What Is Acute Glomerulonephritis?

Acute glomerulonephritis is a group of primary glomerulonephritis with acute nephritis syndrome as the main clinical manifestation. It is characterized by acute onset, hematuria, proteinuria, edema, and hypertension. It can be accompanied by transient azotemia and has a tendency to heal itself. It is common after streptococcal infection, but other bacterial, viral and parasitic infections can also be caused. The following describes acute glomerulonephritis after streptococcal infection. This disease is a self-limiting disease, and glucocorticoids and cytotoxic drugs should not be used.

Basic Information

English name

acute glomerulonephritis

Visiting department

Nephrology

Multiple groups

Children, men

Common causes

Often caused by -hemolytic streptococcus "nephritis-causing strain" infection

Common symptoms

Acute onset, hematuria, proteinuria, edema, and hypertension

Causes of Acute Glomerulonephritis

The disease is usually caused by -hemolytic streptococcus "nephritis-producing strains" (commonly group A type 12 and so on) infection, which is common after streptococcal infections such as upper respiratory infection, scarlet fever, and skin infection. The severity of the infection is not exactly consistent with the occurrence and severity of acute nephritis. The disease is mainly caused by the immune response induced by the infection.

Clinical manifestations of acute glomerulonephritis

Acute nephritis is more common in children and men. Onset usually occurs 1 to 3 weeks after the precursor infection. The incubation period is equivalent to the time required to induce the immune complex to be produced after the primary immunization of the pathogenic antigen. The incubation period for patients with respiratory infection is shorter than that for skin infection. The onset of this disease is more acute, and the severity of the disease is different. The mild cases are subclinical (only urinary abnormalities are typical); the typical ones are manifested as acute nephritis syndrome, and the severe cases may have acute renal failure. Most of the disease has a good prognosis, and often can heal clinically within months.

The typical person with this disease has the following manifestations:

1. Hematuria and proteinuria

Almost all patients have glomerular hematuria, and about 30% of patients may have gross hematuria, which is often the first symptom of the onset and the cause of the patient's treatment. May be accompanied by mild to moderate proteinuria, about 20% of patients with proteinuria in the range of nephrotic syndrome. In addition to erythrocytes, urinary sediment can be seen in the early stages of increased white blood cells and epithelial cells, and can have granular casts and red blood cell casts.

Edema

Edema is often the initial manifestation of the onset, and is typically manifested as eyelid edema in the morning or mild depression edema in the lower extremities. A few severe cases can affect the entire body.

3. Hypertension

Most patients develop transient mild to moderate hypertension, often associated with water and sodium retention. Blood pressure may gradually return to normal after diuretic treatment. A few patients can develop severe hypertension, or even hypertensive encephalopathy.

4. Renal dysfunction

In the early stage of onset, the urine output decreased due to the decreased glomerular filtration rate and water and sodium retention. A few patients even had oliguria (<400ml / d). Renal function can be transiently impaired and manifested as mild azotemia. Urine volume gradually increased after more than 1 to 2 weeks, and renal function gradually returned to normal within a few days after diuresis. Only a few patients can present with acute renal failure and need to be distinguished from aggressive nephritis.

5. Congestive heart failure

It often occurs in the acute phase. Serious retention of water and sodium and hypertension are important inducements and need urgent treatment.

6. Immunological examination abnormal

Transient serum complement C3 decreased: more than 2 weeks after the onset of decline, and gradually returned to normal within 8 weeks, which is of great significance for the diagnosis of this disease. Patients' serum anti-streptolysin "O" titers may increase.

Pathology of acute glomerulonephritis

For capillary proliferative glomerulonephritis. It is characterized by diffuse proliferation of endothelial and mesangial cells under light microscope and infiltration of neutrophils; immunofluorescence shows that IgG and C3 are coarse particles deposited along the capillary wall and mesangial area; electron microscopy shows hump under glomerular epithelial cells Large-scale electron dense deposits.

Diagnosis of acute glomerulonephritis

The disease can be diagnosed clinically based on 1 to 3 weeks after streptococcal infection, manifestations of nephritis syndrome, and transient serum C3 decline. If the glomerular filtration rate decreases progressively or the condition does not show a general improvement within 2 months, a renal biopsy should be performed in time to confirm the diagnosis.

Differential diagnosis of acute glomerulonephritis

1. Glomerular disease with acute nephritis syndrome

(1) Acute nephritis after infection with other pathogens Many bacterial, viral and parasitic infections can cause acute nephritis. Most of the clinical manifestations of acute nephritis after viral infection are mild, often without reduced serum complement, rarely edema and hypertension, renal function is generally normal, and the clinical process is self-limited.

(2) In addition to clinical manifestations of acute nephritis syndrome, mesangial capillary glomerulonephritis is often accompanied by nephrotic syndrome, and the lesions often persist. 50% to 70% of patients have persistent hypocomplementemia and do not recover within 8 weeks.

(3) Some patients with mesangial proliferative glomerulonephritis (IgA nephropathy and non-IgA mesangial proliferative glomerulonephritis) may have an acute nephritis syndrome with precursor infection. The serum C3 of the patient is generally normal, and the condition is not self-healing. IgA nephropathy patients have a short incubation period, and gross hematuria may occur within hours to days after infection. Hematuria may recur, and serum IgA may increase in some patients.

2. Progressive glomerulonephritis

Onset is similar to acute nephritis, but with progressive deterioration of renal function. When severe acute nephritis presents with acute renal failure and it is difficult to distinguish the disease, a renal biopsy should be performed in time to make clear.

3. Systemic systemic kidney involvement

Lupus nephritis, allergic purpuric nephritis, bacterial endocarditis kidney damage, primary cryoglobulinemia kidney damage, vasculitis kidney damage, etc. can present acute nephritis syndrome; according to the typical clinical manifestations of other system involvement And laboratory inspections can be identified.

Acute glomerulonephritis treatment

The treatment of this disease is mainly rest and symptomatic treatment. Patients with acute renal failure should be dialyzed and wait for their natural recovery. This disease is a self-limiting disease, and glucocorticoids and cytotoxic drugs should not be used.

General treatment

The acute phase should rest in bed, and gradually increase the amount of activity after the gross hematuria disappears, the edema subsides, and the blood pressure returns to normal. The acute phase should be given a low-salt (under 3g daily) diet. People with normal renal function do not need to limit the amount of protein, but protein intake should be limited during azotemia, and high-quality animal protein is the main factor. Patients with acute renal failure with significant oliguria need to limit fluid intake.

2. Treat the infection

If the infection is present, treat it accordingly.

3. Symptomatic treatment

Including diuretic swelling, lowering blood pressure, prevention of cardio-cerebral comorbidities. Antihypertensive drugs can be added when restless, low salt and diuretic control is still not satisfactory.

4. Dialysis treatment

In a few cases of acute renal failure with indications for dialysis, timely dialysis treatment should be used to help patients through the acute phase.