Takayasu arteritis in children

Introduction to Pediatric Arteritis Aortitis is a chronic progressive non-specific inflammation of the aorta and its main branches and pulmonary arteries, which causes stenosis or occlusion in different parts. A small number of patients cause arterial dilatation or aneurysms due to inflammation destroying the middle layer of the arterial wall. The clinical manifestations vary depending on the location of the lesion. basic knowledge Sickness ratio: 0.001%-0.002% Susceptible people: children Mode of infection: non-infectious Complications: pulmonary hypertension angina pectoris myocardial infarction aortic valve insufficiency

Causes of pediatric arteritis

Cause:

The cause is still unclear, there have been syphilis, arteriosclerosis, tuberculosis, thromboangiitis obliterans (Buerge disease), congenital anomalies, giant cell arteritis, connective tissue disease, rheumatism, rheumatoid disease, endocrine abnormalities, metabolism Abnormalities are related to factors such as autoimmunity.

Autoimmune factors (20%):

At present, it is generally believed that this disease may be caused by the in vivo immune process after infection by streptococcus, tuberculosis, virus or rickettsia. Its performance characteristics: 1 blood 2 serum protein electrophoresis commonly has 7 kinds of globulin, a1 and 2 globulin Increased; 3 "C" reactive protein, anti-chain "O" and anti-mucopolysaccharidase abnormalities; 4 collagen disease and the disease combined; 5 aortic arch syndrome and rheumatoid rheumatoid aortitis similar; 6 hormone therapy Obvious curative effect, but these characteristics are not reliable evidence of immunology of the disease. The titer and antibody price of serum anti-aortic antibody are significantly higher than other diseases. The aortic antigen is located in the middle and outer membrane of the aorta, and the serum immunoglobulin The protein showed that IgG, IgA and IgM were both increased, and the latter two were characterized by autopsy. Some autopsy found active tuberculosis in some patients, including tuberculosis of the periorbital lymph nodes. Shimizt et al believe that the lesion may be directly affected by this disease. Aortic or an allergic reaction to tuberculous lesions. Microscopic examination revealed a new granuloma and Laghans giant cells in the arterial wall of the lesion. It is a non-specific inflammation, no tuberculosis is found, and tuberculosis rarely invades the vascular system. From clinical observations, about 22% of patients have tuberculosis, mainly cervical and mediastinal lymphatic tuberculosis or tuberculosis, with various anti-tuberculosis drugs. Treatment, ineffective for aortitis, indicating that the disease is not directly caused by tuberculosis infection.

Endocrine abnormalities (20%):

The disease is more common in young women, so it is thought that it may be related to endocrine factors. Numano et al observed the female nasal arteritis in the follicular and luteal phase 24h urine specimens, found that the excretion of estrogen was significantly higher than that of healthy women, in the rabbit test, long-term The application of estrogen can produce pathological changes similar to aortitis in the aorta and its main branches. Clinically, high doses of estrogen can easily damage the blood vessel wall. For example, patients taking prostate cancer can cause vascular disease and stroke. Increased, long-term use of contraceptives can cause complications of thrombosis, so Numano and other believe that excessive secretion of estrogen and malnutrition factors (tuberculosis) may be the cause of high incidence of this disease.

Genetic factors (20%):

In recent years, the relationship between aortitis and heredity has attracted the attention of some scholars. Numano has reported that 10 pairs of close relatives, such as sisters, mothers and daughters, have been found in Japan, especially in twin sisters. For homozygotes, a pair of twin sisters have been found to have arteritis in China, and two pairs of non-biological sisters are clinically consistent with the diagnosis of aortitis, but only 1 of each pair has angiography, and we have 67 cases. HLA analysis of patients with arteritis found that A9, A10, A25, Awl9, A30, B5, B27, 1340, B51, Bw60, DR7, DRw10, DQtw3 appeared frequently and statistically significant, but the antigen was not concentrated enough. HLA analysis of patients with arteritis found that A9, A10, B5, Bw40, Bw51, Bw52 appeared frequently, especially Bw52, and 124 patients were followed up for 20 years. Bw52-positive arteritis was severely inflammatory and required hormones. The dose is large and resistant to hormones; the complications of aortic regurgitation, angina pectoris and heart failure are more serious than those of Bw52 negative, suggesting that HLA antigen gene imbalance has an important role.

