Iron overload enhances human mesenchymal stromal cell growth and hampers matrix calcification.

BACKGROUND: Iron overload syndromes include a wide range of diseases frequently associated with increased morbidity and mortality. Several organs are affected in patients with iron overload including liver, heart, joints, endocrine glands, and pancreas. Moreover, severe bone and hemopoietic tissue alterations are observed. Because of the role of bone marrow mesenchymal stromal cells (BM-MSCs) in bone turnover and hematopoiesis, iron effects on primary BM-MSCs cultures were evaluated. METHODS: Primary human BM-MSCs cultures were prepared and the effects of iron on their proliferation and differentiation were characterized by biochemical analyses and functional approaches. RESULTS: Addition of iron to the culture medium strongly increased BM-MSCs proliferation and induced their accelerated S phase entry. Iron enters BM-MSCs through both transferrin-dependent and transferrin-independent mechanisms, inducing the accumulation of cyclins E and A, the decrease of p27(Kip1), and the activation of MAPK pathway. Conversely, neither apoptotic signs nor up-regulation of reactive oxygen species were observed. Iron inhibited both differentiation of BM-MSCs into osteoblasts and in vitro matrix calcification. These effects result from the merging of inhibitory activities on BM-MSCs osteoblastic commitment and on the ordered matrix calcification process. CONCLUSIONS: We demonstrated that BM-MSCs are a target of iron overload. Iron accelerates BM-MSCs proliferation and affects BM-MSCs osteoblastic commitment, hampering matrix calcification. GENERAL SIGNIFICANCE: Our study reports, for the first time, that iron, at concentration found in overloaded patient sera, stimulates the growth of BM-MSCs, the BM multipotent stromal cell component. Moreover, iron modulates the physiological differentiation of these cells, affecting bone turnover and remodeling.

Moyamoya syndrome in children with neurofibromatosis type 1: Italian-French experience.

Moyamoya syndrome (MMS) is the most common cerebral vasculopathy among children with neurofibromatosis type 1 (NF1). In this study, we clinically, radiologically, and genetically examined a cohort that was not previously described, comprising European children with NF1 and MMS. The NF1 genotyping had been registered. This study included 18 children. The mean age was 2.93 ± 3.03 years at the NF1 diagnosis and 7.43 ± 4.27 years at the MMS diagnosis. In seven patients, MMS was diagnosed before or at the same time as NF1. Neuroimaging was performed in 10 patients due to clinical symptoms, including headache (n = 6), cerebral infarction (n = 2), and complex partial seizures (n = 2). The remaining eight children (47%) had MMS diagnosed incidentally. Sixteen children were characterized molecularly. The features of MMS were similar between patients with and without NF1. Additionally, the NF1 phenotype and genotype were similar between children with and without MMS. Interestingly, three children experienced tumors with malignant histology or behavior. The presence of two first cousins in our cohort suggested that there may be potential genetic factors, not linked to NF1, with an additional role respect of NF1 might play a role in MMS pathogenesis. The incidental diagnosis of MMS, and the observation that, among children with NF1, those with MMS were clinically indistinguishable from those without MMS, suggested that it might be worthwhile to add an angiographic sequence to brain MRIs requested for children with NF1. A MMS diagnosis may assist in properly addressing an NF1 diagnosis in very young children who do not fulfill diagnostic criteria.

PKCßII-mediated cross-talk of TRPV1/CB2 modulates the glucocorticoid-induced osteoclast overactivity.

In this study, we investigated the role of the endovanilloid/endocannabinoid system in the glucocorticoid-induced osteoclast overactivity. Receptorial and enzymatic component of the endovanilloid/endocannabinoid system are expressed in bone cells, and dysregulated when bone mass is reduced. Moreover, blockade or desensitization of vanilloid receptor 1 (TRPV1) and/or stimulation of cannabinoid receptor 2 (CB2) are beneficial for reducing number and activity of the bone cells modulating resorption, the osteoclasts. We have treated in vitro healthy woman derived osteoclasts with methylprednisolone in presence or not of CB2 or TRPV1 agonists/antagonists, analysing the effect on osteoclast function and morphology through a multidisciplinary approach. Moreover, a treatment with a protein kinase C inhibitor to evaluate osteoclast activity and endovanilloid/endocannabinoid component expression levels was performed in osteoclasts derived from healthy subjects in presence of not of methylprednisolone. Our results show, for the first time, that the endovanilloid/endocannabinoid system is dysregulated by the treatment with methylprednisolone, that the osteoclast activity is increased and that pharmacological compounds stimulating CB2 or inhibiting TRPV1 might reduce, possible inhibiting protein kinase C beta II, the methylprednisolone-induced osteoclast over-activation, suggesting their therapeutic use for protecting from the glucocorticoid-induced bone mass loss.

