Perfil lipídico en mujeres embarazadas sanas de tres regiones de Chile / Lipid profile in healthy pregnant women in three regions of Chile

Antecedentes: Los lípidos plasmáticos maternos durante el embarazo pueden influir en el crecimiento fetal, particularmente en pacientes con diabetes gestacional; estos lípidos cambian su concentración plasmática materna a lo largo de la gestación. Objetivo: Calcular tablas y curvas de lípidos normales según edad gestacional en una población de embarazadas chilenas. Método: Se midió el colesterol total (CT), colesterol LDL (LDL-C) triglicéridos (TG), Colesterol-HDL (HDL-C), y ácidos grasos no esterificados (NEFA), en 94 embarazadas sanas y jóvenes (<33 años, edad media de 27,6 +/- 6,2 años), con peso pregestacional normal (Índice de Masa Corporal entre 20 y 24,9 Kg/m2 y medio de 23,3 +/- 2,0 Kg/m2). Las pacientes provenían de: Hospital Parroquial de San Bernardo, Santiago (n=55), Hospital de Talca (n=2); Hospital del Profesor, Santiago (n=18); Hospital Regional de Concepción (n=9) y Hospital Clínico de la Pontificia Universidad Católica de Chile (n=10). Resultados: Calculamos, para cada uno de los cuatro lípidos, las curvas de percentil 50, percentil 90 y percentil 10, en mg/dL y mmol/l. Los NEFA solo fueron expresados en mmol/l. Incluimos las funciones matemáticas de las curvas de regresión polinomial de los cuatro lípidos con el fin que sean fácilmente reproducibles en otros tamaños. Conclusiones: Calculamos las tablas y curvas de lípidos maternos normales a lo largo del embarazo, que sean aplicables a la población de embarazadas chilenas.

Background: In normal human pregnancy, maternal lipids can modify the rate of fetal growth, particularly in pregnancies with Gestational Diabetes Mellitus (GDM). These lipids change continuously their serum concentration in the mother along the pregnancy. Aim: To calculate tables and curves of normal serum lipids, according to gestational age, in healthy Chilean pregnant women. Methods: We measured total cholesterol (CT), LDL-cholesterol (LDL-C), triglycerides (TG), HDL-Cholesterol (HDL-C), and Non-Esterified Fatty Acids (NEFA) in 94 young and healthy pregnant women (< 33 years, mean age 27.6 +/- 6.2 years), with normal pregestational Body Mass Index (BMI, 20.0-24.9 Kg/m2 , mean value= 23.3 +/- 2.0 Kg/m2). The women of the study were patients of 5 hospitals: Hospital Parroquial de San Bernardo, Santiago (n=55), Hospital de Talca (n=2); Hospital del Profesor, Santiago (n=18); Hospital Regional de Concepción (n=9) and Hospital Clínico de la Pontificia Universidad Católica de Chile (n=10). Results: For each one of the lipids, we calculated curves of 50th, 90th and 10th percentiles, both in mg/dL and mmol/L (the NEFA were expressed only in mmol/L). The mathematical functions of the curves of polynomial regression of all lipids were included in the manuscript, in order to facilitate their reproduction. Conclusions: We calculated tables and curves of normal maternal serum lipids in relation to gestational, in order to make these available for use in the care of Chilean pregnant women.

Plasmodium vivax: epitope mapping of monoclonal antibodies against the N-terminal region of the merozoite surface protein 1.

Plasmodium vivax is the most widely distributed human malaria with an estimate of 35 million cases per year. The deduced amino acid sequence comparisons of the Merozoite Surface Protein 1 (MSP1) from several plasmodial species, including that of P. vivax (PvMSP1), revealed the existence of highly conserved blocks and polymorphic blocks. We had previously shown that sequences within conserved blocks from the N-terminal region of the PvMSP1 were poorly immunogenic in natural human infections. These results suggest that these regions code for important and unknown structural and/or functional features and thus they could potentially be tested as a sub-unit PvMSP1 vaccine. In the present study, a battery of monoclonal antibodies (Mabs) was produced against the N-terminal region of the PvMSP1 in an attempt to determine whether these N-terminal ICBs contained all the epitopes exposed on the native molecule. The results suggest that the most terminal ICB2 and ICB3 blocks are not exposed on the surface of the PvMSP1 native molecule and clearly eliminate the possibility of considering the N-terminal domains as unique components of a sub-unit PvMSP1 vaccine candidate.

