COVID-19 disease in children and adolescents following allogeneic hematopoietic stem cell transplantation: A report from the Turkish pediatric bone marrow transplantation study group

BACKGROUND

Data on the risk factors and outcomes for pediatric patients with SARS-CoV-2 infection (COVID-19) following hematopoietic stem cell transplantation (HSCT) are limited.

OBJECTIVES

The study aimed to analyze the clinical signs, risk factors, and outcomes for ICU admission and mortality in a large pediatric cohort who underwent allogeneic HSCT prior to COVID-19 infection.

METHOD

In this nationwide study, we retrospectively reviewed the data of 184 pediatric HSCT recipients who had COVID-19 between March 2020 and August 2022.

RESULTS

The median time from HSCT to COVID-19 infection was 209.0 days (IQR, 111.7-340.8; range, 0-3845 days). The most common clinical manifestation was fever (58.7%). While most patients (78.8%) had asymptomatic/mild disease, the disease severity was moderate in 9.2% and severe and critical in 4.4% and 7.6%, respectively. The overall mortality was 10.9% (n: 20). Deaths were attributable to COVID-19 in nine (4.9%) patients. Multivariate analysis revealed that lower respiratory tract disease (LRTD) (OR, 23.20, p: .001) and lymphopenia at diagnosis (OR, 5.21, p: .006) were risk factors for ICU admission and that HSCT from a mismatched donor (OR, 54.04, p: .028), multisystem inflammatory syndrome in children (MIS-C) (OR, 31.07, p: .003), and LRTD (OR, 10.11, p: .035) were associated with a higher risk for COVID-19-related mortality.

CONCLUSION

While COVID-19 is mostly asymptomatic or mild in pediatric transplant recipients, it can cause ICU admission in those with LRTD or lymphopenia at diagnosis and may be more fatal in those who are transplanted from a mismatched donor and those who develop MIS-C or LRTD.

Myeloid sarcoma with RBM15::MRTFA (MKL1) mimicking vascular neoplasm

Extramedullary involvement of acute myeloid leukemia (AML), aka myeloid sarcoma, is a rare phenomenon in acute megakaryoblastic leukemia with RBM15:: MRTFA(MKL1) fusion, which might mimic non-hematologic malignancies. A 7-month-old infant presented with leukocytosis, hepatosplenomegaly, multiple lymphadenopathies, and a solid mass in the right thigh. Initially, the patient was diagnosed with a malignant vascular tumor regarding the expression of vascular markers from the biopsy of the right thigh lesion that was performed after the inconclusive bone marrow biopsy. The second bone marrow biopsy, which was performed due to the partial response to sarcoma treatment, showed hypercellular bone marrow with CD34 and CD61-positive spindle cell infiltration and > 20% basophilic blasts with cytoplasmic blebs. RNA sequencing of soft tissue biopsy revealed the presence of RBM15::MRTFA(MKL1) fusion. Based on these findings, myeloid sarcoma/AML with RBM15::MRTFA(MKL1) fusion diagnosis was made. AML with RBM15::MRTFA(MKL1) fusion can initially present as extramedullary lesions and might cause misdiagnosis of non-hematologic malignancies.

Thalassemia-free and graft-versus-host-free survival: outcomes of hematopoietic stem cell transplantation for thalassemia major, Turkish experience

We report the national data on the outcomes of hematopoietic stem cell transplantation (HSCT) for thalassemia major (TM) patients in Turkey on behalf of the Turkish Pediatric Stem Cell Transplantation Group. We retrospectively enrolled 1469 patients with TM who underwent their first HSCT between 1988 and 2020 in 25 pediatric centers in Turkey. The median follow-up duration and transplant ages were 62 months and 7 years, respectively; 113 patients had chronic graft versus host disease (cGVHD) and the cGVHD rate was 8.3% in surviving patients. Upon the last visit, 30 patients still had cGvHD (2.2%). The 5-year overall survival (OS), thalassemia-free survival (TFS) and thalassemia-GVHD-free survival (TGFS) rates were 92.3%, 82.1%, and 80.8%, respectively. cGVHD incidence was significantly lower in the mixed chimerism (MC) group compared to the complete chimerism (CC) group (p < 0.001). In survival analysis, OS, TFS, and TGFS rates were significantly higher for transplants after 2010. TFS and TGFS rates were better for patients under 7 years and at centers that had performed over 100 thalassemia transplants. Transplants from matched unrelated donors had significantly higher TFS rates. We recommend HSCT before 7 years old in thalassemia patients who have a matched donor for improved outcomes.

Timing of Initiation of Calcineurin Inhibitors in Pediatric Haploidentical Transplantation with Post-Transplantation Cyclophosphamide: Effects on Survival, Relapse, and Cytokine Release Syndrome

BACKGROUND

The use of unmanipulated haploidentical stem cell transplantations (haplo-HSCT) with post-transplant cyclophosphamide (PTCY) in children has emerged as an acceptable alternative to the patients without a matched donor. However, the timing of calcineurin inhibitors (CNI) used in combination with PTCY is increasingly becoming a topic of controversy.

METHOD

We evaluated 49 children with acute leukemia who underwent unmanipulated haplo-HSCT with PTCY according to the initiation day of CNIs (pre- or post-CY).

RESULTS

There were no significant differences in the overall survival analysis between the two groups. The cumulative incidence of relapse at 2 years was 21.2% in the pre-CY group and 38.9% in the post-CY group (p=0.33). Cytokine release syndrome (CRS) was observed more frequently in the post-CY group (p=0.04). The OS and EFS at 2 years in patients with and without CRS in the pre-Cy group were 42.9% vs 87.5% (p=0.04) and 38.1% vs 87.5% (p=0.04), respectively.

CONCLUSION

Our study shows that the argument for starting CNI administration after CY is tenuous, and the rationale for not starting CNI before CY needs to be reconsidered.

Comparison of Total Body Irradiation-based Versus Chemotherapy-based Conditionings for Early Complications of Allogeneic Hematopoietic Stem Cell Transplantation in Children With ALL

BACKGROUND

Total body irradiation (TBI) is the cornerstone of conditioning regimens in pediatric hematopoietic stem cell transplantation for acute lymphoblastic leukemia. As the late effects and survival comparison between TBI and chemotherapy were well analyzed before, in this study, we aim to focus on the first 100 days and early complications of transplantation.

METHODS

This retrospective study involves 72 pediatric patients (0 to 18 y) underwent first hematopoietic stem cell transplantation for acute lymphoblastic leukemia between October 2015 and May 2019. Patients are divided into 2 groups regarding conditioning regimens. Conditionings includes either TBI 1200 cGy/6 fractions/3 days and etoposide phosphate or busulfan, fludarabine, and thiotepa. Busulfan was administered IV and according to body weight.

