One man, one disease?

We report the case of a 12-year-old girl with a strong family history of malignancy who presented with immature teratoma and gliomatosis peritonei. Despite first and second line chemotherapy, the disease ran an unusually refractory course. Although the presentation was not the typical tumour presentation of Li-Fraumeni syndrome (LFS), we proceeded to undertake tumour genetic testing of the patient and her parents. LFS was diagnosed in this patient and her father with a sequence variation of CGG>TGG, R248W, which is one of the most common transcriptionally inactive mutations detected in LFS. Genetic counselling was offered to the father. A tumour screening programme and genetic screening for the p53 gene mutation for the surviving family members can be offered once consent is obtained from the father. This case illustrates the importance of cancer genetic study, even if the tumour presentation is not typical for any familial cancer syndrome.

Improved outcome of acute lymphoblastic leukaemia treated by delayed intensification in Hong Kong children: HKALL97 study.

OBJECTIVE: To study the outcome of children with acute lymphoblastic leukaemia who were treated using a protocol including one or two delayed intensifications. DESIGN: Prospective single-arm multicentre study. SETTING: Five designated children cancer units of the Hospital Authority of Hong Kong. PATIENTS: Children aged between 1 and 17.9 years with newly diagnosed acute lymphoblastic leukaemia seen from November 1997 to December 2002. INTERVENTION: Chemotherapy was modified from a German Berlin-Frankfurt-Muenster 95 (BFM95) protocol that included a delayed intensification similar to the induction phase repeated 5 months after diagnosis. High-risk patients were given double delayed intensification. MAIN OUTCOME MEASURES: Overall survival and event-free survival of the whole group and the three risk groups (standard-, intermediate-, and high-risk groups), and comparison with historical controls. RESULTS: A total of 171 patients were recruited with a median age at diagnosis of 5.57 years (range, 1.15-17.85 years). The induction remission rate was 95.3% and non-leukaemia mortality during remission was 2.3%. At 4 years, the relapse rate of this (HKALL97) study was significantly lower than that of the HKALL93 study (15.7 vs 37.3%; P<0.001). The 4-year overall survival of HKALL97 and HKALL93 studies were 86.5% and 81.8%, respectively (P=0.51). The 4-year event-free survival for HKALL97 and HKALL93 studies were 79% and 65%, respectively (P=0.007). Nonetheless the difference of event-free survival was most remarkable in the intermediate-risk group: 75.6% and 53.1% for HKALL97 and HKALL93 studies, respectively (P=0.06). CONCLUSION: A more intensive delayed consolidation phase improved the outcome for children with acute lymphoblastic leukaemia by reducing relapses at 4 years. The early treatment complications were manageable and non-leukaemia mortality during remission remained low.

Bone mineral density in children with thalassaemia major: determining factors and effects of bone marrow transplantation.

Osteoporosis and osteopenia affect up to half of patients with thalassaemia major (TM). We investigate the effects of acquired factors and BMT on bone mineral density (BMD) in these patients. In all, 53 patients on regular transfusion (BT group) and 33 patients at 5.7+/-1.9 years post transplant (BMT group) were recruited. BMD was measured by dual energy X-ray absorptiometry. Serum concentrations of osteocalcin, bone-specific alkaline phosphatase (ALP), beta-crossLap and urinary cross-linking deoxypyridinoline (DPD) were measured by chemiluminescence and enzyme immunoassay, respectively. Severe BMD deficit (Z-score <-2.5) at spine and hip were noted in 62 and 35% of BT group. Serum osteocalcin (beta=-0.463; P=0.006) was predictive of spine BMD, whereas age (beta=-0.843; P=0.007) and urine DPD (beta=-0.439; P=0.037) were associated with hip BMD in BT group. Among BMT patients, post transplant duration (beta=0.450; P=0.009) and serum bone-specific ALP (beta=-0.495; P=0.013) were associated with spine BMD. Severe BMD deficit was less common among BMT than BT patients (6 vs 35%; P=0.036). The mean (s.d.) osteocalcin levels in BMT and BT groups were 96.4 (72.7) microg and 68.9 (40.3) microg/l, respectively (P=0.037). In conclusion, severe BMD deficit is common in Chinese TM patients and BMT may reverse BMD deficit in these patients.