CB(2) and TRPV(1) receptors oppositely modulate in vitro human osteoblast activity.

In the current study, we have investigated the effect of CB2 and TRPV1 receptor ligands on in vitro osteoblasts from bone marrow of human healthy donors. A pivotal role for the endocannabinoid/endovanilloid system in bone metabolism has been highlighted. We have demonstrated a functional cross-talk between CB2 and TRPV1 in human osteoclasts, suggesting these receptors as new pharmacological target for the treatment of bone resorption disease as osteoporosis. Moreover, we have shown the presence of these receptors on human mesenchimal stem cells, hMSCs. Osteoblasts are mononucleated cells originated from hMSCs by the essential transcription factor runt-related transcription factor 2 and involved in bone formation via the synthesis and release of macrophage colony-stimulating factor, receptor activator of nuclear factor kappa-B ligand and osteoprotegerin. For the first time, we show that CB2 and TRPV1 receptors are both expressed on human osteoblasts together with enzymes synthesizing and degrading endocannabinoids/endovanilloids, and oppositely modulate human osteoblast activity in culture in a way that the CB2 receptor stimulation improves the osteogenesis whereas TRPV1 receptor stimulation inhibits it.

Association between a polymorphism in cannabinoid receptor 2 and severe necroinflammation in patients with chronic hepatitis C.

BACKGROUND & AIMS: The cannabinoid receptor 2 (CB2) has been implicated in liver disease. The single-nucleotide polymorphism rs35761398 in cannabinoid receptor 2 gene (CNR2), which encodes the CB2, substitutes glutamine (Q) 63 with arginine (R), and reduces the function of the gene product. We investigated the effects of CNR2 rs35761398 in patients with hepatitis C virus (HCV) infection. METHODS: We studied 169 consecutive patients with asymptomatic chronic hepatitis (tested positive for anti-HCV and HCV RNA) at 2 liver units in southern Italy. First, liver biopsy samples were collected from July 2009 through December 2011. All patients were naive to antiviral therapy; CNR2 genotype was determined by polymerase chain reaction analysis. RESULTS: Patients with the CB2-63 QQ variant had higher serum levels of aminotransferase than those with the CB2-63 QR or RR variants; they also had higher histologic activity index (HAI) scores (8.6 ± 3.8) than patients without the CB2-63 RR variant (5.3 ± 3.6; P < .005) or those with the CB2-63 QR variant (5.8 ± 3.3; P < .001). Patients with the different variants of CNR2 did not differ in fibrosis stage or steatosis score. Moderate or severe chronic hepatitis (HAI score, >8) was identified more frequently (55.5%) in patients with the CB2-63 QQ variant than in those with the 63 QR (20%; P < .005) or RR variants (17.4%; P < .005). In logistic regression analysis, the CB2-63 QQ variant and fibrosis score were independent predictors of moderate or severe chronic hepatitis (HAI score, >8; P < .0001). CONCLUSIONS: The CB2-63 QQ variant of CNR2 is associated with more severe inflammation and hepatocellular necrosis in patients with HCV infection.

Preserved antibody levels and loss of memory B cells against pneumococcus and tetanus after splenectomy: tailoring better vaccination strategies.

