Rapid diagnosis of acute promyelocytic leukemia by analyzing the immunocytochemical pattern of the PML protein with the monoclonal antibody PG-M3

The fusion protein, promyelocytic leukemia-retinoic acid receptor (PML-RAR)alpha, generated by the t(15;17) translocation has an abnormal cellular distribution with colocalization of RARalpha and PML proteins. We analyzed the immunostaining pattern of PML protein using the PG-M3 monoclonal antibody directed against the amino terminal portion of PML (retained in wild-type PML and PML-RARalpha fusion protein) in the diagnosis of acute promyelocytic leukemia (APL). In addition, we compared this test with other methods for detecting the PML-RARalpha fusion gene. A normal immunostaining pattern was observed in nonmyeloid disorders and in 78 of 111 acute myeloid leukemias (AMLs). A microgranular pattern was observed in 25 AMLs, all corresponding to APL. These results were concordant with the reverse transcriptase-polymerase chain reaction results for PML-RARalpha fusion gene. Only 1 case positive for the PML-RARalpha transcript showed a normal protein pattern by immunocytochemistry. PML immunostaining was helpful to rapidly differentiate 7 cases with borderline characteristics and to obtain the diagnosis in 2 cases with scarce material. The effectiveness and low cost of this technique support its routine use as a first-line procedure in the differential diagnosis of AML.

[Use of diagnostic tests in the context of evidence-based medicine]

BACKGROUND

The advances of medicine over the last twenty years include the use of new tests and diagnostic methods in clinical practice. At the same time, we have witnessed the introduction of a strong movement, named Evidence Based Medicine, which basically includes a serious attempt for rationalizing the findings of more than 50 years of biomedical research, and to apply them properly to our patients as well as to the whole population.

METHODS

Review of the published literature. All the recommendations are used in a practical example.

RESULTS

Summary of the current existing recommendations for the assessment of a new diagnostic tool before its clinical application, and discussion of possible solutions for achieving a more efficient use of these tests.

CONCLUSIONS

There are enough evidences for defining criteria for a uniform evaluation process of new diagnostic tests. The criteria could be useful for the clinical application of these tests.

[The other side of the coin: socioeconomic analysis of antibiotic resistance]

BACKGROUND

The re-emergence of bacterial diseases and their negative consequences in terms of health and economic cost, have made this issue an important public health problem. The objective of this work is to review the economic literature about antibiotic resistance, and to suggest possible solutions in our health care context aimed to reduce their negative impact.

METHODS

We made a bibliographic search in the main biomedical databases. Economic assessment studies published in Spanish, English, French or Italian and related to the appearance of antibiotic resistance were selected. Their main methodological characteristics and results were analysed.

RESULTS

Two studies analysing the economic impact of the appearance of antibiotic resistance were identified. A minimum hospital cost of 1300 million dollars (in 1992), and a social cost between 100 and 30,000 million dollars (in 1989) were estimated.

CONCLUSIONS

Economic analysis allows to quantify and assess the impact of several management strategies in relation with antibiotic administration, in terms of health and costs, and to choose the most cost-effective strategies. The identification of inappropriate consumption of antibiotics as a cause of a negative externality upon the rest of the society is basic to make health care professionals and public opinion conscious about this problem, and to develop strategies to reduce its negative impact.

Anaplastic large-cell lymphoma with rapid evolution to leukemic phase

Anaplastic large-cell lymphoma (ALCL) is a lymphoproliferative disorder that frequently presents with disseminated disease and extranodal involvement. Rare atypical cells have been detected in the peripheral blood in occasional cases. However, the presence of a prominent leukemic phase is extremely rare in these patients. We describe a patient with a small-cell variant of ALCL of T-cell phenotype, ALK-1 positive, who developed a rapid leukemic phase in association with the progression of the disease. Similar to the nodal biopsy, the predominant cells in bone marrow and peripheral blood were small atypical lymphoid cells. The large tumor cells expressed ALK immunoreactivity with a cytoplasmic and nuclear pattern, whereas some of the small cells showed only a nuclear-restricted pattern of staining. An RT-PCR study detected the NPM-ALK chimeric product in the nodal biopsy and in a peripheral blood sample in the early phase of the disease, but it became negative in a peripheral blood sample obtained after completion of the chemotherapy treatment, suggesting that this assay may be useful in the follow-up of these patients. This case indicates that a prominent leukemic phase may develop in ALCL as a manifestation of tumor dissemination and that it may be composed of a predominant small-cell atypical component.