RESULTS

The incidences of acute graft versus host disease grade 2 to 4, veno-occlusive disease, capillary leakage syndrome, thrombotic microangiopathy, blood stream infection, hemorrhagic cystitis and posterior reversible encephalopathy syndrome before day 100 were similar for both conditioning regimens; however, patients received TBI-based conditioning had significantly longer neutrophil engraftment time (17.5 vs. 13 d, P=0.001) and tended to have more engraftment syndrome (ES) (45.5% for TBI vs. 24.0% for chemotherapy, P=0.069). Multivariate analysis showed that TBI-based conditioning was associated with a longer neutrophil engraftment time (hazard ratio [HR]=1.20, P=0.006), more cytomegalovirus (CMV) reactivation (HR=3.65, P=0.038) and more ES (HR=3.18, P=0.078).

CONCLUSIONS

Our findings support chemotherapy-based regimens with early neutrophil engraftment, less ES and CMV reactivation compared with TBI. Although there is no impact on survival rates, increased incidence of ES and CMV reactivation should be considered in TBI-based regimens.

Prognostic factors for survival in children who relapsed after allogeneic hematopoietic stem cell transplantation for acute leukemia

BACKGROUND

Post-transplant relapse has a dismal prognosis in children with acute leukemia undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). Data on risk factors, treatment options, and outcomes are limited.

PROCEDURE

In this retrospective multicenter study in which a questionnaire was sent to all pediatric transplant centers reporting relapse after allo-HSCT for a cohort of 938 children with acute leukemia, we analyzed 255 children with relapse of acute leukemia after their first allo-HSCT.

RESULTS

The median interval from transplantation to relapse was 180 days, and the median follow-up from relapse to the last follow-up was 1844 days. The 3-year overall survival (OS) rate was 12.0%. The main cause of death was disease progression or subsequent relapse (82.6%). The majority of children received salvage treatment with curative intent without a second HSCT (67.8%), 22.0% of children underwent a second allo-HSCT, and 10.2% received palliative therapy. Isolated extramedullary relapse (hazard ratio (HR): 0.607, P = .011) and relapse earlier than 365 days post-transplantation (HR: 2.101, P < .001 for 0-180 days; HR: 1.522, P = .041 for 181-365 days) were found in multivariate analysis to be significant prognostic factors for outcome. The type of salvage therapy in chemosensitive relapse was identified as a significant prognostic factor for OS.

CONCLUSION

A salvage approach with curative intent may be considered for patients with post-transplant relapse, even if they relapse in the first year post-transplantation. For sustainable remission, a second allo-HSCT may be recommended for patients who achieve complete remission after reinduction treatment.

Allogeneic hematopoietic stem cell transplantation in patients with childhood cerebral adrenoleukodystrophy: A single-center experience "Better prognosis in earlier stage"

BACKGROUND

ALD is a rare X-linked peroxisomal metabolic disorder with many distinct phenotypes of disease that emerge on a wide scale from adrenal insufficiency to fatal cALD which progresses to a vegetative state within a few years. Currently, HSCT is the only treatment method known to stabilize disease progression in patients with cALD. In this study, we aim to report our HSCT experience in patients with cALD and the factors that determine the success of HSCT, as a single-center experience.

METHODS

The study cohort involves 23 boys with cALD and three patients with ALD trait and new-onset abnormal behavior who underwent allogeneic HSCT between January 2012 and September 2019 in our transplantation center. Loes scoring, NFS, scale and MFD were performed for evaluating the severity of the cerebral disease. The study cohort was divided into two groups according to baseline NFS and Loes score: early-stage (NFS ≤ 1 and Loes score <9) and advanced stage (NFS > 1 or Loes score ≥9).

RESULTS

The pretransplant stage of disease impacted both OS and MFD-free survival. The estimated OS and MFD-free survival at 3 years in patients with advanced disease were 46.1% (95% CI 19.0-73.2) and 23.1% (95% CI 0.2-46.0), respectively, and all patients with the early disease were alive (p: .004) and MFD-free (p < .001) at 3 years.

CONCLUSION

This study demonstrated that early HSCT is vital in patients with cALD. The early-stage disease had a significant survival advantage and free from disease progression after HSCT.

Incidence of BKV in the urine and blood samples of pediatric patients undergoing HSCT

The aims were to investigate the incidence of BKV infection and the presence of HC in pediatric patients undergoing HSCT. Twenty-four children patients (M/F: 17/7) undergoing HSCT in a single center over a period of 1 year were included in the study. The presence of BKV DNA was determined by quantitative real-time PCR in plasma and urine samples at the following times: before transplantation, twice a week until engraftment time, and weekly for + 100 days. The mean age of the patients was 7.79 ± 5.03 years, the mean follow-up time was 95.6 ± 25.9 days, and the average number of samples per patient was 15.8 ± 3.2. BKV DNA was detected in at least one urine sample in 91.6% (n: 22) and at least one plasma sample in 75% (n:18) of the patients. The median time to the first BKV DNA positivity in urine and plasma samples was 11 (range: 1-80) and 32 days (range: 2-79), respectively. The median value of BKV DNA copies in urine and plasma were 1.7 × 10⁶ (range: 2.8 × 10¹ -1.2 × 10¹⁴ ) and 1.9 × 10³ copies/mL (range: 3-2.1 × 10⁶ ), respectively. Thirteen patients (54.2%) had hematuria with BKV viruria; 8 (33.3%) patients had viremia. The median value of the BKV DNA copies in urine and plasma was 4.4 × 10⁷ (range: 65-1 × 10¹¹ ) and 2.9 × 10³ (range: 7-7.8 × 10⁴ ) copies/mL in these patients. Two (15.4%) of the 13 patients with BKV viruria and hematuria were diagnosed with BKV-related HC. BKV DNA viral load monitoring of urine and plasma in pediatric HSCT patients with a high risk for viral infections is valuable for understanding the development of BKV-related HC.