Splenectomized patients are exposed to an increased risk of septicemia caused by encapsulated bacteria. Defense against infection is ensured by preformed serum antibodies produced by long-lived plasma cells and by memory B cells that secrete immunoglobulin in response to specific antigenic stimuli. Studying a group of asplenic individuals (57 adults and 21 children) without additional immunologic defects, we found that spleen removal does not alter serum anti-pneumococcal polysaccharide (PnPS) IgG concentration, but reduces the number of PnPS-specific memory B cells, of both IgM and IgG isotypes. The number of specific memory B cells was low in splenectomized adults and children that had received the PnPS vaccine either before or after splenectomy. Seven children were given the 13-valent pneumococcal conjugated vaccine after splenectomy. In this group, the number of PnPS-specific IgG memory B cells was similar to that of eusplenic children, suggesting that pneumococcal conjugated vaccine administered after splenectomy is able to restore the pool of anti-PnPS IgG memory B cells. Our data further elucidate the crucial role of the spleen in the immunological response to infections caused by encapsulated bacteria and suggest that glycoconjugated vaccines may be the most suitable choice to generate IgG-mediated protection in these patients.

Iron overload causes osteoporosis in thalassemia major patients through interaction with transient receptor potential vanilloid type 1 (TRPV1) channels.

The pathogenesis of bone resorption in ß-thalassemia major is multifactorial and our understanding of the underlying molecular and cellular mechanisms remains incomplete. Considering the emerging importance of the endocannabinoid/endovanilloid system in bone metabolism, it may be instructive to examine a potential role for this system in the development of osteoporosis in patients with ß-thalassemia major and its relationship with iron overload and iron chelation therapy. This study demonstrates that, in thalassemic-derived osteoclasts, tartrate-resistant acid phosphatase expression inversely correlates with femoral and lumbar bone mineral density, and directly correlates with ferritin levels and liver iron concentration. The vanilloid agonist resiniferatoxin dramatically reduces cathepsin K levels and osteoclast numbers in vitro, without affecting tartrate-resistant acid phosphatase expression. The iron chelators deferoxamine, deferiprone and deferasirox decrease both tartrate-resistant acid phosphatase and cathepsin K expression, as well as osteoclast activity. Taken together, these data show that transient receptor potential vanilloid type 1 activation/desensitization influences tartrate-resistant acid phosphatase expression and activity, and this effect is dependent on iron, suggesting a pivotal role for iron overload in the dysregulation of bone metabolism in patients with thalassemia major. Our applied pharmacology provides evidence for the potential of iron chelators to abrogate these effects by reducing osteoclast activity. Whether iron chelation therapy is capable of restoring bone health in humans requires further study, but the potential to provide dual benefits for patients with ß-thalassemia major -preventing iron-overload and alleviating associated osteoporotic changes - is exciting.

Endocrine function and bone disease during long-term chelation therapy with deferasirox in patients with ß-thalassemia major.

Iron overload in ß-thalassemia major (TM) typically results in iron-induced cardiomyopathy, liver disease, and endocrine complications. We examined the incidence and progression of endocrine disorders (hypothyroidism, diabetes, hypoparathyroidism, hypogonadism), growth and pubertal delay, and bone metabolism disease during long-term deferasirox chelation therapy in a real clinical practice setting. We report a multicenter retrospective cohort study of 86 transfusion-dependent patients with TM treated with once daily deferasirox for a median duration of 6.5 years, up to 10 years. No deaths or new cases of hypothyroidism or diabetes occurred. The incidence of new endocrine complications was 7% (P = 0.338, for change of prevalence from baseline to end of study) and included hypogonadism (n = 5) and hypoparathyroidism (n = 1). Among patients with hypothyroidism or diabetes at baseline, no significant change in thyroid parameters or insulin requirements were observed, respectively. Mean lumbar spine bone mineral density increased significantly (P < 0.001) and the number of patients with lumbar spine osteoporosis significantly decreased (P = 0.022) irrespective of bisphosphonate therapy, hormonal replacement therapy, and calcium or vitamin D supplementation. There were no significant differences in the number of pediatric patients below the 5th centile for height between baseline and study completion. Six pregnancies occurred successfully, and four of them were spontaneous without ovarian stimulation. This is the first study evaluating endocrine function during the newest oral chelation therapy with deferasirox. A low rate of new endocrine disorders and a stabilization of those pre-exisisting was observed in a real clinical practice setting.

ITP-QoL questionnaire for children with immune thrombocytopenia: Italian version validation's.

