Mesenchymal stem cells from Shwachman-Diamond syndrome patients display normal functions and do not contribute to hematological defects.

Shwachman-Diamond syndrome (SDS) is a rare inherited disorder characterized by bone marrow (BM) dysfunction and exocrine pancreatic insufficiency. SDS patients have an increased risk for myelodisplastic syndrome and acute myeloid leukemia. Mesenchymal stem cells (MSCs) are the key component of the hematopoietic microenvironment and are relevant in inducing genetic mutations leading to leukemia. However, their role in SDS is still unexplored. We demonstrated that morphology, growth kinetics and expression of surface markers of MSCs from SDS patients (SDS-MSCs) were similar to normal MSCs. Moreover, SDS-MSCs were able to differentiate into mesengenic lineages and to inhibit the proliferation of mitogen-activated lymphocytes. We demonstrated in an in vitro coculture system that SDS-MSCs, significantly inhibited neutrophil apoptosis probably through interleukin-6 production. In a long-term coculture with CD34(+)-sorted cells, SDS-MSCs were able to sustain CD34(+) cells survival and to preserve their stemness. Finally, SDS-MSCs had normal karyotype and did not show any chromosomal abnormality observed in the hematological components of the BM of SDS patients. Despite their pivotal role in the hematopoietic stem cell niche, our data suggest that MSC themselves do not seem to be responsible for the hematological defects typical of SDS patients.

Shwachman-Diamond syndrome.

Shwachman-Diamond syndrome (SDS) is a rare autosomal recessive disorder with exocrine pancreatic insufficiency, bone marrow failure and skeletal abnormalities. Patients frequently present failure to thrive, susceptibility to infections and short stature. A persistent or intermittent neutropenia occurs in 88-100% of patients. Bone marrow biopsy usually reveals a hypoplastic specimen with varying degrees of hypoplasia and fat infiltration. Some patients may develop myeloblastic syndrome and acute myeloblastic leukemia. The genetic defect in SDS has been identified in 2002. The osteoporosis is increased in patients with SDS, and also, bone malformations are included among the primary characteristics of the syndrome. The severity and location change with age and sexes. The typical characteristics include the following: secondary ossification centers delayed appearance, metaphysis enlargement and irregularity (very common in childhood, particularly in coastal and femur), growth cartilage progressive thinning and irregularity (possibly asymmetric growth), generalized osteopenia with cortical thinning. We describe a clinical case regarding an SDS patient with severe bone abnormalities and treated surgically for corrective osteotomy. The persistent or intermittent neutropenia that characterized this disease and the consequent risk of infection is a contraindication for short stature correction and limbs lengthening.

Celiac disease and obesity: need for nutritional follow-up after diagnosis.

More than 20 years of serological approach to diagnosis of celiac disease (CD) has deeply changed the classical clinical presentation of the disease, and some reports indicate that CD and obesity can coexist in both childhood and adolescence. We reviewed clinical records of 149 children with CD followed in our institution between 1991 and 2007, considering weight, height and body mass index (BMI), both at diagnosis and after at least 12 months of gluten-free diet (GFD). In all, 11% of patients had BMI z-score >+1 and 3% were obese (z-score >+2) at presentation. In our population, there was a significant (P=0.008) increase in BMI z-score after GFD and the percentage of overweight (z-score >+1) subjects almost doubled (11 vs 21%, P=0.03). Our data suggest the need for a careful follow-up of nutritional status after diagnosis of CD, especially addressing those who are already overweight at presentation.

The isochromosome i(7)(q10) carrying c.258+2t>c mutation of the SBDS gene does not promote development of myeloid malignancies in patients with Shwachman syndrome.

Shwachman-Diamond syndrome (SDS) is an autosomal recessive disorder, characterized by exocrine pancreatic insufficiency, skeletal abnormalities and bone marrow (BM) dysfunction with an increased risk to develop myelodysplastic syndrome and/or acute myeloid leukaemia (MDS/AML). SDS is caused, in nearly 90% of cases, by two common mutations (that is, c.183_184TA>CT and c.258+2T>C) in exon 2 of the SBDS gene, localized on chromosome 7. Clonal chromosome anomalies are often found in the BM of SDS patients; the most frequent is an isochromosome for long arms of chromosome 7, i(7)(q10). We studied eight patients with SDS carrying the i(7)(q10) who were compound heterozygotes for SBDS mutations. By assessing the parental origin of the i(7)(q10) using microsatellite analysis, we inferred from the results which mutation was present in double dose in the isochromosome. We demonstrate that in all cases the i(7)(q10) carries a double dose of the c.258+2T>C, and we suggest that, as the c.258+2T>C mutation still allows the production of some amount of normal protein, this may contribute to the low incidence of MDS/AML in this subset of SDS patients.

