ALBERT

Description: Background: In spite of guidelines recommending the no need for coagulation profile prior to ENT surgeries when challenging history of bleeding is negative, yet surgeons still practice it. Cost and delaying surgeries are major issues faced when insignificant abnormalities are found in the coagulation profile results. In 2008, British Committee for Standards of Hematology has published guidelines (1) on assessing the bleeding risk prior to surgeries or invasive procedures, which stated that the indication for sending a coagulation profile is best based on the bleeding history of the patient. Aim: This study aimed to measure unbiased estimate of hemostatic outcomes in ENT surgeries in relation to coagulation testing. Methods: All patients who underwent ENT surgeries from three tertiary hospitals during the period from 1st July 2016 to 1st January 2017 were enrolled in the study. The retrieved data included gender, age, type of surgery, results of coagulation blood test (if done), other laboratory test results (complete blood count, biochemical profile, etc.), postoperative bleeds, how it was managed, need for blood transfusion and whether the patient required another surgery to stop the bleeding or not. Patients with known bleeding history or previous coagulation derangement were excluded from the study. The primary outcome was post-operative bleeding. Results: The study included data from 730 patients who underwent ENT surgical procedures. They were 432 males and 298 females. Their mean age was 19.6 + 16.92 year. Out the 730 patients, 372 patients were interviewed for a challenging bleeding history alone (group 1) and 358 were interviewed plus a pre-operative coagulation profile check (Group 2). Total of fourteen patients (1.9 %) developed postoperative bleeding. None of them was due to abnormal bleeding tendency and they didn't require any hemostatic support. Six of them bled early (primary hemorrhage) while at the hospital due to surgical reasons (surgical site bleed that required suturing). Eight patients had delayed postoperative bleeds, after being discharged (due to eating hard food/Trauma). Only total of four patients had major bleeds, requiring surgical intervention. Conclusion: Despite guidelines recommending not doing coagulation testing prior to surgeries, many local surgeons still consider preoperative coagulation testing as a standard practice to evaluate the patients bleeding risk prior to any surgical procedure. This has resulted in unnecessary delays in surgeries (reaching up to a year in many patients) besides the parents/patients anxiety and additional total cost. We recommend awareness campaigns for surgeons and adhering to guidelines of taking detailed hemostatic history. Reference: Chee YL1, Crawford JC, Watson HG, Greaves M. Guidelines on the assessment of bleeding risk prior to surgery or invasive procedures. British Committee for Standards in Haematology. Br J Haematol. 2008 Mar;140(5):496-504. Keywords: Coagulation testing, Bleeding History, Surgery Disclosures No relevant conflicts of interest to declare.

Description: Non-Hodgkin's lymphoma (NHL) is the most common hematological malignancy in the US. Many types remain incurable despite response to initial therapy and achievement of complete remission (CR). Advanced laboratory techniques like multicolor flow cytometry (MCF) and polymerase chain reaction (PCR) have demonstrated persistence of rare malignant cell population post therapy referred to as minimal residual disease (MRD). However, the functional and biological characteristics of this population have not been fully elucidated. Established B-lymphoma cell lines (B-NHL) and patient-derived samples (PDS) were analyzed using 8-color FCM of leukemia and lymphoma antibody panels (28 antibodies). The CD34+ sub-population was enriched using in vitro exposure to 2-chlorodeoxyadenosine (2-CdA), and a CD34-coated magnetic beads isolation procedure (Miltenyi Biotech). Genetic analysis of CD34+ and CD34-/parent cell fractions was done by karyotyping, and by chromosomal microarray (CMA) using the oligonucleotide-single nucleotide polymorphism (Oligo-SNP), whole genome Agilent 180K GGXChip+SNP (Agilent Technologies, Inc). Sensitivity to chemotherapy was assayed by short-term in vitro exposure to drugs. Clonogenicity was determined by soft agar colony formation assay, and proliferation was determined using DNA staining with propidium iodide and flow cytometry. The side population was determined using the fluorescent vital dye Hoechst 33342 and flow cytometry. Analysis of three B-NHL cell lines revealed the presence of a minute sub-clone (

