Transient Myeloproliferative Disorder and Down Syndrome Is there a link?

An extremely premature male neonate presented with an unusual multisystem dysfunction within the first 24 to 48 hours of life. The unfolding of clinical events and investigations revealed a transient myeloproliferative disorder (TMD). TMD was the main indication for karyotyping of this premature infant without clinical symptoms of Down syndrome. The awareness of TMD in a newborn warrants karyotype analysis to look for trisomy 21 and a close surveillance because of its potential progression to true leukaemia.

Predictors of impending acute chest syndrome in patients with sickle cell anaemia.

Acute chest syndrome (ACS) is a major complication of sickle cell anaemia (SCA) and a leading cause for hospital admissions and death. We aimed to study the spectrum of clinical and laboratory features of ACS and to assess the predisposing factors and predictors of severity. A retrospective case-control cohort was studied by retrieving patient information from electronic medical records after ethical approval. One hundred adolescents and adults with SCA and hospital admissions for ACS were identified through the discharge summaries, along with 20 additional patients presenting with VOC, but without ACS (controls). Among the patients with ACS, fever (\u3e38.5 °C), reduced oxygen saturation (\u3c95) and asplenia significantly differed when compared to those of controls (p \u3c 0.05, chi-squared test). The degree of severity was reflected in the use of non-invasive ventilation (NIV), simple and exchange transfusions, and the presence of bilateral pleural effusions and multi-lobar atelectasis/consolidation, which were significantly higher in the cases with ACS than in the controls. Lower haemoglobin (Hb) and high WBC counts were also significantly different between the two groups (p \u3c 0.05, Student’s t test). Using logistic regression, our study further demonstrated that asplenia, fever, and reduced O2 saturation, along with low Hb and leukocytosis, were important predictors for the development of ACS

THE USE OF HPLC AS A TOOL FOR NEONATAL CORD BLOOD SCREENING OF HAEMOGLOBINOPATHY - A VALIDATION STUDY

Background: Newborn cord blood screening identifies infants with underlying haemoglobinopathies before they develop the characteristic symptoms or sequelae.  Aims: This study was performed to validate the interpretation high-performance chromatography (HPLC) along with complete blood count (CBC) results as a tool for universal neonatal screening of hemoglobin disorders in Oman.  Methods: HPLC and CBC data on subjects who participated in the National Neonatal screening program at birth were obtained from archival records. The results recorded at birth were compared with a second study performed on the same subjects, after approval from the local medical research and ethics committee. Results: Only 290 subjects from amongst the original cohort of 3740 newborns could be recalled between April 2010 to March 2011, to repeat HPLC and CBC, as well as perform confirmatory DNA studies, wherever necessary. All these subjects had been documented to show an initial abnormal result. 31 cases who had no HbA at birth on HPLC were confirmed as either homozygous β-thalassaemia major (n=5 subjects) or homozygous sickle cell anemia (n=26 subjects) by appropriate DNA analysis. Additionally, amongst 151 subjects, 72 subjects were studied in the initial study by Hb Bart’s quantitation using aalpha thalassaemia short program at birth. In this cohort, 42 subjects with Hb Bart’s >1% at birth could be confirmed as having either deletional or non-deletional thalassaemia by GAP PCR studies. No case of HbH was detected in this cohort. Further, carrier status for structural hemoglobin variants (HbS, HbC, HbD, HbE) (n=67) and beta thalassaemia allele with low HbA at birth (n=29 out of 41) were confirmed by relevant molecular studies. Conclusions: The study validated the earlier observation by 100% concordance with results of CBC and HPLC. Presence of Hb Bart’s at birth does not always mean the presence of alpha thalassemia, as subjects with Hb Bart’s was below 1% by quantitation, were shown to be normal by molecular studies.   Key Words: Neonatal, screening, HPLC validation, haemoglobinopathy, sickle cell disease, thalassaemi

Utility of Magnetic Resonance Imaging T2* in Diagnosing and Monitoring Severe Cardiac and Hepatic Siderosis

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CLINICAL AND LABORATORY FEATURES OF SICKLE CELL DISEASE S/D PUNJAB: IMPACT OF HBF AND HYDROXYUREA