Long-term azithromycin in cystic fibrosis: another possible mechanism of action?

Azithromycin is used for the treatment of cystic fibrosis lung disease, although its mechanisms of action are not completely understood. Besides its antiinflammatory and antimicrobial activities, one possibility could be the overexpression induction of the multidrug resistance-associated protein (MRP), which could affect chloride transport, thus overcoming the ion transport defect of cystic fibrosis. Seven patients were evaluated before and after 4 weeks of azithromycin treatment (500 mg once daily). Ion transport was studied in vivo by measuring nasal potential difference (NPD). MRP mRNA expression was studied in nasal cells by an internal standard-based semiquantitative RT-PCR assay. NPD was consistent with cystic fibrosis before treatment. After azithromycin treatment, sodium transport was still impaired, whereas a significant increase in chloride conductance was observed (p = 0.03). A significant direct correlation was found between MRP mRNA expression levels and NPD chloride response after azithromycin treatment (p = 0.04, r = 0.78). In conclusion, azithromycin may induce MRP overexpression and restore chloride conductance in the airways of cystic fibrosis patients. These findings suggest a new potential role of azithromycin in the treatment of cystic fibrosis pulmonary disease, i.e. the possibility to upregulate proteins whose function may, at least in part, compensate for the basic defect of cystic fibrosis.

Gluten sensitivity and 'normal' histology: is the intestinal mucosa really normal?

BACKGROUND: Early pathogenetic events of gluten intolerance may be overlooked in patients with serologic markers of celiac disease and normal intestinal mucosa by both conventional histology and immunohistochemistry. AIMS: To investigate if a submicroscopical damage of the absorptive cell surface was associated with developing gluten sensitivity. PATIENTS AND METHODS: Duodenal biopsies of seven subjects with positive anti-endomysial antibodies and normal histology underwent ultrastructural evaluation of the epithelial surface by means of both scanning and transmission electron microscopy. Specimens of intestinal mucosa of 14 children with non-celiac conditions were used as controls. RESULTS: In four patients, electron microscopy revealed alterations of the enterocyte brush border with a significant reduction of the height of microvilli. After several months, three of them had a second biopsy that eventually showed histological modifications suggestive of celiac disease. In the other three patients, no significant alteration of enterocyte ultrastructure was observed. One of them, rebiopsied after 12 months, still showed a normal duodenal histology. CONCLUSIONS: Gluten sensitivity can be associated with 'minimal' mucosal changes not detectable with conventional light microscopy. Such lesions, which primarily involve microvillous structure, may imply a reduction of intestinal absorptive surface already in the latent stage of the disease.

[Latent celiac disease in subjects with serum anti-endomysial antibodies and normal intestinal biopsy]. / Celiachia latente in soggetti con anticorpi antiendomisio positivi e biopsia intestinale normale.

OBJECTIVES: Data on the follow-up of a group of subjects with serum antiendomysial antibodies (EMA) and normal mucosal architecture at the intestinal biopsy are reported. Clinical problems concerning possible evolution of potential celiac disease (CD) towards gluten-induced histological damage are discussed. METHODS: Eleven patients belonging to high-risk groups for CD (5 with type-1 diabetes, 2 with familiarity for CD and 4 with symptoms suggesting CD) who had a normal intestinal biopsy, despite positive antiendomysial test, were followed-up. Antigliadin and antitransglutaminase antibodies (anti-tTG) and HLA genotyping were also assessed. According to clinical and serological data a second biopsy was performed in six of them. RESULTS: At the time of the first normal biopsy, all patients were positive for EMA and 5/8 for anti-tTG. Five of 6 subjects genotyped were HLA-DQ2+ or DQ8+. Six patients were rebiopsed after 1 to 4 years. Three had mucosal atrophy, 1 had mild increase of intraepithelial lymphocytes and 2 were morphologically normal. CONCLUSIONS: Subjects with antiendomysial antibodies and normal intestinal biopsy deserve clinical and serological follow-up to reduce the time of possible latency of CD. Although good predictors of progression of the disease are not still available, antiendomysial antibodies assessment and HLA genotyping may help to suggest individuals at higher risk to develop gluten-induced enteropathy. This study confirms that subjects with persistent signs of gluten sensitivity and normal biopsy should be re-examined.

