Magnetic resonance imaging screening of cerebral thromboembolic events in children with acute lymphoblastic leukemia: a pilot study.

BACKGROUND: Thromboembolism is a complication of acute lymphoblastic leukemia therapy in children. The majority of thromboembolic events are cerebral thromboses and deep venous thromboses; many asymptomatic deep venous thromboses are detected in children with acute lymphoblastic leukemia by instrumental screening. The aim of this study was to assess the incidence of asymptomatic cerebral thromboembolic events in children with acute lymphoblastic leukemia (ALL) screened by magnetic resonance imaging and magnetic resonance venography. METHODS: 46 children with acute lymphoblastic leukemia, during the induction phase of the AIEOP ALL 2000 protocol, were stratified into 2 groups. In group "A" cerebral thromboembolic events were suspected following the appearance of suggestive signs and symptoms and confirmed by cerebral magnetic resonance imaging and magnetic resonance venography; in group "B" children underwent a screening by cerebral magnetic resonance imaging and magnetic resonance venography, at set times, in absence of symptoms. RESULTS: We observed one cerebral thromboembolic event in both groups; we found no differences between early detecting asymptomatic cerebral thromboembolic events among monitored and not monitored patients. CONCLUSIONS: Our study does not seem to suggest a screening for asymptomatic cerebral thromboembolic events in children with ALL during the induction phase.

Thyroid function and thyroid autoimmunity in childhood acute lymphoblastic leukemia off-therapy patients treated only with chemotherapy.

OBJECTIVE: Scanty data are available about the thyroid function in childhood acute lymphoblastic leukemia (ALL) off-therapy patients treated only with chemotherapy. We aimed to assess the prevalence of thyroid autoimmunity and thyroid dysfunction in such patients. DESIGN: Case-control cross-sectional study. METHODS: Eighty-four patients diagnosed with ALL and treated only with chemotherapy. Mean age at diagnosis 5.9+/-3.6 yr, at recruitment 12.1+/-4.3 yr. The treatment had been stopped 4.3+/-3.2 yr before recruitment. A control group of 60 subjects was recruited. Free T4, TSH, anti-thyroperoxidase, and anti-thyroglobulin antibodies were measured. RESULTS: Anti-thyroglobulin and anti-thyroperoxidase antibodies were negative in all patients. TSH was increased in 7 patients (8.3%) and 3 controls (5.0%). Free T4 was within the normal limits in all patients and controls.Mean TSH and free T4 levels did not statistically differ between controls and ALL offtherapy patients. TSH was negatively correlated with the age at the diagnosis (p=0.01) and the age at the end of therapy (p=0.008). Anti-thyroglobulin and/or anti-thyroperoxidase antibodies were detected in 3 controls (5%; vs study group: p=0.038), 1 of them with increased TSH. CONCLUSIONS: Some patients present hyperthyrotropinemia, without anti-thyroid antibodies, with a prevalence comparable to the control group. The thyroid gland seems more prone to be damaged by chemotherapy at a younger age. We think that a thyroid follow- up in ALL off-therapy patients may be advisable and should be differentiated on the basis of the age at the end of treatment, with more frequent tests for younger patients.

Growth hormone deficiency and antipituitary antibodies in a patient with common variable immunodeficiency.

Common variable immunodeficiency (CVID) is characterized by hypogammaglobulinemia and T-lymphocytes dysfunction. Autoimmune diseases are frequent. A 10.7-yr-old female, diagnosed with CVID when 7 yr old, was referred because of short stature. She was pre-pubertal and short (height -2.86 SD score) with delayed bone age. Her intestinal absorption, routine biochemistry, heart, renal, liver, and thyroid functions were normal. Two stimulation tests for GH showed a maximum peak of 1.9 ng/ml (IGF-1: 154 ng/ml, 147-832). When the patient was 13 yr old (height -4.23 SD score, telarche and pubarche stage 2, bone age 6.25 yr), GH treatment was initiated. Despite poor compliance, the growth velocity showed improvement. Anti-thyrogobulin, anti-thyroperoxidase, anti-21-hydroxylase, and anti-tyrosine-phosphate antibodies were negative while anti- pituitary antibodies (APA) were positive. For the first time, the presence of APA (previously associated with GH deficiency in non-CVID subjects) is reported in a CVID patient. The possibility of an autoimmune involvement of the pituitary gland was previously debated for CVID patients, but had never been demonstrated. This case suggests that in CVID, the pituitary gland can be targeted by autoantibodies and thus a more comprehensive follow-up of these patients should be performed.

Screening for children from families with Rendu-Osler-Weber disease: from geneticist to clinician.

