Biological Features of Bone Marrow Mesenchymal Stromal Cells in Childhood Acute Lymphoblastic Leukemia.

OBJECTIVE: Mesenchymal stromal cells (MSCs) have a supportive role in hematopoiesis and as components of the bone marrow (BM) microenvironment may present alterations during acute lymphoblastic leukemia (ALL) and be affected by chemotherapeutic agents. We examined the biological and functional characteristics of MSCs in ALL diagnosis and treatment and their effect on MSC qualitative properties. MATERIALS AND METHODS: Immunophenotypic characterization, evaluation of clonogenicity, and proliferative capacity were measured. Apoptotic features, cell-cycle analysis, and stromal cell-derived factor 1α and angiopoietin-1 levels in MSC supernatant at diagnosis and in different phases of treatment were assessed. Chemotherapy was administered according to the Berlin-Frankfurt-Munster-2000 protocol. BM samples from children with solid tumors without BM involvement were used as the control group. RESULTS: The morphology, the immunophenotypic profile, and the apoptotic characteristics of the MSCs were not affected by leukemia. The secretion of factors involved in the trafficking of hematopoietic cells in the BM seems to be upregulated at diagnosis in comparison to the treatment phases. MSCs are influenced by the disease in terms of their functional characteristics such as clonogenicity and proliferation rate. These effects cease as soon as treatment is initiated. Chemotherapy does not seem to exert any effect on any of the MSC features examined. CONCLUSION: MSCs from children with ALL are affected by their interaction with the leukemic environment, but this phenomenon ceases upon treatment initiation, while no effect is observed by chemotherapy itself.

Non-tuberculous mycobacterial cervical lymphadenitis in the immunocompetent child: diagnostic and treatment approach.

Non-tuberculous mycobacterial disease in the otherwise well child commonly presents as a localized, slow-progressing, cervicofacial lymphadenopathy. Despite recent advances, several aspects of the susceptibility to and the course of the disease remain to be better understood, and diagnosis and management of non-tuberculous mycobacterial lymphadenitis in children are often controversial. Differential diagnosis should include other infections, in particular tuberculosis, local cysts and malignancies. In the majority of cases, untreated disease progresses to spontaneous drainage, fistula formation and scarring and a high index of clinical suspicion is necessary for timely diagnosis and treatment. Excisional surgery seems to remain the gold standard. Medical treatment might be considered as an appropriate alternative in case there is a high risk of surgical complications or in case surgery has already been unsuccessful. Family reassurance and the watch-and-wait approach may be an option in milder disease.

Expression levels of ASNS in mesenchymal stromal cells in childhood acute lymphoblastic leukemia.

Increased levels of asparagine synthetase (ASNS), an enzyme producing intracellular asparagine, have been implicated in the development of asparaginase resistance. The aim of this study was to assess ASNS mRNA and protein expression in bone marrow cell populations of children with acute lymphoblastic leukemia (ALL). Bone marrow mononuclear cells at diagnosis, day 33 of treatment, and after completion of chemotherapy were isolated and studied. ASNS mRNA expression was assessed by real-time PCR, and protein levels by Western blot. Our results indicate that MSC ASNS mRNA expression is upregulated in ALL samples compared to controls. ASNS expression of mesenchymal stromal cells (MSC) was found to be 2.3 times higher than that of blasts at diagnosis of ALL. We also observed that the values of the ASNS mRNA of MSC seem to reach a peak at diagnosis, and tend to decline with treatment. No correlation was found between the ASNS mRNA and protein levels. Chemotherapy does not exert any effect on the protein expression. Variability of asparaginase-induced effect may be attributable to factors involved in the interaction of hematopoietic cells with their microenvironment.

Idiopathic thrombocytopenic purpura in childhood: twenty years of experience in a single center.

BACKGROUND: Idiopathic thrombocytopenic purpura (ITP) is an autoimmune disorder with a variable clinical course. METHODS: A retrospective analysis was carried out of ITP patients presenting to a pediatric hematology-oncology department during a period of 20 years, with a focus on treatment and outcome. RESULTS: One hundred and twenty-four cases were recorded (mean patient age, 8.4 years). Forty-nine children (39.5%) had platelet counts <10,000/µL at diagnosis. No episode of severe bleeding was observed. Peak incidence was observed during spring and summer. Respiratory infections proceeded in 58% of cases. Treatment consisted of i.v. immunoglobulin (IVIG) in 93 children at four dosing schedules. Sixteen children received corticosteroids, 10 children received anti-D immunoglobulin and 14 received no treatment. Recovery was observed in 67% of children on IVIG and in 50% on anti-D globulin. Eight patients did not respond initially and received corticosteroids. Three children with refractory thrombocytopenia received anti-CD20 (rituximab). Fourteen children (11%) had persistent/chronic disease. In 10 of them recovery was observed in 13 months-8 years. Splenectomy was performed in six children with resistant/chronic disease. CONCLUSION: ITP has a benign course in the majority of cases. Anti-D globulin can effectively be used as an alternative first-line treatment. Rituximab can successfully be used in refractory cases, while splenectomy has currently limited indications.

Yersinia enterocolitica infection mimicking surgical conditions.

Yersinia enteritis may present with alarming gastrointestinal manifestations. The aim of this study was to review the cases of children admitted to a general hospital with a preliminary diagnosis of surgical nature and subsequently proven to be infected by Yersinia enterocolitica. All cases of children aged less than 14 years with stool cultures positive for Y. enterocolitica during the 12-year period January 1993 through December 2004 were analyzed. Y. enterocolitica was isolated from the stools of 71 children with gastrointestinal manifestations; 27 children were treated as outpatients and 44 were hospitalized. Six were admitted to the Pediatric Surgery Department (13.6% of the total hospitalizations and 8.4% of all Y. enterocolitica cases). Four of the Pediatric Surgery patients presented with abdominal pain and right lower quadrant tenderness. The preliminary diagnosis of appendicitis was excluded during hospitalization and none of them underwent appendectomy. The other two children were admitted for vomiting initially attributed to a preceding head injury and for diarrhea and a perianal abscess. Two children were given antibiotics and all had an excellent outcome. Y. enterocolitica enteritis manifestations can infrequently mimic appendicitis or other surgical conditions but should remain in the differential diagnosis of children presenting with an acute abdomen.

The impact of mode of delivery and gestational age on cord blood hematopoietic stem/progenitor cells.

Human cord blood has been successfully used as an alternative source of hematopoietic stem cells suitable for transplantation. The aim of this study was to assess the impact of gestational age and the mode of delivery on cord blood hematopoietic stem/progenitor cell characteristics. The mode of delivery does not seem to affect either the replating capacity of hematopoietic progenitors colony-forming unit-granulocyte-macrophage or the cord blood content in CD34(+) cells. The higher percentage of CD34(+) cells in cord blood from preterm deliveries compared to full-term ones indicates that hematopoietic progenitors from preterm cord blood may be suitable for transplantation. These findings should be taken into consideration when selection of cord blood units is required for potential use in transplantation.