Frequency of detection and load of amastigotes in the pancreas of Leishmania infantum-seropositive dogs: clinical signs and histological changes

Abstract Background Zoonotic visceral leishmaniasis is caused by the protozoan Leishmania infantum and is highly lethal in humans and dogs if left untreated. The frequency of this parasite and associated histological changes in the pancreas of dogs are poorly studied. Therefore, the objectives of this study were to evaluate the frequency of detection and load of amastigotes in the pancreas of L. infantum-seropositive dogs and to identify the clinical signs and histological changes associated with parasitism of this organ. Methods One hundred forty-three dogs from an endemic area in Brazil that tested seropositive for L. infantum were studied. The dogs were clinically examined, killed, and necropsied between 2013 and 2014. One fragment of the pancreas was randomly collected for histopathology and immunohistochemistry, and spleen and bone marrow were collected for culture. Results Leishmania amastigotes were detected in the pancreas of 22 dogs (15.4%) by immunohistochemistry, all exhibiting L. infantum parasitism in the spleen and/or bone marrow. Poor body condition and cachexia were only associated with infection of the pancreas with Leishmania spp. (p = 0.021) and were found in 40.9% of dogs with pancreatic infection. Anorexia, vomiting, and/or diarrhea were observed in 9.2% of dogs with pancreatitis. The median parasite load in the pancreas was 1.4 infected macrophages/mm2. Pancreatic histological changes and their frequencies were: granulomatous pancreatitis (28.0%), lymphoplasmacytic pancreatitis (23.8%), acinar cell degeneration (6.3%), fibrosis (5.6%), hemorrhage (2.1%), eosinophilic pancreatitis (0.7%), suppurative pancreatitis (0.7%), and necrosis (0.7%). Conclusions The present results demonstrate that L. infantum is one of the etiological agents of chronic pancreatitis in dogs; however, the frequency of detection and parasite load are low in this organ. The lack of an association of poor body condition and cachexia with pancreatitis and the low frequency of clinical signs commonly associated with pancreatitis suggest that a significant portion of the organ is not affected by this parasite. On the other hand, the association of poor body condition and cachexia with concomitant infection of the pancreas, spleen, and/or bone marrow with this parasite suggests that these manifestations are the result of a more advanced stage of canine visceral leishmaniasis. Graphic abstract

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Frequency of co-seropositivities for certain pathogens and their relationship with clinical and histopathological changes and parasite load in dogs infected with Leishmania infantum

PLoS ONE ◽

10.1371/journal.pone.0247560 ◽

2021 ◽

Vol 16 (3) ◽

pp. e0247560

Author(s):

Valéria da Costa Oliveira ◽

Artur Augusto Velho Mendes Junior ◽

Luiz Claudio Ferreira ◽

Tatiana Machado Quinates Calvet ◽

Shanna Araujo dos Santos ◽

...

Keyword(s):

Bone Marrow ◽

Leishmania Infantum ◽

Dirofilaria Immitis ◽

Clinical Signs ◽

Parasite Load ◽

Inflammatory Cells ◽

Canine Leishmaniosis ◽

Conventional Pcr ◽

Serum Samples ◽

Histological Changes

In canine leishmaniosis caused by the protozoan Leishmania infantum, little is known about how co-infections with or co-seropositivities for other pathogens can influence aggravation of this disease. Therefore, the objectives of this study were to evaluate the frequency of co-infections with or co-seropositivities for certain pathogens in dogs seropositive for L. infantum and their relationship with clinical signs, histological changes and L. infantum load. Sixty-six L. infantum-seropositive dogs were submitted to clinical examination, collection of blood and bone marrow, culling, and necropsy. Antibodies against Anaplasma spp., Borrelia burgdorferi sensu lato, Ehrlichia spp. and Toxoplasma gondii and Dirofilaria immitis antigens were investigated in serum. Samples from different tissues were submitted to histopathology and immunohistochemistry for the detection of Leishmania spp. and T. gondii. Quantitative real-time PCR was used to assess the L. infantum load in spleen samples. For detection of Coxiella burnetii, conventional PCR and nested PCR were performed using bone marrow samples. All 66 dogs tested positive for L. infantum by qPCR and/or culture. Fifty dogs (76%) were co-seropositive for at least one pathogen: T. gondii (59%), Ehrlichia spp., (41%), and Anaplasma spp. (18%). Clinical signs were observed in 15 (94%) dogs monoinfected with L. infantum and in 45 (90%) dogs co-seropositive for certain pathogens. The L. infantum load in spleen and skin did not differ significantly between monoinfected and co-seropositive dogs. The number of inflammatory cells was higher in the spleen, lung and mammary gland of co-seropositive dogs and in the mitral valve of monoinfected dogs. These results suggest that dogs infected with L. infantum and co-seropositive for certain pathogens are common in the region studied. However, co-seropositivities for certain pathogens did not aggravate clinical signs or L. infantum load, although they were associated with a more intense inflammatory reaction in some organs.

