Radiation nephritis

Introduction to radiation nephritis Radiation nephritis is a chronic interstitial nephritis that occurs after a large amount of radioactive irradiation, and the amount of radiation that causes the onset of the disease is often 2,500 rad (25 Gy) or more, and is a non-inflammatory chronic kidney disease. basic knowledge The proportion of illness: 0.001% Susceptible people: no special people Mode of infection: non-infectious Complications: uremia, malignant hypertension

Cause of radiation nephritis

(1) Causes of the disease

Tumors in the abdominal organs are not exposed to any radiation protection due to deep radiography. Generally, when the dose of the kidney is more than 2300R within 5 weeks (1R=2.58×10-4C/kg), Lead to the disease.

(two) pathogenesis

1. The pathogenesis of the acute phase is presumed to be related to vascular endothelial cell injury and necrosis caused by radiation exposure, ischemia, release of renin and angiotensin II-induced hypertension and disseminated intravascular coagulation.

2, the incidence of chronic radiation nephritis is similar to acute, but the lesion is mild, the ischemic process is slower; or it is derived from the unhealed period of the acute phase.

Radiation nephritis prevention

1. Protect the kidneys and carefully grasp and limit the radiation dose.

2. Isolation contact can reduce radiation damage.

Radiation nephritis complications Complications, uremia, malignant hypertension

The main complications of radiation nephritis are malignant hypertension, tubular necrosis, heart failure and uremia.

1, malignant hypertension: refers to a significant increase in blood pressure (common standard is diastolic blood pressure exceeds 140mmHg). And with a syndrome of vascular damage, vascular damage can be manifested as retinal hemorrhage, exudation and papilledema. Patients are prone to headache, irritability, dizziness, nausea, vomiting, palpitations, shortness of breath and blurred vision.

2, renal tubular necrosis: due to various causes of renal ischemia or nephrotoxicity caused by renal function, progressive decline and clinical syndrome. Mainly manifested as progressive azotemia caused by a significant decrease in glomerular filtration rate, as well as imbalance of water, electrolytes and acid-base balance caused by renal tubular reabsorption and excretion function. Urinary and non-oliguric.

3, heart failure: often caused by a variety of diseases, myocardial contractility is reduced, so that the blood output of the heart is reduced, insufficient to meet the needs of the body, and thus a series of symptoms and signs. Common symptoms include bloating, loss of appetite, nausea, vomiting, pain in the liver area, oliguria and difficulty breathing.

4, uremia: In fact, the human body can not produce urine through the kidneys, the waste produced by the metabolism of the body and excessive water excreted, the deterioration of the kidney with the disease caused by metabolic disorders caused by the poison. Uremia causes disorders in the nervous system, digestive system, cardiovascular system, respiratory system, and skin.

Radioactive nephritis symptoms common symptoms proteinuria type urinary fatigue nephrotic syndrome renal failure renal ischemic embolic nephritis renal artery stenosis

The severity of renal damage is positively correlated with the size of the dose. The smaller the dose received, the longer the incubation period, and the more often it is asymptomatic proteinuria or mild hypertension and renal dysfunction.

1. Acute radiation nephritis often shows obvious symptoms of nephritis 6 to 12 months after exposure to radiation. The cause is unknown. In the incubation period, mild proteinuria and hypertension may occur, and the onset is often rapid, and the patient has shortness of breath. Headache, loss of appetite, nausea, vomiting and extreme fatigue, followed by edema, moderate or severe hypertension, heart failure, anemia, proteinuria (most <2g / d, but even up to 4 ~ 5g / d), can There are tubular urine and microscopic hematuria, and progressive azotemia, the symptoms are similar to acute nephritis syndrome, but the onset of radiation nephritis is slower than acute nephritis, there is no red blood cell cast in the urine, the prognosis of acute radiation nephritis is bad, often Died of malignant hypertension and/or chronic renal failure, survivors often develop chronic radiation nephritis with a mortality rate of up to 50%.

2. Chronic radiation nephritis can be developed from acute radiation nephritis, or after receiving radioactive irradiation for several years or even 10 years, chronic radiation nephritis is found. There is no obvious history of acute radiation nephritis in the early stage, and its clinical manifestations are similar to chronic nephritis. For asymptomatic proteinuria, nephrotic syndrome may occur in some cases, renal function may be damaged to varying degrees, and hypertension may or may not occur. Chronic glomerulonephritis is a clinical manifestation of chronic glomerulonephritis. Urine, anemia, high blood pressure and slowly progressing uremia, salt loss can be the main manifestation, can be complicated by malignant hypertension at any time during the course of the disease, retroperitoneal cirrhosis can block one or both ureters and aggravate renal failure and loss Salt, can be accompanied by radiation enteritis, diarrhea can lead to the loss of protein and electrolytes.

