No evidence of significant silencing of Fanconi genes FANCF and FANCB or Nijmegen breakage syndrome gene NBS1 by DNA hyper-methylation in sporadic childhood leukaemia

Fanconi anaemia (FA) and Nijmegen breakage syndrome (NBS) carry a high risk of haematological cancer. Affected cellular pathways may be modulated in sporadic malignancies and silencing of FANCF through methylation has been shown to cause somatic disruption of the FA pathway. Combined bisulphite restriction analysis for methylation of FANCF, FANCB and NBS1 was used to investigate 81 sporadic acute childhood leukaemias. No methylation was detected at any associated CpG sites analysed. This does not exclude very low levels of FANCF, FANCB or NBS1 methylation, but suggests other factors are responsible for chemo-sensitivity and chromosomal instability in sporadic childhood leukaemia.

Association of acute parvovirus B19 infection with new onset of acute lymphoblastic and myeloblastic leukaemia

AIMS

To investigate the association of acute parvovirus B19 infection with new onset of acute lymphoblastic and myeloblastic leukaemia.

METHODS

Cerebrospinal fluid (CSF) samples from patients with acute myelogenous leukaemia (AML) at diagnosis (n = 2) and acute lymphoblastic leukaemia (ALL) at diagnosis (n = 14) were analysed for parvovirus B19 DNA by means of nested polymerase chain reaction. In addition, samples from patients with benign intracranial hypertension (BIH) (n = 10) and hydrocephalus (n = 13) were tested as controls.

RESULTS

Four leukaemia cases were positive-common ALL (n = 2), null cell ALL (n =1), and M7 AML (n = 1)-whereas all controls were negative (Yates corrected chi(2) value, 3.97; p = 0.046; odds ratio, 16.92; confidence interval, 1.03 to 77.18). All four patients were significantly anaemic, but none was encephalitic or had evidence of central nervous system leukaemia. In three of these patients, serum tumour necrosis alpha, interferon gamma, interleukin 6, granulocyte-macrophage colony stimulating factor (range, 34.93-3800.06 pg/ml), and macrophage chemoattractant protein 1 were detectable. All of these four patients carried at least one of the HLA-DRB1 alleles, which have been associated with symptomatic parvovirus B19 infection.

CONCLUSION

Erythroid suppression and immune cell proliferation are both associated with B19 infection and may also be important in the pathogenesis of acute leukaemia.

Transient lymphopenia in acutely unwell young infants

The clinical outcome of 42 acutely unwell infants <3 months old with lymphopenia was retrospectively compared with that of 42 controls. Lymphopenic infants were significantly more likely to require active resuscitation and intensive care, independent of total leucocyte count, gender, degree of prematurity, and diagnosis.

Prominent dyserythropoiesis in four cases of haemophagocytic lymphohistiocytosis

Haemophagocytic lymphohistiocytosis (HLH) is a disease characterised by peripheral blood pancytopenia secondary to haemophagocytosis of formed blood cells by activated histiocytes. The demonstration of haemophagocytosis may be difficult and the diagnosis may require repeated tissue sampling (including bone marrow, cerebrospinal fluid, lymph nodes, spleen, and liver) and the demonstration of associated clinical or laboratory features. This report describes pronounced dyserythropoiesis in the bone marrow aspirates in four patients with HLH, including familial and secondary cases. In three patients, bone marrow haemophagocytosis was inconspicuous or absent, and the prominent dyserythropoiesis may have suggested an alternative diagnosis. The dyserythropoiesis observed should be added to the constellation of clinical and laboratory features associated with HLH.

Donor bone marrow from a sibling with inborn error of metabolism for treatment of acute leukaemia - clinical and biochemical consequences in the non-affected recipient

Bone marrow transplantation (BMT) is increasingly used in an attempt to correct inborn errors of metabolism (IEM). However, little is known about effects of BMT from patients with IEM donating for non-affected recipients. We present data from a 8.5-year-old girl who underwent BMT in second remission for relapsed acute lymphoblastic leukaemia (ALL) at the age of 7 years from her HLA-identical brother who was severely affected by Hunter syndrome (Mucopolysaccharidosis type II, iduronate-2-sulphatase (IDS) deficiency). After BMT not only leukocyte but also plasma activity of IDS was absent. Mixing experiments and immunoadsorption suggest antibody-mediated enzyme inhibition. However, her urinary glycosaminoglycan excretion has not increased post BMT and clinical signs of mucopolysaccharidosis are absent 20 months after BMT. We conclude that patients with white cell enzyme deficiencies and other IEMs do not have to be excluded from bone marrow donation. Antibody production by the graft may occur and be reflected by a marked reduction in plasma enzyme levels but not tissue activity. Similar antibody responses resulting in enzyme inactivation might also affect other enzyme replacement strategies for individuals with IEM.

