The role of children's bone marrow mesenchymal stromal cells in the ex vivo expansion of autologous and allogeneic hematopoietic stem cells.

The recognition of the role of Mesenchymal Stromal Cells (MSC) in hematopoiesis, as part of the bone marrow microenvironment, renewed the interest for cord blood (CB) ex vivo expansion as a source of HSC for transplantation. MSC from children are recognized to have different biological properties compared to the ones from adults. The current study focuses on the evaluation of the effects of children's bone marrow MSC on the ex vivo expansion capacity of both allogeneic cord blood and autologous bone marrow (BM) CD34(+) hematopoietic stem cells (HSCs) when used as a cell feeder layer with or without recombinant cytokines. Our results showed that children's bone marrow-derived MSC expand more primitive populations in co culture with CD34 and that the expansion is further enhanced when the culture is supplemented with growth factors. No additive effect was seen either with the early- or late-acting growth factors' cocktails used. Biological features of CB hematopoietic progenitors seem to make them more suitable than their BM counterparts for ex vivo expansion. Clinical implementation will be facilitated by methodological standardization and guidelines' establishment.

The effect of maternal flora on Candida colonisation in the neonate.

Colonisation may be the first step for the development of Candida infection. The source of neonatal colonisation is thought to be the hospital environment or the maternal vaginal tract. This study investigated to what extend Candida isolates in neonates are similar to isolates from their mother's vaginal tract. Vaginal samples were collected from 347 pregnant women within 48 h before delivery. Samples from oral and rectal mucosa of their neonates were collected within 24-72 h after delivery, were cultured and yeast species were identified. Antifungal susceptibility tests against six antifungal agents were performed. All paired isolates from mother and infant were genotyped by pulse field gel electrophoresis. A total of 82 mothers and of 16 infants were found colonised by Candida spp. C. albicans was the most common species in pregnant women (n = 68) followed by C. glabrata (n = 11). Only C. albicans was isolated from infants, mainly (14/16) from rectal site. All colonised neonates were born to mothers colonised by C. albicans. Candida genotyping revealed identical strains in all investigated neonate-mother pairs. All isolates were susceptible to amphotericin B. Our findings strongly suggest that vertical transmission has the principal role in the neonatal colonisation by C. albicans in the very first days of life.

CD64-Neutrophil expression and stress metabolic patterns in early sepsis and severe traumatic brain injury in children.

BACKGROUND: Critical illness constitutes a serious derangement of metabolism. The aim of our study was to compare acute phase metabolic patterns in children with sepsis (S) or severe sepsis/septic shock (SS) to those with severe traumatic brain injury (TBI) and healthy controls (C) and to evaluate their relations to neutrophil, lymphocyte and monocyte expressions of CD64 and CD11b. METHODS: Sixty children were enrolled in the study. Forty-five children with systemic inflammatory response syndrome (SIRS) were classified into three groups: TBI (n = 15), S (n = 15), and SS (n = 15). C consisted of 15 non- SIRS patients undergoing screening tests for minor elective surgery. Blood samples were collected within 6 hours after admission for flow cytometry of neutrophil, lymphocyte and monocyte expression of CD64 and CD11b (n = 60). Procalcitonin (PCT), C-reactive protein (CRP), glucose, triglycerides (TG), total cholesterol (TC), high (HDL) or low-density-lipoproteins (LDL) were also determined in all groups, and repeated on day 2 and 3 in the 3 SIRS groups (n = 150). RESULTS: CRP, PCT and TG (p < 0.01) were significantly increased in S and SS compared to TBI and C; glucose did not differ among critically ill groups. Significantly lower were the levels of TC, LDL, and HDL in septic groups compared to C and to moderate changes in TBI (p < 0.0001) but only LDL differed between S and SS (p < 0.02). Among septic patients, PCT levels declined significantly (p < 0.02) with time, followed by parallel decrease of HDL (p < 0.03) and increase of TG (p < 0.02) in the SS group. Neutrophil CD64 (nCD64) expression was higher in patients with SS (81.2%) and S (78.8%) as compared to those with TBI (5.5%) or C (0.9%, p < 0.0001). nCD64 was positively related with CRP, PCT, glucose, and TG (p < 0.01) and negatively with TC, LDL, and HDL (p < 0.0001), but not with severity of illness, hematologic indices, length of stay or mechanical ventilation duration. CONCLUSIONS: In sepsis, the early stress-metabolic pattern is characterized by a high (nCD64, glucose, TG) - low (TC, HDL, LDL) combination in contrast to the moderate pattern of TBI in which only glucose increases combined with a moderate cholesterol - lipoprotein decrease. These early metabolic patterns persist the first 3 days of acute illness and are associated with the acute phase CD64 expression on neutrophils.

