Heather Tapp

Damaging effects of chronic low-dose methotrexate usage on primary bone formation in young rats and potential protective effects of folinic acid supplementary treatment.

Methotrexate (MTX) is a most commonly used anti-metabolite in cancer treatment and as an anti-rheumatic drug. While MTX chemotherapy at a high dose is known to cause bone growth defects in growing bones, effects of its chronic use at a low dose on growing skeleton remain less clear. Here, we examined effects on bone growth of long-term MTX chemotherapy at a low dose in young rats, and potential protective effects of supplementary treatment with antidote folinic acid (given ip at 1 mg/kg 6 h after MTX). After two cycles of 5 once-daily MTX injections (at 0.75 mg/kg, 5 days on/9 days off/5 days on), histological analysis showed that MTX at this dose caused significant reduction in heights of growth plate and primary spongiosa bone on day 22 compared to controls (P<0.05). In contrast, a similar dosing regimen but at a lower dose (0.4 mg/kg) caused only slight or no reduction in heights of both regions. However, after the induction phase at this 0.4 mg/kg dosing, continued use of MTX at a low dose (once weekly at 0.2 mg/kg) caused a reduction in primary spongiosa height and bone volume on weeks 9 and 14, which was associated with an increased osteoclast formation and their bone surface density as well as a decreased osteoblast bone surface density in the primary spongiosa. Folinic acid supplementation was shown able to prevent the MTX effects in the primary spongiosa. These results suggest that acute use of MTX can damage growth plate and primary bone at a high dose, but not at a low dose. However, long-term use of MTX at a low dose can reduce primary bone formation probably due to decreased osteoblastic function but increased osteoclastic formation and function, and supplementary treatment with folinic acid may be potentially useful in protecting bone growth during long-term low-dose MTX chemotherapy.

Genetic susceptibility to viral exposure may increase the risk of cerebral palsy.

Aim: Cytokine polymorphisms may alter the fetal inflammatory response, increasing susceptibility to cerebral palsy (CP). This study investigates associations between selected inflammatory mediator and cytokine gene polymorphisms (Toll‐like receptor‐4 (TLR‐4) Asp299Gly, interleukin‐6 G‐174C and interleukin‐4 C‐589T) and CP from 443 CP infants and 883 control infants. Results were correlated with viral nucleic acids in the same samples.

The prevalence of inherited thrombophilias in a Caucasian Australian population.

Aims: To describe the prevalence of four inherited thrombophilias and their combinations for the first time in a large Caucasian Australian population. Methods: Newborn screening cards of 883 Caucasian babies born in South Australia in 1986–1999 were de‐identified and tested for the following inherited thrombophilic polymorphisms: factor V Leiden (G1691A), prothrombin gene mutation (G20210A), methylenetetrahydrofolate reductase gene (MTHFR) C677T and A1298C, as well as compound heterozygosity for the MTHFR polymorphisms. Results: The birth prevalences of heterozygosity and homozygosity for the four thrombophilic polymorphisms were: factor V Leiden 9.5% and 0.7%, prothrombin gene 4.1% and 0.2%, MTHFR C677T 37.3% and 12.4%, and MTHFR A1298C 38.3% and 11.8%, respectively. Compound heterozygosity for MTHFR C677T and A1298C was seen in 16.6% of the population. Overall, 64.2% and 24.5% of the population studied were homozygous and heterozygous, respectively, for at least one of the four polymorphisms studied. Conclusion: Inherited thrombophilic polymorphisms are common in the Caucasian Australian population. Knowledge of the background prevalence of these polymorphisms will allow further study of their associations in future disease research.

Outcomes of haematopoietic stem cell transplantation for inherited metabolic disorders: a report from the Australian and New Zealand Children's Haematology Oncology Group and the Australasian Bone Marrow Transplant Recipient Registry.

We report a retrospective analysis of 53 haematopoietic stem cell transplants for inherited metabolic disorders performed at ANZCHOG transplant centres between 1992 and 2008. Indications for transplant included Hurler syndrome, ALD, and MLD. The majority of transplants utilized unrelated donor stem cells (66%) with 65% of those being unrelated cord blood. Conditioning therapy was largely myeloablative, with Bu plus another cytotoxic agent used in 89% of recipients. Primary graft failure was rare, occurring in three patients, all of whom remain long‐term survivors following the second transplant. The CI of grade II‐IV and grade III‐IV acute GVHD at day +100 was 39% and 14%, respectively. Chronic GVHD occurred in 17% of recipients. TRM was 12% at day +100 and 19% at one yr post‐transplant. OS at five yr was 78% for the cohort, 73% for patients with ALD and 83% for patients with Hurler syndrome. There was no statistically significant difference in overall survival between unrelated marrow and unrelated cord blood donor groups. The development of interstitial pneumonitis was an independent variable shown to significantly impact on TRM and OS. In summary, we report a large cohort of patients with inherited metabolic disorders with excellent survival post‐allogeneic transplant.

