The pathogenesis of IgAN is not well understood, and the disease should not be treated as a unique disease, but rather as a group of clinical syndromes with the same renal immunopathological features.
I. Clinical typing and treatment of IgA nephropathy?
II. Pathological typing of IgA nephropathy
Pathological typing of IgA nephropathy I.
In 1982, WHO officially changed the renal pathological staging of IgA nephropathy into five grades.
Grade I :Minor damage.
Grade II : microscopic lesions with a small amount of segmental tegument proliferation.
Grade III : focal segmental glomerulonephritis with less than 50% of the glomeruli showing significant changes.
Grade IV: diffuse tegmental damage with proliferation and sclerosis; Grade V: diffuse sclerosing glomerulonephritis involving more than 80% of the glomeruli.
Laboratory tests: In 50% of cases, blood IgA levels are elevated, while blood complement concentrations are mostly normal. IgA circulating immune complexes are elevated in the blood in 10-15% of patients. Skin biopsies of the palmar forearm often show capillary deposits of IgA, C3 and fibrin. Urine erythrocyte morphology is dominated by aberrant erythrocytes (≥80%).
Pathological typing of IgA nephropathy II.
lee classification system
IgA nephropathy pathology classification
Ⅰ overwhelmingly normal, occasionally mild thylakoid widening (segmental); no with/without cellular hyperplasia no.
II Focal glomerular thylakoid proliferation and sclerosis (<50%); none Rare small crescentic bodies none.
iIII Diffuse thylakoid proliferation and widening (occasional focal segments); occasional small crescents and adherent focal interstitial edema, occasional cellular infiltration, rare tubular atrophy.
i IV Severe diffuse thylakoid proliferation and sclerosis with partial or complete glomerulosclerosis; tubular atrophy with crescent bodies (45%), interstitial infiltration, and occasional interstitial foam cells are seen.
V Lesions similar in nature to grade IV but more severe; glomerular crescent formation >45% similar to grade IV lesions but more severe.
Haas classification system
I (mild lesions) Glomeruli with only mild increase in thylakoid cells; no segmental sclerosis, no crescent body no lesions.
i II (FSGS-like lesion) Glomeruli showing similar idiopathic FSGS-like changes,; with mild increase in glomerular thylakoid cells; no crescentic body without lesions.
III (focal proliferative glomerulonephritis) Glomerular cell proliferation in about 50% of glomeruli; cell proliferation may initially be limited to the thylakoid region or may be due to capillary. Intravascular cell proliferation causes obstruction of glomerular capillary collaterals. Crescent bodies may be seen. The vast majority of type III lesions show glomerular segmental cell proliferation (some patients may have no such lesion) without lesions.
Type IV (diffuse proliferative glomerulonephritis) >50% of the glomeruli are proliferating, either segmentally or globularly, as in type III lesions, and the crescent is seen without lesions.
I V (advanced chronic glomerulonephritis) more than 40% of glomerulosclerosis can be manifested by cortical tubular atrophy or reduced tubular number (PAS) in >40% of the above glomerular lesions.
Oxford Staging System (MEST)
Katafuchi score criteria for IgA nephropathy:
Glomerular score (1-12 points)
Glomerular cell proliferation degree score
The mean value of all glomerular scores was divided into 1 to 4 points: 1 point:1≤mean value <2
2 points:2≤mean value＜3 3 points:3 mean value＜4 4 points:mean value = 4
[Mean value = sum of all individual glomerular scores/number of glomeruli]
[Individual glomerular score: The score according to the ratio of the cellular political area to the total glomerular area is (1-4 points).
1, None; 2, Mild (<25%); 3, Moderate (25%-50%); 4, Severe (>50%)]
Segmental damage score
The percentage of crescentic bodies, adhesions and segmental sclerosis were scored as 0 to 4: 0 points:none
1 point:<10% 2 points:10%-25% 3 points:25%-50% 4 points:<50%
Spherical sclerosis score
The percentage of glomeruli with spherical sclerosis in the total number of glomeruli is divided into 0-4 points: 0 points: none 1 point: <10% 2 points: 10%-25% 3 points: 25%-50% 4 points: <50%
Katafuchi score: tubulo-interstitial score
Calculated as the percentage of cortical renal tissue area occupied by the lesion
0 points:None 1 points:<25% 2 points:25%-50% 3 points:<50%
Interstitial inflammatory cell infiltration (0-3 points)
Interstitial fibrosis (0-3 points)
Renal tubular atrophy (0-3 points)
Katafuchi score/vessel score
Vascular wall thickening (0-3 points)
Vessel wall thickening: vessel ID/OD in cross-section ≤ 0.5
Calculated as the percentage of diseased vessels
0 points:None 1 points:<10% 2 points: 10%-25% 3 points: <25%
Hyaline-like degeneration (0-3 points)
0 points: none 1 point: <25% 2 points: 25%-50% 3 points: <50%
III. Clinicopathological typing
According to the clinical symptoms of IgA nephropathy, the pathological typing of IgA nephropathy mainly includes the following types.
1, asymptomatic microscopic hematuria type pathological examination is normal or slightly changed (grade I-II ) IgA nephropathy, can be treated by traditional Chinese medicine alone.
2.Recurrent botrythematous hematuria type With upper respiratory tract infection or intestinal infection should be treated with strong Chinese medicine in time. After the disappearance of sarcoid hematuria, continue to apply traditional Chinese medicine treatment, and can perform tonsil removal.
3.Nephrotic syndrome type.
4.Nephritis syndrome type Treatment should focus on controlling blood pressure, maintaining kidney function and delaying the deterioration of kidney function, and can also be treated with traditional Chinese medicine.
5, IgA nephropathy pathology other types of fractionation such as acute progressive nephrotic syndrome, acute renal failure. It is less common clinically and has a poor prognosis.
The pathological typing of IgA nephropathy is different, and the diagnostic results of renal biopsy are different, so the treatment of IgA nephropathy is also different. Therefore, after getting the laboratory results, patients with IgA nephropathy should first understand the pathological type they belong to, and then make the corresponding diagnosis and treatment according to its characteristics and severity.
Mr. Nan suggested that, as the pathogenesis of IgAN is not well understood, the disease should not be treated as a unique disease, but rather as a group of clinical syndromes with the same renal immunopathological features.
For this reason, a “clinicopathologic typing” has been proposed and the treatment plan is based on this typing