Minimal residual disease-based risk stratification in Chinese childhood acute lymphoblastic leukemia by flow cytometry and plasma DNA quantitative polymerase chain reaction.

Minimal residual disease, or MRD, is an important prognostic indicator in childhood acute lymphoblastic leukemia. In ALL-IC-BFM 2002 study, we employed a standardized method of flow cytometry MRD monitoring for multiple centers internationally using uniformed gating, and determined the relevant MRD-based risk stratification strategies in our local patient cohort. We also evaluated a novel method of PCR MRD quantitation using peripheral blood plasma. For the bone marrow flow MRD study, patients could be stratified into 3 risk groups according to MRD level using a single time-point at day-15 (Model I) (I-A: <0.1%, I-B: 0.1-10%, I-C: >10%), or using two time-points at day-15 and day-33 (Model II) (II-A: day-15<10% and day-33<0.01%, II-B: day-15 ≥ 10% or day-33 ≥ 0.01% but not both, II-C: day-15 ≥ 10% and day-33 ≥ 0.01%), which showed significantly superior prediction of relapse (p = .00047 and <0.0001 respectively). Importantly, patients with good outcome (frequency: 56.0%, event-free survival: 90.1%) could be more accurately predicted by Model II. In peripheral blood plasma PCR MRD investigation, patients with day-15-MRD ≥ 10(-4) were at a significantly higher risk of relapse (p = 0.0117). By multivariate analysis, MRD results from both methods could independently predict patients' prognosis, with 20-35-fold increase in risk of relapse for flow MRD I-C and II-C respectively, and 5.8-fold for patients having plasma MRD of ≥ 10(-4). We confirmed that MRD detection by flow cytometry is useful for prognostic evaluation in our Chinese cohort of childhood ALL after treatment. Moreover, peripheral blood plasma DNA MRD can be an alternative where bone marrow specimen is unavailable and as a less invasive method, which allows close monitoring.

Intracranial haemorrhage among Chinese children with immune thrombocytopenia in a Hong Kong regional hospital.

OBJECTIVE: To evaluate potential risk factors, presenting symptoms, management, and outcomes of intracranial haemorrhage in Chinese children with immune thrombocytopenia managed in a regional hospital. DESIGN: Retrospective case series. SETTING: A regional hospital in Hong Kong. PATIENTS: All paediatric patients with immune thrombocytopenia complicated by intracranial haemorrhage in the period January 1996 to December 2009. RESULTS: Nine episodes of intracranial haemorrhage were reported in eight patients (aged 0.9 to 19 years) with immune thrombocytopenia; three of the patients had acute immune thrombocytopenia and the other five had chronic immune thrombocytopenia. Intracranial haemorrhage occurred as early as the initial presentation with immune thrombocytopenia (n=2) and as late as up to 5 years after the diagnosis. The median platelet count at the time of intracranial haemorrhage was 12 x 10(9) /L (<10 x 10(9) /L [n=4]; 10-20 x 10(9) /L [n=2]; >20 x 10(9) /L [n=3]). The bleeding was considered spontaneous in six episodes, while head trauma (n=2) and vascular malformation (n=1) were identified in three patients with mild-to-moderate thrombocytopenia (42-82 x 10(9) /L) at the time of the bleed. Headache and mucosal bleeding were the commonest presenting symptoms (n=5). All patients received multimodal treatment after diagnosis of intracranial haemorrhage, and included platelet transfusion (n=8), intravenous immunoglobulin (n=6), methylprednisolone (n=4), and splenectomy (n=4); three individuals underwent neurosurgical interventions. One (11%) patient died of posterior fossa bleeding and one (11%) had neurological sequelae. All survivors achieved remission of their immune thrombocytopenia with a median follow-up of 5.3 years. CONCLUSION: Intracranial haemorrhage can occur anytime during the course of immune thrombocytopenia. A high index of suspicion for intracranial haemorrhage should be maintained during follow-up, as favourable outcomes can be achieved after early and vigorous interventions.