Description: Objectives: Distinguishing between acute presentations of osteomyelitis (OM) and vaso-occlusive crisis (VOC) bone infarction in children with sickle cell disease (SCD) remains challenging for clinicians, particularly in culture-negative cases. VOC and osteomyelitis have a very similar presentation in the acute stage, and both are associated with a rise in C-reactive protein (CRP) level and erythrocyte sedimentation rate (ESR). The gold standard to diagnose osteomyelitis is obtaining a positive blood culture and bone/joint biopsy which is invasive and not frequently done. Standard magnetic resonance imaging (MRI) with fat suppression sequencing (subtraction technique) may help to confirm osteomyelitis in SCD patients; however, this is frequently not done in a timely manner and is associated with false positive and false negative results. The objective of this study is to assess the discriminative impact of baseline variable and build a score to assess the diagnosis of osteomyelitis in pediatric patients with SCD. Methods: A retrospective study of all patients with SCD, aged 1 to 18 years old with suspected osteomyelitis. The study covered a period of over 4 years (January 2015- June 2019) at Sultan Qaboos University Hospital, which is the main tertiary care and referral facility in Oman. All the patients were subjected to a complete clinical assessment, laboratory blood tests including, CBC, CRP, blood and aspirated fluid (if applicable) culture, and standard MRI with fat suppression sequencing of the affected bone. A clinical and laboratory score was designed to test whether it can help to prove or disprove the diagnosis in likely cases (Table 1). Results: A total of 43 patients fulfilled the inclusion criteria. Their mean age was 8.7 years +/-3.4. Male to female ratio was 1.87:1. All patients have been initiated on antibiotic therapy as osteomyelitis based on the clinical suspicion and MRI findings. The mean score in the 11 patients with confirmed osteomyelitis was 11/13. Thirteen patients were classified as likely osteomyelitis. Their mean score was 7.5/13. Seventeen patients were confirmed to have VOC by the clinical course (fast resolution of fever, local signs of inflammation and the drop in inflammatory markers). Their mean score was 5.7/13 (Table 2). Conclusion: Differentiating VOC from osteomyelitis in children with SCD who present with fever and bone pain is a difficult task. Our proposed score assigned different mean score to different clinical entity (confirmed OM vs. likely OM vs. VOC). This score may assist clinicians to differentiate these entities. A larger prospective study is needed to confirm and validate the score. Disclosures Tbaileh: Sultan Qaboos University Hospital: Other: Data Collection, Data Input , Discussion of data with my seniors. Al-Khabori:Roche: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; SOBI: Honoraria; AstraZeneca: Honoraria; NovoNardisk: Membership on an entity's Board of Directors or advisory committees; Servier: Membership on an entity's Board of Directors or advisory committees; Shire (Takeda): Membership on an entity's Board of Directors or advisory committees. Wali:Sultan Qaboos University Hospital: Employment.

Description: Background Deep venous thrombosis (DVT) refers to the formation of a thrombus within a deep vein that frequently occurs after surgical procedures, trauma, in the presence of cancer and immobilization conditions. DVT is a major health problem that causes high rate of morbidity and mortality in the general population. Hyper coagulation states such as antithrombin-III, protein-C and protein-S deficiencies, contribute to formation of DVT. Congenital and acquired gene mutations are other risk factors that stimulate formation of thrombus. Our aims in this study was to molecularly analyze the patients with DVT and assess the impact of common mutations of MTHFR (C677T) (A1298C), PAI-1, Prothrombin 20210 and FV Leiden mutation on occurrence of deep venous thrombosis. Methods This long-term study was conducted from June 2009 to July 2013 on 221 patients with deep venues thrombosis. Two hundred and twenty-one age and sex matched individuals were also chosen as control group. The diagnosis of venous thromboembolic disease was based on patient’s history, clinical findings and D-dimer test. Finally deep venous thrombosis was confirmed with Doppler ultrasonography. In addition, all participants were asked to complete a standardized questionnaire on acquired risk factors for venous thrombosis. After confirmation of DVT, both groups were assessed molecularly for five mutations including, MTHFR C677T, MTHFR A1298C, PAI-1 4G/5G, Prothrombin 20210 and FV Leiden. The relationship between these mutations and the risk of DVT was calculated using logistic regression and expressed as an OR with a 95% confidence interval (CI). Results The mean age of patients and control group were 38±0.8 and 3.7± 0.7 years. Our results revealed that the MTHFR C677T (OR 2.9, 95% 95% CI 1.1 to 7.5) and MTHFR A1298C in heterozygote manner (OR 4.3, 95% CI 1.4 to 13.7) were each associated with an increased risk of DVT. The OR associated with being a carrier of the PAI-1 4G/5G genotype was 2.9 (95% CI 1.14 to 7.5). There was a 4-fold increased risk of DVT associated with Prothrombin 20210 mutation in heterozygote manner (OR 4.3, 95% CI 1.4 to 13.7). For patients who were heterozygous for FV Leiden mutation OR DVT was 2.6 (95% CI 1.3 to 5.0). Conclusion Our findings suggest that genetic risk factors have a contributory role on occurrence of DVT. Disclosures: No relevant conflicts of interest to declare.

