RESUMEN
Calibration of laboratory apparatus is not sufficient to ensure accurate results. Application of the "random duplicates" method to the measurement of hemoglobin estimations and leukocyte counts by the Coulter Model S revealed unsuspected deficiencies in the laboratory operation. The resultant changes led to a significant improvement in the quality of work performed.
Asunto(s)
Hematología , Laboratorios/normas , Control de Calidad , Hemoglobinas , Recuento de LeucocitosRESUMEN
Since April 1975 the proficiency of laboratories in Ontario that perform immunohematology tests has been assessed. While the majority of test samples have required only ABO and Rh(D) typing, others have posed problems. The error rate in uncomplicated ABO typing was 1.3/1,000 in 17,479 tests and that in straightforward Rh(D) grouping, 6.6/1,000 in 17,757 tests. False-negative (36/1,000) and false-positive (1.4/1,000) direct antiglobulin tests occurred. Errors in detection of strong alloantibodies (e.g., anti-D) were 19.7, 10.2 and 5.1/1,000 in three test samples. A2B or A2 cells with anti-A1 in serum were sent out in two surveys; error rates in ABO interpretation were 189 and 52/1,000, respectively. Laboratories also experienced difficulty in interpreting the Rh(D) type of cells with positive antiglobulin tests. These surveys have had several effects: (1) laboratories with poor performance have been identified, (2) patterns of practice have been influenced, (3) areas of ignorance have been identified, and (4) a stimulus has been provided for continuing education in immunohematology.
Asunto(s)
Técnicas Inmunológicas/normas , Laboratorios/normas , Sistema del Grupo Sanguíneo ABO , Tipificación y Pruebas Cruzadas Sanguíneas , Prueba de Coombs , Reacciones Falso Negativas , Reacciones Falso Positivas , Humanos , Isoanticuerpos/análisis , Ontario , Sistema del Grupo Sanguíneo Rh-HrRESUMEN
Chronic myeloid leukemia consists of Philadelphia chromosome positive disease in 90% of cases, and a further 5%, although Philadelphia chromosome negative, exhibit bcr gene rearrangements consistent with the disease. The remaining 5% of cases have a heterogeneous clinical picture with a course unlike that of classical chronic myeloid leukemia, and may belong to different pathologic entities. We report five cases belonging to the latter group, initially identified as Philadelphia chromosome negative, bcr non-rearranged chronic myeloid leukemia, that developed progressive leucocytosis, absolute monocytosis, myelodysplasia, extramedullary hematopoiesis, and had evidence of myelofibrosis. These cases may represent a distinct clinical entity characterized by neutrophilic myelofibrosis, which can be identified prospectively by clinical and pathologic criteria. Standard therapy for treating chronic myeloid leukemia or idiopathic myelofibrosis may not be appropriate for this group.
Asunto(s)
Reordenamiento Génico/genética , Leucemia Mielógena Crónica BCR-ABL Positiva/diagnóstico , Neutrófilos/patología , Cromosoma Filadelfia , Mielofibrosis Primaria/diagnóstico , Adulto , Anciano , Aberraciones Cromosómicas , Mapeo Cromosómico , Cromosomas Humanos Par 22/ultraestructura , Clonación Molecular , Diagnóstico Diferencial , Humanos , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Masculino , Persona de Mediana Edad , Mielofibrosis Primaria/genética , Mielofibrosis Primaria/patologíaRESUMEN
Persistent polyclonal lymphocytosis has been described in a group of female patients who all have the HLA-DR7 antigen in common and who are all heavy cigarette smokers. Immunoglobulin heavy chain gene rearrangement was analyzed by hybridization with specific immunoglobulin heavy chain genes to restriction enzyme-digested genomic DNA samples. The results in two of these patients showed that the lymphocytosis was associated with an expanded subpopulation of B-lineage cells represented by the presence of an unusual immunoglobulin gene rearrangement pattern. Expansion of this subpopulation of B cells appeared to be linked to cigarette smoking since the intensity of the cell population harboring the rearranged gene was much stronger in patients who were smoking heavily compared with the same patients who were temporarily not smoking.
Asunto(s)
Linfocitos B , Reordenamiento Génico de Cadena Pesada de Linfocito B/inmunología , Antígeno HLA-DR7/genética , Linfocitosis/genética , Fumar/efectos adversos , ADN/inmunología , Femenino , HumanosRESUMEN
A compulsory programme of proficiency testing in immunohaematology has been conducted for the last 4 years. The collection, processing and analysis of testing data reported by participating laboratories depends on a computer-based system, which allows the generation of reports for participants and working documents essential to the functioning of a committee which supervises the operation of the programme. The options open to the committee in coping with laboratories with poor performance are summarized.
Asunto(s)
Antígenos de Grupos Sanguíneos , Laboratorios/normas , Estándares de Referencia , Sistema del Grupo Sanguíneo ABO , Anticuerpos , Computadores , Prueba de Coombs , Recolección de Datos , Errores Diagnósticos , Humanos , Sistema del Grupo Sanguíneo Rh-HrRESUMEN
An analysis of the results of a compulsory proficiency testing programme in immunohaematology is presented. Error rates have been calculated for the determination of ABO and Rh(D) groups, the direct antiglobulin test and antibody detection according to defined criteria. The introduction of proficiency testing has been associated with alterations in error rates for some determinations. An educational programme introduced for laboratories with poor performance has proved effective in improving their results in the proficiency testing programme.