Transfusion-dependent anaemia of undetermined origin: a distinctive syndrome in paediatric medical tourism.

INTRODUCTION: The underlying diagnosis of severe anaemic illnesses in children may not be easy to identify at times, especially when regular blood transfusion has been started. MATERIALS AND METHODS: International children patients attending a haematology clinic for diagnostic evaluation were identified retrospectively if they had to receive repeated blood transfusions with an undiagnosed illness or an incorrect diagnosis. Their demographic data, presenting features, and eventual diagnosis were described. RESULTS: Twelve children including 7 boys were enrolled from March 2007 to August 2011. Five came from Vietnam; 2 each came from Bangladesh and Indonesia; and 1 each from Hong Kong, Myanmar, and Ukraine. Their illnesses started at a mean age of 1.5 years (0.1 to 6.6) and they had been receiving blood transfusion for a mean duration of 2.5 years (0.1 to 9.9) years prior to the evaluation. Thalassemia major was the fi rst diagnosis in 5 cases; one had been treated for autoimmune haemolytic anaemia while the rest had not been given a diagnosis. After the evaluation, 4 children were diagnosed with Diamond Blackfan anaemia, 3 were diagnosed with hereditary spherocytosis, and one each with hereditary pyropoikilocytosis, congenital sideroblastic anaemia, congenital thrombotic thrombocytopenic purpura, transient erythroblastopenia of childhood, and autoimmune myelofibrosis associated with human immunodeficiency virus infection. CONCLUSION: A definitive diagnosis can be identified in this cohort of children on medical tourism with severe anaemic illnesses requiring repeated transfusions with diagnostic approaches that circumvent the interference of transfused cells.

A 3-bp deletion in the HBS1L-MYB intergenic region on chromosome 6q23 is associated with HbF expression.

Fetal hemoglobin (HbF) is regulated as a multigenic trait. By genome-wide association study, we confirmed that HBS1L-MYB intergenic polymorphisms (HMIP) and BCL11A polymorphisms are highly associated with HbF in Chinese ß-thalassemia heterozygotes. In this population, the variance in HbF resulting from the HMIP is 13.5%; that resulting from the BCL11A polymorphism is 6.4%. To identify the functional variant in HMIP, we used 1000 Genomes Project data, single nucleotide polymorphism imputation, comparisons of association results across populations, potential transcription factor binding sites, and analysis of phylogenetic conservation. Based on these studies, a hitherto unreported association between HbF expression and a 3-bp deletion, between 135 460 326 and 135 460 328 bp on chromosome 6q23 was found. This 3-bp deletion is in complete linkage disequilibrium with rs9399137, which is the single nucleotide polymorphism in HMIP most significantly associated with HbF among Chinese, Europeans, and Africans. Chromatin immunoprecipitation assays confirmed erythropoiesis-related transcription factors binding to this region in K562 cells. Based on transient expression of a luciferase reporter plasmid, the DNA fragment encompassing the 3-bp deletion polymorphism has enhancer-like activity that is further augmented by the introduction of the 3-bp deletion. This 3-bp deletion polymorphism is probably the most significant functional motif accounting for HMIP modulation of HbF in all 3 populations.

Molecular diagnosis of severe combined immunodeficiency--identification of IL2RG, JAK3, IL7R, DCLRE1C, RAG1, and RAG2 mutations in a cohort of Chinese and Southeast Asian children.

Severe combined immunodeficiencies (SCID) are a group of rare inherited disorders with profound defects in T cell and B cell immunity. From 2005 to 2010, our unit performed testing for IL2RG, JAK3, IL7R, RAG1, RAG2, DCLRE1C, LIG4, AK2, and ZAP70 mutations in 42 Chinese and Southeast Asian infants with SCID adopting a candidate gene approach, based on patient's gender, immune phenotype, and inheritance pattern. Mutations were identified in 26 patients, including IL2RG (n = 19), IL7R (n = 2), JAK3 (n = 2), RAG1 (n = 1), RAG2 (n = 1), and DCLRE1C (n = 1). Among 12 patients who underwent hematopoietic stem cell transplantation, eight patients survived. Complications and morbidities during transplant period were significant, especially disseminated bacillus Calmette-Guérin disease which was often difficult to control. This is the first cohort study on SCID in the Chinese and Southeast Asian population, based on a multi-centered collaborative research network. The foremost issue is service provision for early detection, diagnosis, management, and definitive treatment for patients with SCID. National management guidelines for SCID should be established, and research into an efficient platform for genetic diagnosis is needed.