Failure of allogeneic bone marrow transplantation to correct Diamond-Blackfan anaemia despite haemopoietic stem cell engraftment

We report the case of a 10-year-old boy with congenital pure red cell aplasia (Diamond-Blackfan anaemia) who received an allogeneic bone marrow transplant (BMT) from his HLA-identical sister. The transplant was complicated by moderate veno-occlusive disease (VOD). Despite cytogenetic evidence of complete donor haemopoietic stem cell engraftment there was selective failure of red cell engraftment and he remains red cell transfusion-dependent. This is the first case of a stem cell transplant failing to correct the defect in this condition despite engraftment.

Paroxysmal cold haemoglobinuria of childhood: a review of the management and unusual presenting features of six cases

We report six cases of children presenting with paroxysmal cold haemoglobinuria occurring in a 3-year period in the north-west of England. In all six cases the onset of the illness was dramatic and its duration brief. We note the prominent red cell agglutination was evident in the blood film, the absence of a prompt reticulocyte response and a negative classical direct Donath Landsteiner test in each of these cases. The Direct Coombs Test (DCT) was positive when anticomplement reagents were used but high titres of free autoantibody were not demonstrated in the serum.

Evidence that an HLA-DQA1-DQB1 haplotype influences susceptibility to childhood common acute lymphoblastic leukaemia in boys provides further support for an infection-related aetiology

Comparison of DQA1 and DQB1 alleles in 60 children with common acute lymphoblastic leukaemia (c-ALL) and 78 newborn infant control subjects revealed that male but not female patients had a higher frequency of DQA1*0101/*0104 and DQB1*0501 than appropriate control subjects. The results suggest a male-associated susceptibility haplotype in c-ALL and supports an infectious aetiology.

X linked lymphoproliferative disease in a United Kingdom family

X linked lymphoproliferative disease (XLP; Duncan's disease) is a rare disorder affecting boys and characterised by a defective immune response to Epstein-Barr virus caused by a mutation in a gene located at chromosome Xq25. Three siblings with XLP in a single UK family are reported and the variation in phenotypic expression of the disease in these siblings described. One of the siblings with life threatening fulminant infectious mononucleosis was successfully treated by chemotherapy, followed by bone marrow transplantation using an unaffected brother as the donor. A healthy baby boy recently born into the family was identified as carrying the defective maternal X chromosome using molecular genetic linkage analysis. This family illustrates the extent of present understanding of this often fatal condition.

Seasonal variations in the onset of childhood leukaemia and lymphoma

Infection has long been suspected as a possible factor in the aetiology of leukaemia and lymphoma. If seasonal variation in the onset of disease could be shown in any of the diagnostic subgroups of leukaemia or lymphoma, this would provide supportive evidence of an aetiology linked to exposure to infection. All cases in the Manchester Children's Tumour Registry (aged 0-14 years at diagnosis) with acute lymphoblastic leukaemia (ALL), acute non-lymphocytic leukaemia (ANLL), Hodgkin's disease (HD) or non-Hodgkin lymphoma (NHL) between 1 January 1954 and 31 December 1996 were included in an analysis of seasonal variation in the month of first symptom and the month of diagnosis. Cases of common acute lymphoblastic leukaemia (c-ALL) diagnosed from 1979 onwards were also analysed separately. The groups considered for analysis were: all cases of ALL (n = 1070), ALL diagnosed between 18 and 95 months of age (n = 730), ALL diagnosed over 95 months of age (n = 266), c-ALL (n = 309), ANLL (n = 244), all infant acute leukaemias (ALL and ANLL under 18 months; n = 107), HD (n = 166) and NHL (n = 189). Using the Edwards method, both c-ALL and HD demonstrated significant seasonal variation (P = 0.037 and 0.001 respectively) in date of first symptom, with peaks occurring in November and December respectively. Using this method, no indication of seasonal variation was found in the other diagnostic groups for date of first symptom or in any of the diagnostic groups for date of diagnosis. For comparison with a previous study, a further analysis based on date of diagnosis for all ALL cases, using summer-winter ratios, showed a significant summer excess. These results provide supportive evidence for an infectious aetiology for c-ALL and HD, and possibly for all ALL, which warrants further investigation.

