Global burden of transfusion in sickle cell disease.

Sickle cell disease (SCD) is the most common hereditary hemoglobinopathy. The underlying pathophysiology of the red blood cell (RBC) leads to pan-systemic complications which manifest at an early age. While curative and disease-modifying treatments exist for SCD, a key intervention in the management and treatment of SCD is RBC transfusion, which can alleviate or prevent many complications. SCD patients often require chronic RBC transfusion therapy which can result in complications, such as iron overload, alloimmunization and infection. In low- and middle-income countries (LMICs), SCD patients lack appropriate access to healthcare such as newborn screening, health education, prophylaxis for infection, and treatments to reduce both mortality and SCD-related adverse effects. Poor access to RBCs for transfusion, coupled with donated blood not meeting safety standards set by the World Health Organization, presents a significant barrier for patients requiring chronic transfusions in LMICs. Unmet needs associated with blood collection, blood component processing and recipient matching all pose a serious problem in many LMICs, although this varies depending on geographic location, political organizations and economy. This review aims to provide an overview of the global burden of SCD, focusing on the availability of current treatments and the burden of chronic RBC transfusions in patients with SCD.

Protecting vulnerable patients with inherited anaemias from unnecessary death during the COVID-19 pandemic.

With the developing COVID-19 pandemic, patients with inherited anaemias require specific advice regarding isolation and changes to usual treatment schedules. The National Haemoglobinopathy Panel (NHP) has issued guidance on the care of patients with sickle cell disease, thalassaemia, Diamond Blackfan anaemia (DBA), congenital dyserythropoietic anaemia (CDA), sideroblastic anaemia, pyruvate kinase deficiency and other red cell enzyme and membrane disorders. Cascading of accurate information for clinicians and patients is paramount to preventing adverse outcomes, such as patients who are at increased risk of fulminant bacterial infection due to their condition or its treatment erroneously self-isolating if their fever is mistakenly attributed to a viral cause, delaying potentially life-saving antibiotic therapy. Outpatient visits should be minimised for most patients, however some, such as first transcranial dopplers for children with sickle cell anaemia should not be delayed as known risk of stroke will outweigh the unknown risk from COVID-19 infection. Blood transfusion programmes should be continued, but specific changes to usual clinical pathways can be instituted to reduce risk of patient exposure to COVID-19, as well as contingency planning for possible reductions in blood available for transfusions. Bone marrow transplants for these disorders should be postponed until further notice. With the current lack of evidence on the risk and complications of COVID-19 infection in these patients, national data collection is ongoing to record outcomes and eventually to identify predictors of disease severity, particularly important if further waves of infection travel through the population.

Paediatric to adult transition care for patients with sickle cell disease: a global perspective.

Sickle cell disease is a life-threatening inherited condition designated as a public health priority by WHO. Increased longevity of patients with sickle cell disease in high-income, middle-income, and low-income countries present unprecedented challenges for all settings; however, a globally standardised solution for patient transition from paediatric to adult sickle cell disease health care is unlikely to address the challenges. We established a task force of experts from a multicountry (the USA, Europe, Middle East, and Africa) consortium. We combined themes from the literature with viewpoints from members of the task force and invited experts to provide a global overview of transition care practice, highlighting barriers to effective transition care and provide baseline recommendations that can be adapted to local needs. We highlighted priorities to consider for any young person with sickle cell disease transitioning from paediatric to adult health care: skills transfer, increasing self-efficacy, coordination, knowledge transfer, linking to adult services, and evaluating readiness (the SICKLE recommendations). These recommendations aim to ensure appropriate benchmarking of transition programming, but multisite prospective studies are needed to address this growing public health need.

Sickle Cell Disease-Genetics, Pathophysiology, Clinical Presentation and Treatment.