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Morphological Changes in the Bone Marrow of the Dogs with Visceral Leishmaniasis

Veterinary Medicine International ◽

10.1155/2014/150582 ◽

2014 ◽

Vol 2014 ◽

pp. 1-5 ◽

Cited By ~ 10

Author(s):

Claudia Momo ◽

Ana Paula Prudente Jacintho ◽

Pamela Rodrigues Reina Moreira ◽

Danísio Prado Munari ◽

Gisele Fabrino Machado ◽

...

Keyword(s):

Bone Marrow ◽

Visceral Leishmaniasis ◽

Morphological Changes ◽

Clinical Signs ◽

Parasite Load ◽

Systemic Circulation ◽

Clinical Group ◽

Leishmania Chagasi ◽

Control Center ◽

A Site

The aim of this study was to evaluate the most frequent lesions in the bone marrow of dogs naturally infected byLeishmania (Leishmania) chagasi.Thirty-three dogs sacrificed at the Zoonosis Control Center of Araçatuba, a municipality endemic for visceral leishmaniasis (VL), were used. The animals were classified as asymptomatic, oligosymptomatic, and symptomatic groups. At the necropsy, bone marrow samples were collected from the femur, fixed, processed, and stained with hematoxylin and eosin. The lesion intensity was classified as mild, moderate, or severe. The parasite load was determined using immunohistochemistry. The most important lesions consisted of multifocal to diffuse granulomas, megakaryocytic dysplasia, and medullary aplasia. There were no statistical differences between the three clinical groups regarding parasite load and lesion intensity. Asymptomatic dogs also presented high parasitism in the bone marrow as dogs with clinical signs of VL. It was concluded that, regardless of clinical group, the bone marrow is a site for multiplication ofLeishmania chagasi. Possibly, the bone marrow dysplasia may arise from the presence of many parasitized and activated macrophages in this organ. Consequently, it affects the profile of hematopoietic cells in the bone marrow and systemic circulation.

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Correlations between tissue parasite load and common clinical signs in dogs naturally infected by Leishmania infantum

Veterinary Parasitology ◽

10.1016/j.vetpar.2021.109368 ◽

2021 ◽

Vol 291 ◽

pp. 109368

Author(s):

Úrsula Maira Russo Chagas ◽

Daniel Moreira de Avelar ◽

Andreza Pain Marcelino ◽

Gustavo Fontes Paz ◽

Célia Maria Ferreira Gontijo

Keyword(s):

Leishmania Infantum ◽

Clinical Signs ◽

Parasite Load

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Experimental Evaluation of Second-Line Oral Treatments of Visceral Leishmaniasis Caused by Leishmania infantum

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.43.1.172 ◽

1999 ◽

Vol 43 (1) ◽

pp. 172-174 ◽

Cited By ~ 34

Author(s):

Jean-Pierre Gangneux ◽

Michael Dullin ◽

Annie Sulahian ◽

Yves Jean-Francois Garin ◽

Francis Derouin

Keyword(s):

Visceral Leishmaniasis ◽

Murine Model ◽

Experimental Evaluation ◽

Leishmania Infantum ◽

Parasite Load ◽

Second Line ◽

Meglumine Antimoniate ◽

Marked Activity

ABSTRACT In a murine model of Leishmania infantum visceral leishmaniasis, metronidazole, ketoconazole, fluconazole, itraconazole, and terbinafine were less effective than antimonial agents in reducing hepatic parasite load. Ketoconazole potentiated the effect of meglumine antimoniate reference therapy through its marked activity against spleen infection.

