Efficacy of T-cell assays for the diagnosis of primary defects in cytotoxic lymphocyte exocytosis.

ABSTRACT: Primary hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disorder associated with autosomal recessive variants in genes required for perforin-mediated lymphocyte cytotoxicity. A rapid diagnosis is crucial for successful treatment. Although defective cytotoxic T lymphocyte (CTL) function causes pathogenesis, quantification of natural killer (NK)-cell exocytosis triggered by K562 target cells currently represents a standard diagnostic procedure for primary HLH. We have prospectively evaluated different lymphocyte exocytosis assays in 213 patients referred for evaluation for suspected HLH and related hyperinflammatory syndromes. A total of 138 patients received a molecular diagnosis consistent with primary HLH. Assessment of Fc receptor-triggered NK-cell and T-cell receptor (TCR)-triggered CTL exocytosis displayed higher sensitivity and improved specificity for the diagnosis of primary HLH than routine K562 cell-based assays, with these assays combined providing a sensitivity of 100% and specificity of 98.3%. By comparison, NK-cell exocytosis after K562 target cell stimulation displayed a higher interindividual variability, in part explained by differences in NK-cell differentiation or large functional reductions after shipment. We thus recommend combined analysis of TCR-triggered CTL and Fc receptor-triggered NK-cell exocytosis for the diagnosis of patients with suspected familial HLH or atypical manifestations of congenital defects in lymphocyte exocytosis.

Nutritional Status of Pediatric Patients With Acute Lymphoblastic Leukemia Under Chemotherapy: A Pilot Longitudinal Study.

BACKGROUND: The study investigates the nutritional status in children with acute lymphoblastic leukemia (ALL) during chemotherapy treatment because nourishment is substantial, as much as chemotherapy in children with malignant diseases. MATERIAL AND METHOD: We enrolled 17 children with ALL (between 1 to 16 year-old, mean age 6.03 ± 4.04 y) from 5 different centers in Istanbul between September 2013 and May 2014. Anthropometric data, prealbumin, B12, and folate levels were assessed, at diagnosis, after the induction phase of chemotherapy, and before maintenance phases of chemotherapy in a longitudinal and prospective study. RESULTS: Patients remarkably lost weight at the end of the induction phase ( P =0.064) and regained this loss before maintenance chemotherapy ( P =0.001). At the end of induction chemotherapy serum prealbumin level ( P =0.002), weight for height ratios ( P =0.016), weight for age ratios ( P =0.019) significantly decreased. From the end of the induction phase to the beginning of maintenance chemotherapy, weight ( P =0.001) and weight for age ( P =0.017) significantly, and weight for height were remarkably elevated ( P =0.076). At the end of the induction phase, serum prealbumin levels were significantly lower ( P =0.048) and below laboratory reference values ( P =0.009) in children younger than 60 months compared with those older. Serum folate levels increased from the end of the induction phase to the beginning of the maintenance phase ( P =0.025). Serum vitamin B12 levels did not alter significantly. CONCLUSION: There is malnutrition risk at the end of the induction phase of the ALL-BFM chemotherapy regimen; therefore, clinicians should follow up on nutrition closely, especially in under 5-year-old patients. However, before the beginning of the maintenance phase, children start to gain weight, and obesity risk occurs. Thus , further studies are needed to evaluate nutritional status during childhood ALL chemotherapy.

The Role of Anti-Neutrophil Antibodies in the Etiologic Classification of Childhood Neutropenia: A Cross-Sectional Study in a Tertiary Center.

Infections, drugs, malignancies, immunodeficiency, and autoimmunity may cause neutropenia. In primary autoimmune neutropenia, anti-neutrophil antibodies (ANeuA) bind to membrane antigens of neutrophils, which give rise to peripheral destruction of neutrophils. However, it is not always easy to detect these antibodies. This study aims to investigate the etiology of neutropenia, and at the same time to evaluate the immune mechanisms by ANeuA testing using granulocyte indirect immunofluorescence test. In our study, 310 neutropenic patients who were between 3 months and 18 years of age were evaluated. ANeuA screening tests were performed in 108 neutropenic patients (group 1), and these patients were divided into 2 subgroups as persistent neutropenia (group 1P, n=12) and recovered neutropenia (group 1R, n=96). Besides, a control group in the same age range was formed, consisting of 39 non-neutropenic children (group 2). ANeuA serum levels were also checked in these groups, and no statistically significant difference could be found between groups 1 and 2, or between groups 1P and 1R, regarding ANeuA levels. As a conclusion, our study was the first comprehensive research in Turkey investigating the large-scale etiology of neutropenia. Moreover, while ANeuA screening tests did not provide sufficient insight for immune neutropenia, we argue that it is not necessary for routine use and that further research in the etiology of neutropenia is required.

