Paola Francalanci

Genotype-Phenotype Relationship in Human ATP6i-Dependent Autosomal Recessive Osteopetrosis

Autosomal-recessive osteopetrosis is a severe genetic disease caused by osteoclast failure. Approximately 50% of the patients harbor mutations of the ATP6i gene, encoding for the osteoclast-specific a3 subunit of V-ATPase. We found inactivating ATP6i mutations in four patients, and three of these were novel. Patients shared macrocephaly, growth retardation and optic nerve alteration, osteosclerotic and endobone patterns, and high alkaline phosphatase and parathyroid hormone levels. Bone biopsies revealed primary spongiosa lined with active osteoblasts and high numbers of tartrate-resistant acid phosphatase (TRAP)-positive, a3 subunit-negative, morphologically unremarkable osteoclasts, some of which located in shallow Howship lacunae. Scarce hematopoietic cells and abundant fibrous tissue containing TRAP-positive putative osteoclast precursors were noted. In vitro osteoclasts were a3-negative, morphologically normal, with prominent clear zones and actin rings, and TRAP activity more elevated than in control patients. Podosomes, alphaVbeta3 receptor, c-Src, and PYK2 were unremarkable. Consistent with the finding in the bone biopsies, these cells excavated pits faintly stained with toluidine blue, indicating inefficient bone resorption. Bone marrow transplantation was successful in all patients, and posttransplant osteoclasts showed rescue of a3 subunit immunoreactivity.

Malignant Pancreatic Endocrine Tumor in a Child With Tuberous Sclerosis

Tuberous sclerosis complex (TSC) is an autosomal dominant condition whose signs and symptoms may vary from a few hypopigmented skin spots to epilepsy, severe mental retardation, and renal failure. The disease is caused by mutations in either TSC1 or TSC2 gene, at chromosome 9q34 and 16p13.3. Inactivation of both alleles at TSC1 or TSC2 loci is associated with the development of hamartomas in different organs, and only rarely with malignant neoplasms. In this study we present a 6-year-old boy with TSC and with a malignant islet cell tumor of the pancreas. Mutation analysis of DNA extracted from peripheral blood cells of the patient identified an R1459X de novo mutation in exon 33 of the TSC2 gene. Immunohistochemical analysis with anti-tuberin antibodies on paraffin-embedded tissue sections showed loss of tuberin immunostaining in tumor cells but normal expression in residual normal pancreas. DNA analysis of tumor and normal cells showed chromosome 16p13 loss of heterozygosity in malignant pancreatic islet cell tumor but not in normal pancreas. These findings suggest a role for tuberin, the TSC2 gene product, in the pathogenesis of malignant pancreatic endocrine tumor.

Clinical role of calprotectin assay in determining histological relapses in children affected by inflammatory bowel diseases

Background: Inflammatory bowel diseases (IBD) are characterized by periods of remission with recurrent episodes of symptom exacerbation because of acute intestinal inflammation, which is correctly evaluated by endoscopy with biopsy sampling. However, many surrogate markers of intestinal inflammation, including fecal calprotectin (FC), are detected as potential predictors of mucosal inflammation in IBD patients. The aim of our study was to retrospectively assess the clinical efficacy of the calprotectin assay in determining histological relapses of pediatric IBD patients. Methods: We retrospectively reviewed the histological examinations, clinical records, and FC values of patients who had undergone colonoscopy at our hospital over an 8‐year period, from December 31, 1998, to December 31, 2006. Only patients with a first histological examination showing a quiescent IBD who submitted to a second histological examination during the next 3 years were selected. Results: Seventy‐three IBD patients, all with a first biopsy showing a quiescent IBD, were studied; at the second histological examination, 32 presented with relapse and 41 presented with remission. Relapsed patients showed significantly increased FC levels compared with nonrelapsed patients. A FC value of 275 &mgr;g/g achieved sensitivity and negative predictive value of 97% and specificity and positive predictive value of 85% in predicting histological relapse. Conclusions: FC seems to be a direct measure of intestinal inflammation and therefore a good marker of the risk of histological relapse in pediatric IBD patients. The application of this test in clinical practice may enable the avoidance of invasive tests as well as targeting treatment.