Accelerated telomere shortening in young recipients of allogeneic bone-marrow transplants

BACKGROUND

The establishment of donor-derived haemopoiesis in the recipients of allogeneic bone-marrow transplants (BMT) involves extensive proliferation of haemopoietic stem cells. The biological consequences of this replicative stress are ill defined, but any "ageing" effect would carry the risk of an increased frequency of clonal disorders during later life. We compared blood-cell mean telomere lengths in donor/recipient pairs.

METHODS

Mean telomere length was calculated by in-gel hybridisation to leucocyte DNA from 56 normal individuals aged 0-96 years, and from 14 consecutive BMT recipients (aged 2-14 years) plus their respective donors (aged 2-46 years). Engraftment was confirmed by variable numbers of tandem repeats (VNTR) or gender analysis.

FINDINGS

On average, blood-cell telomeres of transplant recipients were 0.4 kb (95% CI -0.2 to -0.6) shorter than those of their respective donors. This degree of telomere loss is equivalent to a median of 15 years' (range 0-40) ageing in the healthy controls.

INTERPRETATION

The kinetics of haemopoietic engraftment impose replicative stress on the haemopoietic stem cells, resulting in a pronounced ageing effect, which may be sufficient to accelerate the onset of clonal haemopoietic disorders usually associated with later life. Monitoring of haemopoietic status in BMT recipients as time since BMT increases will be important. Assessment of transplant protocols under development in terms of their effects on telomere shortening is also indicated.

Clearance of marrow infiltration after 1 week of therapy for childhood lymphoblastic leukaemia: clinical importance and the effect of daunorubicin. The Medical Research Council's Working Party on Childhood Leukaemia

At the commencement of UKALL XI, a national MRC trial for childhood lymphoblastic leukaemia (ALL), the therapy included a bolus of daunorubicin (DR) on the first 2 d of the protocol. This component of treatment was subsequently withdrawn because of concern about long-term cardiotoxicity. All children both before and after this change of policy had their marrow status at the end of the first week assessed by central review as part of the trial to examine the clinical importance of the rate of disease clearance. This also afforded an opportunity to observe the effect of DR on gross residual disease at an early stage of therapy. 1419 children were studied: 342 received DR ('recipients'), 1077 did not. 44% of the recipients completely cleared their marrow of blast cells after 8 d compared with 13% of the non-recipients (chi2 = 158.2, P < 0.0001). The difference in the proportion with massive residual disease (>80% blasts) was less impressive but there was still a difference in favour of DR recipients (DR 9%, no DR 15%; chi2 = 7.7, P = 0.006). The rate of disease clearance correlated with disease-free survival for both recipients and non-recipients, but there was no significant difference in outcome when comparing the two groups with each other, either in terms of disease-free or relapse-free survival. DR accelerated the rate of blast cell disappearance from the marrow but the difference this made to disease free survival is small or non-existent. It appears to be the relative speed of response to a given therapeutic regimen that is prognostically important rather than the absolute rate of response when comparing one treatment with another.

Hb Sun Prairie: diagnostic pitfalls in thalassemic hemoglobinopathies

We report an Asian Indian family in which two daughters have Hb Sun Prairie, a known unstable alpha 2-globin variant [codon 130, GCT-->CCT; alpha 2 130(H13)Ala-->Pro beta 2]. While the homozygous probands have chronic hemolysis-the same phenotype as previously reported, the heterozygous parents are asymptomatic with a thalassemia carrier phenotype, distinct from the chronic hemolytic state previously described in a heterozygote. Unlike the earlier cases in which family studies were not available, this family clearly exhibits autosomal recessive inheritance, unusual amongst variants within the same region of helix H. Globin chain biosynthesis ratios initially suggested a beta-thalassemic hemoglobinopathy-this was excluded by normal sequence analysis of both beta-globin genes. This case report further illustrates the complexity of phenotypes in the thalassemic hemoglobinopathies. It also demonstrates inversion of the alpha/beta-globin chain biosynthesis ratio, a phenomenon which had been noted in other alpha-globin variants and can be a confounding factor in the investigation of thalassemic hemoglobinopathies.

