RESUMEN
The 19-kDa C-terminal region of merozoite surface protein 1 (MSP1(19)), a major blood stage malaria vaccine candidate, is the target of cellular and humoral immune responses in humans naturally infected with Plasmodium falciparum. We have previously described engineered variants of this protein, designed to be better vaccine candidates, but the human immune response to these proteins has not been characterized fully. Here we have investigated the antigenicity of one such variant compared to wild-type MSP1(19)-derived protein and peptides. Gambian adults produced both high T helper type 1 (Th1) [interferon (IFN)-γ] and Th0/Th2 [interleukin (IL)-13 and sCD30] responses to the wild-type MSP1(19) and the modified protein as wells as to peptides derived from both forms. Response to the modified MSP1(19) (with three amino acid substitutions: Glu27Tyr, Leu31Arg and Glu43Leu) relative to the wild-type, included higher IFN-γ production. Interestingly, some peptides evoked different patterns of cytokine responses. Modified peptides induced higher IL-13 production than the wild-type, while the conserved peptides P16 and P19 induced the highest IFN-γ and IL-13 and/or sCD30 release, respectively. We identified P16 as the immunodominant peptide that was recognized by cells from 63% of the study population, and not restricted to any particular human leucocyte antigen D-related (HLA-DR) type. These findings provide new and very useful information for future vaccine development and formulation as well as potential Th1/Th2 immunmodulation using either wild-type or modified protein in combination with their peptides.
Asunto(s)
Interferón gamma/biosíntesis , Vacunas contra la Malaria/inmunología , Malaria Falciparum/inmunología , Malaria Falciparum/prevención & control , Proteína 1 de Superficie de Merozoito/genética , Proteína 1 de Superficie de Merozoito/inmunología , Plasmodium falciparum/inmunología , Antígenos de Protozoos/inmunología , Linfocitos T CD4-Positivos/inmunología , Citocinas/biosíntesis , Citocinas/sangre , Citocinas/inmunología , Gambia , Antígenos HLA-DR/análisis , Antígenos HLA-DR/inmunología , Humanos , Interferón gamma/sangre , Interferón gamma/inmunología , Interleucina-13/biosíntesis , Interleucina-13/sangre , Interleucina-13/inmunología , Antígeno Ki-1/biosíntesis , Antígeno Ki-1/sangre , Antígeno Ki-1/inmunología , Plasmodium falciparum/citología , Plasmodium falciparum/genética , Proteínas Protozoarias/inmunología , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/farmacología , Células TH1/inmunología , Balance Th1 - Th2 , Células Th2/inmunología , Vacunas Sintéticas/inmunologíaRESUMEN
STUDY OBJECTIVES: The aim of this pilot study was to investigate the use of viral genome diagnosis of HIV-1 infection in blood donors in the regional blood transfusion center in Ouagadougou, Burkina Faso. METHODOLOGY: This prospective study was carried out from August to December 2009 at the regional blood transfusion center in Ouagadougou (RBTC-O). Detection of HIV-1 was performed by RT-PCR on pooled plasma and individual samples from blood donors. Samples were selected based on reactivity with fourth generation ELISA. RESULTS: ELISA assays on 20 plasma pools demonstrated 10 negative samples, 8 positive and 2 undeterminable. All positive and negative ELISA tests were confirmed by RT-PCR. Findings of RT-PCR on individual samples confirmed those obtained on pooled plasma samples. For the two undeterminable pools, RT-PCR identified one as negative and the other as positive. Individual RT-PCR testing of donations contained in positive and negative pooled plasma samples confirmed negative or positive findings. CONCLUSIONS: Because of the high cost of RT-PCR, we recommend use first on minipools or individual samples from blood donors with questionable HIV-1 status to confirm status quickly and minimize loss of blood bags.