Double heterozygosity for Hb New York [beta 113 GTG-->GAG; VAL-->GLU] and beta degrees-thalassemia mutations manifests as a thalassemia trait.

An extended family with three individuals affected by two different forms of double heterozygosity for beta-thalassemia and Hb New York is reported. Double heterozygosity of Hb New York [beta 113 GTG-->GAG; VAL-->GLU] and beta degrees codon 17 was detected in a fetus following prenatal screening for thalassemia. The father and a paternal aunt were also found to be heterozygous for Hb New York and beta degrees IVSII-654. Both adults had clinical and hematological features consistent with beta-thalassemia trait. The affected child was followed up after birth and manifested the typical course of a thalassemia trait, with no signs of organomegaly or overt hemolysis. Observations strongly suggest that double heterozygosity of Hb New York and beta degrees thalassemia has mild, if any, clinical symptoms, and is not an indication of therapeutic abortion when detected antenatally.

Variation and heritability of Hb F and F-cells among beta-thalassemia heterozygotes in Hong Kong.

Enhanced fetal hemoglobin (Hb F) production can partially compensate for the lack of adult hemoglobin (Hb A) in patients with beta-thalassemia major or intermedia, and ameliorate the clinical severity of these diseases. To further elucidate factors governing Hb F levels, we evaluated demographic, clinical, laboratory, and genetic characteristics in 241 unrelated adult beta-thalassemia carriers in Hong Kong. They had wide variations in Hb F and F-cell numbers skewing toward higher levels. Individuals who coinherited the Xmn IT-allele in the (G)gamma-globin gene promoter had higher Hb F and more F-cells compared with those lacking the Xmn I T-allele. However, both groups exhibited a similarly wide spread of Hb F and F-cells. The correlation of Hb F and F-cells corresponded well to both linear and exponential models, suggesting multiple mechanisms for Hb F augmentation. The heritabilities of Hb F and F-cells were calculated in 66 families (111 parents who were beta-thalassemia carriers and 82 asymptomatic offspring) to be 0.7 to 0.9. The Xmn I polymorphism accounted for 9% of the Hb F and 13% of the F-cell heritabilities. These results suggest that these family members are well suited for genome wide association studies that will identify genetic loci regulating Hb F production, and likely novel pharmacological targets for reactivating Hb F production in adults.

Severe coagulopathy associated with white-lipped green pit viper bite.

The authors report a case of Trimeresurus albolabris (white-lipped green pit viper) bite in a 6-year-old girl living in rural Yuen Long. Despite repeated use of Agkistrodon halys antivenin, the patient developed severe coagulopathy with defibrination syndrome on the fourth day of envenomation, which was also refractory to therapy with fresh frozen plasma. When treatment was switched to green pit viper antivenin, the coagulopathy resolved promptly. The case is illustrative of the potential lethality to children of snakebites in Hong Kong and suggests that the A halys antivenin may not be effective for the treatment of T albolabris bites.

A novel beta-delta globin gene fusion, anti-Lepore Hong Kong, leads to overexpression of delta globin chain and a mild thalassaemia intermedia phenotype when co-inherited with beta(0)-thalassaemia.