ILC3 deficiency and generalized ILC abnormalities in DOCK8-deficient patients.

BACKGROUND: Dedicator of cytokinesis 8 (DOCK8) deficiency is the main cause of the autosomal recessive hyper-IgE syndrome (HIES). We previously reported the selective loss of group 3 innate lymphoid cell (ILC) number and function in a Dock8-deficient mouse model. In this study, we sought to test whether DOCK8 is required for the function and maintenance of ILC subsets in humans. METHODS: Peripheral blood ILC1-3 subsets of 16 DOCK8-deficient patients recruited at the pretransplant stage, and seven patients with autosomal dominant (AD) HIES due to STAT3 mutations, were compared with those of healthy controls or post-transplant DOCK8-deficient patients (n = 12) by flow cytometry and real-time qPCR. Sorted total ILCs from DOCK8- or STAT3-mutant patients and healthy controls were assayed for survival, apoptosis, proliferation, and activation by IL-7, IL-23, and IL-12 by cell culture, flow cytometry, and phospho-flow assays. RESULTS: DOCK8-deficient but not STAT3-mutant patients exhibited a profound depletion of ILC3s, and to a lesser extent ILC2s, in their peripheral blood. DOCK8-deficient ILC1-3 subsets had defective proliferation, expressed lower levels of IL-7R, responded less to IL-7, IL-12, or IL-23 cytokines, and were more prone to apoptosis compared with those of healthy controls. CONCLUSION: DOCK8 regulates human ILC3 expansion and survival, and more globally ILC cytokine signaling and proliferation. DOCK8 deficiency leads to loss of ILC3 from peripheral blood. ILC3 deficiency may contribute to the susceptibility of DOCK8-deficient patients to infections.

Asymptomatic intracranial hemorrhage in a newborn with congenital factor VII deficiency and successful treatment with recombinant activated factor VII.

Ince Z, Bulut Ö, Tugrul-Aksakal M, Ünüvar A, Devecioglu Ö, Çoban A. Asymptomatic intracranial hemorrhage in a newborn with congenital factor VII deficiency and successful treatment with recombinant activated factor VII. Turk J Pediatr 2018; 60: 562-565. Intracranial hemorrhage is considered the most common cause of death in newborns with congenital factor VII (FVII) deficiency. Recombinant activated FVII (rFVIIa) provides specific replacement therapy, however there is limited experience with its neonatal use. We describe our experience about the treatment of intracranial hemorrhage in a newborn with congenital FVII deficiency and emphasize the importance of imaging in asymptomatic patients. She presented with ecchymoses on her skin, no other pathological clinical signs, prolonged PT, normal PTT and FVII activity of 2%. Intracranial hemorrhage was diagnosed while screening for internal bleedings. Treatment with rFVIIa resulted in stabilization and regression of the hematoma.

Targeted high-throughput sequencing for genetic diagnostics of hemophagocytic lymphohistiocytosis.

BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) is a rapid-onset, potentially fatal hyperinflammatory syndrome. A prompt molecular diagnosis is crucial for appropriate clinical management. Here, we validated and prospectively evaluated a targeted high-throughput sequencing approach for HLH diagnostics. METHODS: A high-throughput sequencing strategy of 12 genes linked to HLH was validated in 13 patients with previously identified HLH-associated mutations and prospectively evaluated in 58 HLH patients. Moreover, 2504 healthy individuals from the 1000 Genomes project were analyzed in silico for variants in the same genes. RESULTS: Analyses revealed a mutation detection sensitivity of 97.3%, an average coverage per gene of 98.0%, and adequate coverage over 98.6% of sites previously reported as mutated in these genes. In the prospective cohort, we achieved a diagnosis in 22 out of 58 patients (38%). Genetically undiagnosed HLH patients had a later age at onset and manifested higher frequencies of known secondary HLH triggers. Rare, putatively pathogenic monoallelic variants were identified in nine patients. However, such monoallelic variants were not enriched compared with healthy individuals. CONCLUSIONS: We have established a comprehensive high-throughput platform for genetic screening of patients with HLH. Almost all cases with reduced natural killer cell function received a diagnosis, but the majority of the prospective cases remain genetically unexplained, highlighting genetic heterogeneity and environmental impact within HLH. Moreover, in silico analyses of the genetic variation affecting HLH-related genes in the general population suggest caution with respect to interpreting causality between monoallelic mutations and HLH. A complete understanding of the genetic susceptibility to HLH thus requires further in-depth investigations, including genome sequencing and detailed immunological characterization.

