Table 2. Evaluation of the degree of severity of chronic glomerulopathies, in large populations of cats, based on several key points of morphological changes in glomeruli and the cortical layer of the kidney.

Type of morphological changes	Visual morphologic changes, light microscopy	Norma*		Mild degree *		Mean degree *		Severe degree*
I. Proliferation of cells in glomerule. 1) Intracapillary proliferation of mesangium. 2) Intracapillary proliferation and swelling endotheliocyte.	Hypercellularity and hypertrophy of glomrule	Number of changed glomeruli microscopic field during magnification power 40*	Number of cell nucleus entering into the composition of nodal part of glomerule	Number of changed glomeruli microscopic field during magnification power 40*	Number of cell nucleus entering into the composition of nodal part of glomerule	Number of changed glomeruli microscopic field during magnification power 40*	Number of cell nucleus entering into the composition of nodal part of glomerule	Number of changed glomeruli microscopic field during magnification power 40*	Number of cell nucleus entering into the composition of nodal part of glomerule
	Hypercellularity and hypertrophy of glomrule	no	45-75	1-3	80-100	2-7	110-140	All glomeuli are changed to some degree	More than 140
3) Extracapillary proliferation of epithelial cells of external layer of Bowman's capsule	Cellular and/or proteinaceous « demilunes» segmental or circular type and/or hyalinosis (with thickening) of glomerule capsule with obliteration of its lumen and compression of capillary loops.	Number of changed glomerule microscopic field during magnification power 40*		Number of changed glomerule microscopic field during magnification power 40*		Number of changed glomerule microscopic field during magnification power 40*		Number of changed glomerule microscopic field during magnification power 40*
		no		1-2		3-5		All glomeuli are changed to some extent
4) Segmentation of glomerule loops as a result of: а. Accumulation of membrane material and/or mesangium matrix. б. Increase of the number of mesangium cells.	1. “lobulation” of glomeule 2. “palmation” of glomerule	no		1-2		3-5		All glomeuli are changed to some degree
II. Infiltration of cortical layer by inflammatory cells.	Infiltration of cortical layer with agranulocytes: diffuse and/or focal (perivascular (around interstisial vessels), periglomerular and/or intraglomerular*).	Average number of agranulocytes in 4-5 microscopic field magnification power *40		Average number of agranulocytes in 4-5 microscopic field magnification power *40		Average number of agranulocytes in 4-5 microscopic field magnification power *40		Average number of agranulocytes in 4-5 microscopic field magnification power *40
		no		10-20		20-40		More than 50 (entirely)
III. Fibrinoid necrosis of capillary loops of glomerule with following fibrosis (sclerosis)of glomeruli.	Replacement of various structures of glomerule with connective tissue.	no		Number of changed glomerule microscopic field during magnification power 40*	Percentage of fibrinoid necrosis and/or replacement of various structures of glomerule with connective tissue	Number of changed glomerule microscopic field during magnification power 40*	Percentage of fibrinoid necrosis and/or replacement of various structures of glomerule with connective tissue	Number of changed glomerule microscopic field during magnification power 40*	Percentage of fibrinoid necrosis and/or replacement of various structures of glomerule with connective tissue
		no		2-4	from 20 to 40	5-7	from 40 to 70	More than 7
This classification can only be used for quantitative staging of the severity of glomerulopathies in the population of cats in general, but not for differentiation of glomerulopathies by morphological forms (e.g. minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), membranoproliferative glomerulonephritis and so on). *Histosection thickness is 3 – 4 microns. Focal agranulocytes infiltration around glomeruli. * Infiltration with agranulocytes of nodal part of the glomerule.