BACKGROUND: The ITP-QoL is a disease-specific questionnaire for the assessment of health-related quality of life (HRQoL) in children with immune thrombocytopenia (ITP) and their parents. The aim of this study was to test the psychometric characteristics of the ITP-QoL in the Italian pediatric population in terms of validity and reliability. PROCEDURE: Children aged 8-16 years with acute or chronic ITP and their parents were recruited in Italy. Participants completed the ITP-QoL together with other patient-reported outcomes (PROs). Reliability was calculated using Cronbach's alpha. Convergent validity was determined by means of the Pearson correlation coefficients. RESULTS: A total of 91 ITP patients, mean age of 12.11 ± 2.47 years, and their parents participated; 61.5% of the patients were female. Two patients had acute ITP and 30.2% had a moderate to severe status of ITP. Cutaneous symptoms were more frequent than mucosal symptoms. Due to item and scale analyses 20 items were deleted from the original ITP-QoL. Internal consistency of the ITP-QoL was found to be good with Cronbach's alpha exceeding α = 0.70 for all but one subscale. Concerning convergent validity "moderate" to "high" negative correlations were found between ITP-QoL and KINDL subscales. The ITP-QoL was able to discriminate between clinical subgroups such as number of days lost at school due to ITP and hospitalization. CONCLUSIONS: Our study was able to demonstrate that the Italian version of ITP-QoL (for children aged 8-16 years) is a valid and reliable instrument for the assessment of HRQoL in children with ITP.

Congenital erythrocytosis associated with gain-of-function HIF2A gene mutations and erythropoietin levels in the normal range.

Hypoxia-inducible factor 2α (HIF-2α) plays a pivotal role in the balancing of oxygen requirements throughout the body. The protein is a transcription factor that modulates the expression of a wide array of genes and, in turn, controls several key processes including energy metabolism, erythropoiesis and angiogenesis. We describe here the identification of two cases of familial erythrocytosis associated with heterozygous HIF2A missense mutations, namely Ile533Val and Gly537Arg. Ile533Val is a novel mutation and represents the genetic HIF2A change nearest to Pro-531, the primary hydroxyl acceptor residue, so far identified. The Gly537Arg missense mutation has already been described in familial erythrocytosis. However, our patient is the only described case of a de novo HIF2A mutation associated with the development of congenital polycythemia. Functional in vivo studies, based on exogenous expression of hybrid HIF-2α transcription factors, indicated that these genetic alterations lead to the stabilization of HIF-2α protein. All the identified polycythemic subjects with HIF2A mutations show serum erythropoietin in the normal range, independently of the hematocrit values and phlebotomy frequency. The erythroid precursors obtained from the peripheral blood of patients showed an altered phenotype, including an increased rate of growth and a modified expression of some HIF-2α target genes. These results suggest the novel proposal that polycythemia observed in subjects with HIF2A mutations might also be due to primary changes in hematopoietic cells and not only secondary to increased erythropoietin levels.

The 17-ß-oestradiol inhibits osteoclast activity by increasing the cannabinoid CB2 receptor expression.

Bone is a highly metabolically active tissue and its formation and resorption is at the base of bone remodelling. The critical importance of a balanced bone remodelling is demonstrated by human diseases, i.e. osteoporosis, in which a net increase in bone resorption is responsible of skeleton weakening and fracture risk. Oestrogens display anti-resorptive properties on bone metabolism. Indeed, the so-called post-menopausal osteoporosis occurs after interruption of gonad function and benefits from hormonal replacement treatment. Recently, an important role for the endocannabinoid system in the regulation of skeletal remodelling in human has also been shown. In particular, we showed that CB2 stimulation is able to reduce the number of human OCs in vitro. Here, we provide unprecedented evidence that 17-ß-oestradiol administration inhibits activity and formation of human OCs in vitro, demonstrating that oestrogens are able to induce an increase of CB2 expression probably through the recruitment of a putative oestrogens responsive element in the CB2 encoding for gene.

Neridronate improves bone mineral density and reduces back pain in ß-thalassaemia patients with osteoporosis: results from a phase 2, randomized, parallel-arm, open-label study.

