Pattern of pre-existing IgG subclass responses to a panel of asexual stage malaria antigens reported during the lengthy dry season in Daraweesh, Sudan.

The anti-malarial IgG immune response during the lengthy and dry season in areas of low malaria transmission as in Eastern Sudan is largely unknown. In this study, ELISA was used for the measurement of pre-existing total IgG and IgG subclasses to a panel of malaria antigens, MSP2-3D7, MSP2-FC27, AMA-1 and Pf332-C231. The results showed that the antibody responses were predominantly age dependent, antigen specific, and their lifespan was at least 5-6 month long. Generally, the IgG3 was most abundant IgG subclass, and the most recognized antigen was Pf332-C231. Furthermore, the correlation between the levels of IgG subclasses was strongest between IgG1 and IgG3, which were more predictive to the total IgG levels. Finally, the response pattern of each of the IgG subclasses to the different test antigens that were spanning the dry season and the correlation between these responses were described in details for the first time.