Skills of primary healthcare physicians in paediatric cardiac auscultation.

AIM: To evaluate the performance of primary healthcare physicians in paediatric cardiac auscultation and the impact of a multimedia-based teaching intervention. METHODS: A total of 106 primary healthcare physicians (77 paediatricians, 14 general practitioners and 15 medical graduates) attended four paediatric cardiac auscultation teaching courses based on virtual patients' presentation (digital phonocardiography). Their auscultatory performance was documented at the beginning of each course and at the end of two of the courses. RESULTS: Participants initially detected 73% of abnormal murmurs and 17% of additional sounds, while 22% of innocent murmurs were interpreted as abnormal. Overall cardiac auscultation performance, assessed by a combined auscultation score, was low and independent of training level (graduates: 39.5/trainees: 42.8/board certified: 42.6, p = 0.89) or specialty (paediatricians: 42.7/general practitioners: 43.1, p = 0.89). Multimedia-based teaching was associated with a significant improvement in abnormal murmur (92.5%) and additional sound (40%) detection (p < 0.001), while 25% of innocent murmurs were still interpreted as abnormal (p = 0.127). CONCLUSION: Clinical skills of primary healthcare physicians in paediatric cardiac auscultation, independent of training level or specialty, still leave potential for improvement. Multimedia-based teaching interventions represent an effective means of improving paediatric cardiac auscultatory skills.

Enhanced levels of the apoptotic BAX/BCL-2 ratio in children with acute lymphoblastic leukemia and high-risk features.

It has been suggested that leukemia is characterized by an impaired balance between the proliferation of blood cells and their capacity to undergo apoptosis. The aim of this study was to examine the expression of key molecules related to apoptosis (BCL-2, BAX, FAS, FAS-L) in children with acute lymphoblastic leukemia (ALL). Measurement of BCL-2 and BAX mRNA was performed by quantitative real-time PCR, and membrane expression of FAS and FAS-L was assessed by flow cytometry in bone marrow mononuclear cells, both at diagnosis and at remission following induction chemotherapy. At diagnosis, increased levels of the apoptotic BAX/BCL-2 ratio were observed in children older than 10 years and with higher white blood cell counts. A DNA index < 1.16 was associated with increased BAX/BCL-2, both at diagnosis and at remission, and the del(9p) chromosome abnormality with increased BAX/BCL-2 at remission. The expression of the apoptotic receptor FAS was significantly higher at remission compared to diagnosis, which might reflect enhanced sensitivity of the leukemic clone to apoptosis and response to treatment. Altogether, our results highlight the association of apoptosis-related genes with clinical and cytogenetic prognostic parameters in pediatric ALL. A better understanding of the mechanisms and regulation of apoptosis should enable the design of novel targeted therapies for these patients.

A national registry of haemoglobinopathies in Greece: deducted demographics, trends in mortality and affected births.

