Components to renal score:
(1) activity index
(2) chronicity index
Each histologic feature is graded according to the following table.
|
Finding
|
Points
|
|
none
|
0
|
|
mild
|
1
|
|
moderate
|
2
|
|
severe
|
3
|
after Table 1, page 783
Activity index
Glomerular abnormalities:
(1) cellular proliferation
(2) fibrinoid necrosis and/or karyorrhexis
(3) cellular crescents
(4) hyaline thrombi and/or wire loops
(5) leukocyte infiltration
Tubulointerstitial abnormalities:
(1) mononuclear-cell infiltrate
activity index =
= (points for cellular proliferation) + (2 * (points for fibrinoid necrosis or karyorrhexis)) + (2 * (points for cellular crescents)) + (points for hyaline thrombi or wire loops) + (points for leukocyte infiltration) + (points for mononuclear cell infiltrate)
Chronicity index
Glomerular abnormalities:
(1) glomerular sclerosis
(2) fibrous crescents
Tubulointerstitial abnormalities:
(1) interstitial fibrosis
(2) tubular atrophy
chronicity index =
= (points for glomerular sclerosis) + (points for fibrous crescents) + (points for interstitial fibrosis) + (points for tubular atrophy)
The authors described a new variable called the tubulointerstitial index based on the severity of the interstitial fibrosis and tubular atrophy.
|
Tubulointerstitial Findings from Chronicity Index
|
Tubulo-Interstitial Index
|
|
BOTH interstitial fibrosis AND tubular atrophy absent (both 0)
|
0
|
|
EITHER interstitial fibrosis OR tubular atrophy >= 1
|
1
|
|
BOTH interstitial fibrosis AND tubular atrophy >= 1
|
2
|
Interpretation:
• minimum score: 0
• maximum activity index: 24
• maximum chronicity index: 12
• The higher the score, the more severe the nephritis.