Unrelated umbilical cord blood transplantation in children: experience of the Hong Kong Red Cross Blood Transfusion Service.

OBJECTIVE: To review the outcome of unrelated umbilical cord blood transplantation in children using cord blood from the Hong Kong Red Cross Blood Transfusion Service. DESIGN: Retrospective study. PATIENTS: Records of eight patients who received unrelated umbilical cord blood transplants between 1999 and 2003 were reviewed. MAIN OUTCOME MEASURES: Engraftment of haematopoietic cells and graft-versus-host disease after transplantation. RESULTS: The median age of the patients was 4.9 years (range, 1.0-9.4 years). Five patients had acute leukaemia, one had non-Hodgkin's lymphoma, one had X-linked adrenoleukodystrophy, and one had mucolipidosis. The infused umbilical cord blood units contained a median of 6.7 x 10(7) /kg nucleated cells and 4.0 x 10(5) /kg CD34-positive cells. Neutrophil engraftment was achieved at a median of 13 days (range, 11-19 days) and, for seven patients, platelet engraftment was achieved at a median of 39 days (range, 24-98 days). Acute graft-versus-host disease occurred in all patients (grades I to III). One of the patients died because of encephalitis; of the other seven, five developed chronic graft-versus-host disease of the skin. At a median follow-up of 2 years, the four patients with leukaemia and the one with non-Hodgkin's lymphoma remained in continuous complete remission; the patient with adrenoleukodystrophy showed stabilisation of neurological condition. CONCLUSION: The Hong Kong Red Cross Blood Transfusion Service Cord Blood Bank stored cord blood units of good quality for transplantation, the outcome of which was comparable to that of bone marrow transplantation.

Oseltamivir prophylaxis during the influenza season in a paediatric cancer centre: prospective observational study.

OBJECTIVE: To determine the role of oseltamivir prophylaxis for immunocompromised patients. DESIGN: Prospective, non-blinded, non-controlled observational study. SETTING: A paediatric cancer centre, Hong Kong. PARTICIPANTS: Thirty-two patients, immunocompromised by chemotherapy or bone marrow transplantation during an influenza season in 2001. INTERVENTION: Oral oseltamivir prophylaxis 75 mg/d for 8 weeks. MAIN OUTCOME MEASURES: Laboratory-confirmed influenza infection, symptoms of influenza, drug compliance, and any side-effects from oseltamivir treatment. Laboratory monitoring included virological surveillance for influenza A and B, blood counts, and renal and liver function tests. RESULTS: Patients' median age was 14.3 years (range, 6.3-23.4 years). Underlying conditions included malignancy (n=29) and other haematological diseases (n=3). No documented influenza infection according to serological tests was present throughout the study period. Five patients with symptoms of upper respiratory tract infection did not have any influenza infection detected by rapid virological assay and viral culture. For 16% of patients, the main side-effect in the study was gastro-intestinal upset. CONCLUSIONS: Oral oseltamivir 75 mg once daily for 8 weeks may be useful in the prevention of influenza infection in patients immunocompromised by chemoradiotherapy; side-effects are few and acceptable.

Treatment of acute lymphoblastic leukemia in Hong Kong children: HKALL 93 study.

