Clinical and laboratory haematology最新文献

Audits of malaria diagnosis in the UK have revealed shortcomings. The use of recommended procedures should improve the standard of malaria diagnosis. Both thick and thin films should be examined. Thick films should be stained unfixed with a Giemsa or modified Field's stain. Thin films should be fixed and stained with a Giemsa or a Leishman stain. All films should be examined for an adequate period of time by two observers. In the case of P. falciparum infection parasites should be quantified. Microscopy may be supplemented by an immunological or fluorescence-based method. Slides from all cases in which a diagnosis of malaria is made should be sent to a reference centre for verification. Laboratories should participate in a relevant NEQAS scheme and should take steps to ensure that all those carrying out malaria diagnosis maintain their skills.

When studying autoantibody specificity by the indirect antiglobulin test with column agglutination techniques ether and xylene elution techniques result in haemoglobin stained eluates which give a red colouration to the gel or glass beads and do not allow the identification of positive reactions. Xylene eluates were incubated with commercially available group O-test red cell panels at 37 degrees C for 45 min in the wells of a microtitre plate in a 3:1 eluate:red cell ratio. After washing with normal saline, sensitized red cells, resuspended in low ionic strength solution (LISS), were applied onto the microtubes containing the antiglobulin serum and positive reactions were recorded after centrifugation. We studied the specificity of 35 autoantibody containing eluates from 12 patients with lymphoproliferative disorders (six having autoimmune haemolysis) and 23 HIV patients without autoimmune haemolysis. All patients had a gel or column positive (IgG) direct antiglobulin test while the tube direct antiglobulin test failed to show red cell bound IgG. We found a reactive indirect antiglobulin test in 20/23 eluates from HIV infected patients (with a panreactive specificity), in all patients with autoimmune haemolysis (one with anti-C, two with anti-E, one with anti-K and two with a panreactive specificity) and in all patients with positive direct antiglobulin test but without immune mediate haemolysis (in all cases with panreactive specificity). The method proposed is a promising tool for the study of the specificity of antibody containing haemoglobin stained eluates; in this study it allowed us to confirm that some HIV patients have specific binding of IgG on their RBC and to identify the specificity of tube test non-reactive eluates.

We present the case of a patient with classical protein C deficiency presenting with acute priapism during warfarinization for thrombophlebitis. Priapism is a well-recognized complication of a number of conditions including sickle cell disease and haematological malignancies, but to our knowledge it has not previously been reported in association with protein C deficiency. This case highlights the potential dangers of initiating oral anticoagulant therapy using conventional loading dose regimens in patients with protein C deficiency.

With increasing work-loads in anticoagulant clinics different methods of service delivery need evaluation. The quality of anticoagulant control achieved by a nurse-practitioner using a computer decision-support system (CDSS) was compared with that achieved by trainee doctors without CDSS. Eighty-one out-patients (group A, therapeutic range 2-3) and 96 out-patients (group B, therapeutic range 3-4.5) were randomized to management by a nurse-practitioner or by trainee doctors (clinicians). Thirty-seven patients in group A and 50 patients in group B were randomized to be managed by the nurse-practitioner. In group A, patients in the nurse-practitioner group spent a longer time in the therapeutic range than those in the clinician group (60.7% compared with 51.6%). Dose suggestion acceptance in the nurse-practitioner group (88%) was higher compared with agreement between the CDSS and the clinicians (60%). In group B, patients in the clinician group spent a slightly longer time in the therapeutic range (70% compared with 67.6%). Acceptance of dose suggestion was lower in the nurse-practitioner group (67%) compared with agreement between the CDSS and the clinicians (73%). In conclusion, the CDSS can improve the quality of control of warfarin therapy by a nurse-practitioner over that by trainee doctors for the therapeutic range 2-3. Similar quality of control is achieved for the therapeutic range 3-4.5. The CDSS may be used by nurse-practitioners to achieve safe and effective anticoagulation in hospital-based or out-reach anticoagulant clinics.

An open, single centre study was carried out to evaluate the accuracy of the Spuncrit (Micro Diagnostics, Bethlehem, PA, USA) infra-red analyser which can be used for near-patient testing to measure haematocrit and estimate haemoglobin concentration. The primary comparison was with the Sysmex NE1500 (Tao Medical) analyser situated in the main hospital laboratory. Secondary comparison was with the Ciba Corning 288 (Ciba Corning Diagnostics Ltd, Halstead, UK) blood gas analyser currently used for near-patient testing in the Northern General Hospital. A total of 217 samples from 50 patients was analysed. The Pearson's correlation coefficients for haematocrit and haemoglobin concentration between the Spuncrit and Sysmex NE1500 and between the Spuncrit and Ciba Corning 288 were all close, between 0.85 and 0.92. The method of Bland and Altman was used to assess agreement between the results of the Spuncrit and the Sysmex NE1500. The agreement for haematocrit was good with 2 SD of the Spuncrit results being between -5.66 and +4.42% of the measurement from the Sysmex NE1500. In conclusion, the Spuncrit haematocrit measurement agreed well with results from the central laboratory, but the estimated haemoglobin concentrations agreed less well and three reasons are discussed.

