Serum calcium is an independent prognostic factor of overall survival in Mexican patients with multiple myeloma.

OBJECTIVE: To evaluate the impact of different prognostic factors that has been suggested to be useful in predicting the survival of patients with multiple myeloma (MM). MATERIALS AND METHODS: A longitudinal prospective study was conducted on 24 adult Mexican patients diagnosed with primary MM. The levels of expression of CD38, CD138 and cyclin D1 were analyzed in plasma cells (PCs) from patients and mononuclear cells from healthy donors. Serum levels of lactate dehydrogenase, creatinine, calcium, beta2 microglobulin and interleukin-6 (IL-6) as well as hemoglobin and platelet count were taken into consideration. RESULTS; CD138 and cyclin D1 levels in absolute numbers were significantly overexpressed in malignant PCs. A positive correlation was noted between cyclin D1 and CD38 expression levels in malignant PCs. IL-6 and serum calcium were also positively correlated in MM patients. Cyclin D1 overexpression was not associated with better overall survival (OS). Normal calcium levels were associated with better overall survival (OS). Serum calcium was the only variable correlating with better OS in Cox regression analysis. CONCLUSION: Serum calcium is an independent prognostic factor of OS in a population of Mexican patients with MM.

Estudio ultraestructural de las plaquetas de pacientes con hemoglobinuria paroxística nocturna / Ultrastructural study of platelets patients with paroxysmal nocturnal hemoglobinuria

Introduction. Paroxysmal nocturnal hemoglobinuria (PNH) is a hemolytic anemia characterized by intravascular hemolysis, cytopenias and venous thrombosis. Previous studies in patients with PNH have shown platelet abnormalities; however, their association with the clinical development of the sickness has not still been determined. Material and methods. In this study, we compared the morphology and distribution pattern of actin, myosin, tubulin and p-selectin in resting and activated platelets from 22 PNH patients and healthy donors by transmission electron microscopy and immunofluorescence. Results. The PNH platelet ultrastructure of resting and activated with different agonists (ADP, collagen and thrombin) showed morphological changes which suggested the presence of circulating platelets. The developed structures during the adhesion process (filopodia and lamellipodia formation), as well as the pattern distribution of actin, myosin, tubulin and p-selectin in PNH platelets were not modified in relation to control platelets. Conclusion. Morphological changes in resting platelets were related with p-selectin expression suggesting its determination as thrombosis indicator.

Introducción. La hemoglobinuria paroxística nocturna (HPN) es una anemia hemolítica caracterizada por hemolisis intravascular, citopenias y trombosis venosa. Estudios previos en pacientes con HPN han revelado anormalidades plaquetarias; sin embargo, no se ha determinado su asociación con el desarrollo clínico de la enfermedad. Material y métodos. En el presente estudio se comparó la morfología y el patrón de distribución de actina, miosina, tubulina y P-selectina en plaquetas en reposo y activadas provenientes de 22 pacientes con HPN y de individuos sanos por microscopía electrónica de transmisión e inmunoñuorescencia. Resultados. La ultraestructura de las plaquetas de individuos con HPN en reposo y activadas en suspensión con diferentes agonistas (ADP, colágena y trombina) mostró cambios morfológicos que sugirieron la presencia de plaquetas activadas circulantes. Las estructuras desarrolladas durante el proceso de adhesión (formación de filopodios, lamelipodios), así como el patrón de distribución de actina, miosina, tubulina y P-selectina, no se modificaron en las plaquetas de los pacientes con HPN en relación con el testigo. Conclusión. Los cambios morfológicos en plaquetas en reposo fueron relacionados con la expresión de P-selectina, por lo que se sugiere su determinación como un parámetro indicativo de un posible riesgo trombótico.

[Ultrastructural study of platelets patients with paroxysmal nocturnal hemoglobinuria]. / Estudio ultraestructural de las plaquetas de pacientes con hemoglobinuria paroxística nocturna.

INTRODUCTION: Paroxysmal nocturnal hemoglobinuria (PNH) is a hemolytic anemia characterized by intravascular hemolysis, cytopenias and venous thrombosis. Previous studies in patients with PNH have shown platelet abnormalities; however, their association with the clinical development of the sickness has not still been determined. MATERIAL AND METHODS: In this study, we compared the morphology and distribution pattern of actin, myosin, tubulin and p-selectin in resting and activated platelets from 22 PNH patients and healthy donors by transmission electron microscopy and immunofluorescence. RESULTS: The PNH platelet ultrastructure of resting and activated with different agonists (ADP, collagen and thrombin) showed morphological changes which suggested the presence of circulating platelets. The developed structures during the adhesion process (filopodia and lamellipodia formation), as well as the pattern distribution of actin, myosin, tubulin and p-selectin in PNH platelets were not modified in relation to control platelets. CONCLUSION: Morphological changes in resting platelets were related with p-selectin expression suggesting its determination as thrombosis indicator.

Incidence of aplastic anemia in a defined subpopulation from Mexico City.

Aplastic anemia (AA) is a hematological disease characterized by the deficient production of blood cells. The incidence of AA worldwide is low (1-5 new cases per 10(6) individuals per year). In contrast to other countries, no current reports exist on the incidence of this disorder in Mexico. In the present study, we have determined the incidence of AA in a defined subpopulation from Mexico City during the period 1996-2000. For the purpose of this study, we focused on the experience from a single medical institution: the Mexican Institute of Social Security (IMSS), which covers around 50% of Mexico's population. The incidence of AA was determined based on the actual number of patients diagnosed with this disease at the IMSS in Mexico City in a given year and the total number of individuals registered at the IMSS in Mexico City in the same year. Considering the IMSS population as a whole, the annual incidence of AA was 3.9 new cases per 10(6) individuals per year. In the pediatric population, the annual incidence was 4.2 new cases per 10(6) individuals per year, whereas in people 15-years-old and older the incidence was 3.8 new cases per 10(6) individuals per year. These incidences were higher than those reported in most studies from the USA, Europe and Israel. Compared to the incidence in Thailand, the incidence we observed in children was considerably higher, whereas the one in adults was similar to the one in that country. The results of the present study suggest that the incidence of AA in Mexico City is one of the highest worldwide, particularly in terms of the pediatric population; however, these results must be taken with caution since this study comprises only a subpopulation from Mexico City and not the entire population. Thus, further studies including a broader population, both in Mexico City and other urban and rural areas of this country, will be necessary in order to obtain better and more complete estimates of the actual incidence of AA in Mexico.