Haemoglobinopathies are the most common hereditary disorders in Greece. Although there is a successful national prevention program, established 35 years ago, there is lack of an official registry and collection of epidemiological data for haemoglobinopathies. This paper reports the results of the first National Registry for Haemoglobinopathies in Greece (NRHG), recently organized by the Greek Society of Haematology. NRHG records all patients affected by thalassaemia major (TM), thalassaemia intermedia (TI), "H" Haemoglobinopathy (HH) and sickle cell disease (SCD). Moreover, data about the annual rate of new affected births along with deaths, between 2000 and 2010, are reported. A total of 4,506 patients are registered all over the country while the number of affected newborns was significantly decreased during the last 3 years. Main causes for still having affected births are: (1) lack of medical care due to financial reasons or low educational level; (2) unawareness of time limitations for prenatal diagnosis (PD); due either to obstetricians' malpractice or to delayed demand of medical care of couples at risk; and (3) religious, social or bioethical reasons. Cardiac and liver disorders consist main causes for deaths while life expectancy of patients lengthened after 2005 (p < 0.01). The NRHG of patients affected by haemoglobinopathies in Greece provides useful data about the haemoglobinopathies in the Greek population and confirms the efficacy of the National Thalassaemia Prevention Program on impressively decreasing the incidence of TM and sickle cell syndromes.

Maternal smoking during pregnancy and risk for childhood leukemia: a nationwide case-control study in Greece and meta-analysis.

BACKGROUND: Maternal smoking during pregnancy has been often implicated in the development of childhood leukemia with ambiguous results. Hence, we conducted a meta-analysis aiming to summarize current evidence and quantify any tentative impact. PROCEDURE: We retrieved one cohort (553 leukemias compared to 1,440,542 children), 20 case-control studies and also analyzed the updated Greek case-control dataset with unpublished data, yielding in total 11,092 cases and 25,221 controls. RESULTS: Odds ratios reported in the studies included ranged from 0.70 to 2.20 for acute lymphocytic (ALL) and from 0.60 to 2.17 for acute myelocytic leukemia (AML). The combined effect regarding the association of maternal smoking (any vs. no) and leukemia risk was 1.03 for ALL (95% CI = 0.95-1.12, random effects model) and 0.99 for AML (95% CI = 0.90-1.09, fixed effects model). The results remained unchanged when sensitivity analyses were undertaken of studies reporting same maternal smoking periods, those focusing only on childhood leukemia deaths or investigations which did not clearly define AML subtype. CONCLUSIONS: The findings of the meta-analysis challenge the limits of traditional epidemiology to provide sound inferences when point estimates of constituent studies range around the null. In particular, this study provides no support to a hypothesis linking maternal smoking during pregnancy with subsequent development of main childhood leukemia subtypes. Further investigations employing molecular and genetic epidemiology, however, might be needed in the hope to reveal even minimal risks pertaining individuals with specific susceptibility to tobacco compounds who sustain high environmental exposures prenatally or postnatally.

In vitro fertilization and risk of childhood leukemia in Greece and Sweden.

BACKGROUND: Cancer risk in children born after in vitro fertilization (IVF) remains largely unknown. We aimed to investigate risk of leukemia and lymphoma following IVF using two nationwide datasets. METHODS: The hospital-based case-control study in Greece derived from the National Registry for Childhood Hematological Malignancies (1996-2008, 814 leukemia and 277 lymphoma incident cases with their 1:1 matched controls). The Swedish case-control study was nested in the Swedish Medical Birth Register (MBR) (1995-2007, 520 leukemia and 71 lymphoma cases with their 5,200 and 710 matched controls) with ascertainment of incident cancer cases in the National Cancer Register. Study-specific and combined odds ratios (OR) were estimated using conditional logistic regression, with adjustment for possible risk factors. RESULTS: Nationwide studies pointed to similar size excess risk of leukemia following IVF, but to a null association between IVF and lymphoma. The proportion of leukemia cases conceived through IVF was 3% in Greece and 2.7% in Sweden; prevalence of IVF in matched controls was 1.8% and 1.6%, respectively. In combined multivariable analyses, the increased risk of leukemia was confined to age below 3.8 years (OR = 2.21; 95% confidence interval, CI: 1.27-3.85) and to acute lymphoblastic leukemia (ALL) (OR = 1.77; 95% CI: 1.06-2.95) with no sufficient evidence of excess risk for other leukemias (OR = 1.34; 95% CI: 0.38-4.69). Following IVF, OR for ALL was 2.58 (95% CI: 1.37-4.84) before age 3.8 and 4.29 (95% CI: 1.49-12.37) before age 2 years. CONCLUSIONS: IVF seems to be associated with increased risk of early onset ALL in the offspring.

