = 266) or prompt therapy of presumed PTLD (based on clinical/radiologic signs and high EBV DNAemia, in the setting of weekly EBV DNAemia monitoring) (n = 199). Both strategies resulted in similar mortality due to PTLD (0.7% vs 1% at 2 years, P = .43) and similar overall survival (63% vs 67% at 2 years, P = .23) even though there was a trend toward higher PTLD incidence with the prompt therapy. Donor positive with recipient negative EBV (D+R?) serostatus was a risk factor for developing PTLD. Older patient age, HLA‐mismatched donor, and graft‐versus‐host disease were not associated with increased risk of PTLD. In summary, in ATG‐conditioned HCT, D+R? serostatus, but not older age, mismatched donor or GVHD is a risk factor for developing PTLD. EBV DNAemia monitoring may be a weak risk factor for developing/diagnosing PTLD; the monitoring coupled with prompt therapy does not improve survival.     

Mesangial expansion at 5 years predicts death and death‐censored graft loss after renal transplantation

Death with a functioning graft and death‐censored renal allograft failure remain major problems for which effective preventative protocols are lacking. The retrospective cohort study aimed to determine whether histologic changes on a 5‐year surveillance kidney biopsy predict adverse outcomes after transplantation in recipients who had: both Type 2 diabetes (T2DM) and obesity (BMI ≥ 30 kg/m²) at the time of transplantation (T2DM/Obesity, n = 75); neither (No T2DM/No obesity, n = 78); No T2DM/Obesity (n = 41), and T2DM/No obesity (n = 47). On 5‐year biopsies, moderate‐to‐severe mesangial expansion was more common in the T2DM/Obesity group (Banff mm score ≥2 = 49.3%; Tervaert classification MS ≥ 2b = 26.7%) compared to the other groups (p < .001 for both scores). Risk factors included older age, higher BMI, HbA1C, and triglycerides at 1‐year post‐transplant. Moderate‐to‐severe mesangial expansion correlated with death with function (HR 1.74 (1.01, 2.98), p = .045 Banff and 1.89 (1.01, 3.51) p = .045 Tervaert) and with death‐censored graft loss (HR 3.2 (1.2, 8.8), p = .02 Banff and HR 3.8 (1.3, 11.5), p = .01 Tervaert) over a mean of 11.6 years of recipient follow‐up post‐transplant. These data suggest that mesangial expansion in recipients with T2DM and obesity may reflect systemic vascular injury and might be a novel biomarker to predict adverse outcomes post renal transplant.     

Post‐transplant lymphoproliferative disease in lung transplantation: A nested case‐control study

Post‐transplant lymphoproliferative disorder (PTLD) may compromise long‐term outcome of lung transplant (LTx) recipients. A case‐control study was performed, comparing LTx recipients with PTLD (n=31) to matched recipients without PTLD (Controls, n=62). Risk factors for PTLD and post‐transplant outcomes were assessed. PTLD prevalence was 3.9%, time to PTLD 323 (166‐1132) days; and 54.8% had early‐onset PTLD versus 45.2% late‐onset PTLD. At LTx, more Epstein‐Barr virus (EBV)‐seronegative patients were present in PTLD (42%) compared to Controls (5%) (P<.0001); most of whom had undergone EBV seroconversion upon PTLD diagnosis. EBV viral load was higher in PTLD versus Controls (P<.0001). Overall, lower hemoglobin and higher C‐reactive protein levels were present in PTLD versus Controls (P<.0001). EBV status at LTx (P=.0073) and EBV viral load at PTLD (P=.0002) were the most important risk determinates for later PTLD. Patients with PTLD demonstrated shorter time to onset of chronic lung allograft dysfunction (CLAD) (P=.0006) and poorer 5‐year survival post‐LTx (66.6% versus 91.5%), resulting in worse CLAD‐free survival (HR 2.127, 95%CI 1.006‐4.500; P=.0483) and overall survival (HR 3.297 95%CI 1.473‐7.382; P=.0037) compared to Controls. Late‐onset PTLD had worse survival compared to early‐onset PTLD (P=.021). Primary EBV infection is a risk for PTLD; which is associated with worse long‐term outcome post‐LTx.     