Hematopoietic stem cell transplantation in CD40 ligand deficiency: A single-center experience

Deficiency of the CD40L, expressed on the surface of T lymphocytes, is caused by mutations in the glycoprotein CD40L (CD154) gene. Resulting defective humoral and cellular responses cause a clinical presentation that includes recurrent sinopulmonary bacterial infections, opportunistic infections, sclerosing cholangitis, neutropenia, and autoimmune manifestations. HSCT represents the only curative treatment modality. However, the therapeutic decision to use HSCT proves challenging in many cases, mainly due to the lack of a phenotype-genotype correlation. We retrospectively reviewed patients with CD40L deficiency who were transplanted in Antalya and Göztepe MedicalPark Pediatric HSCT units from 2014 to 2019 and followed by Akdeniz University School of Medicine Department of Pediatric Immunology. The records of eight male cases, including one set of twins, were evaluated retrospectively. As two transplants each were performed on the twins, a total of ten transplants were evaluated. Conditioning regimens were predominantly based on myeloablative protocols, except for the twins, who received a non-myeloablative regimen for their first transplantation. Median neutrophil and platelet engraftment days were 13 (range 10-19) and 14 (range 10-42) days, respectively. In seven of ten transplants, a CMV reactivation was developed without morbidity. None of the patients developed GVHD, except for one mild case of acute GVHD. All patients survived, and the median follow-up was 852 days. Our data show that HSCT for patients with CD40 ligand deficiency is a potentially effective treatment for long-term disease control.

Ruxolitinib salvage therapy is effective for steroid-refractory graft-versus-host disease in children: A single-center experience

BACKGROUND

Despite the increasing performance of allogeneic hematopoietic cell transplantation over the last decades, graft-versus-host disease (GVHD) remains the main cause of morbidity and mortality. The efficacy of ruxolitinib against GVHD has been demonstrated in adult studies; however, very few studies have been conducted in children.

PROCEDURE

This study aimed to evaluate the efficacy of ruxolitinib in 29 children with steroid-refractory acute or chronic GVHD. Twenty-five (87%) patients received at least three different immune modulator agents, including methylprednisolone, before initiating ruxolitinib.

RESULTS

All grade 2 acute GVHD patients completely responded to ruxolitinib treatment; 82% of high-grade (3-4) acute GVHD patients and 80% of chronic GVHD (moderate-severe) patients had at least a partial response. Of seven patients with bronchiolitis obliterans, five had a partial response after ruxolitinib. Of 29 patients, 22 were administered steroids at any time in the first month of acute GVHD or the first three months of chronic GVHD during ruxolitinib usage, which was significantly tapered by the end of the observation period.

CONCLUSION

Steroid-refractory acute and chronic pediatric GVHD patients treated with ruxolitinib had a high overall response rate, with the additional benefit of steroid sparing.

Role of a second transplantation for children with acute leukemia following posttransplantation relapse: a study by the Turkish Bone Marrow Transplantation Study Group

We examined outcomes of 51 pediatric patients with relapsed acute leukemia (AL) who underwent a second allogeneic hematopoietic stem cell transplantation (alloHSCT). After a median follow-up of 941 days (range, 69-2842 days), leukemia-free survival (LFS) and overall survival (OS) at 3 years were 26.6% and 25.6%, respectively. The nonrelapse mortality rate (NMR) and cumulative incidence of relapse (CIR) were 36.4% and 42.4%, respectively. The Cox regression analysis demonstrated that the risk factors at second transplantation for predicting limited LFS were active disease (hazard ratio (HR) = 5.1), reduced intensity conditioning (RIC) (HR = 5.0), matched unrelated donor (MUD) (HR = 3.4) and performance score <80 (HR = 3.2). Pediatric patients with AL who relapsed after their first alloHSCT may survive with a second alloHSCT. Disease status, conditioning intensity, donor type, and performance score at the second transplantation are the relevant risk factors. A score based on these factors may predict the results of the second transplantation.

Haploidentical hematopoietic stem cell transplantation with post-transplant high-dose cyclophosphamide in high-risk children: A single-center study

BACKGROUND

Post-Cy administration for GVHD prophylaxis in unmanipulated haploidentical HSCT has resulted in improved outcomes in recent years. Studies in children are lacking and accordingly we present the outcomes of 62 haploidentical transplantation for high-risk children.

PROCEDURE

We retrospectively assessed 62 transplants in 60 patients who underwent haploidentical-related HSCT with unmanipulated stem cells and for whom Post-Cy was used for GVHD prophylaxis.

RESULTS

Myeloid reconstitution was achieved on day + 30 for 57 of the 62 patients. The median follow-up of the surviving 39 patients (63%) was 26 months, with a range of 6-57 months. The OS and EFS at 2 years were 64.6% (52.0%-77.2%, 95% CI) and 58.9% (46.1%-71.7%, 95% CI), respectively. The only factor in our multivariate analysis that contributed to an inferior EFS was a poor remission status prior to HSCT (HR, 8.30; 1.08-63.56; P = 0.041, 95% CI).

CONCLUSION

The results of T-cell replete haploidentical transplantation with Post-Cy GVHD prophylaxis in high-risk pediatric patients are promising. However, further research is needed to determine the factors that have affect HLA compatibility for predicting the success of haploidentical transplantations.

Risks and outcomes of invasive fungal infections in pediatric allogeneic hematopoietic stem cell transplant recipients receiving fluconazole prophylaxis: a multicenter cohort study by the Turkish Pediatric Bone Marrow Transplantation Study Group

Invasive fungal infections (IFIs) are a major cause of infection-related morbidity and mortality in patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). Data from pediatric settings are scarce. To determine the incidence, risk factors and outcomes of IFIs in a 180-day period post-transplantation, 408 pediatric patients who underwent allogeneic HSCT were retrospectively analyzed. The study included only proven and probable IFIs. The cumulative incidences of IFI were 2.7%, 5.0%, and 6.5% at 30, 100, and 180 days post-transplantation, respectively. According to the multivariate analysis, the factors associated with increased IFI risk in the 180-day period post-HSCT were previous HSCT history (hazard ratio [HR], 4.57; 95% confidence interval [CI] 1.42-14.71; P = .011), use of anti-thymocyte globulin (ATG) (HR, 2.94; 95% CI 1.27-6.80; P = .012), grade III-IV acute graft-versus-host-disease (GVHD) (HR, 2.91; 95% CI 1.24-6.80; P = .014) and late or no lymphocyte engraftment (HR, 2.71; 95% CI 1.30-5.62; P = .007). CMV reactivation was marginally associated with an increased risk of IFI development (HR, 1.91; 95% CI 0.97-3.74; P = .063). IFI-related mortality was 1.5%, and case fatality rate was 27.0%.The close monitoring of IFIs in pediatric patients with severe acute GVHD who receive ATG during conditioning is critical to reduce morbidity and mortality after allogeneic HSCT, particularly among those with prior HSCT and no or late lymphocyte engraftment.