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.

Frequency, clinical characteristics, and genotype distribution of rotavirus gastroenteritis in Greece (2007-2008).

Rotavirus is the leading cause of acute gastroenteritis among young children worldwide. A prospective multi-center study was conducted (2007-2008) in five Pediatric Hospitals to determine the prevalence, the clinical characteristics, and genotype distribution of rotavirus infection in Greece. Faecal samples were examined for the presence of group A rotavirus antigen by immunochromatography. Rotavirus strains were subjected to G and P genotyping by reverse-transcriptase polymerase chain reaction (PCR) and sequencing. A total of 393 children (216 boys) of median age 23 months, participated in the study. Rotavirus was the cause of acute gastroenteritis in 166 children, 42.3% (CI 95%, 37.4-47.1%) of non-hospitalized and 47.8% (CI 95%, 41.7-53.9%) of hospitalized patients. Rotavirus gastroenteritis occurred between December and April in 78.6% of the cases. Most children with RVG (77.8%) were between 3 months and 3 years old. The mean value of Clark severity score was 12.9 ± 5.1 for RVG and 10.5 ± 4.9 for non-RVG (P < 0.01). Genotypes were determined in 117 strains and their distribution was as following: G1P[8], 49%; G2P[4], 31%; G4P[8], 10%; G9P[8], 9%; and G8P[14], 1%. In conclusion, rotavirus is a frequent cause of acute gastroenteritis in Greece. The genotypes circulating are similar with those of other European countries.

CNS imaging is a key diagnostic tool in the evaluation of patients with CFC syndrome: two cases and literature review.

Cardio-facio-cutaneous (CFC) syndrome is characterized by a variable degree of cognitive impairment, and multiple congenital anomalies including characteristic facies, cardiac, and ectodermal abnormalities. CFC syndrome is caused by mutations in the genes BRAF, MEK1, or MEK2. Here we provide a follow-up report on two patients presenting distinct facial appearance and other features of the syndrome, and we present the first molecular evidence of paternal origin for a CFC-causing germline mutation. Brain imaging revealed a lipoma of the corpus callosum and periventricular leukoencephalopathy as well as a hypoplastic corpus callosum, and defects in myelinization, in each patient, respectively. A review of the literature showed that, although non-specific, ventriculomegaly, hydrocephalus, and cortical atrophy represent the most frequent imaging findings of brain anomalies in CFC syndrome. CNS abnormalities are significant diagnostic features of CFC syndrome and a brain MRI is recommended in individuals diagnosed with CFC or suspected of having CFC syndrome.

Pelvic hypoplastic kidney in a patient with Williams-Beuren syndrome.

Renal and renovascular abnormalities constitute features of the Williams-Beuren syndrome (WBS), one multisystem genetic disorder in childhood, caused by a microdeletion of chromosome 7. We report a 12 years old boy who was diagnosed with WBS and had an ectopic pelvic hypoplastic left kidney, detected by ultrasonography and renal scintigraphy. Dystopic hypoplastic kidney is an infrequent finding in patients with WBS and our report showed the importance of a complete clinical and laboratory study of renal function in WBS.

Comparative study of stemness characteristics of mesenchymal cells from bone marrow of children and adults.

BACKGROUND AIMS: Age-related changes that could affect the biologic features of mesenchymal stromal cells (MSC), such as a decrease in proliferation and osteoblast differentiation capacity and an increase of senescence markers and apoptosis, have been reported recently. The aim of this study was the evaluation of age-related characteristics and the correlation of age with the functional properties of MSC. METHODS: The doubling time (DT), colony-forming unit­fibroblast (CFU-F) colonies and surface antigen expression of MSC isolated from bone marrow (BM) of children (C-MSC) were compared with those from adults (A-MSC). The expression of Oct-4 and Nanog transcripts and the relative telomere length were evaluated in both groups. RESULTS: DT values were lower in C-MSC compared with A-MSC, and a higher CFU-F count was observed in children. However, the expression of Oct-4 and Nanog did not differ between C-MSC and A-MSC and was not correlated with the proliferative capacity. The telomere length was significantly higher in C-MSC compared with A-MSC. CONCLUSIONS: These data suggest that children's BM-derived MSC could be a more advantageous source of these cells for tissue engineering and cell therapy.

