Polyomavirus infection in pediatric renal transplant recipients: evaluation using a quantitative real-time PCR technique

Polyomavirus infection and related nephropathy is being increasingly recognized as an important cause of allograft dysfunction in adult renal transplant recipients. We prospectively monitored pediatric renal transplant recipients for the presence of BK and JC polyomavirus in urine and blood using a quantitative PCR assay to evaluate the prevalence and clinical relevance of polyomavirus infection in the pediatric renal transplant population. Of 46 pediatric renal recipients who were evaluated, nine (20%) demonstrated isolated BKV viruria, while five (11%) had concomitant BKV viremia and viruria. JCV viruria was found in eight (17%) patients. BKV viremia was associated with a significantly higher urinary BKV viral load: median urinary viral load 1.9 x 10(9) copies/mL (range 6.7 x 10(2)-1.8 x 10(11)) for the group with concomitant viremia and viruria vs. 1.8 x 10(3) copies/mL (range 2.5 x 10(2)-4.5 x 10(6)) for the group with isolated viruria (p < 0.0001). In children that were followed prospectively since their transplantation, the BKV urinary viral load increased markedly before viremia became detectable a few weeks later. None of the patients with JCV viruria or isolated BKV viruria had renal dysfunction. Among the five patients with BKV in both urine and blood, two developed biopsy-proven BKV nephropathy associated with deterioration of the renal function. Management of the BKV nephropathy consisted of reduction of immunosuppression alone or in combination with antiviral treatment with cidofovir. This study shows that polyomavirus infection and related interstitial nephritis is a relevant clinical issue in the pediatric renal transplant population. Monitoring the polyomaviral load in the urine and the blood of the patients using a quantitative PCR technique is a useful tool in the diagnosis and subsequent management of this infection. Even before viremia is present, an important rise in the urinary viral load should draw the attention of the transplant clinician and raise the issue of adapting the immunosuppression.     

Quantiferon‐Cytomegalovirus assay: A potentially useful tool in the evaluation of CMV‐specific CD8+ T‐cell reconstitution in pediatric hematopoietic stem cell transplant patients

Pediatric HSCT recipients are at high risk for CMV reactivation due to their immature immune system and therapy following transplantation. Reconstitution of CMV‐specific T‐cell immunity is associated with control and protection against CMV. The clinical utility of monitoring CMV‐specific CMI to predict CMV viremia in pediatric HSCT patients using the Quantiferon‐CMV (QIAGEN^®) test was investigated prospectively. Thirty‐seven pediatric allogeneic HSCT recipients were enrolled from 3/2010‐6/2012. CMV viremia was detected via weekly real‐time PCR. The Quantiferon‐CMV test was conducted pretransplant, early after transplantation, 30, 90 , 180 , 270, and 360 days post‐transplantation. The incidence of CMV viremia was 51% (19/37) with half of the episodes within ≤30 days post‐transplant. Fifteen patients showed CMV‐specific immunity (average of 82 days). The cumulative incidence of CMV reactivation in patients who developed CMV‐specific immunity was lower than those who did not (15% vs 53%; P = .023). The ROC statistical analysis showed that the AUC was 0.725 in predicting viremia, for Quantiferon‐CMV test. In this cohort, the Quantiferon‐CMV assay was a valuable method for identifying pediatric HSCT patients at high risk for CMV viremia, suggesting potential clinical utility to individualize patient's management post‐transplant.     

Pretransplant IgG antibodies to polyoma BK virus in pediatric renal transplants

Bijol V, Cimic A, Viscidi RP, Hymes LC. Pretransplant IgG antibodies to polyoma BK virus in pediatric renal transplants.
Pediatr Transplantation 2010:14:224–227. © 2009 John Wiley & Sons A/S. Abstract: We retrospectively measured IgG antibody levels to BKV in pretransplant sera and compared levels in children who developed BK viremia to a control group who remained free of infection after transplantation. Sera from 45 renal transplant patients were available for analysis (BK viremia = 23, controls = 22). Serum BKV PCR levels ranged from 3400 to 6.5 million DNA copies/mL (mean ± s.d.: 978K ± 1.77 million) and were highest in patients with BK nephritis (p = 0.007). Overall, 35% of children with BK viremia were BKV‐seronegative vs. 9% of children in control group (p = 0.04), but mean antibody levels were similar between viremic and control patients (p = 0.15). However, children who developed viremia later than six months post‐transplantation had significantly lower antibody levels compared with controls (p = 0.004) and patients with early viremia (p = 0.007), and may represent de novo infection or reinfection, rather than recurrence of latent infection. Pretransplant antibody status was significantly associated with subsequent development of BK viremia. Although our findings identified possible factors for developing BK viremia, there was sufficient overlap of both seropositive status and antibody levels among viremic patients and the control group to question the clinical utility of pretransplant IgG antibodies.     

