Valentina Coletti

CD1d expression on B-precursor acute lymphoblastic leukemia subsets with poor prognosis.

Acute lymphoblastic leukemia (ALL) is the most frequent malignancy of childhood. Although therapeutical advances have been achieved, some ALL subgroups still fare poorly. CD1d is a monomorphic molecule that provides a suitable target for immunotherapy in view of the characterization of a glycolipid, α-galactosylceramide (α-GalCer), capable of being presented to CD1d-restricted T cells with cytotoxic potential. We investigated CD1d expression in 80 pediatric B-cell precursor (BCP) ALL cases defined according to immunophenotype, cytogenetic features and age at onset. CD1d was detected on ALL cells in 15% of the patients. CD1d+ ALLs were significantly associated with infant leukemia, pro-B phenotype and mixed-lineage leukemia (MLL)/AF4 gene rearrangement. Accordingly, overall survival of patients with CD1d+ ALL was significantly shorter. CD1d+ leukemic blasts were able to present α-GalCer via CD1d to cytotoxic CD1d-restricted T cells, which induced apoptosis of ALL cells that was inhibited by mAb to CD1d. CD1d+ blasts loaded with α-GalCer elicited cytokine secretion by CD1d-restricted T cells. Analysis of bone marrow (BM) cells derived from normal donors revealed that CD19+/CD1d+ cells were mostly mature B lymphocytes. However, a minority of BCPs expressed CD1d. Thus, expression of CD1d in ALL cases heralds an adverse prognosis but may provide a therapeutic tool.

The combination of bortezomib with chemotherapy to treat relapsed/refractory acute lymphoblastic leukaemia of childhood

Achieving complete remission (CR) in childhood relapsed/refractory acute lymphoblastic leukaemia (ALL) is a difficult task. Bortezomib, a proteasome inhibitor, has in vitro activity against ALL blasts. A phase I‐II trial, reported by the Therapeutic Advances in Childhood Leukaemia and Lymphoma (TACL) consortium, demonstrated that bortezomib with chemotherapy has acceptable toxicity and remarkable activity in patients with relapsed ALL failing 2–3 previous regimens. We evaluated bortezomib in combination with chemotherapy in 30 and 7 children with B‐cell precursor (BCP) and T‐cell ALL, respectively. Bortezomib (1·3 mg/m2/dose) was administered intravenously on days 1, 4, 8, and 11. Chemotherapy agents were the same as those used in the TACL trial, consisting of dexamethasone, doxorubicin, vincristine and pegylated asparaginase. Three patients (8·1%) died due to infections. Twenty‐seven patients (72·9%) achieved CR or CR with incomplete platelet recovery (CRp). Fourteen had minimal residual disease (MRD) lower than 0·1%. Twenty‐two of 30 BCP‐ALL patients (73·3%) and 5/7 patients (71%) with T‐cell ALL achieved CR/CRp. The 2‐year overall survival (OS) is 31·3%; CR/CRp patients with an MRD response had a remarkable 2‐year OS of 68·4%. These data confirm that the combination of bortezomib with chemotherapy is a suitable/effective option for childhood relapsed/refractory ALL.

Acute thiamine deficiency and refeeding syndrome: Similar findings but different pathogenesis

OBJECTIVE Refeeding syndrome can occur in several contexts of relative malnutrition in which an overaggressive nutritional support is started. The consequences are life threatening with multiorgan impairment, and severe electrolyte imbalances. During refeeding, glucose-involved insulin secretion causes abrupt reverse of lipolysis and a switch from catabolism to anabolism. This creates a sudden cellular demand for electrolytes (phosphate, potassium, and magnesium) necessary for synthesis of adenosine triphosphate, glucose transport, and other synthesis reactions, resulting in decreased serum levels. Laboratory findings and multiorgan impairment similar to refeeding syndrome also are observed in acute thiamine deficiency. The aim of this study was to determine whether thiamine deficiency was responsible for the electrolyte imbalance caused by tubular electrolyte losses. METHODS We describe two patients with leukemia who developed acute thiamine deficiency with an electrolyte pattern suggestive of refeeding syndrome, severe lactic acidosis, and evidence of proximal renal tubular dysfunction. RESULTS A single thiamine administration led to rapid resolution of the tubular dysfunction and normalization of acidosis and electrolyte imbalance. This demonstrated that thiamine deficiency was responsible for the electrolyte imbalance, caused by tubular electrolyte losses. CONCLUSIONS Our study indicates that, despite sharing many laboratory similarities, refeeding syndrome and acute thiamine deficiency should be viewed as separate entities in which the electrolyte abnormalities reported in cases of refeeding syndrome with thiamine deficiency and refractory lactic acidosis may be due to renal tubular losses instead of a shifting from extracellular to intracellular compartments. In oncologic and malnourished patients, individuals at particular risk for developing refeeding syndrome, in the presence of these biochemical abnormalities, acute thiamine deficiency should be suspected and treated because it promptly responds to thiamine administration.