Phenotype-genotype correlation of a patient with a "balanced" translocation 9;15 and cryptic 9q34 duplication and 15q21q25 deletion.

We report on a 2-year-old boy with intellectual disabilities, distinctive facies, hypotonia, cardiac, and renal malformations. During his infancy he had recurrent episodes of apnea, cyanosis, and bradycardia. Chromosomal analysis showed a de novo apparently balanced translocation 46,XY,t(9;15)(q31;q26)dn. The use of array-comparative genomic hybridization (CGH) however, revealed the presence of additional cryptic complex chromosomal rearrangements involving a approximately 5-5.8 Mb distal duplication on chromosome 9 (9q34.1 --> 9q34.3), and deletions on three separate regions of chromosome 15 adding to approximately 8.1-12.2 Mb (15q21.2 --> 15q21.3, 15q22.31 --> 15q23, 15q25.1 --> 15q25.2). During confirmation with fluorescence in situ hybridization (FISH) an inversion was unexpectedly revealed on chromosome 15 (15q21.1 --> 15q21.2). To our knowledge this is the first patient reported whose phenotype is due to partial trisomy 9q, and complex interstitial deletions of 15q, not involving the Prader-Willi/Angelman region and encompassing the critical region 15q21q25. We provide correlation between the clinical findings of our patient and the phenotype of the 9q34 duplication syndrome, the 15q21, and the 15q25 deletion syndromes.

Adipocytokines in relation to Hodgkin lymphoma in children.

This case-control study aims to explore the association of serum adiponectin/leptin with childhood Hodgkin lymphoma (HL). Study participants were 75 children with histologically confirmed HL, registered in the Nationwide Registry for Childhood Haematological Malignancies and 75 age- and gender-matched controls. Multiple conditional logistic regression analyses were performed, adjusting for sociodemographic and lifestyle parameters. Adiponectin levels were consistently higher among cases in all models with ORs >1.25; 95% CIs ranging from 0.9 to 1.8 and P-values from 0.09 to 0.20. By contrast, there was no association of serum leptin with HL. In conclusion, elevated serum adiponectin might be a risk factor for childhood HL.

Serum carnitine levels in childhood leukemia.

In patients with malignancies, the system of carnitine seems abnormally expressed. The serum total, free, and acyl carnitine levels in 40 children and adolescents with acute leukemia were determined using electrospray tandem mass spectrometry in 4 different phases of the disease: at the diagnosis, 1 year after the initiation of chemotherapy, at the end of treatment, and 2.4+/-1.668 years after the completion of chemotherapy. The age, sex, hemoglobin values, serum biochemistry, somatometric features of the patients, and the risk group of the disease were examined. Although the carnitine levels were found higher in patients compared with the control group from diagnosis to treatment completion, statistically significant decrease in carnitine levels was observed in patients within different phases of the disease especially during induction and consolidation treatment (phase A to B) for both free and total (P=0.023) carnitine. In addition, a statistically significant recovery in carnitine levels was observed between phase B (end of intensive chemotherapy) and D (some years after the completion of treatment) for free and total carnitine (P=0.054 and 0.035, respectively). No statistical correlation was documented between the carnitine levels and somatometric parameters or other variables studied. In conclusion, a significant transient decrease in the levels of carnitine during the treatment was observed in children with acute leukemia. Further studies are required to clarify the role of carnitine status in patients with malignancies and possibly the necessity of carnitine supplementation during chemotherapy administration.

Genetic variants in immunoregulatory genes and risk for childhood lymphomas.