Anti-Lepore haemoglobins (Hb) are rare betadelta fusion variants that arise from non-homologous crossover during meiosis, resulting in a delta-betadelta-beta configuration. A novel anti-Lepore mutation (anti-Lepore Hong Kong) was found in two Chinese families with raised Hb A(2). Direct sequencing revealed a crossover within a 54-bp region spanning the junction of cap site (CAP) and exon 1, which predicted the production of normal delta-globin. Determination of alpha/beta-mRNA ratios by quantitative real-time polymerase chain reaction demonstrated downregulation of the beta gene in cis due to the interposed betadelta fusion gene. Although heterozygotes have normal red cell indices and are clinically silent, compound heterozygotes with beta(0) mutation in trans produce a mild thalassaemia intermedia phenotype with a markedly raised Hb A(2) level that may mimic clinically mild Hb E-beta(+)-thalassaemia. Awareness of the presence of anti-Lepore Hong Kong will help to resolve diagnostic problems in regions with significant prevalence of globin disorders.

Elective removal of cuffed central venous catheters in children.

BACKGROUND: Subcutaneously tunneled, cuffed central venous catheters (CVCs) are commonly used in children undergoing cytotoxic chemotherapy or hematopoietic stem-cell transplantation. When their use is no longer indicated or precluded by mechanical or infectious complications, CVCs have to be removed. General instructions on how cuffed CVC should be removed are available in the medical texts but none is adapted for use in children. MATERIALS AND METHODS: A literature search from the MEDLINE and EMBASE to identify articles describing the procedure of removing CVC or complications arising from the procedure was carried out. RESULTS: Specific guidance on the removal of CVC in children was not found. Venous air embolism appeared to be the most common complication associated with catheter removal but none involved pediatric patients. On the other hand, three out of the five incidents of catheter fracture with or without embolization happened in children. CONCLUSION: Further studies are needed to define the optimal management of CVC removal in pediatric patients. A sequence of positioning the child, use of sedation, dissecting out the cuff, pulling off the catheter, closing the exit wound, and handling of the removed catheter is suggested.

Intraspinal and intracranial hemorrhage after lumbar puncture.

Two cases of spinal epidural hematoma and two cases of intracranial subdural hematoma after lumbar puncture (LP) are reported in children receiving chemotherapy for acute lymphoblastic leukemia and non-Hodgkin lymphoma. The bleeding was asymptomatic but interfered with treatment in one case, and caused either severe backache or headache but no neurological deficit in the other three patients. The platelet counts were 8 and 46 x 10(9)/L in two patients and were normal in the other patients at the time of LP. All recovered without surgical treatment. There is an inherent, albeit uncommon, risk of bleeding into the central nervous system associated with LP in children with cancer and should be distinguished from postdural puncture headache (PDPH). Thrombocytopenia is not always an accompanying factor.

The impact of a management protocol on the outcomes of child abuse in hospitalized children in Hong Kong.

OBJECTIVE: To study the outcomes of children hospitalized for suspected child abuse before and after the implementation of a management protocol in a hospital in Hong Kong. STUDY PERIOD: Two 2-year periods before (1994-1995) and after (2002-2003) the implementation of the protocol in 1998. METHODS: This is a retrospective hospital chart review in which the patients' characteristics, the use of laboratory and radiological examination, abuse substantiation and official registrations are compared between the two study periods. RESULTS: There were 109 and 320 patients admitted for evaluation of child abuse for the periods 1994-1995 and 2002-2003, respectively. Children in both periods were similar in sex ratio, proportion of severe forms of child abuse, rates of abuse substantiation and inclusion in the Child Protection Registry. After the implementation of a management protocol, there has been a significant drop in the proportion of children subjected to investigations such as blood counts (86% vs. 16%, p<.001), clotting study (75% vs. 9%, p<.001), and skeletal survey (78% vs. 6%, p<.001). The average length of hospital stay also dropped from 15.3 days to 6.1 days (p<.001). CONCLUSIONS: There has been an almost threefold rise in the number of child abuse cases handled at the hospital during the 10-year interval. With the implementation of a management protocol, only a small proportion of children need laboratory investigations or skeletal survey without any drop in abuse substantiation and official registration. The length of hospital stay has also been significantly reduced.

A randomized controlled study evaluating the safety and efficacy of deferiprone treatment in thalassemia major patients from Hong Kong.