Early and late failure of tissue-engineered pulmonary valve conduits used for right ventricular outflow tract reconstruction in patients with congenital heart disease

OBJECTIVES To identify factors associated with the surgical outcome in patients undergoing right ventricular outflow tract reconstruction (RVOTR) using decellularized tissue-engineered pulmonary valve conduits (TEPVc) and to study their safety and longevity. METHODS From April 2006 to April 2010, 93 patients underwent either palliative or corrective RVOTR using Matrix P (37) and Matrix P Plus (56) xenogenic decellularized TEPVc (size range 11-27 mm). Median age and weight at operation were 20 (0.16-290) months and 10.15 (2.65-86) kg respectively. Primary and redo surgery occurred in 40 and 60% of cases, respectively. Eighty-eight patients (94.6%) received conduit implantation in the framework of corrective surgery, whereas in 5 (5.4%) a palliative procedure was undertaken. Follow-up was complete in 91% of patients, with a median duration of 12 months (range: 2 days-51 months). Data analysis included diagnosis, type of surgery (palliative vs. corrective) and age at surgery. Predetermined primary outcomes were represented by conduit failure or dysfunction. RESULTS Two patients with Matrix P and two with Matrix P Plus died in the early post-operatively phase (4.3%). None of the deaths were conduit-related. One patient died at conduit replacement. Thirty-three patients (35.5%) experienced conduit failure whereas conduit dysfunction occurred in 27 patients (29%). Two-year freedom from conduit failure and dysfunction was 60.2% (95% CI: 50.1-69.6) and 77.4% (95% CI: 67.9-84.7), respectively. Reasons for failure were conduit stenosis in 20 cases (61%), pseudoaneurysm in 3 (9%), conduit dilatation (>50% of original diameter) in 2 (6%), stenosis of distal anastomosis involving pulmonary bifurcation in 6 (18%) and allograft dissection in 2 (6%). Histological examination showed inflammatory giant-type cells in the presence of a poor autologous cell seeding in all explanted specimens. Univariate and multivariate analyses showed an association between age at surgery ≤1 year and conduit dysfunction (adjusted HR: 2.29; 95% CI: 1.01-5.20, P = 0.04). CONCLUSIONS Compared with the other conduit for RVOTR Matrix conduits showed a high incidence of failure. Our results suggest that the use of Matrix conduits for RVOTR should be considered with caution.

The Expression of CD90/Thy-1 in Hepatocellular Carcinoma: An In Vivo and In Vitro Study

Although the CD90 (Thy-1) was proposed as biomarker of several tumors and cancer stem cells, the involvement of this molecule in the progression of hepatocellular carcinoma (HCC) and other less frequent hepatic neoplasms is still undefined. The distribution of CD90 was investigated both in in vivo (human tissues samples) and in vitro (human HCC cell line JHH-6). A total of 67 liver tumors were analyzed: 51 HCC, 6 cholangiocarcinoma and 10 hepatoblastoma. In all cases, paired tissue sample of both the tumor and cirrhotic liver was available. Hepatic tissue obtained in 12 healthy livers was used as control. CD90 gene expression was studied by RT-qPCR, protein expression was assessed by quantitative Western Blot, immunofluorescence and flow cytometry. The CD90 expression analysis showed a significant increment in tumor compared to both its paired cirrhotic tissue and normal liver (p<0.05 and p<0.001, respectively). This increase was accompanied by the up-regulation of stromal component in the cancer, as demonstrated by alpha smooth muscle actin staining. In vitro analysis of JHH-6 cell line showed a higher proliferation capacity of CD90+ compared to CD90- cells (p<0.001), also noticed in 3D clonogenic assay (p<0.05), associated by a significant higher expression of the promoting factors (hepatocyte growth factor, fibroblast associated protein and alpha smooth muscle actin 2). A higher expression of the breast cancer resistance protein was found in CD90+ subpopulation while the multidrug resistance protein 1 showed an opposite behavior. Collectively, these results point to the importance of CD90 in the HCC.

Preemptive liver transplantation in a child with familial hypercholesterolemia

Maiorana A, Nobili V, Calandra S, Francalanci P, Bernabei S, El Hachem M, Monti L, Gennari F, Torre G, de Ville de Goyet J, Bartuli A. Preemptive liver transplantation in a child with familial hypercholesterolemia.
Pediatr Transplantation 2011: 15:E25–E29.

Eosinophilic Esophagitis and Barrett’s Esophagus: An Occasional Association or an Overlap Disease?

Background: Esophageal diseases are common in infants and children, and may present with several clinical and pathological aspects. Eosinophilic esophagitis (EE) is characterized by inflammatory, predominantly eosinophilic infiltrate (≧15 eosinophils per high-power field (HPF)) that is not responsive to acid suppression therapy. An immunoallergic pathogenesis has been hypothesized, likely related to food allergy. Barrett’s esophagus (BE) is due to chronic gastroesophageal reflux. The pathological consequence is the replacement of normal stratified squamous epithelium by columnar mucosa with goblet cells. Methods: We present 2 children with a history of food allergy. Endoscopy revealed linear furrows and yellow plaques in the mid-distal esophagus. Results: In both patients histology showed a high number of eosinophils (>30 at HPF) in the mid-distal esophagus and intestinal metaplasia with goblet cells in distal esophagus. Diagnosis of EE associated to BE was made. Restriction diet was administered to treat EE whereas, in 1 case, laparoscopic fundoplication was performed to treat BE. Follow-up showed a remission of endoscopic and histological aspects. Conclusions: The unusual, possibly fortuitous association of EE and BE, two conditions differing in etiopathogenesis, clinical and pathological features, calls for a correct diagnosis to offer suitable treatment and prognosis.

