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BACKGROUND: Efforts on a global scale for combating malaria have achieved substantial progress over the past twenty years. Two Central American nations have accomplished their goal of eliminating malaria: El Salvador and Belize. Honduras has decreased the incidence of malaria and now reports fewer than 4000 malaria cases annually, aspiring to reach elimination by 2030. To accomplish this goal, it is essential to assess the existing strategies employed for malaria control and to address the task of incorporating novel intervention strategies to identify asymptomatic reservoirs. METHODS: A survey for detecting asymptomatic cases was carried out in the community of Kaukira, in Gracias a Dios, Honduras, focusing on malaria transmission during 2023. Asymptomatic community members were recruited as participants, malaria screening was performed through a rapid diagnostic test in situ, and a blood sample was collected on filter paper. Highly sensitive molecular assays based on photo-induced electron transfer PCR (PET-PCR) were performed to detect the two species of Plasmodium circulating in Honduras: Plasmodium vivax and Plasmodium falciparum. In addition, the identification of the parasite species was verified by amplifying three genetic markers (Pvmsp3α, Pvmsp3ß, and Pfmsp1). RESULTS: A total of 138 participants were recruited, mostly adult women. All individuals tested negative on the rapid diagnostic test. Positive results for malaria were detected by PET-PCR in 17 samples (12.3%). Most samples (12 out of 17) were amplified with a Ct value between 37 and 42, indicating very low parasitemias. Out of the 17 samples, 16 of them also showed amplification in the species assays. There were nine cases of P. falciparum infections and seven cases of P. vivax infections that were further confirmed by nested PCR (nPCR) of Pvmsp3 and Pfmsp1. Parasitemias ranged from 100 p/µL to less than 0.25 p/µL. One sample showed mixed infection. CONCLUSIONS: The existence of asymptomatic malaria reservoirs in Honduras can contribute to disease transmission and pose a challenge that may hinder elimination efforts, requiring public health authorities to modify surveillance strategies to identify the disease and treat this population accordingly.
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BACKGROUND: Malaria remains a main parasitic disease of humans. Although the largest number of cases is reported in the African region, there are still endemic foci in the Americas. Central America reported 36,000 malaria cases in 2020, which represents 5.5% of cases in the Americas and 0.015% of cases globally. Most malaria infections in Central America are reported in La Moskitia, shared by Honduras and Nicaragua. In the Honduran Moskitia, less than 800 cases were registered in 2020, considering it an area of low endemicity. In low endemicity settings, the number of submicroscopic and asymptomatic infections tends to increase, leaving many cases undetected and untreated. These reservoirs challenge national malaria elimination programmes. This study aimed to assess the diagnostic performance of Light Microscopy (LM), a nested PCR test and a photoinduced electron transfer polymerase chain reaction (PET-PCR) in a population of febrile patients from La Moskitia. METHODS: A total of 309 febrile participants were recruited using a passive surveillance approach at the Puerto Lempira hospital. Blood samples were analysed by LM, nested PCR, and PET-PCR. Diagnostic performance including sensitivity, specificity, negative and positive predictive values, kappa index, accuracy, and ROC analysis was evaluated. The parasitaemia of the positive samples was quantified by both LM and PET-PCR. RESULTS: The overall prevalence of malaria was 19.1% by LM, 27.8% by nPCR, and 31.1% by PET-PCR. The sensitivity of LM was 67.4% compared to nPCR, and the sensitivity of LM and nPCR was 59.6% and 80.8%, respectively, compared to PET-PCR. LM showed a kappa index of 0.67, with a moderate level of agreement. Forty positive cases by PET-PCR were not detected by LM. CONCLUSIONS: This study demonstrated that LM is unable to detect parasitaemia at low levels and that there is a high degree of submicroscopic infections in the Honduran Moskitia.