[Efficacy and safety of thrombolytic therapy in pulmonary embolism: meta-analysis of randomized controlled trials]

BACKGROUND

The role of thrombolytic agents in the treatment of pulmonary thromboembolism (PTE) remains a controversial issue. The objective of this study is to assess the efficacy and safety of thrombolytic therapy in the treatment of PTE by means of a meta-analysis of randomized controlled trials (RCT).

METHODS

A bibliographic search of the main biomedical bibliographic databases was carried out and eight randomized controlled trials that fulfilled the inclusion criteria were found. Two blinded and independent evaluators assessed the quality of RCT according to Jadad scale, and selected the necessary data to fulfill the objective of this study.

RESULTS

The selected trials were heterogeneous regarding the type of thrombolytic agent, the administration schedule, and the efficacy measures used. The methodological quality was 2 points in the Jadad scale as an average. No statistically significant differences in mortality nor in risk of PTE relapse were found between the group of patients receiving thrombolytic agents and the group not receiving them. Significant differences were found, however, between these two groups as regards the risk of bleeding events (OR = 2.62; CI 95%: 1.56-4.38).

CONCLUSION

The results of these meta-analyses do not suggest the use of thrombolytic therapy in PTE in everyday clinical practice since measurable risks overcome potential benefits.

Trade-offs in prenatal detection of Down syndrome

OBJECTIVES

This paper presents the results of different screening policies for prenatal detection of Down syndrome that would allow decision makers to make informed choices.

METHODS

A decision analysis model was built to compare 8 screening policies with regard to a selected set of outcome measures. Probabilities used in the analysis were obtained from official administrative data reports in Spain and Catalonia and from data published in the medical literature. Sensitivity analyses were carried out to test the robustness of screening policies' results to changes in uptake rates, diagnostic accuracy, and resources consumed.

RESULTS

Selected screening policies posed major trades-offs regarding detection rates, false-positive results, fetal loss, and costs of the programs. All outcome measures considered were found quite robust to changes in uptake rates. Sensitivity and specificity rates of screening tests were shown to be the most influential factors in the outcome measures considered.

CONCLUSIONS

The disclosed trade-offs emphasize the need to comprehensively inform decision makers about both positive and negative consequences of adopting one screening policy or another.

Two new mutations of the glucose-6-phosphate dehydrogenase (G6PD) gene associated with haemolytic anaemia: clinical, biochemical and molecular relationships

In two unrelated Spanish males with glucose-6-phosphate dehydrogenase (G6PD) deficiency and haemolytic anaemia, and two different novel point mutations in the G6PD gene, have been identified. A C to T transition at nucleotide 406 resulting in a (136) Arg to Cys substitution and a C to G transition at nucleotide 1155 resulting in a (385) Cys to Trp substitution. These two molecular defects have not been described before and are designated G6PD Valladolid 406 C-->T and G6PD Madrid 1155 C-->G. In vitro biochemical characterization of both mutant enzymes showed important differences in their molecular properties according to their different clinical behaviour. In G6PD Valladolid, the mutation of which is located in exon 5, the normal in vitro heat stability may explain its mild clinical expression (low-grade haemolysis interrupted by an acute haemolytic crisis at age 70). In G6PD Madrid, the mutation, located in exon 10, results in a deficient variant associated with neonatal jaundice and life-long chronic nonspherocytic haemolytic anaemia (CNSHA). This finding further emphasizes the importance of this specific region of the G6PD gene in the stabilization of the G6PD molecule. Putative relationships between these single point mutations and the molecular properties of the mutant enzymes are also discussed.