Neridronate is a third generation bisphosphonate with established efficacy in metabolic bone disease. In this randomized, open-label study, 118 adults with ß-thalassaemia and bone mineral density (BMD) Z scores ≤-2·0 were randomized 1:1-500 mg calcium with 400 international unis (iu) vitamin D daily or 500 mg calcium with 400 iu vitamin D daily plus neridronate 100 mg intravenously every 90 d. Significant increases in BMD at the lumbar spine and total hip were noted in the neridronate group at 6 and 12 months from baseline (P < 0·001), and values were significantly higher than the control group at both time intervals. Neridronate also significantly decreased serum bone alkaline phosphatase and C-telopeptide of collagen type 1 levels from as early as 3 months (P = 0·04 and P < 0·001, respectively), reaching significantly lower values at 12 months compared with the control group (P < 0·05). Reductions in back pain and analgesic use were also evident, starting 3 months from commencing treatment. Treatment was well tolerated by all patients. In this largest randomized trial in thalassaemia-induced osteoporosis to date, neridronate was safe and effective in reducing bone resorption and increasing BMD. The associated reduction in back pain and improved quality of life will encourage adherence to therapy. (Clinicaltrials.gov identifier NCT01140321.).

The cannabinoid receptor type 2 Q63R variant increases the risk of celiac disease: implication for a novel molecular biomarker and future therapeutic intervention.

Celiac disease (CD) is a chronic inflammatory disease of the small bowel that occurs with the ingestion of gluten, found in several grains products. Although HLA-DQ2 variant is required for the gluten-derived peptide gliadin presentation by antigen-presenting cells to T-cells, non-HLA genetic factors account for the majority of heritable risk. Several genome-wide association studies have identified susceptibility loci for CD on chromosome 1. Cells of the immune system express the cannabinoid receptor type 2 (CB2), a plasma-membrane receptor activated by both endogenous and exogenous cannabinoids. Consistent data evidence that CB2 is linked to a variety of immune functional events and that, in the course of an inflammatory process, an increased number of receptors becomes available for activation. The cannabinoid receptor type 2 gene (CNR2; GeneID1269) maps on 1p36.11. In order to investigate the possible involvement of CB2 in CD establishment, immunohistochemistry toward CB2 receptor and CD4+ cells in small bowel biopsies from celiac children and association analysis, through TaqMan assay, of a CNR2 common missense variant, rs35761398 (CAA/CGG), resulting in the aminoacidic substitution of Glutamine at codon 63 with Arginine (Q63R), in a cohort of 327 South Italian children have been performed. We observed in this study that CB2 is up-regulated in CD small bowel biopsies and CNR2 rs35761398 is significantly associated with CD (χ(2) = 37.064; d.f. 1; p = 1.14 × 10(-9)). Our findings suggest a role of CB2 in CD. The Q63R variant, increasing more than six-fold the risk for CD susceptibility, might eventually represent a novel molecular biomarker for CD risk stratification. Indeed, we provide here further evidence that CB2 receptor plays a critical role in autoimmunity susceptibility and indicates that it represents a molecular target to pharmacologically modulate the immune components in CD.

CNR2 functional variant (Q63R) influences childhood immune thrombocytopenic purpura.

Immune thrombocytopenic purpura is an acquired autoimmune disorder that is the most common cause of thrombocytopenia in children. The endocannabinoid system is involved in immune regulation. We evaluated a common missense variant (CAA/CGG; Q63R) of the gene encoding the cannabinoid receptor type 2 (GeneID 1269) in 190 children with immune thrombocytopenic purpura and 600 healthy controls. The allelic frequencies and genotype distribution of the polymorphism in the patients were significant compared to control samples (P=0.006 and P=0.0001, respectively). Interestingly, when acute and chronic immune thrombocytopenic purpura patients were analyzed separately with respect to controls, a significant overrepresentation of the RR genotype and of the R allele was observed only for the chronic form (P=0.00021 and P=0.011, respectively). The relative odds ratio suggested the risk of developing chronic form was more than double in immune thrombocytopenic purpura children homozygous for the variant (odds ratio=2.349, 95% CI: 1.544-3.573; P<0.001).

Effect of eradication of Helicobacter pylori in children with chronic immune thrombocytopenia: a prospective, controlled, multicenter study.