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T cell suppression in the bone marrow of visceral leishmaniasis patients: impact of parasite load

Clinical & Experimental Immunology ◽

10.1111/cei.13074 ◽

2017 ◽

Vol 191 (3) ◽

pp. 318-327 ◽

Cited By ~ 3

Author(s):

P. Kumar ◽

P. Misra ◽

C. P. Thakur ◽

A. Saurabh ◽

N. Rishi ◽

...

Keyword(s):

Bone Marrow ◽

T Cell ◽

Visceral Leishmaniasis ◽

Parasite Load ◽

T Cell Suppression ◽

Cell Suppression

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Is severe visceral leishmaniasis a systemic inflammatory response syndrome? A case control study

Revista da Sociedade Brasileira de Medicina Tropical ◽

10.1590/s0037-86822010000400010 ◽

2010 ◽

Vol 43 (4) ◽

pp. 386-392 ◽

Cited By ~ 48

Author(s):

Carlos Henrique Nery Costa ◽

Guilherme Loureiro Werneck ◽

Dorcas Lamounier Costa ◽

Thiago Ayres Holanda ◽

Guilherme Brasileiro Aguiar ◽

...

Keyword(s):

Risk Factors ◽

Bone Marrow ◽

Visceral Leishmaniasis ◽

Systemic Inflammatory Response Syndrome ◽

Bacterial Infection ◽

Case Control Study ◽

Parasite Load ◽

Case Control ◽

Severe Anemia ◽

Control Study

INTRODUCTION: The objective of the study is to identify the main risk factors for death by New World visceral leishmaniasis and establish a coherent pathogenic substrate of severe disease based on clinical findings. METHODS: Seventy-six deceased inpatients and 320 successfully treated inpatients with VL were studied in a case control study. RESULTS: Bacterial infection and bleeding were mutually exclusive events leading to death. Five risk factors were unique for death by bacterial infection (malnutrition, pulmonary rales, severe anemia, severe absolute neutropenia and higher neutrophil count), while another six were unique for death by bleeding (jaundice, severe relative neutropenia, severe thrombocytopenia, liver injury, kidney failure, higher bone marrow parasite load). Bacterial infection, bleeding, severe anemia, diarrhea, dyspnea, edema, jaundice and bone marrow parasite load were the main syndromes of visceral leishmaniasis among successfully treated patients. CONCLUSIONS: The data support the idea that bacterial infections are due to immune paralysis. Broad organ and system involvement is plausibly due to the high production of proinflammatory cytokines, whose actions fit well with visceral leishmaniasis. The syndromes and causative mediators are typical of a slowly developing systemic inflammatory response syndrome.

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Hematological profile in visceral leishmaniasis

International Journal of Infection and Microbiology ◽

10.3126/ijim.v2i2.8320 ◽

2013 ◽

Vol 2 (2) ◽

pp. 39-44 ◽

Cited By ~ 3

Author(s):

Y Agrawal ◽

AK Sinha ◽

P Upadhyaya ◽

SU Kafle ◽

S Rijal ◽

...

Keyword(s):

