We studied 75 cases of canine systemic lupus erythematosus (SLE) presenting with at least four criteria of the American Rheumatism Association (ARA), including antinuclear antibodies (ANAb). This disease mainly affects male German shepherds of an average age of 5 years. The most common clinical signs are polyarthritis (91% of cases), and renal (65%) and cutaneo-mucous disorders (60%). Hemolytic anemia is rare (13%). ANAb are present, often at high levels (> 256 up to 10(6) by indirect immunofluorescence on mouse blood smears). The titers are correlated with the severity and the stage of the disease. As double-stranded DNA Ab are rare and as antihistone Ab are frequent, the former could be replaced by the latter in the ARA criteria applied to the SLE dog. Another category of ANAb, named anti-type 1, also seems useful in diagnosing canine SLE. As for therapy, long-term remissions (up to 9 years without treatment) were obtained in 55.6% of 27 SLE dogs treated by levamisole. At first, levamisole was associated with induction corticotherapy, then administered alone and finally discontinued. Side effects were uncommon and transient.

The frequency and the specificities of antinuclear antibodies (ANAb) were studied in dogs with systemic lupus erythematosus (SLE) and compared to those found in normal dogs and in dogs with various infectious diseases. Whole ANAb were detected by immunofluorescence. Anti-double-stranded DNA Ab were found in only 2% of SLE dogs, whereas anti-single-stranded DNA Ab were present in 21.4% of SLE dogs and in 26.8% of dogs with infectious disease. Antihistone Ab were frequently observed in SLE dogs (71%) and are essentially directed against trypsin-resistant epitopes of H3, H4 and H2A. The Western blots of nuclear extracts of HeLa cells were recognized mainly by type 1 Ab (30%, reacting with bands of 43, 36, 35, 34, 30 and 27 kDa) and by anti-Sm Ab (12%) associated with anti-RNP Ab. Anti-SSA and anti-SSB Ab were rare.

The canine DLC 01 cell line derives from a lymph node of a dog with Sé zary syndrome. The DLC 01 cell phenotype is CD4 ؊ , CD8؉ , CD45 ؉ , DQ ؉ , similar to that of original cells after treatment with dimethylsulfoxide or phorbol myristate. Canine cutaneous T cell lymphoma are usually CD4Ϫ , CD8 ؉ in contrast to their human counterparts which are CD4 ؉ , CD8 ؊ . Therefore, the DLC 01 cell line appears to be a unique model to study the mechanism of all surface molecule expression in vitro. Viral particles with retrovirus type-C morphology were found in ultrathin sections of DLC 01 cell pellets. Retroviral particles are spontaneously produced after the 50th cell passage or after induction with 0.5% dimethylsulfoxide. This is the first description of a dog lymphoid cell line spontaneously growing and producing a retrovirus. It was found to share several features in common with feline and murine leukemia viruses.

This report describes two animals (one dog and one cat) with a retained surgical sponge. Both had nonspecific clinical signs. Clinical examination, ultrasonography and cytologic examination were used to identify an abdominal mass compatible with a granuloma. The lesions were surgically removed and confirmed histologically as granulomas secondary to a retained sponge. The ultrasonographic appearance was very similar in both animals.

Canine cutaneous histiocytoma (CCH), a histiocytic benign, dermal, self-healing tumor in the young dog, and epidermal Langerhans cells (LC) are thought to be related. In this study, we used immunohistochemical staining and transmission electron microscopy for 5 fresh CCH and 17 fixed tumors, to examine if, on the basis of their immunophenotype and their ultrastructural morphology, these tumor cells originate as LCs. The immunophenotype of CCH: canine CD 11a, lie, 18, 45, MHC II positive and ACM1, human CD 14 negative, was different from canine macrophage immunophenotype but very similar to the canine LC phenotype. Furthermore, we have described ultrastructural markers in CCH cells for the first time: these consist of coated vesicles, regularly laminated bodies, pleiomorphic inclusions, paracrystalline structures, and deep invaginations of the plasma membrane, usually observed in congenital self-healing histiocytosis, a human LC tumor, or occasionally observed in human LC. The occurrence of such immunophenotype and ultrastructural markers confirmed the common lineage of LCs and CCH cells.