BACKGROUND: Rendu-Osler-Weber syndrome, or hereditary hemorrhagic telangiectasia (HHT), is an autosomal dominant vascular disorder. The syndrome is characterized by telangiectases and arteriovenous malformations (AVMs) affecting skin, mucosae and internal organs. AVMs often remain clinically silent until provoking sudden serious complications, responsible for important morbidity and mortality which can occur both in adulthood and in children. The incidence of AVMs in HHT pediatric populations is unknown. OBJECTIVE: To describe the screening protocol performed in the first genotypically confirmed HHT pediatric population and to estimate the incidence of occult brain, lung and liver AVMs and the different disease phenotypes. MATERIALS AND METHODS: Molecular analysis was performed on 35 children, both symptomatic and asymptomatic, who were family members of probands with a previously identified mutation. Clinical-instrumental examination was performed on the mutation positive cases. Nasal telangiectases were investigated by anterior rhinoscopy. Contrast echocardiography and high resolution thoracic multislice computed tomography (CT) were performed to detect pulmonary arteriovenous malformations (PAVMs), and echo-color Doppler, and abdominal CT to detect hepatic arteriovenous malformations (HAVMs). Brain magnetic resonance imaging was utilized to detect cerebral angiopathic involvement. RESULTS: Molecular analysis demonstrated the mutation-carrier status in 22/35 children. Nineteen children, 12 of whom had epistaxis, positive to molecular testing underwent clinical evaluation. Nasal teleangiectases were found in 68%, mucocutaneous telangiectases (fingers, lips and oral cavity) in 79%, PAVMs in 53%, HAVMs in 47% and cerebral anteriovenous malformations and/or cerebral ischemic changes secondary to PAVMs in 12%. CONCLUSIONS: We evidenced a high incidence of HHT children with occult visceral lesions suggesting that a diagnostic screening may be indicated to appropriately treat brain and lung malformations.

HHT in childhood: screening for special patients.

Hereditary hemorrhagic telangiectasia (HHT) or the Rendu-Osler-Weber disease is a systemic fibrovascular autosomal dominant dysplasia, recognised when three of the following four clinical manifestations are present, according to the proposal of Shovlin.: recurrent nosebleeds, lelangiectasias of the skin, visceral lesions, and positive family history. HHT is often difficult to diagnose on the basis of history and physical examination alone, especially in infants and children. The signs and symptoms of HHT are nonspecific and are extremely variable within families. Given the frequent occurrence of clinically silent lesions in lung and brain arteriovenous malformations which can result in morbidity or death, much consideration should be given to screening patients with HHT for asymptomatic fistulae and to their treating once they are discovered. Presymptomatic interventions in such cases may substantially affect the outcome. It may be possible to state that lesions of HHT arise early in life, but do not reach sufficient size to cause symptoms until the second decade. Furthermore, as clinical manifestations often occur later in life, the development and the implementation of a molecular diagnosis will allow the identification of subjects with no evident signs of the disease but carrying the familial mutation. This is fundamental in order to establish reliable screening protocols for the prevention and cure of the disease and, to determine the presence of family members with no disease-associated mutation, who do not require further clinical screening.

Management of liver disease in thalassemia: main drug targets for a correct therapy.

Liver disease is the second cause of mortality in thalassemia major. We present a review on the hepatic damage in thalassemic patients aimed at a knowledge of current preventive, diagnostic and therapeutic approaches, useful to guide in clinical judgment and treatment decisions. Transfusion related iron overload and hepatitis are the causes of liver damage in thalassemic patients. We examined means of primary prevention, anti-hepatitis vaccinations, blood donors screening; diagnostic tests for secondary prevention (computed tomography, magnetic resonance imaging, super conducting quantum interference device and biopsy) were also discussed about. A survey of treatment methods and strategies ( chelation therapy, antiviral treatments and liver and bone marrow transplantation) follows.

[Nasopharyngeal colonization of Streptococcus pneumoniae in healthy children: percentage of carriers, serotypes distribution and antibiotic resistance]. / Colonizzazione nasofaringea di Streptococcus pneumoniae in bambini sani: percentuale di portatori, distribuzione dei sierotipi e antibiotico-resistenza.

