Pathomorphological and immunohistological changes in lymph nodes of cows spontaneously infected by bovine leukaemia
M Levkut1, L Plank, M Levkutova
1Department of Pathological Anatomy, University of Veterinary Medicine, Kosice, Slovakia.
Insights
Histologic examination of bovine leukaemia virus (BLV)-infected cow lymph nodes revealed various changes, including T-zonal hyperplasia. Eosinophilic infiltration and specific immunoglobulin lambda light chains were also noted in affected tissues.
Area of Science:
- Veterinary Pathology
- Immunology
- Virology
Background:
- Bovine leukaemia virus (BLV) causes persistent lymphocytosis in cattle.
- Lymph node alterations are key indicators of BLV infection.
- Understanding these changes aids in diagnosing and managing BLV.
Purpose of the Study:
- To histologically, cytochemically, and immunohistologically characterize lymph node changes in BLV-seropositive cows.
- To identify specific immunoglobulin light chain expression in affected cells.
- To correlate morphological findings with potential viral pathogenesis.
Main Methods:
- Histologic examination of prescapular lymph nodes from 109 BLV-seropositive cows.
- Cytochemical staining for acid phosphatase (AP).
- Immunohistologic examination for bovine immunoglobulin kappa or lambda light chains.
Main Results:
- Common findings included T-zonal hyperplasia (47.7%), B-zonal hyperplasia (21.1%), and mixed hyperplasia (16.5%).
- Eosinophilic infiltration was frequently observed.
- Immunohistochemistry detected only lambda Ig light chains in plasma cells and immunoblasts within pulp proliferation areas.
- Cytochemistry revealed a significant number of cells with diffuse positive AP reactions.
Conclusions:
- BLV infection induces diverse lymph node hyperplastic and atrophic changes.
- The presence of lambda Ig light chains suggests specific B-cell differentiation pathways.
- Acid phosphatase activity may indicate inflammatory or cellular activation processes in BLV-infected lymph nodes.
Abstract:
Prescapular lymph nodes from 109 cows seropositive to bovine leukaemia virus (BLV) were subjected to histologic, cytochemical and in dubious cases also to immunohistologic examination for the presence of light chains of bovine immunoglobulin (Ig) kappa or lambda. By their morphological features, the histologically detected changes were divided into B-zonal hyperplasia (23 cases, 21.1%), T-zonal hyperplasia (52 cases, 47.7%), pulp proliferation (6 cases, 5.5%), hyperplasia of mixed type (18 cases, 16.5%), and atrophy (10 cases, 9.2%). Some changes resembled those reported in infections with human or feline immunodeficiency virus. Eosinophilic infiltration was a frequent feature. Immunohistochemical examination revealed only a lambda Ig chain in the cytoplasm of plasma cells or plasmacytoid cells and immunoblasts in pulp proliferation. Cytochemical examination showed a considerable number of cells with a diffuse positive reaction to acid phosphatase (AP).