A population-based multicentre study for childhood acute lymphoblastic leukemia (ALL) was conducted in Hong Kong from 1993 to 1997. One hundred and forty-five newly diagnosed ALL patients were treated by the HKALL 93 protocol. Patients were stratified into three risk groups according to age, presenting white cell count, immunophenotyping and cytogenetic study. The patients received the same induction and early and late intensification at week 5 and week 20. Fifty-eight standard risk (SR) patients received regular intrathecal methotrexate as CNS preventive therapy, while 49 intermediate risk (IR) patients received high dose intravenous methotrexate and regular intrathecal methotrexate. Thirty-eight high risk (HR) patients were treated with prophylactic cranial irradiation and an additional intensification block at week 35. The induction remission rate was 97.2% with 2% induction death. Two patients died during first complete remission. Relapse occurred in 20.7, 42.9 and 42.1% of SR, IR and HR patients respectively. By multivariate logistic regression, age> or =10 years and white cell count> or =100 x 10(9)/l were the two significant variables accounting for mortality. The 5-year overall and event-free survival of the whole group was 81.3 and 62.6% respectively. According to risk groups, the event-free survival was 79, 49 and 61% for SR, IR and HR patients respectively, while the overall survival was 96, 73 and 68% for SR, IR and HR patients respectively. In conclusion, the treatment protocol had low treatment-related mortality but was associated with a rather high relapse rate, especially in IR patients. Salvage therapy achieved sustained second remission in some patients. More intensive treatment especially a late intensification is required to improve the outcome.

Human herpesvirus-6 encephalitis after unrelated umbilical cord blood transplant in children.

Three children developed human herpesvirus-6 (HHV-6), variant B encephalitis after unrelated umbilical cord blood transplant, in a single center. They developed clinical manifestations of encephalitis around day 17 post transplant. Impairment of consciousness, incoherent speech, episodic focal pruritus, motor weakness, convulsions and severe hyponatremia were features at presentation. Radiological investigation of brain ranged from unremarkable to extensive white matter and meningeal lesions. Diagnosis was established by the presence of HHV-6 DNA in cerebrospinal fluid (CSF). Retrospective analyses of plasma revealed the presence of viral DNAemia prior to the onset of disease in two subjects. Treatment with ganciclovir or foscarnet was given. Two subjects did not achieve engraftment and died of other transplant-related complications on day 38 and 56 post-transplant, respectively. One subject achieved disease-free survival for more than 1 year with a satisfactory neurological outcome. In conclusion, HHV-6 encephalitis is not uncommon among patients undergoing umbilical cord blood transplantation. It is worth conducting further studies on early diagnosis and optimal management of this potentially fatal disease.

Liver disease in transfusion dependent thalassaemia major.

AIMS: To study the prevalence and severity of liver diseases of transfusion dependent thalassaemia major patients, and correlate the histological and biochemical changes of iron overload in liver with the peripheral blood markers. METHOD: Liver biopsy was performed to assess the histological changes and liver iron content (LIC). RESULTS: One hundred patients were evaluated (median age 11.7 years, range 1.5-27). A total of 81 liver biopsies were performed in 73 patients; 43 samples were analysed for LIC. Grade 3-4 haemosiderosis and hepatic fibrosis was found in 44% and 30% of patients respectively; both were significantly associated with higher serum ferritin, liver enzymes, and LIC. Very high LIC (>15 mg/g dry weight) was present in 16.3% of patients. CONCLUSION: Severe haemosiderosis and hepatic fibrosis were common in patients with thalassaemia major despite the use of chelation therapy. Liver biopsy provided information on fibrosis and LIC which could not be accurately predicted from peripheral blood markers.

Haematopoietic stem cell transplantation for thalassaemia major in Hong Kong: prognostic factors and outcome.