AIM: The nasopharyngeal carriage of Streptococcus pneumoniae is an important risk factor for pneumococcal diseases. Data regarding prevalence and serotype distribution of this pathogen are lacking in our population. EXPERIMENTAL DESIGN: longitudinal observational cohort study. SETTING: healthy children aged 1-7 years attending day-care centers and schools of a district of a Southern Italy city. MEASURES: the nasopharyngeal colonization rate of Streptococcus pneumoniae as well as its antibiotic susceptibility was determined. RESULTS: Of 317 nasopharyngeal cultures obtained, 18.29% of the cultures were positive for Streptococcus pneumoniae; 60.34% of the isolates were serotypes 19A, 19F, 14, 6B, or 23F; 8.62% of the strains were intermediately resistant to penicillin. Erythromycin-resistance was observed in 65.51% of the micro-organisms isolated and particularly serotypes 19, 14, and 6 were more erythromycin-resistant than organisms of other serotypes. Co-trimoxazole resistance was detected in 17.24% of the strains. All the strains resulted uniformly susceptible to cefotaxime and ceftriaxone. CONCLUSION: The high rate of nasopharyngeal carriage of Streptococcus pneumoniae, along with the resistance to antibiotics widely used in the community, suggests the importance of an epidemiological surveillance as well as the application of new vaccine strategies.

Streptococcus pneumoniae nasopharyngeal colonization in young healthy children: rate of carriage, serotype distribution, and antibiotic resistance.

The nasopharyngeal colonization rate of Streptococcus pneumoniae and its antibiotic susceptibility was determined in a given population of 317 young children (ages 1-7 years) in the area of Bari, Italy. 18.29% of the cultures were positive for S. pneumoniae. 8.62% of the strains were intermediately resistant to penicillin. Erythromycin-(65.51%) and cotrimoxazole-(17.24%) resistance was also observed whereas all the strains resulted uniformely susceptible to cefotaxime and ceftriaxone. The high rate of nasopharyngeal carriage of Streptococcus pneumoniae along with the resistance to antibiotics widely used in the community suggests the importance of epidemiological surveillance as well as the application of new vaccine strategies.

Bone marrow transplantation in a case of severe, type II congenital dyserythropoietic anaemia (CDA II).

Type II congenital dyserythropoietic anaemia (CDA-II or HEMPAS) is an autosomal recessive disorder, representing the most frequent form of congenital dyserythropoiesis. It is characterised by normocytic anaemia, variable jaundice and hepato-splenomegaly. Gallbladder disease and secondary haemochromatosis are frequent complications. We report a case characterised by severe transfusion-dependent anaemia. The proband inherited CDA-II in association with beta-thalassaemia trait. Splenectomy did not abolish the transfusion dependence and this, in association with poor compliance to iron-chelation therapy, prompted us to consider bone marrow transplantation (BMT) from his HLA-identical sibling. The preparative regimen included busulfan, thiotepa and fludarabine, and graft-versus-host disease prophylaxis consisted of cyclosporin A and short-term methotrexate. Engraftment of donor cells was prompt and the post-transplant course uncomplicated. The patient is alive and transfusion-independent 36 months after allograft. This is the first case of severe CDA-II to undergo BMT. Analysis of this pedigree suggests that interaction with beta-thalassaemia enhanced the clinical severity of CDA-II, making BMT an attractive therapy for patients with transfusion dependence.

Defective surface expression of attractin on T cells in patients with common variable immunodeficiency (CVID).

The proliferative responses of T lymphocytes of a subset of patients with CVID are abnormally low. This may be due to abnormalities in extracellular interactions or signalling defects downstream from membrane-associated receptors. Demonstrating that the T cell receptor signalling was normal, we observed no abnormal pattern of activation-induced tyrosine phosphorylation in cells from CVID patients. Moreover, the addition of exogenous IL-2 increased the low proliferation to mitogens, thus indicating the integrity of the IL-2R signalling apparatus. Attractin is a rapidly expressed T cell activation antigen involved in forming an association between T cells and monocytes. Twenty-four to 48 h after activation by CD3 cross-linking, attractin expression was not up-regulated on the cells of CVID patients despite normal up-regulation of CD25 and CD26. On control cells, however, attractin expression was up-regulated together with CD25 and CD26. The addition of the purified 175-kD attractin was capable of restoring the proliferative response of peripheral blood mononuclear cells following CD3 X-L in the presence of suboptimal concentrations of rIL-2 (10 and 20 U/ml). The effect was dose-dependent with the maximal effect at a concentration of 500 ng/ml, and present at a concentration as low as 50 ng/ml. Due to the likely role of attractin in cell guidance and amplification of the immune response, our results indicate that the lack of up-regulation of the molecule in patients with CVID may in turn affect any further step of productive immune response. Our finding may also imply a potential therapeutic role for this novel molecule.

Thrombin generation in children with acute lymphoblastic leukemia: effect of leukemia immunophenotypic subgroups.

