Lymphocyte subset at time of Epstein‐Barr viremia post‐allogeneic hematopoietic stem cell transplantation in children may predict development of post‐transplant lymphoproliferative disease: CD8:CD20 ratio as a sensitive predictor

EBV–associated PTLD following allogeneic HSCT is a serious complication associated with significant mortality. In this retrospective study, we evaluated whether lymphocyte subset numbers and CD8:CD20 ratio at time of EBV viremia in children undergoing allogeneic HSCT could predict development of PTLD. Absolute lymphocyte count, lymphocyte subsets, and CD8:CD20 ratio at the time of EBV viremia were analyzed. Patients who were treated preemptively with rituximab for high blood EBV viral load were excluded. Out of 266 patients transplanted during the study period, 26 patients were included in the analysis. Patients were divided into two cohorts; cohort 1 included patients with EBV‐associated PTLD (n = 5; four with proven, one with probable PTLD). Cohort 2 included patients with EBV viremia without PTLD (n = 21). Lymphocyte recovery was slower in the PTLD group. CD8:CD20 ratio was significantly lower in the PTLD group (median 0.15) compared to the non‐PTLD group (median 2.4, P = .012). Using the ROC curve and 1 as the cutoff value, CD8:CD20 ratios were analyzed. In the PTLD group, 4/5 patients (80%) had a ratio <1 whereas in the non‐PTLD group, all 21 patients had a ratio >1. Sensitivity and specificity were 80% and 100%, respectively. Negative and PPVs were 95% and 100%, respectively. Profoundly low T‐cell count and CD8:CD20 ratio may be used to predict development of PTLD in the context of EBV viremia in children post‐allogeneic HSCT. Further studies are needed to validate this finding.     

The incidence of autoimmune hemolytic anemia in pediatric hematopoietic stem cell recipients post‐first and post‐second hematopoietic stem cell transplant

The reported incidence of post‐allogeneic HSCT AIHA was between 4.4% and 6% following a single transplant. Cord blood transplantation, T‐cell depletion, and chronic GvHD are significantly associated with post‐transplant AIHA. During an 11‐yr period, data for 500 pediatric HSCT recipients were eligible for evaluation of the incidence of AIHA post‐first and post‐second transplants. Demographic, transplant, and post‐transplant‐related variables were analyzed. Twelve of 500 (2.4%) recipients at a median of 273 days and seven of 72 (9.7%) recipients at a median of 157 days developed AIHA post‐first and post‐second HSCT, respectively. Post‐first HSCT, none of the MRD recipients developed AIHA (0/175 MRD vs. 12/325 other donors, p = 0.04). Four of 12 required a second HSCT to control the AIHA. After the second HSCT, MUD was significantly associated with the development of AIHA. No other variables were associated with the post‐second transplant AIHA. The incidence of AIHA post‐first and post‐second HSCT was less than the reported. The increased incidence of AIHA among recipients of second HSCT is most likely due to the profound immune dysregulation. A much larger, prospective study would be needed to evaluate the incidence, complications, and management of post‐transplant AIHA.     

Epstein‐Barr viral load monitoring for diagnosing post‐transplant lymphoproliferative disorder in pediatric liver transplant recipients

This study aimed to investigate the incidence of PTLD in pediatric liver transplant recipients and the risk factors for the development of PTLD. We also determined clinically useful quantitative EBV PCR parameters for aiding in the diagnosis of EBV‐associated PTLD in the pediatric liver transplant recipients at our institute. We reviewed children < 18 years old who had undergone liver transplantations and quantitative analysis of whole blood EBV load at our institute from January 2006 to March 2015. A total of 142 liver transplant recipients were included, and their median age was 1.5 years. Clinically significant high‐level EBV DNAemia ≥ 10 000 copies/mL at least twice was observed in 53.5% and PTLD occurred in 9.9%. Among PTLD group, graft failure and mortality rate were as high as 21.4% and 14.3%, respectively. Deceased donor, presence of high‐level EBV DNAemia, and primary CMV infection following transplant were associated with an increased risk for PTLD in the multivariate analysis. The peak titer at 10 875 copies/mL could be used as a cutoff value with a sensitivity of 92.9% and a specificity of 37.9%; the rate of increase in EBV load suggested a sensitivity of 64.3% and a specificity of 70.9% at the cutoff value of 44 000 copies/mL/week. In conclusion, the incidence of PTLD following liver transplant in children was as high as 10%. PTLD is associated with significant morbidity and mortality. Close monitoring of EBV DNAemia is crucial for the early diagnosis and proper treatment of PTLD in pediatric liver transplant recipients.     

