Monoclonal gammopathy of undetermined significance in pediatric kidney transplant: a possible role of Epstein-Barr virus.

MG is a common event of hematologic malignancies. There are many papers regarding kidney transplantation patients with MGUS in adults, while data in pediatrics are scarce. The etiology and clinical significance of MGUS are unclear both in adults and children. Immunosuppressive drugs, graft antigenicity, and viral infection could play a possible role. The viruses most frequently implicated seem to be EBV or CMV in particular, but their role has to be defined better. However, many investigators have emphasized an impaired balance between an adequate immune response and reactivation of viral infection.

Antibiotic prophylaxis in children with cancer or who have undergone hematopoietic cell transplantation.

Bacterial infections are common in children with cancer and can lead to life-threatening complications. Infections in these patients mainly occur during neutropenic periods, and may be caused by Gram-positive or Gram-negative bacteria. The patients at highest risk of serious infections include those with acute lymphoblastic leukemia (ALL) or acute myeloid leukemia (AML), and those undergoing myeloablative hematopoietic cell transplantation (HCT). This is a review with the main aim of making a critical appraisal of the literature, and summarising what is currently known and can be recommended. The most significant studies support the use of floroquinolones (mainly ciprofloxacin) as the most rational approach to treat pediatric patients with probably long-lasting neutropenia, although trimetoprim-sulphametoxazole and amoxicillin/clavulanate may theoretically be valid alternatives. No prophylaxis seems to be needed for children with cancer without severe neutropenia. However, a global evaluation of the studies of antibiotic prophylaxis in children with cancer indicates that there are not enough data to prepare definite guidelines for its use or avoidance in pediatric oncology, and so further studies are needed. It is not only important to define the best antibiotic regimens for the children in whom such prophylaxis is useful, but also to identify precisely those who do not need it. This would avoid the antibiotic misuse that probably occurs at the moment because many low-risk children with cancer are treated. As prophylaxis against infections requires long-term adherence to an antibiotic regimen, the attitudes and beliefs of stakeholders need to be fully considered.

Catheter-related infections in pediatric patients with cancer.

Central venous catheters (CVCs) are essential in the management of pediatric patients receiving antineoplastic therapy or bone marrow transplants, and have significantly improved their quality of life, but CVC-related infectious complications are a major source of morbidity. It has been estimated that 14-51 % of the CVCs implanted in children with malignancies may be complicated by bacteremia, and that the incidence of infections is 1.4-1.9 episodes per 1,000 CVC days. However, there are few recent data concerning the epidemiology of CVC-related infections, the prevalence of antimicrobial resistance in their etiology, or the main factors associated with an increased risk of infection by type of catheter, patient age, the type of cancer, or the presence of neutropenia. Moreover, although various new strategies have been proposed in an attempt to reduce the risk of CVC-related infections, such as catheters impregnated with antiseptics/antibiotics, lock antibiotic prophylaxis, the use of ointments at the exit site, and antithrombotic prophylaxis, their real efficacy in children has not yet been demonstrated. The management of CVC-related infections remains difficult, mainly because of the number of still open questions (including the choice of optimal antimicrobial therapy because of the increasing isolation of multiresistant bacterial strains, treatment duration, whether catheters should be removed or not, the feasibility of guidewire exchange, and the usefulness of antibiotic lock therapy) and the lack of studies of children with cancer. Only well-designed, prospective clinical trials involving pediatric cancer patients can clarify optimal prevention and treatment strategies for CVC-related infections in this population.

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.

Management and investigation of neonatal thromboembolic events: genetic and acquired risk factors.

Newborns comprise the largest group of children developing thromoboembolic events (TE(S)), due to the peculiarities of their developmental hemostatic system. Moreover, in the sick newborn, especially preterm, numerous acquired perinatal and iatrogenic conditions might result in a disturbance between coagulation and fibrinolysis, leading to thrombus formation. Nevertheless, the contribution of acquired prothrombotic disorders in the pathogenesis of thromboembolic disease in newborns remains poorly defined. Few data are currently available regarding the influence of maternal or fetal genes on thrombotic risk in the fetus and neonate. Ongoing National and International registries are partially answering these questions. The purpose of this review is to evaluate the current knowledge about the role of inherited, acquired perinatal and maternal prothrombotic risk factors in neonatal cerebral nervous system (CNS) thrombotic events and non-CNS thrombotic events.