A Histological Study of Renal Lesions of New Zealand Black Strain Mice

Abstract

Histological study was carried out on tisssue sections of 22 kidneys of New Zealand Black (NZB/Bl) strain mice which "spontaneous" lymphoid leukemia and autoimmune hemolytic anemia combined and also of 4 kidneys of normal control mice, aged one to three month-old. Renal lesions have been observed in section of kidneys of 17 out 22 adult mice (77%). No abnormal changes were fo und in all four normal control mice. Renal lesions consist of eosinophilic membranous thickening of glomerular capillary loops due to deposition of fibrin with PAS-positive material. The earliest histological changes was fibrinoid degeneration or hyaline thickening of capillary walls and adjacent intercapillary region of the glomeruli. Extention of this process, with dilatation of the hyaline degeneration produced narrowing of capillary lumens. In the later stages hyaline lobulation and conglomeration of the glomerular tuft soccurred. Reaction of Bowman's capsule is a mild in compare with glomerular changes. Tubular changes were not obvious until the glomerular damage is well in evidence. Tubular changes usually follows the glomerular changes. However there arecould be classified into three stages; earliest, advanced, later, by histological findings of combined glomerular and tubular changes. The "necrotising" arteritis developing in one case of later stage was seen. Perivascular tumor cell infiltrates were seen in 9 out 22 cases (40%). Tumor cell infiltrates presented along the course of the vessels as they extend towards the cortical region from hilar region. Renal lesions of the NZB mice are an exprimental model in the mouse for autoimmune disease, but it was unrelated to the infiltration by tumor cells. Glomerular changes are similar to those seen in human lupus nephropathy.