Pretransplant serologic testing to identify the risk of polyoma BK viremia in pediatric kidney transplant recipients

This study investigated the age-related prevalence of a prior polyoma BKV infection at the time of transplantation and association with subsequent development of BKV viremia. We measured BKV-specific antibody titers in stored serum samples obtained before transplantation in 94 pediatric kidney transplant recipients (in a single-center, retrospective analysis) and 40 matched donors from 1986 to 2007. Titers were categorized as LOW or HIGH serostatus at titers of ≤ 1:2560 and ≥ 1:10 240, respectively. Of these, 36 recipients transplanted since 2002 were prospectively screened for BKV viremia. Seventeen percent of recipients aged 0-6 yr had HIGH BKV serostatus compared with 73% of older recipients (p < 0.002). The prevalence of HIGH donor BKV serostatus was 73%. Five prospectively screened patients (14%) developed early BKV viremia, and an additional 4 (11%) had late onset of BKV viremia. There were three cases (8%) of BKVAN. LOW BKV serostatus was significantly associated with early BKV viremia (p = 0.02). Donor HIGH to recipient LOW (HIGH/LOW) had the highest risk of BKV viremia (4/7; 57%), compared with LOW/LOW (0/3; 0%) and recipient HIGH (1/26; 4%) (p = 0.004). BKV IgG titers are low in young pediatric kidney transplant recipients, and LOW BKV serostatus is associated with an increased risk of early BKV infection post-transplant, particularly in the context of donor with HIGH BKV serostatus.     

The impact of alternative donor types on viral infections in pediatric hematopoietic stem cell transplantation

Viral infections remain one of the most important complications following allogeneic HSCT. Few reports compare virus infection between different donor types in pediatric patients. We retrospectively analyzed viral infections and the outcome of one hundred and seventy‐one pediatric patients (median 7.38 years) who underwent allogeneic HSCT from matched related donor (MRD, n = 71), 10 of 10 HLA allele‐matched unrelated donors (MUD1; n = 29), 9 of 10 HLA allele‐matched unrelated donors (MUD2; n = 40), and haploidentical donors (n = 31). PCR screening for BK virus, adenovirus, Epstein‐Barr virus, parvovirus B19, human herpesvirus 6, and CMV were performed routinely weekly. Infections between 0‐30, 31‐100, and 101 days‐2 years were identified separately. BK virus and CMV reactivations were significantly low in MRD transplant patients (P = .046 and P < .0001, respectively), but incidences of all virus infections between MUD1, MUD2, and haplo‐HSCT were found statistically not different. The OS was found to be affected by having one or multiple virus infection (P = .04 and P = .0008). Despite antiviral prophylaxis and treatments, post‐transplant viral infections are associated with reduced overall survival. Haplo‐HSCT is comparable with MUD transplantation in the setting of viral infections. A larger study group and prospective studies are needed to confirm this observation.     

The impact of recipient BKV shedding before transplant on BKV viruria,DNAemia, and nephropathy post‐transplant: A prospective study

