Objective: To study the relationship between interleukin-2 (IL-2), soluble interleukin-2 receptor (sIL-2R) and the non-and-hypo-responsiveness to hepatitis B vaccine.
Methods: Peripheral blood mononuclear cells (PBMC) isolated from 21 non-and -hypo-responders, 22 hyperresponders and 21 chronic HBsAg carriers were incubated in the presence of HBsAg and phytohaemagglutinin (PHA). The levels of IL-2 and sIL-2R in the supernatants of activated cells were measured by an enzyme-linked immunosorbent assay.
Results: The average level of IL-2 in the non-and-hypo-responders was significantly lower than that in the hyperresponders (t=8.80, P<0.001), but was comparable to that in chronic HBsAg carriers (q=0.06, P>0.5). Between the hyperresponders and the non-and-hypo-responders, the average sIL-2R levels showed no noticeable difference.
Conclusion: The results suggest that low level of IL-2 may be one of the causes and mechanisms of non-and-hypo-responsiveness to hepatitis B vaccine.