Infant leukaemia: Clinical, biological and therapeutic advances

UNLABELLED Infant acute lymphoid leukaemia (IALL) represents a distinct subset with an extremely poor response to therapy, despite major progress in the treatment of childhood leukaemia. However, several studies have shown that, even in this generally considered homogeneous group, a distinction could be made with regard to prognosis. The outcome of IALL patients with ALL-1/MLL rearrangements at the 11q23 cytogenetic band, early pre-B immunophenotype, high WBC count and age below 6 mo is significantly worse than in patients without these characteristics, and current therapies appear inadequate in a significant number of cases. Therefore, an international protocol (Interfant 99) was recently started, using a more aggressive approach, which included lymphoid- and myeloid-specific drugs, and indications for stem-cell transplantation. We reviewed the clinical characteristics of the disease, the results of several recent international clinical trials, and our experience with 16 infants with acute lymphoid leukaemia diagnosed and treated at our institution. CONCLUSION It is extremely important to stratify patients for prognosis, taking into account clinical and biological variables with independent prognostic value. The aim is to select more adequate, risk-adapted, therapeutic strategies which also consider related or unrelated bone marrow transplant consolidation for patients with very poor prognosis.

Idiopathic thrombocytopenic purpura (ITP) in children

Idiopathic thrombocytopenic purpura in children remits spontaneously in the majority of cases but most children require treatment. Between 1995 and 2005, 265 children (0–15 years old) have been consecutively observed and treated: 28 children with high doses of methylprednisolone (HDMP) (15 mg/kg × 4 days), 63 with HDMP (7.5 mg/kg × 4 days), 37 with HD dexamethasone (DXM) pulses, 29 with low doses of MP, and 51 with different doses of intravenous immunoglobulins (IVIG) (0.4 or 0.8 g/kg). Fifty‐seven children have not been treated because of a platelet count ≥10 × 109/L and no significant bleeding. Two hundred forty‐four (92.1%) children reached a persistent CR, 237 (89.4%) after a first‐line treatment or the wait and see strategy. No statistically significant differences in CR related to different treatments have been observed. IVIG and HDMP (7.5 mg/kg for 4 days) are the best treatments to reach quickly safe platelet levels ≥30 × 109/L (3–6 days) and CR (7–11 days). Among non‐responding (NR) patients, seven have been splenectomized and three reached stable CR. These results emphasize differences with adult ITP. Pediatr Blood Cancer 2006;47:665–667.

Infant leukaemia: Clinical, biological and therapeutic advances: Advances in infant leukaemia

Infant acute lymphoid leukaemia (IALL) represents a distinct subset with an extremely poor response to therapy, despite major progress in the treatment of childhood leukaemia. However, several studies have shown that, even in this generally considered homogeneous group, a distinction could be made with regard to prognosis. The outcome of IALL patients with ALL‐1/MLL rearrangements at the 11q23 cytogenetic band, early pre‐B immunophenotype, high WBC count and age below 6 mo is significantly worse than in patients without these characteristics, and current therapies appear inadequate in a significant number of cases. Therefore, an international protocol (Interfant 99) was recently started, using a more aggressive approach, which included lymphoid‐ and myeloid‐specific drugs, and indications for stem‐cell transplantation. We reviewed the clinical characteristics of the disease, the results of several recent international clinical trials, and our experience with 16 infants with acute lymphoid leukaemia diagnosed and treated at our institution.

