Guidelines for immunotherapy of antigen-specific defects with transfer factor.

Dialyzable leukocyte extracts (DLE) containing transfer factor (TF) with documented specificity for one or more microbial antigens have shown previously variable clinical effectiveness in treating many infectious diseases caused by viruses, fungi, protozoa and mycobacteria. The efficacy has sometimes been strong, and at other times dubious, in treating patients with inherited or presumably "acquired" immunodeficiency diseases refractory to standard therapy. The recent development of assays for screening leukocyte donors of DLE, for monitoring recipients, and especially for determining the potency of various DLE preparations containing antigen-specific TF and for predicting the clinical course of disease have, in our hands, greatly improved the likelihood of successful immunotherapy with TF. Two representative cases are reported, one involving a patient with an antigen selective defect to Candida, and another involving a patient with an antigen selective defect to Mycobacterium fortuitum. Both patients responded as judged by laboratory tests and clinical improvement when treated with certain DLE preparations but not with others. Finally, certain DLE preparations appeared to suppress cell-mediated immunity in vivo and this suppression could be predicted by in vitro tests. Based on these results, guidelines for optimal therapy with DLE are proffered .