Assuntos
Malária Falciparum , Malária , Humanos , Malária/epidemiologia , Malária/diagnóstico , Reação em Cadeia da Polimerase , Técnicas de Amplificação de Ácido Nucleico , Parasitemia/epidemiologia , Tomografia por Emissão de Pósitrons , Malária Falciparum/parasitologia , Sensibilidade e Especificidade , Plasmodium falciparum/genéticaRESUMO
INTRODUCTION: Common variable immunodeficiency is a heterogeneous syndrome characterized by recurrent infections, hypogammaglobulinemia and defective production of specific antibodies. Abnormalities in peripheral blood lymphocyte subpopulations, in particular of B lymphocytes, allow the classification of patients into homogeneous groups. OBJECTIVE: To perform a clinical and immunological characterization and to evaluate lymphocyte subpopulations of twelve Colombian patients with common variable immunodeficiency in order to define homogeneous groups. MATERIALS AND METHODS: We reviewed medical records and evaluated serum immunoglobulins (Ig), lymphoproliferation, delayed hypersensitivity and used flow cytometry to quantify peripheral blood total lymphocyte and B cell populations. RESULTS: All patients had recurrent respiratory and/or gastrointestinal infections, while some also had infections affecting other systems. All patients had abnormally low serum IgG levels, while IgA and IgM levels were reduced in nine and ten patients, respectively. Lymphoproliferation to mitogen was lower in patients than in healthy controls but lymphoproliferation to specific antigen was normal in all. Flow cytometry revealed high numbers of T cells in three patients, while seven had a low CD4+/CD8+ ratio and four had reduced NK cells . Eleven patients had normal B cell counts, and eight of them also showed decreased memory B lymphocytes, and four had increased transitional or CD21 low B lymphocytes. CONCLUSION: Lymphocyte typing allowed assigning all but one patient to homogeneous groups according to international classification schemes, indicating the necessity of including more criteria until an ideal classification is achieved. This study will lead to a better medical monitoring of common variable immunodeficiency patients in groups at high risk of developing clinical complications.
Assuntos
Subpopulações de Linfócitos B , Imunodeficiência de Variável Comum/diagnóstico , Imunodeficiência de Variável Comum/imunologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Imunodeficiência de Variável Comum/sangue , Feminino , Humanos , Imunofenotipagem , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
BACKGROUND: SLC10A4 belongs to the solute carrier family SLC10 whose founding members are the Na(+)/taurocholate co-transporting polypeptide (NTCP, SLC10A1) and the apical sodium-dependent bile acid transporter (ASBT, SLC10A2). These carriers maintain the enterohepatic circulation of bile acids between the liver and the gut. SLC10A4 was identified as a novel member of the SLC10 carrier family with the highest phylogenetic relationship to NTCP. The SLC10A4 protein was detected in synaptic vesicles of cholinergic and monoaminergic neurons of the peripheral and central nervous system, suggesting a transport function for any kind of neurotransmitter. Therefore, in the present study, we performed systematic transport screenings for SLC10A4 and also aimed to identify the vesicular sorting domain of the SLC10A4 protein. RESULTS: We detected a vesicle-like expression pattern of the SLC10A4 protein in the neuronal cell lines SH-SY5Y and CAD. Differentiation of these cells to the neuronal phenotype altered neither SLC10A4 gene expression nor its vesicular expression pattern. Functional transport studies with different neurotransmitters, bile acids and steroid sulfates were performed in SLC10A4-transfected HEK293 cells, SLC10A4-transfected CAD cells and in Xenopus laevis oocytes. For these studies, transport by the dopamine transporter DAT, the serotonin transporter SERT, the choline transporter CHT1, the vesicular monoamine transporter VMAT2, the organic cation transporter Oct1, and NTCP were used as positive control. SLC10A4 failed to show transport activity for dopamine, serotonin, norepinephrine, histamine, acetylcholine, choline, acetate, aspartate, glutamate, gamma-aminobutyric acid, pregnenolone sulfate, dehydroepiandrosterone sulfate, estrone-3-sulfate, and adenosine triphosphate, at least in the transport assays used. When the C-terminus of SLC10A4 was replaced by the homologous sequence of NTCP, the SLC10A4-NTCP chimeric protein revealed clear plasma membrane expression in CAD and HEK293 cells. But this chimera also did not show any transport activity, even when the N-terminal domain of SLC10A4 was deleted by mutagenesis. CONCLUSIONS: Although different kinds of assays were used to screen for transport function, SLC10A4 failed to show transport activity for a series of neurotransmitters and neuromodulators, indicating that SLC10A4 does not seem to represent a typical neurotransmitter transporter such as DAT, SERT, CHT1 or VMAT2.