Asunto(s)
Donantes de Sangre , Transfusión Sanguínea , Infecciones por VIH/diagnóstico , VIH-1/genética , Plasma/virología , Adolescente , Adulto , Burkina Faso/epidemiología , Ensayo de Inmunoadsorción Enzimática , Femenino , Infecciones por VIH/epidemiología , Infecciones por VIH/genética , Infecciones por VIH/virología , Hospitales de Enseñanza , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Estudios Prospectivos , ARN Viral/sangre , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Estudios SeroepidemiológicosRESUMEN
Placental malaria infection affects the T helper type 1 (Th1)/Th2 balance in neonatal children. We investigated a potential role of regulatory T cells in this balance by comparing T cell responses of cord blood mononuclear cells (CBMC) from parasitized and non-parasitized placenta of Gambian women. CBMC were depleted of CD4(+)CD25(+) forkhead box P3 (FoxP3)(+) regulatory T cells and analysed in vitro for their ability to produce interferon (IFN)-gamma, sCD30 and interleukin (IL)-10 in response to phytohaemagglutinin (PHA), live Plasmodium falciparum, schizont extracts and the recombinant P. falciparum blood stage antigen merozoite surface protein 1 (MSP1(19)). As expected, lower IFN-gamma and higher sCD30 responses were observed for the cells from the parasitized group. In addition, higher IL-10 levels were produced by CBMC from the parasitized group. Depletion of regulatory T cells decreased IL-10 production, which resulted in a restoration of IFN-gamma expression in response to all stimuli. The Th2 marker sCD30 remained significantly higher in the parasitized group in response to malaria protein antigens while similar levels were recovered between both groups in response to live P. falciparum. Similar effects were observed by adding an antibody that blocks IL-10 function. These results suggest that the impact of P. falciparum infection on Th1 differentiation of neonatal T cells can be ascribed to regulatory T cells through production of IL-10.
Asunto(s)
Recién Nacido/inmunología , Malaria Falciparum/inmunología , Enfermedades Placentarias/inmunología , Complicaciones Parasitarias del Embarazo/inmunología , Subgrupos de Linfocitos T/inmunología , Antígenos de Protozoos/inmunología , Células Cultivadas , Femenino , Sangre Fetal/inmunología , Factores de Transcripción Forkhead/sangre , Humanos , Interferón gamma/biosíntesis , Interleucina-10/biosíntesis , Enfermedades Placentarias/parasitología , Plasmodium falciparum/inmunología , Embarazo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Linfocitos T Reguladores/inmunología , Células TH1/inmunología , Células Th2/inmunologíaRESUMEN
Although, HIV-2 is generally less pathogenic than HIV-1 and its progression towards AIDS occurs less frequently. HIV-2 remains an important cause of disease in West Africa. This study aimed to evaluate HIV-1 and HIV-2 prevalence among pregnant women and to describe the demographic and clinical profile of patients with HIV-2 infection from 2003-2013 at St Camille and General Lamizana Military Medical Centers. A retrospective investigation was conducted using 12,287 medical records from patients screened for HIV. To respond to the lack of data available regarding HIV-2 treatment and also to address the approach to clinical, biological as well as therapeutic monitoring, 62 HIV-2 infected patients' medical records were studied. Seroprevalence of 10.6 and 0.14% were obtained, respectively for HIV-1 and HIV-2 among 12,287 women screened during the study period. From the sixty two (62) HIV-2 patients, the average age was 49.2 years (sex ratio was 0.65). The weight loss and diarrhea were the major clinical manifestations observed, respectively 54.8 and 25.8%. Fungi and herpes zoster (shingles) infections were reported as major opportunistic infections. Also, nearly half of the patients had more than 60 kg, less than 2% were in WHO stage IV and about 2/3 had a CD4 count bellow 250 cells mm(-3). AZT-3TC-IDV/LPV/R was the most prescribed combination. The gain in weight gain the Body Mass Index (BMI) improvement and the non-significant increase of the rate of CD4 between 1st (M1) and 24th month (M24) were observed after treatment with antiviral.
Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Monitoreo de Drogas , Infecciones por VIH/tratamiento farmacológico , VIH-2/efectos de los fármacos , Hospitales Militares , Huésped Inmunocomprometido , Adulto , Burkina Faso/epidemiología , Recuento de Linfocito CD4 , Progresión de la Enfermedad , Monitoreo de Drogas/métodos , Quimioterapia Combinada , Femenino , Estudios de Seguimiento , Infecciones por VIH/diagnóstico , Infecciones por VIH/epidemiología , Infecciones por VIH/inmunología , Infecciones por VIH/transmisión , Infecciones por VIH/virología , Seroprevalencia de VIH , VIH-1/efectos de los fármacos , VIH-1/inmunología , VIH-1/patogenicidad , VIH-2/inmunología , VIH-2/patogenicidad , Humanos , Masculino , Persona de Mediana Edad , Infecciones Oportunistas/epidemiología , Infecciones Oportunistas/inmunología , Infecciones Oportunistas/virología , Embarazo , Prevalencia , Estudios Retrospectivos , Factores de Tiempo , Resultado del Tratamiento , Aumento de Peso/efectos de los fármacosRESUMEN
STUDY OBJECTIVES: The aim of this pilot study was to evaluate the use of real-time polymerase chain reaction (RT-PCR) in the diagnosis of bacterial meningitis in Burkina Faso. METHODOLOGY: This retrospective study reviewed the analyses of specimens collected from April 2009 through February 2010. DNA was extracted from cerebrospinal fluid (CSF) from patients with suspected meningitis from different health districts in Burkina Faso and analyzed with RT-PCR. Many patients were also tested with traditional diagnostic methods for meningitis: culture and serology (latex agglutination test). RESULTS: The study included 171 patients hospitalized in 8 health districts. Bacterial DNA for germs causing purulent meningitis was identified in 108/171 patients (63%); corresponding percentages for culture and latex were 60% (56/93) and 77% (66/86), respectively. All three methods found that NmA and Spn were the two main bacteria responsible for purulent meningitis in our cohort: with real time PCR, NmA = 59.3% and Spn = 34.3%), culture (NmA = 78.6% and Spn = 17.8%) or latex (NmA = 77.3% and Spn = 21.2%). Real-time PCR improved the sensitivity and the specificity of the diagnosis of the germs involved in this study and allowed the detection of the serogroups NmY and NmW135, which could not be detected by culture or latex agglutination test. RT-PCR permitted the detection and the characterization of bacteria responsible for purulent meningitis from CSF-contaminated cultures that could not otherwise be detected.
Asunto(s)
Meningitis Bacterianas/diagnóstico , Reacción en Cadena en Tiempo Real de la Polimerasa , Burkina Faso , Humanos , Técnicas de Diagnóstico Molecular , Proyectos Piloto , Estudios RetrospectivosRESUMEN
HCV and HBV cause annually, 2000 deaths from liver cancer in Burkina Faso. In this country, serological screening of hepatitis viruses B and C is only systematic among blood donors. The aims of this study were; (1) to investigate the reasons for the prescription of the screening for hepatitis B and C; (2) to determine HCV and HBV prevalence among 462 patients attending the Saint Camille Centre and (3) to identify patients with acute hepatitis or with chronic hepatitis for better monitoring. From February to May 2012, 462 patients attending the laboratory of the Saint Camille Medical Centre with viral hepatitis suspicion were screened. The hepatitis B and C serological markers were detected through Enzyme Immuno Assay (EIA) technique using commercial reagent kits. The clinical symptoms were also recorded for each patient. The results revealed that, the main clinical symptoms that prompted physicians to request HBV and HCV screenings were: asthenia (39.4%), anorexia (21.2%), abdominal pains (19.0%), nausea (10.4%), others (10.0%). The prevalence of HbsAg was 29.4% among the screened people. Patients with acute hepatitis B, active chronic hepatitis B and non-active chronic hepatitis B represented 11.2, 2.2 and 16.0%, respectively. The acquisition of immunity against HBV after vaccination was attempted for 11.7% people. HCV prevalence was 3.9% and its coinfection with HBV was 2.2%. This study showed a high prevalence for hepatitis B and C among patients attending Saint Camille Medical Centre. Without hygiene education and HBV/HCV prevention, viral hepatitis infection will become a serious public health problem in Burkina Faso.