We previously demonstrated that detectable BKV replication in donor urine pretransplant was significantly associated with post‐transplant recipient BKV viremia. In this 4‐year prospective study, we assessed whether recipient BKV replication pretransplant was associated with post‐transplant viremia/BKV nephropathy. We studied 220 primary adult and pediatric organ transplant recipients for 490 person‐years and 2100 clinical visits. BKV viruria was detectable in 28 (16%), 26 adults and two children; and viremia in none pretransplant. Post‐transplant viruria occurred in all recipients with pretransplant BKV viruria, significantly more than in recipients without pretransplant viruria on univariate (P<.005) and multivariate analysis including type of organ transplanted and immunosuppression type (P .008). Time to post‐transplant viruria was significantly shorter in recipients with pretransplant viruria (P .01). By univariate and multivariate analysis, BKV viruria in recipients pretransplant did not impact post‐transplant BKV viremia (P=.97 and .97, respectively) even when stratified by type of organ transplant (kidney P=.6; liver P=.5). The peak serum and urine BKV PCR post‐transplant were not significantly different in patients with pretransplant BKV viruria and no one developed BK nephropathy. In conclusion, recipient BKV viruria prior to transplant predicts post‐transplant viruria but not viremia or BKV nephropathy.     

Cross-sectional study of BK virus infection in pediatric kidney transplant recipients

BKV reactivation is associated with impaired graft function in adult kidney transplant patients. The clinical impact of BKV infection in the pediatric transplant population has not yet been fully evaluated. The objective of our study was to determine the prevalence of BKV infection in consecutive pediatric kidney transplant recipients in our center. Forty consecutive unselected pediatric kidney transplant recipients were studied. Mean age at screening was 15.6 +/- 5.3 yr and samples were obtained a median of 60.5 months after transplantation (3-123). BKV-DNA was analyzed in urine and plasma by qualitative nested-PCR. A review of the literature was performed. Prevalence of viruria and viremia was 50% and 12.5%, respectively. Viremia was associated with the presence of hematuria (p = 0.02). The mean creatinine level in children without BKV replication was 1.6 mg/dL, BKV viruria was 0.9 mg/dL, and BKV viremia was 0.8 mg/dL. A literature review showed that viruria and viremia were found in 28.2% and 8.5% of cases, respectively; BKV nephropathy was found in 3.8% and graft loss in 11% of the patients with BKV nephropathy and in 0.4% of the children studied. Recipient serostatus was the most important risk factor. The rate of BKV replication and nephropathy among pediatric kidney recipients is similar to that of adults, but the incidence of graft loss is significantly lower.     

Human herpesvirus‐6 viremia is not associated with poor clinical outcomes in children following allogeneic hematopoietic cell transplantation

HHV‐6 is an evolving pathogen in the field of AlloHCT. However, the impact of HHV‐6 on AlloHCT outcomes remains to be elucidated. We studied the incidence and clinical impact of HHV‐6 viremia in children following AlloHCT. One hundred consecutive children were monitored weekly by plasma PCR for the first 180 days following AlloHCT for HHV‐6, CMV, EBV, and ADV. HHV‐6 viremia was defined as plasma PCR >1000 viral copies/mL. The median age was nine yr. Following AlloHCT, 19% (95% CI 11.3–26.7%) of patients had HHV‐6 viremia, with the highest incidence of reactivation (14/19, 73%) occurring during day +15‐day +98. The proportion of platelet engraftment by day +180 was lower in patients with HHV‐6 viremia (58%) than in those without HHV‐6 viremia (82%), p = 0.028. Delay in neutrophil and platelet engraftment was not associated with HHV‐6 viremia in multivariate analysis. Similarly, HHV‐6 viremia was not associated with TRM in multivariate analysis (p = 0.15). In summary, HHV‐6 viremia is prevalent in pediatric AlloHCT recipients. Based on our study results, we recommend that HHV‐6 PCR should only be performed on clinical suspicion.     

Multiple viral infections post‐hematopoietic stem cell transplantation are linked to the appearance of chronic GVHD among pediatric recipients of allogeneic grafts