From August 1992 to August 1999, 44 patients received allogeneic haematopoietic stem cell transplantation in a single institution. The donors were HLA-identical siblings except for one who was a phenotypically matched father. Thirty-eight patients received bone marrow stem cells and the others received peripheral blood stem cells or umbilical cord blood (UCB). The mean age at transplant was 10.7+/-5.1 years, ranging from 1.8 to 21 years. Patients received busulphan (16 mg/kg) and cyclophosphamide (150 to 200 mg/kg) as conditioning, and antithymocyte globulin was given to 42 patients to prevent graft rejection. All had engraftment except a patient who received a UCB transplant. Four patients died from early treatment-related mortality, and one died from interstitial pneumonitis 3 months after transplant. Two patients developed secondary graft rejection and both received a second transplant. Thirty-eight patients survived and all except one were transfusion independent. The 5-year overall and event-free survival rates were 86% and 82%, respectively. By multivariate stepwise Cox proportional hazard analyses, severe veno-occlusive disease (VOD) of liver and Pesaro class 3 features were the significant factors associated with survival. Patients aged more than 11 years were more inclined to develop VOD. In conclusion, haematopoietic stem cell transplantation should be performed early if an HLA identical sibling is available.

TEL/AML1 rearrangement and the prognostic significance in childhood acute lymphoblastic leukemia in Hong Kong.

The TEL/AML1 rearrangement has been implicated as an independent good prognostic factor in pediatric acute lymphoblastic leukemia (ALL). We examined TEL/AML1 using nested reverse-transcription polymerase chain reaction (RT-PCR) and correlated TEL/AML1 with cytogenetics and immunophenotypes in 75 consecutively analyzed Chinese children with ALL in Hong Kong. TEL/AML1 was detected in 17.9% (12/67) B-lineage ALL at diagnosis but not in 8 T-ALL children or in 34 adults with ALL. E2A/PBX1, MLL/AF4, and BCR/ABL were not found in TEL/AML1+ patients. Coexpression of cross-lineage antigens was associated with TEL/AML1 gene fusion (p = 0.032), with CD13 in 80% (4/5) TEL/AML1+ cohort. Chromosomal abnormalities were demonstrated in 50% of the TEL/AML1+ ALL; however, a cryptic t(12;21) was not detected in these cases. Hyperdiploidy of 47-48 chromosomes was encountered in 25%. Deletion of 12p resulting in the loss of the normal allele of TEL and nonspecific del(6q) were noted in 8% (1/12) and 25% (3/12) of the TEL/AML1+ children, respectively. Rapid clearance of TEL/AML1 was noted in 50% of the patients on completion of the induction therapy; however, 16.7% (2/12) TEL/AML1+ ALL relapsed at a mean of 48.6 months from diagnosis (25 months off-therapy). The incidence of relapses of TEL/AML1+ ALL was comparable to that at diagnosis in B-lineage ALL (14.3% [2/14] vs. 17.9% [12/67], p > 0.05). The relapse rate in TEL/AML1+ ALL was similar to that of TEL/AML1- ALL (16.7% [2/12] vs. 20.6% [13/63], p > 0.05). The duration of first complete remission in TEL/AML1+ ALL was significantly longer as compared to TEL/AML1- ALL (mean [range] in month: 48.6 [47.2 - 50] vs 14.6 [2.9 - 42.3], p < 0.0001). Irrespective of TEL/AML1 rearrangement, the probabilities of the five-year overall survival and the event-free survival of patients were comparable (overall survival: 100% vs. 72.3%, p = 0.166 and event-free survival: 60% vs. 56.2%, p = 0.343). Our data would not suggest a less aggressive treatment regimen for TEL/AML1+ ALL.

Klebsiella pneumoniae meningitis in thalassemia major patients.

Two thalassemia major patients received regular blood transfusion and desferrioxamine chelation, and 1 patient had a splenectomy at 9 years of age. Both patients developed Klebsiella pneumoniae meningitis at age of 27 and 15 years. They died within a short time despite appropriate antibiotic treatment. Klebsiella meningitis may be more common in transfusion-dependent thalassemia patients.

Clearance of TT virus after allogeneic bone marrow transplantation.