Post‐transplant lymphoproliferative disorder following kidney transplantation: a population‐based cohort study

Post‐transplant lymphoproliferative disorder (PTLD) incidence is difficult to determine, mainly because both early and other lesions may go unrecognized and unregistered. Few studies have included systematic pathology review to maximize case identification and decide more accurately PTLD frequency after long‐term post‐transplantation follow‐up. A retrospective population‐based cohort study including all kidney transplant recipients at two Danish centres (1990–2011; population covered 3.1 million; 2175 transplantations in 1906 patients). Pathology reports were reviewed for all patient biopsies to identify possible PTLDs. Candidate PTLDs underwent histopathological review and classification. Seventy PTLD cases were identified in 2175 transplantations (3.2%). The incidence rate (IR) after first transplantation was 5.4 cases per 1000 patient‐years (95% CI: 4.0–7.3). Most PTLDs were monomorphic (58.5%), or early lesions (21.5%). Excluding early lesions and patients <18 years, IR was 3.7 (95% CI: 2.9–5.5). Ten patients with PTLD were retransplanted, 2 developing further PTLDs. Post‐transplant patient survival was inferior in patients with PTLD, while death‐censored graft survival was not. Using registry data together with extensive pathological review and long follow‐up, a rather high incidence of PTLD was found.     

Campath induction in HCV and HCV/HIV‐seropositive kidney transplant recipients

Alemtuzumab (AZ) induction in hepatitis C‐seropositive (HCV+) kidney transplant (KTX) recipients may negatively affect patient survival; however, available information is scant. Using US registry data from 2003 to 2010 of adult HCV+ deceased‐donor KTXs (n = 4910), we examined outcomes by induction agent – AZ (n = 294), other T cell‐depleting agents, (n = 2033; T cell), IL‐2 receptor blockade (n = 1135; IL‐2RAb), and no induction (n = 1448). On multivariate analysis, induction therapy was associated with significantly better overall patient survival with AZ [adjusted hazards ratio (aHR) 0.64, 95% confidence interval (CI) 0.45, 0.92], T cell (aHR 0.52, 95% CI 0.41, 0.65) or IL‐2RAb (aHR 0.67, 95% CI 0.53, 0.87), compared to no induction. A significant protective effect was also seen with AZ (aHR 0.63, 95% CI 0.40, 0.99), T cell (aHR 0.62, 95% CI 0.49, 0.78), and IL2R‐Ab (aHR 0.62, 95% CI 0.47, 0.82) in terms of death‐censored graft survival relative to no induction. There were 88 HIV+/HCV+ coinfected recipients. Compared to noninduction, any induction (i.e. three induction groups combined) was associated with similar overall patient survival (P = 0.2255) on univariate analysis. Induction therapy with AZ, other T cell‐depleting agents, or IL‐2RAb in HCV+ KTX is associated with better patient and death‐censored graft survival compared to noninduction. In HCV/HIV coinfected patients, induction is not contraindicated.     

Similar frequency of Porcine circovirus 3 (PCV‐3) detection in serum samples of pigs affected by digestive or respiratory disorders and age‐matched clinically healthy pigs