Urgent surgical management of congenital intracranial hemangiopericytoma in a preterm neonate

Hemangiopericytoma is a rare mesenchymal tumor originating from capillary pericytes, known as Zimmermann pericytes. The adult form is not uncommon and generally malignant but tumor is found rarely in children. Here we describe an intracranial hemangiopericytoma in a preterm newborn whose had the tumor resected successfully shortly after birth.

Prognostic Factors and a New Prognostic Index Model for Children and Adolescents with Hodgkin's Lymphoma Who Underwent Autologous Hematopoietic Stem Cell Transplantation: A Multicenter Study of the Turkish Pediatric Bone Marrow Transplantation Study Group

Objective:

The prognostic factors and a new childhood prognostic index after autologous hematopoietic stem cell transplantation (AHSCT) in patients with relapsed/refractory Hodgkin’s lymphoma (HL) were evaluated.

Materials and Methods:

The prognostic factors of 61 patients who underwent AHSCT between January 1990 and December 2014 were evaluated. In addition, the Age-Adjusted International Prognostic Index and the Childhood International Prognostic Index (CIPI) were evaluated for their impact on prognosis.

Results:

The median age of the 61 patients was 14.8 years (minimum-maximum: 5-20 years) at the time of AHSCT. There were single relapses in 28 patients, ≥2 relapses in eight patients, and refractory disease in 25 patients. The chemosensitivity/chemorefractory ratio was 36/25. No pretransplant radiotherapy, no remission at the time of transplantation, posttransplant white blood cell count over 10x10³/µL, posttransplant positron emission tomography positivity at day 100, and serum albumin of <2.5 g/dL at diagnosis were correlated with progression-free survival. No remission at the time of transplantation, bone marrow positivity at diagnosis, and relapse after AHSCT were significant parameters for overall survival.

Conclusion:

The major factors affecting the progression-free and overall survival were clearly demonstrated. A CIPI that uses a lactate dehydrogenase level of 500 IU/L worked well for estimating the prognosis. We recommend AHSCT at first complete remission for relapsed cases, and it should also be taken into consideration for patients with high prognostic scores at diagnosis.

Outcomes of high-grade gastrointestinal graft-versus-host disease posthematopoietic stem cell transplantation in children

We explored the clinical course of acute high-grade gastrointestinal graft-versus-host disease in children in a single center. This was a retrospective analysis of 28 pediatric patients who presented with a clinical diagnosis of stage III and IV acute graft-versus-host disease (aGVHD) of the gastrointestinal system (GIS). Generally, skin involvement was the initial manifestation of aGVHD that began in the first 3 weeks of hematopoietic stem cell transplantation (HSCT); on the other hand, GIS involvement predominated after the second week of HSCT. Reported adult data show a survival rate of only 25%; however, our study showed more favorable outcomes in children with a survival rate of 55%. We monitored levels of albumin and immunoglobulin G and observed low levels overall during treatment of unresponsive patients, although only albumin levels were shown to be significantly different. We observed a significant increase in mortality with the use of antithymocyte globulin in GIS aGVHD, although antithymocyte globulin used for graft-versus-host disease prophylaxis had no demonstrable effect on GIS aGVHD mortality. Whether the significantly lower GIS aGVHD mortality among the children recruited in our study than among their historical adult counterparts is a primary result of the specific attributes of the pediatric GIS, or whether it originated from HSCT kinetics remains to be determined by future studies.

Outcome of autologous hematopoietic stem cell transplantation in children and adolescents with relapsed or refractory Hodgkin's lymphoma

This study evaluates the outcome of 66 pediatric patients with rrHL who underwent autoHSCT. Twenty-nine patients experienced early relapse, and 19 patients experienced late relapse. Of 18 newly diagnosed with HL, 13 were primary refractory disease and five had late responsive disease. At the time of transplantation, only 68% of the patients were chemosensitive. The majority of patients received BCNU + etoposide + ara-C + melphalan for conditioning (45/66), and peripheral blood (56/66) was used as a source of stem cells. After a median follow-up period of 39 months, 46 patients were alive. At five yr, the probabilities of OS, EFS, the relapse rate, and the non-relapse mortality rate were 63.1%, 54.3%, 36.4%, and 9.1%, respectively. The probability of EFS in chemosensitive and chemoresistant patients at five yr was 72.3% and 19%, respectively (p < 0.001). Multivariate analysis showed that chemoresistant disease at the time of transplantation was the only factor predicting limited both OS (hazard ratio = 4.073) and EFS (hazard ratio = 4.599). AutoHSCT plays an important role for the treatment of rrHL in children and adolescents, and survival rates are better for patients with chemosensitive disease at the time of transplantation.

UNUSUAL CLINICAL CASES THAT MIMIC ACUTE DISSEMINATED ENCEPHALOMYELITIS

Acute disseminated encephalomyelitis (ADEM) is an immune-mediated monophasic inflammatory demyelinating disorder of the central nervous system which poses a diagnostic challenge. We report on six cases of different etiologies that mimicked the clinical and radiologic findings of ADEM. The cases were collected from four different reference hospitals in Turkey. The same radiologist from the Akdeniz University Faculty of Medicine examined the magnetic resonance images of all patients. Three (50%) patients had antecedent infections. Initial symptoms of the patients were as follows: fever in 50%, altered consciousness in 33.3% and convulsions in 16.7% of patients. Neurologic examination showed long tract signs in 83.3%, ataxia in 50% and altered consciousness in 50% of patients. Cerebrospinal fluid examination revealed lymphocytic pleocytosis only in case 6. Four patients received steroid pulse therapy and one of these initially underwent intravenous immunoglobulin therapy. The patients' definitive diagnoses were as follows: paraspinal neuroblastoma-associated paraneoplastic syndrome; histiocytic sarcoma; mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes; and cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy in one patient each, while two patients had hemophagocytic syndrome. The present case series demonstrated difficulties in diagnosing ADEM while revealing extremely rare disorders that mimic ADEM radiologically and clinically.

Idiopathic hyperammonemia after hematopoietic stem cell transplantation: A case report

IHA is characterized by a sudden increase in plasma ammonia levels in the absence of any identifiable causes, which mostly results in intractable coma and high mortality. It has been reported in some patients after receiving intensive chemotherapy for hematological malignancy or HSCT. We describe a case of a patient with FA that developed acute idiopathic hyperammonemia after the preparative regimen for HSCT.

Analysis of human herpes virus 6 infections with a quantitative, standardized, commercial kit in pediatric stem cell transplant recipients after transplantation

BACKGROUND AND OBJECTIVES

The aim of the study was to assess the incidence and clinical relevance of active Human Herpes Virus 6 (HHV6) infections in pediatric patients after allogeneic stem cell transplantation.

