Figure 1
Anti-HPV IgG responses in OPC patients and non-cancer controls in a Sri Lankan population. (A) Anti-HPV18L1 and (B) Anti-HPV16L1 IgG responses of the case and control groups. Each enclosed circle represents the mean of duplicate OD values at 415Â nm, of each serum sample. Long horizontal lines represent the cut-off values (the mean OD value at 415Â nm plus 2 standard deviations of the control group excluding outliers) and the short horizontal lines represent the mean values for HPV18L1 and HPV16L1 ELISA. Mean OD values obtained for test samples falling over and above this cut-off level were expressed as positive responses.