Asunto(s)
Biomarcadores/sangre , Hepacivirus/aislamiento & purificación , Virus de la Hepatitis B/aislamiento & purificación , Hepatitis B/epidemiología , Hepatitis C/epidemiología , Adolescente , Adulto , Anciano , Instituciones de Atención Ambulatoria , Burkina Faso/epidemiología , Niño , Preescolar , Femenino , Hepatitis B/virología , Hepatitis C/virología , Humanos , Técnicas para Inmunoenzimas , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
BACKGROUND: Approximately, 15-20 of 40 HPVs that infect the female genital tract confer a high-risk of invasive cancer, thus HPVs account for 95% of cervix cancers. The objectives of this study were to: (i) estimate the prevalence of HPV infection in women infected with HIV in Ouagadougou, (ii) identify potential carcinogenic HPV strains and (iii) determine whether existing HPV vaccines match the isolated strains. METHODS: From May 2009 to April 2010, 250 HIV-infected women were included in this study. Each woman was screened for the presence of HPV and for HPV genotype using PCR/hybridization technique. RESULTS: Of the 250 HIV-infected women, 59.6% were infected with at least one type of HPV. High-risk HPVs were identified with the following prevalence: HPV-18 (25.0%); HPV-50'S (25.5%); HPV-30'S (20.8%); HPV-16 (4.7%); HPV-45 (3.7%). Low-risk HPVs were represented by HPV-6 (5.7%) and HPV-11 (0.9%). CONCLUSION: The issue of the study showed that the existing vaccines: Gardasil and Cervarix may be used in the country although they match only HPV-16, HPV-18, HPV-6 and HPV-11. Further investigations should be continued for the establishment of vaccine that matches all genotypes circulating in the country.
Asunto(s)
Dermatoglifia del ADN , Papillomaviridae/clasificación , Papillomaviridae/genética , Infecciones por Papillomavirus/genética , Adulto , Burkina Faso/epidemiología , ADN Viral/análisis , Femenino , Genoma Viral , VIH , Infecciones por VIH/epidemiología , Infecciones por VIH/genética , Seropositividad para VIH/epidemiología , Seropositividad para VIH/genética , Humanos , Papillomaviridae/aislamiento & purificación , Infecciones por Papillomavirus/complicaciones , Infecciones por Papillomavirus/diagnóstico , Infecciones por Papillomavirus/epidemiología , Infecciones por Papillomavirus/terapia , Infecciones por Papillomavirus/virología , Vacunas contra Papillomavirus/administración & dosificación , Vacunas contra Papillomavirus/genética , Vacunas contra Papillomavirus/uso terapéutico , Reacción en Cadena de la Polimerasa , Prevalencia , Neoplasias del Cuello Uterino/epidemiología , Neoplasias del Cuello Uterino/etiología , Neoplasias del Cuello Uterino/genética , Neoplasias del Cuello Uterino/prevención & controlRESUMEN
OBJECTIVES: This work was carried out in order to determine the prevalence of different HPV genotypes in a population of women attending gynecological consultation. MATERIAL AND METHODS: From May to June 2010, cervical samples were obtained from 300 women attending gynecological consultation in two health centers in Ouagadougou. The strains of HPV genotyping was done using the technique of polymerase chain reaction (PCR) followed by reverse hybridization on nitrocellulose strips. RESULTS: Among the 73 women(24.3%) infected with HPV, only 27.4% (20/73) of them were infected with a HPV low risk (BR), the 72.6% (53/73). Other women were infected with at least one high risk HPV (HR). By combining the HPV genotypes found without taking into account the number of infected women, we found a total of 84 HPV among whom we have high-risk HPV : HPV-50'S(26/84 or 31.0%), HPV-18 (12/84 or 14.3%), HPV-16 (9/84 or 10.7%), HPV-30'S (5/84 or 5.9%), HPV-HR (5/84 or 5.9%) and HPV-45 (3/84 or 3.6%) and low-risk HPV: HPV-6 (15/84 or 17.9%) and HPV-BR (9/84 or 10.7%). We have found no HPV-11. DISCUSSION AND CONCLUSION: The prevalence of HPV found in our series is comparable to that found in the world. To complete this study, it would be necessary to investigate the prevalence of HPV found in cervical lesions in Burkina Faso.
