Protracted severe immune dysregulation induced by cardiopulmonary bypass: a predisposing etiologic factor in blood transfusion-related AIDS?

A large percentage of patients with blood transfusion related AIDS received their transfusion during cardiac surgery requiring cardiopulmonary bypass. We hypothesized that the procedure of cardiopulmonary bypass (CPB) in patients undergoing cardiac surgery might be associated with severe immune dysregulation and hence predispose this group in particular to the acquisition of blood transfusion transmitted AIDS. T-cell subset enumeration and their ratio (T4/T8) and T-cell function (local GVH reaction) were serially studied before, during, and 1 and 6 days after surgery in 15 patients undergoing cardiac surgery requiring CPB, in 10 patients undergoing cancer resections (CA), and 11 patients without cancer undergoing elective, non-cardiac general surgical procedures (GEN). Compared to the preoperative values, a significant decline (p less than 0.002) in T4/T8 ratios occurred during CPB (1.63 +/- 0.80 vs 2.55 +/- 0.95), during CA (1.26 +/- 0.71 vs 1.81 +/- 0.72), and during GEN procedures (1.18 +/- 0.59 vs 1.64 +/- 0.68). T4, T8, and T4/T8 ratios returned to preoperative values in both the CA and GEN groups by the first postoperative day; in contrast, T4/T8 ratios remained significantly depressed (p less than 0.05) in CPB patients on the first and also on the sixth postoperative days when compared to preoperative values. This sustained depression in T4/T8 ratios is attributable to a significant increase in the proportion of T8 (suppressor cell) subset in the CPB patients which persisted through the sixth postoperative day. In contrast, in CA and GEN, the proportion of T8 subset returned to the preoperative level by the sixth postoperative day.(ABSTRACT TRUNCATED AT 250 WORDS)