A correlative study of serum zinc and in vivo cell mediated immune status in rheumatic heart disease

This study was conducted to determine the zinc status and assess relationship between serum zinc and in vivo cell mediated immunity (CMI) in patients with rheumatic heart disease (RHD). The study comprised 22 patients with active rheumatic heart disease (ARHD), 15 patients with chronic rheumatic heart disease without activity (CRHD) (selection based on Jone's Criteria--Revised), and 15 age and sex matched healthy control. Zinc estimation was done by atomic absorption spectrophotometer. To assess CMI in vivo, phytohaemagglutinin skin test and skin window test were done. Serum zinc and in vivo CMI in patients with ARHD and CRHD compared with controls. Mean serum zinc was significantly decreased in patients with ARHD and CRHD, more pronounced in the former (P less than 0.001); and mean 24 h urinary zinc was significantly increased in patients with ARHD (P less than 0.001) as compared to controls. A significant depression in CMI in vivo was observed in patients with ARHD and CRHD (P less than 0.001). A significant positive correlation was seen among serum zinc and markers of in vivo CMI (P less than 0.001). In conclusion, depletion of zinc, observed in RHD, probably causes immune alterations and suggest role of zinc in immunopathogenesis of RHD. Zinc supplementation may alter the course of rheumatic fever and RHD