Sule Unal

LAD-1/variant syndrome is caused by mutations in FERMT3

Leukocyte adhesion deficiency-1/variant (LAD1v) syndrome presents early in life and manifests by infections without pus formation in the presence of a leukocytosis combined with a Glanzmann-type bleeding disorder, resulting from a hematopoietic defect in integrin activation. In 7 consanguineous families, we previously established that this defect was not the result of defective Rap1 activation, as proposed by other investigators. In search of the genetic defect, we carried out homozygosity mapping in 3 of these patients, and a 13-Mb region on chromosome 11 was identified. All 7 LAD1v families share the same haplotype, in which 3 disease-associated sequence variants were identified: a putative splice site mutation in CALDAGGEF1 (encoding an exchange factor for Rap1), an intronic 1.8-kb deletion in NRXN2, and a premature stop codon (p.Arg509X) in FERMT3. Two other LAD1v patients were found to carry different stop codons in FERMT3 (p.Arg573X and p.Trp229X) and lacked the CALDAGGEF1 and NRXN2 mutations, providing convincing evidence that FERMT3 is the gene responsible for LAD1v. FERMT3 encodes kindlin-3 in hematopoietic cells, a protein present together with integrins in focal adhesions. Kindlin-3 protein expression was undetectable in the leukocytes and platelets of all patients tested. These results indicate that the LAD1v syndrome is caused by truncating mutations in FERMT3.

Comparison of primary human cytotoxic T-cell and natural killer cell responses reveal similar molecular requirements for lytic granule exocytosis but differences in cytokine production.

Cytotoxic lymphocytes, encompassing cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells, kill pathogen-infected, neoplastic, or certain hematopoietic cells through the release of perforin-containing lytic granules. In the present study, we first performed probability-state modeling of differentiation and lytic granule markers on CD8(+) T cells to enable the comparison of bona fide CTLs with NK cells. Analysis identified CD57(bright) expression as a reliable phenotype of granule marker-containing CTLs. We then compared CD3(+)CD8(+)CD57(bright) CTLs with NK cells. Healthy adult peripheral blood CD3(+)CD8(+)CD57(bright) CTLs expressed more granzyme B but less perforin than CD3(-)CD56(dim) NK cells. On stimulation, such CTLs degranulated more readily than other T-cell subsets, but had a propensity to degranulate that was similar to NK cells. Remarkably, the CTLs produced cytokines more rapidly and with greater frequency than NK cells. In patients with biallelic mutations in UNC13D, STX11, or STXBP2 associated with familial hemophagocytic lymphohistiocytosis, CTL and NK cell degranulation were similarly impaired. Therefore, cytotoxic lymphocyte subsets have similar requirements for Munc13-4, syntaxin-11, and Munc18-2 in lytic granule exocytosis. The present results provide a detailed comparison of human CD3(+)CD8(+)CD57(bright) CTLs and NK cells and suggest that analysis of CD57(bright) CTL function may prove useful in the diagnosis of primary immunodeficiencies including familial hemophagocytic lymphohistiocytosis.

Value of Dual Energy Computed Tomography for detection of myocardial iron deposition in Thalassaemia patients: Initial experience

PURPOSE The aim of our study was to compare the value of cardiac DECT (cDECT) for detection of myocardial iron deposition to T2*w cardiac MRI (cMRI). MATERIAL AND METHODS Nineteen patients with clinical history of Thalassaemia underwent T2*-weighted cardiac MRI (cMRI) with a 1.5 T MR scanner (MAGNETOM Symphony, Siemens Medical Solutions, Erlangen, Germany) and cardiac dual energy CT (cDECT) with a DSCT scanner (SOMATOM Definition, Siemens Medical Solutions, Erlangen, Germany) on the same day. HU values obtained from cDECT scans and T2*-values from cMRI were statistically correlated to calculate significance levels. Table times were measured for both cDECT and cMRI and compared. Patients were asked to grade their subjective comfort during the examination. RESULTS In all patients cDECT scans were successfully acquired. HU values of septal muscle correlated strongly with T2*-values, whereas no correlation was found for paraspinal muscle. Table time was significantly shorter for cDECT compared to cMRI (mean: 3.7 min vs. 11.2 min) and subjective patient comfort was rated comfortable for cDECT and average to poor for cMRI. Mean radiation dose was 0.71 mSv. CONCLUSION cDECT scans seem to be possible for evaluation of myocardial iron load in pediatric Thalassaemia patients.

Clinical and molecular aspects of Turkish familial hemophagocytic lymphohistiocytosis patients with perforin mutations

The aim of this study was to elucidate the pathologic sequence changes and associated clinical phenotypes in 9 new patients showing homozygosity for perforin gene among a total of 37 (24%) Turkish FHL families studied by linkage analysis. These 9 unrelated patients (5M/4F) were coming from consanguineous families and their presentation ages of systemic symptoms were ranged from birth to 15 years. Direct sequencing of coding exons of the perforin gene led to the identification of five different homozygous alterations. The nonsense W374X mutation was identified in three patients while four different missense mutations namely G149S, V50M, A91V and novel A523D were detected in the rest six patients.