First description of a frameshift mutation in the alpha1-globin gene associated with alpha-thalassaemia

A frameshift mutation in the alpha1-globin gene, responsible for a clinically mild alpha-thalassaemia phenotype, has been characterized in a Spanish woman. After excluding the most common forms of alpha-thalassaemia found in the Mediterranean area, both alpha-globin genes (alpha1 and alpha2) were amplified and analysed selectively by non-radioactive single-strand conformation polymorphism (SSCP). An abnormal SSCP mobility was present in the second exon of the alpha1-globin gene and direct sequence analysis revealed a 13 bp deletion (between codons 51 and 55) affecting a single allele. The consequence of this mutation is a reading frameshift leading to a novel amino acid coding sequence from codons 51-61 and a premature stop signal at new position 62, which results in a net reduction of the affected alpha-globin chain output. The presence of this new mutation was confirmed by restriction enzyme analysis of the specific PCR product.

[Evaluation of the Coulter MAXM. Differential leukocyte count and left-shift alarm]

PURPOSE

To assess the reliability of the differential leucocyte count (DLC) and the left shift flagging (LSF) system provided by the Coulter MAXM (MAXM) haematology analyzer.

MATERIAL AND METHODS

380 blood specimens (drawn with tri-K EDTA as anticoagulant) were studied.

RESULTS

By using the reference method (NCCLS H20-A), 50 out of the 380 blood specimens presented abnormal DLC (bands > 6%). Of from these, in 39 (80%) the MAXM displayed LSF of "bands 1 or 2". In 118 left shift flagged specimens (MAXM) with normal manual DLC, 87 (74%) had the "bands 1" alarm and 31 (26%) the "bands 2" alarm. Accordingly if the LSF "bands 1" is overlooked, the percentage of FP decreases from 36% to 10% but the percentage of false negatives (FN) increases from 22% to 58%. In order to improve the appreciation of LSF by decreasing the need of manual revisions, the visual examination of the leucocyte distribution scattergram (LDS), also provided by the MAXM, was conveniently evaluated. This study was performed on 190 blood specimens from which the MAXM displayed a normal DLC in 122 (64%), the LSF of "bands" in 44 (23%) and the LSF of "bands 2" in 24 (12.6%). Of from the 122 specimens with normal DLC, four were FN, of from the 44 specimens with "bands 1" LSF, 37 were FP and of from the 24 specimens with "bands 2" LSF, 16 were FP. The visual appreciation of the LDS showed in the majority of samples with "bands 1" and "bands 2" a definitely different shape consisting in a sharper image up to the top of the picture when compared to samples with normal DLC (without flags). According to this criteria, all the 122 specimens with normal DLC displayed a normal LDS and all the 24 specimens with "bands 2" flag displayed abnormal LDS. Of from the 44 specimens with "bands 1" flag, 26 (59%) showed an abnormal LDS and 18 (41%) a normal LDS. It is noteworthy that of from the 26 specimens with abnormal LDS only 7 were true positive (TP), whereas the 18 specimens with normal LDS all showed a normal DLC according to the reference method. These data allow us to conclude that manual revision was required in 26 out of 68 specimens with "bands 1" and abnormal LDS (13% of the total) and in all the 24 specimens with "bands 2" flag. Therefore by using the information provided by the LDS the need of manual revision decreases to 73% of the total sample with LSF.

CONCLUSION

Our results give further support to the idea that th VCS method used by the Coulter MAXM provides a high quality DLC with specific left shift detection.

Congenital 6-phosphogluconate dehydrogenase (6PGD) deficiency associated with chronic hemolytic anemia in a Spanish family

