RT Journal A1 Damjanovic VV T1 Hemophiliacs with hiv seroconversion associated with heat-treated products: Are they actively infected? JF JAMA JO JAMA YR 1989 FD March 3 VO 261 IS 9 SP 1275 OP 1275 DO 10.1001/jama.1989.03420090039010 UL http://dx.doi.org/10.1001/jama.1989.03420090039010 AB To the Editor. —  Jackson et al1 recently provided evidence that hemophiliacs with human immunodeficiency virus (HIV) type 1 antibody are actively infected. They studied antibody-positive hemophiliacs who received non-heat-treated factor VIII or IX concentrates. However, cases of HIV seroconversion associated with use of heat-treated lyophilized products also have been reported.2 I recently postulated that a majority of such cases have not been infected but have been immunized by preserved viral proteins.3 This is based on experimental evidence of selective inactivation of the infectivity of dried, enveloped viruses by heat4 and a theoretical consideration of dry heat inactivation.5 Briefly, calculated differences in the energy that governs rates in the dry state for the thermal death of microorganisms (ΔG‡ 89.5 kJ/mol) and protein denaturation (ΔG‡ 126.8 kJ/mol) are significant,5 clearly indicating that heating of dry viruses may effectively inactivate them without affecting their