Diagnostic Work-up of Inflammatory Bowel Disease in Children: The Role of Calprotectin Assay

Background: Some reports highlight the potential application of fecal calprotectin as a direct biomarker of intestinal inflammation and, therefore, as support in choosing candidates for endoscopy. The value of 100 &mgr;g/g was recently assumed as the best cutoff for this assay. The purpose of this study was to assess the diagnostic precision of the fecal calprotectin assay, compared to histology, as a stool‐screening biomarker for inflammatory bowel disease (IBD) among a group of prospectively identified patients referred for recurrent abdominal pain and altered bowel habits. Methods: Between 1999 and 2007 we prospectively evaluated the calprotectin assay in a cohort of patients with recurrent abdominal pain and altered bowel habits associated or not with other symptoms suggestive of IBD. All patients suspected of IBD, according to Rome and Porto criteria, provided stool specimens for the calprotectin assay and subsequently underwent endoscopic procedures. Results: Compared to histology, the cutoff of 100 &mgr;g/g reached a sensitivity and specificity of 100% and 68%, respectively, and a likelihood ratio (LR) of 3.1. The cutoff value of 160 &mgr;g/g, however, in our series produced the best joint estimate of sensitivity and specificity: 100% and 80%, respectively, with an LR of 5. Conclusions: In pediatric patients with recurrent abdominal pain and changes in stool habits, a positive calprotectin assay is closely associated with IBD; its systematic employment, therefore, seems to improve the process of endoscopy referral. This test, simple and inexpensive, could be included in the first noninvasive phase of an IBD diagnostic work‐up. (Inflamm Bowel Dis 2010)

Gene and functional up-regulation of the BCRP/ABCG2 transporter in hepatocellular carcinoma.

BackgroundThe Breast Cancer Resistance Protein (BCRP/ABCG2) is one member of ABC transporters proteins super family responsible of drug resistance. Since data on ABCG2 expression in liver malignances are scanty, here we report the expression of ABCG2 in adult human hepatocellular carcinoma (HCC) in both in vivo and in vitro models with different degree of malignancy.MethodsIn cell lines derived from human hepatocellular carcinoma, ABCG2 gene expression was assessed by reverse transcription quantitative real time PCR and function by Hoechst 33342 efflux assay; protein content was assessed by SDS-PAGE Western blot.ResultsABCG2 expression was found to be highest in the most undifferentiated cell lines, and this was related with a higher functional activity. ABCG2 expression was sensitive to antineoplastic drugs since exposure to 5 μM doxorubicin for 24 hours resulted in significant up-regulations of ABCG2 in all cell lines, particularly in those lines with low basal ABCG2 expression (p<0.01). The gene expression was also investigated in 51 adult liver tissues with HCC and related cirrhosis; normal liver tissue was used as control. ABCG2 gene expression was higher in HCC than both cirrhotic paired tissue and normal tissue. This up-regulation was greater (p<0.05) in pathological poorly differentiated grade G3/G4 than in well-differentiated G1/G2 HCC.ConclusionsOur results suggest a correlation of ABCG2 gene expression and differentiation stage both in human and HCC derived cell lines. The rapid up-regulation of ABCG2 to exposure to doxorubicin emphasizes the importance of this transporter in accounting for drug resistance in liver tumors.

Autoimmune hepatitis type 2 following anti-papillomavirus vaccination in a 11-year-old girl

In the last years numerous reports describing a possible association between administration of vaccines and development of autoimmune phenomena and overt autoimmune disease were published. Possible mechanisms of induction of autoimmune phenomena by vaccines and their excipients are probably similar to those implicated in induction by infectious agents. Here we report the case of an 11-year-old girl who developed autoimmune hepatitis type II after four weeks from vaccination against human papillomavirus. The possible relationships between the use of adjuvated vaccine against papillomavirus and autoimmune hepatitis are discussed. Although we do not provide evidence for a causal link, we suggest that the occurrence of the autoimmune hepatitis may be related to the stimulation of immune system by adjuvated-vaccine, that could have triggered the disease in a genetically predisposed individual. Therefore a monitoring of liver function test following administration of vaccine against papillomavirus may be useful in adolescent girl with signs of hepatopathy, as jaundice, dark urine or hepatomegaly, to early identify and to promptly treat autoimmune liver disorders.