Shwachman-Diamond syndrome: clinical phenotypes.

The clinical phenotype of Shwachman-Diamond syndrome (SDS) is extremely heterogeneous, showing a wide range of abnormalities and symptoms. The main characteristics of the syndrome are exocrine pancreatic dysfunction, haematologic abnormality and growth retardation. At diagnosis, especially when made in infancy, symptoms of pancreatic insufficiency are always present. This condition could be considered as a transient pancreatic insufficiency. In fact, several studies have shown that, with advancing age, about 40-60% of patients become pancreatic sufficient. Observations on the evolution of pancreatic activity lead us to believe that the diagnosis of SDS must be considered even in the absence of signs and symptoms of pancreatic insufficiency. Intermittent neutropenia is the most common haematological finding in SDS, but more of the bone marrow cellular elements can be involved. In recent years, recombinant human granulocyte colony-stimulating factor has been used in some SDS subjects with severe neutropenia and frequent infection. The major haematological problem in the disease is the appearance of acute myeloid leukaemia; however, its prevalence is difficult to establish. Growth retardation is a typical manifestation. Weight and length are deficient at birth and remain below normal over time. Some studies show that SDS patients present short stature rather than malnutrition and this would suggest an inherent growth problem. A broad spectrum of skeletal abnormalities has been found to be associated with this syndrome. Short ribs with broadened anterior ends and metaphyseal dyschondroplasia of the long bone are the most common findings. Elevated liver enzymes and hepatomegaly are present in the first years of life with subsequent improvement without complications. Developmental delay, learning disorders and attention deficit disorders are also reported.

Shwachman's syndrome: pathomorphosis and long-term outcome.

BACKGROUND: Shwachman's syndrome is the second most common cause of inherited/congenital pancreatic insufficiency after cystic fibrosis. The main associated features are usually cyclic neutropenia, metaphyseal dysostosis, and growth retardation. Other organs or functions may be involved in this syndrome, showing a wide range of abnormalities and symptoms. There are reports of Shwachman's syndrome in childhood, but little is known about the long-term clinical course of these patients. This article reports on the pathomorphosis and long-term follow-up of 13 patients with Shwachman's syndrome diagnosed in infancy focusing, in particular, on modifications of the exocrine pancreatic function over time. METHODS: Exocrine pancreatic function was evaluated by duodenal intubation followed by a pancreatic stimulation test. Nutritional, biochemical, hematologic, radiologic, and psychological evaluations were performed at various intervals. Six patients were included in long-term follow-up evaluation. RESULTS: At diagnosis, growth retardation was present in all patients, and all subjects showed pancreatic insufficiency. Hematologic features (intermittent neutropenia, anemia and thrombocytopenia), respiratory infection during the first years of life, and skeletal abnormalities were also frequently observed. Other associated features at diagnosis included hepatic involvement and occasional renal dysfunction. In the six patients followed up, a significant growth improvement was observed. In five of them the pancreatic stimulation test showed values of lipase within reference range outputs, whereas fat balance or fecal fat losses were normal in all but one subject. Of seven subjects assessed by psychological evaluation, IQ test results were markedly abnormal in one and bordered on abnormality in the others. CONCLUSIONS: The present data on Shwachman's syndrome diagnosed in infancy underline the possibility of improvement or normalization of exocrine pancreatic function with age, suggesting the need for periodic checks on pancreatic activity in these subjects. It also indicates the possibility of diagnosis of this syndrome in the absence of pancreatic insufficiency; decreasing frequency of infections over time; and the usefulness of early neuropsychological evaluation.

Bronchial artery embolization in the management of hemoptysis in cystic fibrosis.

Massive hemoptysis and/or recurrent expectoration of measurable amounts of blood are common complications of chronic bronchopulmonary infections in cystic fibrosis (CF). When conservative treatment fails to control bleeding, surgery or bronchial artery embolization (BAE) is frequently considered. We present our experience and long-term follow up of BAE in 14 CF patients (age range 15-39 years) with massive (6 subjects) and/or recurrent (8 subjects) hemoptysis not responsive to medical treatment. Seven had chronic hypercapnic respiratory failure. After angiographic evaluation, polyvinyl alcohol particles (Ivalon) were injected to embolize obviously enlarged bronchial arteries. Seventeen procedures were performed in 14 patients and 36 bronchial arteries were embolized. All the patients stopped bleeding immediately upon BAE. Most of the patients had postembolization fever, dysphagia, and transient chest pain which were managed symptomatically. After a median follow-up period of 10.5 months (range 0.5-38 months), no recurrence of hemoptysis was observed in 8 patients who are still alive. In 3 patients hemoptysis recurred and they underwent reembolization after 3, 22, and 25 months, respectively. Three subjects died of respiratory failure within 5 months from BAE. Presently, 50% of patients studied had a > or = 1 year interval free of major hemoptysis after the first BAE. Our experience indicates that massive and/or recurrent hemoptysis in CF patients can be safety and effectively managed by BAE if the procedure is performed by a skilled practitioner. The procedure was well tolerated and resulted in prolonged and satisfactory bleeding control in most patients.