Olkinuora HA, Taskinen MH, Saarinen‐Pihkala UM, Vettenranta KK. Multiple viral infections post‐hematopoietic stem cell transplantation are linked to the appearance of chronic GVHD among pediatric recipients of allogeneic grafts.
Pediatr Transplantation 2010:14:242–248. © 2009 John Wiley & Sons A/S. Abstract: Delayed immune reconstitution and the ensuing opportunistic infections among children following hematopoietic stem cell transplantation (HSCT) are associated with increased treatment‐related morbidity and mortality (TRM). We retrospectively evaluated the impact of viral infections on the posttransplant recovery of pediatric recipients of stem cell grafts as a reflection of their posttransplant immunoreconstitution in a single institution setting. The case histories of 124 children (during 1/1999‐9/2006) were reviewed for infectious episodes, and correlated with their respective clinical parameters. Patients with a high risk for CMV received prophylaxis, but failures in the prophylaxis were common (40%). 110/124 (89%) of these allogeneic patients had at least one viral reactivation/clinical infection posttransplant. In this group of pediatric patients chronic GVHD (P<0,001) and secondary graft failure were significantly (P=0,001) associated with early (during the first 100 days post HSCT), multiple (≥ 2) viral infections. Our data indicate that viruses are common pathogens among pediatric recipients of allogeneic stem cell grafts. In this group of patients multiple viral infections early on seem to reflect an even more severe degree of immunological derangement in the recipient and identify a group of patients with an increased risk of chronic GVHD and secondary graft failure.     

Subclinical cytomegalovirus and Epstein-Barr virus viremia are associated with adverse outcomes in pediatric renal transplantation

Post-transplant clinical disease with cytomegalovirus (CMV) and Epstein-Barr virus (EBV) is a known risk factor for graft dysfunction and lymphoproliferation. We postulate that subclinical, asymptomatic viremia also adversely impacts outcomes, and may warrant re-assessment of current monitoring and antiviral prophylaxis protocols. A single-center study was conducted on 102 pediatric (51 steroid-free and 51 matched steroid-based historical controls). Quantitative viral loads were serially monitored and correlated with outcome measures. Overall, the incidence of CMV and EBV clinical disease was 5% (1% CMV and 4% EBV); however, the incidence of subclinical viremia was 44% (12.7% CMV, 38.2% EBV, 6.9% CMV + EBV). Risk factors for subclinical viremia were EBV naivety (p = 0.07), age less than five yr (p = 0.04), lack of prophylaxis (p = 0.01), and steroid usage (p = 0.0007). Subclinical viremia was associated with lower three-yr graft function (p = 0.03), increased risk of acute rejection (odds ratio 2.07; p = 0.025), hypertension (p = 0.04), and graft loss (p = 0.03). Subclinical asymptomatic CMV and EBV viremia is a risk factor for graft injury and loss. These findings support the need for aggressive, serial viral monitoring to better determine the appropriate length of post-transplant antiviral prophylaxis, and to determine the effect of immunosuppression protocols on the development of viremia.     

Unusual presentations of BK virus infections in pediatric renal transplant recipients

BKV has emerged as a significant pathogen in the field of transplantation, predominantly causing BKV nephropathy in renal transplant recipients and hemorrhagic cystitis in HSCT recipients. However, case reports describe more diverse complications, and we too present three unusual cases of BKV infections in pediatric renal transplant recipients. First, we describe a case of biopsy‐proven renal damage secondary to BKV prior to the onset of viremia, demonstrating that BKV nephropathy can occur without preceding viremia. We also present two renal transplant recipients with persistent BK viruria, one with BKV‐associated hemorrhagic cystitis and the other with microscopic hematuria. Therefore, we conclude that BKV manifestations may be more diverse than previously thought and suggest clinical utility in urine BKV qPCR testing in specific transplant recipients.     

Correlation and clinical utility of pp65 antigenemia and quantitative polymerase chain reaction assays for detection of cytomegalovirus in pediatric renal transplant patients

Rha B, Redden D, Benfield M, Lakeman F, Whitley RJ, Shimamura M. Correlation and clinical utility of pp65 antigenemia and quantitative polymerase chain reaction assays for detection of cytomegalovirus in pediatric renal transplant patients. Abstract:  qPCR and pp65 antigenemia assays are used to monitor CMV infection in renal transplant recipients, but correlation of assays in a pediatric population has not been evaluated. Paired CMV real‐time qPCR and pp65 antigenemia tests from 882 blood samples collected from 115 pediatric renal transplant recipients were analyzed in this retrospective cohort study for the strength of association and clinical correlates. The assays correlated well in detecting infection (κ = 0.61). Higher qPCR values were demonstrated with increasing levels of antigenemia (p < 0.01). Discordant test results were associated with antiviral treatment (OR 4.33, p < 0.01) and low‐level viremia, with odds of concordance increasing at higher qPCR values (OR 3.67, p < 0.01), and no discordance occurring above 8500 genomic equivalents/mL. Among discordant samples, neither test preceded the other in detecting initial infection or in returning to negative while on treatment. Only two cases of disease occurred during the two‐yr study period. With strong agreement in the detection of CMV infection, either qPCR or pp65 antigenemia assays can be used effectively for monitoring pediatric renal transplant patients for both detection and resolution of infection.     

