Human dialysable leucocyte extracts (transfer factor) in interstitial pneumonia. A retrospective trial in immunodeficient patients.

Thirty-six cases of interstitial pneumonia in acquired immunodeficient states were treated with transfer factor (Dialysable Leukocyte Extract) and studied retrospectively. The criteria of efficacity of this treatment were: rapidity of immediate improvement, improvement after failure of other immunostimulant therapy and demonstration of a dose-related effect. The mechanism of the therapeutic action is unclear. There is no evidence in favour of "transfer" of cell mediated immunity. A non-specific mode of action (adjuvant effect, interferon synergy, proinflammatory action) seems much more likely.