A 10-year-old girl with thalassemia underwent bone marrow transplantation. Before transplantation, she had persistent TT virus (TTV) DNAemia for at least 18 months. Interestingly, the viral DNAemia was cleared soon after transplant and remained undetectable at the latest follow-up at 28 months. The early clearance of TTV that had occurred before engraftment or initiation of any antiviral therapy, together with the absence of TTV DNA from the results of the liver biopsy performed before transplantation, led us to hypothesize that the hematologic compartment could have been the site for viral persistence. Thus, the conditioning regimen may have depleted the hemic cells and the hematologically compartmentalized TTV. The potential of hemic tropism of TTV and its role in hematologic diseases need to be considered.

Alpha-fetoprotein variants in a case of pancreatoblastoma.

We describe a 6-year-old boy with histologically confirmed pancreatoblastoma and a markedly elevated serum alpha-fetoprotein (AFP) concentration. Due to local tumour invasion, cytotoxic chemotherapy was given to debulk the tumour before attempting surgical resection. Serial serum AFP concentrations were measured on this patient. During chemotherapy there was a > 95% fall in total AFP. Tumour-specific variants of AFP, detected by isoelectric focusing, also disappeared during chemotherapy but recurred when chemotherapy was withdrawn. It is suggested that although there was no change in overall size of the tumour, as assessed by various imaging techniques, the changes in serological markers may indicate that the treatment did in fact cause considerable tumour necrosis, AFP and its variants may be useful markers of tumour response in patients with pancreatoblastoma. The expression of AFP and its variants in pancreatoblastoma may be related to the embryonic origin of the pancreas.

Umbilical cord blood transplantation for Maroteaux-Lamy syndrome (mucopolysaccharidosis type VI).

Severe Maroteaux-Lamy syndrome (mucopolysaccharidosis type VI) is usually fatal by early adulthood. Bone marrow transplantation is the only form of definitive enzyme replacement therapy available. A 5-year-old boy with Maroteaux-Lamy syndrome has successful recovery of bone marrow and enzymatic functions after umbilical cord blood transplant from his unaffected HLA-identical brother. Busulphan (16 mg/kg) and cyclophosphamide (200 mg/kg) were used as preparative chemotherapy with short methotrexate and long cyclosporin as prophylaxis against graft-versus-host disease (GVHD). A total of 6.08 x 10(7)/kg nucleated cells and 2.92 x 10(5)/kg CD34+ cells were transplanted with neutrophil engraftment achieved on day 26. There was no evidence of acute and chronic GVHD. Fifteen months after transplant, a normal level of N-acetylgalactosamine-4-sulphatase activity was achieved despite mixed chimerism. There was clinical improvement of hepatosplenomegaly, facial and skin features, joint mobility and resolution of suppurative middle ear effusion. He returned to school and continued to perform well in academic studies. We report here the first successful umbilical cord blood transplant as treatment of Maroteaux-Lamy syndrome.

Single vs twice daily G-CSF dose for peripheral blood stem cells harvest in normal donors and children with non-malignant diseases.

The optimal dose and schedule of G-CSF for mobilization of peripheral blood stem cells (PBSC) is not well defined. G-CSF mobilization was performed in a group of healthy donors and paediatric patients for autologous back-up before receiving allogeneic stem cell transplant. Seventeen consecutive subjects who received G-CSF at 5 microg/kg/dose twice daily (group A) were compared with a historical control group of 25 subjects who received a single daily dose of 10 microg/kg/day G-CSF (group B). Double blood volume apheresis for PBSC collection was started on day 5. G-CSF was continued and apheresis repeated until the targeted CD34+ cell dose was achieved. Both groups were comparable for sex, age, body weight and reason for PBSC collection. Over two-thirds of the subjects in both groups were less than 16 years of age. The G-CSF priming and apheresis were well tolerated. When the first day apheresis products were analyzed, group A resulted in significantly higher yield of total nucleated cells (5.91 vs 3.92 x 108/kg, P = 0. 013), mononuclear cells (5.73 vs 3.92 x 108/kg, P = 0.017), CD34+ cells (2.80 vs 1.69 x 106/kg, P = 0.049) and colony-forming units (107 vs 54 x 104/kg, P = 0.010) as compared with group B. We conclude that the two dose schedule is more efficient in mobilizing PBSC in normal donors and children with non-malignant diseases. This approach may reduce the number of aphereses required and thus reduce the transplant cost.