Bone Marrow ◽

Visceral Leishmaniasis ◽

Plasma Cells ◽

Parasite Load ◽

Clinical History ◽

Bone Marrow Examination ◽

Severe Form ◽

P Value ◽

Cross Sectional ◽

Haematological Profile

INTRODUCTION: Visceral Leishmaniasis is the most severe form of leishmaniasis and can be fatal in the absence of treatment. Nepal, India, Bangladesh, Brazil and Sudan constitute five countries of the world where more than 90% of visceral leishmaniasis occurs. The aim of this study is to evaluate haematological profile with available clinical data in visceral leishmaniasis patients and to detect LD bodies among them. MATERIALS AND METHODS: It is a hospital based cross sectional study conducted in the Department of Pathology, BPKIHS, Dharan, for the period of one year. LD bodies were calculated in bone marrow aspirate of forty clinically suspected cases by counting the number of parasites per 100 consecutive oil immersion fields. RESULTS: The age ranged from 2-60 years. Pyerxia was the most common sign (100%) followed by splenomegaly (82.5%), hepatomegaly (65%), and pallor (75%). Anemia was present in 90%, leucopenia in 67.5% and thrombocytopenia in 72.5% cases. Bicytopenia and pancytopenia were observed in 40% and 25% cases, respectively. On peripheral examination RBCs were predominantly normocytic normochromic. On bone marrow examination normocellular marrow and megaloblastic features were predominant findings followed by increased plasma cells. Low, moderate and high grade LD bodies were present in 7.5%, 37.5% and 55% of the cases respectively. Hepatomegaly, anemia, neutropenia and lymphocytosis were statistically significant to parasite load (p-value <0.05). CONCLUSIONS: Besides LD bodies in bone marrow aspirates, dyserythroblastic changes and increase plasma cells are common findings in leishmaniasis. Patient from endemic area with positive clinical history and findings should be examined for LD bodies in marrow if dyserythroblastic and increase plasma cell picture is found. DOI: http://dx.doi.org/10.3126/ijim.v2i2.8320 Int J Infect Microbiol 2013;2(2):39-44

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Efficacy of Combined Therapy with Liposome-Encapsulated Meglumine Antimoniate and Allopurinol in Treatment of Canine Visceral Leishmaniasis

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00208-12 ◽

2012 ◽

Vol 56 (6) ◽

pp. 2858-2867 ◽

Cited By ~ 35

Author(s):

Sydnei M. da Silva ◽

Izabela F. G. Amorim ◽

Raul R. Ribeiro ◽

Erly G. Azevedo ◽

Cynthia Demicheli ◽

...

Keyword(s):

Bone Marrow ◽

Visceral Leishmaniasis ◽

Drug Combination ◽

Combined Therapy ◽

Combined Treatment ◽

Parasite Load ◽

The Other ◽

Sand Flies ◽

Content Type ◽

Meglumine Antimoniate

ABSTRACTAn innovative liposomal formulation of meglumine antimoniate (LMA) was recently reported to promote both long-term parasite suppression and reduction of infectivity to sand flies in dogs with visceral leishmaniasis. However, 5 months after treatment, parasites were still found in the bone marrow of all treated dogs. In order to improve treatment with LMA, the present study aimed to evaluate its efficacy in combination with allopurinol. Mongrel dogs naturally infected withLeishmania infantumwere treated with six doses of LMA (6.5 mg Sb/kg of body weight/dose) given at 4-day intervals, plus allopurinol (20 mg/kg/24 hper os) for 140 days. Comparison was made with groups treated with LMA, allopurinol, empty liposomes plus allopurinol, empty liposomes, and saline. Dogs remained without treatment from day 140 to 200 after the start of treatment. The drug combination promoted both clinical improvement of dogs and significant reduction in the parasitic load in bone marrow and spleen on days 140 and 200 compared to these parameters in the pretreatment period. This is in contrast with the other protocols, which did not result in significant reduction of the bone marrow parasite load on day 200. Strikingly, the combined treatment, in contrast to the other regimens, induced negative quantitative PCR (qPCR) results in the liver of 100% of the dogs. Both xenodiagnosis and skin parasite determination by qPCR indicated that the drug combination was effective in blocking the transmission of skin parasites to sand flies. Based on all of the parasitological tests performed on day 200, 50% of the animals that received the combined treatment were considered cured.

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Clinical recovery of Macaca fascicularis infected with Plasmodium knowlesi

10.1101/2021.06.28.448877 ◽

2021 ◽

Author(s):

Mariko S. Peterson ◽

Chester J Joyner ◽

Jessica A. Brady ◽

Jennifer S Wood ◽

Monica Cabrera-Mora ◽

...