Sometimes it is better to wait: First Italian case of a newborn with transient abnormal myelopoiesis and a favorable prognosis

Congenital leukemia is rare disease with an incidence of one to five cases per million births. Transient abnormal myelopoiesis (TAM), also called transient myeloproliferative disorder, is a pre-leukemia disorder that may occur in Down syndrome (DS) or non-DS infants. TAM may enter spontaneous remission; however, continual monitoring is required, as this disorder has been observed to develop into acute megakaryoblastic leukemia in 16–30% of cases. In the literature, 16 cases of TAM in non-DS infants have been reported. The case presented in the current study is, to the best of our knowledge, the first case of an Italian non-DS newborn presenting with clinical manifestations of acute leukemia at five days after birth, exhibiting a normal karyotype, trisomy 21 only in blast cells, and spontaneous remission. Chromosomal analyses on peripheral blood cells, bone marrow cells and dermal fibroblasts were conducted using a G-banding technique, and fluorescence in situ hybridization (FISH) was used to identify the critical regions of DS. Amplification of GATA binding protein 1 (GATA1) exon 2 genomic DNA was performed using polymerase chain reaction. Cytogenetic analysis of 50 peripheral blood cells and dermal fibroblasts from the patient revealed a normal karyotype: 46, XX. Conversely, cytogenetic analysis of the patients bone marrow revealed an abnormal karyotype 47, XX+21. In order to investigate this result, FISH was performed, which identified the presence of three signals in 70% of the cells and two signals in 30% of bone marrow cells. GATA1 sequencing revealed the substitution of a single base (c.150delG) in exon 2. Seven months after the initial analysis, FISH and cytogenetic analyses of the stimulated/unstimulated peripheral blood cells and bone marrow cells were performed, revealing that each exhibited diploid signals, as observed in a normal karyotype.

Supplementation of fibrinogen concentrate in children with severe acquired hypofibrinogenaemia during chemotherapy for acute lymphoblastic leukaemia: our experience