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Transporte Biológico/fisiologia , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Animais , Proteínas de Transporte de Ânions , Western Blotting , Linhagem Celular Tumoral , Imunofluorescência , Células HEK293 , Humanos , Proteínas de Membrana/genética , Camundongos , Proteínas do Tecido Nervoso/genética , Neurônios/metabolismo , Oócitos , Reação em Cadeia da Polimerase em Tempo Real , Simportadores , Transfecção , Proteínas de Transporte Vesicular/genética , Xenopus laevisRESUMO
Introducción. La inmunodeficiencia común variable es un síndrome heterogéneo caracterizado por infecciones recurrentes, hipogammaglobulinemia y producción deficiente de anticuerpos específicos. Las anormalidades en subpoblaciones de linfocitos en sangre periférica, particularmente de linfocitos B, permiten la clasificación de los pacientes en grupos homogéneos. Objetivo. Caracterizar clínica e inmunológicamente los linfocitos B y tipificar sus subpoblaciones en doce pacientes colombianos con inmunodeficiencia común variable, para clasificarlos en grupos homogéneos. Materiales y métodos. Se revisaron las historias clínicas de los pacientes y se evaluaron las inmunoglobulinas séricas, la proliferación de linfocitos y la hipersensibilidad retardada, así como las subpoblaciones de linfocitos y de linfocitos B mediante citometría de flujo. Resultados. Todos los pacientes presentaron infecciones respiratorias o gastrointestinales recurrentes y, algunos, infecciones en otros sistemas. Además, todos presentaban disminución de la IgG, en tanto que la IgA y la IgM fueron bajas en nueve y diez pacientes, respectivamente. En todos hubo disminución de la proliferación de linfocitos inducida por mitógenos, pero fue normal frente a antígenos específicos. La tipificación de subpoblaciones reveló valores elevados de linfocitos T en tres pacientes; siete presentaron disminución en la relación CD4+/CD8+ y, cuatro, linfocitos NK bajos. El conteo de linfocitos B fue normal en once pacientes, ocho de los cuales presentaron linfocitos B de memoria bajos, en tanto que cuatro presentaron aumento de linfocitos B de transición o de linfocitos B CD21 low . Conclusión. La tipificación de subpoblaciones de linfocitos solo permitió asignar a 11 de los pacientes a grupos homogéneos según los esquemas de clasificación internacionales, lo que indica la necesidad de agregar más criterios hasta lograr una clasificación ideal. Este estudio permitirá establecer mejores seguimientos médicos para pacientes con inmunodeficiencia común variable en grupos con alto riesgo de desarrollar complicaciones clínicas.
Introduction: Common variable immunodeficiency is a heterogeneous syndrome characterized by recurrent infections, hypogammaglobulinemia and defective production of specific antibodies. Abnormalities in peripheral blood lymphocyte subpopulations, in particular of B lymphocytes, allow the classification of patients into homogeneous groups. Objective: To perform a clinical and immunological characterization and to evaluate lymphocyte subpopulations of twelve Colombian patients with common variable immunodeficiency in order to define homogeneous groups. Materials and methods: We reviewed medical records and evaluated serum immunoglobulins (Ig), lymphoproliferation, delayed hypersensitivity and used flow cytometry to quantify peripheral blood total lymphocyte and B cell populations. Results: All patients had recurrent respiratory and/or gastrointestinal infections, while some also had infections affecting other systems. All patients had abnormally low serum IgG levels, while IgA and IgM levels were reduced in nine and ten patients, respectively. Lymphoproliferation to mitogen was lower in patients than in healthy controls but lymphoproliferation to specific antigen was normal in all. Flow cytometry revealed high numbers of T cells in three patients, while seven had a low CD4+/CD8+ ratio and four had reduced NK cells . Eleven patients had normal B cell counts, and eight of them also showed decreased memory B lymphocytes, and four had increased transitional or CD21 low B lymphocytes. Conclusion: Lymphocyte typing allowed assigning all but one patient to homogeneous groups according to international classification schemes, indicating the necessity of including more criteria until an ideal classification is achieved. This study will lead to a better medical monitoring of common variable immunodeficiency patients in groups at high risk of developing clinical complications.