To investigate whether single nucleotide polymorphisms (SNPs) in key cytokine and innate immunity genes influence risk for childhood lymphomas, we genotyped 37 children with Hodgkin's (HL) and 48 with non-Hodgkin's lymphoma (NHL), aged (1 month-14 yr), along with their 85 age- and gender-matched controls suffering from mild medical conditions. Genotypic analysis was performed for 10 SNPs from nine genes with important role in immunoregulatory pathways (IL4, IL4R, IL6, IL10, IL12, IL18, TNFalpha, IFNgamma, CD14). Analysis of SNPs genotypes revealed that the CD14 -159 C>T polymorphism was associated with significantly increased risk for HL regarding both the CC and CT genotypes (OR(CC): 5.36; 95% CI, 1.30-22.14; P = 0.02, OR(CT): 3.76; 95% CI, 1.00-14.16; P = 0.05). An indicative association between IL18-137 G>C polymorphism with the CC genotype and NHL did not reach, however, statistical significance (OR(CC), 3.78; 95% CI, 0.87-16.38; P = 0.08). In conclusion, our findings suggest that genetic variation in the CD14-159 loci may be associated with childhood HL risk; these preliminary findings need to be further confirmed in sizeable multi-centre studies along with determination of cytokines, which could provide an insight on the biologic basis underlying these findings.

Gene polymorphisms in childhood ALL.

Acute lymphoblastic leukemia (ALL) is the most common malignancy diagnosed in children. Inherited predisposition and exposure to exogenous leukemogenic agents have been investigated as potential risk factors. Current therapy results in 5-year event-free survival exceeding 80% in children in developed countries. Predisposition to ALL and event-free outcome seems to be influenced by polymorphisms on genes involved in several metabolic pathways. The purpose of this review is to discuss the findings of different studies upon the role of gene polymorphisms in childhood ALL.

Resistance against broad-spectrum beta-lactams among uropathogens in children.

The aim of this study was to investigate the prevalence trends and risk factors for urinary tract infection (UTI) caused by Enterobacteriaceae resistant to broad-spectrum beta-lactams in children. All Enterobacteriaceae uropathogens from children <15 years during the 11-year period 1997-2007 were included, and risk factors were evaluated. Of 523 Enterobacteriaceae isolated from 473 children, 30 (5.73%) were phenotypically resistant to broad-spectrum beta-lactams (18 Escherichia coli, ten Klebsiella spp, one Enterobacter spp, and one Citrobacter spp). The prevalence of resistance increased during the study period (p = 0.031). Resistance to cefoxitin was common (26/30), pointing to AmpC enzyme expression, and 2/30 isolates were resistant to carbapenems. Resistant Enterobacteriaceae were often community acquired (22/30, 73.3%) and related to male gender (p < 0.05), urinary tract abnormalities (p < 0.05), prophylactic antibiotics (p < 0.0001), longer hospitalization (p < 0.001), and UTI recurrences (p < 0.001). Co-resistance was more likely for cotrimoxazole, gentamicin, and ciprofloxacin (p < 0.0001). In conclusion, our study points to increasing prevalence of Enterobacteriaceae uropathogens resistant to broad-spectrum beta-lactams in the community setting, which limits the utility of first-line antibiotics and questions the validity of using prophylaxis after a first UTI episode.

Cervical lymphadenopathy in childhood epidemiology and management.

Cervical lymphadenopathy (CL) is common in childhood. The aim of this study is to evaluate the etiology, follow-up, and treatment of persistent CL. The authors studied retrospectively 50 children with CL, hospitalized at the Department of Pediatrics and Pediatrics Surgery. Patients underwent ultrasonography. Thirty-six percent presented abnormal ultrasonographic image and underwent excisional biopsy. Biopsies revealed 4 thyroglossal cysts, 3 branchial cysts, 1 hemangioma, 2 sebaceous cysts, 1 dermoid cyst, 5 occurrences of tuberculosis lymphadenitis, 1 occurrence of Bartonella henselae lymphadenopathy, and 1 case of non-Hodgkin lymphoma. In conclusion, CL is usually a benign finding; bacterial and viral infections are the most common causes. Ultrasonography help in etiology and follow-up of CL.