DESIGN AND SETTINGS

Retrospective analysis of samples prospectively collected at Akdeniz University Medical Faculty Hospital, Antalya, Turkey, between May 2006 and July 2007 from 15 pediatric patients with allogeneic hematopoietic stem cell transplantation (HSCT).

SUBJECTS AND METHODS

A commercial quantitative real-time polymerase chain reaction kit was used to analyze plasma samples collected from 15 pediatric allogeneic HSCT recipients.

RESULTS

HHV6 DNA was found positive in 8 (53%) patients. HHV6 DNA levels above 1000 copies/mL were found only in 2 patients and they were also consecutively positive for HHV6 DNA. Age at transplantation, use of ATG, and receiving grafts other than HLA identical siblings increased the risk, with a statistically significant difference, of having HHV6 reactivation with levels exceeding 1000 copies/mL (P values, respectively, P=.03, .001, .025). Active HHV6 infections with HHV6 viremia levels higher than 1000 copies/mL were associated with subsequent delayed platelet engraftment (P=.001), acute graft versus host disease (P=.001), skin rash, and fever of unknown origin.

CONCLUSION

More than half of pediatric allogeneic HSCT patients develop active HHV6 infection, and especially in patients with high viremic loads, the infection can result in serious clinical situations. A clinically significant cutoff value for viremia seems to be necessary to predict serious clinical complications.

HLA-matched family hematopoetic stem cell transplantation in children with beta thalassemia major: the experience of the Turkish Pediatric Bone Marrow Transplantation Group

From January 1991 to June 2009, 245 children with beta thalassemia major who underwent their first allogeneic HSCT in Turkey and who were followed for a minimum of one yr post-transplantation were enrolled this study. The median age of the patients was 6.6 yr old (range, 1-22 yr). The distribution of Pesaro risk class I, II, and III categories was 41, 130, and 63 children, respectively. The median serum ferritin level was 2203 ng/mL. Eighty-eight patients received bone marrow (BM) stem cells; 137, peripheral blood (PB) stem cells; and 20, cord blood (CB) stem cells. The donors were HLA-matched siblings or parents. Median engraftment times were shorter in PBSCT patients compared with the BMT group (p < 0.001). Grade II-IV acute GvHD was observed in 33 children (13.5%), while cGvHD was observed in 28 patients (12.5%), eight of whom had the extensive form. Thalassemic reconstitution was observed in 43 (17%) of the transplant patients. Post-transplant aplasia occurred in three patients, and the TRM rate was 7.75%. Seventeen patients were lost after 100 days. The thalassemia-free survival and OS rates were 68% (95% CI, 61.8-74.2) and 85.0% (95% CI, 80.2-89.8), respectively. We believe that this study is important because it is the first multicenter national data for children with beta thalassemia major receiving HSCT.

Successful unrelated bone marrow transplantation in two siblings with alpha-mannosidosis

Alpha-mannosidosis is a rare lysosomal storage disorder with an autosomal recessive inheritance. Deficient alpha-mannosidase activity leads to lysosomal accumulation of mannose-rich oligosaccharides. The disease characterized by mental retardation, skeletal changes, hearing impairment, and recurrent infections. Stem cell transplantation has been shown to be an effective treatment. It works by providing increased levels of α-mannosidase in the localized extracellular milieu to provide improvements in skeletal malformations, neurocognitive, and sensorineural function. In this case report, we describe a pair of siblings with α-mannosidosis who successfully underwent HSCT from matched unrelated donors. In both siblings, enzyme levels reached to normal limits and improvements in clinical symptoms were recognized early after HSCT. We conclude that HSCT should be considered as a therapeutic approach in patients with alpha-mannosidosis before disease-related complications have developed.

Quality of life assessment in hematopoietic stem cell transplantation performed on thalassemia major patients

Although successful hematopoietic stem cell transplantation (HSCT) can offer a cure in thalassemia major, there are only a few and noncomprehensive studies of its effect on the quality of life (QoL), as it is expected to increase the QoL by ending transfusion-related issues. Our objective was to compare the health-related quality of life (HRQoL) of transplanted and nontransplanted thalassemia major patients in a developing country. We have studied the QoL effect of HSCT in consecutively invited 50 nontransplanted and 49 transplanted patients who had received transplants from HLA matched related donors at least two years ago. PedsQL questionnaire was used for the patients under 18 years of age and World Health Organization's WHOQoL-BREF questionnaire for above 18 years of age. Higher QoL was determined in HSCT performed group surveyed in 5-18 years' age group. Detailed analysis marked the profound difference in 8-12 year subgroup, particularly in physical activity questionnaires. QoL scores in HSCT performed adult group are higher than the transfusion-dependent group, especially in physical activity domain. Transplanted adult patients rated their overall health significantly better than patients on conventional therapy. The patients who still have chronic graft versus host disease rated worse compared to those without it. In conclusion, thalassemia major patients who have undergone HSCT at least two years before assessment are not inferior to the transfusion-dependent group with regard to the QoL and have a better QoL than transfusion-dependent patients in some areas. The QoL score is better for school children and adolescents; therefore, we suggest HSCT before primary school. GVHD reduces the QoL significantly and it is obvious that GVHD prevention should be one of the primary goals of post-HSCT follow-up.

Hematopoietic stem cell transplantation activity and trends at a pediatric transplantation center in Turkey during 1998-2008

Objective: The aim of this study was to document hematopoietic stem cell transplantation (HSCT) activity and trends at our treatment center.

Material and Methods: Data collected over a 10-year period were retrospectively analyzed, concentrating primarily on types of HSCT, transplant-related mortality (TRM), stem cell sources, indications for HSCT, and causes of death following HSCT.

Results: In total, 222 allogeneic (allo)-HSCT (87.4%) and 32 autologous (auto)-HSCT (12.6%) procedures were performed between 1998 and 2008. Stem cells obtained from unrelated donors were used in 22.6% (50/222) of the allo- HSCTs. Cord blood was the source of hematopoietic stem cells (HSC) in 12.2% of all transplants. The most common indication for allo-HSCT was hemoglobinopathy (43.2%), versus neuroblastoma (53.1%) for auto-HSCT. The TRM rate 1 year post transplantation was 18.3% ± 2.5% for all transplants, but differed according to transplantation type (23.5% ± 7.9% for auto-HSCT and 17.5% ± 2.6% for allo-HSCT). The most common cause of death 1 year post HSCT was infection (35.9%).

Conclusion: The TRM rate in the patients that underwent allo-HSCT was similar to that which has been previously reported; however, the TRM rate in the patients that underwent auto-HSCT was higher than previously reported in developed countries. The selection of these patients to be transplanted must be made attentively.