Asunto(s)
Papillomaviridae/genética , Infecciones por Papillomavirus/epidemiología , Infecciones por Papillomavirus/virología , Adolescente , Adulto , Burkina Faso/epidemiología , Cuello del Útero/virología , Femenino , Humanos , Incidencia , Persona de Mediana Edad , Prevalencia , Adulto JovenRESUMEN
The vaginal swabs among HIV-positive women in Africa often revealed opportunistic infections such as human Papillomavirus (HPV) and Mycoplasma that induce respectively cervix cancer and diseases such as vaginosis, abortions, infertility in through salpingitis. The purposes of this study were to: (1) seek for, the prevalence of pathogens such as HPV and Mycoplasma; (2) characterize the strains of HPV and estimate their prevalence; (3) identify among these women, those who were co-infected by these pathogens in order to cure them. From February 2009 to January 2010, 156 HIV-positive women attending our medical centers and aged from 19-45 years (mean age 33.65 +/- 5.75 years) had voluntarily accepted vaginal specimen's tests. PCR, ELISA and molecular hybridization were used for the identification and characterization of these pathogens. The results revealed the presence of Mycoplasma and HPV in 25.64 and 58.33% cases, respectively. The following HPV genotypes and the following prevalence were recorded: HPV-50'S (24.11%), HPV-18 (21.28%), HPV-30'S (18.44%) and HPV-16 (5.67%). The study also enable the identification of co-infections such as HPV-18 strains with HPV-30'S (5.67%) and HPV-30'S with HPV-50'S (3.55%). Other germs infecting the female genital tract including Candida albicans (20.51%), Escherichia coli (12.18%), Treponema pallidum (3.85%), Streptococcus agalactiae (3.21%) and Staphylococcus aureus (1.92%) were isolated. This preliminary research work showed the incidence of several genital pathogens, this could be a springboard for nationwide epidemiological study on HPV strains circulating in Burkina Faso.
Asunto(s)
Alphapapillomavirus/aislamiento & purificación , Infecciones por VIH/complicaciones , Infecciones por Papillomavirus/epidemiología , Burkina Faso/epidemiología , Femenino , Humanos , Infecciones por Papillomavirus/complicaciones , PrevalenciaRESUMEN
In Sub-Saharan Africa, many HIV infected people are co-infected with Human Herpes Virus 8 (HHV-8). Therefore, the present study aimed to: (1) identify the pregnant women co-infected by HIV and HHV-8 at Saint Camille Medical Centre; (2) use three molecules (Zidovudine, Nevirapine and Lamivudine) to interrupt the vertical transmission of HIV and (3) use the PCR technique to diagnose children, who were infected by these viruses, in order to offer them an early medical assistance. A total of 107 pregnant women, aged from 19 to 42 years were diagnosed to be HIV positive at Saint Camille Centre; among them 13 were co-infected with HHV-8. All included women received the HAART. Two to six months after childbirth their babies underwent PCR diagnosis for HIV and HHV-8. The results revealed that, among these mothers, 68.2% were housewives, 34.6% were illiterates and 60.7% did not have university degree. The prevalence of HHV-8 among these pregnant women was 12.15% and the rate of vertical transmission of both HIV and HHV-8, was 0.0%. The issue of this study revealed that the antiretroviral therapy increased the mother CD4 T-cells, prevented the transcription of the mRNA of HHV-8 and blocked HIV vertical transmission.