Evaluation of Alpha-Thalassemia Mutations in Cases with Hypochromic Microcytic Anemia: The Istanbul Perspective.

OBJECTIVE: Alpha thalassemia syndromes are caused by mutations on one or more of the four α-globin genes. Mutations could be either more commonly deletional or non-deletional. As some deletions (3.7 and 4.2) cause α+-thalassemia, some cause (-20.5, MED, THAI, FIL) α0 -thalassemia. The aim of this study was to determine alpha thalassemia mutations in patients with unsolved hypochromic microcytic anemia and to evaluate types of mutations. MATERIAL AND METHODS: Two hundred six patients with hypochromic microcytic anemia were evaluated for alpha thalassemia. A venous blood sample of 2 mL was drawn from each patient for DNA isolation. The samples were investigated for α-thalassemia mutations by using the Vienna Lab α-Globlin StripAssay TM commercial kit. RESULTS: Fourteen different mutations were determined in 95 (46.1%) patients. The most common mutation was the 3.7 single gene deletion and was found in 37 patients (n=37/95, 39%). Others common mutations were the 20.5 kb double gene deletion (n=20 patients, 21%), MED double gene deletion (n=17 patients, 17.9%), α2 IVS1 (n=10 patients, 10.5%), α2 cd142 Hb Koya Dora (n=6 patients, 6.3%), α2 polyA1 (Saudi type) (n=6 patients, 6.3%), 4.2 single gene deletion (n=4 patients, 4.2%), α1 cd14 (n=2 patients, 2.1%), and -FIL mutation (n=2 patients 2.1%), respectively. Hb Adana, Hb Icaria, α2 init cd and α2 polyA2 (Turkish type) were found in 1% of the patients (n=1). Seven patients (7.4%) had α-thalassemia triplication. In our study, three mutations (Hb Icaria, α1 cd14, α2 init.cd) were determined firstly in Turkey. Seven mutations (-SEA, -THAI, Hb Constant Spring, α2 cd19, α2 cd59, α2 cd125, Hb Paksé) were not determined in this study. CONCLUSION: Alpha thalassemia should be considered in the differential diagnosis of hypochromic microcytic anemia especially in cases without iron deficiency and b-thalassemia carrier state. Genetic testing should be performed for the suspicious cases. We also recommend that a national database with all mutations in Turkey should be created to screen the alpha thalassemia cost-effectively.

Outcome in neuroblastoma.

OBJECTIVE: To determine outcome of neuroblastoma (NBL) in children under 18 mo of age who had been treated with national protocols. METHODS: The characteristics and treatment outcomes of 27 children were evaluated retrospectively. RESULTS: The event-free survival (EFS) at 60 and 108 mo were 84.7 % ± 7.7 and 72.6 % ± 7.7, respectively. The overall survival (OS) was 91.7 % ± 8 at 108 mo. The only significant risk factor for OS in children with neuroblastoma was the treatment response at the end of therapy (p = 0.001). "Wait and see" policy was applied to two infants with low risk NBL and one infant with stage 4S neuroblastoma and all 3 of these infants have been in remission at last followup. Four of the five patients with MYCN-amplified neuroblastoma were alive at a median follow-up time of 54 mo (range: 5-108 mo). CONCLUSIONS: The EFS and OS of the present group were similar to that of the previous series which included children under 18 mo of age with neuroblastoma. Well known prognostic factors did not affect EFS and OS significantly; this may be related to the retrospective design of the present study and the small number of patients reviewed. High survival rate in infants with MYCN-amplified tumors suggests the difference in the biology of infant neuroblastoma.

A disease difficult to diagnose: Gardner-Diamond syndrome accompanied by platelet dysfunction.