3. High blood pressure after several years of exposure to radiation, unexplained high blood pressure, without renal failure, may be benign, or from the beginning is rapid and malignant hypertension, the cause may be only unilateral renal deficiency Blood-induced, rapid and malignant hypertension has a high mortality rate, mainly related to the severity of hypertension.

4. Simple proteinuria Some mild cases can only be simple proteinuria, and slowly develop to renal shrinkage and chronic progressive renal failure several years later.

Examination of radiation nephritis

1. Laboratory inspection:

(1) acute radiation nephritis can be seen anemia, proteinuria (most <2g / d, but can be as high as 4 ~ 5g / d); can have tubular urine and microscopic hematuria, and progressive azotemia. Generally there is no red blood cell cast in the urine.

(2) Chronic radiation nephritis often has simple proteinuria, salt-loss hypotonic urine, anemia; when the patient presents with chronic nephritis, mild to moderate proteinuria occurs, urine sediment has a small amount of red and white blood cells, occasionally particles Tube type. Poor concentration (polyuria), may have low blood sodium, hypokalemia and acidosis. The deterioration of renal dysfunction may have an increase in urea nitrogen and creatinine.

2, kidney biopsy:

(1) Acute radiation nephritis glomerular and tubule degeneration, interstitial edema and hemorrhage. Such as acute nephritis type, normal kidney size, glomerular basement membrane thickening, rupture, glassy change, vascular endothelial cell degeneration, intimal swelling, cellulose-like necrosis of renal artery and arteriolar wall after high-dose irradiation, thrombosis; Even in some cases, crescent formation is visible. Immunofluorescence was performed without immunoglobulin, complement or fibrinogen deposition, and the affected tissue was easily distinguished from normal tissues.

(2) Chronic radiation nephritis in chronic radiation nephritis, the kidney can be seen severe vascular sclerosis, glomerular shrinkage and mesangial sclerosis, tubule atrophy, interstitial fibrosis with mild inflammatory response, cystic fibrosis, sometimes visible malignancy Necrotic vascular disease of hypertension. Due to extensive necrosis of the arterial wall and thrombosis, glomerular sclerosis and tubular degeneration and necrosis are caused, eventually leading to renal atrophy. If only one side of the kidney receives radiation, the same lesion in the unilateral kidney may occur.

Diagnostic and differential diagnosis of radiation nephritis

Diagnostic criteria

According to clinical classification, laboratory examination and history of radiation exposure in the kidney area can make a diagnosis of this disease.

Acute radiation nephritis

(1) Incubation period: 6-12 months after receiving radiation, children can be shorter than 6 months.

(2) prodromal period: elevated blood pressure, anemia, enlarged heart, check for proteinuria.

(3) Clinical period: once symptoms appear, it rapidly develops into extreme fatigue, loss of appetite, edema, refractory anemia, high blood pressure; BUN, Scr is elevated in laboratory tests; moderately above protein can be tested after entering clinical stage Urine, hematuria is rare.

2. Chronic radiation nephritis

(1) Incubation period: It can be derived from the acute phase. Some patients can also develop symptoms after a few years of exposure to radioactivity.

(2) Clinical period: The main symptoms are anemia, hypertension, edema; laboratory tests for proteinuria, tubular urine, hypotonic urine and impaired renal function.

3. Simple (asymptomatic) patients with mild proteinuria have only mild asymptomatic proteinuria. Under normal circumstances, renal function can remain normal.

4. Benign hypertension is 2.5 to 5 years after radiation exposure, hypertension with varying degrees of proteinuria, and the prognosis is generally acceptable.

5. Malignant hypertension according to the time of its occurrence is divided into early malignant hypertension. If it occurs after 18 months of treatment, it is called advanced malignant hypertension, which is caused by radiation-induced renal artery stenosis.

Radiation nephritis should pay attention to the identification of diseases such as immune nephritis and amyloidosis caused by malignant tumors:

1, immune nephritis caused by malignant tumors: malignant tumors, relatively benign tumors. Tumor refers to a local mass formed by abnormal proliferation of local tissue cells under the action of various tumorigenic factors. Clinical manifestations of varying degrees of proteinuria, hematuria, tubular urine, edema, hypertension and varying degrees of renal dysfunction. The onset can be urgent, but most cases do not evolve from acute nephritis.

2, amyloidosis kidney damage: due to the accumulation of amyloid in the blood vessels of various organs and tissues in the body, can cause multiple organ damage, AL protein and AA protein invade the kidney has its own characteristics, the former often invade the capillary wall and Mesangial area, clinically characterized by nephrotic syndrome, the latter mainly invading the mesangial area, clinically often manifested as chronic renal failure.

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