Recent studies have found that Chinese Han arteritis patients are significantly associated with HLA-13R4 and DR7 alleles. The nucleotide variation of the upstream regulatory region of the DR7 allele may be related to its pathogenesis and disease, and it is found that DR4(+) or DR7 ( +) Patients with lesions and arterial stenosis were more severe than those with DR4(-) or DR7(-). Kitamura reported HLA-1352(+) vs. 1352(-), aortic regurgitation, ischemic heart Disease, lung infarction, etc. were significantly higher, and the incidence of renal artery stenosis, B39 (+) was significantly higher than 1339 (-).

Arteritis mainly involves the elastic arteries, such as the aorta and its main branches, pulmonary artery and coronary artery. This disease also often involves the muscular arteries. About 84% of the patients have 2 to 13 arteries, including the brachiocephalic artery. The left subclavian artery, the renal artery, the abdominal aorta and the superior mesenteric artery are the most common sites, the abdominal aorta is associated with renal artery involvement in about 80%, and the simple renal artery involvement is 20%, unilateral and bilateral involvement. Similarly, the celiac artery and the radial artery; pulmonary artery involvement accounted for about 50%; coronary artery involvement was not uncommon in recent years.

Pathological change

(1) Morphological changes: This disease begins from the middle layer of the arteries and the outer membrane to the full-thickness of the arterial wall of the intima, showing diffuse intimal fibrous tissue hyperplasia, showing extensive and irregular hyperplasia and hardening, and the lumen has Different degrees of stenosis or occlusion, often combined with thrombosis, the lesion is more severe at the entrance of the aortic branch, the disease is often multiple, the normal tissue area is often seen between the two affected areas, showing a jumping lesion (skip lesion As the lesion progresses, the normal tissue area gradually decreases. In elderly patients, there is often atherosclerosis. In recent years, it has been found that the incidence of arterial dilatation lesions caused by this disease is higher than before, because the lesion progresses rapidly. The elastic fibers and smooth muscle fibers of the arterial wall are severely damaged or broken, while the fibrosis is delayed and insufficient, and the arterial wall is thinned. Under the influence of local hemodynamics, the artery is dilated or aneurysm is formed, which is more common in the thoracic and abdominal aorta. And the right brachiocephalic artery, more common in men, Hotchi had found in 47 autopsy in 47 cases (57.3%) with arterial dilatation, aneurysm and arterial dissection, of which arterial dilation 26 (31.7%), aneurysm in 11 cases (13.4%), aneurysm with arterial dilatation in 6 cases (7.3%), arterial dissection in 4 cases (4.9)%, pulmonary artery lesions and aorta were basically the same, the main lesions in the middle and outer Membrane, intimal fibrous thickening is a secondary reaction of the medial and adventitial inflammation, almost obstructive lesions can be seen in the branches around the pulmonary artery, and the bronchial artery forms a collateral anastomosis. After bilateral elastic and muscular arteries are involved. Pulmonary hypertension can be suggested.

(2) Histological changes: Nasu divides the pathology of aortitis into three types, namely granulomatous type, diffuse inflammatory type, and fibrotic type, of which fibrosis type is dominant, and there is a gradual increase trend, even in fibrosis type. In the middle, near the old lesions, new active lesions can be seen. It is difficult to determine the initial inflammation of the disease during autopsy. According to the study, there are three different manifestations of inflammation, namely acute exudation, chronic non-specific inflammation and granuloma. The affected area is gradually enlarged, and the middle layer of the artery is often scattered, and there may be inflammation granulation tissue and coagulative necrosis. The middle and outer membranes of the nourishing blood vessels in the outer membrane are obviously thickened, causing stenosis or occlusion of the lumen; Lymphocytes and plasma cells were infiltrated in all layers, and epithelioid cells and Langham giant cells were also seen in the middle layer. Electron microscopy showed that the smooth muscle cells of the arterial wall were slender, mostly filled with myofilaments, and few organelles; Destruction, decomposition and disappearance of myofilament, swelling of mitochondria and endoplasmic reticulum, vacuolization, resulting in emptying and disintegration of cells; irregular nuclei, peripheral agglutination of chromatin, rare fibroblasts, collagen fibrils Rich, partially dissolved, less reticular fibers, elastic fibers have a uniform distribution, silky fibers of low electron density matrix, as well as of loose longitudinal traveling.