Gardner Diamond syndrome is a rare condition characterized with painful ecchymoses in different parts of the body and cutaneous and mucosal hemorrhages. The etiology is not known fully and psychogenic factors are thought to be involved. Cutaneous lesions and hemorrhages develop mostly following emotional stress and rarely minor traumas and may recur. Although the extremities are involved with the highest rate, the lesions may be observed in any part of the body. Hemostatic tests are generally normal. The majority of the subjects is composed of young women. It is observed more rarely in men and children. In this article, a patient who presented with recurring painful echymoses and bleeding disorder and diagnosed with Gardner Diamond syndrome by intracutaneous injection of autologous blood was presented to emphasize that this syndrome is observed rarely in the childhood and should be considered not only in the differential diagnosis of cutaneous lesions, but also in the differential diagnosis of various system hemorrhages.

Is the MDR1 C3435T polymorphism responsible for oral mucositis in children with acute lymphoblastic leukemia?

BACKGROUND AND AIM: Although the functional consequences of MDR-1 polymorphisms have been the subject of numerous studies, to the best to our knowledge, associations with clinical side effects of anticancer drugs have yet to be assessed. Our aim was to clarify any role of the C3435T polymorphism of the MDR1 gene in oral mucositis and its relation with elevated reactive oxygen species (ROS) levels, in children with acute lymphoblastic leukemia (ALL). MATERIALS AND METHODS: The distribution of the MDR-1 C3435T polymorphism in 47 patients with ALL was determined by RFLP and compared with that of 68 healthy controls. RESULTS: There were no association in distribution of genotypes of MDR-1 C3435T polymorphism and the risk of ALL. Oral mucositis were detected in 78.7% (n=37) of the patients and significantly related to the MDR-1 CT genotype (p=0.042), as confirmed by logistic regression analysis. CONCLUSION: Our preliminary data suggest that children carrying the CT genotype are more prone to develop oral mucositis, which might mean that the heterozygous genotype leads to accumulation of more reactive oxygen species. Since a limited number of patients was investigated, further studies are needed to confirm these findings.

Infantile hemangiomas, complications and follow-up.

OBJECTIVE: To study the risk factors for hemangioma-related complications, treatment indications and analyze the outcome of patients with infantile hemangioma. DESIGN: Retrospective. SETTING: University hospital. PATIENTS: Fifty-five patients (1-69 months; median: 12 months) with infantile hemangioma with mean follow-up 19 months. The eligibility was based on the criteria of the International Society for the Study of Vascular Anomalies (ISSVA). INTERVENTION: The surgical treatment included total excision whereas medical treatment was carried out by interferon and /or corticosteroids. MAIN OUTCOME MEASURES: Data was collected including sex, age, prematurity, age at onset, number, anatomic location and size of hemangioma, age at treatment, cause of treatment decision, family history, presence of extra malformations, involvement of internal organs, presence of life altering or life threatening complications, response to treatment, dose and duration of medications, complications associated with treatment, follow-up period, and final outcome. RESULTS: Thirty-four (62%) patients were followed-up without treatment, whereas 21 others underwent treatment including steroids, interferon, and surgery. The size of hemangioma was a major factor that predicted hemangioma-related complications (P=0.002). Patients with hemangioma related complications had bigger lesions (size >40 cm² or the longest size on a single plane >5 cm). Nineteen patients (34%) had complications, but only 8 (14.5%) out of them had life or function-threatening complications. CONCLUSION: Although dosing and treatment protocol is still debatable, steroids and interferon are good options for hemangioma treatment. The management strategy should be individualized for each case.

SET oncogene is upregulated in pediatric acute lymphoblastic leukemia.

AIMS AND BACKGROUND: The SET gene is a target of chromosomal translocations in acute leukemia and encodes a widely expressed multifunctional phosphoprotein. It has been shown that SET is upregulated in BCR-ABL1-positive cell lines, patient-derived chronic myeloid leukemia CD34-positive cells, and some solid tumors. METHODS AND STUDY DESIGN: We determined the expression level of SET in 59 pediatric acute lymphoblastic leukemia patients who were BCR-ABL-negative using quantitative real-time reverse-transcriptase-polymerase chain reaction. Results. We showed that SET expression was significantly upregulated in 96.5% of B-acute lymphoblastic leukemia (28 of 29; 16.6 fold) and 93% of T-acute lymphoblastic leukemia (28 of 30; 47.6 fold) patients. This upregulation was not associated with any clinical features or overall and relapse-free survival. CONCLUSIONS: Our results showed that SET is significantly overexpressed in pediatric acute lymphoblastic leukemia samples, and an increased level of SET might contribute to leukemic process.