Sickle cell disease (SCD) is a monogenetic disorder due to a single base-pair point mutation in the ß-globin gene resulting in the substitution of the amino acid valine for glutamic acid in the ß-globin chain. Phenotypic variation in the clinical presentation and disease outcome is a characteristic feature of the disorder. Understanding the pathogenesis and pathophysiology of the disorder is central to the choice of therapeutic development and intervention. In this special edition for newborn screening for haemoglobin disorders, it is pertinent to describe the genetic, pathologic and clinical presentation of sickle cell disease as a prelude to the justification for screening. Through a systematic review of the literature using search terms relating to SCD up till 2019, we identified relevant descriptive publications for inclusion. The scope of this review is mainly an overview of the clinical features of pain, the cardinal symptom in SCD, which present following the drop in foetal haemoglobin as young as five to six months after birth. The relative impact of haemolysis and small-vessel occlusive pathology remains controversial, a combination of features probably contribute to the different pathologies. We also provide an overview of emerging therapies in SCD.

Utilising the 'Getting to Outcomes®' Framework in Community Engagement for Development and Implementation of Sickle Cell Disease Newborn Screening in Kaduna State, Nigeria.

BACKGROUND: Sickle Cell Disease (SCD) has been designated by WHO as a public health problem in sub-Saharan Africa, and the development of newborn screening (NBS) is crucial to the reduction of high SCD morbidity and mortality. Strategies from the field of implementation science can be useful for supporting the translation of NBS evidence from high income countries to the unique cultural context of sub-Saharan Africa. One such strategy is community engagement at all levels of the healthcare system, and a widely-used implementation science framework, "Getting to Outcomes®" (GTO), which incorporates continuous multilevel evaluation by stakeholders about the quality of the implementation. OBJECTIVES: (1) to obtain critical information on potential barriers to NBS in the disparate ethnic groups and settings (rural and urban) in the healthcare system of Kaduna State in Nigeria; and, (2) to assist in the readiness assessment of Kaduna in the implementation of a sustainable NBS programme for SCD. METHODS: Needs assessment was conducted with stakeholder focus groups for two days in Kaduna state, Nigeria, in November 2017. RESULTS: The two-day focus group workshop had a total of 52 participants. Asking and answering the 10 GTO accountability questions provided a structured format to understand strengths and weaknesses in implementation. For example, we found a major communication gap between policy-makers and user groups. CONCLUSION: In a two-day community engagement workshop, stakeholders worked successfully together to address SCD issues, to engage with each other, to share knowledge, and to prepare to build NBS for SCD in the existing healthcare system.

A novel 33-Gene targeted resequencing panel provides accurate, clinical-grade diagnosis and improves patient management for rare inherited anaemias.

Accurate diagnosis of rare inherited anaemias is challenging, requiring a series of complex and expensive laboratory tests. Targeted next-generation-sequencing (NGS) has been used to investigate these disorders, but the selection of genes on individual panels has been narrow and the validation strategies used have fallen short of the standards required for clinical use. Clinical-grade validation of negative results requires the test to distinguish between lack of adequate sequencing reads at the locations of known mutations and a real absence of mutations. To achieve a clinically-reliable diagnostic test and minimize false-negative results we developed an open-source tool (CoverMi) to accurately determine base-coverage and the 'discoverability' of known mutations for every sample. We validated our 33-gene panel using Sanger sequencing and microarray. Our panel demonstrated 100% specificity and 99·7% sensitivity. We then analysed 57 clinical samples: molecular diagnoses were made in 22/57 (38·6%), corresponding to 32 mutations of which 16 were new. In all cases, accurate molecular diagnosis had a positive impact on clinical management. Using a validated NGS-based platform for routine molecular diagnosis of previously undiagnosed congenital anaemias is feasible in a clinical diagnostic setting, improves precise diagnosis and enhances management and counselling of the patient and their family.

Cardiac iron overload in transfusion-dependent patients with myelodysplastic syndromes.

Transfusion-dependent myelodysplastic (MDS) patients are prone to iron overload. We evaluated 43 transfused MDS patients with T2* magnetic resonance imaging scans. 81% had liver and 16·8% cardiac iron overload. Liver R2* (1000/T2*), but not cardiac R2*, was correlated with number of units transfused (r=0·72, P<0·0001) and ferritin (r=0·53, P<0·0001). The area under the curve of a time-ferritin plot was found to be much greater in patients with cardiac iron loading (median 53·7x10(5) Megaunits vs. 12·2x10(5) Megaunits, P=0·002). HFE, HFE2, HAMP or SLC40A1 genotypes were not predictors of iron overload in these patients.

