Serum Levels of Zinc Transporter Proteins SLC30A5 and SLC30A6 in Patients with Psoriasis: A Cross-Sectional Study

Zinc transporter proteins (ZnTs) are crucial for maintaining cellular zinc homeostasis, and their dysregulation may play a role in inflammatory diseases. Among them, ZnT5 (SLC30A5) and ZnT6 (SLC30A6) are localized to the membranes of the endoplasmic reticulum and Golgi apparatus, organelles involved in cellular stress responses and the secretory pathway. Considering that endoplasmic reticulum stress is implicated in psoriasis, altered function of SLC30A5 and SLC30A6 may contribute to disrupted zinc handling in this disease. In this cross-sectional study, serum levels of SLC30A5 and SLC30A6 were measured in 50 psoriasis patients and 50 healthy controls using enzyme-linked immunosorbent assay (ELISA), and their diagnostic potential was evaluated through receiver operating characteristic (ROC) analysis. The results showed that mean serum levels of both SLC30A5 and SLC30A6 were significantly lower in patients compared to controls (SLC30A5: 6.8 ± 2.4 vs. 13.2 ± 6.1; SLC30A6: 5.4 ± 5.7 vs. 14.3 ± 11.5; p < 0.05), with ROC analysis demonstrating good discriminatory power (AUC: 0.76 for SLC30A5 and 0.80 for SLC30A6). Moreover, patients with low SLC30A6 levels tended to have an earlier disease onset and a higher prevalence of smoking. While the study was limited by its single-center design, relatively small sample size, and lack of genetic or tissue-level analyses, the findings suggest that reduced serum SLC30A5 and SLC30A6 levels may be involved in psoriasis pathophysiology and could serve as potential supportive biomarkers, pending confirmation in larger and mechanistic studies.