Clinical and metabolic studies were performed in four members of a Spanish family with partial (50%) 6 phosphogluconate dehydrogenase (6PGD) deficiency. In all cases the activities of 6 phosphogluconolactone (6PGL) and glutathione reductase (GR) were normal, and the molecular characterization performed in the partially purified 6PGD from the propositus showed normal kinetic and electrophoretic patterns. Two females (the propositus and her sister) suffered from a well-compensated chronic nonspherocytic hemolytic anemia (CNSHA) and exhibited decreased RBC glutathione (GSH) stability with increased oxidative susceptibility, defined by enhanced malonyldialdehyde (MDA) generation "in vitro." The other two members of the family (the propositus's mother and brother) were clinically asymptomatic. In the propositus and her sister, RBC metabolism exhibited a markedly abnormal concentration of glycolytic intermediates, mainly characterized by striking increases in fructose 1,6 bisphosphate (50-fold), dihydroxiacetone-phosphate (20-fold) and glyceraldehyde 3-phosphate (tenfold). Although the precise mechanism of the hemolysis in the two patients is unknown, the enhanced oxidative threat observed in their RBCs may interfere in some way with the glycolytic pathway function, leading to a marked increase in certain metabolic intermediates located before the glyceraldehyde 3 phosphate dehydrogenase (GA3PD) step. Since it seems that GA3PD half-life is modulated by fluctuations of the cytosolic redox status, an "in situ" approach was simulated by using permeabilized RBCs. In these conditions, GA3PD activity was significantly lower in the propositus and her sister than in the asymptomatic members of the family and the simultaneous normal control.

Haemoglobin Lleida: a new alpha 2-globin variant (12 bp deletion) with mild thalassaemic phenotype

Molecular studies of alpha-thalassaemias have revealed defects at different steps in the process of alpha-gene expression. It is not surprising, therefore, that in some cases a single mutation or small deletion can result in a structurally abnormal haemoglobin that produces the alpha-thalassaemia phenotype. In this report we describe a new unstable alpha-globin variant, Hb Lleida, in a Spanish patient with alpha-thalassaemia trait. The mutation was detected by single-strand conformation polymorphism in the third exon of the alpha 2-globin gene. Direct sequence analysis of the alpha-globin gene showed a 12 bp deletion as the only defect of the alpha 2- and alpha 1-globin genes. The propositus was revealed to be a heterozygous carrier, and two alleles were separated by electrophoresis. This deletion causes the loss of four aminoacid residues (from codon 113 to 116) and would be expected to produce an unstable haemoglobin, as a shorter alpha-globin chain variant is created with 137 amino acids instead of 141 amino acids present in a normal alpha-globin chain. However, no abnormal haemoglobin was found by either isoelectric focusing or haemoglobin electrophoresis. Since the deletion affects an aminoacid residue (114 Pro) involved in alpha 1-beta 1-globin chain contacts, the interaction required for efficient Hb assembly is also compromised. The resulting unstable alpha-globin chain is rapidly catabolized and unsuitable for haemoglobin tetramer formation, causing an alpha-thalassaemia trait phenotype in the heterozygous patient.

Nondeletional alpha-thalassemia: first description of alpha Hph alpha and alpha Nco alpha mutations in a Spanish population

Several different deletions underlie the molecular basis of alpha-thalassemia. The most common alpha-thalassemia determinant in Spain is the rightward deletion (-alpha 3.7). To our knowledge, however, no cases of alpha-thalassemia due to nondeletional mutations have so far been described in this particular Mediterranean area. Here, we report the existence of nondeletional forms of alpha-thalassemia in ten Spanish families. The alpha 2-globin gene was characterized in ten unrelated patients and their relatives only when the presence of deletional alpha-thalassemia was ruled out. The alpha 2-globin gene analysis was performed using the polymerase chain reaction (PCR) followed by restriction enzyme analysis or by allelespecific priming. This allowed the identification of a 5-base pair (bp) deletion at the donor site of IVS I (alpha Hph alpha) in 9 cases and the alpha 2 initiation codon mutation (alpha Nco alpha) in one case. Although these alpha 2-globin gene mutations are found in other mediterranean areas, our results demonstrate their presence in the Spanish population and suggest that the alpha Hph alpha/alpha alpha genotype is probably the most common nondeletional form of alpha-thalassemia in Spain.

