Clinical features of severe malaria: Protective effect of mixed plasmodial malaria

Objective To investigate clinically severe malaria patients with Plasmodium falciparum (P. falciparum), Plasmodium vivax (P. vivax) and mixed species infections. Methods This study was conducted at Dr. Saiful Anwar General Hospital, Malang, Indonesia, from December 2011 to May 2013. Twenty nine patients (mean age of 41 years, 22% female), who suffered from severe malaria according to World Health Organization criteria (major and minor) and other criteria based on previous studies, were selected by consecutive sampling. Blood samples were obtained at admission from peripheral blood for microscopic diagnostic, nested PCR and laboratory examination of blood chemistry. Laboratory results were compared between the groups and correlated to each other. Results From 29 samples, eight (28%) were diagnosed as P. falciparum mono-infection, 12 (41%) as P. vivax mono-infection and nine (31%) as mixed infections, confirmed by PCR. Cerebral malaria occurred in P. falciparum or mixed species infection only. Parasitaemia was highest in P. falciparum mono-infection. Mean haemoglobin was significantly lower in P. falciparum than P. vivax infection (P = 0.01). Mean thrombocyte count (77 138/μL) was low in all groups. Mean urea, creatinine, total and direct bilirubin were significantly higher in P. falciparum mono-infection compared to other groups, whereas aspartate aminotransferase and alanine aminotransferase showed no significant differences. Parasitaemia was positively correlated with an increase in urea, creatinine, bilirubin and leucocytosis in all species. Conclusions Both Plasmodium species can solely or in combination cause severe malaria. Mixed infection was generally more benign than P. falciparum mono-infection and seemed to have some protective effects.

Plasma glutathione and oxidized glutathione level, glutathione/oxidized glutathione ratio, and albumin concentration in complicated and uncomplicated falciparum malaria

Objective To compare the level of glutathione (GSH) and oxidized glutathione (GSSG), the ratio of GSH/GSSG and the concentration of albumin in plasma of patients with complicated and un-complicated falciparum malaria. Methods This research was a cross sectional study using comparison analysis with the plasma GSH and GSSG, the ratio of plasma GSH/GSSG and the concentration of plasma albumin as variables. The complicated malaria patients were obtained from Dr. Saiful Anwar Hospital Malang, whereas uncomplicated malaria patients were obtained from the Regency of Pleihari South Kalimantan. Plasma GSH and GSSG levels were determined by the spectrophotometer at the wave length of 412 nm, whereas the concentration of albumin was determined by bromocresol green method in the pH of 4.1. Results There were no significant differences between the level of plasma GSH and GSSG in complicated and uncomplicated malaria patients, as well as the ratio of plasma GSH/GSSG in the two groups (P = 0.373; P = 0.538; and P = 0.615, respectively, independent t-test). In contrast, the plasma albumin concentration in complicated malaria patients were significantly higher than uncomplicated malaria patients (P = 0.000, Mann Whitney U test). Conclusions It can be concluded that the average of plasma GSH and GSSG level, also plasma GSH/GSSG ratio in complicated malaria are not different from uncomplicated malaria. Although plasma concentration of albumin in both groups is below the normal range, there is an increase in complicated malaria that might be as compensation of oxidative stress.

Identification of antigenic proteins from salivary glands of female Anopheles maculatus by proteomic analysis

Objective To identify antigenic proteins from the salivary glands of female Anopheles maculatus using a proteomic approach to find the biomarker candidate for serological tools. Methods The identification of antigenic proteins of Anopheles maculatus salivary gland used these techniques: one-dimensional gel electrophoresis (sodium dodecyl sulfate polyacrylamide gel electrophoresis), western blot, and liquid chromatography–mass spectrometry. Results The proteins that have molecular weight (MW) 43 and 34 kDa were the antigenic protein. Computational bioinformatic analysis by Mascot Server revealed seven novel hypothetical proteins (MW: 43 kDa) and two novel hypothetical proteins (MW: 34 kDa). Further analysis (BLASTP, antigenicity, epitope mapping, and specificity analysis) showed that two novel proteins were identified as apolipoprotein D and cathepsin D in Anopheles darlingi. Conclusions The identified proteins are potential to be developed as a biomarker of mosquito bite's exposure.

Parasitemia Induces High Plasma Levels of Interleukin-17 (IL-17) and Low Levels of Interleukin-10 (IL-10) and Transforming Growth Factor-ß (TGF-ß) in Pregnant Mice Infected with Malaria

Background: During pregnancy, the balanced dominance of the T helper17 response shifts to a Th2 response that is characterised by the production of IL-10, following the completion of the implantation process. Transforming growth factor-β (TGF-β) expression is associated with the completion of trophoblast invasion and placental growth. This study assessed the effect of malaria infection on the levels of IL-17, IL-10, and TGF-β in the plasma of pregnant mice with malaria. Methods: Seventeen pregnant BALB/C mice were divided into two groups: mice infected with Plasmodium berghei (treatment group) and uninfected mice (control group). The mice were sacrificed on day 18 post-mating. Parasitemia was measured by Giemsa staining. The levels of IL-17, IL-10, and TGF-β were measured by ELISA. Results: Using independent t test, the IL-17 levels in the treatment group were higher than those in the control group (P = 0.040). The IL-10 levels in the treatment group were lower than those in the control group (P = 0.00). There was no significant difference in the TGF-β levels (P = 0.055) between two groups. However, using SEM analysis the degree of parasitemia decreased the plasma TGF-β levels (tcount = 5.148; ≥ ttable = 1.96). SEM analysis showed that a high degree of parasitemia increased the IL-17 levels and decreased the IL-10 and TGF-β levels. Conclusion: Malaria infection during pregnancy interferes with the systemic balance by increasing the IL-17 levels and decreasing the IL-10 and TGF-β levels.

Low Fetal Weight is Directly Caused by Sequestration of Parasites and Indirectly by IL-17 and IL-10 Imbalance in the Placenta of Pregnant Mice with Malaria

The sequestration of infected erythrocytes in the placenta can activate the syncytiotrophoblast to release cytokines that affect the micro-environment and influence the delivery of nutrients and oxygen to fetus. The high level of IL-10 has been reported in the intervillous space and could prevent the pathological effects. There is still no data of Th17 involvement in the pathogenesis of placental malaria. This study was conducted to reveal the influence of placental IL-17 and IL-10 levels on fetal weights in malaria placenta. Seventeen pregnant BALB/C mice were divided into control (8 pregnant mice) and treatment group (9 pregnant mice infected by Plasmodium berghei). Placental specimens stained with hematoxylin and eosin were examined to determine the level of cytoadherence by counting the infected erythrocytes in the intervillous space of placenta. Levels of IL-17 and IL-10 in the placenta were measured using ELISA. All fetuses were weighed by analytical balance. Statistical analysis using Structural Equation Modeling showed that cytoadherence caused an increased level of placental IL-17 and a decreased level of placental IL-10. Cytoadherence also caused low fetal weight. The increased level of placental IL-17 caused low fetal weight, and interestingly low fetal weight was caused by a decrease of placental IL-10. It can be concluded that low fetal weight in placental malaria is directly caused by sequestration of the parasites and indirectly by the local imbalance of IL-17 and IL-10 levels.