BK polyomavirus infection in pediatric heart transplant recipients: a prospective study

BKV infection and nephropathy complicate pediatric HTx, but the incidence and time course of the disease are unknown. We assessed the incidence of BKV infection and its association with kidney dysfunction in pediatric HTx recipients. A single center prospective study compared pediatric (<18 years) HTx recipients, with and without BKV infection, who received an allograft between September 2013 and December 2014. Screening of urine for BKV was performed prior to transplant, and at week 1, and at months 3, 6, 9, 12, and 15 months post‐transplantation. Serum for BKV DNA was assayed if BK viruria was present. Statistics included Fisher's exact test and Student's t test. Twelve patients were enrolled. Two patients were removed per parent request. Two (20%) had BK viruria and one (10%) had BK viremia. No patients developed BKVN. BK viruria was present within 2 months following transplantation. There were no identifiable risk factors for BKV infection and no statistically significant difference in renal function between the groups; however, there was a trend toward worsening renal function in those with BKV infection. BKV infection can occur early following heart transplantation. Screening for BK viruria should be considered in HTx recipients.     

Intravenous immunoglobulin therapy in the treatment of BK viremia and nephropathy in pediatric renal transplant recipients

Anyaegbu EI, Almond PS, Milligan T, Allen WR, Gharaybeh S, Al‐Akash SI. Intravenous immunoglobulin therapy in the treatment of BK viremia and nephropathy in pediatric renal transplant recipients.
Pediatr Transplantation 2012: 16: E19–E24. © 2010 John Wiley & Sons A/S. Abstract: Polyoma BKVN is a significant cause of allograft dysfunction and loss in renal transplant recipients. Reduction in immunosuppression is accepted as first‐line therapy to decrease viral load and prevent allograft injury and dysfunction. We report our experience with persistent BKV after reduction in immunosuppression followed by successful clearance of BKV in three pediatric renal transplant recipients and histological resolution of BKVN in a fourth patient following therapy with IVIG. Once BKV was detected, immunosuppression was reduced and BKV was monitored until clearance was achieved. All four patients were given IVIG in a dose of 2 g/kg. Allograft function remained stable in all patients. Early routine screening for BKV allows early intervention to prevent the development of BKVN and permanent allograft damage. While immunosuppression reduction is a logical first‐line therapy, second‐line therapy is not well established. IVIG seems to be an effective treatment for persistent BKV after reduction in immunosuppression and for BKVN and can therefore be considered as a therapeutic option in these patients.     

High incidence of BK virus‐associated hemorrhagic cystitis in children after second or third allogeneic hematopoietic stem cell transplantation

BKV‐HC is a serious complication of allogeneic HSCT. To characterize the incidence, risk factors, and clinical outcomes of post‐HSCT BKV‐HC, we retrospectively analyzed 112 patients who underwent one or more allogeneic HSCTs at our hospital between 2001 and 2017. Twenty underwent second or third HSCT thereafter. Ten patients developed BKV‐HC at a median of 30 days after HSCT. The 100‐day cumulative incidences of grade 0‐4 and grade 2‐4 BKV‐HC were 7.8% and 6.2%, respectively. HSCTs performed in 2011‐2017 associated with significantly higher 100‐day cumulative incidence of grade 2‐4 BKV‐HC (14.0%) than HSCTs performed in 2001‐2010 (1.3%, P = 0.004). On multivariate analysis, second or third HSCT was the only independent significant risk factor for development of grade 2‐4 BKV‐HC (P = 0.015). Serial PCR monitoring of urine and blood BKV load did not predict BKV‐HC. The recent increase in the incidence of BKV‐HC may reflect recent innovations in transplant technologies that facilitate second or third HSCT, which are known to cause prolonged immune deficiency. If safe and effective treatment or prophylaxis becomes available, it could be used to target the high‐risk patients for BKV‐HC.     