Pediatric arteritis prevention

To prevent possible incentives, the room should not be too cold and humid, the temperature should be appropriate, prevent infection, strengthen exercise, enhance physical fitness, improve autoimmune function, regular life, strengthen nutrition, not cold drink and over-eating fat, Do not eat spicy food and avoid alcohol and tobacco.

Pediatric arteritis complications Complications pulmonary hypertension angina pectoris myocardial infarction aortic regurgitation

Carotid and vertebral artery stenosis and occlusion can cause visual field reduction or even blindness. Pulmonary hypertension is mostly a late complication. Coronary artery stenosis causes angina or myocardial infarction, and aortic regurgitation (moderate or higher) causes the heart. Significantly expanded, heart function decreased.

Pediatric arteritis symptoms Common symptoms Nasal persistent fever, dizziness, no pulse, shortness, night sweats, cerebral ischemia, vascular murmur, weight loss, heart palpitations

A few weeks before the onset of local symptoms or signs, the child may have systemic symptoms such as fever, night sweats, weight loss, anorexia, etc. When local symptoms or signs appear, systemic symptoms may gradually reduce or disappear, according to the lesions are divided into 4 types: Type I involves the aortic arch, type II is predominantly thoracic aorta and abdominal aorta, type III is diffuse aortic lesion (wide type), type IV is diffuse aorta and pulmonary artery damage (pulmonary type).

1. Type I: mainly involving the aortic arch and its branches, also known as the brachiocephalic arterial type, cerebral ischemia caused by dizziness, headache, dizziness, severe recurrent syncope, convulsions, aphasia, hemiplegia or coma, upper limb ischemia caused limb weakness , numbness, chills, soreness, and even muscle atrophy, affected arterial pulsation weakened or disappeared, audible systolic murmurs, and occasional continuous vascular murmurs caused by collateral circulation.

2. Type II: Also known as the main-renal artery type, this type of child is common, with high blood pressure when complaining of headache, shortness of breath, palpitations; limb weakness, cold, soreness; may have intermittent claudication, severe heart failure, Can be misdiagnosed as myocardial lesions, physical examination found that blood pressure increased, femoral artery, dorsal artery pulsation weakened or disappeared.

3. Type III: The lesions are extensive, the parts are multiple, and the condition is more serious.

4. Type IV: palpitations, shortness of breath, and systolic murmur in the auscultation area of the pulmonary valve, P2 hyperthyroidism.

Examination of pediatric arteritis

1. Erythrocyte sedimentation rate increases: ESR is an important indicator reflecting the pathological activity of this disease. About 43% of patients have fast erythrocyte sedimentation rate, which can reach as fast as 130mm/h, among which within 10 years of onset, most of the ESR increases faster than 10 In the year, the condition of the patient tends to be stable, and the erythrocyte sedimentation rate returns to normal.

2. "C" reactive protein: its clinical significance is the same as erythrocyte sedimentation rate, and the positive rate is similar to erythrocyte sedimentation rate, which is an indicator of the disease activity of this disease.

3. Anti-streptolysin "O": The increase of such antibodies only indicates that the patient has had a hemolytic streptococcal infection recently, and about half of the patients have a positive or suspected positive reaction.

4. Blood: A small number of patients can see increased white blood cells, but also a response to inflammatory activity, but no significant changes in neutrophils, about one-third of patients with anemia, often mild anemia, long-term disease activity or increased female hormones Caused by the effects of hematopoiesis.