Hereditary xerocytosis: a report of six unrelated Spanish families with leaky red cell syndrome and increased heat stability of the erythrocyte membrane

Hereditary xerocytosis (HX) is a rare haemolytic disease due to dehydrated red blood cells (RBCs). A unique feature of this syndrome is that affected members often show normal or near normal haemoglobin levels despite clinical and laboratory evidence of mild to moderate haemolysis. The diagnostic clue is the association of markedly increased RBC Na+ + K+ fluxes with low total cation (Na+ + K+) content. 11 patients of six unrelated families of Spanish origin with HX have been studied from clinical, genetical and biological points of view. In addition, we have investigated the sensitivity of RBC membrane to heat at three different incubation times (15, 30 and 60 min) and two different temperature values (46 degrees C and 49 degrees C). Under these conditions control RBCs (50 normal subjects) exhibited at 49 degrees C and 30 min a maximum of 30% fragmented RBCs. This value increased to 80% after 60 min of incubation. In contrast, patients with HX showed significantly lower percentages of fragmented RBCs at both 30 and 60 min of incubation (maximum 10% and 30%, respectively). In an attempt to determine if increased heat stability was unique to HX RBCs, several other congenital membranopathies with haemolytic anaemia were also studied. The degree of fragmentation, except in one case of HPP (which was strongly increased), did not differ from the control group. Electrophoretic studies of membrane proteins performed in RBCs of all the patients with HX did not explain any qualitative nor quantitative abnormality. In addition to its physiopathological interest, study of RBC heat stability, together with other haematological parameters (increased MCHC and decreased RBC osmotic fragility), may be useful for HX diagnosis, especially in laboratories which are not equipped to evaluate RBC membrane permeability.

[Abnormal changes in erythrocyte membrane proteins in hereditary spherocytosis and their relation to clinical and biological aspects of the disease]

BACKGROUND

In the present paper we report a study of 20 patients with hereditary spherocytosis (HS) performed with the aim of provide further information on the electrophoretic abnormalities of red blood cell (RBC) membrane proteins and their putative relationship with the clinical, biological and genetic aspects of the disease.

METHODS

General hematological parameters, reticulocyte count, osmotic fragility test and erythrocyte morphology analysis, were performed by routine procedures. Membrane proteins of erythrocyte were analyzed by SDS-polyacrylamide gradient gel electrophoresis (SDS-PAGE) using the Laemmli and Fairbanks methods.

RESULTS

In 8 out of 20 cases (40%) a defect of band 3, alone or associated with a slight deficiency of protein 4.2, was observed. In addition to the presence of spherocytes, in all these 8 patients, a peculiar morphologic RBC alteration called pincered RBCs was also observed. Moreover, 2 cases showed a deficiency of protein 4.2, 2 cases a deficiency of ankyrin and 2 cases a deficiency of spectrin. In 6 cases (30%) the electrophoretical pattern of the erythrocyte membrane proteins was normal. A significant (r = -0.6; p < 0.01) correlation between the protein 4.2 (pallidin) and the mean corpuscular haemoglobin concentration (MCHC) was found. Also, the multiple regression analysis showed a correlation (r2 = 0.6; p < 0.0001) between the amount of protein 2.1 (ankyrin) and two hematological parameters: the mean corpuscular volume (MCV) and the red cell distribution width (RDW).

CONCLUSIONS

The defect of band 3 is the most frequent membrane protein abnormality associated with HS.

[Evaluation of the reproducibility of automated monocyte counting using flow cytometry and monoclonal antibodies]

PURPOSE

To compare the results of the monocyte count provided by autoanalysers with those attained with flow cytometry.

MATERIAL AND METHODS

Fifty-six blood samples (EDTA-K3) from the emergency laboratory were studied. The automatic percentage of monocytes attained by four autoanalysers, STKS (Coulter-IZASA), Technicon H*2 (Bayer Diagnostics), Cell-Dyn-3000 (Abbott Diagnostics) and NE-8000 (TOA-Sysmex) was confronted with that provided by the flow cytometry analysis performed with a FACScan (Becton-Dickinson) using monoclonal antibodies of myeloid-monocytic lineage (CD14, CD16). The morphologic observation of the blood smear in accordance with the H20-A protocol of the National Committee for Clinical Laboratory Standards (NCCLS) was used as a reference method. Descriptive statistics plus linear regression analysis, along with the Student's t test for paired data were used for the statistical evaluation of the results.

