Transforming Growth Factor-β Concerning Malarial Infection and Severity: A Systematic Review and Meta-Analysis

Transforming growth factor-beta (TGF-beta) is important in the pathophysiology of malaria, but its role in acute and severe malaria is largely unknown. As a result, this study used a meta-analysis approach to investigate the difference in TGF-beta levels between several groups of malaria patients and healthy controls. The systematic review protocol was registered at PROSPERO (ID: CRD42022318864). From inception to 7 March 2022, studies that reported TGF-beta levels in patients with uncomplicated and healthy controls and patients with severe and uncomplicated malaria were searched in PubMed, Scopus and Embase. The assessment of the quality of the included studies was conducted according to the Strengthening the Reporting of Observational Studies in Epidemiology guidelines. Qualitative and quantitative syntheses were performed to narratively describe and quantitatively pool the mean difference (MD) in TGF-beta levels between uncomplicated malaria and healthy controls, and between severe and uncomplicated malaria, using a random-effects model. A total of 1027 relevant articles were identified, and 13 studies were included for syntheses. The meta-analysis results show 233 patients with uncomplicated malaria and 239 healthy controls. Patients with uncomplicated malaria (233 cases) had lower mean TGF-beta levels than healthy controls (239 cases; p < 0.01, pooled MD = -14.72 pg/mL, 95% confidence interval (95% CI) = -20.46 to 8.99 pg/mL, I-2 = 98.82%, seven studies). The meta-analysis found no difference in mean TGF-beta levels between patients with severe malaria (367 cases) and patients with uncomplicated malaria (180 cases; p = 0.11, pooled MD = -6.07 pg/mL, 95% CI = -13.48 to 1.35 pg/mL, I-2 = 97.73%, six studies). The meta-analysis demonstrated decreased TGF-beta levels in patients with uncomplicated malaria compared to healthy controls. In addition, no difference in TGF-beta levels was found between patients with severe and uncomplicated malaria. More research is needed to determine whether TGF-beta levels could be a candidate marker for malarial infection or disease severity.

Automated summary

This study used a meta-analysis approach to investigate the difference in TGF-beta levels between different groups of malaria patients and healthy controls. The results showed that patients with uncomplicated malaria had lower TGF-beta levels compared to healthy controls, while there was no difference in TGF-beta levels between patients with severe malaria and patients with uncomplicated malaria.