Aberrations of chromosomes 9 and 22 in acute lymphoblastic leukemia cases detected by ES-fluorescence in situ hybridization

A reciprocal translocation between chromosomes 9 and 22 creates oncogenic BCR/ABL fusion in the breakpoint region of the derivative chromosome 22. The aim of this study was to evaluate the importance of atypical fluorescence in situ hybridization (FISH) signal patterns in pediatric and adult acute lymphoblastic leukemia (ALL) cases. We evaluated t(9;22) translocation in 208 cases with ALL (294 tests), including 139 childhood and 69 adult cases by FISH technique using BCR/ABL extra signal (ES) probe. FISH signal patterns observed in pediatric ALL cases were as follows; Major-BCR/ABL (M-BCR/ABL) (1.4%), minor-BCR/ABL (m-BCR/ABL) (3.6%), trisomy 9 (4.3%), trisomy 22 (4.3%), trisomy or tetrasomy of both chromosomes 9 and 22 (2.9%), monosomy 9 (1.4%), monosomy 22 (0.7%), ABL gene amplification (1.4%), derivative chromosome 9 deletion (1.4%), and extra copies of the Philadelphia chromosome (1.4%). FISH signal patterns observed in adult ALL cases were as follows; M-BCR/ABL (5.8%), m-BCR/ABL (11.6%), two different cell clones with major and minor BCR/ABL signal pattern (2.9%), extra copies of Philadelphia chromosome (4.3%), derivative chromosome 9 deletion (1.4%), trisomy 9 (2.9%), tetraploidy (1.4%), monosomy 9 (1.4%), trisomy 22 (1.4%), and coexistence of both trisomy 22 and monosomy 9 (1.4%). Trisomy 9, trisomy 22, and polyploidy of chromosomes 9 and 22 were specific atypical FISH signal patterns for childhood B cell acute lymphoblastic leukemia (B-ALL) patients. However, monosomy 9 and ABL gene amplification were highly specific for childhood T cell acute lymphoblastic leukemia (T-ALL) patients. Our report presents the correlation between atypical FISH signal patterns and clinical findings of a large group of ALL cases.

The value of donor lymphocyte infusions in thalassemia patients at imminent risk of graft rejection following stem cell transplantation

BACKGROUND

The aim was to evaluate the feasibility of donor lymphocyte infusion (DLI) in transplanted patients with thalassemia who were at imminent risk of graft rejection (GR).

PROCEDURE

We retrospectively evaluated outcomes in a cohort of 19 patients with thalassemia who received DLI following 21 transplantations. Patients were divided into three groups depending on indication and time of DLI: group I, mixed chimerism-level-3 (MC-level-3) within 2 months and subsequently receiving DLI; group II, MC-level-3 within 2 months and receiving deferred DLI beyond post-transplant 2.5 months; group III, receiving DLI because of a gradual decrease in both donor cells and hemoglobin levels without MC-level-3 within 2 months.

RESULTS

Three patients evolved to compete chimerism (16%), 9 patients had MC with transfusion independency (47%) and 7 had GR (37%). Three of 7 patients in group I, 1 of 4 patients in group II and 8 of 10 patients in group III preserved the graft. Although significant increases in the percentage of donor cells were not detected in group III, hemoglobin levels improved (median, 6.8-8.8 g/dl, P = 0.002).

CONCLUSION

The risk of GR is high in patients with thalassemia who have MC-level-3 within 2 months after transplantation. DLI is a feasible method for converting unstable MC towards stable MC or full donor chimerism, but its efficacy is partially related to the percentage of residual host cells at the time of infusion. Serial chimerism studies can identify unstable MC earlier and may guide the proper timing of intervention.

Neurocognitive function in patients with β-thalassemia major

BACKGROUND

Children with β-thalassemia major (β-TM) have multiple risk factors for developing cognitive impairment. The aim of the present study was to evaluate cognitive function in patients with β-TM.

METHODS

Twenty children with β-TM were enrolled into the study and were compared with a control group consisting of 21 healthy children. All participants were evaluated with neuropsychological tests and event-related potentials (ERP).

RESULTS

All of the participants had normal IQ scores, but the patient group had significantly lower full-scale, performance, and verbal IQs compared with the control group (P < 0.05). The number of children with visuomotor dysfunction was higher in the patient group compared with the control group (P < 0.05). In the P300 test, the patient group had significantly prolonged N1, P2 and N2 latencies at the FZ, and a prolonged N1 latency at the Cz compared with the control group (P < 0.05). The patient group also had lower N1 and P3N4 amplitudes at the Fz, and lower N1, N1P2 and P3N4 amplitudes at the Cz when compared with the control group (P < 0.05). Mismatch negativity latency and duration were longer in the patient group (P < 0.05).

CONCLUSIONS

Neuropsychological tests are safe, and reliable for the diagnosis of cognitive impairment in β-TM patients, and the use of ERP may facilitate early diagnosis. The number of β-TM patients in the present study was limited, however, and larger numbers of patients are required in further studies.

Treatment of Wilms tumor: a report from the Turkish Pediatric Oncology Group (TPOG)

AIM

To standardize diagnosis and treatment of childhood Wilms tumor (WT) in Turkey.

METHODS AND PATIENTS

Between 1998 and 2006, WT patients were registered from 19 centers. Patients <16 years with unilateral WT whose treatment started in first postoperative 3 weeks were included. Treatments were stage I favorable (FH) and unfavorable histology (UH) patients, VCR + Act-D; stage IIA FH, VCR + Act-D; stage IIB FH, VCR + Act-D + radiotherapy (RT); stage III-IV FH, VCR + Act-D + adriamycin (ADR) + RT; stages II-IV UH tumors, VCR + Act-D + ADR + etoposide + RT.

RESULTS

165/254 registered cases were eligible (bilateral, 5.9%) [median age 3.0 years; M/F: 0.99; 50/165 cases < or =2 years]. 9.7% cases had UH tumors. Disease stages were stage I 23.6%; IIA 36.4%; IIB 5.5%; III 22.4%; IV 12.1%. Cases >2 years had significantly more advanced disease. 1/11 cases with recurrent disease died; 2/165 had progressive disease, 2/165 had secondary cancers, and all 4 died. In all cases 4-year OS and EFS were 92.8 and 86.5%, respectively. Both OS and EFS were significantly worse in stage IV.

CONCLUSIONS

Despite problems in patient management and follow-up, treatment results were encouraging in this first national experience with a multicentric study in pediatric oncology. Revisions and modifications are planned to further improve results and minimize short- and long-term side effects.

