New progress in diagnosis and treatment of IgA nephropathy

IgA nephropathy is a group of mesangial IgA deposition characterized by mesangial proliferative glomerulonephritis, in 1968 by the French pathologist Berger first reported the disease (the disease was known as Berger's disease). It is now widely accepted that the disease is the most common manifestation of primary glomerulonephritis worldwide. Although IgA nephropathy has been considered to be "recurrent and clinically benign hematuria" in the past, IgA nephropathy is now considered to be one of the leading causes of end-stage renal disease (25-40% development of renal failure), some of which Was malignant after.

IgA nephropathy is the most common glomerulonephritis in the world, the United States and Canada account for about 2-10% of renal biopsy, Europe and Australia about 20-25%, Japan is as high as 30% or more, China is estimated to account for primary renal 20-30% of glomerulonephritis. Data from Germany and France show that IgA nephropathy in the general population incidence of 0.02%, but scholars estimate that this is just the tip of the iceberg, Singapore data show that about 2.0%. IgA nephropathy can occur at any age, but is most common in people aged 11-30 years. The ratio of males to females ranges from less than 2: 1 in Japan to as much as 6: 1 in Northern Europe and the United States. Patients of different ages, their clinical manifestations have some differences. Although primary IgA nephropathy receives the most attention, many other diseases are clinically associated with IgA nephropathy.

Table 1 IgA nephropathy classification of the main reasons

IgA nephropathy allergic purpura

Secondary cause

Liver disease: alcoholic, primary biliary, cryptogenic cirrhosis, hepatitis B;

Intestinal diseases: celiac disease, chronic ulcerative colitis, Crohn's disease

Skin diseases: psoriasis, herpes-like dermatitis

Immune rheumatic diseases: rheumatoid arthritis, Sjogren's syndrome, ankylosing spondylitis, Behcet's disease, Reiter's syndrome, immune thrombocytopenia infection: HIV infection, toxoplasmosis, leprosy

Tumor: mycosis fungoides, lung cancer, mucous secretory cancer

Diseases associated with IgA nephropathy: ANCA-associated vasculitis, diabetic nephropathy, membranous nephropathy

First, the pathology

IgA nephropathy under light microscope the most typical change is focal or diffuse mesangial cell proliferation and mesangial matrix increased. Tubulointerstitial lesions with focal tubular atrophy, inflammatory cell infiltration and interstitial fibrosis more common. IgA nephropathy glomerular lesions of light microscopy performance can vary greatly, including almost all kinds of primary glomerulonephritis pathological manifestations. Glomerular lesions from normal or minor injury to a variety of proliferation and sclerosis can be seen. Proliferation and sclerosis can be focal or diffuse, segmental or global, and can be seen in the mesangial area as well as in capillary loops, with or without necrosis, small crescent or annular body.

Whether immunofluorescence or immunohistochemical methods can detect significant deposition of IgA and C3 in the mesangial area. Further typing can be used to determine the deposition of IgA1 or IgG and / or IgM, but the deposition of C1q and C4 is rare. Active IgA nephropathy IgA can also be seen along the capillary loop deposition. At the same time there are often fibrinogen in the mesangial area, capillary loop and crescent in vivo deposition. Small blood vessel wall can be rich in C3 particles deposition, especially in patients with hypertension.

Electron microscopy showed varying degrees of mesangial cell proliferation and expansion of the mesangial matrix, the common bulk of the electron dense material in the mesangial matrix, and sometimes subendothelial mass can also be seen under the electron dense deposition. Usually basement membrane width is normal, but some patients have local thickening of the basement membrane, fracture and plaque-like changes.

Second, clinical manifestations

Clinical manifestations of IgA nephropathy are diverse, many patients have no obvious symptoms and are not aware of any problems. May be only in conventional screening or other diseases when the suspect and about 20% of IgA nephropathy patients with severe azotemia treatment. However, there are some patients may be expressed as acute lesions. IgA nephropathy mainly include the following types, the incidence of the order of:

1. Repeated gross hematuria (30-40%)

1) occurs in the upper respiratory tract infection (gastrointestinal or urinary tract infection) after a few hours to 1-2 days

2) with no more symptoms, a small number of urinary discomfort, and was diagnosed with acute cystitis

3) gross hematuria Children and adolescents (80-90%) than adults (30-40%) more common

4) has nothing to do with the severity of the disease

5) Kidney pathology is generally Lee's classification II-III level

2. Occult nephritis type (20-30%)

1) microscopic hematuria, 25% with intermittent episodes of gross hematuria

2) with or without proteinuria (+)

3) a small number of high blood pressure

4) Kidney pathology is generally Lee's classification II-III level

3. Chronic nephritis type

1) microscopic hematuria, with or without proteinuria (+ - ++)

2) often high blood pressure

3) renal function may be decreased

4) Kidney pathology is generally Lee grade II-IV

4. A large number of proteinuria or nephrotic syndrome type

1) nephrotic syndrome, with or without microscopic hematuria

2) more than a high blood pressure.

3) some patients showed nephrotic syndrome, kidney light microscope can be: minimal change and mild diffuse proliferative glomerulonephritis.

4) Kidney pathology is generally Lee grade I-IV

5. Malignant hypertension

1) malignant hypertension

2) proteinuria (+ - ++), with or without microscopic hematuria

3) often associated with renal insufficiency 4) renal pathology generally Lee grade III-IV level

6. Progressive nephritis syndrome type:

1) progressive deterioration of renal function, there is progressive oliguria

2) proteinuria (+ - ++), with or without gross hematuria

3) more than a high blood pressure, anemia

4) renal pathology is generally crescentic nephritis, Lee's classification IV-V level