Overview of Cholesterol Crystals Embolic Nephropathy
Cholesterol crystal embolic nephropathy, also known as atherosclerotic embolic nephropathy, is a renal vascular disease caused by the rupture of atherosclerotic plaques on the walls of the aorta or renal arteries, which releases cholesterol crystals and embolizes the small renal arteries. The disease mostly triggers acute or subacute renal injury, with clinical manifestations such as fever, myalgia, loss of appetite, peripheral blood eosinophilia, and urinary abnormalities.
Causes
Atherosclerosis is the basis of this disease. Atherosclerotic plaques in the aorta or renal arteries may rupture spontaneously, but more often rupture occurs under the influence of medical causative factors, such as action vein angiography, arterial vascular surgery, arterial vascular intervention, anticoagulant therapy and thrombolytic therapy.
Symptoms
The severity of clinical manifestations depends on the extent of cholesterol crystal embolization.
1. Spontaneous rupture of atherosclerotic plaque leading to renal embolism
The scope is small, and the clinical symptoms are often asymptomatic.
2. Embolism induced by medical factors
A wide range of clinical symptoms of renal embolism, often accompanied by other organ system embolism: ① acute or subacute renal injury: the former occurs suddenly within 1 week after the triggering event, and the latter progresses gradually over a period of several weeks; ② systemic symptoms: fever, myalgia, loss of appetite, emaciation, etc.; ③ high blood pressure in about half of the patients, and sometimes it is difficult to control; ④ other organ system embolism: the most common is skin embolism, followed by the skin embolism, the most common is skin embolism. Embolism in other organ systems: the most common is skin embolism, followed by gastrointestinal embolism.
Examination
1. Laboratory examination
Acute stage patients can see peripheral blood eosinophilia. Half of the patients may have urine abnormalities, the examination can see a small amount of proteinuria, mild microscopic hematuria, eosinophilic granulocyturia and tubular urine.
2. Histopathological examination
(1) The void left after the dissolution of cholesterol crystals in the small arteries can be seen, which is manifested as a narrow, long, pointed at both ends and a convex pike-shaped void at the waist. Renal puncture biopsy tissue sampling is limited and the positive rate is low, while skin embolization sampling has a high positive rate.
(2) Renal histopathology sometimes shows ischemia-induced acute tubular necrosis, and glomerular ischemic crumpling and sclerosis, renal interstitial inflammatory cell infiltration and fibrosis.
Diagnosis
(1) It occurs in middle-aged and elderly people with a history of atherosclerosis.
(2) There are often obvious triggers before the onset of the disease, such as vascular surgery of the aorta or renal artery, vascular intervention, anticoagulant therapy, and so on.
(3) Renal damage is mostly acute or subacute, often appearing days, weeks or months after the triggering event. With or without urinary abnormalities, peripheral blood eosinophilia and hypertension.
(4) Manifestations of skin embolism, gastrointestinal embolism, and other organ system embolisms.
(5) Histopathological examination shows the voids left by the dissolution of cholesterol crystals in the small arteries of renal tissue.
Of the above five points, histopathologic examination is the “gold standard” for diagnosis of this disease, but it is not suitable for renal puncture biopsy, with the first four typical manifestations, can also be diagnosed.
Differential diagnosis
Cholesterol crystal embolic nephropathy caused by angiography or treatment needs to be differentiated from contrast nephropathy caused by iodine contrast agent. The former often develops days, weeks or months after the interventional examination or treatment, and the renal impairment progresses gradually and remains unremitting after the onset of the disease. In the latter case, the onset of acute kidney injury often occurs within 2-3d after intervention or treatment, and the injury often recovers within 2-3 weeks, and there is no extra-renal organ system embolization in contrast nephropathy.
Treatment
1. Treatment of crystalline embolism
Commonly used drugs are statins, glucocorticoid drugs, antiplatelet drugs and anticoagulants. Statins can play a role by stabilizing atherosclerotic plaques, lowering blood lipids and antagonizing inflammation. Glucocorticoid drugs can be used to control the acute inflammatory response.
2. Treatment of hypertension
Antihypertensive drug treatment should be given, and the combined application of multiple drugs is more effective.
3. Treatment of renal failure
If there are symptoms of renal failure and the indication of dialysis is reached, dialysis treatment should be carried out in time. Peritoneal dialysis and hemodialysis can be used, and the dosage of anticoagulant should be minimized in hemodialysis.
Prevention
For middle-aged and elderly patients with a history of atherosclerosis, arterial angiography, arterial vascular surgery, arterial vascular intervention, anticoagulant therapy and thrombolytic therapy should be carefully selected.