Analysis of Chromosomal Aberrations and FLT3 gene Mutations in Childhood Acute Myelogenous Leukemia Patients.

OBJECTIVE: To identify the well-known common translocations and FLT3 mutations in childhood acute myelogenousleukemia (AML) patients in Turkey. MATERIAL AND METHODS: The study included 50 newly diagnosed patients in which t(15;17), t(8;21), and inv(16)chromosomal translocations were identified using real-time PCR and FLT3 gene mutations were identified via direct PCR amplification PCR-RE analysis. RESULTS: In all, t(15;17) chromosomal aberrations were observed in 4 patients (8.0%), t(8;21) chromosomal aberrationswere observed in 12 patients (24.0%), inv(16) chromosomal aberrations were observed in 3 patients (6.0%), and FLT3-ITD mutations were observed in 2 patients (4.0%); FLT3-D835 point mutation heterozygosity was observed in only 1patient (2.0%) patient. CONCLUSION: Despite of the known literature, a patient with FLT3-ITD and FLT3-D835 double mutation shows a bettersurvival and this might be due to the complementation effect of the t(15;17) translocation. The reportedmutation ratein this article (4%) of FLT3 gene seems to be one of the first results for Turkish population.

Evaluation of PAX5 gene in the early stages of leukemic B cells in the childhood B cell acute lymphoblastic leukemia.

B-lineage acute lymphoblastic leukemia (B-ALL) is a common subtype of acute leukemia in children. PAX5 plays a central role in B-cell development and differentiation. In this study, we analyzed PAX5 expression levels, transactivation domain mutations/deletions in B-ALL patients (n=115) and healthy controls (n=10). Relative PAX5 mRNA levels were significantly increased in B-ALL patients (p<0.0001). PAX5 expression was also evaluated in three different B-ALL subgroups (pro B, Common B and Pre B ALL) and showed stage specific expression levels. Pro B (p=0.04) and pre B (p=0.04) patients showed significantly high PAX5 mRNA levels compared to stage specific controls. At least one deletion of exons 7-8 or 9 has been identified in the 41% of the patients. CD34 positivity in patients and presence of large deletions (Δ7/8/9) showed a significant correlation (p=0.05). None of our patients showed PAX5 point mutations, but two previously identified SNPs (rs3780135 and rs35469494) were detected. Our results support that PAX5 is a critical factor in B-ALL development and aberrant PAX5 expression especially at early stages may leads to leukemic transformation.

Upregulation of T-Cell-Specific Transcription Factor Expression in Pediatric T-Cell Acute Lymphoblastic Leukemia (T-ALL).

OBJECTIVE: T-cell acute lymphoblastic leukemia (T-ALL) is associated with recurrent chromosomal aberrations andabnormal ectopic gene expression during T-cell development. In order to gain insight into the pathogenesis of T-ALLthis study aimed to measure the level of expression of 7 T-cell oncogenes (LMO2, LYL1, TAL1, TLX1, TLX3, BMI1, andCALM-AF10) in pediatric T-ALL patients Material and Methods: LMO2, LYL1, TLX1, TLX3, BMI1, TAL1, and CALM-AF10 expression was measured usingquantitative real-time PCR in 43 pediatric T-ALL patients. RESULTS: A high level of expression of LMO2, LYL1, TAL1, and BMI1 genes was observed in a large group of T-ALL.Several gene expression signatures indicative of leukemic arrest at specific stages of normal thymocyte development(LYL1 and LMO2) were highly expressed during the cortical and mature stages of T-cell development. Furthermore,upregulated TAL1 and BMI1 expression was observed in all phenotypic subgroups. In all, 6 of the patients had TLX1and TLX3 proto-oncogene expression, which does not occur in normal cells, and none of the patients had CALM-AF10fusion gene transcription. Expression of LYL1 alone and LMO2-LYL1 co-expression were associated with mediastinalinvolvement; however, high-level oncogene expression was not predictive of outcome in the present pediatric T-ALLpatient group, but there was a trend towards a poor prognostic impact of TAL1 and/or LMO2 and/or LYL1 protooncogeneexpression. CONCLUSION: Poor prognostic impact of TAL1 and/or LMO2 and/or LYL1 proto-oncogene expression indicate the needfor extensive study on oncogenic rearrangement and immunophenotypic markers in T-ALL, and their relationship totreatment outcome. CONFLICT OF INTEREST: None declared.