5. Serum protein electrophoresis: often 1, 2 and gamma globulin increase, albumin decreases.

6. Serum anti-aortic antibody assay: This method has certain value for the diagnosis of aortitis. Serum anti-aortic antibody titer is 1:32 positive, 1:16 is negative, and the positive rate of aortitis patients can reach 91.5. %, wherein the titer 1:64 accounted for 65%, and the false negative accounted for 8.5%.

Auxiliary inspection

Chest X-ray examination

(1) Cardiac changes: About 1/3 of patients have different degrees of cardiac enlargement, mostly mild left ventricular enlargement, and less severe enlargement, mainly due to increased post-load caused by hypertension; secondly due to aortic valve closure Incomplete or coronary lesions caused by myocardial damage.

(2) changes in the thoracic aorta: often bulging, bulging, dilatation, and even tumor-like dilatation of the ascending aorta or arch descending, may be the effect of hypertension or the performance of aortitis, related to the type and extent of the lesion, Declining the aorta, especially in the middle and lower segment, narrowing adduction and pulsation weakening, etc., is an important indication for extensive stenosis of the thoracic descending aorta. In order to improve the positive rate of diagnosis, the chest photo condition can be increased, such as high-voltage photography. Spreading (or) tomography helps to show such signs.

2. Electrocardiogram examination: About half of the patients have left ventricular hypertrophy, left ventricular strain or high voltage, a few manifestations of coronary insufficiency or myocardial infarction, pulmonary hypertension caused by pulmonary stenosis can be expressed as right ventricular hypertrophy, left ventricular afterload Increased features that may partially mask the right ventricular hypertrophy of the ECG.

3. Fundus examination: A pulse-free fundus is a specific change of the disease, the incidence rate is about 14%, can be divided into three phases: the first phase (vasodiation), optic disc redness, arteriovenous dilation, Congestion, venous lumen unevenness, capillary angiogenesis, small hemorrhage, small hemangioma, iris vitreous normal; stage 2 (anastomotic phase), dilated pupils, disappeared response, iris atrophy, retinal arteriovenous anastomosis, peripheral blood vessels disappear The third phase (complication period), manifested as cataract, retinal hemorrhage and exfoliation.

4. Pulmonary function test: Pulmonary function changes have a certain relationship with pulmonary stenosis and impaired pulmonary blood flow. Ventilation function is reduced by bilateral pulmonary blood flow damage, while diffuse dysfunction is rare, due to long-term pulmonary blood flow damage Decreased lung compliance, or pulmonary hypertension caused by changes in cardiopulmonary function.

5. Blood flow chart examination: The blood flow of the head and limbs can be checked, and the diameter of the arterial lumen can be measured at the same time, which is valuable for diagnosis and understanding of changes in the condition or follow-up observation after surgery.

6. B-mode ultrasonography: The aorta and its main branches can be examined for stenosis or occlusion (carotid artery, subclavian artery, renal artery, etc.), and its distal branch can also be probed.

7. Radionuclide examination: 99mTc-DTPA renal photography and captopril challenge test, when the renal artery stenosis, due to renal ischemia caused by increased renin system activity, angiotensin II makes the glomerulus out of the ball Arteriolar contraction, increased glomerular filtration pressure, compensatory to maintain proper glomerular filtration rate, taking 25mg of captopril, 1 hour after renal examination, if there is renal artery stenosis, due to armor Tannic acid eliminates the contraction of angiotensin II to the small arterioles, so the glomerular filtration rate is lower than before the medication, so as to determine the renal artery stenosis, the positive rate of this method is 96.3%, specificity 82.7% The sensitivity (51.8%) was significantly higher than that of simple kidney photography, but the specificity was not different.