Elevated plasma concentrations of endogenous thrombin generation markers and thrombotic events have been reported in children with leukemia. The aim of this study was to evaluate the effects of cancer and its treatment on thrombin generation (TAT levels) in children with acute lymphoblastic leukemia (ALL). The authors evaluated 32 children (23 M, 9 F) aged between 1 and 15 years (mean 6) affected by ALL (immunophenotypic subgroups: 16 common, 7 T, and 9 pre-B type). In all patients TAT levels at onset and after 5-6 doses of L-asparaginase were evaluated. TAT levels were higher in patients both at onset (13.04 +/- 10.90 ng/L) and after the 5-6 doses of L-asp (19.41 +/- 11.05 ng/L) with respect to controls (4 +/- 1 ng/L) (p < .001 and p < .001). TAT levels after 5-6 doses of L-asp were higher than those at onset (p < .001). Factorial ANOVA showed that at onset there was a significant effect of leukemia immunophenotypic subgroups upon TAT levels (p < .05) and no effect of inherited thrombotic risk factors. These results indicate that in children with ALL an important role is played by acquired thrombotic risk factors, among which the indirect cancer procoagulant activity has its importance.

Development of autologous T lymphocytes in two males with X-linked severe combined immune deficiency: molecular and cellular characterization.

We report on two patients affected with severe combined immune deficiency (SCID) with an unusual immunological phenotype and a substantial number of autologous, poorly functioning T cells. Distinct mutations identified at the IL2RG locus in the two patients impaired IL-2-mediated signaling but affected T-cell lymphopoiesis differently, resulting in generation of a polyclonal or oligoclonal T-cell repertoire. These observations add to the growing complexity of the immunological spectrum of SCID in humans and indicate the need for detailed immunological and molecular investigations in atypical cases.

Acute childhood idiopathic thrombocytopenic purpura: AIEOP consensus guidelines for diagnosis and treatment. Associazione Italiana di Ematologia e Oncologia Pediatrica.

BACKGROUND AND OBJECTIVE: A recent evaluation carried out by the Associazione Italiana di Ematologia e Oncologia Pediatrica (AIEOP) about practice management of acute childhood idiopathic thrombocytopenic purpura (ITP) revealed a remarkable difference of behaviors among the different AIEOP centers. A need for common practice guidelines for this frequent illness arose from this observation. Our aim was to make the diagnosis and treatment of childhood ITP uniform. In the future we will evaluate the influence of these guidelines on practice behaviors. DATA SOURCES AND METHODS: Our main reference was the 1996 document produced by the American Society of Hematology (ASH). Their recommendations were updated with information from literature searched for in the MEDLINE database (June 1996-October 1998); search terms included: thrombocytopenia, ITP, diagnosis, therapy, children. The computerized search retrieved 83 articles. DATA EXTRACTION: the scientific validity of the literature was evaluated by a panel of members using published guidelines. The strength of the evidence was assessed using level of evidence criteria. Only data from level I and level II studies were taken in account. Only one study out of the 83 retrieved articles met these selection criteria and it was considered in addition to the 11 out of 581 articles selected in the ASH ITP guidelines. This preliminary work pointed out each issue about ITP not addressed by clinical studies and all participants in a Consensus Conference expressed their opinion about these issues. RESULTS: Diagnosis is essentially based on history, physical examination, a complete blood count and an examination of the peripheral blood smear. Treatment is recommended taking into account the clinical picture and number of platelets. The main difference between these guidelines and those from ASH are: AIEOP guidelines rely on the opinion of the members of the consensus conference, ASH ones on a panel of experts; therapeutic options include only products available in Italy; the indications to treatment rely more on clinical picture than on platelet number. INTERPRETATION AND CONCLUSIONS: These are explicitly developed, evidence-based practice guidelines to assist Italian pediatricians in making decisions about diagnosis and appropriate health care for patients with acute childhood ITP.

Malignancy: X-Linked Cytochrome B Positive Chronic Granulomatous Disease treated by Bone Marrow Transplantation.

Chronic granulomatous disease is caused by a genetic defect in the oxidase of phagocytic cells which results in increased susceptibility to recurrent infections. Conventional treatment includes the use of antimicrobials and interpheron-gamma. This study was performed to assess the clinical efficacy of allogeneic bone marrow transplantation in definitively correcting the functional underlying defect of chronic granulomatous disease. An 8-year-old boy with a rare type X-linked cytochrome b positive chronic granulomatous disease underwent allogeneic bone marrow transplantation after conditioning with busulfan and cyclophosphamide. The patient's HLA identical sister was marrow donor. The post-transplant outcome was uneventful. During the 9 year follow-up period the patient has been constantly free of infections, maintained an excellent clinical performance with full correction of the granulocyte functional defect. This case confirms that allogeneic bone marrow transplantation is the only treatment capable to cure chronic granulomatous disease to those patients who cannot be optimally treated with conventional therapy.