The Cell Dyn 3500 (CD 3500) Haematology Analyser (Abbott Diagnostics, Lane Cove, NSW, Australia) has been evaluated to determine the reliability of the differential and white cell suspect flagging in a population of patients with known haematological abnormalities. The evaluation included the assessment of white cell differential parameters in addition to sensitivity, specificity and efficiency of white cell suspect flagging. The study showed that the CD 3500 is an efficient and sensitive screening tool for detecting the presence of clinically significant white cell abnormalities. Generally, the Blast and Band flags demonstrated the highest level of false positive flagging (lowest sensitivity). The immature granulocyte flag was found to be an extremely reliable indicator of the presence of myelocytes, metamyelocytes and promyelocytes on the film. There was a 0.4% false negative rate where significant numbers of variant lymphocytes (> 10%) were not detected by the CD 3500 on flagging alone. When analyser flags and white cell scatter distribution are considered in combination with defined laboratory limits, all white cell suspect flags have acceptable sensitivity, specificity and efficiency rates.

We measured pretreatment serum levels of tumour necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) in 25 patients with myelodysplastic syndrome receiving recombinant human erythropoietin (rhEPO) at dosages up to 300 U/kg thrice weekly for 12 weeks. Both TNF-alpha and IL-1 beta levels were measured using commercially available enzyme-linked immunoassays. A complete response (CR) was defined as a rise in untransfused haemoglobin concentrations of at least 2 g/dl or a 100% decrease in RBC transfusion requirements over the treatment period; a partial response (PR) was an increase in untransfused haemoglobin values of 1-2 g/dl or a decrease in RBC transfusion requirements equal to or greater than 50%; no response (NR) was defined as a response less than a PR. After 12 weeks of rhEPO treatment, four patients showed a CR, five patients a PR, and 16 patients NR. Serum levels of both TNF-alpha (80.5 %/- 64.8 vs 8.1 +/- 4.2 ng/l, P < 0.001) and IL-1 beta (60.4 +/- 49.9 vs 8.9 +/- 4.7 ng/l, P < 0.001) were higher in MDS patients than in a group of 28 normal controls. Responders (CR + PR) showed significantly lower serum levels of TNF-alpha than non-responders (21.6 +/- 26.2 vs 106.3 +/- 60.8 ng/l, P < 0.001), whereas IL-1 beta concentrations between those who benefited from therapy and unresponsive cases were not significantly different (39.8 +/- 48.9 vs 73.4 +/- 48.2 ng/l, P = 0.120). It is noteworthy that TNF-alpha levels were within the normal range in all responsive patients but one, whereas all non-responders presented elevated cytokine concentrations. No relationship was found between TNF-alpha or IL-1 beta values and haemoglobin levels, transfusion requirement, serum EPO or ferritin concentrations. We conclude that pre-treatment TNF-alpha levels might help to select those MDS patients who are most likely to benefit from rhEPO treatment.

Combination chemotherapy has had a low impact on survival of blast crises in chronic myelogeneous leukaemia (CML) which may be due to drug resistance. This work attempted to correlate the clinical response and some experimental evidence for the MDR phenotype. Blast cells were positive for P-glycoprotein using APAAP assay. In vitro tests showed that etoposide was partially toxic to blast cells when used alone but had its toxicity increased by nearly sixfold when combined with cyclosporin A (CSA). The patient responded poorly to treatment with etoposide combined with mitoxantrone and high-dose ara-c. However, when etoposide was associated with CSA, this patient returned to the chronic phase reinforcing our in vitro studies. Because no serious toxicity was seen clinically, we are inclined to consider the circumvention protocol an useful strategy to treat blast crises of CML.

A 22-year-old female on chronic total parenteral nutrition for short bowel syndrome presented for investigation of pancytopaenia and hepatosplenomegaly. Bone marrow examination revealed an infiltrate of sea-blue histiocytes and cytochemistry confirmed these to be lipid laden macrophages. The total amount of fat in the feeding regimen was subsequently reduced, and there has been a partial haematological improvement. The occurrence of sea-blue histiocyte syndrome complicating the fat emulsion component of chronic total parenteral nutrition has been reported recently. To our knowledge this report is the first where reduction in the lipid content of the feeding regimem has resulted in an improvement in the degree of pancytopaenia.