Biology subjects

Macete, E.

Publications and source records attributed to Macete, E..

3 recordsLinked to original sources

bioRxiv2026

Severe malarial anaemia is associated with parasite enrichment and host alterations in the bone marrow

BackgroundMalaria poses a significant global health challenge, with over 200 million infections and around 500,000 deaths annually, predominantly affecting children under 5 in sub-Saharan Africa. Severe malarial anaemia (SMA), a major contributor to morbidity and mortality in this demographic, results from various factors including red blood cell destruction and immune-mediated clearance. The role of these mechanisms in SMA differs based on age and infection history. Recent studies indicate increased accumulation of P. falciparum in the bone marrow and spleen, highlighting the need for understanding localized host-parasite interactions. MethodsThis study examines the bone marrow response to malarial infection in young children with SMA or mild malarial malaria in Mozambique, contrasting it with responses observed in peripheral blood in the two cohorts. Results and conclusionsThe study demonstrated that SMA is associated with increased red blood cell production, iron metabolism and tissue injury, as well as higher total parasite biomass including peripheral and bone marrow parasitaemia. We also demonstrate that direct analysis of bone marrow aspirates provides far more resolution in stratifying host signatures and drivers of malarial anaemia across a spectrum of severity than systemic measures from blood samples.

microbiology↗

bioRxiv2020

Reduced placental transfer of antibodies against microbial and vaccine antigens in HIV-infected women in Mozambique

Antibody transplacental transfer is essential for conferring protection in newborns against infectious diseases. This transfer may be affected by gestational age and maternal infections, although the effects are not consistent across studies. We measured total IgG and IgG subclasses by quantitative suspension array technology against fourteen pathogens and vaccine antigens, including target of maternal immunization, in 341 delivering HIV- and HIV+ mother-infant pairs from southern Mozambique. Maternal antibody levels were the main determinant of cord antibody levels. HIV broadly reduced the placental transfer and cord levels of IgG and IgG1, but also IgG2 to half of the antigens. Plasmodium falciparum exposure and prematurity were negatively associated with cord antibody levels and placental transfer but this was antigen-subclass dependent. These findings suggest maternal infections may impact the efficacy of maternal immunization and confirm the lower transfer of antibodies as one of the causes underlying increased susceptibility to infections in HIV-exposed infants.

immunology↗

bioRxiv2019

Quantification of malaria antigens PfHRP2 and pLDH by quantitative suspension array technology in whole blood, dried blood spot and plasma

BackgroundMalaria diagnostics by rapid diagnostic tests (RDTs) relies primarily on the qualitative detection of Plasmodium falciparum histidine-rich protein 2 (PfHRP2) and Plasmodium sp lactate dehydrogenase (pLDH). As novel RDTs with increased sensitivity are being developed and implemented as point of care diagnostics, highly sensitive laboratory based assays are needed for evaluating RDTs performance. Here, a quantitative suspension array technology (qSAT) was developed, validated and applied for the simultaneous detection of PfHRP2 and pLDH in a variety of clinical samples (whole blood, plasma and dried blood spots) from different endemic countries.\n\nResultsThe qSAT was specific for the target antigens, with analytical ranges of 6.8 to 762.8 pg/ml for PfHRP2 and 78.1 to 17076.6 pg/ml for P. falciparum (Pf-LDH). The assay detected P. vivax LDH (Pv-LDH) at a lower sensitivity than Pf-LDH (analytical range of 1093.20 to 187288.5 pg/ml). Both PfHRP2 and pLDH levels determined using the qSAT showed to positively correlate with parasite densities determined by quantitative PCR (Spearman r=0.59 and 0.75, respectively) as well as microscopy (Spearman r=0.40 and 0.75, respectively), suggesting the assay to be a good predictor of parasite density.\n\nConclusionThis immunoassay can be used as a reference test for the detection and quantification of PfHRP2 and pLDH, and could serve for external validation of RDTs performance, to determine antigen persistence after parasite clearance, as well as a complementary tool to assess malaria burden in endemic settings.

microbiology↗