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.     

The role of allogeneic hematopoietic stem cell transplantation and Epstein‐Barr virus infection on the treatment for child primary hemophagocytic lymphohistiocytosis patients with X‐linked lymphoproliferative disease: A rare case report and family survey study

XLP‐2 is known as a rare primary immunodeficiency disease, which is characterized by the susceptibility to EBV infection and potential development into the pHLH. The existing studies believe that the dysfunction of XIAP represents one of the most significant pathogenic mechanisms of XLP‐2, and allo‐HSCT is regarded as a crucial treatment for the long‐term survival in XLP‐2 patients. In our present study, a 2‐year‐old male patient was diagnosed with XLP‐2. After receiving chemotherapy by using HLH‐2004 without allo‐HSCT, he reached a complete remission, and his EBV load was brought under control. Our family survey revealed a novel frameshift mutation in the XIAP gene in this patient, as well as in his cousin and grandfather. Until now, the patient has been followed up for 22 months with no recurrence reported yet. Based on these findings, it is believed that for child pHLH patients with XLP‐2, the treatment by controlling symptoms alone without allo‐HSCT and with regular monitoring of EBV load could be conducive to a long‐term survival.     

Bullous pemphigoid after allogeneic hematopoietic stem cell transplantation

Bullous pemphigoid (BP) is an autoimmune skin disorder characterized by subepidermal blisters due to deposit of autoantibody against dermal basement membrane protein. It has been reported that BP can occur after allogeneic hematopoietic stem cell transplantation (HSCT). We describe a patient with BP having autoantibody against BP180 after unrelated‐donor HSCT against T lymphoblastic leukemia. The patient was treated with steroid leading to complete resolution of BP, but T lymphoblastic leukemia progressed rapidly after steroid hormone treatment. Given that immunosuppressant may reduce graft‐versus‐tumor effect, immunomodulatory agents such as nicotinamide and tetracycline, erythromycin, and immunoglobulin may be appropriate as soon as typical blister lesions are seen after HSCT.     

Surveillance cultures in pediatric allogeneic hematopoietic stem cell transplantation

The value of surveillance cultures in predicting systemic infections and in guiding antimicrobial treatment is controversial. We investigated 57 pediatric allo‐SCTs between 2007 and 2009. ALL (34), AML (5), and severe aplastic anemia (4) were the largest patient groups. Conditioning was TBI‐based in 87% and 54% developed GVHD (21% grade III‐IV). Of the 2594 weekly colonization samples, 24% were positive (fecal bacteria 86%, fecal fungi 16%, Clostridium difficile 16%; throat bacteria 17% and throat fungi 4%). Enterobacteria and enterococci were the most common fecal findings, staphylococci and streptococci in the throat. Of the bacterial stool samples pretransplant, 74% (mostly enterococci) were resistant to our first‐line antibiotics (ceftazidime and cloxacillin). Candida species accounted for the majority of the fungal findings: 62% of the fecal and 78% in the throat. A total of 170 clinical infection episodes were recorded, and in 12 of these, the bacterial blood culture was positive. In 4/12 cases, the pathogen was detected in surveillance culture previously, leading to sensitivity and specificity of 33.3 and 47.4%, respectively. Positive predictive value of bacterial surveillance cultures was 0.9%. The antimicrobial treatment was changed in only five cases based on the surveillance culture results. Weekly surveillance cultures seldom provided clinical benefit and were not cost‐effective.     