A novel scoring system combining expression of CD23, CD20, and CD38 with platelet count predicts for the presence of the t(11;14) translocation of mantle cell lymphoma.

BACKGROUND: Both chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL) are CD5/19 positive. The t(11;14) MCL translocation is identified by fluorescent in situ hybridization (FISH) and can distinguish the two disorders. We attempted to identify flow cytometric and other markers predictive of a positive FISH test. METHODS: We examined 100 atypical CLL/MCL cases for demographic, hematological, and cytometric variables, 96 were FISH tested for t(11;14) and four were known MCL. RESULTS: Twenty-two cases were confirmed as MCL. Multivariate analysis identified four variables associated with MCL: thrombocytopenia (taken as Plt < 150 × 109/L), CD23 negative, CD20 strong, and CD38 positive, with these variables a four-point score was devised. By ROC analysis, the MCL score was superior in differentiating MCL to the Marsden CLL score (AUC 0.95 vs. 0.78). MCL score ≥ 2 showed sensitivity 1, specificity 0.66, positive predictive value (PPV) 0.49, and negative predictive value (NPV) 1 for MCL. The score was then prospectively validated on an independent cohort of 44 cases of atypical CLL/MCL. No MCL had a score < 3. Validation PPV/NPV of score ≥ 3 were 0.5/1. Overall survival in MCL was shorter compared to t(11;14) negative patients (median 3.3 vs. 4.2 years, HR 2.2, 95% CI 0.87-5.5, P = 0.1). CONCLUSIONS: The score described can be used to identify cases of CD5/19 positive lymphoproliferative disorders likely to be t(11;14) positive MCL.

Clinical relevance of low serum vitamin B12 concentrations in older people: the Banbury B12 study.

BACKGROUND: low vitamin B12 concentrations are common in older people, but the clinical relevance of biochemical evidence of vitamin B12 deficiency in the absence of anaemia is uncertain. OBJECTIVE: to examine associations of cognitive impairment, depression and neuropathy with blood measurements of vitamin B12 and folate status in older people. DESIGN: cross-sectional study in general practice in Banbury, England. PARTICIPANTS: a total of 1,000 individuals aged 75 years or older living in the community. RESULTS: low vitamin B12 concentrations were identified in 13% of older people and were associated with memory impairment and depression. After adjustment for age, sex and smoking, individuals with vitamin B12 or holotranscobalamin (holoTC) in the bottom compared with top quartiles had a 2-fold risk (OR = 2.17; 95% CI 1.11-4.27) and a 3-fold risk (OR = 3.02; 95% CI 1.31-6.98) of cognitive impairment, respectively. Low vitamin B12 status was also associated with missing ankle tendon jerks but not with depression. Treatment with vitamin B12 for 3 months corrected the biochemical abnormalities but had no effect on any of the clinical measurements. CONCLUSIONS: low vitamin B12 concentrations are associated with cognitive impairment and missing ankle tendon jerks in older people in the absence of anaemia. Large-scale trials of vitamin B12 supplementation are required to assess the clinical significance of these associations.

Lymphoplasmacytoid lymphoma presenting as severe osteoporosis.

We report four cases presenting with severe osteoporosis which on further investigation were found to have an underlying lymphoplasmacytoid lymphoma (LPL). Common secondary causes of osteoporosis were excluded in each case. Three of the cases responded to treatment with a biphosphonate. As these lymphomas share some common pathological and clinical features with multiple myeloma (MM) an association with osteoporosis is likely to represent more than a coincidental finding. The incidence of osteoporosis occurring with LPL will become clearer if routine imaging is carried out in patients at presentation. Issues relating to the treatment of the osteoporosis as well as the lymphoma arise in patients that present in this way. Based on the model of bone disease in MM, correlating serum levels of osteoclast activating cytokines such as interleukin-1 (IL-1), interleukin-6 (IL-6), and tumour necrosis factor (TNF) with the actual finding of bone disease provides a basis for future research into the pathogenesis and management of bone disease in these rare forms of low grade non-Hodgkin's lymphoma.