Asunto(s)
Infecciones por VIH/complicaciones , Infecciones por VIH/transmisión , Infecciones por Herpesviridae/complicaciones , Infecciones por Herpesviridae/transmisión , Herpesvirus Humano 8 , Transmisión Vertical de Enfermedad Infecciosa , Complicaciones Infecciosas del Embarazo , Adulto , Fármacos Anti-VIH/uso terapéutico , Burkina Faso , Recuento de Linfocito CD4 , ADN Viral/sangre , ADN Viral/genética , Femenino , Infecciones por VIH/tratamiento farmacológico , VIH-1/genética , Infecciones por Herpesviridae/tratamiento farmacológico , Herpesvirus Humano 8/genética , Humanos , Recién Nacido , Transmisión Vertical de Enfermedad Infecciosa/prevención & control , Lamivudine/uso terapéutico , Nevirapina/uso terapéutico , Reacción en Cadena de la Polimerasa , Embarazo , Complicaciones Infecciosas del Embarazo/tratamiento farmacológico , Adulto Joven , Zidovudina/uso terapéuticoRESUMEN
Toxoplasma gondii infections can induce serious complications in HIV-infected pregnant women, leading to miscarriage; favour the mother-to-child transmission of HBV and HIV and birth defects. The purposes of this study were: (1) to quantify IgM and IgG antibodies to Toxoplasma gondii in HIV-seropositive and seronegative pregnant women, (2) to identify hepatitis B antigens (HBsAg) in pregnant women and (3) to determine T. gondii and HBV co-infections among these patients. The study was conducted at Centre Medical Saint Camille, in Burkina Faso from January to June 2009. A total of 276 HIV-infected and uninfected pregnant women were included. All women had less than 32 weeks of amenorrhoea and were aged from 19 to 42 years. Toxoplasma gondii antibodies and HBsAg were detected using ELISA method. In addition, women freely agreed to answer a questionnaire. The results of our investigations revealed that, among these pregnant women, 38.8% were illiterates, 50.4% were housewives and only 5.4% were civil servants. Positive T. gondii-specific IgM (4.7%) and IgG (27.2%) were detected. In this study, we found that HIV-seropositive status seem to be associated with great prevalence rates of both T. gondii (31.9 vs. 22.5%) and HBV (13.0 vs. 5.8%). The elevated co-infection rate in HIV-positive women suggested that they are exposed to T. gondii and HBV infections prevalently because of their immune depression. Therefore, to reduce the prevalence of T. gondii and HBV among HIV-seropositive pregnant women, lamivudine could be included in their HEART and women should follow healthy lifestyle formation.
Asunto(s)
Infecciones por VIH/epidemiología , Infecciones por VIH/parasitología , Infecciones por VIH/virología , Hepatitis B , Complicaciones Infecciosas del Embarazo , Complicaciones Parasitarias del Embarazo , Toxoplasmosis , Adulto , Fármacos Anti-VIH/uso terapéutico , Burkina Faso/epidemiología , Femenino , Infecciones por VIH/tratamiento farmacológico , Hepatitis B/epidemiología , Hepatitis B/inmunología , Antígenos de la Hepatitis B/sangre , Virus de la Hepatitis B/inmunología , Humanos , Lamivudine/uso terapéutico , Embarazo , Encuestas y Cuestionarios , Toxoplasma/inmunología , Toxoplasmosis/epidemiología , Toxoplasmosis/inmunología , Adulto JovenRESUMEN
We investigated the role of DC-SIGN (CD209), long pentraxin 3 (PTX3) and vitamin D receptor (VDR) gene single nucleotide polymorphisms (SNPs) in susceptibility to pulmonary tuberculosis (TB) in 321 TB cases and 347 healthy controls from Guinea-Bissau. Five additional, functionally relevant SNPs within toll-like receptors (TLRs) 2, 4 and 9 were typed but found, when polymorphic, not to affect host vulnerability to pulmonary TB. We did not replicate an association between SNPs in the DC-SIGN promoter and TB. However, we found that two polymorphisms, one in DC-SIGN and one in VDR, were associated in a nonadditive model with disease risk when analyzed in combination with ethnicity (P=0.03 for DC-SIGN and P=0.003 for VDR). In addition, PTX3 haplotype frequencies significantly differed in cases compared to controls and a protective effect was found in association with a specific haplotype (OR 0.78, 95% CI 0.63-0.98). Our findings support previous data showing that VDR SNPs modulate the risk for TB in West Africans and suggest that variation within DC-SIGN and PTX3 also affect the disease outcome.