Outcome following unrelated cord blood transplant in 136 patients with malignant and non-malignant diseases: a report from the Australian and New Zealand children''s haematology and oncology group.

Unrelated umbilical cord blood (UCB) is an alternative stem cell source for paediatric patients lacking a matched related or unrelated marrow donor. We report the results of all paediatric unrelated UCB transplants performed in Australia and New Zealand over a 10-year period. A total of 135 patients were transplanted, 100 for malignant disease (74%) and 35 for non-malignant disorders. The majority (88%) of patients received an HLA-mismatched graft. The median infused total nucleated cell dose was 4.7 × 107/kg and CD34+ count 1.9 × 105/kg. Neutrophil engraftment occurred in 83% of patients by day 42 (median 23 days) and platelet engraftment in 55% by day 60 (median 56 days). Grades II–IV and III–IV acute GVHD occurred in 41 and 18% of patients, respectively. TRM and overall survival 1-year post transplant were 32 and 61%, respectively. A higher probability of neutrophil recovery (P=0.004) and faster time to recovery (median 18 days vs 26 days, P=0.008) were observed in recipients of a cord unit with a CD34 cell dose ⩾1.7 × 105/kg. Our results support selection of cord units with CD34 cell doses ⩾1.7 × 105/kg to promote faster engraftment, improve survival and lower TRM.

Two cases of hypereosinophilia and high-risk acute lymphoblastic leukemia.

with normal karyotype. In contrast, AML secondary to chronic MPDs is usually characterized by a poor prognosis. This clinical course is even more remarkable, considering that the patient was over 67 years old when the AML diagnosis was carried out, an age associated with a poor prognostic likelihood. NPMcþ AML is unlikely to have been related to the previous hydroxyurea therapy, as cytoplasmic-mutated NPM is rarely associated with therapy-related AML. Moreover, the leukaemogenic role of hydroxyurea in chronic MPDs remains controversial. In conclusion, we report for the first time on a case of NPMcþ AML developing in a JAK2-V617Fþ PMF. Although no definitive conclusion can be drawn about the cell of origin of AML in our patient, the finding that the blast cells lacked JAK2V617F and displayed all distinctive features of NPMcþ AML suggests that the leukaemic transformation may have occurred de novo in a normal stem cell. Recognition of cases such as the one described in this study is clinically important since AMLs developing in chronic MPDs may be molecularly heterogeneous and their prognoses may vary according to the underlying genetic lesion.

Models of childhood cancer survivorship care in Australia and New Zealand: Strengths and challenges

Childhood cancer survivors remain at risk of developing life‐altering and/or life‐threatening health conditions following the completion of curative treatment. However, no uniform model of care for childhood cancer survivors exists in Australia and New Zealand (ANZ). This study reports on current childhood cancer survivorship care in ANZ, highlighting the challenges childhood cancer survivor long‐term follow‐up (LTFU) clinics face.

Cancer in Australian Aboriginal children: Room for improvement

The study aims to analyse clinical data and outcome in Aboriginal and non‐Aboriginal children with cancer.

Garlic compounds selectively kill childhood pre-B acute lymphoblastic leukemia cells in vitro without reducing T-cell function: Potential therapeutic use in the treatment of ALL.

Drugs used for remission induction therapy for childhood precursor-B acute lymphoblastic leukemia (ALL) are nonselective for malignant cells. Several garlic compounds have been shown to induce apoptosis of cancer cells and to alter lymphocyte function. To investigate the effect of garlic on the apoptosis of ALL cells and lymphocyte immune function, cells from newly diagnosed childhood ALL patients were cultured with several commonly used chemotherapeutic agents and several garlic compounds. Apoptosis, lymphocyte proliferation and T-cell cytokine production were determined using multiparameter flow cytometry. At concentrations of garlic compounds that did not result in significant increases in Annexin V and 7-AAD staining of normal lymphocytes, there was a significant increase in apoptosis of ALL cells with no alteration of T-cell proliferation as determined by CD25/CD69 upregulation or interferonγ, interleukin-2 or tumor necrosis factor-α intracellular cytokine production. In contrast, the presence of chemotherapeutic agents resulted in nonselective increases in both lymphocyte and ALL apoptosis and a decrease in T-cell proliferation and cytokine production. In conclusion, we show selective apoptosis of malignant cells by garlic compounds that do not alter T-cell immune function and indicate the potential therapeutic benefit of garlic compounds in the treatment of childhood ALL.

Differential diagnosis of paediatric bone pain: Acute lymphoblastic leukemia

Nicolien van der Have, Shriram Vaidia Nath, Colin Story, Heather Tapp, C. Nicola, Sarah Moore, Rosemary Sutton and Tamas Revesz