Tumor necrosis factor in falciparum malaria

Tumour necrosis factor-α as a prognostic biomarker of severe malaria: a systematic review and meta-analysis

BACKGROUND

Tumour necrosis factor-alpha (TNF-α) levels are reportedly altered during malaria. In this systematic review and meta-analysis, we aimed to collect and compare data on TNF-α levels between patients with malaria of varying severity and healthy asymptomatic positive controls.

METHODS

We searched PubMed, Scopus and Web of Science for studies that reported TNF-α levels in malaria cases of different severity and healthy asymptomatic positive controls using a combination of search terms. The quality of the included studies was assessed using the Strengthening the Reporting of Observational Studies in Epidemiology checklist. To compare the TNF-α levels among fatal cases, severe cases, uncomplicated cases and healthy asymptomatic positive controls, we applied the random-effects model that assumed the existence of variations between studies. The effect estimate was pooled mean difference (MD) with a 95% confidence interval (CI).

RESULTS

From 1694 studies, we included 31 studies that met our eligibility criteria for systematic review and meta-analysis. Patients with severe malaria showed higher mean TNF-α levels than those with uncomplicated malaria (P < 0.001, pooled MD = 79.02 pg/ml, 95% CI: 63.68-94.35 pg/ml, I2: 99.5%, n = 26 studies). Furthermore, fatal cases had no difference in the mean TNF-α levels in comparison with survived cases (P = 0.055, pooled MD = 82.38 pg/ml, 95% CI: -1.93 to 166.69 pg/ml, I2: 99.54%, n = 5 studies). Finally, patients with uncomplicated malaria showed higher mean TNF-α levels than those with asymptomatic malaria (P < 0.001, pooled MD = 45.10 pg/ml, 95% CI: 18.45-71.76 pg/ml, I2: 97.09%, n = 5 studies).

CONCLUSION

This systematic review and meta-analysis confirmed the increase of TNF-α levels in patients with severe malaria. Therefore, TNF-α may be alternatively used as a prognostic biomarker of severe malaria.

TRIAL REGISTRATION

Not applicable.

Association between inflammatory cytokine levels and anemia during Plasmodium falciparum and Plasmodium vivax infections in Mangaluru: A Southwestern Coastal Region of India

Background and Objectives:

Dysregulated production of inflammatory cytokines might play important role in anemia during malaria infection. The objective of this study was to assess the extent of anemia due to malaria, associated complications, and inflammatory cytokines (tumor necrosis factor alpha [TNF-α], interleukin [IL]-6, and IL-10) across varying anemic intensity during malaria infections.

Materials and Methods:

A hospital-based cross-sectional study was conducted at District Wenlock hospital in Mangaluru city. Samples from 627 patients and 168 healthy controls (HC) were analyzed for level of hemoglobin (Hb), red blood cells (RBCs), and inflammatory cytokines. The blood cell parameters and inflammatory cytokines levels across varying intensity of anemia were analyzed using Kruskal–Wallis test and pair-wise comparison between two groups were by Mann–Whitney U-test. Correlations were calculated by Pearson's and Spearman rank correlations.

Results:

Compared to HC, Hb, and RBC levels were significantly lower in infected patients. On comparison with mild anemia patients (Hb 8–10.9 g/dL), the levels of TNF-α and IL-6 were significantly elevated, whereas IL-10 levels were lower during severe anemia (SA) (Hb <5 g/dL). In this endemic setting, we found a strong negative association between Hb levels and parasitemia, Hb and TNF-α, and positive relationship with IL-10; anemic patients also had significantly high TNF-α/IL-10 ratios. SA was associated with complications such as acute renal failure (16.0%), jaundice (16.0%), metabolic acidosis (24.0%), hypoglycemia (12.0%), hyperparasitemia (4.0%), and hepatic dysfunction (16.0%).

Conclusions:

Contrary to its benign reputation, Plasmodium vivax (Pv) infections can also result in severe malarial anemia (SMA) and its associated severe complications similar to Plasmodium falciparum infections. Dysregulated inflammatory cytokine responses play an important role in the pathogenesis of SMA, especially during Pv infections.

Hypoglycemia induced by Plasmodium berghei infection is prevented by treatment with Tinospora crispa stem extract

During Plasmodium malaria parasite infection in a human, the intraerythrocytic stages lead to the clinical manifestations of the disease, especially hypoglycemia. Hypoglycemia is a recognized feature of severe malaria and linked with a high risk of mortality for children. Hence, the present study aimed to investigate the protective effect of T. crispa stem extract on hypoglycemia induced by P. berghei infection tested with a mouse model. ICR mice were inoculated with 1 × 10⁷ parasitized erythrocytes of P. berghei ANKA (PbANKA) by intraperitoneal injection and given 50, 100, and 200 mg/kg of ethanolic extract for 4-consecutive days. The results showed that T. crispa stem extract exerted a protective effect (100%) on hypoglycemia induced by PbANKA infection at doses of 100 and 200 mg/kg. A significantly (p < .05) prolonged mean survival time (28.0 ± 1.9 days) of the extract treated mice was also observed. Additionally, no effect on blood glucose levels was seen in normal mice treated with all doses of extract. It can be concluded that T. crispa stem extract may have beneficial properties in protecting against hypoglycemia, and in increasing survival time during malaria infection.