Clinical and laboratory haematology最新文献

Two groups of blood samples, placental blood and female donor blood, were shown to have a frequency of 16.4 and 1.5% of anti-human leucocyte antigen (HLA) antibodies respectively. The specificities and qualities of these antibodies were further characterized by their relative coefficient (r) values and strength indices (SIs). Most had an r value of approximately one, but their SIs varied from 41 to 100%. Among these two groups, nine samples gave very strong and definite results (r = 1 and SI = 100%). Data analysis revealed that the qualities of the two groups were comparable. However, the antibody positive rate was higher in placental blood samples than that in donor blood samples.

A case of idiopathic myelofibrosis presenting with a pleural effusion secondary to extramedullary haemopoeisis is described. Approximately 2 years following the diagnosis of his myeloprolioferative disorder the patient presented with dyspnoea. Physical signs were consistent with a pleural effusion which was confirmed radiologically. Cytology of the effusion fluid demonstrated myeloid precursors, including megakaryocytes. The effusion required repeated draining and a pleurodesis was undertaken in an attempt to prevent reaccumulation of the fluid. The procedure was successful and follow up over a period of 5 months demonstrated no recurrence of the pleural effusion on that side of the chest. An effusion later occurred on the other side but was managed conservatively by drainage. Hydroxyurea was introduced at that stage, but shortly afterwards the patient died from an unrelated cause. We review the literature on this uncommon complication of myelofibrosis and discuss the options available to treat the disorder.

Thick film examination for malaria is often hampered by the presence of cellular debris obscuring parasites. This is a major problem for diagnostic laboratories that do not have a high exposure to material identification. Films that are relatively free of cellular debris, allowing easier identification of parasites are an obvious advantage. Saponin has been used by researchers to liberate malarial parasites for harvesting from infected erythrocytes. It has also been used for thick film preparations for diagnosis, but has not gained widespread acceptance, possibly due to the persistence of cellular debris inherent in the technique. In the present study the saponin method for thick film examination has been modified by the inclusion of a centrifugation step to remove cellular debris. Thick films were run in parallel with films made using the standard Fields stain technique and the original saponin. Results indicate that the modified saponin technique provides superior preparations free of cellular debris.

Very severe aplastic anaemia (vSAA) is rare. We report a case of Ecstasy-induced very severe aplastic anaemia which did not respond to immunosuppressive therapy, developing invasive pulmonary mucormycosis. The patient underwent an HLA-identical sibling peripheral blood progenitor cell transplant (PBPCT) with rapid neutrophil engraftment. During engraftment he developed life-threatening adult respiratory distress syndrome (ARDS). This case serves to illustrate a novel aetiology of vSAA where the infective complications responded to prompt haematopoietic engraftment.

Safe levels of anticoagulation are normally considered to be achieved if patients are maintained within their therapeutic international normalized ratio (INR) range for 70% or more time, but evidence in the United Kingdom suggests that this is often not attained. Recently, alternative models in the management of out-patient anticoagulation have been investigated with favourable results. We report on a study which compared a consultant anticoagulant service (CAS) with a nurse specialist service (NSAS). A sequential design was used with data collected on the consultant run service (CAS), followed by similar data on a NSAS over two 6 month periods. Two patient groups were recruited: those newly referred (group A) and those on long-term treatment (group B). Outcomes were the proportion of time patients spent within INR range, documentation of relevant clinical details, number of drugs taken which may adversely interact with and/or inhibit haemostatic function and patient knowledge. The results indicate that the NSAS was as good as the CAS in maintaining therapeutic control and better at documenting relevant clinical details in reducing the number of drugs taken which may adversely interact with and/or inhibit haemostatic function and in improving some aspects of patient knowledge.

A 14-year-old boy, with acquired haemolytic anaemia secondary to paravalvular leak from a prosthetic aortic valve, presented with severe pancytopenia. Subsequent investigation showed serological evidence of recent parvovirus B19 infection. The patient required transfusion and subsequently improved rapidly, with maintenance of pre-infective haemoglobin levels. To our knowledge this is the first reported case in which infection with parvovirus has caused pancytopenia in an acquired chronic mechanical haemolytic anaemia.

The move to the use of molecular diagnostics in medicine has gathered momentum in the last few years and new methodologies are being sought to reduce the labour component and hence the cost of these molecular diagnostics. A method is described which links PCR to capillary electrophoresis and this allows both a rapid and quantitative diagnosis. In the example provided, the diagnosis of chronic myeloid leukaemia, the method describes improvements in cost per test, greater sensitivity over traditional methods and an estimate of the level of product. The latter points are important in those disorders for which bone marrow transplantation is used as a curative regime in providing earlier detection of relapse.

The Abbott Cell Dyn 4000 (CD4000) is the first haematology analyser in which fully-automated reticulocyte measurements can be routinely determined by fluorescence as part of the full blood count. This communication reports the first evaluation of this method which was undertaken by three independent reference laboratories in Belgium, Germany and Italy. A total of 695 different samples was entered into the study which was designed to compare CD4000 reticulocyte information (enumeration and qualitative maturational data) with results determined in parallel with the existing manual (supravital staining) reference procedure, and two semi-automated fluorescent assays (Becton Dickinson FACScan and Sysmex R1000 instruments). These studies revealed good agreement between the CD4000 and the manual procedure, with no inter-method bias. Comparison of CD4000 and FACScan reticulocyte measurements, however, indicated a distinct tendency for the FACScan to give higher reticulocyte estimates than the CD4000. Finally, the comparison of the CD4000 with the Sysmex R1000 showed excellent agreement in the range 0-6% reticulocytes, although there was some inter-method bias in the higher range (> 15%). Analysis of agreement levels between the methods using specific 'clinical decision points' confirmed the tendency for overestimation by the FACScan, in that 58% of the samples with a reticulocytopenia of < 0.5% as defined by the CD4000 gave FACScan results within the normal range (0.5-1.8%). In contrast, there was absolute agreement between the CD4000 and the Sysmex R1000 for all reticulocytopenias. Comparison (195 samples) of instrument fluorescent reticulocyte maturation profiles demonstrated an exponential relationship (r = 0.78) between CD4000 IRF and R1000 HFR (highly fluorescent reticulocyte fraction) values. The suggestion that the CD4000 IRF values includes some of the MFR as well the HFR reticulocyte fraction was confirmed as the correlation between the CD4000 IRF and the Sysmex R1000 MFR plus HFR percentages was linear (r = 0.82). This study confirms a high performance level for the CD4000 automated fluorescent reticulocyte method.