Mutational screening of thrombopoietin receptor gene (c-mpl) in patients with congenital thrombocytopenia and absent radii (TAR).

Thrombocytopenia with absent radii (TAR) is a rare autosomal recessive disease characterized by hypomegakaryocytic thrombocytopenia and bilateral radial aplasia. We performed mutational screening of coding and promoter regions of the c-mpl gene, encoding thrombopoietin (TPO) receptor, by sequence analysis in four unrelated patients affected by TAR syndrome. Our results indicate that c-mpl gene mutations are not a common cause of thrombocytopenia in TAR syndrome.

Lupus anticoagulant, anticardiolipin antibodies and hepatitis C virus infection in thalassaemia.

Anticardiolipin antibodies (ACA) and lupus anticoagulant (LA) have been detected in patients with hepatitis C virus (HCV) infection and have been associated in autoimmune diseases (i.e. systemic lupus erythematosus) with an increased risk of thromboembolic events. Because of the high prevalence of HCV infection and the thrombotic risk described in thalassaemia we decided to investigate the prevalence of ACA and LA in a cohort of 68 thalassaemia patients. We found a high prevalence (34%) of beta2-glycoprotein I independent ACA in our thalassaemia patients which was related to HCV infection. None of patients developed any complications related to antiphospholipid antibodies (APL); therefore the clinical significance of positivity for APL in patients with HCV infection is at present unclear. In conclusion, the results of our study indicate that ACA in the serum of HCV-infected thalassaemic patients exhibit the characteristics of natural autoantibodies rather than those of the pathogenic autoantibodies that are found in patients with systemic lupus erythematosus.

Resistance to activated protein C in thalassaemic patients: an underlying cause of thrombosis.

We evaluated 81 thalassaemia major and 4 thalassaemia intermedia patients (48 M, 37 F), median age 17 years; 62/85 patients were HCV-positive, 3/85 HIV-positive, 19/85 were splenectomized. Forty normal healthy children were recruited as the control group. The number of thrombotic events was studied retrospectively. Platelet poor plasma was filtered and quick-frozen at -70 degrees C until time of assay. APC resistance was measured in an activated thromboplastin time and results were expressed as normalized ratio. All tests were done with diluted 1 in 5 (v/v) factor V deficient plasma and with undiluted plasma. Molecular genetic investigation of factor V gene was performed with polymerase chain reaction, followed by digestion of amplified products with restriction enzyme Mnl I. Data obtained with molecular investigation revealed the presence of 4 heterozygous subjects for factor V Leiden (4.7%). Functional tests were able to detect all heterozygotes for factor V Leiden both with undiluted and with diluted plasma, and there were no false negative subjects. However, undiluted plasma revealed a greater number of false positive subjects (n=15) than did diluted plasma. Therefore, tests done with undiluted and diluted plasma revealed a 100% sensitivity, while specificity was 81% for undiluted plasma and 97% for diluted plasma. Only one thrombotic event was observed in one of the 85 studied patients, as a case of stroke in a thalassaemia intermedia patient with APC resistance. In the same patient an additional thrombogenic risk factor was represented by a pronounced haematocrit increase at the beginning of her transfusion regimen.

Thromboembolic events in beta thalassemia major: an Italian multicenter study.

Thromboembolic (TE) events have been frequently reported in beta-thalassemic patients in association with known risk factors such as diabetes, complex cardiopulmonary abnormalities, hypothyroidism, liver function anomalies, and postsplenectomy thrombocytosis. In a recent survey involving 9 Italian thalassemic centers, we identified 32 patients with TE episodes in a total of 735 subjects, of whom 683 had thalassemia major and 52 thalassemia intermedia, corresponding to 3.95 and 9.61%, respectively. There was a great variation in localization: the main one (16/32) was CNS, with a clinical picture of headache, seizures and hemiparesis. Other localizations were the pulmonary (3 patients), mesenteric (1 patient) and portal (2 patients) sites. There were 6 cases of deep venous thrombosis (2 in the upper limbs, 4 in the lower ones). Intracardiac thrombosis was found in 2 subjects and clinical and laboratory signs of DIC were observed in 2 others during pregnancy. Since our patients with TE events present a statistically significantly higher incidence of associated dysfunction (cardiomyopathy, diabetes, liver function anomalies, hypothyroidism) than those without TE events (50 vs. 13.8%), we suggest close monitoring of those patients who are at higher risk of developing TE events because of the presence of one or more of these predisposing factors.