Serology in leprosy

A critical survey of the literature on serology in leprosy has shown that sera taken from lepromatous patients display some striking differences in comparison with sera from tuberculoid patients. The tests most frequently employed were complement-fixation, haemagglutination, electrophoresis, precipitation and immunofluorescence, together with a variety of antigens not only from lepromas but also from Mycobacterium tuberculosis and other actinomycetales.With the exception of the Rubino test, all these serological tests are lacking in specificity for leprosy since leprous sera have a broad range of reactivity with different antigens, including those employed in the serological diagnosis of syphilis.Some features of the leprous sera could be related to a hypersensitivity state involving circulating immune complexes, low levels of complement and the presence of antibodies similar to those found in sera from patients with autoimmune diseases.