Improving reproducibility of Plasmodium falciparum culture: a large-language-model-driven literature review and a parasite growth variability assessment of donor red blood cells.

BACKGROUND

In vitro culture of Plasmodium falciparum forms the basis for many key malaria research areas globally, yet the human red blood cells (RBC) essential for culture remain poorly characterized in most studies, despite growing evidence of substantial donor-dependent variability that can influence parasite growth and experimental outcomes.

METHODS

A dual investigation was performed comprising: (1) a large language model-assisted systematic review of 963 PubMed-indexed articles (2000-2025) to assess reporting of RBC sourcing in malaria culture studies; and (2) an experimental analysis of parasite growth variability using standardized P. falciparum strain 3D7 culture with RBC from 69 malaria-naïve volunteers, including detailed haematological profiling of 24 participants.

RESULTS

Among the 963 studies, 314 provided explicit information on the RBC source. Of these, 61.1% failed to specify donor origin, 72.6% omitted blood group information, and only 6.0% reported the anticoagulant used. Type O RBC were used in 54.7% of studies reporting the blood group, despite limited evidence for biological advantage. In the experimental cohort, parasite growth after 96 h varied 6.4-fold across volunteers (range: 3.0-19.3), with growth phenotypes reproducible over three years. Low-growth volunteers had lower haemoglobin concentrations (12.3 vs. 14.8 g/dL, p = 0.03), more frequent personal or family history of anaemia (p = 0.01), and greater ancestry from malaria-endemic regions (p = 0.03). However, extended laboratory testing failed to identify any consistent clinical or biochemical predictors of growth capacity.

CONCLUSIONS

Donor RBC are a major and reproducible source of biological variability in P. falciparum culture, yet are inconsistently reported and poorly understood. To address this, the STRuBeC (Standards for Reporting for use of (Red) Blood Cells in Culture) is proposed as a minimum reporting standard for studies using P. falciparum in vitro culture, to improve transparency, reproducibility, and cross-study comparability.