Polyomaviruses BK,JC, KI,WU, MC,and TS in children with allogeneic hematopoietic stem cell transplantation

Timely and reliable detection of viruses is of key importance in early diagnosis of infection(s) following allogeneic HSCT. Among the immunocompetent, infections with BKPyV and JCPyV are mostly subclinical, while post‐HSCT, the former may cause HC and the latter PML. The epidemiology and clinical impact of the newly identified KIPyV, WUPyV, MCPyV, and TSPyV in this context remain to be defined. To assess the incidence and clinical impact of BKPyV, JCPyV, KIPyV, WUPyV, MCPyV, and TSPyV infections, we performed longitudinal molecular surveillance for DNAemias of these HPyVs among 53 pediatric HSCT recipients. Surveillance pre‐HSCT and for three months post‐HSCT revealed BKPyV DNAemia in 20 (38%) patients. Our data demonstrate frequent BKPyV DNAemia among pediatric patients with HSCT and the confinement of clinical symptoms to high copy numbers alone. MCPyV and JCPyV viremias occurred at low and TSPyV viremia at very low prevalences. KIPyV or WUPyV viremias were not demonstrable in this group of immunocompromised patients.     

Outcome of management strategies for BK virus replication in pediatric renal transplant recipients

Abstract:  Management of BKV infection is not well defined. Eighteen pediatric renal transplant patients with BKV-PCR (+) were divided into three groups; Group 1: Viruria only (6), Group 2: Viremia with stable GFR (4), Group 3: Viremia with >25% decline in GFR and BKVAN on biopsy (8). With initial BKV-PCR(+), Group 1 received no treatment; Group 2 had MMF reduced 30%; Group 3: 6/8 had CNI discontinuation, 2/8 had reduced MMF and cidofovir. BKV, GFR and histology were compared pre- and post-treatment. In Group 1 viruria decreased in all patients; GFR remained stable. Group 2 showed reduced viremia with no GFR change. Group 3 showed reduced viremia in 8/8 patients. Patients with >50% decline in GFR from baseline (6/8) showed worse histology: 2/6 lost grafts despite no BKV on follow-up biopsy. Our results show that with viruria alone no treatment is necessary; with viremia and stable GFR, reduced immunosuppression decreases viremia and maintains GFR. With viremia and reduced GFR, immunosuppression reduction with or without cidofovir decreases viremia and stabilizes GFR in most patients. Greater than 50% reduction in GFR at BKVAN diagnosis correlates with risk for graft loss. Serial monitoring of BKV viremia with early intervention may prevent BKVAN graft loss in children.     

Cytomegalovirus infection in children who underwent hematopoietic stem cell transplantation at a single center: A retrospective study of the risk factors

Abstract:  CMV infection is one of the major causes of morbidity and mortality after HSCT. The aim of this single center retrospective study was to analyze risk factors for CMV infection in pediatric patients who underwent HSCT. We retrospectively reviewed the medical records of 117 pediatric patients who underwent allogeneic HSCT at Asan Medical Center between December 2000 and January 2007. After HSCT, CMV antigenemia was detected by identifying CMV pp65 early antigen in white blood cells. The incidence of CMV antigenemia was 24% (28/117) at a median of 38 days (range: 19–123 days) after HSCT. In multivariate analysis, CMV antigenemia occurred significantly more often in CMV seropositive recipients, patients who received grafts from alternative donors, T-cell depleted grafts, patients on ATG-containing conditioning regimens, or patients who received steroid for acute GVHD (p < 0.05). CMV antigenemia tend to develop earlier in patients who received ATG-containing conditioning regimens (p = 0.09). A second episode of CMV antigenemia was observed in three out of 28 patients (11%). The incidence of CMV disease was 5.9% (7/117) at a median of 97 days (range: 34–120 days). Manifestation of CMV disease included retinitis in two, pneumonitis in two, hepatitis in one, hepatitis with colitis in one, and gastritis in one. Six of the 12 patients (50%) with HG antigenemia (CMV pp65 antigen positivity ≥40 cells) developed clinical CMV disease, a rate that was significantly higher than seen in patients with LG antigenemia (6.25%; p < 0.01). We recommend that patients with these risk factors should carefully undergo regular evaluations for CMV infection. We also suggest that earlier and more aggressive preemptive treatment and serial follow-up of CMV disease is necessary in patients with HG-antigenemia.     

