The dynamics of IgM- and IgG-antibodies in leptospiral infection in man.

The dynamics of specific agglutinating antibodies belonging to different classes of immunoglobulins in 1047 blood sera of 669 patients and persons who had recovered from leptospirosis was studied. 19S and 7S antibodies were found in sera of patients with simultaneous presence of Pomona and Grippotyphosa. The character of syntesis of specific leptospiral IgM and IgG antibodies correlated, but the concentration of the IgG was much lower. As a rule, IgM antibodies had a wide range of cross-reactions with leptospires of heterologous serogroups. However, IgG-antibodies in 85% of cases reacted with homologous leptospires only.