Analysis of the kinetic parameters of the antibody-catalyzed histone hydrolysis reaction showed that the Km values for the histone H1 hydrolysis (2.8–4.8 μM) are comparable with those for IgG of MS patients cleaving histone H1 (4.0–6.7 μM) [39] and for IgGs of HIV-infected patients (1.0–5.6 μM) [42], which indicates comparable affinity of IgGs of patients with schizophrenia compared to IgGs of patients with HIV infection and MS. This evidence concerns the gene H1-0 and HIV infectious disease.