Asunto(s)
Proteína C-Reactiva/genética , Moléculas de Adhesión Celular/genética , Lectinas Tipo C/genética , Polimorfismo de Nucleótido Simple , Receptores de Calcitriol/genética , Receptores de Superficie Celular/genética , Componente Amiloide P Sérico/genética , Adolescente , Adulto , Proteína C-Reactiva/metabolismo , Estudios de Casos y Controles , Moléculas de Adhesión Celular/metabolismo , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Guinea Bissau , Haplotipos , Humanos , Lectinas Tipo C/metabolismo , Masculino , Mycobacterium tuberculosis , Receptores de Calcitriol/metabolismo , Receptores de Superficie Celular/metabolismo , Componente Amiloide P Sérico/metabolismo , Receptores Toll-Like/genética , Receptores Toll-Like/metabolismo , Tuberculosis Pulmonar/genética , Tuberculosis Pulmonar/metabolismoRESUMEN
OBJECTIVE: The erythrocyte binding antigen 175 kDa (EBA-175) of Plasmodium falciparum is one of the major ligands for red blood cell invasion by merozoites. EBA-175 is a dimorphic antigen but the role that dimorphism plays in host parasite interaction is not fully understood. In this study, we sought to determine the distribution of EBA-175 genotypes and its pathogenetic influence. METHODS: The nested polymerase chain reaction was used to determine the genotypes of P. falciparum isolates from asymptomatic and symptomatic Gabonese children. RESULTS: CAMP strains (C-segment) and FCR-3 strains (F-segment) were found in 13/50 (26%) and 19/50 (38%) symptomatic children, respectively and in 16/66 (24%) and 46/66 (70%) asymptomatic children, respectively. The prevalence of mixed C-/F- infection was 18/50 (36%) and 4/66 (6%) in symptomatic and asymptomatic children, respectively. CONCLUSIONS: These results show that mixed C-/F- infection is associated with clinical malaria (chi2, P <0.01) and may have important therapeutic implications.
Asunto(s)
Antígenos de Protozoos/genética , Malaria Falciparum/genética , Malaria Falciparum/fisiopatología , Plasmodium falciparum/genética , Proteínas Protozoarias/genética , Adolescente , Animales , Antígenos de Protozoos/fisiología , Niño , Femenino , Gabón/epidemiología , Genes Protozoarios/genética , Genotipo , Humanos , Malaria Falciparum/sangre , Malaria Falciparum/epidemiología , Masculino , Plasmodium falciparum/parasitología , Reacción en Cadena de la Polimerasa , Polimorfismo Genético , Proteínas Protozoarias/fisiología , Distribuciones EstadísticasRESUMEN
Several human genetic factors, including red blood cell polymorphisms (ABO blood group, sickle-cell trait, G6PD deficiency) as well as point mutations in the mannose binding protein (MBP) and in the promoter regions of both the TNF-alpha and NOS2 genes, influence the severity of disease due to infection with Plasmodium falciparum. We assessed their impact on mild P. falciparum malaria, as part of a longitudinal investigation of clinical, parasitological and immunological parameters in a cohort of 300 Gabonese schoolchildren. We found the following frequencies: blood group O (0.54), sickle-cell trait (0.23), G6PD deficiency (0.09), MBP gene mutations (0.34), TNF-alpha promoter mutations (at positions -238: 0.17 and -308: 0.22) and NOS2 promoter mutation (0.18). Blood group O or hemoglobin AA were associated with protection against higher parasitemia. Girls with normal G6PD enzyme activity were protected against clinical malaria attacks. In addition, we demonstrated for the first time that the mutation at position -238 of the gene coding for the promoter region of TNF-alpha was positively correlated with the level of the antibody response specific for epitopes of the antigens MSA-2 and RAP-1 of P. falciparum.