Keyword(s):

Bone Marrow ◽

Tissue Damage ◽

Macaca Fascicularis ◽

Plasmodium Knowlesi ◽

Clinical Signs ◽

Parasite Load ◽

Blood Chemistry ◽

Severe Anaemia ◽

Chronic Infections ◽

Tissue Samples

Background Kra monkeys (Macaca fascicularis), a natural host of Plasmodium knowlesi, control parasitaemia caused by this parasite species and escape death without treatment. Knowledge of the disease progression and resilience in kra monkeys will aid the effective use of this species to study mechanisms of resilience to malaria. This longitudinal study aimed to define clinical, physiological and pathological changes in kra monkeys infected with P. knowlesi, which could explain their resilient phenotype. Methods Kra monkeys (n = 15, male, young adults) were infected intravenously with cryopreserved P. knowlesi sporozoites and the resulting parasitaemias were monitored daily. Complete blood counts, reticulocyte counts, blood chemistry and physiological telemetry data (n = 7) were acquired as described prior to infection to establish baseline values and then daily after inoculation for up to 50 days. Bone marrow aspirates, plasma samples, and 22 tissue samples were collected at specific time points to evaluate longitudinal clinical, physiological and pathological effects of P. knowlesi infections. Results As expected, the kra monkeys controlled parasitaemia and remained with low-level, persistent parasitaemias without antimalarial intervention. Unexpectedly, early in the infection, fevers developed, which ultimately returned to baseline, as well as mild to moderate thrombocytopaenia, and moderate to severe anaemia. Mathematical modeling and the reticulocyte production index indicated that the anaemia was largely due to the removal of uninfected erythrocytes and not impaired production of erythrocytes. Mild tissue damage was observed, and tissue parasite load was associated with tissue damage even though parasite accumulation in the tissues was generally low. Conclusions Kra monkeys experimentally infected with P. knowlesi sporozoites presented with multiple clinical signs of malaria that varied in severity among individuals. Overall, the animals shared common mechanisms of resilience characterized by controlling parasitaemia 3-5 days after patency, and controlling fever, coupled with physiological and bone marrow responses to compensate for anaemia. Together, these responses likely minimized tissue damage while supporting the establishment of chronic infections, which may be important for transmission in natural endemic settings. These results provide new foundational insights into malaria pathogenesis and resilience in kra monkeys, which may improve understanding of human infections.

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Spectrum of clinicohematological profile and its correlation with average parasite density in visceral leishmaniasis

CytoJournal ◽

10.4103/cytojournal.cytojournal_38_17 ◽

2018 ◽

Vol 15 ◽

pp. 19

Author(s):

Vijay Kumar ◽

Poojan Agarwal ◽

Sadhna Marwah ◽

A. S. Nigam ◽

Awantika Tiwari

Keyword(s):

Bone Marrow ◽

Visceral Leishmaniasis ◽

Parasite Density ◽

Plasma Cells ◽

Parasite Load ◽

Statistical Correlation ◽

Positive Trend ◽

Strong Negative Correlation ◽

Cell Percentage ◽

Bone Marrow Plasma

Background: Leishmaniasis is the prevalent in tropical and subtropical regions of the world. Demonstration of Leishman-Donovan (LD) bodies in the bone marrow aspirates (BMA) is vital to diagnosis of visceral leishmaniasis (VL). In the present study, we studied the clinicohematological parameters encountered in VL and correlated them with parasite load on BMA. Methods: Retrospective analysis over 3 years was done; clinical details, biochemical profile, complete hemogram with peripheral smear findings, and BMA smears were reviewed and average parasite density (APD) calculated in each case. Multivariate analysis and tests of significance were applied. Results: The study included 28 patients. Splenomegaly showed a positive trend with APD. rK39 antigen detection test was 100% positive in select cases. A strong negative correlation was observed between albumin to globulin ratio and grade of APD. BMA revealed hemophagocytosis (HPS) in 78.57% cases and it had a significant strong correlation with APD (P = 0.014). A significant correlation was also observed between APD and bone marrow plasma cell percentage (P = 0.01). LD bodies were noted in unusual locations such as within myelocytes (14.2%), plasma cells (7.1%), and megakaryocytes (10.7%). Conclusion: HPS and bone marrow plasmacytosis were two statistically significant findings, which showed positive correlation with parasite load. The presence of these two findings should prompt hematopathologists for more focused search of hemoparasites in BMA to arrive at a definitive diagnosis. This will avoid unnecessary workups and improve the prognosis. To the best of our knowledge, a statistical correlation between APD and clinicohematological parameters has never been previously studied.

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