RESULTS

Significant correlation was found between the systems under study and the flow cytometry method: Technicon H*2 (y = 1.79 +/- 0.61x; r = 0.91, p < 0.0001), Coulter STKS (y = 0.61 +/- 0.93X; r = 0.89, p < 0.0001), Cell-Dyn 3000 (y = 0.88 + 0.64x; r = 0.78, p < 0.0001) and Sysmex NE-8000 (y = 4.60 +/- 0.33x; r = 0.52, p < 0.0001). When comparing the percentage of monocytes by means of the Student's t test it was found that Coulter STKS provided the closest results with regard to flow cytometry (13.78 +/- 9.27 vs 14.19 +/- 8.88, p = 0.49), while the closest findings with respect to the reference method were given by Technicon H*2 (9.29 +/- 4.78 vs 9.71 +/- 4.77, p = 0.30).

CONCLUSIONS

From this analysis, it was concluded that flow cytometry could be an alternative method to conventional optic observation in the evaluation of the differential count of leucocytes, including monocytes.

[Diagnosis of paroxysmal nocturnal hemoglobinuria with cytofluorometric of molecules bound to the membrane by glycosylphosphatidylinositol groups]

BACKGROUND

Paroxysmal nocturnal hemoglobinuria (NPH) is a clonal disease in which a deficit in the expression of molecules bound to the cell membrane by glycosyl-phosphatidylinositol (MUGFI) groups has been demonstrated. The MUGFI are widely distributed and among them proteins regulating the action of complement may be found. The development of monoclonal antibodies (MoAb) against MUGFI may allow the introduction of a new diagnostic method in this disease and increase the sensitivity, particularly in transfused individuals.

METHODS

The erythrocytic and leukocytic phenotype of 14 patients with NPH clonality demonstrated by the classic tests of sensitivity to the complement was analyzed by immunofluorescence techniques and flow cytometry with the use of MoAb which recognize MUGFI (CD55, CD59, CD14, CD16 and CD24).

RESULTS

Cells with a decrease or absence of MUGFI were observed in all the patients. The defect was demonstrated in the red cells, monocytes and neutrophils of all the patients, while it was only observed in the lymphocytes of three patients. The percentage of cells with a decrease in MUGFI was variable (2-100%) as well the pattern of deficiency against the different MoAb used. The MoAb with greatest sensitivity for the detection of clonal population were the CD59 in erythrocytes, the CD14 in monocytes and the CD24 in neutrophils. The CD16 was normal in one patient and the CD55 in two. The transfusion of packed red cells did not influence the abnormal leukocyte pattern, with abnormalities even being observed in the erythrocytary CD59. The Ham test was negative in those cases in which the percentage of negative CD59 erythrocytes was lower than 5% of the total erythrocytic population.

CONCLUSIONS

The study of glucosylphosphatidylinositol by flow cytometry and monoclonal antibodies is a useful technique for the detection and quantification of the nocturnal paroxistic hemoglobinuria clone even in transfused patients.

[Identification of molecular variants of the enzyme glucose-6-phosphate dehydrogenase by the polymerase chain reaction technique]

BACKGROUND

An assessment of the usefulness of polymerase chain reaction (PCR) in the identification of the most frequent molecular variants of the glucose-6-phosphate dehydrogenase (G6PD) in Spain: G6PD A-, G6PD Mediterranean and G6PD Seattle through the screening of the mutations: 376 A-->G; 202 G-->A; 680 G-->T; 968 T-->C; 563 C-->T and 844 G-->C.

METHODS

Three groups of patients have been studied: 1) males (40 cases); 2) relatives from the preceding group (31 cases: 7 males and 24 females), and 3) samples classified according to their fast electrophoretic mobility as G6PD A-(17 cases). The method used has been the PCR followed by digestion with specific restriction endonucleases.

RESULTS

Group 1: 23 out of 40 samples (57%), were identified as G6PD Med563T variant (8 cases), G6PD A-376G/202A (13 cases) and G6PD Seattle844C (2 cases). Group 2: The study of relatives from 13 of the 23 identified samples allowed the study of additional 31 samples (7 males, 24 females): hemizygous G6PD Med563T (3 cases), heterozygous GdB/Gd Med563T (5 cases), hemizygous G6PD A-376G/202A (4 cases), heterozygous GdB/Gd A-376G/202A (11 cases), heterozygous GdB/Gd Seattle844C (1 case) and normal females (7 cases). Group 3: In all electrophoretically fast samples classified as G6PD A-was detected the 376 A-->G mutation (characteristic of G6PD A+). In 15 of these cases a second mutation was found at nucleotide 202 G-->A (G6PD A-376G/202A); and in two, at nucleotide 968 T-->C (G6PD A-376G/968C).

