Study Identifies MT2A as a Novel Biomarker Linking Zinc Status to COVID-19 Mortality

The connection between zinc deficiency and poor COVID-19 outcomes has been documented across multiple clinical studies. Patients with COVID-19 demonstrate significantly lower zinc levels than healthy controls, and zinc deficiency correlates with greater disease severity. More recently, zinc deficiency has been independently associated with approximately 63% higher predicted odds of worse COVID-19 outcomes—a finding with direct implications for patient risk stratification and supportive care decisions.^1-3

What has remained less clear, however, is precisely how systemic zinc status gets "translated" inside cells into the immune dysfunction that drives mortality. A new study published in Targetome has taken a significant step toward answering that question.¹

A 2-Pronged Investigation: Meta-Analysis and Multi-Omics Profiling

Researchers at China Pharmaceutical University conducted a PRISMA-guided meta-analysis alongside an extensive multicompartment transcriptomic analysis to identify intracellular mediators of zinc-linked immune dysregulation in COVID-19.¹

In a meta-analysis of 7 studies totaling 1972 hospitalized patients with COVID-19, zinc supplementation was associated with a markedly lower risk of death, with an OR of 0.48 (95% CI, 0.36-0.64), low heterogeneity, and no evidence of publication bias. The result was robust across sensitivity analyses, but the researchers pushed further, using single-cell RNA sequencing (RNA-seq) and bulk RNA-seq data from blood, bronchoalveolar lavage fluid (BALF), sputum, and postmortem lung tissue to identify which molecular targets might explain this clinical benefit.⁴

MT2A Emerges as a Severity-Linked Signal Across Tissue Compartments

Among the zinc-homeostasis genes examined, MT2A, which encodes metallothionein 2A, a cysteine-rich protein responsible for intracellular zinc buffering and redox regulation, emerged as the most reproducible marker of COVID-19 severity. Metallothioneins regulate zinc homeostasis, mitigate oxidative stress, and have emerged as important, yet underappreciated, components of the innate immune response.²

In an analysis of over 1.4 million cells from 196 individuals, MT2A showed the highest expression in monocytes and macrophages, decreased in mild and moderate disease, and increased significantly in severe and critical progression. The pattern held across multiple tissue compartments—including BALF and sputum—supporting MT2A as a cross-compartment marker of metal/redox immune stress rather than an artifact of a single tissue type.^1,4

Temporal Dynamics: A Stage-Dependent Window for Intervention

One of the study's most pharmacologically relevant findings relates to timing. Longitudinal blood data indicated that MT2A peaks at day 1 postinfection and then declines, supporting MT2A as an early, stage-dependent marker of metal/redox immune stress. This temporal pattern, covarying with key innate immune genes including CTSL, TLR7, and IFIH1, suggests a narrow window during which biomarker-guided zinc interventions may carry the most benefit.⁴

Implications for Pharmacy Practice and Future Research

These findings have several implications for clinicians and pharmacists managing hospitalized patients with severe respiratory illness. Although zinc supplementation is already widely used as adjunctive therapy, the heterogeneity of dosing regimens in clinical practice—varying in formulation, elemental dose, route, and duration—has made it difficult to define best practices. Zinc deficiency has been associated with higher hospitalization and mortality rates in patients with COVID-19, particularly those with cardiac and renal comorbidities, suggesting that managing zinc levels could improve long-term outcomes.⁵

The identification of MT2A as a candidate biomarker offers a potential path toward more precise patient stratification. Rather than applying a one-size-fits-all supplementation approach, pharmacists and clinicians may eventually be able to use MT2A expression in circulating monocytes as an enrichment tool—identifying which patients are most likely to benefit from zinc intervention and at what stage of illness.¹

The study authors are careful to note that causal validation is still required. The transcriptomic associations are hypothesis-generating, and perturbation-based studies with controlled zinc conditions are needed before MT2A can be used clinically as a therapeutic target. Nevertheless, the convergence of clinical trial data and multi-omics evidence positions MT2A as one of the most promising host-directed nodes identified in postpandemic COVID-19 research to date.¹

REFERENCES

1. Li Z, Hua S, Song S, et al. Multi-omics integration identifies MT2A as a biomarker and a candidate host target linking zinc dysregulation to COVID-19 mortality. Targetome. 2026;2(1):e006. doi:10.48130/targetome-0026-0006

2. Jothimani D, Kailasam E, Danielraj S, et al. COVID-19: Poor outcomes in patients with zinc deficiency. Int J Infect Dis. 2020;100:343-349. doi:10.1016/j.ijid.2020.09.014

3. Mouchati C, Durieux JC, Zisis SN, et al. Zinc deficiency and sTNF-RII are associated with worse COVID-19 outcomes. J Nutr. 2024;154(5):1588-1595. doi:10.1016/j.tjnut.2023.11.026

4. Zinc, immune stress, and COVID-19: MT2A emerges as a cross-compartment marker linked to severity. News release. Maximum Academic Press. April 4, 2026. Accessed April 6, 2026. https://www.eurekalert.org/news-releases/1122818

5. Hung L, Liu M, Yu T, et al. Zinc deficiency and post-acute outcomes in patients with COVID-19: a six-month retrospective cohort analysis of 3,726 patients. Cureus. 2024;16(10):e71609. doi:10.7756/cureus.71609