Dear Sir, Bleeding and thrombosis are not infrequent problems in children receiving treatment for acute lymphoblastic leukaemia (ALL); these serious complications are associated with the administration of asparaginase, which induces depletion of antithrombin and fibrinogen. Thrombotic complications often make necessary to suspend asparaginase with possible effects on the child’s outcome. Thrombocytopenia and low fibrinogen levels increase the risk of bleeding and haemorrhagic complications of ALL therapy and, in particular, of mini-invasive procedures (lumbar puncture, bone marrow aspirate and biopsy, etc.). Prophylactic supplementation of plasma and plasma-derived coagulation products remains controversial in these patients; recommendations for prevention and management are lacking due to a weak evidence base, resulting in considerable variation in practice1,2. Hypofibrinogenaemia is defined by a decreased level of fibrinogen between 0.5 g/L and the lower limit of the normal range for the local laboratory (usually 1.5 g/L); severe hypofibrinogenaemia (fibrinogen <0.5 mg/L) is generally corrected by the administration of fresh frozen plasma (FFP) or cryoprecipitate3. FFP contains other coagulation factors that may increase the risk of thrombosis and has several limitations including a low fibrinogen content, which means that large volumes must be given, and the risk of transfusion-related complications (e.g., transfusion-related acute lung injury [TRALI])3,4. The depletion of asparagine, obtained by administration of asparaginase, represents one of the cornerstones of antineoplastic chemotherapy of ALL; as FFP contains asparagine, we could speculate that administration of FFP may partly antagonize the effects of chemotherapy with asparaginase5. Cryoprecipitate contains a higher concentration of fibrinogen than FFP, but the amount is variable and cannot be determined accurately; moreover cryoprecipitate includes factor VIII and von Willebrand factor, which could increase the risk of thrombosis3. Furthermore we must keep in mind the possible risk of viral transmission that accompanies the use of FFP and cryoprecipitate3. Supplementary fibrinogen can also be provided by fibrinogen concentrate, as an alternative to FFP and cryoprecipitate. Fibrinogen concentrate is produced from pooled human plasma, pasteurised, purified and lyophilised; it is subjected to viral inactivation procedures that minimise the risk of transmission of viral agents and its concentration is standardised4. Fibrinogen replacement therapy is currently indicated as prophylaxis and therapy of haemorrhage in congenital and acquired fibrinogen deficiency3,4. Fibrinogen concentrate is now the predominant therapeutic option for the prophylaxis and treatment of bleeding in patients with congenital afibrinogenaemia and in secondary prophylaxis in patients with life-threatening bleeding and a high risk of recurrence (e.g. intracranial haemorrhage); several studies have documented its efficacy and its successful administration as prophylaxis and therapy in cases of acquired hypofibrinogenaemia (loss or dilution coagulopathy, trauma, cardiac and thoracic surgery, obstetric haemorrhage, liver failure, disseminated intravascular coagulation)3,4. No Author has so far reported the administration of fibrinogen concentrate for the correction of acquired hypofibrinogenaemia in children with ALL during chemotherapy. Haemocomplettan (CSL Behring, Marburg, Germany) is a human pasteurised, highly purified, plasma-derived fibrinogen concentrate, and a number of studies have evaluated the effects of fibrinogen supplementation with this agent in patients suffering from various forms of congenital or acquired hypofibrinogenaemia3. We administered fibrinogen concentrate (Haemocomplettan) to seven children (median age 10 years; minimum 2 maximum 15; males 4, females 3) during chemotherapy for ALL; they were enrolled in the AIEOP ALL 2000 and AIEOP-BFM ALL 2009 protocols. Patients were treated with PEG-asparaginase (5/7), E. coli asparaginase (1/7), and Erwinase (1/7). They presented with severe acquired hypofibrinogenaemia (fibrinogen <0.5 mg/L; median 0.43 mg/L; minimum 0.18, maximum 0.5), secondary to asparaginase administration, during the induction phase of chemotherapy. Five of the seven patients had a prolonged prothrombin time; none of the patients showed clinical signs of coagulopathy but presented with thrombocytopenia so we considered them at high risk of bleeding and decided to administer replacement therapy with fibrinogen concentrate. The median dose of fibrinogen concentrate given was 35 (minimum 20, maximum 70) mg/kg/daily for 1 day (4/7 patients) or 2 days (3 patients). Levels of fibrinogen higher than 0.7 mg/L were achieved in five of the seven patients and prothrombin time normalised in three of five patients just after the first administration of fibrinogen concentrate (the characteristics of the patients and results are summarised in Table I). Prothrombin time was not normalised and fibrinogen levels remained below 0.7 mg/L in two patients who had received the lowest dose of fibrinogen concentrate (20 mg/kg/daily, 1 patient for 1 day, 1 patient for 2 days); one of these patients needed FFP. No patients showed bleeding or experienced thromboembolic complications following the replacement of fibrinogen with fibrinogen concentrate. Although our experience is limited, supplementation with fibrinogen concentrate at adequate dosages in children with acquired hypofibrinogenaemia and altered haemostatic balance secondary to asparaginase, seems to be safe and useful in normalising the levels of fibrinogen and prothrombin time. Table I Characteristics of the patients treated with fibrinogen concentrate. The management of altered haemostatic balance in children receiving asparaginase for ALL is strongly debated; in the event that you decide to treat the haemostatic derangement, we think it would be advisable to correct the severe impairments of individual factors, i.e. fibrinogen and antithrombin. The severe hypofibrinogenaemia could be corrected by supplementation with fibrinogen concentrate rather than FFP or cryoprecipitate. The administration of fibrinogen concentrate in place of FFP or cryoprecipitate, at an adequate dosage and in selected cases, could reduce the risk of giving other clotting factors that may be prothrombotic and it could reduce the risk of transmission of viral infection. In addition the use of fibrinogen concentrate as an alternative to FFP would avoid both the risk of TRALI and especially the exposure of the patient to a source of asparagine which could counteract the antineoplastic action of asparaginase. Obviously, our observations need to be confirmed by additional clinical trials focusing on the management of altered haemostatic balance in children with ALL and on the dosing, efficacy and safety of the fibrinogen concentrate.