Distúrbios mieloproliferativos associados ao estadiamento clínico da Leishmaniose Canina (LCan)

Abstract

The immune response in the various lymphoid compartments is a useful tool in the study of the progression of canine leishmaniasis (CanL). The bone marrow (B.M.), the primary lymphoid organ, is responsible for maintaining the cells of the erythroid, myeloid, lymphoid and platelet lineages. It is one of the preferred sites for the multiplication of amastigotes of Leishmania spp that can lead to ultrastructural changes in this organ, according to the progression of the disease. In CanL the B.M. it is generally evaluated only for its parasitism. The present study aimed to associate the findings of histology, immunohistochemistry (IHC) of B.M. and myelogram for the clinical staging of CanL proposed by the Study Group on Animal Leishmaniasis, BRASILEISH. Thirty-six dogs serologically positive for CanL were included in the retrospective study group (RG) for histological and IHC evaluation of ear skin and B.M. In the prospective study, sixty-four adult dogs with suspected CanL underwent clinical evaluation and had biological samples collected for investigation of CanL in vivo. Serological (ELISA), B.M. molecular (PCR) and B.M. parasitological analyzes were carried out (cytology) in addition to hemogram and serum biochemistry. From the RG in the histology of B.M. megakaryocytic dysplasias and/or emperiopolesis were seen in 17/36 (47.2%), histiocytic erythrophagocytosis in 9/36 (25%), marrow hypoplasia in 3/36 (8.3%), erythroid dysplasia 3/36 (8.3%) and presence of multinucleated epithelioid cells 1/36 (2.8%). At the IHC of B.M. 34/36 (97.2%) were positive and in the skin IHC 12/13 (92.3%). From the prospective study, 59/64 (92.2%) were serologically positive. The molecular diagnosis was confirmed in 8 48/64 (75%) and the parasitological diagnosis in 39/64 (60.9%). Anemia was present in 47/64 (73.4%), leukocytosis in 14/64 (21.9%), leukopenia in 3/64 (8.8%), thrombocytosis in 23/64 (35.9%) and thrombocytopenia in 5/64 (7.8%). They were classified in stage 0 (negative control) 5/64 (7.8%), I 5/64 (7.8%), II 26/64 (37.5%), III 20/64 (31.3 %), IV 4/64 (6.3%) and V 4/64 (6.3%). Under the conditions in which this experiment was conducted, and in the selected sample, it can be concluded that changes in the myelogram by LCan staging reflect on the peripheral count of erythrocytes and leukocytes. Here we demonstrate for the first time that RETIC can be used as a biomarker of CanL progression following the BRASILEISH guidelines. Eosinopenia and monocytopenia can act as biomarkers of severe CanL.