Safety and efficacy of prolonged cytomegalovirus prophylaxis with intravenous ganciclovir in pediatric and young adult lung transplant recipients

CMV infection causes morbidity and mortality after transplantation. Despite a wide range of prevention strategies among pediatric lung transplant programs, the optimal duration of prophylactic therapy against CMV infection in pediatric lung transplantation is unknown. To assess the feasibility, safety, and short-term efficacy of extending intravenous ganciclovir administration from six wk duration to 12 wk duration in pediatric lung transplant recipients. An open-label pilot study was performed in primary pediatric lung transplant recipients with donor and/or recipient CMV seropositivity. Intravenous ganciclovir was given for 12 wk post-transplantation. Subjects were tracked for protocol completion. Toxicities monitored included renal dysfunction, myelosuppression, gastrointestinal and neurological complications, as well as infection related to indwelling catheter placement. Serial CMV levels were measured to determine short-term efficacy of the intervention. Nine of nine subjects enrolled completed the pilot study. Subjects' ages ranged from six to 18 yr. Indications for lung transplantation included cystic fibrosis (n = 7), idiopathic pulmonary hypertension (n = 1), and complex congenital heart disease with pulmonary hypertension (n = 1). Seven subjects underwent deceased donor bilateral lung transplantation and two subjects underwent heart-lung transplantation. No subjects had protocol-defined drug toxicity. No episodes of neutropenia, thrombocytopenia, or renal toxicity occurred. Five subjects had catheter-related infections (three after week 12 of ganciclovir). Seven of nine subjects had CMV detected by PCR (four prior to ganciclovir completion) with only one subject having a positive viral culture for CMV viremia (prior to ganciclovir completion). No subjects had UL-97 mutation for ganciclovir resistance detected. The use of prolonged prophylactic administration of ganciclovir for 12 wk duration is a feasible, safe, and effective treatment to prevent CMV viremia based on viral culture in at risk pediatric lung transplant recipients. Further clinical studies are underway to determine optimal CMV prevention strategies.     

Cytomegalovirus viremia and resistance patterns in immunocompromised children: An 11-year experience

Abstract

We noted a recent increase in number of immunocompromised children with CMV viremia at our institution. The purpose of this study was to determine the frequency of CMV viremia in this population and evaluate factors associated with drug-resistant mutations. A retrospective review of immunocompromised hosts, 0–21?years of age, who had CMV viremia during 2007–2017. CMV viremia was detected using PCR assays. Genetic mutation assays were performed using PCR sequencing of the phosophotransferase UL 97 gene and the polymerase UL54 gene of CMV using Quest Diagnostics (San Juan Capistrano, CA, USA) or ARUP Labs (Salt Lake City, UT, USA). Thirty-one patients were identified, including 10 (32%) during the last 2?years. Of the 31 patients, 18 had hematopoietic stem cell transplantation (HSCT), 5 had primary immunodeficiency, 4 had malignancies, 3 had heart transplantation and 1 had new Human Immunodeficiency virus (HIV) infection. Antiviral resistance testing was performed on isolates from seven patients: five with persistent viremia (>1?mo), and two prior to starting antiviral therapy. Resistance was identified in three patients’ isolates: two with common variable immunodeficiency (CVID) and one with recurrent Hodgkin’s lymphoma who had undergone autologous HSCT. The two patients with CVID had chronic diarrhea and malabsorption and had received prolonged oral valganciclovir courses prior to emergence of resistance. The patient with Hodgkin’s lymphoma had received a prolonged IV ganciclovir course. All three tested positive for UL97 mutation and two had both UL97 and UL54 gene mutations. Majority of our patients (21/31) with CMV viremia were transplant recipients and ganciclovir resistance developed in 10%. Two had intestinal malabsorption. Treatment with oral valganciclovir should be avoided in patients with poor gut absorption as that may increase the risk of resistance.