Porcine circovirus 3 (PCV‐3) has been identified in pigs affected by different disease conditions, although its pathogenicity remains unclear. The objective of the present study was to assess the frequency of PCV‐3 infection in serum samples from animals suffering from post‐weaning respiratory or digestive disorders as well as in healthy animals. A total of 315 swine serum samples were analysed for PCV‐3 DNA detection by conventional PCR; positive samples were further assayed with a quantitative PCR and partially sequenced. Sera were obtained from 4 week‐ to 4 month‐old pigs clinically diagnosed with respiratory (n = 129) or digestive (n = 126) disorders. Serum samples of age‐matched healthy animals (n = 60) served as negative control. Pigs with clinical respiratory signs had a wide variety of pulmonary lesions including suppurative bronchopneumonia, interstitial pneumonia, fibrinous‐necrotizing pneumonia and/or pleuritis. Animals with enteric signs displayed histopathological findings like villus atrophy and fusion, catarrhal enteritis and/or catarrhal colitis. Overall, PCV‐3 DNA was detected in 19 out of 315 analysed samples (6.0%). Among the diseased animals, PCV‐3 was found in 6.2% (8 out of 129) and 5.6% (7 out of 126) of pigs with respiratory and digestive disorders, respectively. The frequency of PCV‐3 PCR positive samples among healthy pigs was 6.7% (4 out of 60). No apparent association was observed between PCR positive cases and any type of histopathological lesion. The phylogenetic analysis of the partial genome sequences obtained showed high identity among viruses from the three groups of animals studied. In conclusion, PCV‐3 was present in the serum of diseased and healthy pigs to similar percentages, suggesting that this virus does not seem to be causally associated with respiratory or enteric disorders.     

Efficacy and safety of prolonged‐release tacrolimus in stable pediatric allograft recipients converted from immediate‐release tacrolimus – a Phase 2, open‐label,single‐arm,one‐way crossover study

There are limited clinical data regarding prolonged‐release tacrolimus (PR‐T) use in pediatric transplant recipients. This Phase 2 study assessed the efficacy and safety of PR‐T in stable pediatric kidney, liver, and heart transplant recipients (aged ≥5 to ≤16 years) over 1 year following conversion from immediate‐release tacrolimus (IR‐T), on a 1:1 mg total‐daily‐dose basis. Endpoints included the incidence of acute rejection (AR), a composite endpoint of efficacy failure (death, graft loss, biopsy‐confirmed AR, and unknown outcome), and safety. Tacrolimus dose and whole‐blood trough levels (target 3.5–15 ng/ml) were also evaluated. Overall, 79 patients (kidney, n = 48; liver, n = 29; heart, n = 2) were assessed. Following conversion, tacrolimus dose and trough levels remained stable; however, 7.6–17.7% of patients across follow‐up visits had trough levels below the target range. Two (2.5%) patients had AR, and 3 (3.8%) had efficacy failure. No graft loss or deaths were reported. No new safety signals were identified. Drug‐related treatment‐emergent adverse events occurred in 28 patients (35.4%); most were mild, and all resolved. This study suggests that IR‐T to PR‐T conversion is effective and well tolerated over 1 year in pediatric transplant recipients and highlights the importance of therapeutic drug monitoring to maintain target tacrolimus trough levels.     

Post‐transplant lymphoproliferative disorder in adult liver transplant recipients: a South American multicenter experience

Post‐transplant lymphoproliferative disorder (PTLD) is a major and potentially life‐threatening complication after solid‐organ transplantation. The aim of this study was to describe the disease characteristics, clinical practices, and survival related to PTLD in adult orthotopic liver transplant (OLT) recipients in South America. We conducted a survey at four different transplant groups from Argentina, Brazil, and Chile. Among 1621 OLT recipients, 27 developed PTLD (1.7%); the mean age at diagnosis was 53.7 (±14) yr with a mean time of 39.7 (±35.2) months from OLT to PTLD diagnosis. Initial therapy included reduction in immunosuppression alone in 23.1% of the patients. Either rituximab or chemotherapy was employed as initial or second‐line therapy in 76.9% of the patients. PTLD location was frequently extranodal (80.7%) and mostly involving the transplanted liver (59.3%). The overall survival at one and five yr post‐PTLD diagnosis was 53.8% and 46.2%, respectively. Significant univariate risk factors for post‐PTLD mortality included lactate dehydrogenase ≥250 U/L (HR 9.66, p = 0.02), stage III/IV PTLD (HR 5.34, p = 0.004), and HCV infection (HR 7.68, p = 0.01). In conclusion, PTLD in OLT adult recipients is predominantly extranodal, and although mortality is high, long‐term survival is possible.