8. CT examination: angiography (including DsA) is still the main method for the diagnosis of arteritis, mainly showing changes in the arterial lumen, but can not observe the changes of the wall is its shortcomings, CT can observe the changes of the arterial wall, the aorta The early diagnosis and pathological activity of inflammation has great value. It can be seen that the wall thickening and calcification, enhanced CT scan, and found that the wall wall enhancement and annular low-density shadow are the active period of the lesion, the angiography is normal, but the wall can be Abnormalities can help early diagnosis of aortitis, especially three-dimensional reconstruction can stereoscopically show the aorta and its main branch lesions, showing the best vascular malformation and complex vascular structure in the overlapping parts.

9. Nuclear Magnetic Resonance (MRI) examination: This method is a non-invasive examination, with multi-position, multi-dimensional imaging ability, rapid imaging sequence using MRI spin echo and gradient echo, can detect aortic luminal lumen and wall morphology Learning and aortic hemodynamic changes can determine aortic regurgitation, this method can show the morphological changes of the intact aorta and its main branches.

10. Angiography

(1) Digital subtraction angiography (DSA): It is a digital image processing system that is injected intravenously with 76% diatrizoate for contrast. It is a better screening method, which is easy to operate and has a small patient burden. The contrast resolution is high, and the lesions in the low-contrast area can also be displayed. Considering that arteritis is the most common cause of renovascular hypertension, the brachial artery, thoracic, abdominal aorta, renal artery, and brachial artery should be treated during angiography. Pulmonary artery examination, generally can replace renal angiography, is also suitable for outpatients, but the renal artery branch lesions are unclear, if necessary, selective renal angiography is still needed.

(2) Selective angiography: the location, extent, extent, distal branch, collateral circulation, and thoracic and abdominal aorta of the renal artery stenosis can be observed.

(3) Coronary angiography: In recent years, the disease has attracted people's attention. Lupi et al reported that the incidence of coronary artery involvement was 9% to 10%. Two patients with young arteritis were found in Fuwai Hospital. Arterial angiography confirmed coronary proximal stenosis, coronary artery bridging was performed, and postoperative biopsy was diagnosed as coronary arteritis.

Japan's Matsubard et al performed coronary angiography analysis in 21 patients with arteritis. According to the pathological features of coronary artery, there were three types: type I is coronary ostia and its proximal stenosis or occlusion. This type is most common; type II is Diffuse type, the lesion can affect the epicardial branch, or involving several segments, the so-called skip lesion; type III is a coronary aneurysm, the latter two types are rare, due to ascending aortic lesions affecting the coronary artery The membrane produces proliferative inflammation, and the smooth muscle of the middle layer contracts to cause coronary artery stenosis or occlusion.

Diagnosis and diagnosis of pediatric arteritis

diagnosis

Hypertension, no pulse or weak pulse and vascular murmur is the main clinical manifestation of this disease. For children with unexplained hypertension, fever, joint pain and erythrocyte sedimentation rate should be considered, and multiple arteritis should be considered. Unexplained persistent fever, should check the pulsation of the great arteries in all parts, measure the blood pressure of the extremities and auscultation of vascular murmurs. The vascular murmur of the lesions is helpful for the diagnosis of this disease, often in the abdomen, the clavicle is concave, the sternum is concave, the sternocleidosis Vascular murmurs are heard on the outside of the spurs and on the lower back. Most of them are continuous, sometimes touching tremors. The occurrence of vascular murmurs is related to vascular stenosis, vascular wall is not smooth and collateral circulation is formed. Selective angiography can determine the location of lesions and range.

Differential diagnosis

The disease should be differentiated from congenital aortic coarctation and renal artery fibrosis.

1. Congenital aortic coarctation: more common in boys, early onset, upper extremity hypertension, lower limb hypotension or undetectable, high vascular murmur position, limited to the anterior region and back, no general inflammatory manifestations, thoracic aortic angiography The narrowed part is in the aortic isthmus.

2. Renal artery fibromuscular dysplasia: It is also more common in women, with renal vascular hypertension, but no vascular murmur and inflammation. Abdominal aortic angiography shows no obvious change of abdominal aorta, distal end of renal artery and its points Branches are affected and bead-like changes, which is different from this disease.

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