pone-0027679-g002: Clinical findings of forty-eight dogs naturally infected with Leishmania (L.) infantum, Belo Horizonte, Minas Gerais, Brazil.

Mentions: After physical clinical analysis, thirty six dogs (75%) were within the normal weight range (considering breed), nine (18.75%) had abnormal weight classified with cachexia and three (6.25%) had emaciation. Cervical, popliteal and submandibular lymph node enlargement was present in 26 (54.16%), 26 (54.16%) and 11 (22.91%) dogs, respectively. Moreover, 21 (43.75%) dogs had at least two lymph nodes changed and ten (20.83%) had involvement of three lymph nodes simultaneously. Dermatological examination demonstrated that 46 (95.83%) dogs had at least one dermatological alteration and 32 (66.7%) had at least two alterations simultaneously. Other clinical remarks with clinical importance were the ophthalmic alterations in 21 dogs (43.75%) (Figure 2). The study of erythrocyte values in dogs naturally infected with L. infantum demonstrated that 16 (33.33%) of 48 animals had changes in the functional status of eritron, being that all of which were below the reference limits for the three parameters analyzed: circulating red blood cell (RBC), hematocrit and hemoglobin. When these parameters were evaluated by considering the mean corpuscular volume and hemoglobin concentration, anemia was classified as: normocytic normochromic in 14 of 16 dogs (87.5%) and normocytic hypochromic in two of 16 dogs (12.5%) analyzed. In addition, thrombocytopenia was observed in 6 of 16 dogs (37.5%). Eight other animals had thrombocytopenia without changes in eritron values. Therefore, thrombocytopenia was present in 14 of 48 dogs (29.2%). The creatinine levels were increased only two infected dogs (4.16%), but the urea values were increased in 42 dogs (85.42%). Serum liver enzymes alamine aminotransferase (ALT) and aspartate aminotransferase (AST), indicators of hepatocellular injury, had normal levels in all dogs analyzed, whilst, alkaline phosphatase (AF), an indicator of cholestasis, was increased in 11 of the 48 infected dogs (22.91%). Disproteinemia was observed in 25 of 48 infected dogs (52.1%), evidenced by hyperproteinemia and hypoproteinemia in 23 (47.91%) and two (4.12%) dogs, respectively. Furthermore, the albumin/globulin ratio was altered in 34 dogs (70.83%) when considering A/G ≤0.6, the prognostic critical value for disease development, and in five dogs (10.42%) when considering ≤0.7 A/G <0.8. Hypergammaglobulinemia was observed in 23 of 48 infected dogs (47.92%) and hypoalbuminemia in 17 (35.42%), and both parameters were simultaneously observed in 12 dogs (25.0%).

Amorim IF, Silva SM, Figueiredo MM, Moura EP, Castro RS, Lima TK, Gontijo Nde F, Michalick MS, Gollob KJ, Tafuri WL - PLoS ONE (2011)

Bottom Line: IHQ ear skin tissue parasite load and XENO where done where we found a strict correlation (r = 0.5373).Comparable results were obtained for MFI of MHCII (p = 0.0054).These data, together with the TLR2 and NO assays results (CD11b⁺TLR2⁺ and NO with higher values for dogs with IHQ⁻/XENO⁻ than dogs with IHQ⁺/XENO⁺, led to the conclusion that IHQ⁻/XENO⁻ dogs are more resistant or could modulate the cellular immune response essential for Leishmania tissue clearance.

Affiliation: Departamento de Patologia Geral, Escola de Medicina, Universidade Federal de Minas Gerais, Minas Gerais, Brasil.

Abstract: The aim of the present study was to investigate TLR2 expression in peripheral blood monocytes from dogs naturally infected with Leishmania (Leishmania) infantum to determine whether it correlates with CD11b/CD18 (CR3) expression, and to evaluate the potential of dogs as sources of infection using phlebotomine xenodiagnosis. Forty eight dogs were serologically diagnosed with L. infantum infection by indirect immunofluorescence antibody test (IFAT) and enzyme linked immunosorbent assay (ELISA). Parasitological exams from bone-marrow aspirates were positive by PCR analysis. All dogs were clinical defined as symptomatic. Ear skin tissue samples were obtained for immunohistochemistry (IHQ) analysis. The potential of these dogs as a source of infection using phlebotomine xenodiagnosis (XENO) was evaluated. Flow cytometry was carried out on peripheral blood mononuclear cells using superficial receptors including CD14, CD11b, TLR2 and MHCII. IHQ ear skin tissue parasite load and XENO where done where we found a strict correlation (r = 0.5373). Dogs with higher expression of MFI of CD11b inside CD14 monocytes were represented by dogs without parasite ear tissue load that were unable to infect phlebotomines (IHQ⁻/XENO⁻). Dogs with lower expression of MFI of CD11b inside CD14 monocytes were represented by dogs with parasite ear tissue load and able to infect phlebotomines (IHQ⁺/XENO⁺) (p = 0,0032). Comparable results were obtained for MFI of MHCII (p = 0.0054). In addition, considering the population frequency of CD11b⁺TLR2⁺ and CD11b⁺MHCII⁺, higher values were obtained from dogs with IHQ⁻/XENO⁻ than dogs with IHQ⁺/XENO⁺ (p = 0.01; p = 0.0048, respectively). These data, together with the TLR2 and NO assays results (CD11b⁺TLR2⁺ and NO with higher values for dogs with IHQ⁻/XENO⁻ than dogs with IHQ⁺/XENO⁺, led to the conclusion that IHQ⁻/XENO⁻ dogs are more resistant or could modulate the cellular immune response essential for Leishmania tissue clearance.