Description: Idiopathic autoimmune thrombocytopenia (ITP) is an autoimmune disease characterized by autoantibody-mediated platelet destruction. The major platelet antigens that autoantibodies are directed against in ITP are GPIIbIIIa and GPIbα. Intravenous immunoglobulin G (IVIG) is a treatment used in ITP; however, some patients are refractory to this treatment and the mechanisms of action of IVIG in this disease are not fully understood. We tested the hypothesis that IVIG may not be equally effective in preventing ITP caused by GPIIbIIIa versus GPIbα anti-platelet antibodies. Thrombocytopenia was induced in Balb/c mice using three monoclonal antibodies against either mouse platelet GPIIbIIIa (JON1, 2, −3) or against GPIbα (p0p 3, 4, −5). Mouse platelet counts were performed daily from day one (pre-treatment) until day five using a flow cytometric assay. The efficacy of IVIG in inhibiting monoclonal antibody-induced platelet destruction in mice was assessed by intraperitoneal injection of IVIG (2 g/kg) 24-hours before anti-platelet antibody injections (7 mg/mouse, i.v.) on day two. We found that pre-treatment with IVIG resulted in a significantly higher platelet count on day three in all groups of anti-GPIIbIIIa-injected animals (n=3/antibody; for JON1, P=0.002; JON2, P=0.015; JON3, P=0.002) as compared to albumin-treated controls. In contrast, IVIG failed to prevent platelet clearance and thrombocytopenia on day three in two anti-GPIbα antibody-treated groups (p0p3 and p0p5, n=3/antibody), but did inhibit platelet destruction in mice that were injected with p0p4 antibody (P=0.0003). Our results indicate that the efficacy of IVIG treatment in preventing ITP induced by these anti-platelet antibodies is affected by their antigen specificities. These data also suggest that patients with ITP mediated by GPIbα may be less responsive to IVIG treatment than those with ITP mediated by GPIIbIIIa antibodies.

Description: Recent microarray gene expression profiling studies have identified gene signatures predictive of outcome, so-called “indicator” genes, for diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL). However, measurement of these genes in routine practice remains difficult. We applied real-time polymerase chain reaction (PCR) to polyA cDNAs prepared from 106 archived human frozen lymph nodes (63 of FL, 25 of DLBCL, 10 reactive lymph nodes, and cases with paired samples of FL [4] and subsequent DLBCL [4]). Reverse transcription and polyA reverse transcriptase (RT)–PCR was performed, and resultant cDNA was probed by real-time PCR for 36 candidate indicator genes, selected from microarray studies. Nine genes showed statistically significant different expression between FL and DLBCL, including cyclin B, COL3A1, NPM3, H731, PRKCB1, OVGL, ZFPC150, HLA-DQ-a, and XPB. Of these, cyclin B, NPM3, and COL3A1 were higher in DLBCL. Six genes showed statistically significant higher expression in the neoplastic nodes compared with reactive nodes, namely PRKCB1, BCL-6, EAR2, ZFX, cyclin B, YY1. High levels of YY.1 were associated with a shorter survival interval in both FL and DLBCL. The method is simple, sensitive, and robust, facilitating routine use and may be used as a platform for clinical measurement of prognostic gene signatures.

