PubMed Health⌕ Search

Biomedical subjects

L Chabanne

Publications and source records attributed to L Chabanne.

26 records · Page 2Linked to original sources
PubMed1995

Abnormalities of lymphocyte subsets in canine systemic lupus erythematosus.

Canine systemic lupus erythematosus (SLE) is a disease clinically very similar to its human counterpart. But so far, no study has reported an accurate evaluation of the lymphocyte subsets in the canine disease. Here, we present a study in which lymphocyte subsets have been evaluated in the peripheral blood of 20 dogs suffering from spontaneous systemic lupus erythematosus (SLE) in active and inactive phases, before and during treatment with prednisone and levamisole. 22 healthy dogs have been used as a control population. We show that canine SLE in active phases is associated with a several lymphopenia (1050 +/- 520 10(6) cells/l versus 2130 +/- 1 020 10(6) cells/l in controls). A striking finding is the imbalance of the CD4 and CD8 subsets (respectively 56.7 +/- 10.7% and 10.9 +/- 3.8% of CD4+ and CD8+ lymphocytes versus 40.5 +/- 11.5% and 18 +/- 4.4% in controls) and a strong activation of T-cells in active phases (64.1 +/- 16.9% of 2B3+ cells versus 46.5 +/- 16.7%). Moreover, we observed a persistence of the T subset imbalance during spontaneous evolution. In contrast, the treatment induced in dogs showing a good response the correction of CD4/CD8 ratio and no clinical manifestations, whereas in low responders no such improvements were observed. Thus, this work suggests that the main immunological imbalance seen in SLE could be associated with defective suppressor cells and provides further evidence of similarity of human and dog SLE.

Animals↗
PubMed1995

[Malignant lymphoma with medium-sized macronucleolated cells in the dog: involvement of an original cell from the marginal zone of the reactive lymph node].

Among the non-Hodgkin's malignant lymphomas of the dog, which are largely dominated by the centroblastic heterogeneous type, there is an original form of malignant lymphoma which is homogeneous and diffuse, with macronucleolated medium-sized cells. These cells seem to be morphologically very similar to those which constitute the majority population in the marginal zone of the secondary follicle of the lymph node in the dog, and which appear in the course of certain conditions: systemic lupus erythematosus, leishmaniasis, satellite lymph nodes in benign or malignant tumors. The aim of this study was twofold: on the one hand to establish, in the canine species, the identity of the lymphomatous cells and the reactive cells that make up the marginal zone, i.e. the filiation between the hyperplastic marginal zones and the macronucleolated malignant lymphoma with medium-sized cells, and, on the other hand, to compare this type of malignant lymphoma with those which are reputed to originate in the marginal zone in humans, for example the malignant lymphoma of the lymphoid tissue associated with the mucous membranes, and the monocytoid malignant B-cell lymphomas. Ninety four malignant lymphomas were observed between 1989 and 1994 at the Veterinary School in Lyon; these consisted of 71 cases showing medium or high-grade malignancy, 17 cases with small cells, of low-grade malignancy, and 6 cases of mycosis fungoides. Among the 71 cases of medium and high-grade malignancy, 8 were immunoblastic, 5 centroblastic homogeneous, 50 centroblastic heterogeneous, and 8 homogeneous with macronucleolated medium-sized cells. The methods used in these 94 cases were of a morphological type: cytology, histology, transmission microscopy and immunohistochemistry. The cytohistological, ultrastructural and immuno-phenotypical characteristics (CD3-, CIg-, Ki-67- phenotype) of the lymphomatous cells and the cells of the marginal zone were found to be identical, in the dog; this strongly suggests B-lineage cells which do not secrete cytoplasmic immunoglobulins and are not involved in the cell cycle. Finally, these cells seem to us to be morphologically very similar to the minority population described by Van den Oord in the marginal zone of the secondary follicles in the lymph node in humans, in certain reactive situations.

Animals↗
PubMed1993

IgM and IgA rheumatoid factors in canine polyarthritis.

IgM and IgA rheumatoid factor (RF) were detected by ELISA using a purified dog IgG as antigen in normal controls (N = 84), dogs with unclassified polyarthritis (N = 95), dogs with rheumatoid arthritis (RA) (N = 22), dogs with systemic lupus erythematosus (SLE) (N = 35), dogs with leishmaniasis or heart worm disease (N = 20) and dogs with pyometra (N = 16). Frequency and titre of IgM and IgA RF are low and comparable (P < 0.05) in dogs with unclassified polyarthritis or RA: respectively 24.2% and 27.3% for IgM RF and 21.0% and 18.2% for IgA RF; the mean titre being respectively 0.781 +/- 0.581 and 0.649 +/- 0.365 for IgM RF, and 0.774 +/- 1.331 and 0.740 +/- 1.169 for IgA RF. The frequencies of IgM and IgA RF are a little higher in dogs with SLE (IgM RF: 37.1%, IgA RF: 25.7%) and higher in dogs with leishmaniasis or heart worm disease (45.0% and 30.0%), especially in dogs with pyometra (68.7% and 37.5%). So, although dogs can produce IgM and IgA RF, these auto-antibodies are uncommon in dogs with RA. Furthermore, when RF are present their titre is much lower than in human RA.

Animals↗
PubMed1992

Canine systemic lupus erythematosus. I: A study of 75 cases.

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.

Animals↗
PubMed1992

Canine systemic lupus erythematosus. II: Antinuclear antibodies.

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.

Animals↗
PubMedDate not supplied

Canine monocytes express a receptor specific for murine Fc gamma 2a and Fc gamma 3 immunoglobulins.

Murine monoclonal antibodies (mAb) of IgM and IgG subclasses that do not bind to canine cells have been used to detect the expression of Fc receptors on canine peripheral blood mononuclear cells and the cell line MAXEY-DH82. Murine Ig of IgG2a and IgG3 isotypes bound specifically to canine peripheral blood monocytes and to MAXEY-DH82, whereas Ig of IgG1, IgG2b, and IgM did not. No other cell types, including resting and activated peripheral blood lymphocytes, expressed this canine Fc receptor (cFcR) specific for murine IgG2a and IgG3. MAXEY-DH82 was used to characterize this Fc gamma 2a/gamma 3 receptor. Binding of murine IgG2a and IgG3 is trypsin sensitive and partially suppressed by phosphatidyl inositol-phospholipase C (PI-PLC) treatment, indicating that this cFc gamma 2a/gamma 3 receptor is a lipid-anchored protein. Preincubation of MAXEY-DH82 with canine sera or canine IgG prevented the binding of murine gamma 2a/gamma 3 Ig, demonstrating that this receptor is a cFc receptor for canine IgG. The cFc gamma R expressed on canine monocytes and on MAXEY-DH82 is probably the analog of the murine and human Fc gamma RI. The specific expression of this analog by canine cells could be used in identifying and purifying canine monocytes.

Animals↗