Capture-based targeted sequencing using a T-cell control in myeloid malignancies and idiopathic cytopenias.

We report on a study of next-generation sequencing in 257 patients undergoing investigations for cytopenias. We sequenced bone marrow aspirates using a target enrichment panel comprising 82 genes and used T cells from paired blood as a control. One hundred and sixty patients had idiopathic cytopenias, 81 had myeloid malignancies and 16 had lymphoid malignancies or other diagnoses. Forty-seven of the 160 patients with idiopathic cytopenias had evidence of somatic pathogenic variants consistent with clonal cytopenias. Only 39 genes of the 82 tested were mutated in the 241 patients with either idiopathic cytopenias or myeloid neoplasms. We confirm that T cells can be used as a control to distinguish between germline and somatic variants. The use of paired analysis with a T-cell control significantly reduced the time molecular scientists spent reporting compared to unpaired analysis. We identified somatic variants of uncertain significance (VUS) in a higher proportion (24%) of patients with myeloid malignancies or clonal cytopenias compared to less than 2% of patients with non-clonal cytopenias. This suggests that somatic VUS are indicators of a clonal process. Lastly, we show that blood depleted of lymphocytes can be used in place of bone marrow as a source of material for sequencing.

Investigation and management of a raised serum ferritin.

Serum ferritin level is one of the most commonly requested investigations in both primary and secondary care. Whilst low serum ferritin levels invariably indicate reduced iron stores, raised serum ferritin levels can be due to multiple different aetiologies, including iron overload, inflammation, liver or renal disease, malignancy, and the recently described metabolic syndrome. A key test in the further investigation of an unexpected raised serum ferritin is the serum transferrin saturation. This guideline reviews the investigation and management of a raised serum ferritin level. The investigation and management of genetic haemochromatosis is not dealt with however and is the subject of a separate guideline.

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.

Diagnosis and management of anaemia of chronic disease: current status.

Anaemia of chronic disease is the second most common form of anaemia worldwide, and is seen in a variety of inflammatory, infective and malignant diseases. Functional iron deficiency is fundamental to the pathogenesis of the anaemia, and the polypeptide, hepcidin, plays a key role. Diagnosis may be difficult, but new automated red cell indices, algorithms for detection of functional iron deficiency, and assays for hepcidin levels are being developed. Management of the causative disease process will usually improve haemoglobin levels, but where this is not possible, erythropoietic stimulating agents are often used, although there are still concerns about potential adverse effects, especially thromboembolism. There is increasing evidence that supplemental iron given parenterally can safely overcome the functional iron deficiency. Inhibitors of hepcidin, and various inflammatory modulators show promise for the future.

Clonal diversity in the myeloproliferative neoplasms: independent origins of genetically distinct clones.

This study looked for clonal diversity in patients with a myeloproliferative neoplasm associated with more than one acquired genetic lesion. A tyrosine kinase mutation and a cytogenetic lesion were present in the same clone in six of seven patients. By contrast, the genetic lesions were present in separate clones in all six patients with two tyrosine kinase pathway mutations. Moreover, in two patients the clones were genetically unrelated by X-chromosome inactivation studies. These data demonstrated clonal diversity in a subset of patients with early stage haematopoietic malignancy and showed, for the first time, that such clones may arise independently.

An audit of post-splenectomy prophylaxis--are we following the guidelines?

INTRODUCTION: Asplenic individuals have major difficulties coping with specific infections (e.g. Streptococcus pneumoniae). This is an audit to look at a district general hospital's compliance with published guidelines for immunisations and antibiotic prophylaxis post-splenectomy. PATIENTS AND METHODS: A retrospective review of hospital records of consecutive splenectomy patients from January 1996 to March 2001. RESULTS: Of 76 patients, 72% were vaccinated (30/76 with pneumococcal, HIB and meningococcal vaccines, 15/76 with Pneumovax and HIB, 10/76 with Pneumovax only), 63% were discharged on prophylactic antibiotics, and 81% of surviving patients had adequate communication with the GP regarding splenectomy. Patients undergoing non-elective splenectomy were less likely to be vaccinated or receive prophylactic antibiotics when compared with elective splenectomy patients. CONCLUSIONS: Results are comparable with other published studies, but are still unsatisfactory for many splenectomy patients. Vaccination rates must be improved and more information given to patients and GPs to allow for appropriate follow-up care.