CONCLUSIONS

The PCR method is fast and simple enough to allow the identification of known G6PD deficient variant, avoiding the need of its molecular characterization, which is more cumbersome and time consuming. In addition, the PCR is a very useful tool for demonstrating the carrier condition of G6PD deficiency in females with enzyme activity within normal range.

Elliptopoikilocytosis associated with the alpha 469 His-->Pro mutation in spectrin Barcelona (alpha I/50-46b)

We present two Spanish children with hereditary elliptopoikilocytosis. The mother displayed a symptomless elliptocytosis. Spectrin maps showed the alpha I/50-46b abnormality in the mother and in the children. The change was more conspicuous in the children than in the mother. The father carried the alpha V/41 allele, which is a common allele endowed with low expression. The alpha V/41 allele was also present in the children accounting for the much more severe expression of the alpha I/50-46b variant. The responsible mutation yielding the latter appeared to be the alpha 469 His-->Pro substitution (CAT-->CCT), which is a novel abnormality. The corresponding spectrin was designated spectrin Barcelona. As is often the case in hereditary elliptocytosis or poikilocytosis related to alpha-spectrin variants, the change involved a helix 3; namely, helix 3 of repeating segment alpha 5.

[Evaluation of the Sysmex NE-8000 analyzer according to the norms of the International Committee for Standardization in Hematology]

The Sysmex NE-8000 blood autoanalyser determines the values of red cells and platelets by impedance method and the differential leucocyte count (DLC) by means of radiofrequency plus two independent channels for eosinophils and basophils. The system is provided with a sampler capable of holding 100 closed tubes and its working velocity is about 120 samples per hour. The results of its evaluation are presented in this report. The parameters systematically provided by this cell counter include blood cell counts (plus haemoglobin rate, haematocrit and red cell indices), DLC platelet indices and volumetric distribution curves of red cells and platelets. The machine is provided with alarms on each of the above parameters for any suspicion of pathology. The accuracy analysis was performed with regard to the Technicon H*1 system and the conventional methods recommended by the ICSH. Precision, carry-over, linearity and effective velocity were evaluated in accordance to ICSH standards, and when assessing the DLC the number of visual revisions and the percentage of false positives and negatives were taken into account, and hence the sensitivity, specificity and efficiency of the machine. The accuracy of the parameters analysed was acceptable, except for MCHC and monocyte and eosinophil counts. A fair precision was found except for the monocyte count, along with excellent linearity except for high white-cell count. Less than 1.5% carry-over was observed, except for the leucocyte count. The number of necessary revisions of the DLC was somewhat higher than expected, the false negatives being below 11%. Sensitivity, specificity and efficiency were over 75%, except for hospital patients.(ABSTRACT TRUNCATED AT 250 WORDS)

[Initial evaluation of the Technicon H*2 blood analyzer: speed and quality of results]

The major differences of the autoanalyser Technicon H*2 with regard to the H*1, booth manufactured by the same firm, are the former's higher working speed, over one hundred samples per hour, its hydraulic changes and a new type of samples. This system provides cell counts, leucocyte differential count (LDC) and distribution graphs for cell volume, haemoglobin, platelets and leucocytes. Its accuracy was studied with regard to H*1 and reference methods, along with the precision, linearity, carry-over, necessary LDC revisions and LDC sensitivity, specificity and efficiency. Very good accuracy (r greater than 0.9) was found when except comparing H*2 with the other machine and the reference methods, except for MCHCH and basophil count. The linearity of results was good (r greater than 0.998) and the percentage of carry-over was less than 5% in all cases. Twenty one per cent of hospital patients (HP) and 8% of outpatients (OP) needed revision of LDC. False negative LDC appeared in 0.4% of HP and in 0.3% of OP. LDC sensitivity, specificity in H*2 have solved the problems of H*1, improving the performances and working velocity of the system.