Multi-omics integration identifies MT2A as a biomarker and a candidate host target linking zinc dysregulation to COVID-19 mortality

Identifying host programs that connect micronutrient biology to COVID-19 immunopathology may enable more precise host-directed strategies. Zinc deficiency is linked to worse outcomes, yet the intracellular mediators that couple metal/redox stress to disease severity remain unclear. In this study, a PRISMA-guided meta-analysis of zinc supplementation was performed in hospitalized COVID-19 (seven studies; 1,972 participants), and observed reduced mortality (OR 0.48, 95% CI 0.36–0.64). Statistical heterogeneity was low, although regimens varied substantially in formulation, elemental dose, route, and duration. The study then integrated single-cell and bulk transcriptomes across blood and respiratory compartments, to map zinc-homeostasis pattern across disease states. In a large single-cell atlas (GSE158055; 1,462,702 cells from 196 individuals) spanning PBMC, bronchoalveolar lavage fluid, sputum, in bulk RNA-seq from postmortem lung tissue (GSE183533), and longitudinal peripheral blood (GSE198449), MT2A showed the most reproducible association with disease severity among metallothioneins, and was enriched in myeloid lineages. Its associations were compartment- and state-dependent, and SARS-CoV-2–relevant entry/processing and innate-sensing are involved, including TMPRSS2, CTSB/CTSL, and RNA-sensing pathways. In a longitudinal subset with complete timepoints (n = 9; days 0, 1, 8, and 12), MT2A peaked early after infection and declined thereafter, consistent with an inducible acute-phase response. Together, these results prioritize MT2A as a cross-compartment marker of metal/redox immune stress and a testable host node for biomarker-guided stratification and intervention timing, pending perturbation-based causal validation.