Piperacillin/tazobactam versus cefepime for the empirical treatment of pediatric cancer patients with neutropenia and fever: a randomized and open-label study

OBJECTIVES

This is a prospective, randomized, and open-label clinical trial that examines the efficiency and safety of PIP/TAZO monotherapy in comparison to cefepime (CEF), for the empirical treatment of pediatric cancer patients with neutropenia and fever.

METHODS

One hundred thirty-one consecutive febrile episodes in 70 neutropenic pediatric cancer patients received randomized treatment either with piperacillin/tazobactam (PIP/TAZO) 80 mg/kg piperacillin/10 mg/kg tazobactam every 6 hr or CEF 50 mg/kg every 8 hr. Clinical response was determined at completion of therapy. Duration of fever, neutropenia, hospitalization, the need for modification of the therapy, and mortality rates were compared between the two groups.

RESULTS

One hundred twenty-seven episodes in 69 patients (35 females, 34 males) with a median age of 4.2 years were assessed for efficiency (65 PIP/TAZO, 62 CEF). The frequency of success without modification of treatment was nearly identical for both PIP/TAZO (60.0%) and CEF (61.3%) (P > 0.05). The overall response rate, with or without modification of assigned treatment, was 96.9% for PIP/TAZO and 98.4% for CEP (P > 0.05). Infection-related mortality at the end of the febrile episode was 2.4%. Duration of fever and hospitalization were not different between the treatment groups. No major side effects were observed in neither of the groups.

CONCLUSIONS

PIP/TAZO treatment was as effective and safe as CEF monotherapy as an initial empirical regimen in pediatric cancer patients with fever and neutropenia.

Unrelated cord blood transplantation in children with severe congenital neutropenia

SCN is an inherited hematological disorder with severe neutropenia and recurrent infections. Although there are some reports that recombinant rhG-CSF improves clinical outcome, allogeneic HSCT appears to be the only curative treatment for these patients. We report here two children with SCN successfully treated by CBT from unrelated donors. They were refractory to rhG-CSF treatment and have no identical family donor. Bu + CY were given as conditioning. Case 1 and Case 2 received 6/6 and 5/6 HLA-matched unrelated umbilical cord blood, respectively. The number of infused nucleated cells was 6, 18 x 10(7)/kg and CD34(+) cell number was 3, 74 x 10(5)/kg in Case 1. Those cell numbers were 8, 8 x 10(7)/kg and 5, 34 x 10(5)/kg for Case 2, respectively. Neutrophil/platelet engraftments were 45/49 days in Case 1 and 24/36 days in Case 2. Grade II cutaneous acute GVHD was seen in Case 2 that was treated successfully with prednisolone. Both patients are well with normal hematological findings and full donor chimerism for post-transplant 20 and 24 months, respectively. We conclude that UCB can be considered as a safe source of stem cell in patients with SCN who need urgent HSCT.

Renal function after hematopoietic stem cell transplantation in children

OBJECTIVES

The aim of this study was to assess glomerular and tubular renal function after HSCT in children in a prospective trial.

METHODS

Renal function was assessed prospectively before HSCT (on day -10), on days +30, +100, and at least 6 months after transplantation in 34 patients (21 females/13 males) with a mean age of 8.2 years. The following parameters were investigated: glomerular filtration rate (GFR) by creatinine clearance (CrCl), cystatin C (CysC)-based formula and plasma clearance of radiolabeled diethylenetriaminepentaacetic acid ((99m)Tc-DTPA), urinary excretion of beta(2)-microglobulin (beta(2)M), beta-N-acetylglucosaminidase (beta-NAG), fractional excretion of sodium (FE(Na)) and fractional tubular phosphate reabsorption (TP/CrCl).

RESULTS

Nine patients (26.4%) suffered from acute renal insufficiency within the first 100 days after transplantation. All patients who developed acute renal insufficiency were treated successfully without renal replacement therapy. Age, sex, primary diagnosis, sepsis, veno-occlusive disease, acute graft versus host disease, and use of vancomycin were not significant risk factors for the development of acute renal insufficiency. The medians (99m)Tc-DTPA-based GFR of patients after HSCT showed a statistically significant decrease when compared with pre-transplant values. beta-NAG excretion was significantly elevated in the first 30 days after HSCT.

CONCLUSION

Acute and chronic renal impairment can be developed in patients who undergo HSCT even though the pre-transplant renal function is in normal limits and the conditioning regimen does not include TBI. Both glomerular and tubular renal function evaluation should be part of a long-term follow-up in children following HSCT.

Better posttransplant outcome with fludarabine based conditioning in multitransfused fanconi anemia patients who underwent peripheral blood stem cell transplantation

Several investigators have been looking for less toxic conditioning regimen for stem cell transplantation in Fanconi anemia (FA) patients because of sensitivity to DNA cross-linking agents and tendency to malignancy. We report 16 multitransfused FA patients who underwent peripheral stem cell transplantation from 13 related and 3 unrelated donors. Although the first 6 patients received thoraco-abdominal irradiation + cyclophosphamide + antithymocyte globulin (regimen A) for conditioning, fludarabine (FLU) + cyclophosphamide + antithymocyte globulin (regimen B) were used in the last 10 patients in which 3 of them received unrelated graft. Cyclosporin A was given alone for the related allografts but also included mycophenolate mofetil for the unrelated allograft as graft versus host disease prophylaxis. We observed a lower risk of peritransplant morbidity and mortality with fewer and milder graft versus host disease in FLU based group. We lost 3 patients in regimen A group and 1 of them from secondary acute myeloid leukemia. Three patients are alive with transfusion independent. In regimen B group, 9 of 10 patients are alive with normal hematologic parameters and full donor chimerism. The longest follow-up durations are 90 and 60 months in regimen A and B, respectively. In conclusion, FLU based conditioning is more effective and successful with lower toxicity in multitransfused FA patients. However, it needs more experience and longer follow up duration.

Disseminated fusariosis caused by Fusarium verticillioides in an acute lymphoblastic leukemia patient after allogeneic hematopoietic stem cell transplantation

Fusarium species are saprophytic molds which cause disseminated or localized infections in humans. Disseminated Fusarium infection can cause significant morbidity and mortality in immunocompromised patients. We present a case of disseminated fusariosis caused by Fusarium verticillioides in a patient with acute lymphoblastic leukemia and successfully treated using both liposomal amphotericin B and voriconazole.

