Effect of anti-CD4 monoclonal antibody administration on rat small bowel allograft survival and circulating leukocyte populations.
This study assessed the effect of an anti-rat CD4 monoclonal antibody (OX38) on heterotopic small bowel allograft rejection. Fully allogeneic small bowel transplants were performed in the PVG-to-DA-rat strain combination. Animals received either i) short course (days -1, 0 and 1) of 1 mg/kg per day OX38, ii) short course of 5 mg/kg per day or iii) extended course (days -2, -1, 0, 1, 2 and twice weekly thereafter) of 1 mg/kg per day. Both the high dose (13 days) and extended low-dose (12 days) courses prolonged graft survival compared to untreated control animals (7 days). The low-dose, short-course treatment had no effect. Similar regimens were given to animals that did not receive transplants and in which peripheral blood CD4+ cell counts fell to between 20 and 55 % of pretreatment levels and 20-30% of binding sites were blocked. In summary, anti-CD4 monoclonal antibody therapy delayed rejection of rat small bowel allografts; however, long-term survival was not achieved.
Division of Clinical Sciences (NGH), Clinical Sciences Centre, Northern General Hospital, Sheffield, UK.
M J
MJ
Bowles
A G
AG
Pockley
R F
RF
Wood
D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D015704:CD4 Antigens / Q000276:immunology*; D004305:Dose-Response Relationship, Drug; D006085:Graft Survival; D007421:Intestine, Small / Q000637:transplantation*; D007958:Leukocyte Count; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D016042:Transplantation, Heterotopic; D014184:Transplantation, Homologous / Q000276:immunology / Q000502:physiology*
D000911:Antibodies, Monoclonal; D015704:CD4 Antigens; C108170:OX-38 monoclonal antibody