Antireticular cytotoxic serum (ACS / ATsS)
ACS (in Russian-language usage ATsS, антиретикулярная цитотоксическая сыворотка) was prepared at the Bogomolets Institute in Kyiv from the late 1930s, distributed across Soviet medicine for diverse indications (anti-aging, postoperative recovery, fracture healing, infection, and tumour adjunct), and exported in popular accounts to Western Europe and the United States in the 1940s. Production ran on the bench protocol described in Bogomolets’s monograph: animal donor sensitised against human spleen and bone marrow homogenate, bled three to five days later, with the serum then administered to humans in small therapeutic doses. The pharmacological rationale (small-dose stimulation of the reticuloendothelial system) borrowed the form of contemporary low-dose immunological reasoning but did not survive controlled clinical evaluation in the late 1940s. After Bogomolets’s death in 1946 and the cool postwar Western evaluations, the serum quietly faded from the medical pharmacopoeia.