Genotype and Phenotype of Adenosine Deaminase 2 Deficiency: a Report from Saudi Arabia.

Adenosine deaminase 2 deficiency (DADA2), a rare and potentially fatal systemic autoinflammatory disease, is characterized by low or lack of ADA2 activity due to ADA2 mutations. DADA2 symptoms are variable and include vasculitis, immunodeficiency, and cytopenia. Minimal data are available from Saudi Arabia. This retrospective study conducted at seven major tertiary medical centers examined the phenotypic and genotypic variabilities, clinical and diagnostic findings, and treatment outcomes among 20 Saudi patients with DADA2 from 14 families. The median age of the study cohort was 9.5 years (4-26 years). The clinical presentation was before the age of 5 months in 25% of patients. Homozygous c.1447-1451del mutation was the most frequent ADA2 alteration (40%), followed by c.882-2A:G (30%). All tested patients exhibited absent or near-absent ADA2 activity. Phenotypic manifestations included stroke (40%), hematological abnormalities (95%), lymphoproliferation (65%), and recurrent infection (45%). Five and three patients had extracranial vasculitis features and Hodgkin lymphoma, respectively. Atypical manifestations included growth retardation (30%) and transverse myelitis. Anti-tumor necrosis factor (anti-TNF) therapy was the main treatment. Some patients underwent blood transfusion, splenectomy, cyclosporine and colony-stimulating factor therapies, and hematopoietic stem cell transplantation due to anti-TNF therapy failure. Fulminant hepatitis and septic multiorgan failure caused mortality in three patients. Thus, this study revealed the variability in the molecular and clinical characteristics of DADA2 in the study cohort with predominant aberrant hematological and immunological characteristics. Consensus diagnostic criteria will facilitate early diagnosis and treatment. Additionally, disease registries or large prospective studies are needed for evaluating rare disease complications, such as cancer.

SCAR: The high-prevalence antigen 013.008 in the Scianna blood group system.

BACKGROUND: The Scianna (SC) blood group system comprises seven antigens. They reside on the erythroblast membrane-associated glycoprotein (ERMAP). The ERMAP and RHCE genes are juxtaposed to each other on chromosome 1. We report a novel SC antigen. STUDY DESIGN AND METHODS: Blood samples came from a patient and his two sisters in Saudi Arabia. To investigate the antibody specificity we used the column agglutination technique and soluble recombinant ERMAP protein. The significance of anti-SCAR was evaluated by the transfusion history and a monocyte monolayer assay. We determined the genomic sequence of ERMAP and RHCE genes. RESULTS: The patient's serum showed an antibody of titer 8 against a high-prevalence antigen. The soluble recombinant ERMAP protein inhibited the antibody. The propositus genotyped homozygous for an ERMAP:c.424C>G variant, for which his sisters were heterozygous. The c.424C>G variant occurred in the SC*01 allele in one haplotype with the RHCE*03 (RHCE*cE) allele. No signs of hemolysis occurred following an incompatible blood transfusion. The monocyte monolayer assay was negative. CONCLUSIONS: We characterized a high-prevalence antigen, with the proposed name "SCAR," which is the eighth antigen of the Scianna blood group system (proposed designation 013.008). Individuals homozygous for ERMAP:p.(Gln142Glu) protein variant can produce anti-SCAR. Although we did not observe any sign of hemolysis at this time, the anti-SCAR prompted a change of the treatment regimen. A review of the known reports indicated that all SC alloantibodies of sufficient titer should be considered capable of causing hemolysis.

Outcome following second allogeneic hematopoietic cell transplantation: A single-center experience.

OBJECTIVE: Second allogeneic hematopoietic cell transplantation (HCT) may be indicated following relapse or graft failure following first HCT. Our retrospective single-center study sought to investigate parameters that influence post-second allogeneic HCT survival. METHOD: We investigated 92 patients who underwent second allogeneic HCT between 1980 and 2016 for relapse or graft failure following first HCT. Median age at second HCT was 41 years (range 16-68), performed for relapse in 59 patients (64%) and for graft failure in 33 patients (36%). RESULTS: On univariate analysis, 3-year OS of the entire cohort was 35% (95% CI=25-45). Eastern Cooperative Oncology Group (ECOG) score (3-year OS 48% for ECOG 0-1, 18% for ECOG 2-3, P=.0006), second HCT indication (3-year OS 43% for relapse, 20% for graft failure, P=.02), time from first HCT to relapse/graft failure (3-year OS for <12months 21%, for ≥12months 46%, P=.009), and conditioning intensity (3-year OS for MA 42% vs other regimens 23%, P=.08) significantly influenced OS. Multivariable analysis confirmed ECOG score (HR=2.15 for ECOG 2-3, 95% CI=1.32-3.51, P=.002) and second HCT indication (HR=1.67 for graft failure, 95% CI=1.02-2.75, P=.04) to independently influence survival. CONCLUSION: Second HCT may offer long-term survival particularly to patients with good performance status who relapse post-first HCT.

Diagnostic accuracy of reticulocyte parameters on the sysmex XN 1000 for discriminating iron deficiency anaemia and thalassaemia in Saudi Arabia.

INTRODUCTION: Iron deficient erythropoiesis and Thalassaemia are both associated with microcytic erythropoiesis albeit from different pathological mechanisms. Given the high prevalence of Hemoglobinopathies in the Mediterranean region, discriminating these two conditions is important. Several algorithms using conventional red cell indices have been developed to facilitate diagnosis, however, their diagnostic accuracy is low. The new generation haematology analyzers enabled the use of more innovative parameters such as reticulocyte parameters. We aimed to evaluate the diagnostic performance of the reticulocyte parameters on the Sysmex XN 1000 to distinguish between IDA and Thalassemia in our population. METHODS: We performed a retrospective analysis of blood samples sent to our laboratory for haemoglobin electrophoresis screening. We categorized our cohort into Thalassemia and Iron Deficient patients based on known diagnostic criteria. We analyzed the reticulocyte parameters using receiver operator curve analysis (ROC) and determined the cut off value for each parameter. RESULTS: Reticulocyte parameters most accurate for discriminating IDA from Thalassemia patients was: RET, RET-HE and IRF. The RET-HE had the best statistical significance for IDA patients with AUC = 0.69 for cut off 22.25. The RET-HE for dual positive patients was more accurate with AUC = 0.78 for cut off 21.25. The IRF had the best statistical significance for Alpha Thalassemia with AUC = 0.66 for cut off value 18. CONCLUSION: An IRF cut off below 15.5 and RET-HE cut off below 22.25 was the most accurate variable in predicting IDA with a sensitivity of 59.4% and 68.3%.

De Novo CD5 Negative Blastic Mantle Cell Lymphoma Presented with Massive Bone Marrow Necrosis without Adenopathy or Organomegaly.

The recent World Health Organization (WHO) classification defines mantle cell lymphoma (MCL) as a distinct entity characterized by a unique immunophenotype and a molecular hallmark of chromosomal translocation t(11;14)(q13;q32). We report an unusual case of an advanced stage of CD5 negative MCL with a blastoid variant with a massive bone marrow (BM) necrosis as an initial presenting feature, with no adenopathy or hepatosplenomegaly. The pathologic features showed blastoid variant of MCL and flow cytometry showed that the tumor cells were CD5-, CD19+, CD20+, FMC-7+, CD23-, and lambda light chain restricted. Chromosomal analysis, using karyotype and fluorescent in situ hybridization (FISH), demonstrated karyotypic abnormalities in addition to the t(11;14). Our case study may be reported as a unique case of CD5- blastic MCL with unusual presentation and findings which made the diagnosis of MCL difficult.