Serum auto antibodies and clinical/pathological features in German shepherd dogs with a lupuslike syndrome

This study presents 8 dogs of German Shepherd breed (6 males, 2 females, 2-5 years of age at onset of the disease) with a lupus like syndrome characterized by febrile polyarthritis, wasting, nephropathy, cutaneous lesions and high positive titres of ANA (antinuclear antibodies) of speckled type. The serum autoantibodies were further characterized by double immunodiffusion against ENA (extractable nuclear antigen), ELISA for Histone antibodies (Histon fraction H-24A and H-3S), indirect IF on rat-liver sections, non treated and RNase/DNase digested sections for DNP/RNP antibodies, and smears of a hemoflagellate C. luciliae for antibodies vs doubbel strained DNA, (dsDNA). Thus, the high ANA titres in these dogs represent varying types of autoantibodies against nucleoproteins of both DNA and RNA nature, associated histone antigens and non-histone antibodies (RNA and Sm) as well. Rheumatoid Factor titres in serum from these dogs were low or negative. Immunoglobulin deposits at dermo-epidermal junctions were demonstrated in some of the dogs with hyperkeratotic skin lesions. High concentration of serum-IgG was a constant finding in combination with anemia and in most cases leukopenia probably related to the chronic inflammatory process in these animals. Autoimmune hemolytic anemia (AIHA) or thrombocytopenia was not detected in these dogs.