doi:10.1038/nindia.2012.67 Published online 7 May 2012
The concentration of two components influencing the body's inborn immunity —vitamin D and mannose binding lectin (MBL) — are altered during viral infections. Researchers have now found out that the concentration of vitamin D is high in secondary dengue hemorrhagic fever (DHF) while MBL deficiency can be associated with primary DHF.
MBL is a pattern recognition molecule that recognizes specific sugar molecules present on the surface of microorganisms such as the dengue virus. This is the first study that correlates the concentrations of vitamin D and MBL with immune status of dengue cases.
Researchers from the National Institute of Virology in Pune assessed plasma concentrations of vitamin D and MBL in 48 dengue fever (DF) cases (mild form of the dieseae) and 45 DHF cases (severe form) using ELISA based methods. They found that vitamin D concentrations were higher among both DF and DHF cases as compared to healthy controls. When the cases were classified into primary and secondary infections, secondary DHF cases had significantly higher concentrations of vitamin D as compared to secondary DF cases.
MBL concentrations were found to be lower in DHF cases as compared to DF cases. Although MBL levels were not different in DF and DHF cases based on immune status, the percentage of primary DHF cases having MBL levels lower than 500 ng/ml were less compared to primary DF cases.
The study would be helpful in determining disease progression and immune response in dengue fever.