儿童异基因造血干细胞移植后淋巴细胞增殖性疾病的临床研究

目的探讨儿童异基因造血干细胞移植（allo-HSCT）后淋巴细胞增殖性疾病（PTLD）的诊治及预后。方法回顾性分析4例allo-HSCT后EBV相关性PTLD（EBV．PTLD）患儿的临床资料。其中,急性淋巴细胞白血病（高危）（ALL—HR）2例,重型再生障碍性贫血（SAA）2例。异基因外周血造血干细胞移植（allo-PBSCT）3例,异基因脐血造血干细胞移植（allo-UCBSCT）1例。结果4例患儿分别于allo．HSCT后第53、101、22、42d发生PTLD。临床表现为发热、鼻塞、扁桃体肿大、淋巴结肿大和肝脾肿大,移植前均EBNA-1-IgG（＋）、VCA．IgG（＋）;移植后EBV．DNA1．69×10^4～8．62×10^8 copies／mL。经淋巴结病理活检确诊为EBV-PTLD,其中1例为T细胞来源,3例为B细胞来源。例1予减停免疫抑制剂、使用利妥昔单抗、联合COP方案化疗及供者淋巴细胞输注（DU）治疗,PTLD反复且发生严重皮肤GVHD、肺部感染,移植后第193d死亡。余3例予减停免疫抑制剂及利妥昔单抗治疗,临床表现消失且EBV．DNA转阴,分别随访17、12、7个月均无病存活。结论动态监测EBV—DNA对PTLD早期发现具有重要意义。减停免疫抑制剂联合利妥昔单抗治疗EBV-PTLD疗效明显。化疗可导致严重感染,DLI治疗存在严重GVHD危险,不宜作为一线治疗。     

Rotavirus‐associated hemophagocytic lymphohistiocytosis (HLH) after hematopoietic stem cell transplantation for familial HLH

Hemophagocytic lymphohistiocytosis (HLH) is a life‐threatening disorder of immune regulation. HLH consists of two forms: familial and acquired, the latter which occurs in association with infection, malignancy, rheumatic disease and acquired immune deficiency. Herein, we report a case of acquired HLH in a child who had received allogeneic hematopoietic stem cell transplantation for familial HLH with UNC13D mutation. Based on microbiology, only rotavirus was identified as a possible organism triggering HLH. The patient's fulminant clinical course included acute respiratory failure, a sepsis‐like pattern, disseminated intravascular coagulopathy, and rhabdomyolysis, leading to multiorgan failure and death from septic shock.     

Favorable outcome with allogeneic hematopoietic stem cell transplantation in pediatric acquired aplastic anemia patients

The data of allogeneic HSCT in nine children with acquired AA between June 1998 and July 2006 were analyzed retrospectively. The median duration of time to neutrophil and platelet engraftment was 18 and 25 days, respectively. None of the patients had primary graft failure. Two (22.2%) patients developed acute GVHD and of these, one (11.1%) was Grade 1, and the other (11.1%) was Grade 3. Although the study group was composed of higher risk patients, including six of nine resistant to previous immunosuppressive treatment, eight had multiple not irradiated or filtered transfusion histories and one of the cases was only 5/6 HLA-compatible with his donor, the five-yr overall and EFS was 100%, and all recipients are alive without any graft failure. This may be attributed to the dose adjusted use of ATG according to individual transfusion history and gradual tapering of CsA and cessation at least nine months after allogeneic HSCT.     

Proven Epstein–Barr encephalitis with negative EBV‐DNA load in cerebrospinal fluid after allogeneic hematopoietic stem cell transplantation in a child with acute lymphoblastic leukemia

We report a case of EBV encephalitis in a seven‐yr‐old child with Ph+ ALL. Two months after an allogeneic HSCT from his HLA mismatched mother, the patient showed an altered sensorium, generalized seizures, and a left hemiparesis. Brain MRI demonstrated multiple lesions highly suggestive for viral encephalitis. Blood and CSF PCR analyses were negative for the most common viruses involved in immunocompromised patients including EBV. A cerebral biopsy was performed, which showed intense gliosis and perivascular lymphocytic cuffing. PCR analysis performed on brain tissue was positive only for the EBV genome, while extensive investigations for other viral infections were negative. The patient's neurological symptoms rapidly worsened and he died two months later. This case report suggests that in patients presenting neurological and radiological signs of encephalitis after an HSCT, an EBV involvement should be considered, even in the absence of CSF and blood PCR virus detection.     