Background: Sickle cell disease (SCD) is a major public health issue worldwide with high morbidity and mortality. SCD SD Punjab is the third most common genotype of SCD in Oman and is associated with several serious complications. The aim of the study is to establish the clinical and laboratory features of SCD patients with SD double heterozygotes and study the impact of haemoglobin F, hydroxyurea, and other modulators on the disease severity. Methods: We analyzed the electronic medical records of 52 consecutive SCD patients who were diagnosed as double heterozygote SD Punjab between 2006 and 2022. The study was approved by the local medical research and ethics committee. The data captured included SCD-related complications and current clinical and laboratory indices. Data from other studies on other SCD genotypes were used as historical controls.   Results: 52 patients (31 males, 21 females) who formed this cohort had a median age of 32 years with an interquartile range (IQR) of 21-39.8 years. 37(71.2%) had 3 vasooclusive (VOC) episodes per year. SCD-related complications included Acute Chest Syndrome (ACS) (48%), Gall stones (26.9%), Avascular necrosis (AVN) (28.8%), Stroke (13.5%) and splenic sequestration (7.7%), whereas 5 (9.6%) patients of this cohort died. Surgical and Autosplenectomy were seen in 18 (34.6%). These findings were similar to other SCD genotypes in this community.19 (57.6%) were taking Hydroxyurea (HU) amongst the 33 patients who were prescribed HU. Haematological parameters showed a median (IQR) Hb (g/dl), MCV (fl), Retic count (%), WBC count(X109/L) and Platelet count(X109/L) of 9.7 (8.5-11.3), 74.9 (68.4-79.8), 4 (3.2-5.7), 9.9 (8.1-12.6) and 309 (239-428) respectively. The haemoglobin electrophoresis showed an elevated HbF, whereas serum bilirubin and LDH were elevated amongst the biochemical parameters. The use of hydroxyurea showed no impact on VOC, ACS, AVN, Stroke or mortality.   Conclusion: SD Punjab is the third most common SCD genotype in Oman and was associated with recurrent VOC, ACS, AVN, and gall stones comparable to other SCD genotypes. Patients with > 3 VOC/year had significantly increased incidence of Stroke, AVN, and gallstones. However, HU was not associated with improved prognosis and better survival in this cohort of patients. Keywords: Sickle Cell Disease; Haemoglobin SD Punjab; vaso-occlusive crises; acute chest syndrome; Avascular Necrosis; HbF; hydroxyurea

A Novel Mutation (Q694X) in the ITGB3 Gene Causing Glanzmann’s Thrombasthenia from the Sultanate of Oman

Background: Glanzmann Thrombasthenia (GT) results from mutations in the genes ITGA2B and ITGB3, located on chromosome 17q21–23 which encodes the platelet glycoprotein αIIbβ3 complex, namely GPIIb (αIIb) and GPIIIa (β3), the fibrinogen receptors on platelets, which play an important role in platelet aggregation. Patients with GT can require frequent hospitalization and can be a burden on the nation’s health resources. The possibility that GT could be cured by gene replacement therapy makes it essential to study the molecular basis of the GT patients in a particular family or kindred. Objectives: Our aim was to identify the underlying mutations responsible for GT in Omani patients in order to establish a strategy for genetic counseling and carrier detection to prevent the occurrence of the homozygous state by prenatal diagnosis. Methods: GT was diagnosed in a 17 year old Omani female at the Sultan Qaboos University Hospital. The diagnosis of GT was based on clinical features, platelet aggregometry and biochemical studies. Platelet surface expression of GPIIb/IIIa was also studied by flowcytometry. Molecular studies performed at Medical Genetics Department, Tsukuba University, Japan, include DNA sequencing of all exons and exon-intron junctions of ITGA2B and ITGB3 of the two genes by the ABI 3100 Genetic Analyzer®. [Applied Biosystems, Foster City, CA, USA]. Genomic DNA was also analyzed by Illumina Human-1 Bead Chip Illumina® (Illumina Inc., San Diego, CA, USA) to exclude the whole region of the two genes that could produce an apparent homozygous state. Results: We have identified a novel nonsense causative mutation (Q694X) by sequencing the ITGB3 gene. [Figure 1a & b]. In addition, sequencing ITGB3 gene also revealed 2 SNPs (rs 3809863; IVS14+9C/T, rs 3809865; 3383T/A). The Micro-Array assay using Illumina Human-1 Bead chip excluded the possibility of deletion of these genes in chromosome 17 in this patient. Summary/Conclusion: A stop codon was found in exon 13 of ITGB3 gene causing the translated protein to be abnormally shortened. It is hypothesized that the altered form of ITGB3 gene is both extremely unstable and rapidly degraded after its biosynthesis, leading to a loss of function of the protein. Further RNA expression studies, transfection tests and cDNA sequencing are ongoing to elucidate the molecular mechanisms responsible for GT