Oral anticoagulation in paediatric patients: dose requirements and complications

The lack of oral anticoagulant guidelines specific to paediatric practice has led to the adoption of adult regimens, often without scientific evidence of efficacy or safety. A two year prospective study of anticoagulant control was carried out in 45 children aged 9 months to 18 years, the majority of whom were receiving primary prophylactic anticoagulation. The main indication was congenital heart disease, either with (n = 8) or without (n = 34) mechanical valve prosthesis. During a follow up period of 602 patient months the average interval between visits was three weeks. Target international normalised ratios (INRs) were achieved on 62% and 39% of visits for children with low target INR (2.0-3.0) and high target INR (3.0-4.0) respectively. However warfarin dose was altered on only 22% of visits. Warfarin doses required to achieve a stable INR of 2.0-3.0 in 33 children were strongly correlated with weight [dose (mg/d) = 0.07 x weight (kg) + 0.54] but independently influenced by age. No thrombotic complications were recorded, and haemorrhagic events were infrequent (2.1% of visits) and, with one exception, minor. Safe outpatient oral anticoagulation is feasible in children, whose warfarin requirements appear moderately predictable and whose control is no more erratic than that of adults.

Infantile osteopetrosis; bone marrow transplantation from a cousin donor

The successful correction of infantile osteopetrosis in an Asian child by bone marrow transplantation (BMT) from an HLA-A,B matched cousin donor is reported. Retrospective HLA molecular analysis revealed that patient and donor were incompatible for HLA-DPB1. Donor type cells detected in the patient after transplantation indicate successful engraftment. The patient is currently alive and well.

Severe congenital neutropenia unresponsive to G-CSF

Severe congenital neutropenia (SCN) is an inherited disorder characterized by severe neutropenia and recurrent infections from an early age, with bone marrow showing a maturational arrest of granulopoiesis at the promyelocyte stage. Since the introduction of G-CSF therapy the prognosis for affected children has improved dramatically. We describe two patients with SCN who were clinically unresponsive to G-CSF therapy. The results of in-vitro colony assays from these two patients are presented together with the results from the mother of one of these patients who also has a chronic neutropenia, and a further child with SCN who responded to treatment with G-CSF.

Ceftriaxone vs. azlocillin and netilmicin in the treatment of febrile neutropenic children

Efficacy of the cephalosporin, ceftriaxone, was compared with that of the combination of the aminoglycoside, netilmicin, and the penicillin, azlocillin, in the treatment of febrile episodes in immunocompromised neutropenic children undergoing chemotherapy for neoplastic disease. During 100 separate febrile episodes, 40 strains of bacteria were isolated from the blood of 34 patients and a further 55 strains from other sites. Nine strains (four of which were staphylococci) to both netilmicin and azlocillin. There was no difference in clinical response between the two therapeutic regimens as assessed 4 and 7 days after treatment began. Ceftriaxone had the considerable practical advantages of once daily dosage without a need for blood monitoring. Ceftriaxone would appear to be effective as initial monotherapy in the treatment of bacterial infections in severely neutropenic children.

Identification of thiomolybdates in digesta and plasma from sheep after administration of 99Mo-labelled compounds into the rumen

1. At 16 h after the rapid injection of 99Mo-labelled compounds into the rumen of sheep maintained on dried grass (6.2 mg molybdenum/kg dry matter (DM), 4.3 g sulphur/kg DM), labelled thiomolybdates associated with the digesta solids or bound to plasma macromolecular species were displaced from their carriers in vitro and identified by Sephadex G25 chromatography. 2. After molybdate injection, the thiomolybdates displaced from rumen, duodenal and ileal solids were predominantly the trithio- and tetrathio- species. Dithiomolybdate was present to a relatively minor extent. Trace amounts of di- and trithiomolybdates were detected in the liquid phase of digesta from the duodenum. 3. Whether injected into the rumen as molybdate or tetrathiomolybdate, bound 99Mo appearing in plasma was present mainly as di- and trithio- species. The tetrathio- species appeared in trace amounts in plasma only after tetrathiomolybdate injection, despite its existence almost exclusively in this form in rumen digesta. 4. The present study provides direct evidence for thiomolybdate synthesis within the rumen and indicates that while the effects of thiomolybdates in inhibiting copper absorption are likely to be due to tri- and tetrathiomolybdates, post-absorptive effects on Cu metabolism are probably due to di- or trithiomolybdate.