Description: ITP in adults is an autoimmune disease characterized by antibody-mediated thrombocytopenia. A significant number of patients relapse after initial therapy with prednisone and splenectomy when necessary, and require other therapy for continuing thrombocytopenia. Rituximab, an anti-CD20 chimeric monoclonal antibody has been utilized in ITP refractory to other modes of treatment (Feurestein, M., et al. The use of Rituximab in 28 patients with immune thrombocytopenic purpura (ITP). Proc. Am. Soc. Clin. Onc.22:187, 2003). We report on the long-term responses possible in ITP treated with Rituximab. Twenty-two patients with ITP refractory to initial conventional therapies with platelet counts 50,000/ul but 150,000/ul). Patient characteristics included 5 males and 17 females with ages 24–83 years (median 58). Twenty had undergone splenectomy. Thirteen patients (59%) responded to Rituximab. Six responses were PR with durations lasting 2, 2, 3, 3, 4, and 6 months. Continuing Rituximab monthly after initial therapy of 4 weeks did not produce improved platelet counts in patients who failed Rituximab or who achieved PR. Seven responses were CR with durations of 12, 20+, 25+, 29+, 38+, 40+, and 48+ months. The one patient who relapsed at 12 months was retreated with Rituximab but did not respond. There was no correlation between response and age, sex, or duration of ITP. Neither of the patients who declined prior splenectomy responded. There were no serious complications of Rituximab infusions. Twenty-five percent of patients had mild first infusion reactions. Rituximab can produce long-term CR in 27% of patients with ITP refractory to initial therapy.

Description: Background: The management of MCL is a significant therapeutic challenge, especially in patients with relapsed or refractory disease, who are generally refractory to salvage chemotherapy. Although recent studies have shown the clinical utility of radioimmunotherapy (RIT) in relapsed and transformed indolent B-cell lymphoma, the clinical efficacy of this treatment modality in patients with MCL is unknown. We report the results of an ongoing phase II clinical trial of yttrium 90 ibritumomab tiuxetan (Zevalin®) in patients with relapsed and refractory MCL. Patients and Methods: Patients with relapsed or refractory MCL with measurable disease, age 〉18 years, and performance status 1,500/mm3, platelets 〉100,000/mm3), liver, and kidneys. Patients were excluded if they had prior stem cell transplantation, RIT, CNS lymphoma, HIV infection, pleural effusion, HAMA reactivity, or circulating lymphoma cell count 〉5000/mm3. Patients with pretreatment platelet counts 〉150,000/mm3 received a dose of Zevalin at 0.4 mCi 90Y/kg (maximum dose 32 mCi), whereas those with platelet counts