Burkitt's lymphoma following a pediatric liver transplantation: predictive negative value of serologic response to Epstein-Barr virus

Post-transplant lymphoproliferative disorder (PTLD) represents a spectrum of Epstein-Barr virus (EBV)-related clinical diseases, from a benign mononucleosis-like illness to a fulminant non-Hodgkin's lymphoma. Because a large proportion of children are seronegative at the time of transplantation, recipients are at high risk of contracting primary EBV infection and subsequently developing PTLD. Surveillance techniques with antibody titers and/or polymerase chain reaction (PCR) may have a role in some high-risk settings. A 12-year-old boy whose serologic response to EBV was negative during follow-up after liver transplantation (LTx) developed Burkitt's lymphoma, a rare and the most severe variant of EBV-related PTLD, 32 months after LTx. He expired possibly due to side effects of treatment. We recommend that viral monitoring must be done using PCR during follow-up of pediatric LTx to prevent dramatic outcomes.

Donor cell-derived acute myeloblastic leukemia after allogeneic peripheral blood hematopoietic stem cell transplantation for juvenile myelomonocytic leukemia

Despite its rarity, donor cell leukemia (DCL) is a most intriguing entity. We report here the case of a 5 year-old girl with juvenile myelomonocytic leukemia and normal female karyotype who developed acute myeloblastic leukemia with a karyotype of 46, X, t(X; 7) (p21; p11.2), der(7) t(3; 7) (q13.3; q22) 5 months after peripheral blood hematopoietic stem cell transplantation from her HLA-matched sister. We performed the analysis of short tandem repeat sequence markers to DNA obtained from donor peripheral blood, patient's peripheral blood including leukemic blasts and patient's hair root. This analysis showed that the leukemic blood DNA matched the donor blood DNA and not the patient's DNA, thus confirming DCL. To our knowledge, this is the first case of DCL after peripheral blood SCT for juvenile myelomonocytic leukemia.

Cytomegalovirus antigenemia and outcomes of patients undergoing allogeneic peripheral blood stem cell transplantation: effects of long-term high-dose acyclovir prophylaxis and preemptive ganciclovir treatment

Cytomegalovirus (CMV) disease is a frequent cause of morbidity and mortality following allogeneic hematopoietic stem cell transplantation. In order to investigate the relationships between antigenemia, high-dose acyclovir (HDACV) prophylaxis, preemptive ganciclovir (GCV) therapy, and outcomes, we analyzed the records of 105 patients, including both pediatric and adult populations, who underwent allogeneic peripheral blood stem cell transplantation (PBSCT) and who were at risk for CMV reactivation and disease (both recipient and donor seropositive). All received HDACV until neutrophil engraftment, but prophylaxis was continued till post-transplant day 180 only in pediatric patients in conjunction with weekly CMV pp65 antigenemia monitoring. Antigenemia-guided preemptive strategy with GCV was used for all patients. CMV antigenemia developed in 45 patients (42.9%) and CMV disease in 13 (12.4%). The frequencies for antigenemia were 31.3 and 63.2% in pediatric and adult groups (P = 0.002). All CMV diseases were in the adult group (P<0.001). Age at transplantation, underlying disease, long-term HDACV prophylaxis and acute graft versus host disease (aGVHD) were all found to be a significant risk factors for antigenemia. All of these factors other than aGVHD and conditioning regimen were also the significant risk factors for CMV disease. However, when we analyzed the pediatric and adult patients separately, dropping "long-term HDACV prophylaxis," none of these parameters were significant risk factors for CMV disease. In conclusion, we hypothesize that long-term HDACV prophylaxis in the GCV era results in a low incidence of CMV reactivation and disease in patients undergoing PBSCT.

Episodes of fever and neutropenia in children with cancer in a tertiary care medical center in Turkey

The aim of this study was to determine the clinical features and microbiological spectrum during episodes of fever and neutropenia (FEN) in children with cancer. Demographics, clinical information, treatment approaches, and outcomes of the patients admitted to Akdeniz University Department of Pediatric Hematology and Oncology from October 1996 to June 2004 were evaluated retrospectively. Of the total 621 episodes, 345 (55.5%) were microbiologically documented (MDI) (36.4%) or clinically suspected (CSI) (19.2%) infections. A total of 425 infections were diagnosed in 345 episodes, in which lower respiratory tract infections were the most common (32.7%). Among the microbiologically documented infections, Staphylococci (both coagulase-negative and coagulase-positive) (38.7%) and Escherichia coli (12.9%) were the most frequently isolated gram-positive and gram-negative organisms, respectively. Monocytopenia less than 100/microL (p = 0.01), duration of neutropenia (p = .01) and fever (p < .001) were significantly associated with documented infection by univariate analysis. In addition, presence of previous FEN episode (p = .001) and hypotension (p = .029) were also found to be risk factors. However, using the multivariate analyses, only the duration of fever was found to be an independent risk factor for MDI. The rate of mortality was significantly higher among under 1-year-old patients (p = .039). Hypotension and uncontrolled cancer were the significant determinants of poor prognosis. These results may help to consider a more selective management strategy for children with these problems.

Posttransplant Lymphoproliferative Disorders in Transplant Recipients

Posttransplant lymphoproliferative disorder (PTLD) is a serious complication of organ transplantation, with a reported incidence between 0.8% and 32%. The incidence of PTLD mainly depends on the transplanted organ, the immunosuppressive drugs, the viral serology, and the age of the recipient. The aim of our study was to analyze our patients diagnosed with PTLD. Among 1040 transplantations, including 931 renal, 14 heart, 55 liver and 40 allogeneic peripheral blood stem cell (PBSC), 8 patients (7 male, 1 female) were diagnosed with PTLD. Five patients had undergone renal, one cardiac, one liver, and one PBSC transplantations. Four patients were diagnosed within the first year of transplantation. Six patients presented with abdominal disease, one with convulsions, and one with peripheral lymph node involvement. According to the World Health Organization classification system, six patients were diagnosed as diffuse large B-cell lymphoma, one patient Burkitt's lymphoma, and one polymorphic PTLD. At the time of diagnosis, 7 patients showed positive Epstein-Barr virus (EBV) and cytomegalovirus (CMV) Ig G and negative Ig M; one patient, positive EBV Ig M and negative CMV Ig G and M. EBV viral load was extremely high in the plasma of two patients by polymerase chain reaction. One of these patient's pathologic tissue revealed positive EBV DNA, which was not detected in six of the other eight patients. This patient was an 8-year-old boy diagnosed with Burkitt's lymphoma at 31 months after liver transplantation. Seven patients died of disease or complications of chemotherapy. Only one patient survived after the diagnosis of PTLD. In conclusion, even with treatment the mortality rate was high among our patients with PTLD. To decrease the incidence of PTLD and related mortality, risk factors must be evaluated in multicenter studies.