Intravesical cidofovir to treat BK virus‐associated hemorrhagic cystitis in children after hematopoietic stem cell transplantation

HC related to BK virus replication might be a severe complication following allogeneic HSCT. There are no clearly defined treatment guidelines in pediatric population. The data on the effectiveness of ICI to manage severe bleeding in children are very limited. We report our experience of intravesical cidofovir in four children, 6–15 yr of age, to manage grade III–IV BK virus‐associated HC. Three of four children had high CSA serum level prior to developing cystitis. Intravesical instillations of cidofovir resulted only in temporal relief of bleeding. After immune suppression was withdrawn or tapered, intravesical instillations of formalin solution had to be undertaken to abort severe bleeding. We concluded that intravesical cidofovir alone did not appear to be sufficiently effective in case of severe HC, necessitating complimentary procedures to stop macrohematuria.     

The outcome of hematopoietic stem cell transplantation in Korean children with hemophagocytic lymphohistiocytosis

Yoon HS, Im HJ, Moon HN, Lee JH, Kim H‐J, Yoo KH, Sung KW, Koo HH, Kang HJ, Shin HY, Ahn HS, Cho B, Kim HK, Lyu CJ, Lee MJ, Kook H, Hwang TJ, Seo JJ. The outcome of hematopoietic stem cell transplantation in Korean children with hemophagocytic lymphohistiocytosis.
Pediatr Transplantation 2010: 14:735–740. © 2010 John Wiley & Sons A/S. Abstract: Chemoimmunotherapy‐based treatments have improved the survival of patients with HLH, but outcomes of the patients are still unsatisfactory. We report here the outcome of Korean children with HLH who underwent HSCT, which was analyzed from the data of a nation‐wide HLH registry. Retrospective nation‐wide data recruitment for the pediatric HLH patients diagnosed between 1996 and 2008 was carried out by the Histiocytosis Working Party of the Korean Society of Hematology. Nineteen patients who received HSCT among the total of 148 enrolled children with HLH were analyzed for the transplant‐related variables and events. The probability of five‐yr survival after HSCT was 73.3% with a median follow‐up of 57. Two months compared to 54.3% for the patients who were treated with chemoimmunotherapy only (p = 0.05). The reasons for HSCT were active disease after eight wk of initial treatment (n = 9), relapsed disease (n = 5), and FHL (n = 5). Fourteen patients are currently alive without disease after HSCT, four patients died of treatment‐related events (infection in two and graft failure in two) at early post‐transplant period, and one patient died of relapse at one yr post transplantation. The survival of patients who were transplanted because of active disease after eight wk of initial treatment was worse compared to those patients who had inactive state at that time (60.6% vs. 100%, respectively, p = 0.06). Of the four patients who received transplants using cord blood, three died of graft failure (n = 2) and relapse (n = 1). The five‐yr probability of survival after HSCT according to the donor type was 85.7% for the MRDs (n = 6), 87.5% for the MUDs (n = 8), and 40% for the MMUDs (n = 5) (p = 0.03). Other variables such as age, CNS involvement at the time of diagnosis, the etiology of HLH (familial or secondary), and the conditioning regimens had no influence on the five‐yr OS of the HLH patients who underwent HSCT. HSCT improved the survival of the patients who had familial, relapsed, or severe and persistent SHLH in the Korean nation‐wide HLH registry. Although numbers were small, these results are similar to other reports in the literature. The disease state after initial treatment, the stem cell source of the transplant, and the donor type were the important prognostic factors that affected the OS of the HLH patients who underwent HSCT.     

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.