Lymphoproliferative lesions in BB Wistar rats.

Area of Science:

• Immunology
• Pathology
• Endocrinology

Background:

• The BB Wistar rat is a key model for studying Type 1 diabetes.
• Altered immune function is implicated in the pathogenesis of diabetes.
• Lymphoproliferative disorders can be associated with immune dysregulation.

Purpose of the Study:

• To investigate the occurrence and morphology of lymphoproliferative lesions in diabetic BB Wistar rats.
• To examine lymph node abnormalities in both diabetic and nondiabetic BB Wistar rats.
• To assess the implications of these findings for immune alterations in this model.

Main Methods:

• Histopathological examination of abdominal lymphoid tissues and lymph nodes from diabetic and nondiabetic BB Wistar rats.
• Morphological classification of observed lesions, including B cell lymphoproliferative disorders and lymphomas.

Main Results:

• Fifteen percent of long-term diabetic BB Wistar rats developed abdominal B cell lymphoproliferative lesions.
• Lesions ranged from benign aggregates to malignant lymphomas (immunoblastic sarcoma, plasma-cell lymphoma).
• Both diabetic and nondiabetic rats exhibited variable, often extensive, lymph node replacement by plasmacytoid lymphocytes and plasma cells.

Conclusions:

• Diabetic BB Wistar rats exhibit a higher incidence of B cell lymphoproliferative lesions.
• Morphological abnormalities in lymph nodes are present in this model, irrespective of diabetic status.
• These findings provide further evidence of altered immunity in the BB Wistar rat model of diabetes.