RESUMO
El déficit de piruvato quinasa es la segunda enzimopatía más frecuente y la principal causa de anemia hemolítica congénita crónica no esferocítica. Su prevalencia está infraestimada por la baja sospecha clínica de los casos leves, las dificultades del correcto diagnóstico enzimático y la gran variedad de diagnósticos diferenciales. Los avances en las técnicas moleculares están permitiendo mejorar notablemente el diagnóstico. El tratamiento continúa basado en soporte transfusional y esplenectomía, siendo necesarios la vigilancia y el tratamiento de la sobrecarga férrica en todos los pacientes, transfundidos o no. Actualmente el único tratamiento curativo es el trasplante alogénico de progenitores hematopoyéticos, indicado en los casos graves con donante idéntico. Las nuevas terapias farmacológicas y génicas parecen prometedoras. En este artículo, el Grupo Español de Eritropatología realiza una actualización de la situación actual de esta enfermedad, con especial atención a los métodos diagnósticos y a los tratamientos actuales y futuros. (AU)
Pyruvate kinase (PK) deficiency is the second most frequent enzymopathy and the most common cause of chronic hereditary non-spherocytic haemolytic anaemia. Its global prevalence is underestimated due to low clinical suspicion of mild cases, associated with difficulties in the performance and interpretation of PK enzymatic activity assays. With the advent of next generation sequencing techniques, a better diagnostic approach is achieved. Treatment remains based on red blood cell transfusions and splenectomy, with special attention to iron overload, not only in transfusion-dependent patients. Nowadays, allogeneic hematopoietic stem cell transplantation is the only curative treatment, recommended only in selected cases of severely affected patients with an HLA-identical donor. Novel pharmacological and gene therapies are in clinical trials, with promising results. In this article, the Spanish Erythropathology Group reviews the current situation of PK deficiency, paying special attention to the usefulness of different diagnostic techniques and to actual and emerging treatments. (AU)
Assuntos
Humanos , Anemia Hemolítica Congênita não Esferocítica/diagnóstico , Anemia Hemolítica Congênita não Esferocítica/genética , Consenso , Piruvato Quinase/deficiência , Piruvato Quinase/genéticaRESUMO
Pyruvate kinase (PK) deficiency is the second most frequent enzymopathy and the most common cause of chronic hereditary non-spherocytic haemolytic anaemia. Its global prevalence is underestimated due to low clinical suspicion of mild cases, associated with difficulties in the performance and interpretation of PK enzymatic activity assays. With the advent of next generation sequencing techniques, a better diagnostic approach is achieved. Treatment remains based on red blood cell transfusions and splenectomy, with special attention to iron overload, not only in transfusion-dependent patients. Nowadays, allogeneic hematopoietic stem cell transplantation is the only curative treatment, recommended only in selected cases of severely affected patients with an HLA-identical donor. Novel pharmacological and gene therapies are in clinical trials, with promising results. In this article, the Spanish Erythropathology Group reviews the current situation of PK deficiency, paying special attention to the usefulness of different diagnostic techniques and to actual and emerging treatments.
Assuntos
Anemia Hemolítica Congênita não Esferocítica , Erros Inatos do Metabolismo dos Piruvatos , Anemia Hemolítica Congênita não Esferocítica/diagnóstico , Anemia Hemolítica Congênita não Esferocítica/genética , Anemia Hemolítica Congênita não Esferocítica/terapia , Consenso , Humanos , Piruvato Quinase/deficiência , Piruvato Quinase/genética , Erros Inatos do Metabolismo dos Piruvatos/diagnóstico , Erros Inatos do Metabolismo dos Piruvatos/genética , Erros Inatos do Metabolismo dos Piruvatos/terapiaRESUMO
La levadura Saccharomyces cerevisiae es sensible a la insulina de mamíferos y actúa en el metabolismo de carbohidratos. Sin embargo, no hay estudios de su efecto en las enzimas glucolíticas de este microorganismo. Este trabajo demuestra que la insulina estimula la actividad de piruvato quinasa en S. cerevisiae durante su crecimiento en medio rico suplementado con glucosa y en condiciones aeróbicas. En la fase logarítmica temprana, la máxima estimulación sobre el control se observó en presencia de 3 µM de insulina (actividad específica: 701 U/mg proteína, 404% de estimulación; actividad absoluta: 1,73 U/10(6) células, 652% de estimulación), sugiriendo un efecto sobre la regulación de la expresión genética de la enzima. La presencia de 1,2-3 µM de la hormona estimuló en 51-68% la expresión de las proteínas citoplasmáticas y, a concentraciones mayores (4,5-9 µM), también estimuló en 25-32% la proliferación celular, indicando hiperplasia e hipertrofia celular de acuerdo a la concentración de la insulina en el medio. El efecto de la hormona disminuyó en la fase logarítmica tardía de crecimiento, sugiriendo un periodo de acción, posiblemente por un mecanismo regulatorio dependiente de nutrientes. Este sistema puede servir como modelo para estudiar muchos de los efectos moleculares de la insulina no conocidos aún.
Saccharomyces cerevisiae yeast is sensitive to mammals insulin and acts in carbohydrate metabolism. Nevertheless, there are no studies of its effects on the glycolytic enzymes of this microorganism. This study shows that insulin stimulates pyruvate kinase activity in S. cerevisae during its growth in rich glucose supplemented media, and under aerobic conditions. In the early logarithmic phase, the maximum stimulation over control was seen in presence of 3 µM insulin (specific activity: 701 U/mg protein, 404% stimulation; absolute activity: 1.73 U/10(6) cells, 652% stimulation), suggesting an effect over the regulation of the genetic expression of the enzyme. The presence of 1.2-3 µM of insulin stimulated the expression of cytoplasmic proteins in 51-68% and at higher concentrations (4.5-9 µM) it also stimulated cell proliferation in 25-32%, indicating cell hyperplasia and hypertrophy according to the hormone concentration in the medium. The effect of the insulin decreased in the late logarithmic growth phase, suggesting a period of action, possibly due to a nutrient dependent regulatory mechanism. This system can serve as model to study many of the molecular effects of insulin not yet known.