Up-regulation of cell growth associated with an extra Y chromosome in a child with beta-thalassemia major having undergone hematopoietic stem cell transplant.

An extra Y chromosome(s) is occasionally found in patients with various hematologic neoplasias; however, an association with hereditary blood diseases is unknown. In a child with beta-thalassemia who received a transplant with sex-mismatched umbilical cord blood and neonatal blood, fluorescent in situ hybridization (FISH) with probes to X and Y chromosomes revealed an extra Y signal in 19.3% of the hepatocytes and in 38.9% of the pretransplant peripheral blood cells, yielding YY/Y ratios of 0.24 and 0.64, respectively. In granulocyte colony-stimulating factor-mobilized autologous peripheral blood stem cells, the FISH ratio of interphase XYY cells to XY cells was 1.64, and there were 3.4 times more G-banded XYY metaphases than normal metaphases. Both FISH and polymerase chain reaction persistently demonstrated posttransplant mixed chimerism. There was a greater proportion of residual autologous XYY cells than XY cells with a mean posttransplant YY/Y ratio of 1.56 (n = 13) (1 SD = 0.33; range, 1.10 to 2.17). In vitro clonogenic assays yielded a normal number of colony-forming units but no growth in cultures without growth factor supplement. This study suggests that hematopoietic stem cells with an extra Y chromosome may upregulate cell growth in response to cytokine stimulation. A posttransplant preponderance of XYY cells might be attributable to an extra Y chromosome in hematopoietic stem cells withstanding the myeloablative conditioning regimen.

Early iron reduction programme for thalassaemia patients after bone marrow transplantation.

Thirty thalassaemia patients received iron reduction starting at around 3 months post transplant. Sixteen received desferrioxamine and nine had phlebotomy, five patients had desferrioxamine followed by phlebotomy. The desferrioxamine group had higher serum ferritin levels at the start of iron reduction as compared to the phlebotomy group (5292 vs 2453 microg/l, P EQ 0.001). After 444 and 407 days of iron reduction, serum ferritins at cessation of iron reduction in both groups was similar (665 vs 588 microg/l). The rate of decline of serum ferritin in both groups was similar. There was no graft rejection during the programme. Early institution of iron reduction in ex-thalassaemia is safe.

Incidence, risk factors and outcome of varicella-zoster virus infection in children after haematopoietic stem cell transplantation.

We report a retrospective analysis of VZV infection after haematopoietic stem cell transplantation (HSCT) in children. Thirty-three (30%) of the total 109 children who were transplanted during a 7 year period developed post-transplant VZV infection. Twenty-four of these 33 (73%) children had VZV infection within 1 year following HSCT. The cumulative incidences of post-transplant VZV infection at 1 and 5 years were 26% and 45%, respectively. The positive and negative predictive values of pretransplant VZV serology in recipients on the development of HZ following HSCT were 39% and 88%, respectively. Pretransplant VZV seropositivity in recipients was the only risk factor for post-transplant herpes zoster (HZ) infection on multivariate analysis. All patients responded to acyclovir. The median duration of VZV infection was 5 days. Three (11%) and one (3%) children with HZ developed visceral dissemination and post-herpetic neuralgia, respectively. No mortality was directly attributed to VZV infection. VZV infection remains a major cause of morbidity in children after HSCT. Further studies are warranted to evaluate the potential use of VZV vaccine in these children. Bone Marrow Transplantation (2000) 25, 167-172.