Background: Acute rejection is an important risk factor for kidney graft loss. As evidence suggests that prolactin has important immunostimulatory properties, we conducted a randomized, prospective open trial in which bromocriptine, a drug suppressing prolactin secretion, was administered as an additive immunosuppressive drug after first cadaver kidney transplantation.
Methods: In the treatment group bromocriptine was given intramuscularly to 22 patients after their first kidney transplantation along with conventional immunosuppression (cyclosporin A, glucocorticoids). Twenty-three patients receiving only conventional immunosuppression served as control subjects. The incidence of acute graft rejections, graft losses, and infections was evaluated.
Results: Serum prolactin concentrations were slightly elevated above normal values before transplantation (32 +/- 5.3 ng/ml) and decreased to values between 13 and 16 ng/ml in the control group and were totally suppressed in the bromocriptine group. After 6 months of follow-up overall patient and allograft survival was 97.7% and 91% respectively. Acute rejection episodes occurred in 31 patients (77.5%): 15 in the bromocriptine group vs 20 in the control group (n.s.). In each group eight patients experienced a cytomegalovirus infection. The incidence of severe bacterial infections (i.e. pneumonia and sepsis) was five and six respectively. The necessity of haemodialysis after transplantation was 3.1% in the patients on bromocriptine and 23% in those without.
Conclusions: Suppression of circulating prolactin concentration by bromocriptine did not improve the clinical outcome of patients after kidney transplantation receiving cyclosporin and prednisolone.