EFFECTS OF RECOMBINANT INTERLEUKIN-2 AND REVACCINATION FOR HEPATITIS-B IN PREVIOUSLY VACCINATED, NONRESPONDER, CHRONIC UREMIC PATIENTS

Background. Growing evidence suggests that it is possible to seroconve rt chronic renal failure patients who are absolute non-responders to h epatitis B vaccine by means of either additional booster vaccine doses or associated IL-2 administration or both. We have studied the possib ilities of hepatitis B seroconversion by revaccination and its depende nce on vaccine dose, and the effects of a concurrent low-dose rHuIL-2 regime. Methods. Forty known absolute non-responders with chronic rena l failure were entered into a complete revaccination protocol. Patient s were randomly assigned to two dosage groups of either 20 or 40 mu g hepatitis B vaccine administered at 0, 1, 2 and 6 months. Further rand omly selected patients from each dosage group were given 500 000 U of rHuIL-2 in the same deltoid area 4 h after vaccine administration. Res ults. Sixty-seven per cent of patients revaccinated with 40 mu g attai ned antibody protecting levels compared to only 20% of those receiving doses of 20 mu g (P<0.025). When compared with initial values, the Th -CD4/CD25 cell count was significantly reduced immediately after HuR-I L2 administration (P<0.0003) and significantly increased 1 month after the last dose was given (P < 0.0003). A definite rHuIL-2 effect on HB V antibody synthesis could not be demonstrated, nor was erythropoietin found to enhance seroconversion. Conclusions. From these results we s uggest that more intense and frequent antigenic stimulation as obtaine d by revaccination using four doses of 40 mu g may effectively reduce the pool of hepatitis B vaccine nonresponders in chronic renal failure patients.