A controlled, open-label and randomized study was conducted to evaluate the safety and efficacy of the oral iron chelator deferiprone (L1) in thalassemia major patients from Hong Kong. Forty-nine patients were recruited in total (median age: 20 years; range: 8 to 40 years). The division of the patients was determined based on liver iron content and put into either the poorly-chelated (Group I) or well-chelated (Group II) groups. In Group I, 20 patients received combined therapy of L1 daily plus desferrioxamine (DFO), in a reduced frequency of twice weekly, while the control group consisted of 16 patients who were treated with DFO alone. In Group II, six patients received L1 only, while the control group consisted of seven patients treated with DFO alone. Only patients who participated for longer than 6 months were analyzed for efficacy (n = 44). The median study period was 18 months. Transient and mild gastrointestinal upset (31%), joint pain (15%) and liver enzyme elevation (23%) were the most common side effects noted for L1. No case of neutropenia was observed in this study. Serum ferritin (SF) levels showed significant decline in the poorly-chelated patients using combined therapy (L1 and reduced frequency DFO) as compared to those on DFO alone. However, their pre- and post-study liver iron content was not significantly different. Evaluation of the well-chelated group demonstrated no significant change in SF or liver iron content in both the study and control arms. We conclude that the short-term use of L1, with or without DFO, was safe and efficacious in our Chinese patient cohort. The long-term efficacy of reducing iron overload by treatment regimens including L1 requires further study.

High-dose methotrexate-associated acute renal failure may be an avoidable complication.

A 17-year-old boy with acute lymphoblastic leukemia developed acute renal failure within 48 h of an intravenous high-dose methotrexate (5 g/m2) infusion. His renal function returned to baseline 14 days later with supportive care, folinic acid rescue, and urinary alkalinization. A retrospective review revealed that the patient had been exposed to iopamidol, an intravenous contrast medium, on the day prior to the commencement of methotrexate treatment. Methotrexate-associated nephropathy is a rare complication in pediatric oncology, and a review of the literature suggests that exposure to nephrotoxic agents may be a significant but perhaps underrecognized risk factor for its development.

Managing patients with identical names in the same ward.

PURPOSE: To review the experience of managing two patients with identical names in the same ward during a five-month period. DESIGN/METHODOLOGY/APPROACH: The records of the patients were reviewed to look for incorrect entries, errors in specimens sampling, administration of blood products and chemotherapy, and misplacement of clinical notes. Doctors and nurses involved were also invited to complete a questionnaire study to comment on the usefulness of the measures implemented for correct patient identification. A random sample of 60 patients was also selected to see if their full names were shared with other patients attending the same hospital. FINDINGS: Among the 1442 sheets of hospital records from the two patients, no errors pertaining to the clinical activities were found. However, 13 (0.9 per cent) sheets of the hospital records were misplaced. The 21 doctors and nurses participating in the questionnaire study gave positive support to all the additional measures implemented for safeguarding patient identification, of which the automated alerting feature in the electronic clinical management system received the highest scores. A total of 32 (53 per cent) of the 60 sampled patients shared a common full name with one to 101 other patients attending the same hospital. ORIGINALITY/VALUE: Patients with identical names staying in the same ward present a unique challenge to acute health-care settings. The situation is especially relevant in communities where most people's names are not unique. Specific guidelines and measures are needed to prevent patient misidentification. Errors in filing of patient notes and laboratory reports to the hospital record deserve further attention.

Isolated foot ulcer complicating acute leukemia: an unusual manifestation of herpes simplex virus infection simulating pyoderma gangrenosum.

An isolated foot ulcer developed in a child with newly diagnosed acute mixed lineage leukemia during induction chemotherapy. Despite its clinical resemblance to pyoderma gangrenosum, herpes simplex virus infection was eventually diagnosed on histopathology. Treatment with oral acyclovir was ineffective, but the ulcer healed with intravenous acyclovir followed by oral valaciclovir. Viral infection remains an unusual but important cause of isolated extragenital cutaneous ulceration in the immunocompromised child.