Description: Background: Platelets are critical for maintaining hemostasis, but inappropriate platelet activation can lead to pathogenic thrombosis. It has been demonstrated that the platelet integrin αIIbβ3 is essential for platelet aggregation and is also a major target antigen in immune thrombocytopenias (e.g. ITP). Current monoclonal antibodies (mAbs) against this protein complex have been generated using traditional methods involving cross-species immunization (e.g. mouse proteins into rat hosts). These approaches may generate a limited repertoire of anti-β3 mAbs since the antigenicity of the protein and the variety of epitopes targeted are based on amino acid sequence differences between the two species and integrin family members are highly conserved. Additionally, studies in murine models of ITP are hampered by the use of xenogeneic antibodies rather than syngeneic antibodies. Methods: We developed a method to generate mouse anti-mouse β3 integrin mAbs utilising β3 gene deficient mice (β3−/−) immunized with wild-type platelets. To generate antibodies specific to the PSI domain (HPA-1 region) of β3 integrin, β3−/− mice were immunized with the recombinant murine PSI domain of β3 integrin. Platelet binding and specificity were determined by flow cytometry and western blot. In vitro effects on platelet function were measured using aggregometry. Different doses of mAbs (5, 10, and 15 μg/mouse) were injected intravenously to induce thrombocytopenia in vivo. Results: A total of twelve mAbs were generated against native β3 integrin (JAN A1, B1, C1, D1 and DEC A1 and B1, 9D2, M1) or recombinant PSI domain (PSI A1, B1, C1, E1). The mAbs were specific for β3 integrin; no binding was observed using β3−/− platelets. Isotyping showed that DEC A1 and DEC B1 are IgG3, PSI E1 is IgG2b, and all other mAbs are IgG1. The anti-PSI domain mAbs recognized linear epitopes and the anti-native β3 mAbs recognized conformational epitopes. All mAbs, with the exception of JAN A1 and B1, cross-reacted with human platelets. JAN C1, JAN D1, DEC A1, 9D2, M1, and all anti-PSI antibodies inhibited mouse platelet aggregation. These antibodies, except DEC A1, 9D2 and M1, also inhibited human platelet aggregation. One anti-PSI domain antibody (PSI B1), however, directly induced human platelet aggregation in the absence of agonist in platelet rich plasma but not in PIPES buffer. This suggests that PSI B1 may initiate conformational changes in β3 integrin and promote fibrinogen binding. Six anti-β3 mAbs (JAN A1, B1, C1 and D1, 9D2 and M1) induced severe dose-dependent thrombocytopenia in mice, while the anti-PSI domain mAbs induced only a mild decrease in platelet count. Interestingly, the two IgG3 mAbs (DEC A1 and B1) did not induce thrombocytopenia. Conclusion: This approach to generating mouse anti-mouse β3 integrin mAbs using β3−/− mice was successful. Different anti-β3 mAbs had different effects on platelet aggregation, and on the induction of thrombocytopenia. These mAbs may be useful reagents for research in thrombosis and immune thrombocytopenia and as novel anti-thrombotic therapeutics.

Description: Myelodysplastic syndrome (MDS) is a heterogeneous group of clonal hematopoietic diseases characterized by impaired hematopoiesis and progression to acute myeloid leukemia (AML). Although rare, several monogenic causes of familial MDS/AML have recently been molecularly defined. We studied two families with variable manifestation of cytopenia, MDS with cytogenetic aberrations involving chromosome 7, immunodeficiency, and neurologic disease consistent with ataxia-pancytopenia syndrome. Genetic studies uncovered heterozygous missense variants (p.Arg986Cys and p.Ile891Thr) in SAMD9L, a tumor suppressor gene located on chromosome 7. Consistent with a gain-of-function effect, transfection and over-expression of both SAMD9L variants decreased cell proliferation relative to wild-type protein. In the two families, a total of 10 individuals heterozygous for either SAMD9L mutation were identified. Three individuals developed MDS, with monosomy 7 or der(1;7)(q10;p10) as cytogenetic aberrations that encompassed the mutant SAMD9L locus. In an additional five individuals, three of which experienced a spontaneously resolved cytopenic episodes in infancy, we detected mosaic copy-neutral loss of heterozygosity of 7q by uniparental disomy, with loss of the mutated allele, or mosaic cis SAMD9L mutations. By digital PCR, we identified these events in hematopoietic progenitor cell populations, which were further enriched in B and NK cell lineages. Absent in non hematological tissues, these mutations thus represented somatic revertant mosaicism. Clinically, revertant mosaicism was associated with reduced disease severity, although in two individuals neurological manifestations persisted. Of note, two unaffected carriers without revertant mosaicism harbored an additional rare in trans germline SAMD9L p.Thr233Asn missense variant. In cellular assays, the SAMD9L p.Thr233Asn variant increased proliferation, indicating a loss-of-function effect that potentially compensates for the SAMD9L p.Arg986Cys mutation. Together, our results demonstrate that gain-of-function mutations in the tumor suppressor SAMD9L cause a disease with cytopenia, immunodeficiency, variable neurological presentation, and predisposition to MDS with chromosome 7 aberrations, where hematopoietic revertant mosaicism is common and ameliorates the clinical presentation. Disclosures Fioretos: Cantargia: Equity Ownership.