BACKGROUND: The eradication of Helicobacter pylori has been associated with remission of immune thrombocytopenia (ITP) in approximately half of eradicated patients. Data on children are limited to small case series. PROCEDURE: Children from 16 centers in Italy, who were less than 18 years of age and diagnosed with chronic ITP (cITP), were screened for H. pylori infection. Positive patients underwent standard triple therapy with amoxicillin, clarithromycin, and omeprazole. The eradication response was defined as follows: complete response, platelet (PLT) count ≥ 150 × 10(9) /L; partial response, PLT count of at least 50 × 10(9) /L; no response, PLT count <50 × 10(9) /L. RESULTS: Of 244 screened patients, 50 (20%) had H. pylori infection, 37 of which received eradication therapy and completed follow-up. Eradication was successful in 33/37 patients (89%). PLT recovery was demonstrated in 13/33 patients after eradication (39%), whereas spontaneous remission was observed in 17/166 (10%) H. pylori-negative patients (P < 0.005). Responders more often required second line eradication (9/13), whereas a second cycle was required in 3/20 non-responders (P < 0.005). CONCLUSIONS: Among the large cohort of patients, those who underwent successful H. pylori eradication showed a significantly higher PLT response. Therefore, it may be appropriate to look for H. pylori and eventually eradicate it in children with cITP.

Amoxicillin-induced hemolytic anemia in a child with glucose 6-phosphate isomerase deficiency.

OBJECTIVE: To describe the first case of amoxicillin-induced nonimmune hemolytic anemia in a child with glucose-6-phosphate isomerase (GPI) deficiency. CASE SUMMARY: A 3-year-old boy with GPI deficiency was admitted for upper respiratory tract infection and fever. The patient was treated with a standard dose of amoxicillin (50 mg/kg/day). On hospital admission, the child had a chronic moderately low hemoglobin level (8.6 g/dL), but within 24 hours of the first amoxicillin dose, the hemoglobin level markedly decreased (5.8 g/dL), the reticulocyte level increased (58%), and the urine darkened. Results of the direct and indirect Coomb's tests were negative and the acute hemolytic phase ended spontaneously 8 days after amoxicillin withdrawal (hemoglobin 9.5 g/dL, reticulocytes 22%). DISCUSSION: All previous cases of amoxicillin-induced hemolytic anemia have been attributed to an immune mechanism. Given the absence of anti-reticulocyte antibodies (Coomb's test), we suggest that the amoxicillin-induced hemolytic anemia in our patient occurred via a nonimmune mechanism favored by the child's GPI deficiency. Based on a MEDLINE search, we believe this to be the first report of amoxicillin-induced nonimmune hemolytic anemia in a child with GPI deficiency. GPI deficiency has been associated with well-compensated chronic hemolytic anemia that can become clinically relevant consequent to the administration of drugs. GPI deficiency can lead to impairment of the system that removes free radicals generated by amoxicillin, thereby resulting in oxidation of hemoglobin and destabilization of red cell membranes, with acute hemolysis and severe hemoglobinuria. The Naranjo probability score was consistent with a probable relationship between the hemolytic anemia and amoxicillin therapy. CONCLUSIONS: This report reinforces the hypothesis that a drug-sensitivity reaction is closely related to a genetically transmitted enzyme deficiency.

Management of chronic childhood immune thrombocytopenic purpura: AIEOP consensus guidelines.

BACKGROUND/OBJECTIVE: The management of chronic childhood idiopathic thrombocytopenic purpura (ITP) is distinct from acute ITP. Similar to the publication on acute ITP guidelines, the AIEOP (Associazione Italiana di Ematologia e Oncologia Pediatrica) considered it appropriate to develop consensus guidelines for chronic childhood ITP to provide useful and shared information for physicians, healthcare professionals, parents and patients. DESIGN/METHODS: A preliminary, evidence-based document issued by a select group of AIEOP pediatric hematologists was discussed, modified and approved during a Consensus Conference according to procedures previously validated by the AIEOP Board. RESULTS: The guidelines give prominence to the periodical reevaluation of all the etiological hypotheses of thrombocytopenia in relation to its clinical condition. The majority of chronic ITP children do not require treatment, especially if bleeding is absent or minimal. The treatment decision depends on several factors other than the platelet count, and treatment options are suggested in relation to the therapeutic scenarios. Recommendations are given regarding support for surgery, particular hemorrhagic conditions, daily activities/sports, as well as for vaccines and drugs. Experimental treatments are also discussed.