Secondary Hemophagocytosis in 3 Patients With Organic Acidemia Involving Propionate Metabolism

Hemophagocytic lymphohistiocytosis (HLH) may develop secondary to infections, malignancies, immune deficiency syndromes, and rheumatologic and metabolic disorders. Associations between HLH and inborn errors of metabolism, including lysinuric protein intolerance, multiple sulfatase deficiency, galactosemia, Gaucher disease, Pearson syndrome, and galactosialidosis, have previously been reported in the literature. In this report the authors present 3 children with disorders of propionate metabolism—1 with methylmalonic acidemia and 2 with propionic acidemia—who developed secondary HLH during their metabolic attacks. All patients fulfilled the 5 HLH criteria of the Histiocyte Society. Familial HLH was ruled out by molecular analysis. Plasma exchange was performed for 2 of them. Unfortunately 1 died of multiorgan failure despite intensive therapy. This is the first report of such an association.

The glycocalyx and Trauma: A Review

ABSTRACT In the United States trauma is the leading cause of mortality among those under the age of 45, claiming approximately 192,000 lives each year. Significant personal disability, lost productivity, and long-term healthcare needs are common and contribute 580 billion dollars in economic impact each year. Improving resuscitation strategies and the early acute care of trauma patients has the potential to reduce the pathological sequelae of combined exuberant inflammation and immune suppression that can co-exist, or occur temporally, and adversely affect outcomes. The endothelial and epithelial glycocalyx has emerged as an important participant in both inflammation and immunomodulation. Constituents of the glycocalyx have been used as biomarkers of injury severity and have the potential to be target(s) for therapeutic interventions aimed at immune modulation. In this review, we provide a contemporary understanding of the physiologic structure and function of the glycocalyx and its role in traumatic injury with a particular emphasis on lung injury.

Retrospective cohort study of 205 cases with congenital dyserythropoietic anemia type II: Definition of clinical and molecular spectrum and identification of new diagnostic scores

Congenital Dyserythropoietic Anemia II (CDA II) is a rare hyporegenerative anemia of variable degree, whose causative gene is SEC23B. More than 60 causative mutations in 142 independent pedigrees have been described so far. However, the prevalence of the CDA II is probably underestimated, since its clinical spectrum was not yet well‐defined and thus it is often misdiagnosed with more frequent clinically‐related anemias. This study represents the first meta‐analysis on clinical and molecular spectrum of CDA II from the largest cohort of cases ever described. We characterized 41 new cases and 18 mutations not yet associated to CDA II, thus expanding the global series to 205 cases (172 unrelated) and the total number of causative variants to 84. The 68.3% of patients are included in our International Registry of CDA II (Napoli, Italy). A genotype–phenotype correlation in three genotypic groups of patients was assessed. To quantify the degree of severity in each patient, a method based on ranking score was performed. We introduced a clinical index to easily discriminate patients with a well‐compensated hemolytic anemia from those with ineffective erythropoiesis. Finally, the worldwide geographical distribution of SEC23B alleles highlighted the presence of multiple founder effects in different areas of the world. Am. J. Hematol. 89:E169–E175, 2014.

A novel mutation in a family with DNA ligase IV deficiency syndrome

DNA ligase IV deficiency syndrome (LIG4 syndrome) is a rare autosomal recessive disorder characterized by microcephaly, growth retardation, low birth weight, dysmorphic facial findings, immunodeficiency, pancytopenia, and radiosensitivity due to impaired repair of DNA double‐strand breaks by non‐homologous end‐joining. Herein, we report two siblings with LIG4 syndrome with a novel mutation. One of the siblings, who had normocellular marrow, had autologous reconstitution after initial non‐myeloablative conditioning and underwent successful second hematopoietic stem cell transplantation after conditioning with busulfan, cyclophosphamide, and anti‐thymocyte globulin. Our findings indicate that transplantation with myeloablative conditioning can be used successfully in LIG4 syndrome patients. Pediatr Blood Cancer 2009;53:482–484.

Bleeding and non-bleeding phenotypes in patients with GGCX gene mutations.

Functional limitations for the vitamin K cycle, caused either by mutations in gamma-glutamyl carboxylase or vitamin K epoxide reductase genes, result in hereditary deficiency of vitamin K-dependent coagulation factors (VKCFD1 and VKCFD2, respectively). Patients suffering from VKCFD often share several other anatomical irregularities which are not related to haemostasis. Here we report on nine patients, eight of them previously unreported, who presented with VKCFD1. All were examined with special attention to vitamin K-dependent coagulation factors as well as to bone and heart development and to other anatomical signs of embryonal vitamin K deficiency. In total, we detected ten mutations in the gamma-glutamyl carboxylase gene of which seven have not been previously reported. Most interestingly, additional non-bleeding phenotypes were observed in all patients including midfacial hypoplasia, premature osteoporosis, cochlear hearing loss, heart valve defects, pulmonary stenosis, or pseudoxanthoma elasticum-like phenotype. Undercarboxylated matrix Gla protein, osteocalcin, and periostin appear to be responsible for these defects which are also observed in cases of fetal warfarin syndrome.

Observational study comparing long-term safety and efficacy of Deferasirox with Desferrioxamine therapy in chelation-naïve children with transfusional iron overload

Objectives:  An observational study was conducted to explore postmarketing safety and efficacy of Deferasirox (DFX) in comparison with conventional Desferrioxamine (DFO) in chelation‐naïve children with transfusional iron overload.