Plasmodium vivax: dimorphic DNA sequences from the MSP-1 gene code for regions that are immunogenic in natural infections.

The merozoite surface protein 1 gene of Plasmodium vivax (PvMSP-1) is becoming a solid genetic marker for studying the polymorphism of natural parasite populations from this prevalent human malaria. Indeed, a conserved and a variant PvMSP-1 gene segments have been amplified from total genomic parasite DNA obtained from isolates representing seven countries and three continents. Interestingly, the variant PvMSP-1 gene segment contains two highly conserved parental allele forms capable of limited genetic exchange at the sexual stage in the mosquito vector. This variant PvMSP-1 gene segment was amplified from 18 Colombian isolates to try to determine whether the same two parental allele forms were also present in this geographical area. Southern blot and DNA sequencing analyses confirmed their existence among the Colombian isolates. Moreover, expression of these two allele forms as recombinant proteins allowed us to demonstrate for the first time that this PvMSP-1 gene segment codes for amino acid sequences that are exposed on the surface of P. vivax schizonts and that are immunogenic in natural infections.

Characterization of naturally acquired human IgG responses against the N-terminal region of the merozoite surface protein 1 of Plasmodium vivax.

The primary structure of the merozoite surface protein 1 of Plasmodium vivax (PvMSP-1) revealed the existence of conserved and polymorphic blocks of the protein among different Plasmodium species. To characterize the naturally acquired IgG antibody responses to the PvMSP-1 molecule, the entire N-terminal portion of this protein was expressed as 10 overlapping glutathione S-transferase fusion proteins. The affinity-purified recombinant products were tested by enzyme-linked immunosorbent assay and Western blot against the sera of malaria patients from the state of Rondonia, Brazil. We found that the majority of these sera did not contain IgG antibodies recognizing recombinant proteins expressing exclusively interspecies conserved blocks of the molecule. In contrast, a high proportion of these same sera reacted against recombinant products expressing interspecies polymorphic regions of this protein. The poor B cell immunogenicity of the interspecies conserved blocks of the PvMSP-1 molecule most likely reflects important and unknown structural or functional features of these regions.

Longitudinal study of naturally acquired humoral immune responses against the merozoite surface protein 1 of Plasmodium vivax in patients from Rondonia, Brazil.

A longitudinal study on the naturally acquired humoral immune responses against the merozoite surface protein 1 of Plasmodium vivax (PvMSP-1) was performed in malaria patients from the Brazilian Amazon region of Rondonia. We have previously cloned and expressed a recombinant protein, ICB2-5, that encodes 508 amino acids from the N-terminal portion of the PvMSP-1 protein. This affinity-purified polypeptide was tested by an enzyme-linked immunosorbent assay in a one-year longitudinal study using sera from 34 patients who had at least one malaria infection during the study period. The results demonstrated that more than 90% of the sera from patients having experienced more than three previous malaria infections contained antibodies to ICB2-5 at the time of a new clinical episode. Unexpectedly, more than half of these multiple-infected patients had an antibody response to ICB2-5 in which the predominant isotype was IgM. In contrast, more than 83% of the sera from these same patients contained predominantly IgG antibodies against total blood-stage antigen preparations. To determine if these results were due to the lack of boosting against this portion of the PvMSP-1 molecule, the presence of IgG antibodies to ICB2-5 in the sera from 11 patients who had consecutive malarial episodes during the study year was investigated. Five of these eleven patients failed to produce IgG antibodies to ICB2-5 even after 1-3 infections. Thus, these results suggest that no boosting against this region of the PvMSP-1 molecule was achieved by natural infections among these patients.

Human IgG responses against the N-terminal region of the Merozoite Surface Protein 1 of Plasmodium vivax.

The complete primary structure of the gene encoding the Merozoite Surface Protein 1 of Plasmodium vivax (PvMSP-1) revealed the existence of interspecies conserved regions among the analogous proteins of other Plasmodia species. Here, three DNA recombinant clones expressing 50, 200 and 500 amino acids from the N-terminal region of the PvMSP-1 protein were used on ELISA and protein immunoblotting assays to look at the IgG antibody responses of malaria patients from the Brazilian amazon region of Rondônia. The results showed the existence of P. vivax and P. falciparum IgG antibodies directed against PvMSP-1 antigenic determinants expressed in the clones containing the first 200 and the following 500 amino acids of the molecule, but not within the one expressing the most N-terminal 50 amino acids. Interestingly, there was no correlation between the levels of these IgG antibodies and the previous number of malaria infections.