Long-term follow-up analysis after rituximab therapy in children with refractory symptomatic ITP: identification of factors predictive of a sustained response.

We report the long-term follow-up (median 39.5 months) of 49 paediatric patients (33 females and 16 males) with refractory symptomatic immune thrombocytopenic purpura (ITP) treated with rituximab. The overall response rate was 69% (34/49 patients). Twenty-one responders had a platelet count >50 x 10(9)/l at a median 20.2 months from treatment. Kaplan-Meier analysis showed a probability of relapse-free survival (RFS) of 60% at 36 months from the first rituximab infusion. The number of infusions and a previous splenectomy did not influence overall response rate. Patients who achieved complete response were significantly older at diagnosis and first rituximab infusion than partial responders (P = 0.027). Older children displayed a significantly greater probability of sustained response (RFS) at 36 months than younger children (88.9% vs. 56.7%, P = 0.037). Earlier responses (within 20 d from treatment) were significantly associated with both complete (P = 0.004) and sustained response (P = 0.002). Only mild and transient side-effects were observed in 9/49 children; no major infections nor delayed toxicities were recorded during the follow-up.

ROBO2 gene variants are associated with familial vesicoureteral reflux.

The SLIT2 receptor ROBO2 plays a key role in the formation of the ureteric bud, and its inactivation in mice leads to supernumerary ureteric bud development, lack of ureter remodeling, and improper insertion of the ureters into the bladder. Recently, two heterozygous ROBO2 missense mutations were identified in two families with primary vesicoureteral reflux occurring in combination with congenital anomalies of the kidney and urinary tract (VUR/CAKUT). This study investigated a possible causal role of ROBO2 gene variants in 95 unrelated patients with primary VUR (n = 78) or VUR/CAKUT. Eighty-two percent of all patients had a family history of genitourinary anomalies. Twenty-four ROBO2 gene variants were identified by direct sequencing of all 26 exons and the exon-intron boundaries. Of these, four led to amino acid substitutions: Gly328Ser, Asn515Ile, Asp766Gly, and Arg797Gln. When the families were examined, the missense variants co-segregated with VUR (three families) or VUR/CAKUT (one family). These variants were not found in 190 control subjects, and the affected amino acids have been conserved through evolution. In conclusion, a relatively high frequency of ROBO2 variants (5.1%) was found in familial cases; however, functional studies and validation in other cohorts are warranted.

Management of acute childhood idiopathic thrombocytopenic purpura according to AIEOP consensus guidelines: assessment of Italian experience.

BACKGROUND: Consensus guidelines for diagnosis and treatment of acute childhood idiopathic thrombocytopenic purpura (ITP) were published in 2000 by the Italian Association of Pediatric Haematology and Oncology (AIEOP). The assessment of guideline implementation was the primary objective of the present study. PATIENTS AND METHODS: Information on each newly diagnosed case of ITP referring to centres conforming with the guidelines was obtained by a questionnaire. RESULTS: Data concerning 609 new cases of acute childhood ITP were collected including 346 (56.8%) asymptomatic-paucisymptomatic forms (type A), 262 (43%) intermediate clinical forms (type B), and 1 (0.2%) severe form (type C). At diagnosis, 82% of cases were hospitalized. Age, platelet count and duration of hospitalization were significantly different in type A and type B cases. Of the total number of cases, 25% were kept under observation, 38.6% received intravenous immunoglobulins, 23.9% oral or parenteral steroids, and 12.7% other treatments. The initial treatment turned out to be appropriate for 428 cases (72.2%), of uncertain appropriateness in 71 (11.9%), and inappropriate in 95 cases (15.9%). The total level of implementation was 84.1%. CONCLUSIONS: A high rate of guideline implementation was observed during the study period. The guidelines should be reviewed taking into account more recent evidence.