What is acute glomerulonephritis? What are its symptoms?

Due to the accelerated pace of life, more and more people are dealing with kidney disease. Acute glomerulonephritis is also a relatively common type. So what are the causes of this disease?

1. Introduction to the cause

The disease is often caused by infection with "nephritis-causing strains" of hemolytic streptococci, and is common after streptococcal infections such as upper respiratory tract infections (mostly tonsillitis), scarlet fever, and skin infections (mostly impetigo).

Bacterial infections can also cause disease, including bacteremia, various viral and parasitic diseases, Pneumococcus, Staphylococcus aureus and epidermidis, Klebsiella pneumoniae, meningococci, Salmonella typhi, etc.

2. Clinical manifestations

The disease has an acute onset and the severity varies. Mild cases are subclinical (only urine routine and serum C3 are abnormal); typical cases present with acute nephritic syndrome, and severe cases may develop acute renal failure.

The disease typically presents with the following symptoms:

1. Abnormal urine

Almost all patients have glomerular hematuria, and some patients may have macroscopic hematuria, which is often the first symptom of the disease and the reason for patients to seek medical treatment.

2. Edema

Most patients have edema, which is often the initial manifestation of the disease. Typical manifestations are eyelid edema in the morning or mild pitting edema in the lower limbs. In a few severe cases, the disease may spread to the whole body.

3. Hypertension

Most patients experience transient mild to moderate hypertension, which is often related to sodium and water retention. Blood pressure can gradually return to normal after diuresis. A small number of patients may develop severe hypertension or even hypertensive encephalopathy.

4. Abnormal renal function

In the early stage of the disease, the patient's urine volume decreases (usually between 400 and 700 ml/d), and a few patients even have oliguria (<400 ml/d). Renal function may be transiently impaired, manifesting as mild azotemia. After more than 1 to 2 weeks, the urine volume gradually increases, and renal function can gradually return to normal within a few days after diuresis. Only a very small number of patients may present with acute renal failure.

5. Congestive heart failure

It often occurs during the acute nephritic syndrome period, and patients may have symptoms of jugular vein distension, gallop rhythm, and pulmonary edema.

3. Disease diagnosis

The diagnosis is based on clinical manifestations and relevant examinations.

It should be differentiated from acute nephritis after infection with other pathogens, mesangial capillary glomerulonephritis, mesangial proliferative glomerulonephritis (IgA nephropathy and non-IgA mesangial proliferative glomerulonephritis), rapidly progressive glomerulonephritis,

Differentiate between systemic lupus erythematosus nephritis, Henoch-Schonlein purpura nephritis, bacterial endocarditis renal damage, essential cryoglobulinemia renal damage, vasculitis renal damage and other diseases.

4. Complications

Serum C3 and total complement decrease in the early stage of the disease and gradually return to normal within 8 weeks, which is of great significance for the diagnosis of the disease. The patient's serum antistreptolysin "O" titer may be elevated, suggesting a recent streptococcal infection. In addition, some patients may test positive for circulating immune complexes and serum cryoglobulins in the early stages of the disease.

When clinical diagnosis is difficult, patients with acute nephritic syndrome should consider undergoing renal biopsy to confirm the diagnosis and guide treatment. The indications for renal biopsy are: ① patients with oliguria for more than one week or progressive decrease in urine volume accompanied by worsening renal function; ② patients with a disease course of more than two months without a trend of improvement; ③ patients with acute nephritic syndrome and nephrotic syndrome.