Serum ferritin levels in children with malaria anaemia in Ibadan

This study assessed the serum ferritin levels in plasma samples from children (4 – 74 months old) admitted for malaria at the Adeoyo Maternity Hospital (Beere) Ibadan, Oyo State, using a sandwich-ELISA. These values were compared with malaria parasitemia, MSP-1 antibody titre and packed cell volume values previously obtained through standard methods. Statistical analyses were carried out using SPSS, Excel and Epi-Calc software. Results showed that theserum ferritin level in the population ranged in from 363ng/ml to 1000ng/ml, with a mean value of 630ng/ml. There was a negative correlation between serum ferritin levels and the packed cellvolume, and malaria parasitemia in the children; while the serum ferritin levels increased with increasing malaria antibodies. There was no significant difference in the mean levels of ferritin in anaemic and non-anaemic children. Serum ferritin concentration decreased with increasing age in children with malaria. Gender was found to have no significant association with serum ferritin levels in children with malaria anaemia

Differential antibody responses to Plasmodium falciparum merozoite proteins in Malawian children with severe malaria

Cerebral malaria (CM) and severe malarial anemia (SMA) are 2 major causes of death in African children infected with Plasmodium falciparum. We investigated levels of naturally acquired antibody to conserved and variable regions of merozoite surface protein (MSP)-1 and MSP-2, apical membrane antigen (AMA)-1, and rhoptry-associated protein 1 in plasma samples from 126 children admitted to the hospital with CM, 59 with SMA, and 84 with uncomplicated malaria (UM) in Malawi. Children with SMA were distinguished by very low levels of immunoglobulin (Ig) G to the conserved C-terminus of MSP-1 and MSP-2 and to full-length AMA-1. Conversely, children with CM had significantly higher levels of IgG to the conserved regions of all antigens examined than did children with UM (for MSP-1 and AMA-1, P< .005; for MSP-2, P< .05) or SMA (for MSP-1 and MSP-2, P<.001; for AMA-1, P< .005). These distinct IgG patterns might reflect differences in age, exposure to P. falciparum, and/or genetic factors affecting immune responses

Genetic characterization of fin fish species from the Warri River at Ubeji, Niger Delta, Nigeria

A study to evaluate the genetic similarities and differences among 11 specimens of cichlids and four specimens of mudcatfishes obtained from Warri River was carried out through DNA fingerprinting analysis using random amplified polymorphic DNA (RAPD)-PCR amplification with seven decamer primers and dendrograms through unweighted pair-group method with average (UPGMA) cluster analysis. The total number of bands generated by the seven RAPD primers, ranged between 2 to 33 for the cichlids and 8 to 28 for the catfish family, with band size between 100 to 800 bp. The primers produced 228 bands in total 119 for the cichlids and 109 for the catfishes, with 24% polymorphism. Considerable genetic variation was observed within species (especially within Tilapia zilli, T. guineensis and Clarias gariepinus), between species in the same genera (T. zilli and T. guineensis) and among cichlids and catfishes. The most consistent of the RAPD primers generated 87 bands among the cichlids with 23 bands (26%) polymorphic and 74% conserved. Among the catfishes, the primers produced 69 bands with 16 (23%) polymorphic. The data show that the RAPD technique was useful and sensitive in differentiating various fish genera and species.Keywords: Random amplified polymorphic DNA (RAPD), Niger Delta, aquatic diversity, phylogenyAfrican Journal of Biotechnology, Vol 13(26) 2689-269

Optimization of the T-cell proliferation assay in fascioliasis using a non-radioactive method, the Alamar Blue Assay

T-cell proliferation studies are traditionally carried out with radioactive reagents or fluorescent reagents that require measurement with advanced technology instrumentation. We attempted to calibrate the optimal conditions suitable for the use of a non-radioactive assay for the measurement of a T-cell proliferation assay in bovine fascioliasis, but applicable to the study ofother infectious diseases in our developing country setting. Crude antigen extract was prepared from 15 adult Fasciola gigantica flukes. Cellular responses were detected by the proliferation of peripheral blood mononuclear cells (PBMC) in response to stimulation by serial dilutions of the crude antigen extract. The results showed that the antigen dilution 1:1,600 gave the highest PBMC proliferative response (Stimulation Index, S.I = 1.10± 0.2). Percentage reduced Alamar Blue was 27.3- 71.6%. This suggests that the cell-mediated immune response in bovine immunity to Fasciola infection may be reliablymeasured in our setting with the Alamar Blue Assay