Influence of Voxelotor–hemoglobin complexes in the estimation of hemoglobin S levels by the current standard of care laboratory evaluation techniques

BackgroundSickle cell disease is an inherited disorder characterized by the presence of sickle hemoglobin (HbS). The process of Hb molecule polymerization is a pivotal step in the sickling process. Voxelotor, a recently approved novel therapeutic agent, is known to interfere with polymerization. We aim to study the impact of Voxelotor on Hb variants analysis using high performance liquid chromatography (HPLC).Material and methodsWe are reporting the impact of Voxelotor on Hb variants analysis using HPLC after an informed consent and medical research committee approval. Data was collected from eight patients who are enrolled in the GBT440-034OL study using electronic medical records, to evaluate the Hb levels, hemolytic markers and the clinical response.ResultsOur patients were well-balanced for gender, with a mean age of 31.1 years (19–50). Six patients showed a significant improvement in the Hb level, with reduced reticulocytes, bilirubin, LDH and an improved clinical outcome. Interestingly, these patients showed the appearance of a split band of Hb S and D on HPLC impacting significantly on HbS level. Two patients did not show any improvement on laboratory parameters, and no changes on their HPLC analysis.ConclusionsWe report here eight patients on Voxelotor therapy, six of which showed improved hemolytic markers and anemia and demonstrated the appearance of HbD peak on the HPLC chromatogram. Therefore, the absence of HbD on HPLC or other laboratory methods for estimating HbS in patients on Voxelotor therapy, gives the clinician a possible hint regarding the patient's compliance with the drug

Predicting risk factors for thromboembolic complications in patients with sickle cell anaemia - lessons learned for prophylaxis

Objective: To assess the clinical and laboratory predictors of venous thromboembolism (VTE) in patients with sickle cell anaemia (SCA) and its relationship to morbidity and mortality. Methods: This retrospective case-control study analysed data from patients with SCA that experienced VTE compared with matched control patients with SCA but no VTE (2:1 ratio). Results: A total of 102 patients with SCA were enrolled (68 cases with VTE and 34 controls). Amongst the 68 cases (median age, 29.5 years), 26 (38.2%) presented with isolated pulmonary embolism (PE). A higher prevalence of splenectomy (73.5% versus 35.3%) was observed in the cases compared with the controls. A significantly higher prevalence of central venous catheter (CVC) insertion (42.6% versus 8.8%) was observed in the cases compared with the controls. High white blood cell counts, serum lactic dehydrogenase (LDH), bilirubin and C-reactive protein (CRP) and low haemoglobin (Hb) and HbF were significant risk factors for VTE. Forty-two cases (61.8%) developed acute chest syndrome, 10 (14.7%) had a stroke and seven (10.3%) died. Conclusions: VTE in patients with SCA has a high impact on morbidity and mortality. PE was the leading presentation of VTE, with CVC insertion, high LDH, bilirubin, CRP and white blood cell counts along with low Hb and HbF constituting other significant risk factors

Deferasirox (Exjade®) significantly improves cardiac T2* in heavily iron-overloaded patients with β-thalassemia major

Noninvasive measurement of tissue iron levels can be assessed using T2* magnetic resonance imaging (MRI) to identify and monitor patients with iron overload. This study monitored cardiac siderosis using T2* MRI in a cohort of 19 heavily iron-overloaded patients with β-thalassemia major receiving iron chelation therapy with deferasirox over an 18-month period. Overall, deferasirox therapy significantly improved mean ± standard deviation cardiac T2* from a baseline of 17.2 ± 10.8 to 21.5 ± 12.8 ms (+25.0%; P = 0.02). A concomitant reduction in median serum ferritin from a baseline of 5,497 to 4,235 ng/mL (−23.0%; P = 0.001), and mean liver iron concentration from 24.2 ± 9.0 to 17.6 ± 12.9 mg Fe/g dry weight (−27.1%; P = 0.01) was also seen. Improvements were seen in patients with various degrees of cardiac siderosis, including those patients with a baseline cardiac T2* of <10 ms, indicative of high cardiac iron burden. These findings therefore support previous observations that deferasirox is effective in the removal of myocardial iron with concomitant reduction in total body iron