Portal hypertension and esophageal varices in cystic fibrosis. Unreliability of echo-Doppler flowmetry.

To investigate the role of echo-Doppler flowmetry in evaluating patients with cystic fibrosis and portal hypertension at risk of esophageal varices, we studied 26 subjects divided in 3 groups: 9 with portal hypertension and esophageal varices, 8 with chronic liver disease without varices, and 9 without chronic liver disease. Spleen size, diameter, blood velocity, and flow rate of portal, splenic, and superior mesenteric veins were recorded. In patients without chronic liver disease Doppler measurements were repeated on 2 different days to assess intraobserver variability. Significant differences among the three groups were found for mean values of spleen size and diameters of portal, splenic, and superior mesenteric veins. Nevertheless, a considerable overlapping of individual data was observed. No differences were observed in mean hemodynamic measurements, except for blood velocity in portal vein and flow rate in splenic vein. The intraobserver variability for repeated Doppler measurements was clinically unacceptable for most of the variables studied. Echo-Doppler assessment of splanchnic flow seems to be an unreliable tool in the management of cystic fibrosis patients with portal hypertension at risk of esophageal varices.

Ear disease is not a common complication in cystic fibrosis.

Although upper respiratory tract involvement is a common finding in cystic fibrosis (CF), there is no agreement on whether hearing is affected in these patients. We studied 75 CF subjects and 50 healthy age-matched children with the same audiological protocol. An original scoring system was used to quantify the degree of hearing involvement (normal, mild, moderate and severe) in each subject. Prevalence of ear involvement in children with CF was similar to that in age-matched control subjects (25.4% and 18% respectively, P > 0.05). Ear disease in CF was not related to pulmonary disease, radiological sinusitis, nasal polyposis, or use of parenteral aminoglycosides. These data showed that the risk of ear disease in CF was not increased even if patients with severe audiological involvement were described only in the CF group.

[Neutrophil chemotaxis. II. Clinical implications and therapeutic indications in children]. / La chemiotassi del neutrofilo. II. Implicazioni cliniche e cenni di terapia in età pediatrica.

Defects of neutrophil chemotaxis are usually accompanied by recurrent or chronic infections of the skin and the respiratory tract. The onset of clinical symptoms may occur early in infancy; infections tend to be severe and they are generally due by organisms which are of relatively low pathogenicity in the healthy subject. Abnormalities of neutrophil chemotaxis were classified and described as humoral, cellular and unclassified defects. The relevance of neutrophil chemotaxis in the single clinical entities was discussed, taking in particular account the most recent views on the argument. Some details on practical and theoretical therapeutic approaches were also reviewed.

[Neutrophil chemotaxis. I. Physiology aspects and study methods]. / La chemiotassi del neutrofilo. I. Aspetti di fisiologia e metodi di studio.

Neutrophil chemotaxis is a complex orchestration of biochemical and morphologic events that requires the integrity and coordination of a complicated series of cellular functions. Different substances (both endogenous and exogenous) with chemotactic activity for human neutrophils were described; their interaction with specific receptors on neutrophil cell membrane is requested to induce a directional motility. The ligand-receptor interaction causes the activation of intracellular metabolic pathways and the modification of cytoskeletal structures involved in the chemotactic response. Neutrophil chemotaxis may be studied, for clinical purpose, by in vitro and in vivo methods. The two approaches of investigation are complementary, and, if properly used, they may give a valuable help in defining the nature of the chemotactic defect.

Pulmonary hemosiderosis in a child with cystic fibrosis.

Two episodes of acute iron deficiency anemia with blood-stained sputum and symptoms of severe acute pulmonary exacerbation were observed in a child with cystic fibrosis (CF). Hemosiderin laden macrophages (siderophages) were repeatedly found in sputum and gastric juice, suggesting the coexistence of pulmonary hemosiderosis (PH). The possibility that pulmonary immune-mediated mechanisms characteristic of CF may have played a role in the development of PH is considered.