Schistosome Specific Antibodies in Individuals Co-Infected with Malaria in Southwest Nigeria

A cross-sectional study design in two primary schools in Ibadan and Akure was used to determine the prevalence of urinary schistosomiasis, and the human humoral immune response to schistosome antigens in individuals with malaria co-infection. Urine samples were collected from 163 children, while 112 gave blood samples. Malaria parasitaemia was determined by microscopy after Giemsa staining and schistosomiasis by centrifugation technique. Serum samples were analyzed for antibodies to crude S. mansoni soluble egg, adult worm antigens, and crude S. haematobium egg antigen by ELISA. The sample population consisted of 40% (62/163) infected with schistosomiasis, 31% (50/163) with malaria, and 6% (10/163) co-infected. All the co-infected students had asymptomatic malaria with parasite densities ranging from 200 - 4,420 parasites/ul blood. IgG titres to the various Schistosoma antigens did not vary significantly. However, antibody titres to the soluble egg antigen increased with age of volunteers. Antigen specific isotype distribution showed a higher prevalence of IgG3 and IgG4.Keywords: Schistosomiasis, antibodies, co-infection, malaria, ELISANigerian Journal of Parasitology, Vol. 33 [2] September 2012, pp. 133-13

Cytokine profiles and antibody responses to Plasmodium falciparum malaria infection in individuals living in Ibadan, southwest Nigeria

Background: The ability of the host immune system to efficiently clear Plasmodium falciparum parasites during a malaria infection depends on the type of immune response mounted by the host.Study design: In a cross-sectional study, we investigated the cellular-and antibody responses in individuals with P. falciparum infection, in an attempt to identify immunological signs indicative of the development of natural immunity against malaria in Ibadan, Nigeria. Levels of IL-10, IL-12(p70), IFN-γ, and IgM, IgG and IgG1-4 subclasses in the serum of 36 symptomatic children with microscopically confirmed malaria parasitaemia and 54 asymptomatic controls were analysed by ELISA.Results: IFN-γ and IL-10 were significantly higher in the symptomatic children (p=0.009, p=0.025 respectively) than in the asymptomatic controls but no differences were seen for IL-12(p70). Estimated higher ratios of IFN-γ/IL-10 and IFN-γ/IL-12 were also observed in the symptomatic children while the asymptomatic controls had higher IL-12/IL-10 ratio. The mean concentration levels of anti-P. falciparum IgG1, IgG2, IgG3 antibodies were statistically significantly higher in the individuals >5 years of age tha

Acquisition, maintenance and adaptation of invasion inhibitory antibodies against Plasmodium falciparum invasion ligands involved in immune evasion

Erythrocyte-binding antigens (EBAs) and P. falciparum reticulocyte-binding homologue proteins (PfRhs) are two important protein families that can vary in expression and utilization by P. falciparum to evade inhibitory antibodies. We evaluated antibodies at repeated time-points among individuals living in an endemic region in Nigeria over almost one year against these vaccine candidates. Antibody levels against EBA140, EBA175, EBA181, PfRh2, PfRh4, and MSP2, were measured by ELISA. We also used parasites with disrupted EBA140, EBA175 and EBA181 genes to show that all these were targets of invasion inhibitory antibodies. However, antigenic targets of inhibitory antibodies were not stable and changed substantially over time in most individuals, independent of age. Antibodies levels measured by ELISA also varied within and between individuals over time and the antibodies against EBA181, PfRh2 and MSP2 declined more rapidly in younger individuals (≤15 years) compared with older (>15). The breadth of high antibody responses over time was more influenced by age than by the frequency of infection. High antibody levels were associated with a more stable invasion inhibitory response, which could indicate that during the long process of formation of immunity, many changes not only in levels but also in functional responses are needed. This is an important finding in understanding natural immunity against malaria, which is essential for making an efficacious vaccine